FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Kenyon, SJ Luu, JX AF Kenyon, SJ Luu, JX TI Accretion in the early Kuiper Belt. II. Fragmentation SO ASTRONOMICAL JOURNAL LA English DT Article DE Kuiper Belt, Oort cloud; solar system : formation ID ASTEROID COLLISIONAL EVOLUTION; CIRCUMSTELLAR DUST DISK; SLOW-MOVING OBJECTS; OUTER SOLAR-SYSTEM; PLANETESIMAL ACCUMULATION; VELOCITY DISPERSIONS; SIZE DISTRIBUTION; TIME SCALES; PROTOPLANETARY CLOUD; NUMERICAL-SIMULATION AB We describe new planetesimal accretion calculations in the Kuiper Belt that include fragmentation and velocity evolution. All models produce two power-law cumulative size distributions, N(C) proportional to r(-2.5) for radii less than or similar to 0.3-3 km and N(C) proportional to r(-3) for radii greater than or similar to 1-3 km. The power-law indices are nearly independent of the initial mass in the annulus, M(0); the initial eccentricity of the planetesimal swarm, e(0); and the initial size distribution of the planetesimal swarm. The transition between the two power laws moves to larger radii as e(0) increases. The maximum size of objects depends on the intrinsic tensile strength, S(0); Pluto formation requires S(0) greater than or similar to 300 ergs g(-1). The timescale to produce Pluto-sized objects, tau(P), is roughly proportional to M(0)(-1) and e(0) and is less sensitive to other input parameters. Our models yield tau(P) approximate to 30-40 Myr for planetesimals with e(0) = 10(-3) in a minimum mass solar nebula. The production of several "Plutos" and similar to 10(5) Kuiper Belt objects with 50 km radius leaves most of the initial mass in 0.1-10 km radius objects that can be collisionally depleted over the age of the solar system. These results resolve the puzzle of large Kuiper Belt objects in a small-mass Kuiper Belt. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. RP Kenyon, SJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM skenyon@cfa.harvard.edu; luu@strw.leidenuniv.nl OI Kenyon, Scott/0000-0003-0214-609X NR 91 TC 136 Z9 138 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 1999 VL 118 IS 2 BP 1101 EP 1119 DI 10.1086/300969 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 232JZ UT WOS:000082368700045 ER PT J AU Trinchieri, G Israel, GL Chiappetti, L Belloni, T Stella, L Primini, F Fabbiano, P Pietsch, W AF Trinchieri, G Israel, GL Chiappetti, L Belloni, T Stella, L Primini, F Fabbiano, P Pietsch, W TI Broad band X-ray spectra of M31 sources with BeppoSAX SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : individual : M31; galaxies : spiral; X-ray : galaxies ID SATELLITE; EMISSION AB We present the first spectral study of the X-ray emitting stellar sources in M31 in the energy band from similar to 0.1 to 10 keV. We find that the globular cluster sources have spectral characteristics consistent with those of the Milky Way object, namely that the spectrum can be described by a thermal model with similar to 6-20 keV from similar to 2 to 10 keV. Evidence of high absorption in some of these sources is most likely an indication that they lie in or behind the HI ring in the disk of the galaxy. We also find one peculiar globular cluster source, with spectral characteristics more typically associated with either High Mass X-ray Binaries or black hole candidates. We therefore suggest that either the source has been wrongly identified with a globular cluster or that the system contains a Black Hole. We confirm earlier report that the spectrum of the bulge of M31 is consistent with the superposition of many LMXB spectra. It is likely that a large fraction of the similar to 15-30 keV detection obtained from the PDS instrument is associated with the bulge, thus extending the spectral data for this complex of sources up to similar to 30 keV. The high energy part of the spectrum can be parameterized with typical LMXB spectra, while at low energies an additional component is required. No significant variability is observed within the BeppoSAX observation, while a few sources appear to have varied (brightened) since ROSAT and Einstein observations. C1 Osservatorio Astron Brera, I-20121 Milan, Italy. Osservatorio Astron Roma, I-00044 Frascati, Italy. CNR, Ist Fis Cosm G Occhialini, Milan, Italy. Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Max Planck Inst Extraterr Phys, D-85748 Garching, Germany. RP Trinchieri, G (reprint author), Osservatorio Astron Brera, Via Brera 28, I-20121 Milan, Italy. EM ginevra@brera.mi.astro.it OI Chiappetti, Lucio/0000-0001-7857-7908; Israel, GianLuca/0000-0001-5480-6438 NR 30 TC 22 Z9 22 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 1999 VL 348 IS 1 BP 43 EP 62 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 225ZD UT WOS:000081995100013 ER PT J AU Mennickent, RE AF Mennickent, RE TI On the linewidth/K vs. mass ratio relation for SU Ursae Majoris stars and the removal of the inner disk SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE accretion, accretion disks; methods : statistical; stars : binaries : general; stars : evolution; stars : novae, cataclysmic variables ID TIME-RESOLVED SPECTROSCOPY; DWARF NOVA; ACCRETION DISKS; CATACLYSMIC VARIABLES; ORBITAL PERIOD; WZ-SAGITTAE; NUMERICAL SIMULATIONS; PHYSICAL PARAMETERS; VY AQUARII; QUIESCENCE AB We have calibrated the linewidth/K vs. mass ratio relation for SU UMa stars using the "superhump" mass ratio derived from the tidal resonance model. We find that the relation by Jurcevic et al. (1994) is valid for dwarf novae above the period gap but not for SU UMa stars. Under the hypothesis of Keplerian disks, our results are compatible with the removal of the inner disk in SU UMa stars with extreme cycle lengths. The large long-term FWHM variability observed in WZ Sge suggests that the fraction of mass removed from the disk is variable and possibly a function of the supercycle phase. We show a new empirical formula between mass ratio and FWHM/K. It fits the mass ratio of dwarf novae above and below the period gap with a mean relative dispersion of 16% and 26%, respectively, except for the post-period minimum candidates EG Cnc and WZ Sge. C1 Univ Concepcion, Dept Fis, Concepcion, Chile. RP Mennickent, RE (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM rmennick@stars.cfm.udec.cl NR 68 TC 4 Z9 4 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 1999 VL 348 IS 2 BP 364 EP 370 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231DN UT WOS:000082293000009 ER PT J AU Ros, E Marcaide, JM Guirado, JC Ratner, MI Shapiro, II Krichbaum, TP Witzel, A Preston, RA AF Ros, E Marcaide, JM Guirado, JC Ratner, MI Shapiro, II Krichbaum, TP Witzel, A Preston, RA TI High precision difference astrometry applied to the triplet of S5 radio sources B1803+784/Q1928+738/B2007+777 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE techniques : interferometric; astrometry; galaxies : BL Lacertae objects : individual : B1803+784, B2007+777, Q1928+738 ID BL LACERTAE OBJECTS; COMPLETE SAMPLE; SCALE STRUCTURE; MOTION; SYSTEM; MILLIARCSECOND; MAPS; GHZ AB We determined the separations of the radio sources in the triangle formed by the BL Lac objects 1803+784 and 2007+777, and the QSO 1928+738 from intercontinental interferometric observations carried out in November 1991 at the frequencies of 2.3 and 8.4 GHz simultaneously. Difference phase-delay astrometry yielded the following separations: Delta alpha((1803+784)-(1928+738))=-l(h)27(m) 2.(s)811256+/-0.(s)000062 Delta delta((1803+784)-(1928+738))=4 degrees 30' 2." 44833+/-0." 00012 Delta alpha((1928+738)-(2007+777))=-0(h)37(m)42.(s)503305+/-0.(s)000033 Delta delta((1928+738)-(2007+777))=-3 degrees 54'41." 67756+/-0." 00013 Delta alpha((2007+777)-(1803+784))=2(h) 4(m)45.(s)314561+/-0.(s)000052 Delta delta((2007+777)-(1803+784))=-0 degrees 35'20." 77077+/-0." 00013 We successfully connected differenced phase delays over 7 degrees on the sky at 8.4 GHz at an epoch of maximum solar activity. The effects of the ionosphere on these VLBI data were mostly removed by estimates of the total electron content from observations of GPS satellites. The comparison of the estimated separation of QSO 1928+738 and BL 2007+777 with previous such estimates obtained from data at different epochs leads us to a particular alignment of the maps of QSO 1928+738 at different epochs relative to those of BL 2007+777, although with significant uncertainty. For this alignment, that the jet components of QSO 1928+738 show a mean proper motion of 0.32+/-0.10 mas/yr and also suggest an identification for the position of the core of this radio source. C1 Max Planck Inst Radioastron, D-53121 Bonn, Germany. Univ Valencia, Dept Astron & Astrofis, E-46100 Valencia, Spain. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ros, E (reprint author), Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany. EM ros@mpifr-bonn.mpg.de NR 47 TC 17 Z9 17 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 1999 VL 348 IS 2 BP 381 EP 393 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231DN UT WOS:000082293000011 ER PT J AU Mennickent, RE Matsumoto, K Arenas, J AF Mennickent, RE Matsumoto, K Arenas, J TI The orbital period of the dwarf nova HS Virginis, the revised P-o-P-s relation and the "superhump" mass ratio distribution of SU UMa stars SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : individual: HS Vir; stars : novae, cataclysmic variables; stars : fundamental parameters; stars : evolution; stars : binaries : general ID URSAE-MAJORIS STARS; CATACLYSMIC VARIABLES; ACCRETION DISKS; NUMERICAL SIMULATIONS; RADIAL-VELOCITY; LINE EMISSION; TIME-SERIES; BINARIES; MODEL; APPROXIMATIONS AB A spectroscopic study of the SU UMa star HS Vir is presented. From the analysis of the radial velocities of the H alpha emission line the most likely orbital period is 0.(d)07692(3), although we cannot discard two aliases at 0.(d)07678 and 0.(d)07709. The Balmer lines follow the orbital period with a radial velocity semiamplitude K = 96 +/- 9 km s(-1), but the He I lambda 5875 emission line shows a double wave during the orbital cycle. We found that the mean Balmer, He I and He II 4686 lines can be roughly modeled with a disk radial emissivity proportional to r(-2). A revised version of the P-o - P-s relation for SU UMa stars is also given, which is relevant for discriminating between +/- 1 c/d aliases of the orbital period. We calculated the mass ratio, derived from the tidal resonance model, of HS Vir (q(sh) = 0.22 +/- 0.04) and 43 additional SU UMa stars. The q(sh) distribution has a roughly gaussian shape with a mean 0.14, in sharp contrast with the orbital period distribution. Finally, a discussion of the possible stellar masses and inclination of HS Vir is given. We observe that the mass ratio derived from the dynamic solution is in disagreement with that derived from the tidal resonance model. This fact probably indicates that It does not represent the white dwarf binary motion. C1 Univ Concepcion, Dept Fis, Concepcion, Chile. Kyoto Univ, Fac Sci, Dept Astron, Kyoto 6068502, Japan. Univ Keele, Dept Phys, Keele ST5 5BG, Staffs, England. RP Mennickent, RE (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM rmennick@stars.cfm.udec.cl; katsura@kusastro.kyoto-u.ac.jp; jla@astro.keele.ac.uk NR 50 TC 10 Z9 10 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 EI 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 1999 VL 348 IS 2 BP 466 EP 474 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231DN UT WOS:000082293000018 ER PT J AU Tafalla, M Myers, PC Mardones, D Bachiller, R AF Tafalla, M Myers, PC Mardones, D Bachiller, R TI A cluster of young stellar objects in L1211 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : formation; ISM : clouds; ISM : dust, extinction; ISM : individual objects : L1211; ISM : jets and outflows; ISM : molecules ID SPECTRAL ENERGY-DISTRIBUTIONS; BIPOLAR MOLECULAR OUTFLOWS; STAR-FORMATION; CEPHEUS OB3; CONTINUUM OBSERVATIONS; IRAS SOURCES; DENSE CORES; COLD DUST; CLOUDS; EMISSION AB We present millimeter continuum and line observations of a dense core in L1211, a member of the Cepheus cloud complex. We find a small cluster of at least 4 millimeter (mm) sources with no optical counterpart, but each associated with near infrared (NIR) diffuse emission. The strongest mm source has no NIR point-like counterpart, and constitutes a good candidate for a Class 0 object. The other mm objects seem associated with NIR sources and most likely belong to Class I, as also suggested by the spectral energy distributions derived from combining our mm data with IRAS HIRES fluxes. As evidenced by our line data, the mm sources are embedded in an elongated, turbulent core of about 150 M. of mass and 0.6 pc length. Two of the millimeter sources power bipolar molecular outflows, another signature of their extreme youth. The outflows are well resolved by our observations and seem to have unrelated orientations. The combination of millimeter sources and bipolar outflow emission indicates that multiple star formation in L1211 has occurred during a short period of time (a few 10(5) yr). The lack of a noticeable enhancement in the number of NIR sources suggests that the core has not had enough time to form a cluster, so we infer that L1211 is undergoing a first episode of star formation. C1 Observ Astron Nacl, E-28800 Alcala De Henares, Spain. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Chile, Dept Astron, Santiago, Chile. RP Tafalla, M (reprint author), Observ Astron Nacl, Apartado 1143, E-28800 Alcala De Henares, Spain. EM tafalla@oan.es; pmyers@cfa.harvard.edu; mardones@das.uchile.cl; bachiller@oan.es RI Mardones, Diego/I-5719-2016 NR 57 TC 11 Z9 11 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 1999 VL 348 IS 2 BP 479 EP 486 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231DN UT WOS:000082293000020 ER PT J AU Marengo, M Busso, M Silvestro, G Persi, P Lagage, PO AF Marengo, M Busso, M Silvestro, G Persi, P Lagage, PO TI Mid-infrared colors as a diagnostic tool of circumstellar envelopes in AGB stars SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : AGB and post-AGB; stars : circumstellar matter; stars : individual : 0191-B2B; infrared : stars ID ASYMPTOTIC GIANT BRANCH; LONG-PERIOD VARIABLES; INTERMEDIATE-MASS STARS; M-MIRA VARIABLES; DUST SHELLS; CARBON STARS; C-STARS; PREPLANETARY NEBULAE; MOLECULAR-EMISSION; LOSS RATES AB New observations of AGE circumstellar envelopes made with the mid-IR imaging camera CAMIRAS are presented. Diagnostic tools based on mid-IR colors are proposed for the analysis of the observed objects, and tested against a larger sample of AGE sources derived from IRAS observations. Radiative transfer modelling is used to calibrate our diagnostic procedures, in order to investigate the physical and chemical characteristics of both samples. The different chemical signatures of C-rich and O-rich envelopes are put in evidence by mid-IR color-color diagrams, and correlations are found between the observed colors and a mass loss parameter derived by radio observations. Evidences for possible temporal variations in the mass loss rates are also suggested. The possibility to derive direct information on the spatial structure and symmetry of the envelopes is finally investigated, and the image of the O-rich star WX Psc, as an example of a spatially resolved axisymmetric enveloper is presented. C1 SISSA, I-34014 Trieste, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron Torino, I-10025 Pino Torinese, Italy. Univ Turin, Dipartimento Fis Gen, I-10124 Turin, Italy. CNR, Ist Astrofis Spaziale, Rome, Italy. CEA Saclay, Serv Astrophys, DAPNIA, DSM, F-91191 Gif Sur Yvette, France. RP Marengo, M (reprint author), SISSA, I-34014 Trieste, Italy. RI Busso, Maurizio Maria/K-7075-2015 OI Busso, Maurizio Maria/0000-0001-8944-5820 NR 61 TC 14 Z9 14 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 1999 VL 348 IS 2 BP 501 EP 511 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231DN UT WOS:000082293000022 ER PT J AU Lee, Y Jung, JH Chung, HS Kim, HG Park, YS Kim, HR Kim, BG Kim, J Han, ST AF Lee, Y Jung, JH Chung, HS Kim, HG Park, YS Kim, HR Kim, BG Kim, J Han, ST TI Galactic anticenter CO survey - I. Area l = 178 degrees to 186 degrees, b = 3.degrees 5 to 6 degrees SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE ISM : clouds; ISM : abundance; ISM : dust; ISM : HII regions ID GALAXY MOLECULAR CLOUDS; OUTER GALAXY; (CO)-C-13 SURVEY; SOLAR CIRCLE; IRAS SOURCES; MILKY-WAY; EMISSION; REGIONS; QUADRANT; COMPLEX AB We have mapped a 17 square-degree section (l,b) = (178.degrees 0 similar to 186.degrees 0, 3.degrees 5 similar to 6.degrees 0) of the Galactic Anticenter region in the (CO)-C-12 J = 1 - 0 line using the 3-mm SIS receiver on the 14-m telescope at the Taeduk Radio Astronomy Observatory. A total of 7000 spectra has been obtained with a grid spacing of 3'. The results of the observations are presented in the form of I - b and v - b contour maps. Molecular emission of the mapped area is found to be very extended and matches with the FIR emission boundary. The radial velocity of the molecular gas is found to be within the range of (LSR)-L-v = -25 similar to +10 km s(-1). We also found several small clouds located at 1 = 180 degrees, b = 5 degrees similar to 6 degrees having (LSR)-L-v = -20 km s(-1), which is quite anomalous in this direction. We identified 30 individual clouds within the mapped region with an arbitrary threshold temperature using a cloud identification code. Twelve subclouds were also identified from the largest cloud with a higher threshold temperature. The ratio of dust emission to CO integrated intensity for the Galactic Anticenter region is found to be similar to that of the dark clouds in solar neighborhood, and much less than that of giant molecular clouds, implying that the heating source within the clouds is minimal. C1 Taeduk Radio Astron Observ, Korea Astron Observ, Taejon 305348, South Korea. RP Lee, Y (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS-78, Cambridge, MA 02138 USA. NR 46 TC 6 Z9 6 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD AUG PY 1999 VL 138 IS 2 BP 187 EP 202 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 225XV UT WOS:000081992000001 ER PT J AU Dupree, AK Whitney, BA Pasquini, L AF Dupree, AK Whitney, BA Pasquini, L TI Evolution of chromospheric activity: M67 red giants SO ASTROPHYSICAL JOURNAL LA English DT Article DE open clusters and associations : individual (M67); stars : chromospheres; stars : mass loss ID OPEN CLUSTER M67; OLD OPEN CLUSTERS; LATE-TYPE STARS; CA-II H; MAIN-SEQUENCE STARS; INTERSTELLAR NA-I; MAGNETIC-STRUCTURE; COOL STARS; MASS-LOSS; LINE AB Echelle spectra of the Ca II H- and K-line region (lambda 3950) of 15 red giant stars in the open cluster M67 reveal atmospheric dynamics and determine chromospheric radiative losses in order to assess chromospheric heating requirements and to follow the evolution of chromospheric activity. M67 red giants in conjunction with giants in younger clusters create a continuous group of red giants in the color-magnitude diagram, with 0.1 less than or equal to (B-V) less than or equal to 1.65 along the red giant branch. M67 contains the more evolved clump giants as well. Asymmetric line emission cores, indicative of outflowing material, are found in a majority of the M67 giants on the red giant branch and occur over the complete sample, from M-V = -0.8 to M-V = 1.9, suggesting that outward mass motions are well established at these luminosities. Radiative losses, as measured by emission strengths from Ca II, decrease smoothly with decreasing stellar effective temperature in M67 and connect well to a combined sample of warmer cluster giants (NGC 2477, IC 4756, and the Hyades) with M less than or equal to 3 M. studied by Beasley & Cram. Stellar effective temperature predominantly determines the level of chromospheric Ca II losses for giants with M less than or equal to 3 M,. No evidence is found for a sharp decline in the flux of Ca II predicted by the Rutten & Pylyser magnetic model for chromospheric heating. However, emission in held giants (which tend to be younger) suggests that sharp declines in surface flux with decreasing effective temperature characteristic of pure magnetic activity occur for ion species more highly excited than Ca II. Although acoustic models for chromospheric heating apparently agree with the measured Ca Ir flux levels for the coolest giants, additional heating processes must be present in warmer giants and clump stars. Clump giants exhibit Ca II fluxes consistent with stars of similar colors on the red giant branch, suggesting a renaissance in chromospheric heating occurs after evolution beyond the red giant branch. Chromospheric heating in the giants of solar metallicity is likely to be derived from multiple sources, both hydrodynamic causes as well as magnetically related processes. The relative contribution of each heating mechanism changes with temperature in the stellar atmosphere, and these proportions may change during a star's evolution from the main sequence. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. European So Observ, D-85748 Garching, Germany. RP Dupree, AK (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 61 TC 23 Z9 23 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1999 VL 520 IS 2 BP 751 EP 762 DI 10.1086/307504 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218EQ UT WOS:000081540600035 ER PT J AU Psaltis, D Wijnands, R Homan, J Jonker, PG Van der Klis, M Miller, MC Lamb, FK Kuulkers, E van Paradijs, J Lewin, WHG AF Psaltis, D Wijnands, R Homan, J Jonker, PG Van der Klis, M Miller, MC Lamb, FK Kuulkers, E van Paradijs, J Lewin, WHG TI On the magnetospheric beat-frequency and lense-thirring interpretations of the horizontal-branch oscillation in the Z sources SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; X-rays : stars ID QUASI-PERIODIC OSCILLATIONS; X-RAY BINARIES; MAGNETIC NEUTRON-STARS; DISCOVERY; FLUX; PULSAR; GX5-1; A0535+262; ACCRETION; BEHAVIOR AB Three types of quasi-periodic oscillations (QPOs) have been discovered so far in the persistent emission of the most luminous neutron star low-mass X-ray binaries, the Z sources: similar to 10-60 Hz horizontal-branch and similar to 6-20 Hz normal/flaring-branch oscillations and similar to 200-1200 Hz kilohertz QPOs, which usually occur in pairs. Here we study the horizontal-branch oscillations and the two simultaneous kilohertz QPOs, which were discovered using the Rossi X-Ray Timing Explorer, comparing their properties in five Z sources with the predictions of the magnetospheric beat-frequency and Lense-Thirring precession models. We find that the variation of the horizontal-branch oscillation frequency with accretion rate predicted by the magnetospheric beat-frequency model for a purely dipolar stellar magnetic field and a radiation-pressure-dominated inner accretion disk is consistent with the observed variation. The model predicts a universal relation between the horizontal-branch oscillation, stellar spin, and upper kilohertz QPO frequencies that agrees with the data on five Z sources. The model implies that the neutron stars in the Z sources are near magnetic spin equilibrium, that their magnetic field strengths are similar to 10(9)-10(10) G, and that the critical fastness parameter for these sources is greater than or similar to 0.8. If the frequency of the upper kilohertz QPO is an orbital frequency in the accretion disk, the magnetospheric beat-frequency model requires that a small fraction of the gas in the disk does not couple strongly to the stellar magnetic field at 3-4 stellar radii but instead drifts slowly inward in nearly circular orbits until it is within a few kilometers of the neutron star surface. The Lense-Thirring precession model is consistent with the observed magnitudes of the horizontal-branch oscillation frequencies only if the moments of inertia of the neutron stars in the Z sources are similar to 4-5 times larger than the largest values predicted by realistic neutron star equations of state. If instead the moments of inertia of neutron stars have the size expected and their spin frequencies in the Z sources are approximately equal to the frequency separation of the kilohertz QPOs, Lense-Thirring precession can account for the magnitudes of the horizontal-branch oscillation frequencies only if the fundamental frequency of the horizontal-branch oscillation is at least 4 times the precession frequency. We argue that the change in the slope of the correlation between the frequency of the horizontal-branch oscillation and the frequency of the upper kilohertz QPO, when the latter is greater than 850 Hz, is directly related to the varying frequency separation of the kilohertz QPOs. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Illinois, Dept Phys & Astron, Urbana, IL 61801 USA. Univ Oxford, Nucl & Astrophys Lab, Oxford OX1 3RH, England. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Space Res Ctr, Cambridge, MA 02139 USA. RP Psaltis, D (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM dpsaltis@cfa.harvard.edu; rudy@astro.uva.nl; homan@astro.uva.nl; peterj@astro.uva.nl; michiel@astro.uva.nl; miller@bayes.uchicago.edu; f-lamb@uiuc.edu; e.kuulkers1@physics.oxford.ac.uk; jvp@astro.uva.nl; lewin@space.mit.edu NR 52 TC 58 Z9 58 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1999 VL 520 IS 2 BP 763 EP 775 DI 10.1086/307460 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218EQ UT WOS:000081540600036 ER PT J AU Sobczak, GJ McClintock, JE Remillard, RA Bailyn, CD Orosz, JA AF Sobczak, GJ McClintock, JE Remillard, RA Bailyn, CD Orosz, JA TI RXTE spectral observations of the 1996-1997 outburst of the microquasar GRO J1655-40 SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; stars : individual (GRO J1655-40); X-rays : stars ID ADVECTION-DOMINATED ACCRETION; X-RAY BINARIES; BLACK-HOLES; SUPERLUMINAL SOURCE; INTERMEDIATE STATE; CYGNUS X-1; DISKS; DISKOSEISMOLOGY; GRS-1915+105; GX-339-4 AB Excellent coverage of the entire 16 month 1996-1997 outburst cycle of GRO J1655-40 was provided by the Rossi X-Ray Timing Explorer (RXTE). We present a full spectral analysis of these data, which includes 52 Proportional Counter Array spectra from 2.5 to 20 keV and High Energy X-Ray Timing Experiment spectra above 20 keV. We also include a nearly continuous All-Sky Monitor light curve with several intensity measurements per day. The data are interpreted in the context of the multicolor blackbody disk/power-law model. The source exhibits two principal outburst states which we associate with the very high and the high/soft states. During the very high state, the spectrum is often dominated by a power-law component with photon index (Gamma) similar to 2.3-2.7. The source exhibits intense hard hares on timescales of hours to days which are correlated with changes in both the fitted temperature and radius of the inner accretion disk. During the high/soft state, the spectrum is dominated by the soft thermal emission from the accretion disk with spectral parameters that suggest approximately constant inner disk radius and temperature. The power-law component is relatively weak with Gamma similar to 2-3. During the last few observations, the source undergoes a transition to the low/hard state. We find that a tight relationship exists between the observed inner radius of the disk and the flux in the power-law component. During intense hard flares, the inner disk radius is observed to decrease by as much as a factor of 3 on a timescale of days. The apparent decrease of the inner disk radius observed during the hares may be due to the failure of the multicolor disk model caused by a steepening of the radial temperature profile in the disk coupled with increased spectral hardening and not physical changes of the inner disk radius. The distortion of the inner disk spectrum by the power-law hares indicates that the physical mechanism responsible for producing the power-law emission is linked to the inner disk region. Assuming that our spectral model is valid during periods of weak power-law emission, our most likely value for the inner disk radius implies a* < 0.7 Such a low value for the black hole angular momentum is inconsistent with the relativistic frame dragging and the "diskoseismic" models as interpretations for the 300 Hz X-ray QPO seen during some of these RXTE observations. C1 Harvard Univ, Dept Astron, Cambridge, MA 02138 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Yale Univ, Dept Astron, New Haven, CT 06520 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. RP Sobczak, GJ (reprint author), Harvard Univ, Dept Astron, 60 Garden St, Cambridge, MA 02138 USA. EM gsobczak@cfa.harvard.edu; jem@cfa.harvard.edu; rr@space.mit.edu; bailyn@astro.yale.edu; orosz@astro.psu.edu NR 49 TC 87 Z9 87 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1999 VL 520 IS 2 BP 776 EP 787 DI 10.1086/307474 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218EQ UT WOS:000081540600037 ER PT J AU Gruzinov, A Quataert, E AF Gruzinov, A Quataert, E TI The proton distribution function in weakly magnetized turbulent plasmas SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; plasmas; turbulence ID ADVECTION-DOMINATED ACCRETION; ALFVENIC TURBULENCE; BLACK-HOLES; ORIGIN; FLOWS AB We calculate the proton distribution function due to heating by subsonic, Alfvenic turbulence in a weakly magnetized collisionless plasma. The distribution function is nonthermal. For nonrelativistic energies it is an exponential of the magnitude of the proton velocity. For ultrarelativistic energies, it can be characterized as a power law with a momentum-dependent slope. We briefly discuss the implications of this work for gamma-ray emission (via pion decay) from hot accretion flows. C1 Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Gruzinov, A (reprint author), Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. NR 12 TC 9 Z9 9 U1 1 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1999 VL 520 IS 2 BP 849 EP 852 DI 10.1086/307472 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218EQ UT WOS:000081540600045 ER PT J AU Gibson, SE Biesecker, D Guhathakurta, M Hoeksema, JT Lazarus, AJ Linker, J Mikic, Z Pisanko, Y Riley, P Steinberg, J Strachan, L Szabo, A Thompson, BJ Zhao, XP AF Gibson, SE Biesecker, D Guhathakurta, M Hoeksema, JT Lazarus, AJ Linker, J Mikic, Z Pisanko, Y Riley, P Steinberg, J Strachan, L Szabo, A Thompson, BJ Zhao, XP TI The three-dimensional coronal magnetic field during Whole Sun Month SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; solar wind; Sun : corona; Sun : magnetic fields ID FARADAY-ROTATION MEASUREMENTS; SOLAR-WIND; SHEET CURRENTS; MODEL; MINIMUM; TEMPERATURE; EVOLUTION; STREAMER; PLASMA; VOLUME AB Combining models and observations, we study the three-dimensional coronal magnetic field during a period of extensive coordinated solar observations and analysis known as the Whole Sun Month (WSM) campaign (1996 August 10-September 8). The two main goals of the WSM campaign are addressed in this paper, namely, (1) to use the field configuration to link coronal features observed by coronagraphs and imaging telescopes to solar wind speed variations observed in situ and (2) to study the role of the three-dimensional coronal magnetic field in coronal force balance. Specifically, we consider how the magnetic field connects the two fastest wind streams to the two regions that have been the main foci of the WSM analysis: the equatorial extension of the north coronal hole (known as the Elephant's Trunk) and the axisymmetric streamer belt region on the opposite side of the Sun. We then quantitatively compare the different model predictions of coronal plasma and solar wind properties with observations and consider the implications for coronal force balance and solar wind acceleration. C1 Catholic Univ Amer, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Stanford Univ, Stanford, CA 94305 USA. MIT, Cambridge, MA 02139 USA. Inst Appl Geophys, Moscow, Russia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Gibson, SE (reprint author), Univ Cambridge, Dept Appl Math & Theoret Phys, Silver St, Cambridge CB3 9EW, England. RI Gibson, Sarah/A-9189-2011; Thompson, Barbara/C-9429-2012 NR 63 TC 31 Z9 32 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1999 VL 520 IS 2 BP 871 EP 879 DI 10.1086/307496 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218EQ UT WOS:000081540600048 ER PT J AU Navascues, DBY Stauffer Jr Song I Caillault, JP AF Navascues, DBY Stauffer, JR Song, I Caillault, JP TI The age of beta Pictoris SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; stars : individual (beta Pictoris); stars : kinematics ID URSA-MAJOR GROUP; EVOLUTIONARY STATUS; CIRCUMSTELLAR DISK; MULTIPLE STARS; CATALOG; SUBMILLIMETER; PHOTOMETRY; VELOCITIES; FOMALHAUT; SYSTEMS AB We have reanalyzed data for the proposed moving group associated with beta Pictoris in order to determine if the group (or part of it) is real and, if so, to derive an improved age estimate for beta Pie. By using new, more accurate proper motions from PPM and Hipparcos and a few new radial velocities, we conclude that on kinematic grounds, most of the proposed members of the moving group are not, in fact, associated with beta Pie. However, two M dwarfs-or three, actually, since one of them is a nearly equal mass binary-have space motions that coincide with that of beta Pic to within 1 km s(-1) with small error bars. Based on a color-magnitude diagram derived from accurate photometry and Hipparcos parallaxes, these two possible proper-motion companions to beta Pic are very young; we derive an age of similar to 20 Myr by comparison with theoretical tracks from F. D'Antona & I. Mazzitelli. In fact, the proposed beta Pic companions comprise two of the three youngest M dwarfs in the sample of 160 dM stars for which we have data. The chromospheric and coronal activities of these two stars also confirm that they are quite young. We argue that the probability that two of the three youngest nearby M dwarfs would accurately share the space motion of beta Pic by chance is quite small, and therefore we believe that beta Pic and the two M dwarfs (GL 799 and GL 803) were formed together. The estimated age for beta Pic is then 20 +/- 10 Myr, where the uncertainty in the age arises primarily from possible errors in the pre-main-sequence isochrones and in the conversion from color to effective temperature. This young age for beta Pic supports the contention that the IR excess for the Vega-like stars is age dependent. C1 Max Planck Inst Astron, D-69117 Heidelberg, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. RP Navascues, DBY (reprint author), Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany. RI Barrado Navascues, David/C-1439-2017 OI Barrado Navascues, David/0000-0002-5971-9242 NR 40 TC 129 Z9 129 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1999 VL 520 IS 2 BP L123 EP L126 DI 10.1086/312162 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218ER UT WOS:000081540700012 ER PT J AU Rybicki, GB Loeb, A AF Rybicki, GB Loeb, A TI Polarization of the Ly alpha halos around sources before cosmological reionization SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; line : profiles ID FIELD AB In Loeb & Rybicki (hereafter Paper I), it was shown that before reionization, the scattering of Ly alpha photons from a cosmological source might lead to a fairly compact (similar to 15 ") Ly alpha halo around the source. Observations of such halos could constrain the properties of the neutral intergalactic medium and, in particular, yield the cosmological density parameters of baryons and matter on scales where the Hubble flow is unperturbed. Paper I did not treat the polarization of this scattered radiation but did suggest that the degree of such polarization might be large. In this Letter, we report on improved calculations for these Ly alpha halos, now accounting for the polarization of the radiation field. The polarization is linear and is oriented tangentially to the projected displacement from the center of the source. The degree of polarization is found to be 14% at the core radius, where the intensity has fallen to half of the central value. It rises to 32% and 45% at the radii where the intensity has fallen to one-tenth and one-hundredth of the central intensity, respectively. At larger radii, the degree of polarization rises further, asymptotically to 60%. Such high values of polarization should be easily observable and provide a clear signature of the phenomenon of Ly alpha halos surrounding sources prior to reionization. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Rybicki, GB (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 16 TC 18 Z9 18 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1999 VL 520 IS 2 BP L79 EP L81 DI 10.1086/312155 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218ER UT WOS:000081540700001 ER PT J AU van Dokkum, PG Franx, M Fabricant, D Kelson, DD Illingworth, GD AF van Dokkum, PG Franx, M Fabricant, D Kelson, DD Illingworth, GD TI A high merger fraction in the rich cluster MS 1054-03 at z=0.83: Direct evidence for hierarchical formation of massive galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (MS 1054-03); galaxies : elliptical and lenticular, cD; galaxies : evolution; galaxies : structure ID DISTANT CLUSTERS; CLOSE PAIRS; EVOLUTION; POPULATIONS; PHOTOMETRY; MORPHOLOGY; REDSHIFT; COMA AB We present a morphological study of the galaxy population of the luminous X-ray cluster MS 1054-03 at z = 0.83. The sample consists of 81 spectroscopically confirmed cluster members in a 3 x 2 h(50)(-1) Mpc area imaged in F606W and F814W with WFPC2. We find 13 ongoing mergers in MS 1054-03, comprising 17% of the L greater than or similar to L-* cluster population. Most of these mergers will likely evolve into luminous (similar to 2L(*)) elliptical galaxies, and some may evolve into SO galaxies. Assuming the galaxy population in MS 1054-03 is typical for its redshift, it is estimated that similar to 50% of present-day cluster elliptical galaxies experienced a major merger at z<1. The mergers are preferentially found in the outskirts of the cluster and probably occur in small infalling clumps. Morphologies, spectra, and colors of the mergers show that their progenitors were typically E/S0 or early-type spiral galaxies with mean stellar formation redshifts z(*) greater than or similar to 1.7. The red colors of the mercer remnants are consistent with the low scatter in the color-magnitude relation in rich clusters at lower redshift. The discovery of a high fraction of mergers in this young cluster is direct evidence against formation of elliptical galaxies in a single "monolithic" collapse at high redshift and is in qualitative agreement with predictions of hierarchical models for structure formation. C1 Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. Leiden Observ, NL-2300 RA Leiden, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02318 USA. Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. RP van Dokkum, PG (reprint author), Kapteyn Astron Inst, POB 800, NL-9700 AV Groningen, Netherlands. NR 30 TC 192 Z9 192 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1999 VL 520 IS 2 BP L95 EP L98 DI 10.1086/312154 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218ER UT WOS:000081540700005 ER PT J AU Bushmann, PJ AF Bushmann, PJ TI Concurrent signals and behavioral plasticity in blue crab (Callinectes sapidus Rathbun) courtship SO BIOLOGICAL BULLETIN LA English DT Article ID LOBSTER HOMARUS-AMERICANUS; CRAYFISH PROCAMBARUS-CLARKII; SEX-PHEROMONE; AGONISTIC INTERACTIONS; RESPONSES; CUES; RECOGNITION; CRUSTACEA; ORIENTATION; COMPETITION AB Behavioral flexibility and behavioral regulation through courtship signals may both contribute to mating success. Blue crabs (Callinectes sapidus) form precopulatory pairs after courtship periods that are influenced by female and perhaps male urine-based chemical signals. In this study, male and female crabs were observed in 1.5-m circular outdoor pools for 45 min while the occurrence and sequence of courtship behaviors and pairing outcomes were recorded. These results were then compared with trials in which males or females were blindfolded; lateral antennule (outer flagellum) ablated; blindfolded and lateral antennule ablated; or had received nephropore blocks. The relative importance of visual and chemical sensory systems during blue crab courtship were then determined and urine and non-urine based chemical signals for both males and females were examined. Courtship behaviors varied considerably in occurrence and sequence; no measured behavior was necessary for pairing success. Male or female blindfolding had no effect on any measured behavior. Males and females required chemical information for normal courtship behaviors, yet blocking male or female urine release did not affect courtship behaviors. Males required chemical information to initiate pairing or to maintain stable pairs. Male urine release was necessary for stable pairing, suggesting that male urine signals may be involved in pair maintenance rather than pair formation. Females that could not receive chemical information paired faster and elicited fewer male agonistic behaviors. The results demonstrate a great; variability and flexibility in blue crab courtship, with no evidence for stereotyped behavioral sequences. However, these behaviors appear regulated by urine- and nonurine-based redundant chemical signals emanating from both males and females. Although urine-based signals play roles in blue crab courtship, chemical signals from other sites appear to carry sufficient information to elicit a full range of behavioral responses in males and females. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Bushmann, PJ (reprint author), Anne Arundel Community Coll, 101 Coll Pkwy, Arnold, MD 21012 USA. NR 66 TC 28 Z9 31 U1 3 U2 9 PU MARINE BIOLOGICAL LABORATORY PI WOODS HOLE PA 7 MBL ST, WOODS HOLE, MA 02543 USA SN 0006-3185 J9 BIOL BULL JI Biol. Bull. PD AUG PY 1999 VL 197 IS 1 BP 63 EP 71 DI 10.2307/1542997 PG 9 WC Biology; Marine & Freshwater Biology SC Life Sciences & Biomedicine - Other Topics; Marine & Freshwater Biology GA 233AM UT WOS:000082403400008 PM 28296500 ER PT J AU Basset, Y Novotny, V AF Basset, Y Novotny, V TI Species richness of insect herbivore communities on Ficus in Papua New Guinea SO BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Article DE Auchenorrhyncha; host plant; leaf-chewing insects; Lepidoptera; Moraceae; sap-sucking insects; rain forest ID TAXONOMIC ISOLATION; ECOLOGICAL COMMUNITIES; REGIONAL PROCESSES; PLANT DEFENSE; FIG TREES; EVOLUTION; ARTHROPODS; AFRICAN; FOREST; LATEX AB Insect herbivores were sampled from the foliage of 15 species of Ficus (Moraceae) in rainforest and coastal habitats in the Madang area, Papua New Guinea. The collection included 13 193 individuals representing 349 species of leaf-chewing insects and 44 900 individuals representing 430 species of sap-sucking insects. Despite a high sampling intensity, the species accumulation curve did not reach an asymptote. This pattern was attributed to the highly aggregated distribution of insects on individual host trees. The number of insect species collected on a particular Ficus species ranged from 34 to 129 for leaf-chewing and from 51 to 219 for sap-sucking insects. Two Ficus species growing on the seashore sustained less speciose insect communities than their counterparts growing in forest. For the forest figs, significant predictors of insect species richness included leaf palatability and leaf production for leaf-chewing insects (40% of the variance explained), and tree density and leaf expansion for sap-sucking insects (75%). The high faunal overlap among Ficus communities and the importance of local resources for insect herbivores suggest that highly specialized interactions between insect herbivores and Ficus in Papua New Guinea have not been conserved in evolutionary time. This is at variance with the dogma of old, extremely specialized and conservative interactions between insect herbivores and their hosts, providing numerous ecological niches in the floristically rich tropics. (C) 1999 The Linnean Society of London. C1 Smithsonian Trop Res Inst, Balboa, Ancon, Panama. Univ S Bohemia, Inst Entomol CAS, Ceske Budejovice 37005, Czech Republic. Univ S Bohemia, Fac Biol, Ceske Budejovice 37005, Czech Republic. Bishop Museum, Dept Nat Sci, Honolulu, HI USA. RP Novotny, V (reprint author), Insect Ecol Project, POB 604, Madang, Papua N Guinea. RI Basset, Yves/B-6642-2014; Novotny, Vojtech/G-9434-2014 OI Novotny, Vojtech/0000-0001-7918-8023 NR 74 TC 60 Z9 63 U1 2 U2 21 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0024-4066 J9 BIOL J LINN SOC JI Biol. J. Linnean Soc. PD AUG PY 1999 VL 67 IS 4 BP 477 EP 499 DI 10.1111/j.1095-8312.1999.tb01943.x PG 23 WC Evolutionary Biology SC Evolutionary Biology GA 227TX UT WOS:000082097000002 ER PT J AU Basset, Y AF Basset, Y TI Diversity and abundance of insect herbivores foraging on seedlings in a rainforest in Guyana SO ECOLOGICAL ENTOMOLOGY LA English DT Article DE Catostemma; Chlorocardium; Eperua; Guyana; host specificity; Mora; Pentaclethra; seedling; species richness ID SPECIES RICHNESS; TROPICAL TREE; RAIN-FOREST; ARTHROPODS; ARCHITECTURE; TEMPERATE; COMMUNITY; DISTANCE; SAPLINGS; FOLIAGE AB 1. Free-Living insect herbivores foraging on 10000 tagged seedlings representing five species of common rainforest trees were surveyed monthly for more than 1 year in an unlogged forest plot of 1 km(2) in Guyana. 2. Overall, 9056 insect specimens were collected. Most were sap-sucking insects, which represented at least 244 species belonging to 25 families. Leaf-chewing insects included at least 101 species belonging to 16 families. Herbivore densities were among the lowest densities reported in tropical rainforests to date: 2.4 individuals per square metre of foliage. 3. Insect host specificity was assessed by calculating Lloyd's index of patchiness from distributional records and considering feeding records in captivity and in situ. Generalists represented 84 and 78% of sap-sucking species and individuals, and 75 and 42% of leaf-chewing species and individuals. In particular, several species of polyphagous xylem-feeding Cicadellinae were strikingly abundant on all hosts. 4. The high incidence of generalist insects suggests that the Janzen-Connell model, explaining rates of attack on seedlings as a density-dependent process resulting from contagion of specialist insects from parent trees, is unlikely to be valid in this study system. 5. Given the rarity of flushing events for the seedlings during the study period, the low insect densities, and the high proportion of generalists, the data also suggest that seedlings may represent a poor resource for free-living insect herbivores in rainforests. C1 CABI Biosci Environm, Ascot, Berks, England. RP Basset, Y (reprint author), Smithsonian Trop Res Inst, Apartado 2072, Balboa, Ancon, Panama. RI Basset, Yves/B-6642-2014 NR 50 TC 31 Z9 33 U1 1 U2 6 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0307-6946 J9 ECOL ENTOMOL JI Ecol. Entomol. PD AUG PY 1999 VL 24 IS 3 BP 245 EP 259 DI 10.1046/j.1365-2311.1999.00197.x PG 15 WC Entomology SC Entomology GA 234MY UT WOS:000082489500001 ER PT J AU Drent, J Lichtenbelt, WDV Wikelski, M AF Drent, J Lichtenbelt, WDV Wikelski, M TI Effects of foraging mode and season on the energetics of the Marine Iguana, Amblyrhynchus cristatus SO FUNCTIONAL ECOLOGY LA English DT Article DE daily energy expenditure; doubly labelled water; Galapagos; temperature; water flux ID POPULATION BIOLOGY; LIZARDS; TEMPERATURE; ENVIRONMENT; AUSTRALIA; FECUNDITY; FIELD; CRASH; SIZE AB 1, Marine Iguanas (Amblyrhynchus cristatus) inhabiting the rocky shores of the Galapagos Islands apply two foraging strategies, intertidal and subtidal foraging, in a seasonal climate. Effects of both foraging strategy and seasonality on the daily energy expenditure (DEE) were measured using doubly labelled water. 2, Difference in foraging mode did not result in significant differences in DEE. 3, On Santa FC the DEE in the warm season was significantly higher than in the cool season (57.8 +/- 21.8 kJ kg(-0.8) day(-1) vs 38.0 kJ kg(-0.8) day(-1)). This difference can be explained by body temperature. A model estimate of the body temperature was used to predict monthly DEE figures, giving a year round budget. On average a l-kg iguana would need only 47 kJ day(-1), or 17 mJ year(-1). This is lower than previous estimates in which body temperatures were not taken into account. 4, The water flux of the Marine Iguana increases with increasing foraging time. The linear rise per minute foraging is roughly two times as high for subtidally foraging animals as for intertidal foragers. C1 Univ Groningen, Zool Lab, NL-9750 AA Haren, Netherlands. Univ Maastricht, NL-6200 MD Maastricht, Netherlands. Univ Illinois, Dept Ecol Ethol & Evolut, Champaign, IL 61820 USA. Smithsonian Trop Res Inst, Balboa, Panama. RP Drent, J (reprint author), Netherlands Inst Sea Res, POB 59, NL-1790 AB Den Burg, Netherlands. NR 30 TC 12 Z9 13 U1 2 U2 12 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0269-8463 J9 FUNCT ECOL JI Funct. Ecol. PD AUG PY 1999 VL 13 IS 4 BP 493 EP 499 DI 10.1046/j.1365-2435.1999.00337.x PG 7 WC Ecology SC Environmental Sciences & Ecology GA 241NK UT WOS:000082889300005 ER PT J AU Scharer, L Robertson, DR AF Scharer, L Robertson, DR TI Sperm and milt characteristics and male v. female gametic investment in the Caribbean reef fish, Thalassoma bifasciatum SO JOURNAL OF FISH BIOLOGY LA English DT Article DE sperm competition; sperm and milt characteristics; sperm; eggs; gemetic energy investment; coral reef fish ID SALMON SALMO-SALAR; TESTIS SIZE; ALTERNATIVE HYPOTHESES; SEXUAL SELECTION; BLUEHEAD WRASSE; COMPETITION; CONSEQUENCES; FERTILIZATION; STRATEGIES; EVOLUTION AB Individual sperm cells produced by two male morphs of the bluehead wrasse Thalassoma bifasciatum did not differ in size (i.e. cell volume). Initial phase (IP) males (high sperm competition) had a 60% higher sperm concentration in their milt than did terminal phase (TP) males (low sperm competition), which may reflect differences in how accurately the two male morphs need to allocate sperm to their spawns. The energy density of milt was about 16% lower than that of eggs. Estimates of gametic energy investment based on (a) the difference in testis weights between the beginning and the end of the spawning period and (b) the number of sperm released in natural spawns (determined in other studies), suggested that, on a daily basis, IP males invest about 65% of that of females. Estimates based on stripping milt from IP males at the beginning and the end of the spawning period, however, indicated that their daily energy investment in gamete production is about 10% of that of females. Gametic investment by TP males is lower than that by both IP males and females. (C) 1999 The Fisheries Society of the British Isles. C1 Univ Basel, Inst Zool, Lab Wirbeltierbiol, CH-4051 Basel, Switzerland. Smithsonian Trop Res Inst, APO, AA 34002 USA. RP Scharer, L (reprint author), Univ Bern, Inst Zool, Abt Verhaltensokol, CH-3032 Hinterkappelen, Switzerland. RI Scharer, Lukas/B-4396-2008 OI Scharer, Lukas/0000-0002-0209-9871 NR 35 TC 22 Z9 22 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD AUG PY 1999 VL 55 IS 2 BP 329 EP 343 DI 10.1006/jfbi.1999.0997 PG 15 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 219EJ UT WOS:000081594700008 ER PT J AU Ko, YK Gloeckler, G Cohen, CMS Galvin, AB AF Ko, YK Gloeckler, G Cohen, CMS Galvin, AB TI Solar wind ionic charge states during the Ulysses pole-to-pole pass SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY SPACE; IRON IONIZATION; CORONAL HOLE; PLASMA; LATITUDES; MODELS AB We analyze and compare the ionic charge composition data for different types of the solar wind (slow wind from equatorial regions, fast wind from low-latitude coronal hole and fast wind from both south and north polar coronal hole) which the Solar Wind Ion Composition Spectrometer (SWICS) on Ulysses observed during the pole-to-pole pass of its primary mission. The implications on the electron temperature, electron density, and ion outflow velocity from the corresponding solar wind source regions are also discussed. We find that the electron temperature in the source region of the slow solar wind is higher than that in the coronal hole. We also find a possible north-south asymmetry in the electron temperature that may be correlated to the north-south asymmetry in the solar wind speed found in the SWOOPS/Ulysses data. In particular, we make extensive discussions on the latitudinal variations in the polar coronal hole. On the basis of our data without clear constraints from other coronal observations, the preliminary result is that the electron density may be higher, or the heavy ion outflow velocities may be lower toward lower heliographic latitude. C1 Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. RP Ko, YK (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Galvin, Antoinette/A-6114-2013 NR 30 TC 21 Z9 21 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1999 VL 104 IS A8 BP 17005 EP 17019 DI 10.1029/1999JA900112 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 222NB UT WOS:000081790700003 ER PT J AU Hu, YQ Habbal, SR AF Hu, YQ Habbal, SR TI Resonant acceleration and heating of solar wind ions by dispersive ion cyclotron waves SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY ALFVENIC FLUCTUATIONS; HEAVY-IONS; RADIAL EVOLUTION; POWER SPECTRUM; CORONAL HOLES; TURBULENCE; ULYSSES; MODEL; CONSTRAINTS; TEMPERATURE AB We investigate the preferential acceleration and heating of solar wind alpha particles by the resonant cyclotron interaction with parallel-propagating left-hand-polarized ion cyclotron waves. The Alfven wave spectrum equation is generalized to multi-ion plasmas and a Kolmogorov type of cascade effect is introduced to transfer energy from the low-frequency Alfven waves to the high-frequency ion cyclotron waves, which are assumed to be entirely dissipated by the wave-particle interaction. In order to distribute the dissipated wave energy among the alphas and protons, the quasi-linear theory of the wave-particle interaction is used along with the cold plasma dispersion relation, and a power law spectrum of the ion cyclotron waves is assumed, with the spectral index as a free parameter of the model. The set of three-fluid solar wind equations and the Alfven wave spectrum equation are then solved in order to find fast solar wind solutions. It is found that the effect of the alpha particles on the dispersion relation, omitted in most previous wave-driven solar wind models, has a significant influence on the preferential acceleration and heating of the alphas, especially in the region close to the Sun. With this effect included, the alpha particles can be accelerated to a bulk flow speed faster than the protons by a few hundred kilometers per second and heated by the resonant cyclotron interaction to more than mass-proportional temperature values at several solar radii. However, this mechanism does not yield a differential speed of the order of an Alfven speed and a mass-proportional temperature for the alphas beyond 0.3 AU, as observed, which confirms the same conclusion reached previously by Isenberg and Hollweg [1983] for nondispersive ion cyclotron waves. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Sci & Technol China, Dept Earth & Space Sci, Hefei 230026, Anhui, Peoples R China. RP Hu, YQ (reprint author), Harvard Smithsonian Ctr Astrophys, MS-15, Cambridge, MA 02138 USA. NR 42 TC 79 Z9 82 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1999 VL 104 IS A8 BP 17045 EP 17056 DI 10.1029/1999JA900193 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 222NB UT WOS:000081790700006 ER PT J AU Ochoa-Acuna, H Francis, JM Oftedal, OT AF Ochoa-Acuna, H Francis, JM Oftedal, OT TI Influence of long intersuckling interval on composition of milk in the Juan Fernandez fur seal, Arctocephalus philippii SO JOURNAL OF MAMMALOGY LA English DT Article DE Arctocephalus philippii; Juan Fernandez fur seal; lactation; maternal strategies; pinnipeds; Chile ID GAZELLA; GROWTH; LIONS; PATTERNS AB Female Juan Fernandez fur seals, Arctocephalus philippii, undertake long foraging trips during lactation, resulting in intersuckling intervals that are among the longest ever recorded for a mammal. We collected 44 samples of milk from this fur seal to determine if milk would have a high concentration of fat, as predicted from the hypothesized relation between milk concentration and intersuckling interval. Milk of Juan Fernandez fur seals contained on average 55.1% dry matter, 41.4% fat, 11.9% protein, 1.2% sugar, 0.7% ash, 780 mg/kg calcium, and 840 mg/kg phosphorous. Content of fat and energy were the highest reported for a fur seal or sea lion (Family Otariidae) in the 1st month of lactation. Energetic content was 17.95 kJ/g, and 74% of fatty acids were unsaturated. Data from seven species and subspecies of otariid seals indicated that length of foraging trip explained 66% of the variation in content of fat in milk among taxa. Content of energy in milk of otariid seals also was explained primarily by the duration of trips to sea. C1 Univ Florida, Dept Zool, Gainesville, FL 32603 USA. Smithsonian Inst, Dept Zool Res, Natl Zool Pk, Washington, DC 20001 USA. RP Ochoa-Acuna, H (reprint author), Univ Florida, Dept Zool, Gainesville, FL 32603 USA. NR 49 TC 10 Z9 10 U1 0 U2 1 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 USA SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD AUG PY 1999 VL 80 IS 3 BP 758 EP 767 DI 10.2307/1383245 PG 10 WC Zoology SC Zoology GA 233UC UT WOS:000082444800006 ER PT J AU Chen, W McCarthy, MC Novick, SE Thaddeus, P AF Chen, W McCarthy, MC Novick, SE Thaddeus, P TI Microwave spectra of the methylpolyynes CH3(C equivalent to C)(6)H and CH3(C equivalent to C)(7)H SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article AB Two new methylpolyynes, CH3(C=C)(6)H (tridecahexayne) and CH3(C=C)(7)H (pentadecaheptayne), have been detected in a supersonic molecular beam by Fourier transform microwave spectroscopy. A total of 20 transitions of CH3(C=C)(6)H in the K = 0 and 1 rotational ladders and 8 transitions of CH3(C=C)(7)H in the K = 0 ladder were observed between 5 and 11 GHz, allowing for both molecules precise determination of rotational and centrifugal distortion constants. Like other long carbon chains of similar length, the rotational constants of the two new methylpolyynes are well predicted by extrapolation from the shorter members of the sequence; the addition of successive C-2 units evidently little perturbs the structure of the rest of the molecule. Centrifugal distortion is well described by the same semiclassical model that works well for the cyanopolyynes, one which treats a carbon chain as a thin elastic rod with a Young's modulus independent of length, (C) 1999 Academic Press. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Wesleyan Univ, Dept Chem, Middletown, CT 06459 USA. RP Chen, W (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI McCarthy, Michael/0000-0001-9142-0008 NR 14 TC 4 Z9 4 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD AUG PY 1999 VL 196 IS 2 BP 335 EP 337 DI 10.1006/jmsp.1999.7857 PG 3 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 220RH UT WOS:000081680900018 ER PT J AU Thollesson, M AF Thollesson, M TI Phylogenetic analysis of dorid nudibranchs (Gastropoda : Doridacea) using the mitochondrial 16S rRNA gene SO JOURNAL OF MOLLUSCAN STUDIES LA English DT Article ID MULTIPLE SEQUENCE ALIGNMENT; CEPAEA-NEMORALIS GASTROPODA; RIBOSOMAL DNA-SEQUENCES; EVOLUTIONARY TREES; MOLECULAR SYSTEMATICS; SITES; RNA; MOLLUSKS; WEIGHT; RATES AB A 400 bp region of the mitochondrial 16S rRNA gene was sequenced in 24 dorid nudibranch species. In addition a dendronotid nudibranch and a notaspidean were sequenced for use as outgroup. The sequences were characterized with respect to spatial variation and secondary structure. The data were analysed using parsimony, exploring the effects of alignment and weighting on the optimal hypothesis, and a distance analysis was also performed. The optimal hypotheses differed between the analyses, although the clades with substantial bootstrap proportions were usually present in all cases. These clades are in general congruent with existing classifications, and correspond to relationships within family level taxa. The relationships between these clades were inconclusive and the monophyletic status of higher taxa of particular interest (e.g., Eudoridoidea, Anadoridoidea) could neither be corroborated nor dismissed. C1 Univ Gothenburg, Dept Zool, SE-405 Gothenburg, Sweden. RP Thollesson, M (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. NR 68 TC 29 Z9 31 U1 0 U2 5 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0260-1230 J9 J MOLLUS STUD JI J. Molluscan Stud. PD AUG PY 1999 VL 65 BP 335 EP 353 DI 10.1093/mollus/65.3.335 PN 3 PG 19 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 235PV UT WOS:000082552500007 ER PT J AU Riley, SM AF Riley, SM TI The cigarette girl. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst, Lib, Washington, DC 20560 USA. RP Riley, SM (reprint author), Smithsonian Inst, Lib, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD AUG PY 1999 VL 124 IS 13 BP 143 EP 144 PG 2 WC Information Science & Library Science SC Information Science & Library Science GA 225NZ UT WOS:000081968800400 ER PT J AU Rogers, JS Swofford, DL AF Rogers, JS Swofford, DL TI Multiple local maxima for likelihoods of phylogenetic trees: A simulation study SO MOLECULAR BIOLOGY AND EVOLUTION LA English DT Article ID NUCLEOTIDE-SEQUENCES; CONSISTENCY; POINT; RATES AB Steel demonstrated that the maximum-likelihood function for a phylogenetic tree may have multiple local maxima. If this phenomenon were general, it would compromise the applicability of maximum likelihood as an optimality criterion for phylogenetic trees. In several simulation studies reported on in this paper, the true tree, and other trees of very high likelihood, rarely had multiple maxima. Our results thus provide reassurance that the value of maximum likelihood as a tree selection criterion is not compromised by the presence of multiple local maxima-the best estimates of the true tree are not likely to have them. This result holds true even when an incorrect nucleotide substitution model is used for tree selection. C1 Univ New Orleans, Dept Biol Sci, New Orleans, LA 70148 USA. Smithsonian Inst, Lab Mol Systemat, Washington, DC 20560 USA. RP Rogers, JS (reprint author), Univ New Orleans, Dept Biol Sci, New Orleans, LA 70148 USA. NR 12 TC 38 Z9 38 U1 0 U2 5 PU SOC MOLECULAR BIOLOGY EVOLUTION PI LAWRENCE PA PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0737-4038 J9 MOL BIOL EVOL JI Mol. Biol. Evol. PD AUG PY 1999 VL 16 IS 8 BP 1079 EP 1085 PG 7 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA 224XN UT WOS:000081925400008 PM 10507922 ER PT J AU Fogel, ML Tuross, N AF Fogel, ML Tuross, N TI Transformation of plant biochemicals to geological macromolecules during early diagenesis SO OECOLOGIA LA English DT Article; Proceedings Paper CT Conference on Applications of Stable Isotope Techniques to Ecological Studies CY APR 20-22, 1998 CL SASKATOON, CANADA SP Environm Canada, Canadian Wildlife Serv, Natl Water Res Inst, Saskatoon, Micromass, Europa Sci, Finnigan MAT DE stable isotopes; proteins; decomposition; diagenesis; marshes ID ISOTOPE FRACTIONATION; AMMONIUM UPTAKE; ORGANIC-CARBON; DECOMPOSITION; MARINE; PRESERVATION; NITROGEN; IDENTIFICATION; DELTA-C-13; SEDIMENTS AB Chemical and isotopic changes in plant biochemicals that were transformed into organic geochemicals have been measured in anaerobic, freshwater marsh environments. In two litter bag studies, plant biochemicals decayed extensively in the first year, as recorded by dry weight, C:N ratios, delta(15)N of bulk tissue and amino acids, and delta(13)C of individual amino acids. Molecular analyses of Rubisco revealed that the high-molecular-weight enzyme subunit could be recognized antigenically for at least 12 months, but concentrations and amounts declined. Geochemical compounds, advanced glycation endproducts, were not found in fresh plants, but formed gradually with first indications documented at 3 months. The organic remains of plants were reworked or replaced by microbial products from decomposition, as indicated by a shift in the isotopic composition of individual amino acids in total plant protein. In experiments with Rubisco, isotopic changes over time in the individual amino acids in the 50-60 kDa molecular weight range were substantial. These high-molecular-weight substances were no longer pristine molecules. Biochemical and isotopic tools for studying living processes have been demonstrated to be effective and novel approaches to identify and quantify altered geochemical remnants. C1 Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. Smithsonian Inst, Ctr Mat Res & Educ, Suitland, MD 20746 USA. RP Fogel, ML (reprint author), Carnegie Inst Washington, Geophys Lab, 5251 Broad Branch Rd NW, Washington, DC 20015 USA. RI Fogel, Marilyn/M-2395-2015 OI Fogel, Marilyn/0000-0002-1176-3818 NR 40 TC 71 Z9 73 U1 0 U2 16 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0029-8549 J9 OECOLOGIA JI Oecologia PD AUG PY 1999 VL 120 IS 3 BP 336 EP 346 DI 10.1007/s004420050867 PG 11 WC Ecology SC Environmental Sciences & Ecology GA 233PU UT WOS:000082435900004 PM 28308011 ER PT J AU Greenberg, R Pravosudov, V Sterling, J Kozlenko, A Kontorschikov, V AF Greenberg, R Pravosudov, V Sterling, J Kozlenko, A Kontorschikov, V TI Divergence in foraging behavior of foliage-gleaning birds of Canadian and Russian boreal forests SO OECOLOGIA LA English DT Article DE ecological convergence; Pleistocene glaciations; warblers; historical; outbreak insects ID GUILD STRUCTURE; COMMUNITIES; EVOLUTION; PATTERNS; DIVERSITY AB We compared foraging behavior of foliage-gleaning birds of the boreal forest of two Palaearctic (central Siberia and European Russia) and two Nearctic (Mackenzie and Ontario, Canada) sites. Using discriminant function analysis on paired sites we were able to distinguish foliage-gleaning species from the Nearctic and Palaearctic with few misclassifications. The two variables that most consistently distinguished species of the two avifaunas were the percentage use of conifer foliage and the percentage use of all foliage. Nearctic foliage-gleaner assemblages had more species that foraged predominantly from coniferous foliage and displayed a greater tendency to forage from foliage, both coniferous and broad-leafed, rather than twigs, branches, or other substrates. The greater specialization on foliage and, in particular, conifer foliage by New World canopy foliage insectivores is consistent with previously proposed hypotheses regarding the role of Pleistocene vegetation history on ecological generalization of Eurasian species. Boreal forest, composed primarily of spruce and pine, was widespread in eastern North America, whereas pockets of forest were scattered in Eurasia (mostly the mountains of southern Europe and Asia). This may have affected the populations of birds directly or indirectly through reduction in the diversity and abundance of defoliating outbreak insects. Loss of habitat and resources may have selected against ecological specialization on these habitats and resources. C1 Smithsonian Migratory Ctr, Natl Zool Pk, Washington, DC 20008 USA. Ohio State Univ, Dept Zool, Columbus, OH 43210 USA. RP Greenberg, R (reprint author), Smithsonian Migratory Ctr, Natl Zool Pk, Washington, DC 20008 USA. NR 59 TC 5 Z9 5 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0029-8549 J9 OECOLOGIA JI Oecologia PD AUG PY 1999 VL 120 IS 3 BP 451 EP 462 DI 10.1007/s004420050878 PG 12 WC Ecology SC Environmental Sciences & Ecology GA 233PU UT WOS:000082435900015 PM 28308022 ER PT J AU Reisenfeld, DB Gardner, LD Janzen, PH Savin, DW Kohl, JL AF Reisenfeld, DB Gardner, LD Janzen, PH Savin, DW Kohl, JL TI Absolute cross section for Si2+(3s(2) S-1 -> 3s3p P-1) electron-impact excitation SO PHYSICAL REVIEW A LA English DT Article ID 3S(2) S-1->3S3P P-3; III LINE RATIOS; SI-III; NEAR-THRESHOLD; DIELECTRONIC RECOMBINATION; RESONANCE STRUCTURE; EXPERIMENTAL APPARATUS; DETECTION EFFICIENCY; MICROCHANNEL PLATES; 2S-2P EXCITATION AB We have measured the absolute cross section for electron-impact excitation (EIE) of Si2+(3s(2 1)S --> 3s3p P-1) from energies below threshold to 11 eV above. A beams modulation technique with inclined electron and ion beams was used. Radiation at 120.7 nm from the excited ions was detected using an absolutely calibrated optical system. The fractional population of the Si2+(3s3p P-3 degrees) metastable state in the incident ion beam was determined to be 0.210 +/- 0.018 (1.65 sigma). The data have been corrected for contributions to the signal from radiative decay following excitation from the metastable state to 3s3p P-1 and 3p(2) P-3, and excitation from the ground stare to levels above the 3s3p Ip level. The experimental 0.56 +/- 0.08-eV energy spread allowed us to resolve complex resonance structure throughout the studied energy range. At the reported +/- 14% total experimental uncertainty level (1.65 sigma), the measured structure acid absolute scale of the cross section are in good agreement with 12-state close-coupling R-matrix calculations. [S1050-2947 (99)06008-4]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Reisenfeld, DB (reprint author), Univ Calif Los Alamos Natl Lab, M-S-D466, Los Alamos, NM 87545 USA. RI Savin, Daniel/B-9576-2012; Reisenfeld, Daniel/F-7614-2015 OI Savin, Daniel/0000-0002-1111-6610; NR 70 TC 10 Z9 11 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1999 VL 60 IS 2 BP 1153 EP 1164 DI 10.1103/PhysRevA.60.1153 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 227BU UT WOS:000082058900054 ER PT J AU Balakrishnan, N Esry, BD Sadeghpour, HR Cornett, ST Cavagnero, MJ AF Balakrishnan, N Esry, BD Sadeghpour, HR Cornett, ST Cavagnero, MJ TI Quantum wave-packet dynamics of the photodissociation of LiF SO PHYSICAL REVIEW A LA English DT Article ID INTENSE LASER-PULSES; REAL-TIME DYNAMICS; DISSOCIATION DYNAMICS; EVOLUTION; PREDISSOCIATION; EXCITATION; RESONANCE; STATES; MOTION; NAI AB A nuclear wave-packet description of the photodissociation of LiF is described, with emphasis on the dynamics associated with the formation of long-lived resonances. The predissociation is described using nb initio potential-energy curves and transition dipole matrix elements. The split operator method is used to propagate time-dependent coupled-channel wave functions in a diabatic representation. Dissociation is incorporated using absorbing potentials at large internuclear separations to prevent the return of flux from asymptotic regions. Extremely narrow resonances and broad window resonances are found atop a broad absorption envelope, in agreement with a recent stationary-state calculation. The lifetimes of the narrow resonances extend to hundreds of picoseconds, indicating the very slow nature of the dissociation dynamics. The features of the absorption spectrum are connected to specific aspects of the wave-packet motion on the ionic and covalent potential curves through a detailed study of the autocorrelation function. [S1050-2947(99)08108-1]. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. RP Balakrishnan, N (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. RI Esry, Brett/H-7511-2013 OI Esry, Brett/0000-0003-3207-8526 NR 27 TC 16 Z9 16 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1999 VL 60 IS 2 BP 1407 EP 1413 DI 10.1103/PhysRevA.60.1407 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 227BU UT WOS:000082058900082 ER PT J AU Esry, BD Greene, CH AF Esry, BD Greene, CH TI Validity of the shape-independent approximation for Bose-Einstein condensates SO PHYSICAL REVIEW A LA English DT Article ID ATOMS AB The validity of the shape-independent approximation is studied for three trapped atoms. By comparing the total ground-state energy calculated using pseudopotentials in the Hartree-Fock approximation to the exact ground-state energy, the shape-independent approximation is shown to agree quantitatively only in the low-density limit. It is also shown using configuration interaction that a Dirac delta function is not suitable as a replacement for the two-body interaction in exact theories. [S1050-2947(99)01208-1]. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. RP Esry, BD (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RI Greene, Chris/C-3821-2011; Esry, Brett/H-7511-2013 OI Greene, Chris/0000-0002-2096-6385; Esry, Brett/0000-0003-3207-8526 NR 31 TC 55 Z9 55 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1999 VL 60 IS 2 BP 1451 EP 1462 DI 10.1103/PhysRevA.60.1451 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 227BU UT WOS:000082058900087 ER PT J AU Correll, DL Jordan, TE Weller, DE AF Correll, DL Jordan, TE Weller, DE TI Transport of nitrogen and phosphorus from Rhode River watersheds during storm events SO WATER RESOURCES RESEARCH LA English DT Article ID CHESAPEAKE BAY; LAND-USE; NUTRIENT DYNAMICS; DISCHARGES; ESTUARY; EXPORT; FOREST; VARIABILITY; AGRICULTURE AB We studied storm discharges of nitrate and dissolved and particulate forms of ammonium, organic N, phosphate, and organic P from four adjacent small watersheds of differing land use on the Atlantic Coastal Plain in Maryland. We used V-notch weirs and automated storm samplers to measure discharges and collect samples at flow intervals during 76 storms. The watershed aquifers are perched on an impervious clay layer slightly above sea level, so that combined groundwater and surface water discharges were measured at the weirs. The concentrations of particulate forms of organic N (PON), organic P (POP), and inorganic P (PPi) increased up to 3 orders of magnitude during storm events and usually peaked prior to the peak water discharge, while concentrations of dissolved forms of organic N (DON), organic P (DOP), inorganic P (DPi), and nitrate did not change very much. Dissolved and particulate ammonium (DNH4 and PNH4, respectively) concentrations increased up to fivefold in storm events but remained low compared to other N forms, The watershed with the most cropland discharged the highest concentrations of total N, PON, DNH4, nitrate, POP, and PPi. A forested watershed discharged the highest concentrations of DON, PNH4, and DOP. The watershed with the most grazed land discharged the highest concentration of DPi. PON and POP were the dominant forms of N and P in storm discharges from all watersheds. Concentrations of nitrogen were higher in spring and summer storms than in winter storms, but phosphorus concentrations were much higher in the summer storms than in spring or winter. The concentrations of PPi, POP, PON, DNH4, and PNH4 increased significantly with peak water discharge among storms, while concentrations of DPi, DOP, DON, and nitrate were not correlated with peak discharge. The ratios of TN/TP and TIN/TIP declined significantly with peak water discharge among storms. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Correll, DL (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. OI Weller, Donald/0000-0002-7629-5437 NR 39 TC 46 Z9 47 U1 1 U2 29 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD AUG PY 1999 VL 35 IS 8 BP 2513 EP 2521 DI 10.1029/1999WR900058 PG 9 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 221FC UT WOS:000081712500020 ER PT J AU Ferraris, CJ Vari, RP AF Ferraris, CJ Vari, RP TI The South American catfish genus Auchenipterus Valenciennes, 1840 (Ostariophysi : Siluriformes : Auchenipteridae): monophyly and relationships, with a revisionary study SO ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Review DE Neotropical; Pisces; Teleostei; taxonomy; new species; neotype; lectotype; nomenclature ID FISH COMMUNITIES; FLOODPLAIN LAKES; FRENCH-GUIANA; RIVER; ARGENTINA; FORMOSA; BASIN AB The Neotropical catfishes of the genus Auchenipterus Valenciennes (1840) are reviewed, The genus is hypothesized to be a monophyletic assemblage on the basis of rile shared presence of grooves in the ventral surface of the head that accommodate adducted mental barbels. A possible second synapomorphy, the presence of papillae on the dorsal and medial surface of the ossified maxillary barbel of mature males: is tentatively advanced pending discovery of adult males of three species. Contrary to previous hypotheses which considered Auchenipterus to consist of a maximum of five species, we recognize 11 species, including two previously undescribed forms, A. britskii and A. menezesi: Auchenipterus is broadly distributed through the Rio Orinoco, Rio Amazonas, and Rio de La Plata basins, and the coastal drainages of the Guianas, with one species in the Rio Pindare-Mirim and Rio Parnaiba basins of northeastern Brazil. Auchenipterus nuchalis, previously thought to be broadly distributed across the range of the genus, is found to rather have a restricted distribution in the eastern portions of the Amazon basin, the lower portions of the Rio Tocantins, and lower courses of some rivers in Suriname and French Guiana. Citations of A. nuchalis from elsewhere: in the range of the genus are of other species. Euanemus Muller & Troschel (1842) and Ceratocheilus Miranda Ribeiro (1918) are considered synonyms of Auchenipterus. Euanemus colymbetes Muller & Troschel (1842) is considered a synonym of Auchenipterus dentatus Valenciennes (1840), and A. paysanduanus Devincenzi (1933) is placed into the synonyms of A. nigripinnis Boulenger (1895). A neotype is designated for Hypopthalmus nuchalis Spix & Agassiz (1829). Lectotypes are designated for Euanemus colymbetes and Auchenipterus nigripinnis. (C) 1999 The Linnean Society of London. C1 Calif Acad Sci, Dept Ichthyol, San Francisco, CA 94118 USA. Natl Museum Nat Hist, Dept Vertebrate Zool, Smithsonian Inst, Washington, DC 20560 USA. RP Ferraris, CJ (reprint author), Calif Acad Sci, Dept Ichthyol, Golden Gate Pk, San Francisco, CA 94118 USA. NR 113 TC 16 Z9 19 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0024-4082 J9 ZOOL J LINN SOC-LOND JI Zool. J. Linn. Soc. PD AUG PY 1999 VL 126 IS 4 BP 387 EP 450 DI 10.1111/j.1096-3642.1999.tb00156.x PG 64 WC Zoology SC Zoology GA 227YY UT WOS:000082108700001 ER PT J AU Stark, G Smith, PL Rufus, J Thorne, AP Pickering, JC Cox, G AF Stark, G Smith, PL Rufus, J Thorne, AP Pickering, JC Cox, G TI High-resolution photoabsorption cross-section measurements of SO2 at 295 K between 198 and 220 nm SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID HUBBLE-SPACE-TELESCOPE; STATE-SELECTIVE DETECTION; JET-COOLED SO2; SULFUR-DIOXIDE; IOS ATMOSPHERE; FLUORESCENCE SPECTROSCOPY; ASYMMETRIC STRUCTURE; VENUS; ULTRAVIOLET; BAND AB SO2 is an important constituent of the atmospheres of Io and Venus. Accurate photoabsorption cross-section data at the temperatures of these planetary atmospheres are required for the interpretation of SO2 observations and for reliable photochemical models. As part of a planned series of measurements over the 160-300 K range, photoabsorption cross sections of SO2 at 295 K, in the wavelength region 198-220 nm, have been determined from very high resolution (resolving power (lambda/Delta lambda) approximate to 450,000) absorption spectra recorded with a vacuum ultraviolet Fourier transform spectrometer. These new measurements are compared with earlier, lower-resolution (lambda/Delta lambda approximate to 100,000) photoabsorption measurements at 213 K spanning the same wavelength region, with lower-resolution (lambda/Delta lambda approximate to 100,000) measurements at 295 K in a more limited region, and with a recent Doppler-limited laser diode measurement at 295 K over a very narrow wavelength region. C1 Wellesley Coll, Dept Phys, Wellesley, MA 02481 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CURSOAR Technol, Watertown, MA USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. RP Stark, G (reprint author), Wellesley Coll, Dept Phys, 106 Cent St, Wellesley, MA 02481 USA. NR 44 TC 30 Z9 30 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD JUL 25 PY 1999 VL 104 IS E7 BP 16585 EP 16590 DI 10.1029/1999JE001022 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 218ZT UT WOS:000081583000010 ER PT J AU Wills, C Condit, R AF Wills, C Condit, R TI Similar non-random processes maintain diversity in two tropical rainforests SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE biodiversity; host-pathogen interactions; Janzen-Connell hypothesis ID SPECIES-DIVERSITY; RAIN-FOREST; TREE; DYNAMICS; HYPOTHESIS AB Quadrat-based analysis of two rainforest plots of area 50 ha, one in Panama (Barro Colorado Island, BCI) and the other in Malaysia (Pasoh), shows that in both plots recruitment is in general negatively correlated with both numbers and biomass of adult trees of the same species in the same quadrat. At BCI, this effect is not significantly influenced by treefall gaps. In both plots, recruitment of individual species is negatively correlated with the numbers of trees of all species in the quadrats, but not with overall biomass. These observations suggest, but do not prove, widespread frequency-dependent effects produced by pathogens and seed-predators that act most effectively in quadrats crowded with trees. Within-species correlations of mortality with numbers or biomass are not found in either plot, indicating that most frequency-dependent mortality takes place before the trees reach 1 cm in diameter. Stochastic effects caused by BCI's more rapid tree turnover may contribute to a larger variance in diversity from quadrat to quadrat at BCI, although they are not sufficient to explain why BCI has fewer than half as many tree species as Pasoh. Finally, in both plots quadrats with low diversity show a significant increase in diversity over time, and this increase is stronger at BCI. This process, like the frequency-dependence, will tend to maintain diversity over time. In general, these non-random forces that should lead to the maintenance of diversity are slightly stronger at BCI, even though the BCI plot is less diverse than the Pasoh plot. C1 Univ Calif San Diego, Dept Biol, La Jolla, CA 92093 USA. Univ Calif San Diego, Ctr Mol Genet, La Jolla, CA 92093 USA. Smithsonian Trop Res Inst, Balboa, Panama. RP Wills, C (reprint author), Univ Calif San Diego, Dept Biol, La Jolla, CA 92093 USA. EM cwills@ucsd.edu NR 25 TC 58 Z9 61 U1 1 U2 18 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD JUL 22 PY 1999 VL 266 IS 1427 BP 1445 EP 1452 PG 8 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA 223GU UT WOS:000081833200006 PM 10457617 ER PT J AU Torrelles, JM Gomez, JF Garay, G Rodriguez, LF Miranda, LF Curiel, S Ho, PTP AF Torrelles, JM Gomez, JF Garay, G Rodriguez, LF Miranda, LF Curiel, S Ho, PTP TI The distribution of the warm and dense molecular gas around Cepheus A HW 2 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : pre-main-sequence; ISM : individual : Cepheus A; ISM : jets and outflows; ISM : molecules; radio lines : ISM ID STAR-FORMING REGION; CLOUDS; BIPOLAR; OUTFLOW AB We present VLA observations of the (J, K) = (1, 1), (2, 2), (3, 3) and (4, 4) inversion transitions of NH3 toward the HW 2 object in Cepheus A, with 1-arcsec angular resolution. Emission is detected in the main hyperfine line of the first three transitions. The NH3(2, 2) emission shows a non-uniform 'ring' structure, which is more extended (3 arcsec) and intense than the emission seen in the (1, 1) and (3, 3) lines. A rotational temperature of similar to 30-50 K and a lower limit to the mass of similar to 1 (X-NH3/10(-8))(-1) M. are derived for the ring structure, The spatio-kinematical distribution of the NH3 emission does not seem to be consistent with a simple circumstellar disc around the HW 2 thermal biconical radio jet. We suggest that it represents the remnant of the parental core from which both the inner 300-au (0.4 arcsec) disc, traced by the water maser spots previously found in the region, and the central object have formed. The complex velocity field of this core is probably produced from bound motions (similar to those of the inner disc) and from interaction with outflowing material. C1 CSIC, IEEC, Edifici Nexus, E-08034 Barcelona, Spain. CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. INTA, Lab Astrofis Espacial & Fis Fundamental, E-28080 Madrid, Spain. Univ Chile, Dept Astron, Santiago, Chile. Univ Nacl Autonoma Mexico, Inst Astron, Mexico City 04510, DF, Mexico. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP CSIC, IEEC, Edifici Nexus, C Gran Capita 2-4, E-08034 Barcelona, Spain. RI Garay, Guido/H-8840-2013; Gomez, Jose Francisco/D-8392-2016; OI Garay, Guido/0000-0003-1649-7958; Gomez, Jose Francisco/0000-0002-7065-542X; Torrelles, Jose Maria/0000-0002-6896-6085 NR 22 TC 6 Z9 6 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUL 21 PY 1999 VL 307 IS 1 BP 58 EP 66 DI 10.1046/j.1365-8711.1999.02632.x PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 223AU UT WOS:000081818200008 ER PT J AU Uttley, P McHardy, IM Papadakis, IE Guainazzi, M Fruscione, A AF Uttley, P McHardy, IM Papadakis, IE Guainazzi, M Fruscione, A TI The swan song in context: long-time-scale X-ray variability of NGC 4051 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Letter DE galaxies : active; galaxies : individual : NGC 4051; galaxies : Seyfert; X-rays : galaxies ID SPECTRAL VARIABILITY; NGC-4051 AB On 1998 May 9-11, the highly variable, low-luminosity Seyfert I galaxy NGC 4051 was observed in an unusual low-flux state by BeppoSAX, RXTE and EUVE. We present fits of the 4-15 keV RXTE spectrum and BeppoSAX MECS spectrum obtained during this observation, which are consistent with the interpretation that the source had switched off, leaving only the spectrum of pure reflection from distant cold matter We place this result in context by showing the X-ray light curve of NGC 4051 obtained by our RXTE monitoring campaign over the past two and a half years, which shows that the low state lasted for similar to 150 d before the May observations (implying that the reflecting material is >10(17) cm from the continuum source) and forms part of a light curve showing distinct variations in long-term average flux over time-scales > months. We show that the long-time-scale component to X-ray variability is intrinsic to the primary continuum and is probably distinct from the variability at shorter time-scales. The long-time-scale component to variability maybe associated with variations in the accretion flow of matter on to the central black hole. As the source approaches the low state, the variability process becomes non-linear. NGC 4051 may represent a microcosm of all X-ray variability in radio-quiet active galactic nuclei (AGNs), displaying in a few years a variety of flux states and variability properties which more luminous AGNs may pass through on time-scales of decades to thousands of years. C1 Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. Univ Crete, Dept Phys, Heraklion 71003, Crete, Greece. European Space Agcy, Dept Space Sci, Div Astrophys, ESTEC, NL-2200 AG Noordwijk, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Uttley, P (reprint author), Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. RI Papadakis, Iossif/C-3235-2011 NR 15 TC 50 Z9 50 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUL 21 PY 1999 VL 307 IS 1 BP L6 EP L10 DI 10.1046/j.1365-8711.1999.02801.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 223AU UT WOS:000081818200002 ER PT J AU Croft, RAC Weinberg, DH Pettini, M Hernquist, L Katz, N AF Croft, RAC Weinberg, DH Pettini, M Hernquist, L Katz, N TI The power spectrum of mass fluctuations measured from the Ly alpha forest at redshift z=2.5 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; large-scale structure of universe; quasars : absorption lines ID COLD DARK-MATTER; PHOTOIONIZED INTERGALACTIC MEDIUM; COSMIC STRUCTURE FORMATION; LYMAN-BREAK GALAXIES; ABSORPTION-SPECTRUM; METAL ENRICHMENT; SCALE STRUCTURE; CLOUDS; DENSITY; EVOLUTION AB We measure the linear power spectrum of mass-density fluctuations at redshift z = 2.5 from the Ly alpha forest absorption in a sample of 19 QSO spectra, using the method introduced by Croft et al. The P(k) measurement covers the range 2 pi/k similar to 450-2350 km s(-1) (2-12 comoving h(-1) Mpc for Omega = 1), limited on the upper end by uncertainty in fitting the unabsorbed QSO continuum and on the lower end by finite spectral resolution (0.8-2.3 Angstrom FWHM) and by nonlinear dynamical effects. We examine a number of possible sources of systematic error and find none that are significant on these scales. In particular, we show that spatial variations in the UV background caused by the discreteness of the source population should have negligible effect on our P(k) measurement. We estimate statistical errors by dividing the data set into ten subsamples. The statistical uncertainty in the rms mass-fluctuation amplitude, a sigma proportional to [P(k)](1/2), is similar to 20%, and is dominated by the finite number of spectra in the sample. We obtain consistent P(k) measurements (with larger statistical uncertainties) from the high- and low-redshift halves of the data set, and from an entirely independent sample of nine QSO spectra with mean redshift z = 2.1. A power-law fit to our results yields a logarithmic slope n = -2.25 +/- 0.18 and an amplitude Delta(rho)(2)(k(p)) = 0.57(-0.18)(+0.26), where Delta(rho)(2) is the contribution to the density variance from a unit interval of ln k and k(p) = 0.008(km s(-1))(-1). Direct comparison of our mass P(k) to the measured clustering of Lyman break galaxies shows that they are a highly biased population, with a bias factor b similar to 2-5. The slope of the linear P(k), never previously measured on these scales, is close to that predicted by models based on inflation and cold dark matter (CDM). The P(k) amplitude is consistent with some scale-invariant, COBE-normalized CDM models (e.g., an open model with Omega(0) = 0.4) and inconsistent with others (e.g., Omega = 1). Even with limited dynamic range and substantial statistical uncertainty, a measurement of P(k) that has no unknown "bias factors" offers many opportunities for testing theories of structure formation and constraining cosmological parameters. C1 Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Royal Greenwich Observ, Cambridge CB3 0EZ, England. Univ Calif Santa Cruz, Lick Observ, Santa Cruz, CA 95064 USA. Univ Massachusetts, Dept Phys & Astron, Amherst, MA 01003 USA. RP Croft, RAC (reprint author), Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. RI Croft, Rupert/N-8707-2014 OI Croft, Rupert/0000-0003-0697-2583 NR 93 TC 161 Z9 163 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP 1 EP 23 DI 10.1086/307438 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RC UT WOS:000081395500001 ER PT J AU Churazov, E Gilfanov, H Forman, W Jones, C AF Churazov, E Gilfanov, H Forman, W Jones, C TI Evidence for merging in the Centaurus cluster SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (Centaurus); galaxies : interactions; X-rays : galaxies ID COOLING FLOWS; X-RAY; GALAXIES; GAS AB We present a two-dimensional map of the gas temperature distribution in the Centaurus cluster, based on Advanced Satellite for Cosmology and Astrophysics (ASCA) observations derived using a novel approach to account for the energy-dependent point-spread function. Along with a cool region centered on NGC 4696, asymmetric temperature variations of moderate amplitude are detected. The hottest region roughly coincides with the position of the second-brightest galaxy, NGC 4709, known to be the dominant galaxy of one of the subgroups in the Centaurus cluster. ROSAT images show faint surface brightness emission also centered on this galaxy. The imaging and spectral results suggest that a subcluster centered on NGC 4709 is merging with the main cluster centered on NGC 4696, in agreement with earlier suggestion that these two systems are located at the same distance, despite their different line-of-sight velocities. C1 Max Planck Inst Astrophys, D-85740 Munich, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Churazov, E (reprint author), Max Planck Inst Astrophys, Karl Schwarzschild Str 1, D-85740 Munich, Germany. RI Churazov, Eugene/A-7783-2013 NR 20 TC 47 Z9 47 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP 105 EP 110 DI 10.1086/307421 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RC UT WOS:000081395500011 ER PT J AU McCarthy, MC Chen, W Apponi, AJ Gottlieb, CA Thaddeus, P AF McCarthy, MC Chen, W Apponi, AJ Gottlieb, CA Thaddeus, P TI Hyperfine structure of the C5H, C6H, and C8H radicals SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : molecules; line : identification; molecular data; molecular processes; radio lines : ISM ID LABORATORY DETECTION; SPECTRUM; PARAMETERS; MOLECULES AB Hypefine structure in the rotational transitions of the C5H, C6H, and C8H carbon chain radicals has been measured with a Fourier transform microwave spectrometer. Enough transitions (four to six) between 7 and 22 GHz were measured for each radical to determine the hydrogen hyperfine coupling constants to high precision. The radio spectrum of each radical can now be calculated to better than 0.30 km s(-1) in equivalent radial velocity at frequencies less than 50 GHz, adequate for radio astronomical studies in very narrow line sources like TMC-1. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP McCarthy, MC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI McCarthy, Michael/0000-0001-9142-0008 NR 21 TC 29 Z9 29 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP 158 EP 161 DI 10.1086/307434 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RC UT WOS:000081395500017 ER PT J AU Quataert, E Gruzinov, A AF Quataert, E Gruzinov, A TI Turbulence and particle heating in advection-dominated accretion flows SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; MHD; plasmas; turbulence ID ALFVENIC TURBULENCE; NEUTRON-STARS; DISKS AB We extend and reconcile recent work on turbulence and particle heating in advection-dominated accretion hows. For approximately equipartition magnetic fields, the turbulence primarily heats the electrons. For weaker magnetic fields, the protons are primarily heated. The division between electron and proton heating occurs between beta similar to 5 and beta similar to 100 (beta is the ratio of gas to magnetic pressure), depending on unknown details of how Alfven waves are converted into whistlers on scales of the proton Larmor radius. We also discuss the possibility that magnetic reconnection could be a significant source of electron heating. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. RP Quataert, E (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 20 TC 121 Z9 122 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP 248 EP 255 DI 10.1086/307423 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RC UT WOS:000081395500027 ER PT J AU Psaltis, D Belloni, T van der Klis, M AF Psaltis, D Belloni, T van der Klis, M TI Correlations in quasi-periodic oscillation and noise frequencies among neutron star and black hole X-ray binaries SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; stars : neutron; stars : oscillations; X-rays : stars ID GX 339-4; CIRCINUS X-1; CYGNUS X-1; CIR X-1; DISCOVERY; CANDIDATE; VARIABILITY; BEHAVIOR; FLUX; GS-1124-683 AB We study systematically the similar or equal to 0.1-1200 Hz quasi-periodic oscillations (QPOs) and broad noise components observed in the power spectra of nonpulsing neutron star and black hole low-mass X-ray binaries. We show that among these components we can identify two, occurring over a wide range of source types and luminosities, whose frequencies follow a tight correlation. The variability components involved in this correlation include neutron star kilohertz QPOs and horizontal-branch oscillations, as well as black hole QPOs and noise components. Our results suggest that the same types of variability may occur in both neutron star and black hole systems over 3 orders of magnitude in frequency and with coherences that vary widely but systematically. Confirmation of this hypothesis will strongly constrain theoretical models of these phenomena and provide additional clues to understanding their nature. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Natl Inst Nucl & High Energy Phys, Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM dpsaltis@cfa.harvard.edu; tmb@astro.uva.nl; michiel@astro.uva.n1 NR 92 TC 239 Z9 242 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP 262 EP 270 DI 10.1086/307436 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RC UT WOS:000081395500029 ER PT J AU Menou, K Esin, AA Narayan, R Garcia, MR Lasota, JP McClintock, JE AF Menou, K Esin, AA Narayan, R Garcia, MR Lasota, JP McClintock, JE TI Black hole and neutron star transients in quiescence SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; black hole physics; stars : magnetic fields; stars : neutron; X-rays : stars ID ADVECTION-DOMINATED ACCRETION; X-RAY TRANSIENTS; CLOSE BINARY-SYSTEMS; CENTAURUS X-4; ORBITAL PERIOD; AQUILA X-1; MASS; MODEL; PULSAR; FLOWS AB We consider the X-ray luminosity difference between neutron star and black hole soft X-ray transients (NS and BH SXTs) in quiescence. The current observational data suggest that BH SXTs are significantly fainter than NS SXTs. The luminosities of quiescent BH SXTs are consistent with the predictions of binary-evolution models for the mass transfer rate if (1) accretion occurs via an advection-dominated accretion flow (ADAF) in these systems and (2) the accreting compact objects have event horizons. The luminosities of quiescent NS SXTs are not consistent with the predictions of ADAF models when combined with binary-evolution models, unless most of the mass accreted in the ADAF is prevented from reaching the neutron star surface. We consider the possibility that mass accretion is reduced in quiescent NS SXTs because of an efficient propeller and develop a model of the propeller effect that accounts for the observed luminosities. We argue that modest winds from ADAFs are consistent with the observations, while strong winds are probably not. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Observ Paris, Sect Meudon, Dept Astrophys Relativiste & Cosmol, CNRS,UPR 176, F-92195 Meudon, France. CALTECH, Pasadena, CA 91125 USA. RP Menou, K (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 93 TC 162 Z9 164 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP 276 EP 291 DI 10.1086/307443 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RC UT WOS:000081395500031 ER PT J AU Ko, YK Mukai, K Smale, AP White, NE AF Ko, YK Mukai, K Smale, AP White, NE TI ASCA observation of the dipping X-ray source XB 1916-053 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; stars : individual (XB 1916-053); X-rays : stars ID K LINE EMISSION; EXOSAT OBSERVATIONS; GINGA OBSERVATIONS; 4U 1915-05; BINARIES; ABSORPTION; DISCOVERY AB We present the results of timing and spectral studies of the dipping X-ray source XB 1916-053, observed by ASCA during its performance verification phase. The detected dipping activity is consistent with previous observations, with a period of 3008 s and an intermittent secondary dip observed roughly 0.4 out of phase with the primary dip. The energy spectra of different intensity states are fitted with a power law with partial covering fraction absorption and interstellar absorption. The increase in the hardness ratio during the primary and secondary dips, and the increase in the covering fraction and column density with decreasing X-ray intensity, all imply that the dipping is caused by the photoabsorbing materials that have been suggested to be where the accreted flow hits the outer edge of the disk materials. The spectra at all intensity levels show no apparent evidence for Fe or Ne emission lines. This may be due to the low metal abundance in the accretion flow. Alternatively, the X-ray luminosity of the central source may be too weak to excite emission lines, which are assumed to be produced by X-ray photoionization of the disk materials. C1 NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ko, YK (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 16 TC 3 Z9 3 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP 292 EP 297 DI 10.1086/307427 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RC UT WOS:000081395500032 ER PT J AU Quataert, E Narayan, R AF Quataert, E Narayan, R TI Spectral models of advection-dominated accretion flows with winds SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; Galaxy : center; galaxies : individual (NGC 4649); stars : individual (V404 Cygni) ID SAGITTARIUS-A-ASTERISK; X-RAY TRANSIENTS; BLACK-HOLE; GALACTIC-CENTER; OPTICALLY THIN; RADIO JETS; GALAXY; DISKS; LUMINOSITY; MILLIMETER AB We calculate spectral models of advection-dominated accretion flows, taking into account the possibility that significant mass may be lost to an outflow/wind We apply the models to the soft X-ray transient V404 Cyg in quiescence, the Galactic center source Sgr A*, and the nucleus of NGC 4649. We show that there are qualitative degeneracies between the mass-loss rate in the wind and parameters characterizing the microphysics of the accretion flow; of particular importance is delta, the fraction of the turbulent energy which heats the electrons. For small delta, current observations suggest that at most 90% of the mass originating at large radii is lost to a wind, so that at least similar to 10% reaches the central object. For large delta similar to 0.3, however, models with significantly more mass loss are in agreement with the observations. We conclude by highlighting future observations which may clarify the importance of mass loss in sub-Eddington accretion flows. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM equataert@cfa.harvard.edu; rnarayan@cfa.harvard.edu NR 65 TC 183 Z9 183 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP 298 EP 315 DI 10.1086/307439 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RC UT WOS:000081395500033 ER PT J AU Jayawardhana, R Hartmann, L Fazio, G Fisher, RS Telesco, CM Pina, RK AF Jayawardhana, R Hartmann, L Fazio, G Fisher, RS Telesco, CM Pina, RK TI Mid-infrared imaging of the young binary star Hen 3-600: Evidence for a dust disk around the primary SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : general; circumstellar matter; stars : formation; stars : pre-main-sequence ID T-TAURI STARS; MAIN-SEQUENCE STARS; FORMING REGIONS; MULTIPLICITY; OPHIUCHUS; SYSTEMS; SEARCH AB We present high-resolution mid-infrared observations of the nearby late-type young binary system Hen 3-600. The binary, at a distance of similar to 50 pc, could be a member of the TW Hydrae association, the nearest known group of young stars, with an age of a few million years. Our images make it possible for the first time to determine which star in the pair, separated by 1." 4, harbors the mid-infrared excess detected by IRAS. In the near-infrared, where the radiation is primarily photospheric, Hen 3-600A (M3) and Hen 3-600B (M3.5) have a flux ratio of 1.6. At 4.8, 10.8, and 18.2 mu m, the primary becomes increasingly dominant over the secondary, suggesting that most of the circumstellar dust in the system resides around Hen 3-600A. Comparison of the spectral energy distribution (SED) of Hen 3-600A to the median SED of classical T Tauri stars suggests that its disk may be truncated by the secondary and provides tentative evidence for a central disk hole. The distribution of dust in the Hen 3-600 system may provide important clues to the formation and evolution of protoplanetary disks in close binaries. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. RP Jayawardhana, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 41 TC 33 Z9 33 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP L41 EP L44 DI 10.1086/312148 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RD UT WOS:000081395600011 ER PT J AU Kaaret, P Piraino, S Bloser, PF Ford, EC Grindlay, JE Santangelo, A Smale, AP Zhang, W AF Kaaret, P Piraino, S Bloser, PF Ford, EC Grindlay, JE Santangelo, A Smale, AP Zhang, W TI Strong-field gravity and X-ray observations of 4U 1820-30 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; gravitation; relativity; stars : individual (4U 1820-30); stars : neutron; X-rays : stars ID QUASI-PERIODIC OSCILLATIONS; VARIABILITY; BINARIES; SPECTRA AB The behavior of quasi-periodic oscillations (QPOs) at frequencies near 1 kHz in the X-ray emission from the neutron star X-ray binary 4U 1820-30 has been interpreted as evidence for the existence of the marginally stable orbit, a key prediction of strong-field general relativity. The signature of the marginally stable orbit is a saturation in QPO frequency (assumed to track inner disk radius) versus mass accretion rate. Previous studies of 4U 1820-30 have used X-ray count rate as an indicator of mass accretion rate. However, X-ray count rate is known to not correlate robustly with mass accretion rate or QPO frequency in other sources. Here, we examine the QPO frequency dependence on two other indicators of mass accretion rate: energy flux and X-ray spectral shape. Using either of these indicators, we find that the QPO frequency saturates at high mass accretion rates. We interpret this as strong evidence for the existence of the marginally stable orbit. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CNR, IFCAI, I-90146 Palermo, Italy. Dipartimento Fis & Astron, I-90123 Palermo, Italy. Univ Amsterdam, Astron Inst Anton Pannekoek, Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kaaret, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 26 TC 42 Z9 42 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP L37 EP L40 DI 10.1086/312141 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RD UT WOS:000081395600010 ER PT J AU Mahdavi, A AF Mahdavi, A TI The cluster L-x-sigma relation has implications for scale-free cosmologies SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; galaxies : clusters : general; X-rays : galaxies ID SPHERICAL GALAXIES; RAY; MODEL AB I show that the cluster L-x-sigma relation should be sensitive to cosmologies with a scale-free power spectrum of initial density fluctuations, P(k) proportional to k(n). I derive the dependence and argue that a conservative interpretation of current observations implies n < -2.0 and n < -1.1 at the one-sided 90% and 99% confidence levels, respectively. This result, which agrees with constraints on n from the X-ray cluster temperature function, should be roughly independent of the value of Omega or Lambda. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Mahdavi, A (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP L17 EP L20 DI 10.1086/312140 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RD UT WOS:000081395600005 ER PT J AU Vikhlinin, A McNamara, BR Hornstrup, A Quintana, H Forman, W Jones, C Way, M AF Vikhlinin, A McNamara, BR Hornstrup, A Quintana, H Forman, W Jones, C Way, M TI X-ray overluminous elliptical galaxies: A new class of mass concentrations in the universe? SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; dark matter; galaxies : clusters : general; X-rays : galaxies ID LUMINOSITY FUNCTION; HOT PLASMA; CLUSTERS; GAS AB We detect four isolated, X-ray overluminous [L-x > 2 x 10(43) (h/0.5)(-2) ergs s(-1)] elliptical galaxies (OLEGs) in our 160 deg(2) ROSAT PSPC survey. The extent of their X-ray emission, total X-ray luminosity, total mass, and mass of the hot gas in these systems corresponds to poor clusters, and the optical luminosity of the central galaxies (M-R< -22.5 + 5 log h) is comparable to that of cluster cD galaxies. However, there are no detectable fainter galaxy concentrations around the central elliptical galaxy. The estimated mass-to-light ratio within the radius of detectable X-ray emission is in the range of 250-450 M./L., which is 2-3 times higher than typically found in clusters or groups. These objects can be the result of galaxy merging within a group. OLEGs must have been undisturbed for a very long time, which makes them the ultimate examples of systems in hydrostatic equilibrium. The number density of OLEGs is n = 2.4(-1.2)(+3.1) x 10(-7) (h/0.5)(-3) Mpc(-3) at the 90% confidence level. They comprise 20% of all clusters and groups of comparable X-ray luminosity, and nearly all field galaxies brighter than M-R = -22.5. The estimated contribution of OLEGs to the total mass density in the universe is close to that of T > 7 keV clusters. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Danish Space Res Inst, DK-2100 Copenhagen O, Denmark. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. RP Vikhlinin, A (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Way, Michael/D-5254-2012; OI Forman, William/0000-0002-9478-1682 NR 25 TC 98 Z9 98 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 1999 VL 520 IS 1 BP L1 EP L4 DI 10.1086/312134 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215RD UT WOS:000081395600001 ER PT J AU Fiore, F La Franca, F Giommi, P Elvis, M Matt, G Comastri, A Molendi, S Gioia, I AF Fiore, F La Franca, F Giommi, P Elvis, M Matt, G Comastri, A Molendi, S Gioia, I TI The contribution of faint active galactic nuclei to the hard X-ray background SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Letter DE surveys; galaxies : active; galaxies : general; X-rays : galaxies ID ROSAT SERENDIPITY SURVEY; LUMINOUS GALAXIES; ASCA OBSERVATIONS; LOCKMAN FIELD; DEEP SURVEY; TYPE-2 QSO; POPULATION; QUASARS; AGNS AB Hard X-ray selection is the most efficient way to discriminate between accretion-powered sources, such as active galactic nuclei (AGN), and sources dominated by starlight. Hard X-rays are also less affected than other bands by obscuration. We have therefore carried out the BeppoSAX High Energy Large Area Survey (HELLAS) in the largely unexplored 5-10 keV band, finding 180 sources in similar to 50 deg(2) of sky with flux greater than or similar to 5 x 10(-14) ergcm(-2)s(-1). After correction for the non-uniform sky coverage this corresponds to resolving about 30 per cent of the hard cosmic X-ray background (XRB). Here we report on a first optical spectroscopic identification campaign, finding 12 AGN out of 14 X-ray error boxes studied. Seven AGN show evidence for obscuration in X-ray and optical bands, a fraction higher than in previous ROSAT or ASCA-ROSAT surveys (at 95-99 and 90 per cent confidence levels respectively), thus supporting the scenario in which a significant fraction of the XRB is created by obscured AGN. C1 BeppoSAX Sci Data Ctr, I-00131 Rome, Italy. Osservatorio Astron Roma, I-00044 Monteporzio, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. Osservatorio Astron Bologna, I-40127 Bologna, Italy. CNR, IFCTR, I-20133 Milan, Italy. CNR, IRA, I-40129 Bologna, Italy. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. RP Fiore, F (reprint author), BeppoSAX Sci Data Ctr, Via Corcolle 19, I-00131 Rome, Italy. RI Gioia, Isabella/B-6982-2012; La Franca, Fabio/G-9631-2012; Comastri, Andrea/O-9543-2015 OI Gioia, Isabella/0000-0003-3127-498X; Comastri, Andrea/0000-0003-3451-9970 NR 47 TC 94 Z9 94 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUL 11 PY 1999 VL 306 IS 4 BP L55 EP L60 DI 10.1046/j.1365-8711.1999.02795.x PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 220UU UT WOS:000081686500003 ER PT J AU David, LP Forman, W Jones, C AF David, LP Forman, W Jones, C TI ROSAT PSPC observations of the richest (R >= 2) ACO clusters SO ASTROPHYSICAL JOURNAL LA English DT Article DE catalogs; galaxies : clusters : general; surveys; X-rays : galaxies ID X-RAY; ABELL CLUSTERS; UPPER LIMITS; CANDIDATE SUPERCLUSTERS; LUMINOSITY FUNCTIONS; GALAXY CLUSTERS; CATALOG; SAMPLE AB We have compiled an X-ray catalog of optically selected rich clusters of galaxies observed by the Position Sensitive Proportional Counter (PSPC) during the pointed GO phase of the ROSAT mission. This paper contains a systematic X-ray analysis of 150 clusters with an optical richness classification of R greater than or equal to 2 from the Abell, Corwin, & Olowin (ACO) catalog. All clusters were observed within 45' of the optical axis of the telescope during pointed PSPC observations. For each cluster, we calculate: the net 0.5-2.0 keV PSPC count rate (or 4 sigma upper limit) in a 1 Mpc radius aperture, 0.5-2.0 keV flux and luminosity, bolometric luminosity, and X-ray centroid. The cluster sample is then used to examine correlations between the X-ray and optical properties of clusters, derive the X-ray luminosity function of clusters with different optical classifications, and obtain a quantitative estimate of contamination (i.e., the fraction of clusters with an optical richness significantly overestimated due to interloping galaxies) in the ACO catalog. Because of the large held of view of the PSPC, many rich clusters were serendipitously observed during the GO phase of the ROSAT mission. Of the 150 clusters in our sample, 82 were observed serendipitously and 68 were targeted observations. The overall detection rate of serendipitously observed clusters is quite high at 76%. However, the detection rate is sensitive to the optical properties of clusters, and the details of the optical selection process. For example, all serendipitously observed Bautz-Morgan type I and type I-II clusters are detected, while only 71% of Bautz-Morgan type II, type II-III, and type III clusters are detected. Beyond z approximate to 0.1, 83% of the observed Abell clusters are detected, compared to only 60% of southern ACO clusters. Dire to the long integration times in pointed PSPC observations, the typical X-ray luminosity threshold for detection is quite low at similar to 10(43) ergs s(-1) for clusters within z = 0.2. This luminosity is more characteristic of an X-ray luminous group rather than a rich cluster. The nondetected clusters must therefore be either highly unrelaxed systems or have an optical richness that is significantly overestimated due to contamination by interloping galaxies. We show that the later possibility is more likely, since low X-ray luminosity clusters are preferentially found in denser cluster environments compared with X-ray luminous clusters. This contrast in cluster environment makes low X-ray luminosity clusters more susceptible to galaxy contamination than luminous systems. The fraction of clusters less luminous than an X-ray luminous group is thus a direct quantitative measure of contamination in the ACO catalog. We also find that the X-ray luminosity function of Abell clusters is not consistent with that of southern ACO clusters. Only by comparing R greater than or equal to 2 Abell clusters with R greater than or equal to 3 southern ACO clusters can we obtain consistency in their X-ray properties. This indicates that the optical richness of southern ACO clusters is overestimated by about 1 richness class. C1 Harvard Smithsonian Ctr Astrophys, Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP David, LP (reprint author), Harvard Smithsonian Ctr Astrophys, Smithsonian Astrophys Observ, 60 Garden St, Cambridge, MA 02138 USA. NR 35 TC 34 Z9 34 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 1999 VL 519 IS 2 BP 533 EP 548 DI 10.1086/307388 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 213XF UT WOS:000081298000010 ER PT J AU Gallagher, SC Brandt, WN Sambruna, RM Mathur, S Yamasaki, N AF Gallagher, SC Brandt, WN Sambruna, RM Mathur, S Yamasaki, N TI Exploratory ASCA observations of broad absorption line quasi-stellar objects SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; quasars : absorption lines; X-rays : galaxies ID OPTICALLY SELECTED QUASARS; GROUND-BASED OBSERVATIONS; X-RAY-ABSORPTION; COMPLETE SAMPLE; SPECTROGRAPH; ABUNDANCES; EMISSION AB We present the analysis and interpretation of a sample of eight ASCA observations of broad absorption line quasi-stellar objects (BALQSOs). This is the first moderate-sized sample of sensitive BALQSO observations above 2 keV, and the BALQSOs in our sample are among the optically brightest known (B = 14.5-18.5). Despite the ability of 2-10 keV X-rays to penetrate large column densities, we find BALQSOs to be extremely weak sources above 2 keV, and we are only able to add two new 2-10 keV detections (0226-104 and IRAS 07598 + 6508) to those previously reported. By comparison with non-BALQSOs of similar optical continuum magnitudes, we derive the column densities needed to suppress the expected X-ray fluxes of our BALQSOs. In several cases we derive column densities greater than or similar to 5 x 10(23) cm(-2) for a neutral absorber with solar abundances. These are the largest X-ray column densities yet cm inferred for BALQSOs, and they exceed ROSAT lower limits by about an order of magnitude. Optical brightness does not appear to be a good predictor of 2-10 keV brightness for BALQSOs, but our data do suggest that the BALQSOs with high optical continuum polarizations may be the X-ray-brighter members of the class. For example, the highly polarized object PHL 5200 appears to be unusually X-ray bright for a BALQSO given its optical magnitude. We discuss the implications of our results for future observations with AXAF and XMM. If the objects in our sample are representative of the BALQSO population, precision X-ray spectroscopy of most BALQSOs will unfortunately prove difficult in the near future. C1 Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Tokyo Metropolitan Univ, Dept Phys, Fac Sci, Tokyo 19203, Japan. RP Gallagher, SC (reprint author), Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA. RI Yamasaki, Noriko/C-2252-2008; Brandt, William/N-2844-2015 OI Brandt, William/0000-0002-0167-2453 NR 50 TC 93 Z9 94 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 1999 VL 519 IS 2 BP 549 EP 555 DI 10.1086/307405 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 213XF UT WOS:000081298000011 ER PT J AU Mathur, S Elvis, M Wilkes, B AF Mathur, S Elvis, M Wilkes, B TI Multiple velocity components in the CIV absorption line of NGC 5548 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 5548); galaxies : kinematics and dynamics galaxies : Seyfert; ultraviolet : galaxies ID ACTIVE GALACTIC NUCLEI; X-RAY; SEYFERT-GALAXY; NGC-5548; ULTRAVIOLET; REGION; ABSORBERS; NGC-4151; STEPS; SIZE AB We have observed the much-studied Seyfert 1 galaxy NGC 5548 with the Goddard High-Resolution Spectrograph (GHRS) on the Hubble Space Telescope (HST). Our 14 ks observation covers the C IV emission line at a resolution of greater than 20,000. Our purpose was to study the absorption line found at lower resolution by IUE and the HST Faint Object Spectrograph. We found that the C IV absorption line resolves into six separate doublets with equivalent widths of 0.07-0.38 Angstrom. The absorption lines have blueshifts relative to the systemic velocity of the galaxy of 380-1250 km s(-1), except for one, which has a redshift of 250 km s(-1), suggesting both inflow and outflow. The inflowing component may be related to the accretion flow into the nuclear black hole. All the doublet lines are resolved by the GHRS. Three doublets are narrow, with FWHM less than or similar to 100 km s(-1), and three are broad, FWHM similar to 160-290 km s(-1). We find evidence of partial covering by the narrow absorption lines. Either (but not both) of the two strongest broad doublets could be from the same material that produces the X-ray ionized absorber seen in soft X-rays. The remaining five systems must be at least 10 times less ionized (and so of lower total column density) to remain consistent with the X-ray spectra. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Mathur, S (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Wilkes, Belinda/0000-0003-1809-2364 NR 26 TC 40 Z9 40 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 1999 VL 519 IS 2 BP 605 EP 609 DI 10.1086/307416 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 213XF UT WOS:000081298000017 ER PT J AU Hasan, SS Kalkofen, W AF Hasan, SS Kalkofen, W TI Excitation of oscillations in photospheric flux tubes through buffeting by external granules SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : magnetic fields; Sun : oscillations ID NETWORK BRIGHT POINTS; LONGITUDINAL-TRANSVERSE WAVES; SPECTRAL-LINE RADIATION; SOLAR P-MODES; MAGNETIC-FIELDS; CHROMOSPHERIC OSCILLATIONS; QUIET SUN; PROPAGATION; ATMOSPHERE; CONVECTION AB We examine the excitation of transverse (kink) and longitudinal (sausage) waves in magnetic flux tubes by granules in the solar photosphere. The investigation is motivated by the interpretation of network oscillations in terms of flux tube wavers. We model the interaction between a granule, with a specified transverse velocity, and a vertical flux tube in terms of the Klein-Gordon equation, which we solve analytically as an initial value problem for both wave modes, assuming the same external impulse. The calculations show that for magnetic field strengths typical of the network, the energy flux in transverse waves is higher than in longitudinal waves by an order of magnitude, in agreement with the chromospheric power spectrum of network oscillations observed by Lites, Rutten, & Kalkofen. But for weaker fields, such as those that might be found in internetwork regions, the energy fluxes in the two modes are comparable. This result implies that if there are internetwork oscillations in magnetic flux tubes, they must show the cutoff periods of both longitudinal and transverse modes at 3 minutes and at 7 minutes or longer. We also find that granules with speeds of about 2 km s(-1) can efficiently excite transverse oscillations in frequent short-duration (typically 1 minute) bursts that can heat the corona. C1 Indian Inst Astrophys, Bangalore 560034, Karnataka, India. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Hasan, SS (reprint author), Indian Inst Astrophys, Bangalore 560034, Karnataka, India. EM hasan@iiap.ernet.in RI Hasan, Siraj/C-2927-2012 NR 60 TC 64 Z9 64 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 1999 VL 519 IS 2 BP 899 EP 910 DI 10.1086/307404 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 213XF UT WOS:000081298000045 ER PT J AU Taylor, JM Yan, ZC Dalgarno, A Babb, JF AF Taylor, JM Yan, ZC Dalgarno, A Babb, JF TI Variational calculations on the hydrogen molecular ion SO MOLECULAR PHYSICS LA English DT Article ID DIPOLE POLARIZABILITIES; STATES; H-2(+); H-2+; HD+; SPECTROSCOPY; D-2(+) AB We present high-precision non-relativistic variational calculations of bound vibrational-rotational state energies for the H-2(+) and D-2(+) molecular ions in each of the lowest electronic states of Sigma(g), Sigma(u), and Pi(u) symmetry. The calculations are carried out including coupling between Sigma and Pi states but without using the Born-Oppenheimer or any adiabatic approximation. Convergence studies are presented which indicate that the resulting energies for low-lying levels are accurate to about 10(-13). Our procedure accounts naturally for the lambda-doubling of the Pi(u) state. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Babb, JF (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. RI Taylor, Jacob/B-7826-2011; Yan, Zong-Chao/F-6668-2014; OI Taylor, Jacob/0000-0003-0493-5594; Babb, James/0000-0002-3883-9501 NR 40 TC 32 Z9 33 U1 0 U2 15 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD JUL 10 PY 1999 VL 97 IS 1-2 BP 25 EP 33 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 215PN UT WOS:000081390400004 ER PT J AU Currie, CR Mueller, UG Malloch, D AF Currie, CR Mueller, UG Malloch, D TI The agricultural pathology of ant fungus gardens SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID GROWING ANTS; NESTS; HYMENOPTERA; FORMICIDAE; ESCOVOPSIS; EVOLUTION; PARASITE AB Gardens of fungus-growing ants (Formicidae: Attini) traditionally have been thought to be free of microbial parasites with the fungal mutualist maintained in nearly pure "monocultures." We conducted extensive isolations of "alien" (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants. Contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites that are only known from attine gardens and that are found in most attine nests. These specialized garden parasites, belonging to the microfungus genus Escovopsis (Ascomycota: anamorphic Hypocreales), are horizontally transmitted between colonies. Consistent with theory of virulence evolution under this mode of pathogen transmission. Escovopsis is highly virulent and has the potential for rapid devastation of ant gardens, leading to colony mortality. The specialized parasite Escovopsis is more prevalent in gardens of the more derived ant lineages than in gardens of the more "primitive" (basal) ant lineages. Because fungal cultivars of derived attine lineages are asexual clones of apparently ancient origin whereas cultivars of primitive ant lineages were domesticated relatively recently from free-living sexual stocks, the increased virulence of pathogens associated with ancient asexual cultivars suggests an evolutionary cost to cultivar clonality, perhaps resulting from slower evolutionary rates of cultivars in the coevolutionary race with their pathogens. C1 Univ Toronto, Dept Bot, Toronto, ON M5S 3B2, Canada. Smithsonian Trop Res Inst, Balboa, Panama. Univ Maryland, Dept Biol, College Pk, MD 20742 USA. RP Currie, CR (reprint author), Univ Toronto, Dept Bot, 25 Willcocks St, Toronto, ON M5S 3B2, Canada. NR 35 TC 208 Z9 211 U1 3 U2 39 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUL 6 PY 1999 VL 96 IS 14 BP 7998 EP 8002 DI 10.1073/pnas.96.14.7998 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 214RV UT WOS:000081342100073 PM 10393936 ER PT J AU Roberts, TR AF Roberts, TR TI Fishes of the cyprinid genus Tor in the Nam Theun watershed (Mekong Basin) of Laos, with description of a new species SO RAFFLES BULLETIN OF ZOOLOGY LA English DT Article AB Three species of Tor are reported from the Nam Theun watershed in central Laos: Tor tambra, T. sinensis, and T. ater new species. They are distinguished by differences in scale counts, length of mental lobe, and coloration of body and fins (particularly the pelvic, anal and caudal fins). Adults and subadults of all three species have striking coloration, T, tambra predominantly yellowish-green, T. sinensis red, and T. ater black. In the Nam Theun and elsewhere in the Mekong basin, the juveniles of T. tambra are silvery with yellow or yellowish-orange fins, while juveniles of T. sinensis are silvery with red or pink fins. Juveniles of T. ater are unknown. T. tambra and T. sinensis have large scales, while T. ater has relatively small scales; T. tambra in the Nam Theun and T. ater have short mental lobes, T. sinensis a long mental lobe. Further study is needed to determine the identification of Tor species in the upper Mekong within the Yunnan Province of China, and in the lower Mekong of southern Laos and Cambodia. T. laterivirtatus, recently described from the Mekong basin in Yunnan, is identified as a synonym of T. sinensis. Systematics of Tor in the Malay Peninsula, Sumatra, Borneo and Java is confusing. All of the specimens have large scales. For the time bring, two species are recognised, T. tambra (with a short mental lobe) and T. tambroides (with a long mental Iobe), but there may actually be only a single species, highly variable in length of mental lobe and size at sexual maturity. Juveniles and adults sexually mature at small sizes (150-200 mm) an silvery with yellow, orange, pink or pale red fins irrespective of the length of the mental lobe. Coloration of large adults is poorly known (especially with regard to length of mental lobe). C1 Smithsonian Trop Res Inst, Balboa, Panama. RP Roberts, TR (reprint author), Capital Mans,1371 Phaholyotin Rd, Bangkok 10400, Thailand. NR 8 TC 16 Z9 19 U1 0 U2 2 PU NATL UNIV SINGAPORE, SCHOOL BIOLOGICAL SCIENCES PI SINGAPORE PA DEPT ZOOLOGY, KENT RIDGE, SINGAPORE 0511, SINGAPORE SN 0217-2445 J9 RAFFLES B ZOOL JI Raffles Bull. Zool. PD JUL 2 PY 1999 VL 47 IS 1 BP 225 EP 236 PG 12 WC Zoology SC Zoology GA 224QV UT WOS:000081910500014 ER PT J AU Carr, GD King, RM Powell, AM Robinson, H AF Carr, GD King, RM Powell, AM Robinson, H TI Chromosome numbers in Compositae. XVIII. SO AMERICAN JOURNAL OF BOTANY LA English DT Article DE Asteraceae; chromosome numbers; Compositae; cytotaxonomy; cytogenetics AB Chromosome numbers and other cytogenetic data were determined from microsporocytes in 316 collections including 13 tribes of Compositae, mostly from Africa, Australia, Mexico, Central America, and South America. First reports are provided for 66 species and the genera Cassinia (2n approximate to 14(II)), Feldstonia (2n = 14(II)). Gochnatia (2n approximate to 23(II)), and Pseudoconyza (n = 10). In addition, new chromosome numbers are established at the generic level in Acourtia, Calea, Craspedia, Gnaphalium, Helipterum, Liabum, Leucheria, Smallanthus, Trixis, and Viguiera and at the specific level in 13 additional species. C1 Univ Hawaii Manoa, Dept Bot, Honolulu, HI 96822 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. Sul Ross State Univ, Dept Biol, Alpine, TX 79832 USA. RP Carr, GD (reprint author), Univ Hawaii Manoa, Dept Bot, Honolulu, HI 96822 USA. NR 38 TC 46 Z9 53 U1 0 U2 0 PU BOTANICAL SOC AMER INC PI COLUMBUS PA OHIO STATE UNIV-DEPT BOTANY 1735 NEIL AVE, COLUMBUS, OH 43210 USA SN 0002-9122 J9 AM J BOT JI Am. J. Bot. PD JUL PY 1999 VL 86 IS 7 BP 1003 EP 1013 DI 10.2307/2656618 PG 11 WC Plant Sciences SC Plant Sciences GA 220DM UT WOS:000081649300012 PM 10406724 ER PT J AU Kaluzny, J Mochejska, BJ Stanek, KZ Krockenberger, M Sasselov, DD Tonry, JL Mateo, M AF Kaluzny, J Mochejska, BJ Stanek, KZ Krockenberger, M Sasselov, DD Tonry, JL Mateo, M TI Direct distances to nearby galaxies using detached eclipsing binaries and cepheids. IV. Variables in the field M31D SO ASTRONOMICAL JOURNAL LA English DT Article DE binaries : eclipsing; Cepheids; distance scale; galaxies : individual (M31); stars : variables : other ID SYSTEM; RADII AB We undertook a long-term project, DIRECT, to obtain the direct distances to two important galaxies in the cosmological distance ladder-M31 and M33-using detached eclipsing binaries (DEBs) and Cepheids. While rare and difficult to detect, DEBs provide us with the potential to determine these distances with an accuracy better than 5%. The extensive photometry obtained in order to detect DEBs provides us with good light curves for the Cepheid variables. These are essential to the parallel project to derive direct Baade-Wesselink distances to Cepheids in M31 and M33. For both Cepheids and eclipsing binaries, the distance estimates will be free of any intermediate steps. As a first step in the DIRECT project, between 1996 September and 1997 October we obtained 95 full/partial nights on the F. L. Whipple Observatory 1.2 m telescope and 36 full nights on the Michigan-Dartmouth-MIT 1.3 m telescope to search for DEBs and new Cepheids in the M31 and M33 galaxies. In this paper, the fourth in the series, we present the catalog of variable stars, most of them newly detected, found in the field M31D [(alpha, delta) = (11.degrees 03, 41.degrees 27), J2000.0]. We have found 71 variable stars: five eclipsing binaries, 38 Cepheids, and 28 other periodic, possible long-period or nonperiodic variables. The catalog of variables, as well as their photometry and finding charts, is available via anonymous ftp and the World Wide Web. The complete set of the CCD frames is available upon request. C1 Warsaw Univ Observ, PL-00478 Warsaw, Poland. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. RP Kaluzny, J (reprint author), Warsaw Univ Observ, Al Ujazdowskie 4, PL-00478 Warsaw, Poland. NR 28 TC 28 Z9 28 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUL PY 1999 VL 118 IS 1 BP 346 EP 365 DI 10.1086/300946 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 223WF UT WOS:000081864000022 ER PT J AU Hunter, TR Testi, L Zhang, Q Sridharan, TK AF Hunter, TR Testi, L Zhang, Q Sridharan, TK TI Molecular jets and H2O masers in the AFGL 5142 hot core SO ASTRONOMICAL JOURNAL LA English DT Article DE HII regions; ISM : individual (AFGL 5142); ISM : jets and outflows; radio continuum; radio emission lines; stars : formation ID ULTRACOMPACT HII-REGIONS; YOUNG STELLAR OBJECTS; FAR-INFRARED SOURCES; H-II REGIONS; MASSIVE STAR-FORMATION; LUMINOUS IRAS SOURCES; MULTIPOLAR OUTFLOW; FORMING REGION; METHYL CYANIDE; EMISSION AB We present centimeter and millimeter continuum and molecular line images of the massive star-forming region AFGL 5142. A compact (2 ".15) millimeter continuum core with integrated flux density of 125 mJy has been detected at 88 GHz. The emission peak coincides with a 1.5 mJy centimeter continuum source. A massive (similar to 35 M.) highly collimated north-south outflow emanating from the core is seen in both the HCO+ (1-0) and SiO (v = 0, J = 2-1) transitions. The millimeter continuum source coincides with a molecular core traced by the ambient velocity HCO+ (1-0), SiO (v = 0, J = 2-1), and (HCO+)-C-13 (1-0) emission. CH3CN (14-13) and (12-11) spectra indicate a gas temperature of approximately 65 K in the innermost core. While the millimeter continuum emission is probably mostly due to optically thin thermal emission from dust grains, the centimeter continuum source is consistent with an ionized wind. From the Lyman continuum flux required to sustain the ionized gas, we estimate that the exciting source should be a B2 or earlier zero-age main-sequence star. The 22 GHz H2O masers most closely associated with the central object have undergone substantial variability in flux and position during three epochs spread over eight years. In addition, two new water maser features have been detected significantly offset (3 "-4 ", 0.03 pc) from the centimeter continuum peak position. One of these maser features exhibits a linear structure of spots with spatial-kinematic evidence for a rotating circumstellar disk of radius 40 AU and dynamical mass of approximate to 1 M.. The other is found to be associated with a near-infrared source with large infrared excess. In addition to the 28 embedded stars previously seen in infrared images, we conclude that this cluster is concurrently forming both low- and high-mass stars. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Pasadena, CA 91125 USA. RP Hunter, TR (reprint author), Harvard Smithsonian Ctr Astrophys, MS-78,60 Garden St, Cambridge, MA 02138 USA. NR 54 TC 35 Z9 36 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUL PY 1999 VL 118 IS 1 BP 477 EP 487 DI 10.1086/300936 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 223WF UT WOS:000081864000033 ER PT J AU Garcia-Sanchez, J Preston, RA Jones, DL Weissman, PR Lestrade, JF Latham, DW Stefanik, RP AF Garcia-Sanchez, J Preston, RA Jones, DL Weissman, PR Lestrade, JF Latham, DW Stefanik, RP TI Stellar encounters with the Oort cloud based on Hipparcos data (vol 117, pg 1042, 1999) SO ASTRONOMICAL JOURNAL LA English DT Correction C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Observ Paris, Sect Meudon, Paris, France. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Garcia-Sanchez, J (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 1 TC 2 Z9 2 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUL PY 1999 VL 118 IS 1 BP 600 EP 600 DI 10.1086/300905 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 223WF UT WOS:000081864000044 ER PT J AU Ulmschneider, P Theurer, J Musielak, ZE Kurucz, R AF Ulmschneider, P Theurer, J Musielak, ZE Kurucz, R TI Acoustic wave energy fluxes for late-type stars - II. Nonsolar metallicities SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE convection; hydrodynamics; turbulence; waves; stars : chromospheres; stars : Hertzsprung-Russel (HR) and; C-M diagrams ID OPACITY TABLES; PROTOSTELLAR ENVELOPES; GENERATION; CONVECTION; EVOLUTION AB Using the Lighthill-Stein theory with modifications described by Musielak et al. (1994), the acoustic wave energy fluxes were computed for late-type stars with the solar metal abundance (population I stars) by Ulmschneider et al. (1996). We now extend these computations to stars with considerably lower metal content (population II stars with 1/10 to 1/1000 of solar metallicity) and find that the acoustic fluxes calculated for stars of different spectral types and different luminosities are affected differently by the metallicity. It is found that the Hertzsprung-Russel diagram can be subdivided into three domains (labeled I, II and III) representing a different dependence of the generated acoustic fluxes on the stellar metal abundance. For the high T-eff stars of domain I there is no dependence of the generated acoustic fluxes on metallicity. In domain III are stars with low T-eff. Here the generated acoustic fluxes are lowered roughly by an order of magnitude for every decrease of the metal content by an order of magnitude. Finally, domain II represents the transition between the other two domains and the generated acoustic fluxes strongly depend on T-eff. The boundaries between the domains I and II, and II and III can be defined by simple relationships between stellar effective temperatures and gravities. C1 Univ Heidelberg, Inst Theoret Astrophys, D-69121 Heidelberg, Germany. Univ Alabama, Ctr Space Plasma Aeron & Astrophys Res, Huntsville, AL 35899 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Ulmschneider, P (reprint author), Univ Heidelberg, Inst Theoret Astrophys, Tiergartenstr 15, D-69121 Heidelberg, Germany. EM ulmschneider@ita.uni-heidelberg.de NR 25 TC 22 Z9 22 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 1999 VL 347 IS 1 BP 243 EP 248 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219RJ UT WOS:000081620600030 ER PT J AU Moscadelli, L Menten, KM Walmsley, CM Reid, MJ AF Moscadelli, L Menten, KM Walmsley, CM Reid, MJ TI VLBA observations of 12 GHz methanol masers toward W3(OH) SO ASTROPHYSICAL JOURNAL LA English DT Article DE HII regions; ISM : individual (W3); ISM : molecules; masers; radio lines : ISM; stars : formation ID MAPS AB We have conducted VLBA observations of the 12 GHz CH3OH masers toward the ultracompact H II region W3(OH). The angular resolution of approximate to 1 mas is sufficient to resolve most of the maser spots and determine their sizes and brightness temperatures. The FWHM sizes of the spots are found from 12 to 10 AU with brightness temperatures between 10(9) and 6 x 10(11) K. The actual brightness temperatures may be higher (by a factor less than or equal to 10) than the measured values, because most of the spots have spectral profiles unresolved with our velocity resolution (0.28 km s(-1)). Our data also suggest the presence of a spatially extended component of maser emission with size 220 mas and brightness temperature less than or equal to 10(9) K. The comparison of our data with previous 6.7 GHz VLBI observations shows that there is a good spatial(less than or equal to 10 mas) and velocity (within 0.3 km s(-1)) correspondence between numerous 12 and 6.7 GHz CH3OH spots. Comparing our maps with those of Menten et al. yields relative proper motions of a few km s(-1) in magnitude. A "linear structure" of approximately 200 AU in size (P.A. = 141 degrees) is found in the northern methanol maser clump, which also shows a regular trend of radial velocities with projected positions (a velocity gradient of 2400 km s(-1) pc(-1)). C1 Max Planck Inst Radioastron, D-5300 Bonn 1, Germany. Osservatorio Astrofis Arcetri, I-50125 Florence, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Moscadelli, L (reprint author), Stn Astron Cagliari, Loc Poggio Pini,Str 54, I-09012 Capoterra, CA, Italy. OI Moscadelli, Luca/0000-0002-8517-8881 NR 20 TC 28 Z9 29 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 1999 VL 519 IS 1 BP 244 EP 256 DI 10.1086/307365 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211TH UT WOS:000081177600023 ER PT J AU Lee, CW Myers, PC AF Lee, CW Myers, PC TI A catalog of optically selected cores SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE catalogs; ISM : clouds; stars : pre-main-sequence ID MOLECULAR CLOUD CORES; OPHIUCHUS DARK CLOUD; DENSE CORES; STAR-FORMATION; CO SURVEY; IRAS SOURCES; MILKY-WAY; TAURUS; PROTOSTARS; (CO)-O-18 AB We present a new catalog of 406 dense cores optically selected by using the STScI Digitized Sky Survey (DSS). In this catalog 306 cores have neither an embedded young stellar object (EYSO) nor a pre-main-sequence (PMS) star, 94 cores have EYSOs (one core has both an EYSO and a PMS star), and six cores have PMS stars only. Our sample of dense cores in the catalog is fairly complete within a category of northern Lynds class 5 and 6 clouds and southern Hartley et al. class A clouds, providing a database useful for the systematic study of dense cores. Most of the cores listed in the catalog have diameters between 0.05 and 0.36 pc with a mean of similar to 0.24 pc. The sizes (similar to 0.33 pc in the mean) of cores with EYSOs are found to be usually larger than the sizes (similar to 0.22 pc in the mean) of starless cores. The typical mean gas density of the cores is similar to 7 x 10(3) cm(-3). Most of the cores are more likely elongated than spherical (mean aspect ratio: similar to 2.4). The ratio of the number of cores with EYSOs to the number of starless cores for our sample is about 0.3, suggesting that the typical lifetime of starless cores is 0.3-1.6 Myr, about 3 times longer than the duration of the class 0 and class I phases. This lifetime is shorter than expected from models of ambipolar diffusion, by factors of 2-44. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Lee, CW (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS 42, Cambridge, MA 02138 USA. NR 69 TC 168 Z9 168 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JUL PY 1999 VL 123 IS 1 BP 233 EP 250 DI 10.1086/313234 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219QN UT WOS:000081618400007 ER PT J AU Wildt, DE Wemmer, C AF Wildt, DE Wemmer, C TI Sex and wildlife: the role of reproductive science in conservation SO BIODIVERSITY AND CONSERVATION LA English DT Article DE artificial insemination; assisted breeding; endocrinology; genetic management; reproduction ID CERVUS-ELDI-THAMIN; MONITORING OVARIAN-FUNCTION; FROZEN-THAWED SPERMATOZOA; INTRAUTERINE INSEMINATION; ACINONYX-JUBATUS; FECAL STEROIDS; RESOURCE BANKS; URINARY; TESTOSTERONE; POPULATION AB This essay explains the role of reproductive science, including what are termed reproductive technologies (i.e. artificial insemination, in vitro fertilization, embryo transfer, cloning), in conservation biology. Reproductive techniques (high- and low-tech) find their greatest application in understanding species uniqueness, adaptations and physiological mechanisms, not in the large-scale assisted breeding and the production of offspring. Models of how to use these tools to study reproductive fitness are emerging to help insure gene diversity and even propagate endangered species, but only after fundamental databases have been developed. Examples are provided of how non-invasive hormone metabolite monitoring, artificial insemination and genome resource banking are being used ex situ and in situ to understand wildlife biology. We predict that as the fundamental, multi-species database grows, so will the applied benefits for: (1) developing genome banks for insuring extant genetic diversity; (2) assessing the relationship of physiology, behaviour and environmental perturbations; (3) managing small populations; and (4) dealing with dilemmas ranging from contraception to skewed sex ratios to animal welfare. Most progress will be made in using these tools in systematic studies to solve the mystery of how thousands of unstudied species reproduce. Carried out appropriately, financial costs will be consistent with any approach for generating sound scientific knowledge. C1 Smithsonian Inst, Conservat & Res Ctr, Natl Zool Pk, Front Royal, VA 22630 USA. RP Wildt, DE (reprint author), Smithsonian Inst, Conservat & Res Ctr, Natl Zool Pk, 1500 Remount Rd, Front Royal, VA 22630 USA. EM dewildt@shentel.net NR 50 TC 44 Z9 46 U1 6 U2 34 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0960-3115 EI 1572-9710 J9 BIODIVERS CONSERV JI Biodivers. Conserv. PD JUL PY 1999 VL 8 IS 7 BP 965 EP 976 DI 10.1023/A:1008813532763 PG 12 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 220QR UT WOS:000081678800005 ER PT J AU Pukazhenthi, B Pelican, K Wildt, D Howard, J AF Pukazhenthi, B Pelican, K Wildt, D Howard, J TI Sensitivity of domestic cat (Felis catus) sperm from normospermic versus teratospermic donors to cold-induced acrosomal damage SO BIOLOGY OF REPRODUCTION LA English DT Article ID FROZEN SPERMATOZOA; CAPACITATION; CRYOPRESERVATION; CHOLESTEROL; FERTILITY; SEMEN; FRESH AB Freeze-thawing cat sperm in cryoprotectant results in extensive membrane damage. To determine whether cooling alone influences sperm structure and viability, we compared the effect of cooling rate on sperm from normospermic (N; > 60% normal sperm per ejaculate) and teratospermic (T; < 40% normal sperm per ejaculate) domestic cats. Electroejaculates were divided into raw or washed (Ham's F-10 + 5% fetal calf serum) aliquots, with the latter resuspended in Ham's F-10 medium or Platz Diluent Variant Filtered without glycerol (20% egg yolk, 11% lactose). Aliquots were 1) maintained at 25 degrees C (no cooling; control), 2) cooled to 5 degrees C in a commercial refrigerator for 30 min (rapid cooling; similar to 4 degrees C/min), 3) placed in an ice slush at 0 degrees C for 10 min (ultrarapid cooling; similar to 14 degrees C/min), or 4) cooled to 0 degrees C at 0.5 degrees C/min in a programmable alcohol bath (slow cooling); and aliquots were removed every 4 degrees C. All samples then were warmed to 25 degrees C and evaluated for percentage sperm motility and the proportion of intact acrosomes using a fluorescein-conjugated peanut agglutinin stain. In both cat populations, sperm percentage motility remained unaffected (p > 0.05) immediately after exposure to low temperatures and after warming to 25 degrees C. However, the proportion of spermatozoa with intact acrosomes declined (p < 0.05) after rapid cooling (similar to 4 degrees C/min) to 5 degrees C (N, 65.6%; T, 27.5%) or ultrarapid cooling (similar to 14 degrees C/min) to 0 degrees C (N, 62.1%; T, 23.0%) in comparison to the control value (N, 81.5%; T, 77.5%). Transmission electron microscopy of cooled sperm revealed extensive damage to acrosomal membranes. In contrast, slow cooling (0.5 degrees C/min) to 5 degrees C maintained (p > 0.05) a high proportion of spermatozoa with intact acrosomes (N, 75.5%; T, 68.3%), which also remained similar (p > 0.05) between cat populations (N, 64.7%; T, 56.8%) through continued cooling to 0 degrees C. Results demonstrate that 1) rapid cooling of domestic cat sperm induces significant acrosomal damage without altering sperm motility, 2) spermatozoa from teratospermic males are more susceptible to cold-induced acrosomal damage than normospermic counterparts, and 3) reducing the rate of initial cooling markedly decreases sperm structural damage. C1 Smithsonian Inst, Natl Zool Pk, Conservat & Res Ctr, Front Royal, VA 22630 USA. RP Pukazhenthi, B (reprint author), Smithsonian Inst, Natl Zool Pk, Reprod Physiol Program, 3001 Connecticut Ave NW, Washington, DC 20008 USA. FU NCRR NIH HHS [KK01 RR00135] NR 38 TC 54 Z9 54 U1 0 U2 2 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 USA SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD JUL PY 1999 VL 61 IS 1 BP 135 EP 141 DI 10.1095/biolreprod61.1.135 PG 7 WC Reproductive Biology SC Reproductive Biology GA 211FP UT WOS:000081150200018 PM 10377041 ER PT J AU Spindler, RE Wildt, DE AF Spindler, RE Wildt, DE TI Circannual variations in intraovarian oocyte but not epididymal sperm quality in the domestic cat SO BIOLOGY OF REPRODUCTION LA English DT Article ID IN-VITRO; ZONA-PELLUCIDA; DEVELOPMENTAL COMPETENCE; FOLLICULAR OOCYTES; TERATOSPERMIC CATS; SIBERIAN TIGERS; HAMSTER OOCYTES; MATURED INVITRO; FERTILIZATION; SPERMATOZOA AB Ovaries and testes were collected throughout the year from domestic cats spayed and neutered at local veterinary clinics. Fresh oocytes recovered from minced ovaries were subjected to in vitro maturation and then stained to determine stage of maturation or were inseminated with conspecific sperm. The cauda and corpus regions of each epididymis were dissected into pieces and placed in medium; 30 min later, the epididymal tissue was removed, the medium centrifuged, and the sperm pellet resuspended. Samples were assessed for total sperm count and sperm motility traits, morphology, acrosomal integrity, and ability to penetrate cat oocytes in vitro. Fewer excellent (grade I) oocytes were recovered per ovarian pair during September-November (mean +/- SEM, 19.2 +/- 2.1%) than during January-July (36.8 +/- 3.6%, p < 0.05), while the remaining months had intermediate percentages of grade I oocytes (p > 0.05). A high percentage of oocytes recovered from November-April completed nuclear maturation (64.3 +/- 6.8%), which was different (p < 0.05) from the values for May-July (32.2 +/- 3.8%) and August-October (10.4 +/- 2.9%). Percentage of oocytes with bound sperm was lowest (p < 0.01) in September and October (32.0 +/- 3.1%) compared to February and March (91.4 +/- 1.7%). Percentage of oocytes with sperm within the perivitelline space was highest (p < 0.05) in May-August (33.8 +/- 4.6%) compared to all other months, In contrast, the period of highest (p < 0.01) fertilization (i.e., greater than or equal to 4-cell embryo formation) was March-April (51.7 +/- 3.1%) as compared to May-July (17.2 +/- 1.8%) or November-January (12.4 +/- 2.6%). Negligible numbers of oocytes recovered during August-October developed beyond the 2-cell stage (1.1 +/- 0.3%). Blastocyst development from cleaved embryos was highest during February-April (44.3 +/- 2.3%) and lowest during August-October (0.6 +/- 0.1%; p < 0.01). Sperm recovered from the epididymides throughout the year did not differ (p > 0.05) in concentration or in any of the motility, structural, or functional variables evaluated. In summary, cat oocyte nuclear maturation in vitro is depressed during August-October, and the ability to form cleaved embryos remains low even when the capacity to achieve nuclear maturation is relatively high (November-January and May-July). In contrast, male cats are capable of consistently producing viable, progressively motile sperm throughout the year. C1 Smithsonian Inst, Conservat & Res Ctr, Natl Zool Pk, Front Royal, VA 22630 USA. RP Spindler, RE (reprint author), Smithsonian Inst, Conservat & Res Ctr, Natl Zool Pk, 1500 Remount Rd, Front Royal, VA 22630 USA. EM rspindler@crc.si.edu NR 53 TC 73 Z9 75 U1 0 U2 8 PU SOC STUDY REPRODUCTION PI MADISON PA 1691 MONROE ST,SUITE # 3, MADISON, WI 53711-2021 USA SN 0006-3363 EI 1529-7268 J9 BIOL REPROD JI Biol. Reprod. PD JUL PY 1999 VL 61 IS 1 BP 188 EP 194 DI 10.1095/biolreprod61.1.188 PG 7 WC Reproductive Biology SC Reproductive Biology GA 211FP UT WOS:000081150200025 PM 10377048 ER PT J AU Pruski, JF AF Pruski, JF TI Gurania lobata (Cucurbitaceae), a new combination for an overlooked Linnaean name SO BRITTONIA LA English DT Article DE Cucurbitaceae; Anguria; Gurania; Psiguria; Linnaeus; suriname AB The new combination Gurania lobata (Cucurbitaceae) is made for Anguria lobata, an overlooked Linnaean name published in the original edition of Plantae Surinamenses, and G. spinulosa is treated as synonymous with this species. C1 US Natl Herbarium, Dept Bot, Smithsonian Inst, Washington, DC 20560 USA. RP Pruski, JF (reprint author), US Natl Herbarium, Dept Bot, Smithsonian Inst, MRC-166, Washington, DC 20560 USA. NR 25 TC 3 Z9 4 U1 1 U2 1 PU NEW YORK BOTANICAL GARDEN PI BRONX PA PUBLICATIONS DEPT, BRONX, NY 10458 USA SN 0007-196X J9 BRITTONIA JI Brittonia PD JUL-SEP PY 1999 VL 51 IS 3 BP 326 EP 330 DI 10.2307/2666612 PG 5 WC Plant Sciences SC Plant Sciences GA 233YT UT WOS:000082455300005 ER PT J AU Rho, BJ Cole, L AF Rho, BJ Cole, L TI Metandrocarpa kudoi, a new colonial ascidian (Stolidobranchia, Styelidae) from Korea SO BULLETIN OF MARINE SCIENCE LA English DT Article AB A new species of Metandrocarpa (Stolidobranchia: Styelidae) is described from Kudo (Koje Islands). One colony was attached to rock and another was associated with the tunicate Styela clava. The zooids of this new species are flattened laterally and not dorsoventrally. This species has 7-8 internal longitudinal branchial vessels on each side, 10-20 oral tentacles of 5-6 different sizes, 14-15 rows of branchial stigmata, and a short rounded plicated stomach with a curved caecum. On the right side, the gonads lie in a row along the endostyle with the ovaries anterior to the testes; on the left side, the ovaries lie along the endostyle with the testes running alongside the intestinal loop. C1 Ewha Womans Univ, Dept Biol Sci, Seoul 120750, South Korea. Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Rho, BJ (reprint author), Ewha Womans Univ, Dept Biol Sci, Seoul 120750, South Korea. NR 19 TC 0 Z9 1 U1 0 U2 0 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 EI 1553-6955 J9 B MAR SCI JI Bull. Mar. Sci. PD JUL PY 1999 VL 65 IS 1 BP 151 EP 157 PG 7 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 216BJ UT WOS:000081420400010 ER PT J AU Hendler, G Baldwin, CC Smith, DG Thacker, CE AF Hendler, G Baldwin, CC Smith, DG Thacker, CE TI Planktonic dispersal of juvenile brittle stars (Echinodermata : Ophiuroidea) on a Caribbean reef SO BULLETIN OF MARINE SCIENCE LA English DT Article ID INVERTEBRATES; METAMORPHOSIS; BIOGEOGRAPHY; GASTROPODS; MOLLUSKS; BIVALVES; ECOLOGY; LARVAE; FAUNA AB Juveniles of four species of shallow water ophiuroids were captured in a plankton net tethered on the reef flat at Carrie Bow Gay, Belize: Ophiothrix orstedii, Ophiothrix angulata, Ophiocoma wendtii, and Ophiactis savignyi. These water-borne animals were similar in size to the smallest benthic conspecifics found on the reef, but considerably larger than newly metamorphosed postlarvae. Thus, this first report of planktonic dispersal by juvenile coral reef ophiuroids suggests that they reenter the plankton and drift, or perhaps raft on algal fragments, after first having recruited to the benthos. The occurrence of water-borne juveniles in species with planktotrophic and abbreviated larval development, and with clonal, asexual reproduction suggests that postlarval drifting may augment larval dispersal in some ophiuroid species and substitute for it in others. C1 Nat Hist Museum Los Angeles Cty, Los Angeles, CA 90007 USA. Smithsonian Inst, Museum Natl Hist Nat, Div Fishes, Washington, DC 20560 USA. Univ Michigan, Museum Zool, Fish Div, Ann Arbor, MI 48109 USA. RP Hendler, G (reprint author), Nat Hist Museum Los Angeles Cty, 900 Exposit Blvd, Los Angeles, CA 90007 USA. EM hendler@nhm.org NR 33 TC 8 Z9 10 U1 0 U2 4 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 EI 1553-6955 J9 B MAR SCI JI Bull. Mar. Sci. PD JUL PY 1999 VL 65 IS 1 BP 283 EP 288 PG 6 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 216BJ UT WOS:000081420400020 ER PT J AU Pandolfi, JM Llewellyn, G Jackson, JBC AF Pandolfi, JM Llewellyn, G Jackson, JBC TI Pleistocene reef environments, constituent grains, and coral community structure: Curacao, Netherlands Antilles SO CORAL REEFS LA English DT Article DE reef corals; coral reefs; constituent grain analysis; paleoecology; quaternary; community ecology ID MONTASTRAEA-ANNULARIS; HUON-PENINSULA; FRINGING-REEF; BARRIER-REEF; NEW-GUINEA; FACIES; GROWTH; ASSEMBLAGES AB We investigated the degree to which component grains vary with depositional environment in sediments from three reef habitats from the Pleistocene (125 ka) Hate Unit of the Lower Terrace, Curacao, Netherlands Antilles: windward reef crest, windward back reef, and leeward reef crest. The windward reef crest sediment is the most distinctive, dominated by fragments of encrusting and branching coralline red algae, coral fragments and the encrusting foraminiferan Carpenteria sp. Windward back reef and leeward reef crest sediments are more similar compositionally, only showing significant differences in relative abundance of coral fragments and Homotrema rubrum. Although lacking high taxonomic resolution and subject to modification by transport, relative abundance of constituent grain types offers a way of assessing ancient skeletal reef community composition, and one which is not limited to a single taxonomic group. The strong correlation between grain type and environment we found in the Pleistocene of Curacao suggests that constituent grain analysis may be an effective tool in delineating Pleistocene Caribbean reef environments. However, it will not be a sufficient indicator where communities vary significantly within reef environments or where evolutionary and/or biogeographical processes lead to different relationships between community composition and reef environment. Detailed interpretation of geological, biological, and physical characteristics of the Pleistocene reefs of Curacao reveals that the abundance of the single coral species, Acropora palmata, is not a good predictor of the ecological structure of the ancient reef coral communities. This coral was the predominant species in two of the three reef habitats (windward and leeward reef crest), but the taxonomic composition (based on species relative abundance data) of the reef coral communities was substantially different in these two environments. We conclude that qualitative estimates of coral distribution patterns (presence of a key coral species or the use of a distinctive coral skeletal architecture), when used as a component in a multi-component analysis of ancient reef environments, probably introduces minimal circular reasoning into quantitative paleoecological studies of reef coral community structure. C1 Smithsonian Inst, Natl Museum Amer Hist, Dept Paleobiol, Washington, DC 20560 USA. Univ Diponegoro, McMaster UNDIP Project, Semarang, Central Java, India. Smithsonian Trop Res Inst, Ctr Trop Paleoecol & Archaeol, Balboa, Panama. RP Pandolfi, JM (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Dept Paleobiol, Washington, DC 20560 USA. RI Pandolfi, John/A-3121-2009 OI Pandolfi, John/0000-0003-3047-6694 NR 62 TC 25 Z9 26 U1 4 U2 12 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD JUL PY 1999 VL 18 IS 2 BP 107 EP 122 DI 10.1007/s003380050165 PG 16 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 223PT UT WOS:000081850000003 ER PT J AU Littler, MM Littler, DS AF Littler, MM Littler, DS TI Disturbances due to Cyclone Gavin parallel those caused by a ship grounding SO CORAL REEFS LA English DT Article C1 Smithsonian Inst, Natl Museum Amer Hist, Dept Bot, Washington, DC 20560 USA. Harbor Branch Oceanog Inst Inc, Div Marine Sci, Ft Pierce, FL 34946 USA. RP Littler, MM (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Dept Bot, Washington, DC 20560 USA. NR 1 TC 5 Z9 6 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD JUL PY 1999 VL 18 IS 2 BP 146 EP 146 DI 10.1007/s003380050169 PG 1 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 223PT UT WOS:000081850000007 ER PT J AU Littler, MM Littler, DS AF Littler, MM Littler, DS TI Castles built by a chiton from the Great Astrolabe Reef, Fiji SO CORAL REEFS LA English DT Article C1 Smithsonian Inst, Natl Museum Amer Hist, Dept Bot, Washington, DC 20560 USA. Harbor Branch Oceanog Inst Inc, Div Marine Sci, Ft Pierce, FL 34946 USA. RP Littler, MM (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Dept Bot, Washington, DC 20560 USA. NR 2 TC 5 Z9 5 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD JUL PY 1999 VL 18 IS 2 BP 158 EP 158 DI 10.1007/s003380050171 PG 1 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 223PT UT WOS:000081850000009 ER PT J AU Poe, P Norenburg, JL AF Poe, P Norenburg, JL TI Observations on depth distribution, diversity and abundance of pelagic nemerteans from the Pacific Ocean off California and Hawaii SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article DE nemerteans; pelagic; abundances; depth distribution; diversity AB Meso- and bathypelagic nemerteans were collected during five cruises west of Pt. Conception, California, and one west of Oahu, Hawaii, from depths of 0-3800 m, using a 10 m(2) Tucker Trawl modified with a thermally protected closing cod end, as well as MOCNESS-10 and MOCNESS-1D trawls. In this study, about 53 putative species were collected off California and about 23 off Hawaii, with little taxonomic overlap between the two groups, as compared to 16 and 0 species previously known from these regions. Numbers of nemertean individuals and species were greatest between 625 and 1750 m off California, and 1300-2500 m off Hawaii. Abundance of nemerteans off California was about 10 times that off Hawaii. The Shannon-Wiener diversity index (H') was higher for Hawaii than for California due to numerical dominance by two species, Phallonemertes cf murrayi and Nectonemertes cf mirabilis, off California and a more even species distribution off Hawaii. Neither of the two dominant California species showed evidence of nocturnal vertical migration to shallow water. This is the first report of a Phallonemertes species from the Pacific and the first report of pelagic nemerteans from waters off Hawaii. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Calif State Univ Stanislaus, Dept Biol Sci, Turlock, CA 95382 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Poe, P (reprint author), Calif State Univ Stanislaus, Dept Biol Sci, Turlock, CA 95382 USA. RI Norenburg, Jon/K-3481-2015 OI Norenburg, Jon/0000-0001-7776-1527 NR 25 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD JUL PY 1999 VL 46 IS 7 BP 1201 EP 1220 PG 20 WC Oceanography SC Oceanography GA 204WE UT WOS:000080787000005 ER PT J AU Sierra, R Rodriguez, F Loses, E AF Sierra, R Rodriguez, F Loses, E TI Forest resource use change during early market integration in tropical rain forests: the Huaorani of upper Amazonia SO ECOLOGICAL ECONOMICS LA English DT Article DE subsistence commodities; commercial commodities; tropical rain forest; markets; trade ID SUBSISTENCE; INDIANS; INTENSIFICATION; SUSTAINABILITY; AGRICULTURE; HUNTERS; FOOD AB This paper examines the impact of early market integration on the extraction of forest resources by traditional forest-based households, with emphasis on the commercial-subsistence dichotomy. Empirical analysis of resource use transition among the Huaorani People of the Ecuadorian Amazon shows that as markets become more accessible production patterns change but do not seem to affect subsistence production. Huaoranis increase the production of animal resources from forests. However, the extraction of harvested and primarily of farmed commodities seems not to be affected. Data also suggest that trade relies on limited specialization. Trade among the Huaorani communities studied depends on raising the production of some of the same commodities that are found in the subsistence basket. These changes are clearly explained if a flexible-labor theory of early market integration is used. This period is characterized by labor and land abundance and a relative ease to move labor from low return to more productive activities. Under these conditions, market participation need not be accompanied by a reduction in the production of subsistence commodities or commodity specialization. High risks and uncertainty and high transportation costs keep poor forest households from shifting completely to commercial activities. This contrasts with a long presumption that production of individual commodities responds quickly to price changes, based on demand shifts between products, but that total output is slow to respond. Only after all the surplus labor has been allocated to productive activities total output becomes less flexible. At this point increased production requires commodity or technological specialization. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Arizona State Univ, Dept Geog, Tempe, AZ 85287 USA. EcoCiencia, Quito, Ecuador. Smithsonian Inst, Ctr Trop Forest Sci, Washington, DC 20560 USA. RP Sierra, R (reprint author), Arizona State Univ, Dept Geog, 338 JWS, Tempe, AZ 85287 USA. NR 41 TC 22 Z9 22 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8009 J9 ECOL ECON JI Ecol. Econ. PD JUL PY 1999 VL 30 IS 1 BP 107 EP 119 DI 10.1016/S0921-8009(98)00101-3 PG 13 WC Ecology; Economics; Environmental Sciences; Environmental Studies SC Environmental Sciences & Ecology; Business & Economics GA 221RN UT WOS:000081740200010 ER PT J AU Clark, JS Silman, M Kern, R Macklin, E HilleRisLambers, J AF Clark, JS Silman, M Kern, R Macklin, E HilleRisLambers, J TI Seed dispersal near and far: Patterns across temperate and tropical forests SO ECOLOGY LA English DT Article DE Bayesian analysis; dispersal kernel; exponential model; forest dynamics; gamma; Gaussian model; migration; seed dispersal; seed shadow; Student's t ID WIND DISPERSAL; RECRUITMENT LIMITATION; PLANT MIGRATION; CLIMATE-CHANGE; MODELS; SPREAD; TREE; CONSEQUENCES; ENVIRONMENTS; KURTOSIS AB Dispersal affects community dynamics and vegetation response to global change. Understanding these effects requires descriptions of dispersal at local and regional scales and statistical models that permit estimation. Classical models of dispersal describe local or long-distance dispersal, but not both. The lack of statistical methods means that models have rarely been fitted to seed dispersal in closed forests. We present a mixture model of dispersal that assumes a range of disperal patterns, both local and long distance. The bivariate Student's t or "2Dt" follows from an assumption that the distance parameter in a Gaussian model varies randomly, thus having a density of its own. We use an inverse approach to "compete" our mixture model against classical alternatives, using seed rain databases from temperate broadleaf, temperate mixed-conifer, and tropical floodplain forests. For most species, the 2Dt model fits dispersal data better than do classical models, The superior fit results from the potential for a convex shape near the source tree and a "fat tail." Our parameter estimates have implications for community dynamics at local scales, for vegetation responses to global change at regional scales, and for differences in seed dispersal among biomes. The 2Dt model predicts that less seed travels beyond the immediate crown influence (<5 m) than is predicted under a Gaussian model, but that more seed travels longer distances (>30 m). Although Gaussian and exponential models predict slow population spread in the face of environmental change, our dispersal estimates suggest rapid spread. The preponderance of animal-dispersed and rare seed types in tropical forests results in noisier patterns of dispersal than occur in temperate hardwood and conifer stands. C1 Duke Univ, Dept Bot, Durham, NC 27708 USA. Harvard Univ, Dept Organism & Evolutionary Biol, Cambridge, MA 02138 USA. Harvard Univ, Harvard Forest, Petersham, MA 01366 USA. Smithsonian Trop Res Inst, Miami, FL 34002 USA. RP Clark, JS (reprint author), Duke Univ, Dept Bot, Durham, NC 27708 USA. RI Clark, James/G-6331-2011; Silman, Miles/H-1280-2011; Macklin, Eric/E-2955-2013 OI Macklin, Eric/0000-0003-1618-3502 NR 58 TC 492 Z9 520 U1 15 U2 162 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 0012-9658 J9 ECOLOGY JI Ecology PD JUL PY 1999 VL 80 IS 5 BP 1475 EP 1494 DI 10.1890/0012-9658(1999)080[1475:SDNAFP]2.0.CO;2 PG 20 WC Ecology SC Environmental Sciences & Ecology GA 281XZ UT WOS:000085187900002 ER PT J AU Skillman, JB Garcia, M Winter, K AF Skillman, JB Garcia, M Winter, K TI Whole-plant consequences of Crassulacean acid metabolism for a tropical forest understory plant SO ECOLOGY LA English DT Article DE Aechmea magdalenae; Barro Colorado Island; biomass allocation; bromeliad; C-3; Crassulacean acid metabolism; niche; Panama; photosynthesis; plant growth; sunflecks; tropical forest ID TERRESTRIAL CAM BROMELIAD; PHOTOSYNTHETIC ACCLIMATION; ANANAS-COMOSUS; HUMILIS JACQ; LIGHT; PHOTOINHIBITION; PATTERNS; CARBON; SHADE; HERBS AB We examined leaf and whole-plant characteristics in mature individuals of several herbaceous species growing in the understory of a tropical moist forest in central Panama. Our objective was to see if contrasts in leaf physiology among Crassulacean acid metabolism (CAM) and C-3 plants were associated with differences in whole-plant structure or performance in a habitat that is considered atypical for CAM. Foliage of Aechmea magdalenae, an understory CAM bromeliad, has a higher maximum photosynthesis rate, and greater nitrogen, chlorophyll, and water contents on a leaf-area basis compared to three sympatric C-3 species. Leaf characteristics of two other understory CAM bromeliads, Ananas comosus and Bromelia plumieri, were similar to that of Aechmea. Aechmea, compared to three sympatric C-3 species, allocates less biomass to roots and more to foliage. The annual aboveground relative growth of Aechmea was lower than it was for the C-3 species, despite Aechmea's higher photosynthetic capacity. This is consistent with the hypothesis that the efficient use of transient periods of high light for carbon gain is critical to the success of this CAM species as an understory plant. Maximum growth in Aechmea occurred during the dry season, whereas for the C-3 species growth was greatest during the wet season, suggesting that variation in photosynthetic pathway can provide a basis for temporal niche differentiation among tropical forest herbaceous perennials. C1 Smithsonian Trop Res Inst, Balboa, Panama. RP Skillman, JB (reprint author), Calif State Univ San Bernardino, Dept Biol, San Bernardino, CA 92407 USA. NR 53 TC 20 Z9 20 U1 0 U2 4 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 0012-9658 J9 ECOLOGY JI Ecology PD JUL PY 1999 VL 80 IS 5 BP 1584 EP 1593 DI 10.1890/0012-9658(1999)080[1584:WPCOCA]2.0.CO;2 PG 10 WC Ecology SC Environmental Sciences & Ecology GA 281XZ UT WOS:000085187900009 ER PT J AU Wright, SJ Carrasco, C Calderon, O Paton, S AF Wright, SJ Carrasco, C Calderon, O Paton, S TI The El Nino Southern Oscillation variable fruit production, and famine in a tropical forest SO ECOLOGY LA English DT Article DE Barro Colorado Island, Republic of Panama; Dasyprocta punctata; El Nino Southern Oscillation; famine; fruit and seed production; Mazama americana; Nasua narica; Odocoileus virginianus; Panama; Sciurus granatensis; Tayassu tajacu; tropical forest ID PECCARIES TAYASSU-TAJACU; BARRO-COLORADO ISLAND; NEOTROPICAL FORESTS; MAMMAL COMMUNITY; CLIMATE-CHANGE; PATTERNS; PANAMA; TREE; PHENOLOGY; CONSEQUENCES AB We tested the hypothesis that the El Nifio Southern Oscillation influences forest-wide fruit production, which, in turn, limits frugivorous and granivorous mammals on Barro Colorado Island (BCI)I Panama. Observations of BCI mammals have been compiled for 49 years. Frugivorous mammals experienced famine between September and January in 1931-1932, 1958-1959, 1970-1971, and 1993-1994. The most recent famine is evident from an 11-yr record of natural deaths of mammals and a 2-yr record of population densities. Famine occurred every time a mild dry season followed an El Nino event in the 49-yr record. This coincidence is statistically improbable, as demonstrated by a randomization test. A 2-yr cycle of high, then low community-level fruit production has been observed twice for BCI when a mild dry season followed an El Nino event. We used 260 litter traps to monitor community- and species-level fruit production from 1 January 1987 through 30 June 1996. Community-level fruit production was greatest during the 1992 El Nino event and lowest one year later, after the mild 1993 dry season. We also reinterpret an earlier 2-yr record of fruit production in light of our 9.5-yr record of fruit production. Community-level fruit production was elevated during the 1969 El Nino event and was very low one year later, after the mild 1970 dry season. We hypothesize that (1) El Nino conditions enhance fruit production: (2) high fruit production consumes stored reserves, limiting the next reproductive event; and (3) mild dry seasons reduce fruit production. Each plant species may respond to any combination of the three components of this hypothesis. Community-level fruit production is extremely low when species sensitive to components 1 and 2 are entrained with species sensitive to component 3, or when a mild dry season follows one year after an El Nino event. El Nino events bring dry, sunny conditions to BCI and a large portion of the wet tropics, Drought and sun may both favor fruit production in wet tropical forests, Drought is known to synchronize flowering, and sunny conditions may relieve light limitation. The El Nine Southern Oscillation has a strong 24-mo periodicity. This creates a strong tendency for dry, sunny years to alternate with wet, cloudy years in Central America and elsewhere in the tropics. We present evidence that this alternately enhances and reduces fruit production on BCI. Terborgh hypothesized that predators regulate frugivorous mammals in tropical forests. As a corollary, he further hypothesized that famines occur on BCI because several large predators are absent and frugivores escape predation. We extended censuses to the nearby mainland to evaluate this hypothesis. Poachers, who are active on the mainland, reduce the abundances of game species below levels maintained in the presence of large felids and raptors. There was evidence for famine in poached, mainland populations, and we rejected the hypothesis that reduced predation pressure is a prerequisite for famine. C1 Smithsonian Trop Res Inst, Balboa, Ancon, Panama. RP Wright, SJ (reprint author), Smithsonian Trop Res Inst, Apartado 2072, Balboa, Ancon, Panama. RI Wright, Stuart/M-3311-2013 OI Wright, Stuart/0000-0003-4260-5676 NR 67 TC 202 Z9 212 U1 12 U2 67 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 0012-9658 J9 ECOLOGY JI Ecology PD JUL PY 1999 VL 80 IS 5 BP 1632 EP 1647 DI 10.1890/0012-9658(1999)080[1632:TENOSO]2.0.CO;2 PG 16 WC Ecology SC Environmental Sciences & Ecology GA 281XZ UT WOS:000085187900013 ER PT J AU Littler, MM Littler, DS AF Littler, MM Littler, DS TI Blade abandonment/proliferation: A novel mechanism for rapid epiphyte control in marine macrophytes SO ECOLOGY LA English DT Article DE Avrainvillea; Belize; coral reefs; epiphytism; seagrass beds; siphonalean algae; Thersandrus compressus ID AVRAINVILLEA-LONGICAULIS; THALASSIA-TESTUDINUM; CORALLINE ALGA; ZOSTERA-MARINA; PRODUCTIVITY; CHLOROPHYTA; HERBIVORES; REEF; PHOTOSYNTHESIS; BRYOPSIDALES AB The strategy of blade abandonment and simultaneous rapid proliferation (via protoplasmic translocation) is unique to siphonaceous macroalgae owing to their lack of restrictive crosswalls. Siphonalean green algae often dominate the standing stocks and productivity of Caribbean mangrove island environs and are also abundant in virtually all calm-water reef habitats. The experimental organism Avrainvillea longicaulis is particularly abundant in the study sites west of Carrie Bow Cay and Curlew Gay, Belize. The recycling of protoplasm out of older epiphytically impaired blades of A. longicaulis, and simultaneous formation of apical siphon extensions elsewhere, leads to rapid proliferation of new blades-hypothetically, at relatively low energy cost to the plant. The rapidity of siphon extension occurs at least an order of magnitude faster than that possible by photosynthetic production alone, resulting in fully formed proliferations within 3 d. At the same time, the older epiphytized blades become empty, first at the tips, then progressively toward the holdfast, appearing translucent-brown and flaccid within 3 d, followed by senescence. We hypothesize that A. longicaulis rapidly responds to epiphyte colonization/impairment by reallocating protoplasm for new growth through protoplasmic streaming. The alternative hypothesis, that the herbivorous crab Thersandrus compressus might beneficially control epiphytes on A. longicaulis, was falsified by its strong negative effects (i.e., decreased growth and increased host mortality). The hypothesis that allelopathic secondary chemicals may play an antifouling role also was not supported by our experiments; i.e., the consistently vigorous growth rates of the five dominant epiphyte species attached to A. longicaulis were not significantly less than populations of the same species attached to carbonate rock. All of the manipulative results (i.e., experimental induction of blade abandonment followed by new proliferation), as well as the populational survey findings (i.e., greater proliferation by epiphytized plants) and physiological data (i.e., photosynthetic inhibition by epiphytes), support the blade abandonment/proliferation hypothesis, thereby documenting an effective epiphyte-control strategy. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. Harbor Branch Oceanog Inst Inc, Div Marine Sci, Ft Pierce, FL 34946 USA. RP Littler, MM (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, MRC 166, Washington, DC 20560 USA. NR 52 TC 37 Z9 39 U1 2 U2 14 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 0012-9658 J9 ECOLOGY JI Ecology PD JUL PY 1999 VL 80 IS 5 BP 1736 EP 1746 PG 11 WC Ecology SC Environmental Sciences & Ecology GA 281XZ UT WOS:000085187900023 ER PT J AU Worthington, W AF Worthington, W TI Air-conditioning America: Engineers and the controlled environment, 1900-1960. SO ENVIRONMENTAL HISTORY LA English DT Book Review C1 Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. RP Worthington, W (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ENVIRONMENTAL HISTORY PI DURHAM PA 701 VICKERS AVE, DURHAM, NC 27701-3147 USA SN 1084-5453 J9 ENVIRON HIST JI Environ. Hist. PD JUL PY 1999 VL 4 IS 3 BP 450 EP 452 DI 10.2307/3985149 PG 3 WC Environmental Studies; History SC Environmental Sciences & Ecology; History GA 256BZ UT WOS:000083706700020 ER PT J AU Cocroft, RB AF Cocroft, RB TI Parent-offspring communication in response to predators in a subsocial treehopper (Hemiptera : Membracidae : Umbonia crassicornis) SO ETHOLOGY LA English DT Article ID ALARM SIGNALS; GROUND-SQUIRRELS; BEHAVIOR; EVOLUTION; HOMOPTERA; CALLS; DEFENSE; INVESTMENT; ALTRUISM; BENEFITS AB The defense of offspring from predators is an important aspect of maternal care in the treehopper Umbonia crassicornis. Nymphal offspring develop in a dense cluster around a host plant stem; and laboratory studies show that they can solicit maternal defense using synchronized vibrational signals. Understanding the function of communication: however, requires not only an experimental investigation of the responses of receivers, but also a description of the context in which signaling takes place in nature. In this study I asked how offspring and parents signal in response to natural predators in the field. I filmed parent-offspring groups to record the behavior of U. crassicornis and their wasp predators (Hymenoptera: Vespidae: Pseudopolybia compressa), along with the substrate-borne vibrational signals produced within the group. I compared the signaling behavior of nymphs, and their mothers, in three contexts: when the family group was undisturbed, when a predatory wasp was present, and when the predator had departed. I assessed the importance of nymphal signals in recruiting the female's initial response by determining whether females or their offspring responded first to a predator's approach. The nymphs produced few synchronized signals when undisturbed, but increased their signaling rate 150-fold in the presence of a wasp. The nymphs continued to signal as long as the wasp was present, and in some cases after it had left, especially if the wasp had contacted or removed a nymph during the encounter. During a wasp's first approach, females responded before the offspring signaled in over half the encounters. Taken together, these results suggest that offspring signals function to influence the mother's behavior throughout a predator encounter, not just to alert her when the predator first appears. Defending females produced signals at a low rate throughout the day and did not significantly increase this rate when a wasp approached. Instead, females began signaling at a high rate only after a wasp had departed. Maternal signals map function to reduce nymphal dispersal after predation events, to reduce the costs of vigilance, or to modify nymphal signaling thresholds in the event of a re-encounter. Both offspring and their mothers, then, signal in response to predators, but using different signals and at different stages of a predation event. In conjunction with experimental studies of signal function, these results show that communication is important in maternal defense of offspring in these subsocial insects. C1 Smithsonian Trop Res Inst, APO AA, Unit 0948, Miami, FL 34002 USA. RP Cocroft, RB (reprint author), Smithsonian Trop Res Inst, APO AA, Unit 0948, Miami, FL 34002 USA. NR 66 TC 33 Z9 33 U1 1 U2 7 PU BLACKWELL WISSENSCHAFTS-VERLAG GMBH PI BERLIN PA KURFURSTENDAMM 57, D-10707 BERLIN, GERMANY SN 0179-1613 J9 ETHOLOGY JI Ethology PD JUL PY 1999 VL 105 IS 7 BP 553 EP 568 PG 16 WC Psychology, Biological; Behavioral Sciences; Zoology SC Psychology; Behavioral Sciences; Zoology GA 217BW UT WOS:000081480500001 ER PT J AU Hughes, NC Chapman, RE Adrain, JM AF Hughes, NC Chapman, RE Adrain, JM TI The stability of thoracic segmentation in trilobites: a case study in developmental and ecological constraints SO EVOLUTION & DEVELOPMENT LA English DT Article ID CAMBRIAN TRILOBITES; CLASSIFICATION; EVOLUTION; HYPOTHESES; ONTOGENY; CANADA; GENES AB The decline in origination rate of new metazoan body plans following the Cambrian radiation has been suggested to reflect developmental canalization in derived taxa, limiting their ability to evolve forms with radically different morphotypes. Segmentation is a fundamental aspect of arthropod body plan, and here we show that a derived trilobite that secondarily converged on a morphotype characteristic of basal members of the clade also reverted to a pattern of segmental variability common among basal trilobites. Hence a secular trend in loss of variability of the trilobite thorax was not due to the evolution of an inviolable developmental constraint. This result challenges the notion of developmental canalization in phylogenetically derived taxa. Rather, early variability in trilobites may be the result of ecological factors that promoted segment-rich thoracic morphotypes during Cambrian time. C1 Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA. Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. Univ Iowa, Dept Geol, Iowa City, IA 52242 USA. RP Hughes, NC (reprint author), Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA. NR 46 TC 46 Z9 48 U1 1 U2 6 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 1520-541X J9 EVOL DEV JI Evol. Dev. PD JUL-AUG PY 1999 VL 1 IS 1 BP 24 EP 35 DI 10.1046/j.1525-142x.1999.99005.x PG 12 WC Evolutionary Biology; Developmental Biology; Genetics & Heredity SC Evolutionary Biology; Developmental Biology; Genetics & Heredity GA 301QE UT WOS:000086320200007 PM 11324017 ER PT J AU Woo, R Habbal, SR AF Woo, R Habbal, SR TI Radial evolution of density structure in the solar corona SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PHYSICAL-PROPERTIES; SCALE STRUCTURES; WIND; MINIMUM; SLOW AB White-light measurements made by the SOHO coronagraphs (LASCO for Large Angle Spectrometric Coronagraph) and the HAO Mauna Loa Mk III K-coronameter are combined to follow the evolution of path-integrated density structure in the solar corona overlying both coronal hole and quiet Sun regions from 1.15 to 5.5 R-o. The global imaging provided by these two instruments confirms and strengthens earlier results discovered by spacecraft radio ranging measurements [Woo and Habbal, 1999], that the imprint of density structure at the Sun - as manifested in the background latitudinal density profile closest to the Sun at 1.15 R-o - is carried essentially radially into interplanetary space with the same density gradient. The only exceptions are coronal streamers that evolve into the heliospheric current sheet within a few solar radii of the Sun. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Smithsonian Ctr Astrophys, Belmont, MA 02178 USA. RP Woo, R (reprint author), CALTECH, Jet Prop Lab, MS 238-725,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 24 Z9 24 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 1 PY 1999 VL 26 IS 13 BP 1793 EP 1796 DI 10.1029/1999GL900366 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 213TU UT WOS:000081290000003 ER PT J AU Kaghashvili, EK AF Kaghashvili, EK TI Ion-cyclotron wave dissipation channel for Alfven waves SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND; ACCELERATION AB The effect of inhomogeneous velocity flow on Alfven wave dynamics in the solar wind is investigated. Unlike existing studies in this field that model energy deposition from high-frequency waves to solar wind particles, we consider here the possibility of obtaining high-frequency waves (in this case fast magnetosonic waves) from the ordinary Alfven wave spectrum. It is shown that the spatial inhomogeneity of the velocity field can lead to dissipation of Alfven waves through ion-cyclotron resonance. Recent Ultraviolet Coronagraph Spectrometer (UVCS/SOHO) observations indicate that preferential heating and acceleration of heavy ions occurs close to the Sun. The process described here provides a possible interpretation of such solar wind observations. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Abastumani Astrophys Observ, Tbilisi, Rep of Georgia. RP Kaghashvili, EK (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 24 TC 23 Z9 23 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 1 PY 1999 VL 26 IS 13 BP 1817 EP 1820 DI 10.1029/1999GL900343 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 213TU UT WOS:000081290000009 ER PT J AU Cutler, A AF Cutler, A TI Joystick nation: How video games ate our quarters, stole our hearts, and rewired our minds SO IEEE ANNALS OF THE HISTORY OF COMPUTING LA English DT Book Review C1 Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. RP Cutler, A (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1058-6180 J9 IEEE ANN HIST COMPUT JI IEEE Ann. Hist. Comput. PD JUL-SEP PY 1999 VL 21 IS 3 BP 77 EP 78 DI 10.1109/MAHC.1999.778993 PG 2 WC Computer Science, Theory & Methods; History & Philosophy Of Science SC Computer Science; History & Philosophy of Science GA 216XQ UT WOS:000081470100023 ER PT J AU Tudge, CC AF Tudge, CC TI Spermatophore morphology in the hermit crab families Paguridae and Parapaguridae (Paguroidea, Anomura, Decapoda) SO INVERTEBRATE REPRODUCTION & DEVELOPMENT LA English DT Article DE Spermatophores; spermatozoa; hermit crabs; Paguridae; Parapaguridae; accessory ampullae ID ULTRASTRUCTURE AB The spermatophore morphology is described and illustrated for 11 species of pagurid hermit crab. All possess a typical tripartite, pedunculate spermatophore characteristic of paguroid anomurans. In the majority of species an accessory ampulla is present at the base of the sperm-filled main ampulla of the spermatophore. This accessory ampulla is attached to the peduncle of the spermatophore, or is incorporated into it, and may or may not contain any spermatozoa. The spermatophores of Pagurus chevreuxi, Solitariopagurus tuerkayi and Xylopagurus caledonicus lack an obvious accessory ampulla. Transmission electron microscopy reveals that the wall and peduncle of the accessory ampullae of Pagurus bernhardus are identical in appearance to, and continuous with, the same structures on the main ampullae. The stalk and spermatophore wall in both accessory and main ampullae in P. bernhardus are composed of a homogeneous, finely grained matrix of moderate electron-density. Like the main ampullae, the accessory ampullae of P. bernhardus have a lateral ridge present around their peripheral edge. Two species of the parapagurid hermit crab genus Sympagurus also possess spermatophores with accessory ampullae adjacent to the main ampullae. C1 Museum Victoria, Crustacean Lab, Abbotsford, Vic 3067, Australia. RP Tudge, CC (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. NR 40 TC 23 Z9 23 U1 0 U2 1 PU INT SCIENCE SERVICES/BALABAN PUBLISHERS PI REHOVOT PA PO BOX 2039, REHOVOT 76120, ISRAEL SN 0168-8170 J9 INVERTEBR REPROD DEV JI Invertebr. Reprod. Dev. PD JUL PY 1999 VL 35 IS 3 BP 203 EP 214 DI 10.1080/07924259.1999.9652386 PG 12 WC Reproductive Biology; Zoology SC Reproductive Biology; Zoology GA 230YV UT WOS:000082280000004 ER PT J AU Zotz, G Bermejo, P Dietz, H AF Zotz, G Bermejo, P Dietz, H TI The epiphyte vegetation of Annona glabra on Barro Colorado Island, Panama SO JOURNAL OF BIOGEOGRAPHY LA English DT Article DE biodiversity; Barro Colorado Island; crassulacean acid metabolism; community dissimilarity; epiphytes; species distribution ID CRASSULACEAN ACID METABOLISM; VASCULAR EPIPHYTES; CLOUD FOREST; RAIN-FOREST; COSTA-RICA; SPATIAL-DISTRIBUTION; SPECIES RICHNESS; CENTRAL VERACRUZ; WATER RELATIONS; SUBSTRATE USE AB Aim Information on the community composition, structure, and dynamics of epiphyte vegetation is scarce. A survey of the epiphytes occurring on all individuals of one particular host tree species in a well-studied neotropical research site allowed us a comparison of the epiphyte flora of this tree with the local epiphyte flora, the analysis of spatial distribution patterns and the use of these patterns as indications for changes in time. In the future, our results can be used as a baseline data-set for the direct observation of the long-term dynamics in epiphyte: communities. Location The study was conducted on Barro Colorado Island (BCI), Panama. Methods We recorded all individuals of the vascular epiphytes growing on Annona glabra L., a flood-tolerant, multiple-stemmed tree, which is restricted to the shoreline of BCI. Data on tree biometrics, epiphyte species, and epiphyte abundances were collected for more than 1200 trees. Results In total, we encountered almost 15,000 epiphytic individuals in sixty-eight species, corresponding to more than one third of the entire epiphyte flora of Barro Colorado Island. The component species differed strongly in abundance: the four most important species accounted for >75% of all individuals. In most cases, the same four species were also the first to colonize a tree (=phorophyte). Colonization patterns indicated no replacement of early colonizers by late arrivals. Species richness and epiphyte abundances showed a positive correlation with the size and the density of the host trees. All species showed a highly clumped distribution and the physiognomy of epiphyte communities of individual trees was dominated either by one or several of the four most common species or by a set of frequently co-occurring tank bromeliads. Other species were dominant only in exceptional cases. Most species were always rare. A distance effect on community composition was mostly confined to a local scale with an increased similarity in the species assemblage of stems of a tree v. neighbouring trees. Main conclusions The epiphytes on a single small phorophyte species may encompass a surprisingly large proportion of the local epiphyte: nora. The observations that most tree crowns are inhabited by a single or only very few species, and that all epiphyte species show highly clumped distributions suggest a predominance of very local dispersal within a tree crown, which is only infrequently interrupted by successful long-distance dispersal between crowns. C1 Univ Wurzburg, Lehrstuhl Bot 2, D-97082 Wurzburg, Germany. Smithsonian Trop Res Inst, Balboa, Panama. RP Zotz, G (reprint author), Univ Wurzburg, Lehrstuhl Bot 2, Julius-von-Sachs-Pl 3, D-97082 Wurzburg, Germany. NR 61 TC 43 Z9 49 U1 2 U2 12 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0305-0270 J9 J BIOGEOGR JI J. Biogeogr. PD JUL PY 1999 VL 26 IS 4 BP 761 EP 776 DI 10.1046/j.1365-2699.1999.00304.x PG 16 WC Ecology; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 273AV UT WOS:000084684400005 ER PT J AU Kim, JH Liu, WK Yuan, JM AF Kim, JH Liu, WK Yuan, JM TI Classical-quantum correspondence in multiphoton dissociation of diatomic molecules by chirped laser pulses SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL-EXCITATION; MORSE OSCILLATOR; DYNAMICS; CHAOS; IONIZATION; FREQUENCY; ATOMS; FIELD AB The classical and quantum dynamics of diatomic molecules driven by chirped laser pulses are investigated, with particular attention given to the dependence of the classical-quantum correspondence on the microscopic parameters of the systems. For this purpose, several molecules with different effective Planck's constants are employed and their respective results are compared. Based on the bucket dynamics which has been successfully applied to explain the dissociation mechanism, we propose a criterion that determines whether a particular molecule will show a good correspondence between classical and quantum calculations in a given parameter region. It is found that, when the size of the bucket is bigger than the effective Planck's constant, the classical predictions of dissociation probabilities agree well with the quantum mechanical results. (C) 1999 American Institute of Physics. [S0021-9606(99)00324-4]. C1 Univ Waterloo, Dept Phys, Guelph Waterloo Program Grad Work Phys, Waterloo, ON N2L 3G1, Canada. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Drexel Univ, Dept Phys & Atmospher Sci, Philadelphia, PA 19104 USA. RP Kim, JH (reprint author), Univ Waterloo, Dept Phys, Guelph Waterloo Program Grad Work Phys, Waterloo, ON N2L 3G1, Canada. NR 26 TC 14 Z9 14 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1999 VL 111 IS 1 BP 216 EP 226 DI 10.1063/1.479267 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 208MQ UT WOS:000080995500027 ER PT J AU Korine, C Zinder, O Arad, Z AF Korine, C Zinder, O Arad, Z TI Diurnal and seasonal changes in blood composition of the free living Egyptian fruit bat (Rousettus aegyptiacus) SO JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL PHYSIOLOGY LA English DT Article DE blood biochemistry; diet; frugivore bats; hematology ID WATER RESTRICTION; PERIPHERAL-BLOOD; FLYING FOX; NITROGEN; WILD; VESPERTILIONIDAE; OSMOREGULATION; UNDERNUTRITION; CONSUMPTION; TEMPERATURE AB We studied the blood profile of the free-living fruit bat (Rousettus aegyptiacus) during the beginning of the activity period (around various feeding trees) and upon return to the day roost during 1994-1995. Results of the present study suggest that during winter and early spring bats are characterized by a poor physical and physiological state as reflected in the blood profile, revealing elevated urea and uric acid concentrations. It was found that at the end of the resting phase, R. aegyptiacus was in a mild state of dehydration (increased hematocrit and hemoglobin levels). At the end of activity, upon return to the day roost, both hematocrit and hemoglobin levels decreased but bats still maintained a high plasma osmolality. Several components in the blood are effected by the feeding time and show a cyclic change in concentration. The reverse relationship between glucose and triglyceride levels may indicate that glucose is the energy source during the active phase and that fat is the energy source during the resting period. The low cholesterol level in the blood reflects its absence in the fruit diet. C1 Technion Israel Inst Technol, Dept Biol, IL-32000 Haifa, Israel. Technion Israel Inst Technol, Dept Med, IL-32000 Haifa, Israel. RP Korine, C (reprint author), Smithsonian Trop Res Inst, POB 2072, Balboa, Panama. RI Korine, Carmi/F-4116-2012 NR 36 TC 15 Z9 15 U1 3 U2 15 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0174-1578 J9 J COMP PHYSIOL B JI J. Comp. Physiol. B-Biochem. Syst. Environ. Physiol. PD JUL PY 1999 VL 169 IS 4-5 BP 280 EP 286 DI 10.1007/s003600050222 PG 7 WC Physiology; Zoology SC Physiology; Zoology GA 223GZ UT WOS:000081834300006 PM 10466219 ER PT J AU Coats, DW AF Coats, DW TI Parasitic life styles of marine dinoflagellates SO JOURNAL OF EUKARYOTIC MICROBIOLOGY LA English DT Article; Proceedings Paper CT Joint Symposium of the Phycological-Society-of-America / International-Society-for-Evolutionary-Protistology / Society-of-Protozoologists CY AUG 01-08, 1998 CL FLAGSTAFF, ARIZONA SP Phycolog Soc Amer, Int Soc Evolutionary Protistol, Soc Protozoologists DE disease; crabs; epizootic; fish; parasitism; protists ID CRABS CHIONOECETES-BAIRDI; LOBSTER NEPHROPS-NORVEGICUS; AMYLOODINIUM-OCELLATUM; N-SP; HEMATODINIUM SP; CHESAPEAKE BAY; CALLINECTES-SAPIDUS; INFECTION; COPEPOD; CYCLE AB Several genera of marine dinoflagellates contain species that have evolved parasitic life styles. Dinoflagellate infections have been reported for a wide range of host organisms including sarcodines, ciliates, free-living dinoflagellates, Various invertebrates, and a few vertebrates. Some dinoflagellates even parasitize other parasitic dinoflagellates. Most species are obligately parasitic and rely on heterotrophy as their sole means of nutrition: however, some are mixotrophic, as they possess chloroplasts during part or all of their life cycle. Many are ectoparasites that use highly specialized structures to attach to their host and feed, while others are intracellular parasites that feed by osmotrophy. Parasitic dinoflagellates often have adverse effects on their host that can lead to reproductive castration or death. The ecological importance of parasitic dinoflagellates is particularly evident during epidemic outbreaks that cause mass mortality of host organisms. Species that infect fish can pose threats to aquaculture, while other species can make commercially important crustacea unpalatable. In the planktonic realm, parasitic dinoflagellates influence the structure and function of the microbial food web. They compete with copepods and other grazers by utilizing ciliates as hosts and can stimulate rapid recycling of nutrients by causing the decline of toxic and non-toxic red tides. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Coats, DW (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. NR 112 TC 77 Z9 82 U1 2 U2 20 PU SOC PROTOZOOLOGISTS PI LAWRENCE PA 810 E 10TH ST, LAWRENCE, KS 66044 USA SN 1066-5234 J9 J EUKARYOT MICROBIOL JI J. Eukaryot. Microbiol. PD JUL-AUG PY 1999 VL 46 IS 4 BP 402 EP 409 DI 10.1111/j.1550-7408.1999.tb04620.x PG 8 WC Microbiology SC Microbiology GA 225ED UT WOS:000081944700011 ER PT J AU Crooks, JA Khim, HS AF Crooks, JA Khim, HS TI Architectural vs. biological effects of a habitat-altering, exotic mussel, Musculista senhousia SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Review DE ecosystem engineering; facilitation; habitat modification; mytilidae; non-indigenous species ID ADULT-LARVAL INTERACTIONS; MACROINVERTEBRATE COMMUNITIES; POSITIVE INTERACTIONS; DREISSENA-POLYMORPHA; FOULING COMMUNITY; SPECIES-DIVERSITY; FIELD EXPERIMENTS; ABUNDANCE; PATTERNS; BAY AB Musculista senhousia Benson in Canter is a small mytilid mussel that has been introduced from Asia onto three continents, including the Pacific coast of North America. The mussel often forms dense mats that can increase infaunal density and species richness. This research experimentally examines the relationship between the physical structure of the mussel mat habitat and the biological activities of the mussel as it relates to the macrofaunal assemblages in Mission Bay, San Diego, California, USA. The results of this experiment demonstrate that the effects of physical structure consistently outweigh the effects of living mussels. Total macrofaunal densities, species richness, and densities of a variety of taxa (e.g. the snail Barleeia subtenuis Carpenter, nemerteans, and amphipods) were enhanced by the presence of the artificial mats. The tube-building, planktonically-developing polychaete, Pseudopolydora paucibranchiata Okuda, however, was apparently inhibited by mats, as were planktonic developers as a group. The effects of structure provided by mussel shells themselves appeared to be weaker than the mat effects, although some taxa, such as the gastropod B. subtenuis, responded to shells alone. The influences of living mussels also were less pronounced than that of artificial mats, although non-planktonic developers, including midge larvae and the tanaid Leptochelia dubia Kroger, showed positive responses to live mussels. In general, these results are consistent with observed effects of other habitat-creating exotics, and suggest that facilitation of biota by non-native species capable of creating physical complexity in ecosystems may be a major and predictable consequence of biological invasions. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. RP Crooks, JA (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. NR 102 TC 143 Z9 148 U1 0 U2 23 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD JUL 1 PY 1999 VL 240 IS 1 BP 53 EP 75 DI 10.1016/S0022-0981(99)00041-6 PG 23 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 214FG UT WOS:000081317500004 ER PT J AU Ubelaker, DH AF Ubelaker, DH TI Ales Hrdlicka's role in the history of forensic anthropology SO JOURNAL OF FORENSIC SCIENCES LA English DT Article; Proceedings Paper CT 50th Annual Meeting of the American-Academy-of-Forensic-Sciences CY FEB 13, 1998 CL SAN FRANCISCO, CALIFORNIA SP Amer Acad Forens Sci DE forensic science; forensic anthropology; Hrdlicka; William R. Maples AB Although Ales Hrdlicka (1869-1943) is widely recognized as a central figure in the development of American physical anthropology, his contributions to forensic anthropology are not well known. The record shows he: I)had training in legal medicine; 2) researched and published on issues of broad medico-legal interest; 3) reported on autopsies; 4) analyzed skeletal cases; 5) researched and testified on ancestry issues; and 6) maintained contact with FBI officials on medico-legal matters. His efforts in research and building collections helped to build the foundation for modern forensic anthropology. C1 Natl Museum Nat Hist, Smithsonian Inst, Dept Anthropol, Washington, DC 20560 USA. RP Ubelaker, DH (reprint author), Natl Museum Nat Hist, Smithsonian Inst, Dept Anthropol, MRC 112, Washington, DC 20560 USA. NR 25 TC 4 Z9 4 U1 0 U2 2 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0022-1198 J9 J FORENSIC SCI JI J. Forensic Sci. PD JUL PY 1999 VL 44 IS 4 BP 724 EP 730 PG 7 WC Medicine, Legal SC Legal Medicine GA 293AY UT WOS:000085830400015 ER PT J AU Emardson, TR Jarlemark, POJ AF Emardson, TR Jarlemark, POJ TI Atmospheric modelling in GPS analysis and its effect on the estimated geodetic parameters SO JOURNAL OF GEODESY LA English DT Article DE space geodesy; Global Positioning System; Kalman filtering; atmospheric modelling ID GLOBAL POSITIONING SYSTEM; GRADIENTS; DELAY AB Permanently operating Global Positioning System (GPS) receivers are used today, for example, in precise positioning and determination of atmospheric water vapour content. The GPS signals are delayed by various gases when traversing the atmosphere. The delay due to water vapour, the wet delay, is difficult to model using ground surface data and is thus often estimated from the GPS data. In order to obtain the most accurate results from the GPS processing, a modelling of the horizontal distribution of the wet delay may be necessary. Through simulations, three such models are evaluated, one of which is developed in this paper. In the first model the water vapour is assumed to be horizontally stratified, thus the wet delay can be described by only one zenith parameter. The second model gives the wet delay with one zenith and two horizontal gradient parameters. The third model uses the correlation between the wet-delay values in different directions. It is found that for large gradients and strong turbulence the two latter models yield lower errors in the estimated vertical coordinate and wet-delay parameters. For large gradients this improvement is up to 7 mm in the zenith wet-delay parameter, from 9 mm down to 2 and 4 mm for the second and third models, respectively. C1 Chalmers Univ Technol, Onsala Space Observ, S-43900 Onsala, Sweden. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Emardson, TR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 238-600, Pasadena, CA 91109 USA. NR 17 TC 18 Z9 18 U1 1 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0949-7714 J9 J GEODESY JI J. Geodesy PD JUL PY 1999 VL 73 IS 6 BP 322 EP 331 DI 10.1007/s001900050249 PG 10 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 223GY UT WOS:000081834000004 ER PT J AU Cox, ML Windsor, DM AF Cox, ML Windsor, DM TI The first instar larva of Aulacoscelis appendiculata n. sp (Coleoptera : Chrysomelidae : Aulacoscelinae) and its value in the placement of the Aulacoscelinae SO JOURNAL OF NATURAL HISTORY LA English DT Article DE Coleoptera; Chrysomelidae; Aulacoscelinae; Aulacoscelis; morphology; new species; eggs; larvae; relationships; subfamilies AB Of all of the chrysomelid subfamilies, only the larvae of the Aulacoscelinae remain undescribed. The adults and first instar larva of Aulacoscelis appendiculata sp. n., from Panama are described, as well as the eggs. Larval characters, eggs, and oviposition behaviour are used to relate the Aulacoscelinae with other chrysomelid subfamilies, in support of what is known to date concerning adult morphology. C1 Nat Hist Museum, Dept Entomol, London SW7 5BD, England. Smithsonian Trop Res Inst, Unit 0948, APO, AA 34002 USA. RP Cox, ML (reprint author), Nat Hist Museum, Dept Entomol, Cromwell Rd, London SW7 5BD, England. NR 67 TC 12 Z9 14 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0022-2933 J9 J NAT HIST JI J. Nat. Hist. PD JUL PY 1999 VL 33 IS 7 BP 1049 EP 1087 DI 10.1080/002229399300083 PG 39 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 210XT UT WOS:000081130700007 ER PT J AU Wing, SL AF Wing, SL TI Presentation of the 1998 Charles Schuchert Award to Paul L. Koch SO JOURNAL OF PALEONTOLOGY LA English DT Biographical-Item C1 Smithsonian Inst, Dept Pelobiol, Washington, DC 20560 USA. RP Wing, SL (reprint author), Smithsonian Inst, Dept Pelobiol, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PALEONTOLOGICAL SOC INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD JUL PY 1999 VL 73 IS 4 BP 734 EP 735 PG 2 WC Paleontology SC Paleontology GA 219HD UT WOS:000081601100021 ER PT J AU Roubik, DW Inoue, T Hamid, A Harrison, R AF Roubik, DW Inoue, T Hamid, A Harrison, R TI Height communication by Bornean honey bees (Apiformes : Apidae; Apini) SO JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY LA English DT Article ID MELIPONA-PANAMICA; STINGLESS BEE; HYMENOPTERA AB In forest with emergent trees 70 m in height we tested whether honey bees effectively communicated three-dimensional forage locations to nestmates. Worker Apis koschevnikovi, trained from nests established on a 50 m tree tower, visited feeders on two additional towers, 200 or 60 m distant, at Lambir Hills Field Station, Sarawak. Twenty experiments were run in which bees were trained at one level (0.2-36 m), then 727 total new recruits were recorded at control and experimental feeders separated by at least 13.5 m height. Recruits arrived at all feeders, but experimental feeders (where other bees fed) received significantly more (average 4.9 times that of a control), with the exception of 1 experiment in 20. Systematic or random searching-between canopy and ground, by surveying for odors, or by sighting conspecifics-were ruled out by our findings. Rather, we suggest distance and direction communication, perhaps combined solely with conspecific odor recognition and vertical ranging behavior, in successful three-dimensional recruitment. C1 Smithsonian Trop Res Inst, Balboa, Panama. Kyoto Univ, Ctr Ecol Res, Otsu, Shiga 52001, Japan. RP Roubik, DW (reprint author), Smithsonian Trop Res Inst, Apartado 2072, Balboa, Panama. NR 13 TC 5 Z9 5 U1 0 U2 2 PU KANSAS ENTOMOLOGICAL SOC PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0022-8567 J9 J KANSAS ENTOMOL SOC JI J. Kans. Entomol. Soc. PD JUL PY 1999 VL 72 IS 3 BP 256 EP 261 PG 6 WC Entomology SC Entomology GA 307VA UT WOS:000086673800002 ER PT J AU Zwicker, SM Walters, JR AF Zwicker, SM Walters, JR TI Selection of pines for foraging by red-cockaded woodpeckers SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE foraging; longleaf pine; North Carolina; Picoides borealis; Pinus palustris; red-cockaded woodpecker; tree age; tree size ID HABITAT USE; FLORIDA; AGE AB Foraging habitat guidelines for the endangered red-cockaded woodpecker (Picoides borealis) are based on properties of stands used by the birds rather than properties of the individual trees selected for foraging. If foraging red-cockaded woodpeckers key in on individual trees, rather than stands, there would be significant implications for optimal management of foraging habitat for this species. We compared age and size of pine trees used by foraging red-cockaded woodpeckers to the age and size of pine trees in the surrounding habitat. We hypothesized that older trees and larger trees would be used mere frequently than expected from availability Mean age of trees used was older than mean age of trees available (P < 0.01), and mean tree size used was larger than mean tree size available (P < 0.05). Our data indicate that 60 years and 25 cm are threshold values where use first exceeds availability and that old-growth trees (greater than or equal to 100 yr old) are strongly selected. The Red-cockaded Woodpecker Recover) Plan stipulates that tree stands 30-60 years old constitute suitable foraging habitat. We found that although red-cockaded woodpeckers foraged on trees 30-49 years old, these trees were used considerably less than their availability To better reflect habitat selection, foraging guidelines should place more emphasis on trees greater than or equal to 60 years old, and especially old-growth trees and stands. C1 N Carolina State Univ, Dept Zool, Raleigh, NC 27695 USA. RP Zwicker, SM (reprint author), Smithsonian Inst, Natl Zool Pk, Friends Natl Zoo, Off Commun, Washington, DC 20008 USA. RI Zwicker, Susan/R-5520-2016 OI Zwicker, Susan/0000-0001-9070-9766 NR 37 TC 23 Z9 24 U1 3 U2 10 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 USA SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD JUL PY 1999 VL 63 IS 3 BP 843 EP 852 DI 10.2307/3802797 PG 10 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA 216KP UT WOS:000081441500009 ER PT J AU Lukin, MD Yelin, SF Zibrov, AS Scully, MO AF Lukin, MD Yelin, SF Zibrov, AS Scully, MO TI Enhancement of refractive index with quantum coherence: An overview SO LASER PHYSICS LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; CORRELATED SPONTANEOUS-EMISSION; POPULATION-INVERSION; ATOMIC COHERENCE; DISPERSIVE PROPERTIES; 3-LEVEL SYSTEM; LASER; INTERFERENCE; AMPLIFICATION; RESONANCES AB We review recent theoretical and experimental studies on resonant enhancement of the refractive index in phase coherent media. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Max Planck Inst Quantum Opt, D-85748 Garching, Germany. MIT, Elect Res Lab, Cambridge, MA 02138 USA. USAF, Sensors Directorate, Res Lab, Hanscom AFB, MA 01731 USA. RP Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. EM lukin@xena.tamu.edu RI Zibrov, Alexander/G-7419-2014 NR 77 TC 22 Z9 24 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1054-660X EI 1555-6611 J9 LASER PHYS JI Laser Phys. PD JUL-AUG PY 1999 VL 9 IS 4 BP 759 EP 772 PG 14 WC Optics; Physics, Applied SC Optics; Physics GA 230AY UT WOS:000082230000003 ER PT J AU Krot, AN Petaev, MI Brearley, AJ Kallemeyn, GW Sears, DWG Benoit, PH Hutcheon, ID Keil, K AF Krot, AN Petaev, MI Brearley, AJ Kallemeyn, GW Sears, DWG Benoit, PH Hutcheon, ID Keil, K TI In situ growth of fayalite and hedenbergite in the ungrouped carbonaceous chondrite MacAlpine Hills 88107. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID ASTEROIDAL ALTERATION; MOKOIA C1 Univ Hawaii, Hawaii Inst Geophys & Planetol, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Fac Sci, Dept Chem, Tokyo, Japan. Univ Arkansas, Dept Biochem & Chem, Fayetteville, AR 72701 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RI McKeegan, Kevin/A-4107-2008 OI McKeegan, Kevin/0000-0002-1827-729X NR 9 TC 13 Z9 13 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1999 VL 34 SU S BP A68 EP A68 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 223EA UT WOS:000081826400125 ER PT J AU Krot, AN Sahijpal, S McKeegan, KD Weber, D Ulyanov, AA Petaev, MI Meibom, A Keil, K AF Krot, AN Sahijpal, S McKeegan, KD Weber, D Ulyanov, AA Petaev, MI Meibom, A Keil, K TI Unique mineralogy and isotopic signatures of calcium-aluminum-rich inclusions from the CH chondrite Acfer 182. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID EARLY SOLAR-SYSTEM; CARBONACEOUS CHONDRITE; ALH85085 C1 Univ Hawaii, Hawaii Inst Geophys & Planetol, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. Univ Calif Los Angeles, Los Angeles, CA USA. Inst Planetol, Munster, Germany. Moscow MV Lomonosov State Univ, Moscow 117234, Russia. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RI McKeegan, Kevin/A-4107-2008 OI McKeegan, Kevin/0000-0002-1827-729X NR 13 TC 7 Z9 7 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1999 VL 34 SU S BP A69 EP A70 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 223EA UT WOS:000081826400127 ER PT J AU Meibom, A Krot, AN Petaev, MI Wilson, L Reisener, R Goldstein, JI Norman, M Campbell, AJ Bennett, V Nuth, J Wasilewski, P Bland, P Hough, RM Trimby, P Keil, K AF Meibom, A Krot, AN Petaev, MI Wilson, L Reisener, R Goldstein, JI Norman, M Campbell, AJ Bennett, V Nuth, J Wasilewski, P Bland, P Hough, RM Trimby, P Keil, K TI Metal condensates in CH and Bencubbin-like chondrites: Evidence for localized nebula heating events and variations in gas composition. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Univ Hawaii, Sch Ocean & Earth Sci & Technol, Hawaii Inst Geophys, Honolulu, HI 96822 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Lancaster, Inst Environm & Nat Sci, Lancaster, England. Univ Massachusetts, Dept Geosci, Amherst, MA 01003 USA. Univ Massachusetts, Dept Mech & Ind Engn, Amherst, MA 01003 USA. Univ Tasmania, Ctr Ore Deposit Res, Hobart, Tas 7001, Australia. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 2600, Australia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Museum Nat Hist, London, England. Open Univ, Milton Keynes MK7 6AA, Bucks, England. Univ Utrecht, Dept Geol, Utrecht, Netherlands. RI Nuth, Joseph/E-7085-2012 NR 3 TC 2 Z9 2 U1 0 U2 2 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1999 VL 34 SU S BP A80 EP A81 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 223EA UT WOS:000081826400148 ER PT J AU Welten, KC Caffee, MW McCoy, TJ AF Welten, KC Caffee, MW McCoy, TJ TI Lewis Cliff 88019, 88021, and 88174: Three heavily weathered H4 chondrites with low terrestrial ages: Implications for local weathering conditions in Antarctica. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Mass Spectrometry, Livermore, CA 94550 USA. Museum Hist Nat, Smithsonian Inst, Dept Mineral Sci, MRC 119, Washington, DC 20560 USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1999 VL 34 SU S BP A121 EP A121 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 223EA UT WOS:000081826400227 ER PT J AU Gonzalez, P Lessios, HA AF Gonzalez, P Lessios, HA TI Evolution of sea urchin retroviral-like (SURL) elements: Evidence from 40 echinoid species SO MOLECULAR BIOLOGY AND EVOLUTION LA English DT Article DE retrotransposons; sea urchins; reverse transcriptase; horizontal transfer; vertical transmission ID EUKARYOTIC TRANSPOSABLE ELEMENTS; TY1-COPIA GROUP RETROTRANSPOSONS; DROSOPHILA-MELANOGASTER; HORIZONTAL TRANSFER; PHYLOGENETIC ANALYSIS; MOLECULAR EVOLUTION; HYBRID DYSGENESIS; REVERSE-TRANSCRIPTASE; GENUS DROSOPHILA; RATES AB We conducted a phylogenetic survey of sea urchin retroviral-like (SURL) retrotransposable elements in 33 species of the class Echinoidea (sea urchins, sand dollars, and heart urchins). A 263-bp fragment from the coding region of the reverse transcriptase (RT) gene was amplified, cloned, and sequenced. Phylogenetic relationships of the elements isolated from independent clones, along with those from seven additional echinoid species obtained earlier by Springer et al.,, were compared with host phylogeny: Vertical transmission and the presence of paralogous sequences that diverged prior to host speciation:can explain most of the phylogenetic relationships among SURL elements. Rates of evolution were estimated from cases in which SURL and host phylogenies were concordant. In agreement with conclusions reached previously be Springer et al., average rates of synonymous substitution were comparable with those of single-copy sea urchin DNA. High ratios of synonymous to nonsynonymous substitution suggest that the RT of the elements is under strong purifying selection. However, a high proportion (similar to 15%) of elements with deleterious frameshifts and stop codons and an increase of the ratio of synonymous to nonsynonymous substitutions with divergence time show that in the short term this selection is relaxed. Despite, the predominance of vertical transmission, sequence similarity of 83%-94% for SURL elements from hosts that have been separated for 240 Myr suggests four cases of apparent horizontal transfer between the ancestors of the extant echinoid species. In three additional cases, elements with identical RT sequences were found in sea urchin species separated for a minimum of 3 Myr. Thus, horizontal transfer plays a role in the evolution of this retrotransposon family. C1 Smithsonian Trop Res Inst, Balboa, Panama. RP Lessios, HA (reprint author), Smithsonian Trop Res Inst, Box 2072, Balboa, Panama. NR 96 TC 36 Z9 36 U1 2 U2 3 PU SOC MOLECULAR BIOLOGY EVOLUTION PI LAWRENCE PA PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0737-4038 J9 MOL BIOL EVOL JI Mol. Biol. Evol. PD JUL PY 1999 VL 16 IS 7 BP 938 EP 952 PG 15 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA 214VD UT WOS:000081347500006 PM 10406111 ER PT J AU Volkert, J AF Volkert, J TI Closed Mondays SO MUSEUM NEWS LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Volkert, J (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC MUSEUMS PI WASHINGTON PA 1575 EYE ST, NW, STE 400, WASHINGTON, DC 20005 USA SN 0027-4089 J9 MUSEUM NEWS JI Mus. News PD JUL-AUG PY 1999 VL 78 IS 4 BP 21 EP 22 PG 2 WC Art SC Art GA 211PV UT WOS:000081170100013 ER PT J AU Timmermans, E Tommasini, P Hussein, MS Kerman, A AF Timmermans, E Tommasini, P Hussein, MS Kerman, A TI Feshbach resonances in atomic Bose-Einstein condensates SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Article; Proceedings Paper CT Symposium in Honor of Richard Slansky on Looking Forward - Frontiers in Theoretical Science CY MAY 20-21, 1998 CL LOS ALAMOS, NM DE Bose-Einstein condensates; Feshbach resonance; coherent matter wave dynamics ID ATTRACTIVE INTERACTIONS; COLLISIONS; GAS; SCATTERING; FIELDS AB The low-energy Feshbach resonances recently observed in the inter-particle interactions of trapped ultra-cold atoms involve an intermediate quasi-bound molecule with a spin arrangement that differs from the trapped atom spins. Variations of the strength of an external magnetic field then alter the difference of the initial and intermediate state energies (i.e. the 'detuning'). The effective scattering length that describes the low-energy binary collisions, similarly varies with the near-resonant magnetic field. Since the properties of the dilute atomic Bose-Einstein condensates (BECs) are extremely sensitive to the value of the scattering length, a 'tunable' scattering length suggests highly interesting many-body studies. In this paper, we review the theory of the binary collision Feshbach resonances, and we discuss their effects on the many-body physics of the condensate. We point out that the Feshbach resonance physics in a condensate can be considerably richer than that of an altered scattering length: the Feshbach resonant atom-molecule coupling can create a second condensate component of molecules that coexists with the atomic condensate. Far off-resonance, a stationary condensate does behave as a single condensate with effective binary collision scattering length. However, even in the off-resonant limit, the dynamical response of the condensate mixture to a sudden change in the external magnetic field carries the signature of the molecular condensate's presence: experimentally observable oscillations of the number of atoms and molecules. We also discuss the stationary states of the near-resonant condensate system. We point out that the physics of a condensate that is adiabatically tuned through resonance depends on its history, i.e. whether the condensate starts out above or below resonance. Furthermore, we show that the density dependence of the many-body ground-state energy suggests the possibility of creating a dilute condensate system with the liquid-like property of a self-determined density. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Harvard Smithsonian Ctr Astrophys, Inst Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo, Brazil. MIT, Ctr Theoret Phys, Nucl Sci Lab, Cambridge, MA 02139 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. RP Los Alamos Natl Lab, T-4, Los Alamos, NM 87545 USA. EM eddy@t4.lanl.gov NR 46 TC 450 Z9 453 U1 2 U2 30 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 EI 1873-6270 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD JUL PY 1999 VL 315 IS 1-3 BP 199 EP 230 DI 10.1016/S0370-1573(99)00025-3 PG 32 WC Physics, Multidisciplinary SC Physics GA 214LM UT WOS:000081329500013 ER PT J AU Solis, MA AF Solis, MA TI Key to selected Pyraloidea (Lepidoptera) larvae intercepted at US ports of entry: Revision of Pyraloidea in "keys to some frequently intercepted lepidopterous larvae" by D. M. Weisman 1986 SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE continental United States; Florida; Hawaii; hosts; Pyralidae; Crambidae ID LAST-INSTAR LARVAE; PHYLOGENETIC ANALYSIS; PYRALIDAE; NORTH AB A key to frequently intercepted lepidopterous larvae, designed for U.S. Department of Agriculture, Animal and Plant Health Inspection Service (USDA, APHIS) identifiers at U.S. ports, was last revised in 1986. Since then many changes have occurred in the classification, nomenclature, and the nature of commodities being imported into the U.S. In this revision of the section on Pyraloidea, species recently intercepted are included, the most recent generic combinations are used, and families and subfamilies are now included in the key. Distributions are updated, stating if the species occurs in Hawaii or restricted areas of the continental United States. A "Note" section explains changes and additions, and gives references to further information. Two tables are provided, one to the classification of Pyraloidea with reference to placement in the key and another to the hosts and/or commodities. C1 Smithsonian Inst, Natl Museum Amer Hist, USDA ARS, PSI,Systemat Entomol Lab, Washington, DC 20560 USA. RP Solis, MA (reprint author), Smithsonian Inst, Natl Museum Amer Hist, USDA ARS, PSI,Systemat Entomol Lab, Washington, DC 20560 USA. NR 52 TC 9 Z9 11 U1 0 U2 0 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD JUL PY 1999 VL 101 IS 3 BP 645 EP 686 PG 42 WC Entomology SC Entomology GA 218QV UT WOS:000081563900017 ER PT J AU Adamski, D AF Adamski, D TI Humbugs, type specimens, and the identity of Asaphocrita pineae (Amsel 1962), new combination (Gelechioidea : Coleophoridae : Blastobasinae) SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article C1 Smithsonian Inst, Dept Entomol, Washington, DC 20560 USA. RP Adamski, D (reprint author), Smithsonian Inst, Dept Entomol, NHB 169, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD JUL PY 1999 VL 101 IS 3 BP 694 EP 696 PG 3 WC Entomology SC Entomology GA 218QV UT WOS:000081563900021 ER PT J AU Gagne, RJ AF Gagne, RJ TI A type species designation for Actilasioptera Gagne (Diptera : Cecidomyiidae) SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article C1 Smithsonian Inst, Natl Museum Amer Hist, USDA, PSI Agr Res Serv,Systemat Entomol Lab, Washington, DC 20560 USA. RP Gagne, RJ (reprint author), Smithsonian Inst, Natl Museum Amer Hist, USDA, PSI Agr Res Serv,Systemat Entomol Lab, Washington, DC 20560 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD JUL PY 1999 VL 101 IS 3 BP 697 EP 697 PG 1 WC Entomology SC Entomology GA 218QV UT WOS:000081563900023 ER PT J AU Phillips, DF Wong, GP Bear, D Stoner, RE Walsworth, RL AF Phillips, DF Wong, GP Bear, D Stoner, RE Walsworth, RL TI Characterization and stabilization of fiber-coupled laser diode arrays SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID NOBLE-GAS MASER AB We have characterized the spectra and performance of an ensemble of 11 fiber-coupled laser diode arrays (LDAs) manufactured by Opto Power Inc. These high-power LDAs operate near 795 nm and are of a type commonly used for spin-exchange optical pumping of noble gases. We find the Opto Power LDAs to vary significantly in output power, spectral width, and other important characteristics, in a manner not correlated with age, operating lifetime, or information supplied by the manufacturer. In addition we have developed a two-loop feedback technique for use with LDAs that stabilizes the Rb magnetization in an optical pumping cell to better than one part in a thousand. (C) 1999 American Institute of Physics. [S0034-6748(99)00707-8]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Phillips, DF (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Stoner, Richard/0000-0001-7949-6747 NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUL PY 1999 VL 70 IS 7 BP 2905 EP 2909 DI 10.1063/1.1149847 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 210AC UT WOS:000081082100002 ER PT J AU Handy, BN Acton, LW Kankelborg, CC Wolfson, CJ Akin, DJ Bruner, ME Caravalho, R Catura, RC Chevalier, R Duncan, DW Edwards, CG Feinstein, CN Freeland, SL Friedlaender, FM Hoffmann, CH Hurlburt, NE Jurcevich, BK Katz, NL Kelly, GA Lemen, JR Levay, M Lindgren, RW Mathur, DP Meyer, SB Morrison, SJ Morrison, MD Nightingale, RW Pope, TP Rehse, RA Schrijver, CJ Shine, RA Shing, L Strong, KT Tarbell, TD Title, AM Torgerson, DD Golub, L Bookbinder, JA Caldwell, D Cheimets, PN Davis, WN Deluca, EE McMullen, RA Warren, HP Amato, D Fisher, R Maldonado, H Parkinson, C AF Handy, BN Acton, LW Kankelborg, CC Wolfson, CJ Akin, DJ Bruner, ME Caravalho, R Catura, RC Chevalier, R Duncan, DW Edwards, CG Feinstein, CN Freeland, SL Friedlaender, FM Hoffmann, CH Hurlburt, NE Jurcevich, BK Katz, NL Kelly, GA Lemen, JR Levay, M Lindgren, RW Mathur, DP Meyer, SB Morrison, SJ Morrison, MD Nightingale, RW Pope, TP Rehse, RA Schrijver, CJ Shine, RA Shing, L Strong, KT Tarbell, TD Title, AM Torgerson, DD Golub, L Bookbinder, JA Caldwell, D Cheimets, PN Davis, WN Deluca, EE McMullen, RA Warren, HP Amato, D Fisher, R Maldonado, H Parkinson, C TI The transition region and coronal explorer SO SOLAR PHYSICS LA English DT Article ID SOLAR TELESCOPE ARRAY; SOHO MISSION AB The Transition Region and Coronal Explorer (TRACE) satellite, launched 2 April 1998, is a NASA Small Explorer (SMEX) that images the solar photosphere, transition region and corona with unprecedented spatial resolution and temporal continuity. To provide continuous coverage of solar phenomena, TRACE is located in a sun-synchronous polar orbit. The similar to 700 Mbytes of data which are collected daily are made available for unrestricted use within a few days of observation. The instrument features a 30-cm Cassegrain telescope with a field of view of 8.5 x 8.5 arc min and a spatial resolution of 1 arc sec (0.5 arc sec pixels). TRACE contains multilayer optics and a lumogen-coated CCD detector to record three EUV wavelengths and several UV wavelengths. It observes plasmas at selected temperatures from 6000 K to 10 MK with a typical temporal resolution of less than 1 min. C1 Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. Lockheed Martin Palo Alto Adv Technol Ctr, Palo Alto, CA 94304 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Handy, BN (reprint author), Montana State Univ, Dept Phys, POB 173840, Bozeman, MT 59717 USA. RI DeLuca, Edward/L-7534-2013; OI DeLuca, Edward/0000-0001-7416-2895; Golub, Leon/0000-0001-9638-3082 NR 30 TC 886 Z9 898 U1 2 U2 16 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JUL PY 1999 VL 187 IS 2 BP 229 EP 260 DI 10.1023/A:1005166902804 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 240JB UT WOS:000082821200001 ER PT J AU Schrijver, CJ Title, AM Berger, TE Fletcher, L Hurlburt, NE Nightingale, RW Shine, RA Tarbell, TD Wolfson, J Golub, L Bookbinder, JA DeLuca, EE McMullen, RA Warren, HP Kankelborg, CC Handy, BN De Pontieu, B AF Schrijver, CJ Title, AM Berger, TE Fletcher, L Hurlburt, NE Nightingale, RW Shine, RA Tarbell, TD Wolfson, J Golub, L Bookbinder, JA DeLuca, EE McMullen, RA Warren, HP Kankelborg, CC Handy, BN De Pontieu, B TI A new view of the solar outer atmosphere by the Transition Region and Coronal Explorer SO SOLAR PHYSICS LA English DT Article ID STATIONARY SIPHON FLOWS; X-RAY OBSERVATIONS; EXTREME-ULTRAVIOLET; MAGNETIC-FIELD; BRIGHT POINTS; LOOPS; TELESCOPE; MODELS; OSCILLATIONS; BALANCE AB The Transition Region and Coronal Explorer (TRACE) - described in the companion paper by Handy et al. (1999) - provides an unprecedented view of the solar outer atmosphere. In this overview, we discuss the initial impressions gained from, and interpretations of, the first million images taken with TRACE. We address, among other topics, the fine structure of the corona, the larger-scale thermal trends, the evolution of the corona over quiet and active regions, the high incidence of chromospheric material dynamically embedded in the coronal environment, the dynamics and structure of the conductively dominated transition region between chromosphere and corona, loop oscillations and flows, and sunspot coronal loops. With TRACE we observe a corona that is extremely dynamic and full of flows and wave phenomena, in which loops evolve rapidly in temperature, with associated changes in density. This dynamic nature points to a high degree of spatio-temporal variability even under conditions that traditionally have been referred to as quiescent. This variability requires that coronal heating can turn on and off on a time scale of minutes or less along field-line bundles with cross sections at or below the instrumental resolution of 700 km. Loops seen at 171 Angstrom (similar to 1 MK) appear to meander through the coronal volume, but it is unclear whether this is caused by the evolution of the field or by the weaving of the heating through the coronal volume, shifting around for periods of up to a few tens of minutes and lighting up subsequent field lines. We discuss evidence that the heating occurs predominantly within the first 10 to 20 Mm from the loop footpoints. This causes the inner parts of active-region coronae to have a higher average temperature than the outer domains. C1 Stanford Lockheed Inst Space Res, Dept H1 12, Palo Alto, CA 94304 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. RP Stanford Lockheed Inst Space Res, Dept H1 12, Bldg 252,3251 Hanover St, Palo Alto, CA 94304 USA. RI DeLuca, Edward/L-7534-2013; OI DeLuca, Edward/0000-0001-7416-2895; Golub, Leon/0000-0001-9638-3082 NR 39 TC 318 Z9 321 U1 0 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 EI 1573-093X J9 SOL PHYS JI Sol. Phys. PD JUL PY 1999 VL 187 IS 2 BP 261 EP 302 DI 10.1023/A:1005194519642 PG 42 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 240JB UT WOS:000082821200002 ER PT J AU Funk, VA Zermoglio, MF AF Funk, VA Zermoglio, MF TI A revision of Chrysactinium (Compositae : Liabeae) SO SYSTEMATIC BOTANY LA English DT Article AB Chrysactinium (Compositae: Liabeae) is composed of six species, all restricted to the Paramo-type regions of Ecuador and Peru. Chrysactinium longiradiatum and C. rosulatum are considered synonymous with C. acaule because of the high levels of variation exhibited in the characters previously used to distinguish them. C1 Natl Museum Nat Hist, Dept Bot, US Natl Herbarium, Smithsonian Inst, Washington, DC 20560 USA. RP Funk, VA (reprint author), Natl Museum Nat Hist, Dept Bot, US Natl Herbarium, Smithsonian Inst, MRC-166, Washington, DC 20560 USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU AMER SOC PLANT TAXONOMISTS PI BRONX PA NEW YORK BOTANICAL GARDEN, BRONX, NY 10458-5126 USA SN 0363-6445 J9 SYST BOT JI Syst. Bot. PD JUL-SEP PY 1999 VL 24 IS 3 BP 323 EP 338 DI 10.2307/2419693 PG 16 WC Plant Sciences; Evolutionary Biology SC Plant Sciences; Evolutionary Biology GA 253YE UT WOS:000083584100004 ER PT J AU Crouch, TD AF Crouch, TD TI Kill Devil Hills, 17 December 1903 SO TECHNOLOGY AND CULTURE LA English DT Article C1 Smithsonian Inst, Natl Air & Space Museum, Washington, DC 20560 USA. RP Crouch, TD (reprint author), Smithsonian Inst, Natl Air & Space Museum, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4319 USA SN 0040-165X J9 TECHNOL CULT JI Technol. Cult. PD JUL PY 1999 VL 40 IS 3 BP 594 EP 598 PG 5 WC History & Philosophy Of Science SC History & Philosophy of Science GA 221FA UT WOS:000081712300006 ER PT J AU Hershler, R Mulvey, M Liu, HP AF Hershler, R Mulvey, M Liu, HP TI Biogeography in the Death Valley region: evidence from springsnails (Hydrobiidae : Tryonia) SO ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Article DE Colorado River; phylogenetic relationships; evolution; mitochondrial DNA; allozymes; gastropoda; pupfish; Cyprinodon ID SNAIL BIOMPHALARIA-GLABRATA; MITOCHONDRIAL-DNA VARIATION; GENETIC-VARIATION; COLORADO RIVER; SYSTEM; CALIFORNIA; CYPRINODONTIDAE; POPULATIONS; GASTROPODA; EVOLUTION AB Allozyme and mitochondrial DNA variation were analysed to examine evolution of the nine species of springsnails (genus Tryonia) living in the Death Valley system (Owens and Amargosa basins) of southeastern California and southwestern Nevada. Both allozyme and mtDNA evidence indicate that this highly endemic fauna is non-monophyletic. Species from the upper Amargosa basin comprise a clade most closely related to snails living in the Colorado basin. Snails from the lower Amargosa basin (Death Valley trough) reflect a complex evolutionary history and two of these species are more closely related to an estuarine species from western California than to other snails of the region. These results indicate a commonality of pattern with the well-studied Death Valley pupfishes (Cyprinodon), which also are non-monophyletic and include species that are most closely related to Colorado basin congeners. These biogeographic patterns are interpreted within the context of a recently proposed model for the early history of the lower Colorado River. (C) 1999 The Linnean Society of London. C1 Natl Museum Nat Hist, Dept Invertebrate Zool, Smithsonian Inst, Washington, DC 20560 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Hershler, R (reprint author), Natl Museum Nat Hist, Dept Invertebrate Zool, Smithsonian Inst, Washington, DC 20560 USA. NR 55 TC 24 Z9 24 U1 1 U2 3 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0024-4082 J9 ZOOL J LINN SOC-LOND JI Zool. J. Linn. Soc. PD JUL PY 1999 VL 126 IS 3 BP 335 EP 354 DI 10.1111/j.1096-3642.1999.tb01375.x PG 20 WC Zoology SC Zoology GA 218FE UT WOS:000081541900004 ER PT J AU Kash, MM Sautenkov, VA Zibrov, AS Hollberg, L Welch, GR Lukin, MD Rostovtsev, Y Fry, ES Scully, MO AF Kash, MM Sautenkov, VA Zibrov, AS Hollberg, L Welch, GR Lukin, MD Rostovtsev, Y Fry, ES Scully, MO TI Ultraslow group velocity and enhanced nonlinear optical effects in a coherently driven hot atomic gas SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; INTERFERENCE AB We report the observation of small group velocities of order 90 m/s and large group delays of greater than 0.26 ms, in an optically dense hot rubidium gas (approximate to 360 K). Media of this kind yield strong nonlinear interactions between very weak optical fields and very sharp spectral features. The result is in agreement with previous studies on nonlinear spectroscopy of dense coherent media. C1 Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Max Planck Inst Quantenopt, D-85748 Garching, Germany. Natl Inst Stand & Technol, Boulder, CO 80303 USA. Harvard Smithsonian Ctr Astrophys, ITAMP, Cambridge, MA 02138 USA. Lake Forest Coll, Dept Phys, Lake Forest, IL 60045 USA. RP Kash, MM (reprint author), Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. RI Sautenkov, Vladimir/N-7024-2013; Fry, Edward/B-6012-2016; Zibrov, Alexander/G-7419-2014 OI Sautenkov, Vladimir/0000-0001-8400-9405; NR 16 TC 963 Z9 988 U1 3 U2 44 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 28 PY 1999 VL 82 IS 26 BP 5229 EP 5232 DI 10.1103/PhysRevLett.82.5229 PG 4 WC Physics, Multidisciplinary SC Physics GA 211GN UT WOS:000081152700013 ER PT J AU Somaroo, S Tseng, CH Havel, TF Laflamme, R Cory, DG AF Somaroo, S Tseng, CH Havel, TF Laflamme, R Cory, DG TI Quantum simulations on a quantum computer SO PHYSICAL REVIEW LETTERS LA English DT Article ID ERROR-CORRECTION; COMPUTATION; UNIVERSAL; GATES AB We present a general scheme for performing a simulation of the dynamics of one quantum system using another. This scheme is used to experimentally simulate the dynamics of truncated quantum harmonic and anharmonic oscillators using nuclear magnetic resonance. We believe this to be the first explicit physical realization of such a simulation. C1 MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. Harvard Univ, Sch Med, BCMP, Boston, MA 02115 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87455 USA. RP Cory, DG (reprint author), MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. NR 17 TC 106 Z9 110 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 28 PY 1999 VL 82 IS 26 BP 5381 EP 5384 DI 10.1103/PhysRevLett.82.5381 PG 4 WC Physics, Multidisciplinary SC Physics GA 211GN UT WOS:000081152700051 ER PT J AU Harmon, JK Arvidson, RE Guinness, EA Campbell, BA Slade, MA AF Harmon, JK Arvidson, RE Guinness, EA Campbell, BA Slade, MA TI Mars mapping with delay-Doppler radar SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID POLAR ANOMALIES; MERCURY RADAR; ICE; GANYMEDE; CALLISTO; IMAGES; REGION; BACKSCATTER; TOPOGRAPHY; SATELLITES AB Mars radar imaging results from Arecibo 12.6-cm observations are presented. The images were derived from delay-Doppler mapping using a coded-long-pulse technique to mitigate the effects of echo overspreading. Images of the depolarized echo are used to identify regions of high decimeter-scale roughness. Some of the strongest echo features are located on the major shield volcanoes or on relatively young off-shield flows such as the Olympus and Pavonis lava aprons. The shields themselves have highly irregular radar signatures suggesting complex volcanic histories. Some Mars radar features have twice the depolarized brightness of the roughest terrestrial lava flows, apparently due to higher levels of multiple scattering from surfaces of spectacular roughness or from volume scattering. Low-brightness (smooth) areas are associated with older surfaces such as fractured and highland terra, as well as with terrain interpreted to be debris lobes, ash flows, and aureoles; in particular, a close connection was found between the 12.6-cm counterpart of the "Stealth" feature and the Medusae Fossae Formation (postulated to be deep ignimbrite deposits). Marte Vallis is anomalous in being the only outflow channel showing strongly enhanced echoes, which supports the idea that this channel and the Elysium Basin that it drained are filled with lava flows. A weak radar feature was found for the south polar residual ice cap. Comparisons with Goldstone 3.5-cm data show that the south polar enhancement is much weaker at 12.6 cm than at 3.5 cm, indicating that the southern ice cap becomes optically thin at the longer wavelength. A north polar enhancement has also been found, which is comparable in strength to the 12.6-cm south polar feature. C1 Natl Astron & Ionosphere Ctr, Arecibo Observ, Arecibo, PR 00612 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Smithsonian Inst, Natl Air & Space Museum, Washington, DC 20560 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Harmon, JK (reprint author), Natl Astron & Ionosphere Ctr, Arecibo Observ, HC3 Box 53995, Arecibo, PR 00612 USA. NR 53 TC 41 Z9 42 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD JUN 25 PY 1999 VL 104 IS E6 BP 14065 EP 14089 DI 10.1029/1998JE900042 PG 25 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 211DE UT WOS:000081144000004 ER PT J AU Wilf, P Labandeira, CC AF Wilf, P Labandeira, CC TI Response of plant-insect associations to Paleocene-Eocene warming SO SCIENCE LA English DT Article ID PHYTOPHAGOUS ARTHROPOD FAUNA; ELEVATED ATMOSPHERIC CO2; TROPICAL FORESTS; DECIDUOUS TREES; UPPER FRANKONIA; ALDERS ALNUS; HERBIVORY; GROWTH; PALATABILITY; COMMUNITIES AB The diversity of modern herbivorous insects and their pressure on plant hosts generally increase with decreasing Latitude. These observations imply that the diversity and intensity of herbivory should increase with rising temperatures at constant Latitude. Insect damage on fossil Leaves found in southwestern Wyoming, from the Late Paleocene-early Eocene global warming interval, demonstrates this prediction. Early Eocene plants had more types of insect damage per host species and higher attack frequencies than Late Paleocene plants. Herbivory was most elevated on the most abundant group, the birch family (Betulaceae). Change in the composition of the herbivore fauna during the Paleocene-Eocene interval is also indicated. C1 Smithsonian Inst, Natl Museum Amer Hist, Dept Paleobiol, Washington, DC 20560 USA. Univ Maryland, Dept Entomol, College Pk, MD 20742 USA. RP Wilf, P (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Dept Paleobiol, Washington, DC 20560 USA. NR 49 TC 128 Z9 135 U1 7 U2 43 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUN 25 PY 1999 VL 284 IS 5423 BP 2153 EP 2156 DI 10.1126/science.284.5423.2153 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 210HP UT WOS:000081099300044 ER PT J AU Newman, MEJ Eble, GJ AF Newman, MEJ Eble, GJ TI Power spectra of extinction in the fossil record SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE extinction; fossil record; power spectra; Fourier analysis ID STATISTICS AB Recent Fourier analyses of fossil extinction data have indicated that the power spectrum of extinction during the Phanerozoic may take the form of 1/f noise, a result which, it has been suggested, could be indicative of the presence of 'critical dynamics' in the processes giving rise to extinction. In this paper we examine extinction power spectra in some detail, using family-level data from two widely available compilations. We find that although the average form of the power spectrum roughly obeys the 1/f lay the spectrum can be represented more accurately by dividing it into two regimes: a low-frequency one which is well fit by an exponential, and a high-frequency one in which it follows a power law with a 1/f(2) form. We give explanations for the occurrence of each of these behaviours and for the position of the crossover between them. C1 Santa Fe Inst, Santa Fe, NM 87501 USA. Smithsonian Inst, Dept Paleobiol, Washington, DC 20560 USA. RP Newman, MEJ (reprint author), Santa Fe Inst, 1399 Hyde Pk Rd, Santa Fe, NM 87501 USA. NR 10 TC 28 Z9 28 U1 1 U2 5 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD JUN 22 PY 1999 VL 266 IS 1425 BP 1267 EP 1270 PG 4 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA 211HU UT WOS:000081155500011 ER PT J AU Zhang, XL AF Zhang, XL TI Secular evolution of spiral galaxies. III. The Hubble sequence as a temporal evolution sequence SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : fundamental parameters; galaxies : structure ID BUTCHER-OEMLER CLUSTERS; ELLIPTICAL GALAXIES; BARRED GALAXIES; 3-DIMENSIONAL DISTRIBUTION; LUMINOSITY PROFILES; DYNAMICAL EVOLUTION; VELOCITY-DISPERSION; SOLAR NEIGHBORHOOD; STELLAR KINEMATICS; SURFACE PHOTOMETRY AB In the first two papers in this series, we have presented a dynamical mechanism by which an unstable spiral mode in a galactic disk can remain quasi-stationary on the order of a Hubble time at the expense of a continuous dissipative basic state evolution, manifesting as the secular redistribution of disk matter, as well as the secular heating of disk stars. In the current paper, we consider in detail the astrophysical consequences of this spiral-induced basic state evolution process and show that it could explain, among a spectrum of observational facts, the variation of the disk surface-density profiles across the Hubble types, as well as the well-known age-velocity dispersion relation of the solar-neighborhood stars. We seek to establish that the Hubble sequence for the classification of galaxies, when viewed in the reverse direction, is essentially a temporal evolution sequence. The spiral-induced secular mass redistribution process could lead to the evolution of the Hubble type of a spiral galaxy from late (Sd and Sc) to early (Sb and Sa). Furthermore, since similar radial mass-accretion processes could also be mediated by central stellar bars, or other central nonaxisymmetric structures, this leads to the continued galaxy evolution across Hubble type S0 and into disky elliptical galaxies. The secular evolution mechanism presented in this series of papers, together with other previously proposed evolution mechanisms, provides a framework for understanding the results of Hubble Space Telescope Deep Field and Medium Deep Survey, which showed that there is significant evolution of the number statistics of the Hubble types of galaxies with redshift, consistent with an evolution along the Hubble sequence from late to early. It also provides possible solutions to several long-standing problems in the theory and observation of galaxy formation and evolution, among them the cause of the steepening of the galaxy morphology-environment relation; the similarity between the Tully-Fisher and Faber-Jackson relations for spiral and elliptical galaxies, respectively; the existence of a fundamental-plane relation for elliptical galaxies; and the mass-angular momentum anticorrelation observed along the Hubble sequence. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Zhang, XL (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,Mail Stop 78, Cambridge, MA 02138 USA. NR 90 TC 31 Z9 31 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1999 VL 518 IS 2 BP 613 EP 626 DI 10.1086/307287 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211KA UT WOS:000081158700008 ER PT J AU Quillen, AC Rieke, GH Rieke, MJ Caldwell, N Engelbracht, CW AF Quillen, AC Rieke, GH Rieke, MJ Caldwell, N Engelbracht, CW TI Mid-infrared emission from E plus A galaxies in the Coma Cluster SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (Coma); galaxies : stellar content; infrared : galaxies ID IRAS OBSERVATIONS; OPTICAL IDENTIFICATIONS; LUMINOSITY FUNCTIONS; IMMEDIATE VICINITY; RADIO OBSERVATIONS; DISTANT CLUSTERS; STAR-FORMATION; RICH CLUSTERS; EVOLUTION; SPECTROSCOPY AB We have used ISO to observe at 12 mu m seven E + A galaxies plus an additional emission-line galaxy, all in the Coma Cluster. E + A galaxies lacking narrow emission lines have 2.2-12 mu m flux density ratios or limits similar to old stellar populations (typical of early-type galaxies). Only galaxies with emission lines have enhanced 12 mu m flux density. Excess 12 mu m emission is therefore correlated with the presence of ongoing star formation or an active galactic nucleus (AGN). From the mid- and far-infrared colors of the brightest galaxy in our sample, which was detected at longer wavelengths with IR IS, we estimate the far-infrared luminosity of these galaxies. By comparing the current star formation rates with previous rates estimated from the Balmer absorption features, we divide the galaxies into two groups: those for which star formation has declined significantly following a dramatic peak similar to 1 Gyr ago; and those with a significant level of ongoing star formation or/and an AGN. There is no strong difference in the spatial distribution on the sky between these two groups. However, the first group has systemic velocities above the mean cluster value and the second group has systemic velocities below that value. This suggests that the two groups differ kinematically. Based on surveys of the Coma Cluster in the radio, the IRAS sources, and galaxies detected in Ha emission, we sum the far-infrared luminosity function of galaxies in the cluster. We find that star formation in late-type galaxies is probably the dominant component of the Coma Cluster far-infrared luminosity. The presence of significant emission from intracluster dust is not yet firmly established. The member galaxies also account for most of the far-infrared output from nearby rich clusters in general. We update estimates of the far-infrared luminosities of nearby, rich clusters and show that such clusters are likely to undergo luminosity evolution from z = 0.4 at a rate similar to, or faster than, field galaxies. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Smithsonian Inst, FL Whipple Observ, Amado, AZ 85645 USA. RP Quillen, AC (reprint author), Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. NR 48 TC 18 Z9 18 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1999 VL 518 IS 2 BP 632 EP 640 DI 10.1086/307307 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211KA UT WOS:000081158700010 ER PT J AU Quinn, J Bond, IH Boyle, PJ Bradbury, SM Breslin, AC Buckley, JH Burdett, AM Gordo, JB Carter-Lewis, DA Catanese, M Cawley, MF Fegan, DJ Finley, JP Gaidos, JA Hall, T Hillas, AM Krennrich, F Lamb, RC Lessard, RW Masterson, C McEnery, JE Moriarty, P Rodgers, AJ Rose, HJ Samuelson, FW Sembroski, GH Srinivasan, R Vassiliev, VV Weekes, TC AF Quinn, J Bond, IH Boyle, PJ Bradbury, SM Breslin, AC Buckley, JH Burdett, AM Gordo, JB Carter-Lewis, DA Catanese, M Cawley, MF Fegan, DJ Finley, JP Gaidos, JA Hall, T Hillas, AM Krennrich, F Lamb, RC Lessard, RW Masterson, C McEnery, JE Moriarty, P Rodgers, AJ Rose, HJ Samuelson, FW Sembroski, GH Srinivasan, R Vassiliev, VV Weekes, TC TI The flux variability of Markarian 501 in very high energy gamma rays SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : individual (Markarian 501); gamma rays : observations ID ACTIVE GALAXY MARKARIAN-421; TEV PHOTONS; EMISSION AB The BL Lacertae object Markarian 501 was identified as a source of gamma-ray emission at the Whipple Observatory in 1995 March. Here we present a flux variability analysis on several timescales of the 233 hr data set accumulated over 213 nights (from March 1995 to July 1998) with the Whipple Observatory 10 m atmospheric Cerenkov imaging telescope. In 1995, with the exception of a single night, the flux from Markarian 501 was constant on daily and monthly timescales and had an average flux of only 10% that of the Crab Nebula, making it the weakest very high energy source detected to date. In 1996, the average flux was approximately twice the 1995 flux and showed significant month-to-month variability. No significant day-scale variations were detected. The average gamma-ray flux above similar to 350 GeV in the 1997 observing season rose to 1.4 times that of the Crab Nebula-14 times the 1995 discovery level-allowing a search for variability on timescales shorter than 1 day. Significant hour-scale variability was present in the 1997 data, with the shortest, observed on MJD 50,607, having a doubling time of similar to 2 hr. In 1998 the average emission level decreased considerably from that of 1997 (to similar to 20% of the Crab Nebula flux), but two significant flaring events were observed. Thus the emission from Markarian 501 shows large amplitude and rapid flux variability at very high energies, as does Markarian 421. It also shows large mean flux level variations on year-to-year timescales, behavior that has not been seen from Markarian 421 so far. C1 Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA. Natl Univ Ireland Univ Coll Dublin, Dept Expt Phys, Dublin 4, Ireland. Univ Leeds, Dept Phys, Leeds LS2 9JT, W Yorkshire, England. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Natl Univ Ireland, Dept Phys, Maynooth, Kildare, Ireland. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. Galway Mayo Inst Technol, Dept Phys Sci, Galway, Ireland. RP Quinn, J (reprint author), Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, POB 97, Amado, AZ 85645 USA. NR 26 TC 39 Z9 39 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1999 VL 518 IS 2 BP 693 EP 698 DI 10.1086/307329 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211KA UT WOS:000081158700015 ER PT J AU Bell, MB Feldman, PA Watson, JKG McCarthy, MC Travers, MJ Gottlieb, CA Thaddeus, P AF Bell, MB Feldman, PA Watson, JKG McCarthy, MC Travers, MJ Gottlieb, CA Thaddeus, P TI Observations of long CnH molecules in the dust cloud TMC-1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; radio lines : ISM ID DENSE INTERSTELLAR CLOUDS; NEUTRAL-NEUTRAL REACTIONS; HYPERFINE-STRUCTURE; C6H; IRC+10216; RADICALS; TAURUS; C4H AB We report detection of the J = 15.5-14.5 and 17.5-16.5 transitions of C8H, a sensitive upper limit for the J = 10.5-9.5 transition of C7H, and measurements of two low-frequency transitions of C6H in TMC-1. These results give new information on the relative abundances of long carbon-chain radicals in TMC-1 and confirm the recent laboratory-measured hyperfine-splitting constants of C6H. We compare our results with the recent early-time, gas-phase chemistry model of Herbst and Terzieva and with that of Millar and coworkers. We find the abundance ratios in the longer CnH chains decline much more rapidly than found for the longer HCnN chains. Although the decrease in fractional abundance with increasing chain length from C4H to C8H is reasonably well reproduced by the models of Herbst and Terzieva, C8H is observationally somewhat underabundant compared to these calculations. Although we searched for the J = 7.5-6.5 and J = 10.5-9.5 transitions of C7H, nearby interference in the case of the higher transition and possible confusion with nearby U-lines prevent us from claiming a detection. However, we are able to report an upper limit to the abundance of C7H in TMC-1 that is at least a factor of 20 below that of C5H. The steep fall-off in abundance for the longer CnH molecules, also found in IRC+10216 by Gut lin and coworkers, suggests that the likelihood is small that a large fraction of carbon is locked up in long CnH chains in dense dark clouds like TMC-1. If long CnH chains are not present in high abundance in either dark clouds or the envelopes of carbon stars, the possibility that they are present in abundance in the diffuse gas also appears less likely. The cyanopolyynes, which have been detected at relatively high abundances to and including HC11N, may then be the most abundant carbon-chain molecules in the diffuse gas. These observations and our earlier observations of HC9N in TMC-1 have allowed us to estimate the line density at a level of T-A*similar to 1 mK in this dust cloud to be 0.9 lines MHz(-1). C1 Natl Res Council Canada, Herzberg Inst Astrophys, Ottawa, ON K1A 0R6, Canada. Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V8X 4M6, Canada. Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Natl Res Council Canada, Herzberg Inst Astrophys, 100 Sussex Dr, Ottawa, ON K1A 0R6, Canada. OI McCarthy, Michael/0000-0001-9142-0008 NR 29 TC 59 Z9 60 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1999 VL 518 IS 2 BP 740 EP 747 DI 10.1086/307303 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211KA UT WOS:000081158700018 ER PT J AU Laming, JM Feldman, U Drake, JJ Lemaire, P AF Laming, JM Feldman, U Drake, JJ Lemaire, P TI The off-limb behavior of the first ionization potential effect in T > 5 x 10(5) K solar plasmas SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : abundances; Sun : corona; Sun : transition region; Sun : UV radiation ID STELLAR CORONAL ABUNDANCES; UNRESOLVED FINE-STRUCTURES; ELEMENTAL ABUNDANCES; TEMPERATURE REGION; TRANSITION REGION; SUMER TELESCOPE; ATMOSPHERE; SPECTRA; SOHO; SPECTROMETER AB We investigate the behavior of the solar first ionization potential (FIP) effect (the abundance enhancement of elements with first ionization potential of less than 10 eV in the corona with respect to photospheric values) with height above the limb in a region of diffuse quiet corona observed by the SUMER instrument on SOHO, with emphasis on so-called upper transition region lines. Previous disk observations have shown different abundance patterns in emission from lines at temperatures above and below similar to 8 x 10(5) K, with an FIP effect clearly visible at the higher temperatures and less so at the lower temperatures. Our initial aim is to determine whether such a difference is also visible in off-limb observations. We find a low-FIP element enhancement of a factor of 3-4 indicated in all line ratios. The Mg vn 868.11/Ne VII 895.17 ratio is also seen to decrease toward a photospheric value when tracked down from the corona to the limb. This is markedly different from the behavior of higher temperature line ratios and may be related to the differing heating and mass supply mechanisms for plasmas at temperatures above and below similar to 8 x 10(5) K. An additional unexpected feature of our observations is that in low-FIP/high-FIP line ratios formed at temperatures close to the freeze-in temperature of the fast solar wind (similar to 10(6) K), there is also a small diminution of the FIP enhancement at the highest altitudes observed in this study. We discuss the possible relevance of this to the origin of the fast solar wind. C1 SFA Inc, Largo, MD 20774 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Smithsonian Astrophys Lab, Cambridge, MA 02138 USA. Univ Paris 11, Inst Astrophys Spatiale, CNRS, F-91405 Orsay, France. RP Laming, JM (reprint author), SFA Inc, Largo, MD 20774 USA. NR 34 TC 13 Z9 13 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1999 VL 518 IS 2 BP 926 EP 936 DI 10.1086/307294 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211KA UT WOS:000081158700036 ER PT J AU Cranmer, SR Field, GB Kohl, JL AF Cranmer, SR Field, GB Kohl, JL TI Spectroscopic constraints on models of ion cyclotron resonance heating in the polar solar corona and high-speed solar wind SO ASTROPHYSICAL JOURNAL LA English DT Review DE line : profiles; plasmas; solar wind; Sun : corona; Sun : UV radiation; waves ID INTERPLANETARY MAGNETIC-FIELD; ALFVEN WAVES; TRANSPORT-EQUATIONS; MAGNETOHYDRODYNAMIC TURBULENCE; VELOCITY DISTRIBUTIONS; SUMER TELESCOPE; HEAVY-IONS; ACCELERATION; PLASMA; SOHO AB Using empirical ion velocity distributions derived from Ultraviolet Coronagraph Spectrometer (UVCS) and Solar Ultraviolet Measurements of Emitted Radiation (SUMER) ultraviolet spectroscopy, we construct theoretical models of the nonequilibrium plasma state of the polar solar corona. The primary energy deposition mechanism we investigate is the dissipation of high-frequency (10-10,000 Hz) ion cyclotron resonant Alfven waves which can heat and accelerate ions differently depending on their charge and mass. We solve the internal energy conservation equations for the ion temperature components parallel and perpendicular to the superradially expanding magnetic field lines and use empirical constraints for the remaining parameters. We find that it is possible to explain many of the kinetic properties of the plasma (such as high perpendicular ion temperatures and strong temperature anisotropies) with relatively small amplitudes for the resonant waves. There is suggestive evidence for steepening of the Alfven wave spectrum between the coronal base and the largest heights observed spectroscopically, and it is important to take Coulomb collisions into account to understand observations at the lowest heights. Because the ion cyclotron wave dissipation is rapid, the extended heating seems to demand a constantly replenished population of waves over several solar radii. This indicates that the waves are generated gradually throughout the wind rather than propagated up from the base of the corona. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Cranmer, SR (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 108 TC 224 Z9 226 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1999 VL 518 IS 2 BP 937 EP 947 DI 10.1086/307330 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211KA UT WOS:000081158700037 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI What is painting?: Representation and modern art. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Lib, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD JUN 15 PY 1999 VL 124 IS 11 BP 73 EP 73 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 208LK UT WOS:000080992400033 ER PT J AU Harasewych, MG Kantor, YI AF Harasewych, MG Kantor, YI TI A revision of the antarctic genus Chlanidota (Gastropoda : Neogastropoda : Buccinulidae) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB The genus Chlanidota is revised to contain two subgenera, Chlanidota sensu stricto and Chlanidota (Pfefferia). Chlanidota s.s. has a broad distribution throughout the Antarctic region, and contains five species: Chlanidota (Chlanidota) vestita (Martens, 1881), C. (C.) densesculpta (Martens, 1885), C. (C.) paucispiralis Powell, 1951, C. (C.) pilosa Powell, 1951, and C. (C.) signeyana Powell, 1951. The subgenus Pfefferia, which differs from Chlanidota primarily in the morphology of its operculum, is endemic to South Georgia Island, and is known from three species: Chlanidota (Pfefferia) chordata (Strebel, 1908), C. (P.) palliata (Strebel, 1908), C. (P.) invenusta, new species. With its bulliform shell lacking a siphonal canal, the monotypic, circum-Antarctic genus Neobuccinum is conjectured to be the sister taxon of Chlanidota, but is readily distinguished by its smoother, higher-spired shell, radula in which the central cusp of the lateral teeth is medially placed, and a penis lacking a papilla. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. Russian Acad Sci, Severtsov Inst, Moscow 117071, Russia. RP Harasewych, MG (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RI Kantor, Yuri/D-5259-2014 OI Kantor, Yuri/0000-0002-3209-4940 NR 63 TC 12 Z9 14 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUN 15 PY 1999 VL 112 IS 2 BP 253 EP 302 PG 50 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 209KC UT WOS:000081045900001 ER PT J AU Malabarba, LR Weitzman, SH AF Malabarba, LR Weitzman, SH TI A new genus and species of South American fishes (Teleostei : Characidae : Cheirodontinae) with a derived caudal fin, including comments about inseminating cheirodontines SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID GLANDULOCAUDINAE AB Acinocheriodon melanogramma from tributaries of the rio Sao Francisco and the rio Jequitinhonha, Minas Gerais, Brazil, is described as a new genus and species of inseminating cheirodontines. The adult males are distinguished by possession of modified thirteenth to fifteenth, ventral caudalfin rays bearing dorsally directed hooks surrounded by fleshy, possibly glandular, structures. These structures appear similar to, but are here hypothesized as convergent with some of the derived caudal glandular organs of certain glandulocaudine characids and the species of the incertae sedis characid genus Brittanichthys. Putative relationships of these taxa to the new genus are explored and rejected. The new species is referred to the Cheirodontinae on the basis of a cladistic diagnosis of this subfamily. Hypotheses of relationships with other inseminating cheirodontines bearing modified caudal fins are explored. C1 Pontificia Univ Catolica do Rio Grande do Sul, Museo Ciencias & Tecnol, Lab Ictiol, BR-90619900 Porto Alegre, RS, Brazil. Univ Fed Rio Grande Sul, Inst Biociencias, Dept Zool, BR-90049 Porto Alegre, RS, Brazil. Smithsonian Inst, Dept Vertebrate Zool, Div Fishes, MRC 159, Washington, DC 20560 USA. RP Malabarba, LR (reprint author), Pontificia Univ Catolica do Rio Grande do Sul, Museo Ciencias & Tecnol, Lab Ictiol, Av Ipiranga 6681, BR-90619900 Porto Alegre, RS, Brazil. RI Malabarba, Luiz/I-3225-2012 NR 43 TC 20 Z9 20 U1 0 U2 1 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUN 15 PY 1999 VL 112 IS 2 BP 410 EP 432 PG 23 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 209KC UT WOS:000081045900013 ER PT J AU Smith, DG Baldwin, CC AF Smith, DG Baldwin, CC TI Psilotris amblyrhynchus, a new seven-spined goby (Teleostei : Gobiidae) from Belize, with notes on settlement-stage larvae SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID WESTERN ATLANTIC; PISCES AB Psilotris amblyrhynchus is described from one adult and one juvenile collected in shallow waters in the vicinity of Carrie Bow Gay, Belize, Central America. Settlement-stage larvae of the new species were collected in a stationary plankton net and are used to augment the description; two of these were reared through metamorphosis. Psilotris amblyrhynchus is distinguished from other western Atlantic seven-spined gobies on the basis of meristic features and pigment pattern. Psilotris is one of 15 genera assigned by Birdsong et al. (1988) to the "Gobiosoma group," but the genus is not defined on the basis of derived characters. Assignment of the new species to Psilotris is based on its having separate pelvic fins, seven spines in the first dorsal fin, no scales, and no head pores. None of these characters by itself is unique within the Gobiosoma group to Psilotris, and the configuration of the pelvic fins is highly variable among gobies. Our inability to diagnose Psilotris cladistically, along with our discovery of resemblances between larvae of Psilotris amblyrhynchus and those of another western Atlantic member of the Gobiosoma group, Nes longus, suggest that generic concepts within the Gobiosoma group should be reassessed. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, MRC 159, Washington, DC 20560 USA. RP Smith, DG (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, MRC 159, Washington, DC 20560 USA. NR 10 TC 7 Z9 8 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUN 15 PY 1999 VL 112 IS 2 BP 433 EP 442 PG 10 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 209KC UT WOS:000081045900014 ER PT J AU Graves, GR AF Graves, GR TI Diagnoses of hybrid hummingbirds (Aves : Trochilidae). 7. Probable parentage of Calliphlox iridescens Gould, 1860 SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID INTERGENERIC HYBRID AB Calliphlox iridescens Gould, 1860 is hypothesized to be a hybrid between Calliphlox amethystina and Chlorostilbon aureoventris. The hybrid, collected at Nova Friburgo, Rio de Janeiro, Brazil, exhibits a blended mosaic of plumage characters of the presumed parental species. External measurements of the hybrid fall between the character means of the parental species and approach the values expected from least squares regression of parental measurements. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. RP Graves, GR (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. NR 22 TC 2 Z9 2 U1 0 U2 1 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUN 15 PY 1999 VL 112 IS 2 BP 443 EP 450 PG 8 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 209KC UT WOS:000081045900015 ER PT J AU Laurance, WF Fearnside, PM Laurance, SG Delamonica, P Lovejoy, TE Rankin-de Merona, J Chambers, JQ Gascon, C AF Laurance, WF Fearnside, PM Laurance, SG Delamonica, P Lovejoy, TE Rankin-de Merona, J Chambers, JQ Gascon, C TI Relationship between soils and Amazon forest biomass: A landscape-scale study SO FOREST ECOLOGY AND MANAGEMENT LA English DT Article DE Amazon basin; biomass; carbon cycle; ferralsols; global warming; pasture conversion; soils; terra-firme forests; tropical rainforests ID TROPICAL RAIN-FOREST; TREE SPECIES RICHNESS; BRAZILIAN AMAZONIA; GREENHOUSE GASES; LAND-USE; CARBON; DEFORESTATION; VEGETATION; NUTRIENTS; PATTERNS AB Above-ground dry biomass of living trees including palms was estimated in 65 l ha plots spanning a 1000 km(2) landscape in central Amazonia. The study area was located on heavily weathered, nutrient-poor soils that are widespread in the Amazon region. Biomass values were derived by measuring the diameter-at-breast-height (DBH) of all greater than or equal to 10 cm trees in each plot, then using an allometric equation and correction factor for small trees to estimate total tree biomass. Detailed information on soil texture, organic carbon, available water capacity, pH, macro- and micro-nutrients, and trace elements was collected from soil surface samples (0-20 cm) in each plot, while slope was measured with a clinometer. Biomass estimates varied more than two-fold, from 231 to 492 metric tons ha(-1), with a mean of 356 +/- 47 tons ha(-1). Simple correlations with stringent (p < 0.006) Bonferroni corrections suggested that biomass was positively associated with total N, total exchangeable bases, K+, Mg2+, clay, and organic C in soils, and negatively associated with Zn+, aluminum saturation, and sand. An ordination analysis revealed one major and several minor soil gradients in the study area, with the main gradient discriminating sites with varying proportions of clay (with clayey soils having higher concentrations of total N, organic C, most cations, and lower aluminum saturation and less sand). A multiple regression analysis revealed that the major clay-nutrient gradient was the only significant predictor, with the model explaining 32.3% of the total variation in biomass. Results of the analysis suggest that soil-fertility parameters can account for a third or more of the variation in above-ground biomass in Amazonian terra-firme forests. We suggest that, because the conversion of forest to pasture tends to reduce the nitrogen, clay, organic carbon, and nutrient contents of soils, forests that regenerate on formerly cleared lands may have lower biomass than the original forest, especially in areas with low soil fertility. (C) 1999 Elsevier Science B.V. All rights reserved. C1 INPA, Natl Inst Res Amazon, Biol Dynam Forest Fragments Project, BR-69011970 Manaus, Amazonas, Brazil. INPA, Natl Inst Res Amazon, Dept Ecol, BR-69011970 Manaus, Amazonas, Brazil. Smithsonian Inst, Washington, DC 20036 USA. Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA. RP Laurance, WF (reprint author), INPA, Natl Inst Res Amazon, Biol Dynam Forest Fragments Project, CP 478, BR-69011970 Manaus, Amazonas, Brazil. EM wfl@inpa.gov.br RI Laurance, William/B-2709-2012; Fearnside, Philip/D-6559-2011; Chambers, Jeffrey/J-9021-2014; Laurance, Susan/G-6021-2011 OI Fearnside, Philip/0000-0003-3672-9082; Chambers, Jeffrey/0000-0003-3983-7847; Laurance, Susan/0000-0002-2831-2933 NR 78 TC 204 Z9 228 U1 12 U2 86 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1127 J9 FOREST ECOL MANAG JI For. Ecol. Manage. PD JUN 14 PY 1999 VL 118 IS 1-3 BP 127 EP 138 DI 10.1016/S0378-1127(98)00494-0 PG 12 WC Forestry SC Forestry GA 183PK UT WOS:000079561800012 ER PT J AU Mahdavi, A Geller, MJ Bohringer, H Kurtz, MJ Ramella, M AF Mahdavi, A Geller, MJ Bohringer, H Kurtz, MJ Ramella, M TI The dynamics of poor systems of galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : general; galaxies : fundamental parameters; X-rays : galaxies ID SKY REDSHIFT SURVEY; X-RAY-EMISSION; COMPACT-GROUPS; LOOSE GROUPS; DARK-MATTER; CLUSTERS; EVOLUTION; VELOCITIES; MORPHOLOGY; ALGORITHMS AB We assemble and observe a sample of poor galaxy systems that is suitable for testing N-body simulations of hierarchical clustering and other dynamical halo models. We (1) determine the parameters of the density profile rho(r) and the velocity dispersion profile sigma(p)(R), (2) separate emission-line galaxies from absorption-line galaxies, examining the model parameters and as a function of spectroscopic type, and (3) for the best-behaved subsample, constrain the velocity anisotropy parameter, beta, which determines the shapes of the galaxy orbits. Our sample consists of 20 systems, 12 of which have extended X-ray emission in the ROSAT All-Sky Survey. We measure the 877 optical spectra of galaxies brighter than m(R) approximate to 15.4 within 1.5 h(-1) Mpc of the system centers (we take H-0 = 100 h km s(-1) Mpc(-1)). Thus, we sample the system membership to a radius typically three times larger than other recent optical group surveys. The average system population is 30 galaxies, and the average line-of-sight velocity dispersion is approximate to 300 km s(-1). The Navarro, Frenk, & White universal profile and the Hernquist model both provide good descriptions of the spatial data. In most cases an isothermal sphere is ruled out. Systems with declining sigma(p)(R) are well-matched by theoretical profiles in which the star-forming galaxies have predominantly radial orbits (beta > 0); many of these galaxies are probably falling in for the first time. There is significant evidence for spatial segregation of the spectroscopic classes regardless of sigma(p)(R). C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Max Planck Inst Extraterr Phys, Garching, Germany. Osserv Astron Trieste, I-34131 Trieste, Italy. RP Mahdavi, A (reprint author), Harvard Smithsonian Ctr Astrophys, Mail Stop 10,60 Garden St, Cambridge, MA 02138 USA. RI KURTZ, Michael /B-3890-2009; OI Kurtz, Michael/0000-0002-6949-0090 NR 73 TC 60 Z9 61 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP 69 EP 93 DI 10.1086/307280 PN 1 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211JZ UT WOS:000081158600007 ER PT J AU Haiman, Z Spaans, M AF Haiman, Z Spaans, M TI Models for dusty Ly alpha emitters at high redshift SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : ISM; galaxies : stellar content; stars : formation; ultraviolet : galaxies ID RESONANCE-LINE RADIATION; STAR-FORMING GALAXIES; GUNN-PETERSON TROUGH; PRIMEVAL GALAXIES; COSMOLOGICAL CONSTANT; INTERGALACTIC MEDIUM; DISK GALAXIES; REIONIZATION; EMISSION; UNIVERSE AB Models are presented for the Ly alpha emission of dusty high-redshift galaxies by combining the Press-Schechter formalism with a treatment of the inhomogeneous dust distribution inside galaxies. It is found that the amount of Ly alpha radiation escaping from the galaxies strongly depends on the time over which the dust is produced through stellar activity and on the ambient inhomogeneity of the H II regions that surround the ionizing OB stars. Good agreement is found with recent observations, as well as with previous nondetections. Although a detailed determination of the individual model parameters is precluded by uncertainties, we find that (1) the dust content in primordial galaxies builds up in no more than similar to 5 x 10(8) yr, (2) the galactic H II regions are inhomogeneous with a cloud-covering factor of order unity, and (3) the overall star formation efficiency is at least similar to 5%. It is predicted that future observations can detect these Ly alpha galaxies up to redshifts of similar to 8. If the universe is reionized at z(r) less than or similar to 8, the corresponding decline in the number of Ly alpha emitters at z greater than or similar to z(r) could prove to be a useful probe of the reionization epoch. C1 NASA, Fermilab Astrophys Grp, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Haiman, Z (reprint author), NASA, Fermilab Astrophys Grp, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. NR 59 TC 108 Z9 108 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP 138 EP 144 DI 10.1086/307276 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211JZ UT WOS:000081158600012 ER PT J AU Colley, WN Schild, RE AF Colley, WN Schild, RE TI Precision photometry for Q0957+561 images A and B SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; galaxies : halos; gravitational lensing; methods : data analysis; quasars : individual (0957+561); techniques : photometric ID TWIN QSO Q0957+561; GRAVITATIONAL LENS; TIME-DELAY; QUASAR Q0957+561; 0957+561A; SYSTEMS; STARS AB Since the persuasive determination of the time delay in Q0957+561, much interest has centered around shifting and subtracting the A and B light curves to look for residuals due to microlensing. Solar mass objects in the lens galaxy produce variations on timescales of decades, with amplitudes of a few tenths of a magnitude, but MACHOs (with masses of order 10(-3)-10(-7) M.) produce variations at only the 5% level. To detect such small variations, highly precise photometry is required. To that end, we have used 150 observations over three nights to examine the effects of seeing on the light curves. We have determined that seeing itself can be responsible for correlated 5% variations in the light curves of A and B, which could masquerade as microlensing events. We have found, however, that these effects can be accurately removed by subtracting the light from the lens galaxy and by correcting for cross contamination of light between the closely juxtaposed A and B images. We find that these corrections improve the variations due to seeing from 5% to a level on the order of the photon shot noise (0.5%). We also find that this corrected aperture photometry method is more reliable at removing the errors due to seeing than is a direct implementation of point-spread function fitting photometry. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Colley, WN (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 23 TC 11 Z9 11 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP 153 EP 166 DI 10.1086/307266 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211JZ UT WOS:000081158600014 ER PT J AU McNamara, BR Jannuzi, BT Sarazin, CL Elston, R Wise, M AF McNamara, BR Jannuzi, BT Sarazin, CL Elston, R Wise, M TI An alignment effect in FR I radio galaxies: U-band polarimetry of the Abell 2597 cluster central galaxy SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : clusters : individual (A2597); polarization ID ACTIVE GALACTIC NUCLEI; BL LACERTAE OBJECTS; STAR-FORMATION; COOLING FLOWS; REDSHIFT; EMISSION; SCATTERING; CONTINUUM; ORIGIN; 3C-256 AB We have obtained U-band polarimetry of the spatially extended blue optical continuum associated with the FR I radio source PKS 2322-122, located in the Abell 2597 cluster central galaxy. We find a 3 sigma upper limit to the degree of optical continuum polarization of less than 6%. The accuracy of the measurement is limited primarily by our ability to measure the amount of diluting galactic starlight. This limit is inconsistent with the blue continuum being primarily scattered light or synchrotron radiation. We can therefore exclude models that attribute the blue continuum to scattered light from an active nucleus that is hidden from direct view. Our result does not support the unification paradigm for BL Lac objects and FR I radio sources. Essentially all of the data pertaining to the blue continuum along the radio source-the "blue lobes"-indicate that they are regions of recent star formation. The spatial coincidence between the blue lobes and disturbances in the radio source suggests that star formation may have been induced by an interaction between the radio source and the cool (less than 10(4) K) surrounding gas. This result, in addition to the results of a similar study of the A1795 cluster central galaxy, shows that under the appropriate conditions FR I radio sources may be capable of inducing significant episodes of star formation in elliptical galaxies. We compare the rest-frame U-band polarized luminosities and 1.4 GHz radio powers of A2597 and A1795 to those for several high-redshift radio galaxies exhibiting the alignment effect. We find that if the polarized luminosities of radio galaxies scale in proportion to their radio luminosities, we would not have detected a polarized signal in either A2597 or A1795. We suggest that the strength of the active galactic nucleus is the fundamental property distinguishing some powerful high-redshift radio galaxies exhibiting the alignment effect from the lower power FR I radio galaxies in cooling flows that exhibit the blue lobe phenomenon. While both FR I and FR II radio sources seem to be capable of triggering star formation, FR I radio sources seem to be incapable of producing a large enough polarized luminosity to contribute significantly to the aligned continuum radiation. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. RP McNamara, BR (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 56 TC 10 Z9 10 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP 167 EP 176 DI 10.1086/307262 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211JZ UT WOS:000081158600015 ER PT J AU Keto, E Hora, JL Fazio, GG Hoffmann, W Deutsch, L AF Keto, E Hora, JL Fazio, GG Hoffmann, W Deutsch, L TI A super-star cluster in NGC 253: Mid-infrared properties SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 253); galaxies : starburst; galaxies : star clusters ID PLANETARY CAMERA OBSERVATIONS; SPACE-TELESCOPE OBSERVATIONS; STARBURST GALAXY NGC-253; COMPACT RADIO-SOURCES; H-II REGIONS; GLOBULAR-CLUSTERS; VLA OBSERVATIONS; MICRON EMISSION; NUCLEUS; YOUNG AB We observed the nearby starburst galaxy NGC 253 in the mid-infrared to obtain a three-dimensional data set with arcsecond angular resolution and 0.2 mu m spectral resolution. The observations show the major spectral features in the upper half of the mid-IR window: the 11.3 mu m polycyclic aromatic hydrocarbon (PAH) line and the 12.8 mu m [Ne II] line as well as the broad silicate absorption feature at 9.7 mu m. We use the [Ne II] line to determine the emission measure of the ionized gas, and in combination with radio observations to predict the thermal and nonthermal contributions to the radio continuum. The amount of ionized gas is related to the rate of star formation. Based on the mid-IR spectra, we identify three major components in the nucleus of NGC 243: an AGN in the center of the galaxy, a super-star cluster also seen in optical images, and a larger scale diffuse envelope composed of an older population of supernova remnants and lower mass stars. C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Boston Univ, Dept Astron, Boston, MA 02215 USA. RP Keto, E (reprint author), Smithsonian Astrophys Observ, 60 Garden St, Cambridge, MA 02138 USA. OI Hora, Joseph/0000-0002-5599-4650 NR 54 TC 39 Z9 39 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP 183 EP 189 DI 10.1086/307246 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211JZ UT WOS:000081158600017 ER PT J AU Saito, M Sunada, K Kawabe, R Kitamura, Y Hirano, N AF Saito, M Sunada, K Kawabe, R Kitamura, Y Hirano, N TI The initial conditions for formation of low-mass stars: Kinematics and density structure of the protostellar envelope in B335 SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; ISM : individual (B335); ISM : molecules; stars : formation ID SMALL-SCALE STRUCTURE; MOLECULAR OUTFLOW; BIPOLAR OUTFLOW; DARK CLOUDS; GAS DISK; HL TAURI; CORES; HCO+; DYNAMICS; EMISSION AB We have observed dense molecular gas toward a deeply embedded protostar in B335 using the Nobeyama 45 m telescope and the Nobeyama Millimeter Array. The (HCO+)-C-13 and (CO)-O-18 maps taken by the 45 m telescope show elongated features perpendicular to the axis of molecular outflow, suggesting that these emission lines arise from a dense disklike envelope surrounding the protostar. The size and mass of the (HCO+)-C-13 disklike envelope are 0.17 x 0.15 pc and 2.4 M., respectively. The (CO)-O-18 envelope gas has a linear velocity gradient along its major axis indicative of a rigid rotation with an angular velocity of 1.1 x 10(-14) radians s(-1). The density profile derived from the (CO)-O-18 and (HCO+)-C-13 data shows a power law of rho(r) similar to rho(0)r(-1.95) similar to (a(2)/2 pi G)r(-2) over the radius range between 0.03 and 0.2 pc. Tn addition, the coefficient of the density profile is consistent with Shu's solution rather than Larson's, though there is uncertainty particularly in the fractional abundance of the (HCO+)-C-13 molecule. Our results suggest that the protostar in B335 was formed in an isothermal core with a rigid rotation. The interferometric observations of the (HCO+)-C-13 line reveal a dense compact feature centered on the protostar. This compact feature has a size of 2000 AU, and its elongation is roughly perpendicular to the outflow axis. We thus consider that this compact feature is an inner part of the disklike envelope. There is a velocity gradient along the minor axis of the feature which might be interpreted as a disk infalling motion. The previous observations also suggested the existence of infalling motion toward the protostar B335 IRS. In addition, the inner envelope shows a rotating motion of V-theta = 0.14 km s(-1) at r = 490 AU. This rotational velocity is smaller than the corresponding Keplerian velocity of similar to 0.42 km s(-1), indicating that the inner envelope is not rotationally supported. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Inst Space & Astronaut Sci, Kanagawa 229, Japan. Hitotsubashi Univ, Lab Astron & Geophys, Tokyo 186, Japan. RP Saito, M (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 37 TC 31 Z9 31 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP 334 EP 345 DI 10.1086/307244 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211JZ UT WOS:000081158600028 ER PT J AU Garcia, MR Callanan, PJ McCarthy, J Eriksen, K Hjellming, RM AF Garcia, MR Callanan, PJ McCarthy, J Eriksen, K Hjellming, RM TI Aquila X-1 in outburst and quiescence SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; stars : individual (Aquila X-1); stars : neutron; X-rays : stars ID X-RAY SOURCES; CENTAURUS X-4; NEUTRON-STARS; TRANSIENT; BINARIES; DWARF; MASS; EMISSION; PERIOD; CURVE AB We present photometry and spectroscopy of the soft X-ray transient Aq1 X-1. Optical photometry during an active state shows a strong (0.6 mag peak-to-peak) modulation at a period of 19 hr. Infrared (K' band) photometry during a quiescent state limits any ellipsoidal variations to less than 0.07 mag (peak-to-peak), which implies an inclination i < 31 degrees (90% limit). Spectroscopy in a quiescent state shows at most very small radial velocity variations, which implies a very low inclination of i < 12 degrees (90% limit). The low inclination is rather unexpected given the large photometric modulation seen in the active state. The upper limit to the equivalent width of the anomalous Li 6707 Angstrom line is less than 0.3 Angstrom, which is similar to the measured strength of this line in several other X-ray transients. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Coll, Dept Phys, Cork, Ireland. Natl Radio Astron Observ, Socorro, NM 87801 USA. RP Garcia, MR (reprint author), Harvard Smithsonian Ctr Astrophys, MS-4,60 Garden St, Cambridge, MA 02138 USA. NR 44 TC 19 Z9 19 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP 422 EP 427 DI 10.1086/307283 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211JZ UT WOS:000081158600035 ER PT J AU Fontenla, J White, OR Fox, PA Avrett, EH Kurucz, RL AF Fontenla, J White, OR Fox, PA Avrett, EH Kurucz, RL TI Calculation of solar irradiances. I. Synthesis of the solar spectrum SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : atmosphere; Sun : general; Sun : infrared; Sun : UV radiation ID PHYSICAL-PROPERTIES; MAGNETIC ELEMENTS; MOLECULAR-DATA; MODELS; CHROMOSPHERE; ULTRAVIOLET; OPACITY; LINES; EUV; SPECTROSCOPY AB Variations in the total radiative output of the Sun as well as the detailed spectral irradiance are of interest to terrestrial and solar-stellar atmosphere studies. Recent observations provide measurements of spectral irradiance variations at wavelengths in the range 1100-8650 Angstrom with improved accuracy, and correlative studies give procedures for estimating the spectral irradiance changes from solar activity records using indicators such as those derived from Ca II K and Mg II indices. Here we describe our approach to physical modeling of irradiance variations using seven semiempirical models to represent sunspots, plage, network, and quiet atmosphere. This paper gives methods and details, and some preliminary results of our synthesis of the variations of the entire irradiance spectrum. Our calculation uses object-oriented programming techniques that are very efficient and flexible. We compute at high spectral resolution the intensity as a function of wavelength and position on the disk for each of the structure types corresponding to our models. These calculations include three different approximations for the line source function: one suited for the very strong resonance lines where partial redistribution (PRD) is important, another for the most important nonresonance lines, and another approximation for the many narrow lines that are provided in Kurucz's listings. The image analysis and calculations of the irradiance variation as a function of time will be described in a later paper. This work provides an understanding of the sources of variability arising from solar-activity surface structures. We compute the Ly alpha irradiance to within 3% of the observed values. The difference between our computations and the Neckel & Labs data is 3% or less in the near-TR wavelengths at 8650 Angstrom, and less than 1% in the red at 6080 Angstrom. Near 4100 Angstrom we overestimate the irradiance by 9%-19% because of opacity sources missing in our calculations. We also compute a solar cycle variability of 49% in the Ly alpha irradiance, which is very close to observed values. At wavelengths between 4100 Angstrom and 1.6 mu m, we obtain spectral irradiance variations ranging from -0.06% to 0.46% in the visible-the higher values correspond to the presence of strong lines. The variability in the IR between 1.3 and 2.2 mu m is similar to-0.15%. C1 Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP 771 W Dahlia, Louisville, CO 80027 USA. EM jfontenla@mho.net OI Fox, Peter/0000-0002-1009-7163 NR 71 TC 168 Z9 176 U1 3 U2 9 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP 480 EP 499 DI 10.1086/307258 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211JZ UT WOS:000081158600041 ER PT J AU Nisenson, P Papaliolios, C AF Nisenson, P Papaliolios, C TI A second bright source detected near SN 1987A SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; supernovae : individual (SN 1987A); techniques : interferometric ID SUPERNOVA SN-1987A; SN1987A AB Speckle interferometry observations, made just 30 and 38 days after the explosion of SN 1987A (which was first seen in 1987 February 23), showed evidence of a bright source separated from the SN by only 60 mas. The reprocessing of that data, using new image reconstruction algorithms, has resulted in much cleaner images that not only clearly show the bright spot reported in 1987 but also show a second spot on the opposite side of the SN with a larger spatial separation. If the spots were ejected from the SN, then the velocities of the spots are relativistic; the second spot appears to be superluminal and must be blueshifted. We explore the consequences of these results on the geometry of the SN 1987A system, and we conclude that our observations may well be evidence of relativistic jets emanating from the supernova. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Nisenson, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 21 TC 27 Z9 27 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP L29 EP L32 DI 10.1086/312066 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211LZ UT WOS:000081163700008 ER PT J AU Ohashi, N Lee, SW Wilner, DJ Hayashi, M AF Ohashi, N Lee, SW Wilner, DJ Hayashi, M TI CCS imaging of the starless core L1544: An envelope with infall and rotation SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (L1544); ISM : kinematics and dynamics; stars : formation ID DARK CLOUD CORES; PROTOSTELLAR CORES; MOLECULAR CLOUDS; DENSE CORES; FRAGMENTATION; DISKS AB We have carried out observations of the starless core L1544 in the CCS (J(N) = 3(2)-2(1)) line at 9 mm wavelength using the Berkeley-Illinois-Maryland Association array. The maps show an elongated condensation, 0.15 x 0.045 pc in size, with stronger emission at the edges. The appearance is consistent with a flattened, ringlike structure viewed at high inclination to the line of sight. The CCS molecule is likely heavily depleted in the inner part of the core. The position velocity diagram along the major axis shows a remarkable pattern, a "tilted ellipse," that can be reproduced by a simple model ring with motions of both infall and rotation. The models suggest comparable velocities for infall and rotation, similar to 0.1 km s(-1), in the outermost envelope, at radius 15,000 AU. C1 Acad Sinica, Inst Astron & Astrophys, Taipei 115, Taiwan. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02318 USA. Subaru Telescope, Hilo, HI 96720 USA. RP Ohashi, N (reprint author), Acad Sinica, Inst Astron & Astrophys, POB 1-87, Taipei 115, Taiwan. EM ohashi@asiaa.sinica.edu.tw NR 23 TC 66 Z9 66 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP L41 EP L44 DI 10.1086/312067 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211LZ UT WOS:000081163700011 ER PT J AU Williams, JP Myers, PC AF Williams, JP Myers, PC TI A contracting, turbulent, starless core in the Serpens cluster SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (Serpens); ISM : kinematics and dynamics; stars : formation ID CLOUD CORES; AMBIPOLAR DIFFUSION; MAGNETIC BRAKING; PROTOSTARS; INFALL; OPHIUCHUS; CHEMISTRY; PROFILES; STARS AB We present combined single-dish and interferometric CS (2-1) and N2H+ (1-0) observations of a compact core in the northwest region of the Serpens molecular cloud. The core is starless according to observations from optical to millimeter wavelengths, but its lines have turbulent widths and "infall asymmetry." Line profile modeling indicates supersonic inward motions v(in) greater than or similar to 0.34 km s(-1) over an extended region L > 12,000 AU. The high infall speed and large extent exceeds the predictions of most thermal ambipolar diffusion models and points to a more dynamical process for core formation. A short (dynamic) timescale, similar to 10(5) yr similar or equal to L.v(in), is also suggested by the low N2H+ abundance, similar to 1 x 10(-10). C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Williams, JP (reprint author), Natl Radio Astron Observ, Campus Bldg 65,949 N Cherry Ave, Tucson, AZ 85721 USA. RI Williams, Jonathan/B-1643-2009; OI Williams, Jonathan/0000-0001-5058-695X NR 32 TC 24 Z9 24 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1999 VL 518 IS 1 BP L37 EP L40 DI 10.1086/312065 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 211LZ UT WOS:000081163700010 ER PT J AU McCarthy, MC Apponi, AJ Thaddeus, P AF McCarthy, MC Apponi, AJ Thaddeus, P TI Rhomboidal SiC3 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SMALL CARBON CLUSTERS; SOLID AR; ISOMERS; SPECTROSCOPY; C-4; FREQUENCIES; TRANSITION; STABILITY; MOLECULE; ANIONS AB During experiments to detect carbon chain molecules in the laboratory, an electrical discharge through a dilute mixture of silane and diacetylene was found to produce a molecule of unusual structure that is composed of only silicon and carbon. On spectroscopic analysis this molecule has been shown to have the elemental formula SiC3, a closed-shell singlet electronic ground state, and a planar rhomboidal geometry that consists of atoms in the shape of a distorted four-membered ring with a transannular carbon-carbon bond. Rhomboidal SiC3 is isovalent with rhombic C-4, a long predicted low-lying isomer of C-4 of similar structure which has so far eluded spectroscopic detection. Strong lines of SiC3 can be observed under a wide range of experimental conditions, suggesting that this molecule is quite stable, and that kinetic and thermodynamic factors favor its formation. Radio emission lines of SiC3 have now been detected in space in the molecular envelope of the carbon-rich star IRC+10216. (C) 1999 American Institute of Physics. [S0021-9606(99)01522-6]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP McCarthy, MC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI McCarthy, Michael/0000-0001-9142-0008 NR 35 TC 62 Z9 66 U1 2 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 8 PY 1999 VL 110 IS 22 BP 10645 EP 10648 DI 10.1063/1.479007 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 199FF UT WOS:000080469200001 ER PT J AU Arnoldi, MJ AF Arnoldi, MJ TI Readings in African popular culture SO AFRICAN ARTS LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Arnoldi, MJ (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CALIF PI LOS ANGELES PA AFRICAN STUDIES CNTR, LOS ANGELES, CA 90024 USA SN 0001-9933 J9 AFR ARTS JI Afr. Arts PD SUM PY 1999 VL 32 IS 2 BP 14 EP 15 DI 10.2307/3337597 PG 2 WC Art SC Art GA 216KX UT WOS:000081442400006 ER PT J AU Arnoldi, MJ AF Arnoldi, MJ TI West African popular theatre SO AFRICAN ARTS LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Arnoldi, MJ (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CALIF PI LOS ANGELES PA AFRICAN STUDIES CNTR, LOS ANGELES, CA 90024 USA SN 0001-9933 J9 AFR ARTS JI Afr. Arts PD SUM PY 1999 VL 32 IS 2 BP 14 EP 15 DI 10.2307/3337597 PG 2 WC Art SC Art GA 216KX UT WOS:000081442400005 ER PT J AU Herken, G AF Herken, G TI Destroying the village: Eisenhower and thermonuclear war. SO AMERICAN HISTORICAL REVIEW LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Herken, G (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER HISTORICAL REVIEW PI WASHINGTON PA 400 A ST SE, WASHINGTON, DC 20003 USA SN 0002-8762 J9 AM HIST REV JI Am. Hist. Rev. PD JUN PY 1999 VL 104 IS 3 BP 952 EP 953 DI 10.2307/2651084 PG 2 WC History SC History GA 209GX UT WOS:000081040800104 ER PT J AU Herken, G AF Herken, G TI Living with peril: Eisenhower, Kennedy, and nuclear weapons. SO AMERICAN HISTORICAL REVIEW LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Herken, G (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER HISTORICAL REVIEW PI WASHINGTON PA 400 A ST SE, WASHINGTON, DC 20003 USA SN 0002-8762 J9 AM HIST REV JI Am. Hist. Rev. PD JUN PY 1999 VL 104 IS 3 BP 952 EP 953 DI 10.2307/2651084 PG 2 WC History SC History GA 209GX UT WOS:000081040800103 ER PT J AU Milonni, PW AF Milonni, PW TI Resource letter: AOA-1: Adaptive optics for astronomy SO AMERICAN JOURNAL OF PHYSICS LA English DT Review ID LASER-GUIDE-STAR; WAVE-FRONT SENSOR; ATMOSPHERIC-TURBULENCE COMPENSATION; MESOSPHERIC SODIUM LAYER; FIELD-OF-VIEW; SYNTHETIC BEACON; SHEARING INTERFEROMETER; SPECKLE PATTERNS; PERFORMANCE; TELESCOPES AB This is a guide to the basic concepts and the literature on adaptive optics for astronomy. (C) 1999. American Association of Physics Teachers. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Milonni, PW (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. NR 111 TC 7 Z9 7 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD JUN PY 1999 VL 67 IS 6 BP 476 EP 485 DI 10.1119/1.19310 PG 10 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 201ET UT WOS:000080582600022 ER PT J AU Stanek, KZ Kaluzny, J Krockenberger, M Sasselov, DD Tonry, JL Mateo, M AF Stanek, KZ Kaluzny, J Krockenberger, M Sasselov, DD Tonry, JL Mateo, M TI Direct distances to nearby galaxies using detached eclipsing binaries and cepheids. III. Variables in the field M31C SO ASTRONOMICAL JOURNAL LA English DT Article DE binaries : close; Cepheids; distance scale; galaxies : individual (M31); stars : variables : other ID SYSTEM; RADII AB We undertook a long-term project, DIRECT, to obtain the direct distances to two important galaxies in the cosmological distance ladder-M31 and M33-using detached eclipsing binaries (DEBs) and Cepheids, While rare and difficult to detect, DEBs provide us with the potential to determine these distances with an accuracy better than 5%. The extensive photometry obtained in order to detect DEBs provides us with goad light curves for the Cepheid variables. These are essential to the parallel project to derive direct Baade-Wesselink distances to Cepheids in M31 and M33, For both Cepheids and eclipsing binaries, the distance estimates will be free of any intermediate steps. As a first step in the DIRECT project, between 1996 September and 1997 October we obtained 95 full/partial nights on the F. L. Whipple Observatory 1.2 m telescope and 36 full nights on the Michigan-Dartmouth-MIT 1.3 m telescope to search for DEBs and new Cepheids in the M31 and M33 galaxies. In this third paper in the series, we present the catalog of variable stars, most of them newly detected, found in the field M31C [(alpha, delta)=(11.degrees 10, 41.degrees 42), J2000.0]. We have found 115 variable stars: 12 eclipsing binaries, 35 Cepheids, and 68 other periodic, possible long-period or nonperiodic variables. The catalog of variables, as well as their photometry and finding charts, is available via anonymous ftp and the World Wide Web. The complete set of the CCD frames is available upon request. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Warsaw Univ Observ, PL-00478 Warsaw, Poland. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. RP Stanek, KZ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 31 TC 34 Z9 34 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 1999 VL 117 IS 6 BP 2810 EP 2830 DI 10.1086/300899 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 214VU UT WOS:000081348900020 ER PT J AU Huttemeister, S Aalto, S Wall, WF AF Huttemeister, S Aalto, S Wall, WF TI The discovery of a gas-rich bar in UGC 2855: a galaxy in a pre-starburst phase? SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : evolution; galaxies : individual : UGC 2855; galaxies : individual : UGC 2866; galaxies : ISM; galaxies : starburst; radio lines : galaxies ID MOLECULAR GAS; SPIRAL GALAXIES; STAR-FORMATION; CO EMISSION; RESOLUTION; KINEMATICS; MORPHOLOGY; NGC-7479; SAMPLE AB We present the first interferometric CO observations of the barred late-type galaxy UGC 2855 and its companion UGC 2866. UGC 2855 is shown to belong to the rare class of galaxies with a long (similar to 8 kpc) continuous molecular bar. The velocity field along the bar is dominated by solid-body rotation and shows few perturbations. This, together with an almost constant and low (CO)-C-12/(CO)-C-13 Line intensity ratio along the bar and in the center as well as only weak Her emission, indicate that the gas in the bar is not subjected to strong shocks, but surprisingly quiescent. In the central 3 ", a high velocity feature consisting of a number of Giant Molecular Associations, is identified. We discuss possible scenarios of the nature of this structure in connection with the question of the presence of an Inner Lindblad Resonance (ILR) in the bar. We suggest that the bar of UGC 2855 is a young object, possibly has no ILR, and that the mass concentration toward the center of the galaxy is just beginning. In contrast, the companion UGC 2866 experiences a strong starburst. We compare the properties of the gas in the bar of UGC 2855 to those we find in NGC 7479. Despite superficial parallels, the two bars are very dissimilar objects in terms of (CO)-C-12/(CO)-C-13 line ratio, velocity field and H alpha activity. NGC 7479 exhibits starburst characteristics, while we argue that UGC 2855 is in a pre-burst stage. C1 Univ Bonn, Inst Radioastron, D-53121 Bonn, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Onsala Space Observ, S-43992 Onsala, Sweden. CALTECH, Pasadena, CA 91125 USA. INAOE, Puebla 72000, Mexico. EM huette@astro.uni-bonn.de NR 52 TC 19 Z9 19 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 1999 VL 346 IS 1 BP 45 EP 57 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 203FK UT WOS:000080697300008 ER PT J AU Knapp, GR Young, K Crosas, M AF Knapp, GR Young, K Crosas, M TI The circumstellar envelope of pi(1) Gru SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE radio lines : stars; stars : AGB and post-AGB; stars : mass-loss ID MASS-LOSS; STARS; NEBULAE; SHELLS; CARBON AB CO(J = 2-1) and SiO(J = 5-4) emission has been observed from the molecular envelope around the nearby S star pi(1) Gru. The CO line profile differs from the usual parabolic shape seen in uniformly-expanding envelopes. it has a Voigt-like profile and two horns. A model for line formation in the envelope shows that a tilted, expanding disk reproduces the observations well. The star also has a fast molecular wind, with a projected outflow speed of at least 70 and perhaps as high as 90 km s(-1). The fast wind is presumably ejected from the poles of the disk. These observations show that the complex structure seen in; many planetary nebulae, including quadrupolar structure and fast winds, may largely evolve from structure formed while the progenitor star is in the last stages of evolution on the AGB. C1 Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Knapp, GR (reprint author), Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. EM gk@astro.princeton.edu; rtm@dolson.harvard.edu; mcrosas@cfa.harvard.edu NR 24 TC 17 Z9 17 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 1999 VL 346 IS 1 BP 175 EP 180 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 203FK UT WOS:000080697300023 ER PT J AU Mennesson, B Mariotti, JM du Foresto, VC Perrin, G Ridgway, S Ruilier, C Traub, WA Carleton, NP Lacasse, MG Maze, G AF Mennesson, B Mariotti, JM du Foresto, VC Perrin, G Ridgway, S Ruilier, C Traub, WA Carleton, NP Lacasse, MG Maze, G TI Thermal infrared stellar interferometry using single-mode guided optics: first results with the TISIS experiment on IOTA SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE instrumentation : interferometers; stars : fundamental parameters; stars : individual : alpha Her; stars : individual : Arcturus; infrared : stars ID NULLING INTERFEROMETER; EXTRASOLAR PLANETS; ANGULAR DIAMETER; FIBERS AB We report the first long baseline interferometric observations obtained in the thermal infrared with a single-mode fiber coupler. Stellar fringes have been found on alpha Bootis (Arcturus) and alpha Herculis, with a 21 m baseline of the Infrared and Optical Telescope Array (IOTA), located at the Smithsonian's Fred Lawrence Whipple Observatory (Mt Hopkins, Arizona). Beams from the telescopes are coherently combined through an X shaped fluoride glass single-mode fiber coupler. Although this device was not originally optimized for operation in the L band (effective wavelength of 3.75 mu m), we find good interferometric properties in that wavelength domain, with a rather high and steady instrumental transfer function, and very low dispersive effects. Observations are still limited by the poor sensitivity of the detectors and not by the thermal background, which was minimized. Visibilities derived from the interferograms are consistent with the published limb darkened diameters of alpha Herculis. It is, to our knowledge, the first time interferometric observations of Arcturus and alpha Her are reported in the L band. C1 Observ Paris, DESPA, F-92195 Meudon, France. ESO, D-85748 Garching, Germany. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Verre Fluore, F-35170 Bruz, France. RP Mennesson, B (reprint author), Observ Paris, DESPA, F-92195 Meudon, France. EM bertrand@bluenote.obspm.fr NR 26 TC 35 Z9 35 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 1999 VL 346 IS 1 BP 181 EP 189 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 203FK UT WOS:000080697300024 ER PT J AU Lorenzetti, D Tommasi, E Giannini, T Nisini, B Benedettini, M Pezzuto, S Strafella, F Barlow, M Clegg, PE Cohn, M Di Giorgio, AM Liseau, R Molinari, S Palla, F Saraceno, P Smith, HA Spinoglio, L White, GJ AF Lorenzetti, D Tommasi, E Giannini, T Nisini, B Benedettini, M Pezzuto, S Strafella, F Barlow, M Clegg, PE Cohn, M Di Giorgio, AM Liseau, R Molinari, S Palla, F Saraceno, P Smith, HA Spinoglio, L White, GJ TI ISO-LWS observations of Herbig Ae Be stars I. Fine structure lines SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : circumstellar matter; stars : pre-main sequence; infrared : ISM : lines and bands; infrared : stars ID LONG-WAVELENGTH SPECTROMETER; DEEPLY EMBEDDED COMPANION; MAIN-SEQUENCE STARS; MASS-LOSS RATES; AE/BE STARS; MOLECULAR CLOUDS; HARO OBJECTS; PHOTODISSOCIATION REGIONS; MIDINFRARED EMISSION; CIRCUMSTELLAR MATTER AB We present the results of the first spectrophotometric survey of a sample of eleven Herbig Ae/Be stars (HAEBE) obtained with the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). The [OI] 63 mu m and the [CII] 158 mu m lines an obsereved in all the investigated sources, while the [OI] 145 mu m transition, due to its relative faintness, sometimes remains undetected. By comparing line intensity ratios with model predictions, photodissociation, due to the UV photons from the central star, results the dominating excitation mechanism although contributions of C-shocks to the [OI] emission cannot be ruled out. A clear example for the presence of a photodissociation region (PDR) illuminated by an HAEBE is shown by LWS spectroscopic mapping of NGC 7129. Some diagnostic probes of the radiation held and density are provided for the objects in our sample: these substantially agree with the known characteristics of both the star and its circumstellar environment, although the observed ratio [OI]63/[OI] 145 tends to be smaller than predicted by PDR models. The most likely explanation for this behaviour is self-absorption at 63 mu m bq cold atomic oxygen. Fine structure lines of the ionised species [OIII], [NII] were detected whenever the star had a spectral type of B0 or earlier: in particular, around the star CoD-42 degrees 11721, besides a compact HII region, evidence is given for an extended low electron density ionised region. Finally, molecular line emission is associated with stars powering a CO outflow, and clumpy PDR models, better than C-shock models, predict for them relative cooling (CO vs OI and CO vs OH) similar to the observed ones. C1 Osserv Astron Roma, I-00040 Monte Porzio Catone, Italy. Agenzia Spaziale Italiana, I-00161 Rome, Italy. Univ Roma La Sapienza, Ist Astron, I-00161 Rome, Italy. CNR, Ist Fis Spazio Interplanetario, Area Ric Tor Vergata, I-00133 Rome, Italy. Univ Lecce, Dipartimento Fis, I-73100 Lecce, Italy. Univ London Univ Coll, Dept Phys & Astron, London WC1E 6BT, England. Queen Mary Univ London, London E1 4NS, England. Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. Stockholm Observ, S-13336 Saltsjobaden, Sweden. CALTECH, IPAC, Pasadena, CA 91125 USA. Osserv Astrofis Arcetri, I-50125 Florence, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Lorenzetti, D (reprint author), Osserv Astron Roma, via Frascati 33, I-00040 Monte Porzio Catone, Italy. EM dloren@coma.mporzio.astro.it RI Barlow, Michael/A-5638-2009; Molinari, Sergio/O-4095-2016; OI Barlow, Michael/0000-0002-3875-1171; Molinari, Sergio/0000-0002-9826-7525; Pezzuto, Stefano/0000-0001-7852-1971; palla, francesco/0000-0002-3321-0456; Giannini, Teresa/0000-0002-0224-096X; Spinoglio, Luigi/0000-0001-8840-1551; , Brunella Nisini/0000-0002-9190-0113 NR 64 TC 43 Z9 43 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 1999 VL 346 IS 2 BP 604 EP 616 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 212PK UT WOS:000081225300036 ER PT J AU Giannini, T Lorenzetti, D Tommasi, E Nisini, B Benedettini, M Pezzuto, S Strafella, F Barlow, M Clegg, PE Cohen, M Di Giorgio, AM Liseau, R Molinari, S Palla, F Saraceno, P Smith, HA Spinoglio, L White, GJ AF Giannini, T Lorenzetti, D Tommasi, E Nisini, B Benedettini, M Pezzuto, S Strafella, F Barlow, M Clegg, PE Cohen, M Di Giorgio, AM Liseau, R Molinari, S Palla, F Saraceno, P Smith, HA Spinoglio, L White, GJ TI ISO-LWS observations of Herbig Ae Be stars II. Molecular lines SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : circumstellar matter; stars : pre-main sequence; infrared : ISM : lines and bands; infrared : stars ID R-CORONAE-AUSTRALIS; LONG-WAVELENGTH SPECTROMETER; MAIN-SEQUENCE OBJECTS; AE/BE STARS; MIDINFRARED EMISSION; HARO OBJECTS; RHO-OPHIUCHI; DARK CLOUDS; COLD DUST; LKH-ALPHA-234 AB We present the first ISO-LWS observations of the molecular FIR lines in 3 out of a sample of 11 Herbig Ae/Be stars (HAEBE), namely IRAS12496-7650, RCrA and LkH alpha 234. High-J rotational CO lines (from J(up),, = 14 to J(up),, = 19) have been observed in all the spectra, while two (at 79 mu m and 84 mu m) and three OH lines (at 71 mu m, 79 mu m and 84 mu m) were detected in LkH alpha 234 and RCrA respectively. For all sources the molecular emission has been consistently fitted with a Large Velocity Gradient (LVG) model and it results originated in a warm (T greater than or similar to 200 K) and dense (n(H2), greater than or similar to 10(5) cm(-3)) gas located in very compact regions having diameters of few hundreds of AU. These three sources are those with the highest density among the stars of the sample; this suggests that the molecular emission arises in regions showing density peaks. By comparing the observed cooling ratios with model predictions, we find that the FUV radiation from the central source (or from a more embedded companion) is the most likely responsible for the line excitation. At least for the sources where OH has been observed, the contribution of shocks to the line emission can be reasonably ruled out because of the absence in the spectra of any water vapour lints, in contrast with the predictions for molecular emission coming from warm shocked environments. C1 Univ Roma La Sapienza, Ist Astron, I-00161 Rome, Italy. Osserv Astron Roma, I-00040 Monte Porzio Catone, Italy. CNR, Ist Fis Spazio Interplanetario, Area Ric Tor Vergata, I-00133 Rome, Italy. Agenzia Spaziale Italiana, I-00161 Rome, Italy. Univ Lecce, Dipartmento Fis, I-73100 Lecce, Italy. UCL, Dept Phys & Astron, London WC1E 6BT, England. Univ London Queen Mary & Westfield Coll, London E1 4NS, England. Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. Stockholm Observ, S-13336 Saltsjobaden, Sweden. CALTECH, IPAC, Pasadena, CA USA. Osserv Astrofis Arcetri, I-50125 Florence, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Giannini, T (reprint author), Univ Roma La Sapienza, Ist Astron, Via Lancisi 29, I-00161 Rome, Italy. EM teresa@coma.mporzio.astro.it RI Barlow, Michael/A-5638-2009; Molinari, Sergio/O-4095-2016; OI Barlow, Michael/0000-0002-3875-1171; Molinari, Sergio/0000-0002-9826-7525; palla, francesco/0000-0002-3321-0456; Pezzuto, Stefano/0000-0001-7852-1971; Giannini, Teresa/0000-0002-0224-096X; Spinoglio, Luigi/0000-0001-8840-1551; , Brunella Nisini/0000-0002-9190-0113 NR 54 TC 44 Z9 44 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 1999 VL 346 IS 2 BP 617 EP 625 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 212PK UT WOS:000081225300037 ER PT J AU Wambsganss, J Brunner, H Schindler, S Falco, E AF Wambsganss, J Brunner, H Schindler, S Falco, E TI The gravitationally lensed quasar Q2237+0305 in X-rays: ROSAT HRI detection of the "Einstein Cross" SO ASTRONOMY & ASTROPHYSICS LA English DT Letter DE cosmology : observations; cosmology : gravitational lensing; galaxies : quasars : individual : Q2237+0305; X-rays : galaxies; X-rays : general ID MICROLENSING EVENT; SYSTEM; MODELS; GALAXY AB We report the first detection of the gravitationally lensed quasar Q2237+0305 in X-rays. With a ROSAT/HRI exposure of 53 ksec taken in Nov./Dec. 1997, we found a count rate of 0.006 counts per second for the combined four images. This corresponds to an X-ray flux of 2.2 x 10(-13) erg/cm(2)/sec and an X-ray luminosity of 4.2 x 10(45) erg/sec (in the ROSAT energy window 0.1-2.4 keV). The ROSAT/HRI detector is not able to resolve spatially the four quasar images (maximum separation 1.8 arcsec). The analysis is based on about 330 source photons. The signal is consistent with no variability, but with low significance. This detection is promising in view of the upcoming X-ray missions with higher spatial/spectral resolution and/or collecting power (Chandra X-ray Observatory, XMM and ASTRO-E). C1 Astron Inst, Sternwarte 16, D-14482 Potsdam, Germany. Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead L41 1LD, Merseyside, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Wambsganss, J (reprint author), Astron Inst, Sternwarte 16, D-14482 Potsdam, Germany. EM jwambsganss@aip.de; hbrunner@aip.de; sas@astro.livjm.ac.uk; falco@cfa.harvard.edu NR 22 TC 9 Z9 9 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 1999 VL 346 IS 1 BP L5 EP L8 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 203FK UT WOS:000080697300002 ER PT J AU Vassiliev, VV AF Vassiliev, VV CA VERITAS Collaboration TI Flux sensitivity of VERITAS SO ASTROPARTICLE PHYSICS LA English DT Article AB VERITAS is a new major ground-based gamma-ray observatory with an array of seven 10 m optical reflectors to be built at the Whipple Observatory in southern Arizona, USA. It will consist of an array of imaging Cherenkov telescopes designed to conduct critical measurements of AGNs and SNRs in the energy range of 50 GeV-50 TeV. The design of the array has been optimized for the highest sensitivity to point sources in the 100 GeV-10 TeV band when the stereoscopic imaging technique is employed. Maximum versatility of the array has been another major optimization criterion. We present the flux sensitivity of the baseline VERITAS configuration. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Harvard Smithsonian Ctr Astrophys, Whipple Observ, Amado, AZ 85645 USA. RP Vassiliev, VV (reprint author), Harvard Smithsonian Ctr Astrophys, Whipple Observ, POB 97, Amado, AZ 85645 USA. NR 7 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 J9 ASTROPART PHYS JI Astropart Phys. PD JUN PY 1999 VL 11 IS 1-2 BP 247 EP 249 DI 10.1016/S0927-6505(99)00058-4 PG 3 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 212PW UT WOS:000081226300044 ER PT J AU Kaaret, P AF Kaaret, P CA VERITAS Collaboration TI VERITAS observations of compact Galactic sources SO ASTROPARTICLE PHYSICS LA English DT Article ID GAMMA-RAY OBSERVATIONS; CRAB-NEBULA AB TeV emission is a key diagnostic of physical processes occurring in a variety of compact Galactic objects. Measurement of the TeV spectra from inverse-Compton emission in pulsar-powered nebulae should permit determination of the nebular magnetic fields. Observation of TeV gamma-rays from Galactic superluminal jet sources may lead to clues about the jet production mechanism. And, observation of TeV gamma-rays from unidentified EGRET gamma-ray sources should permit accurate localization and may lead to identification of unique x-ray and optical counterparts. We discuss observations of Galactic sources planned for VERITAS including a survey of a well-populated region of Galactic plane. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kaaret, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 10 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 J9 ASTROPART PHYS JI Astropart Phys. PD JUN PY 1999 VL 11 IS 1-2 BP 259 EP 261 DI 10.1016/S0927-6505(99)00061-4 PG 3 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 212PW UT WOS:000081226300047 ER PT J AU Pratap, P Megeath, ST Bergin, EA AF Pratap, P Megeath, ST Bergin, EA TI High-angular resolution millimeter-wave and near-infrared imaging of the ultracompact HII region G29.96-0.02 SO ASTROPHYSICAL JOURNAL LA English DT Article DE HII regions; ISM : individual (G29.96-0.02); ISM : molecules; ISM : structure; stars : formation ID H-II-REGIONS; MOLECULAR CLOUDS; METHYL CYANIDE; MASSIVE STARS; PHYSICAL-PROPERTIES; VELOCITY STRUCTURE; INTRINSIC COLORS; STELLAR CLUSTER; HOT CORES; COMETARY AB We present a high-angular resolution study of the cometary-shaped ultracompact H II region G29.96-0.02. We have obtained similar to 10 " angular-resolution millimeter-wave maps of the region in transitions of (CO)-C-13, (CO)-O-18, CH3CN, CH3OH, and CS with the BIMA interferometer. We combine these data with complementary single-dish data of the (CO)-C-13, (CO)-O-18, and CS lines taken with the FCRAO 14 meter telescope. These data are compared with near-infrared JHK-band images with less than or equal to 0."19 angular resolution obtained with the Calar-Alto 3.5 m telescope. The (CO)-C-13 data show emission extended over a 3 x 2 pc region; however, the emission is strongly peaked near the head of the H II region. Strong CS, (CO)-O-18, and CH3CN emissions peak near the same location. The CH3CN (J = 6 --> 5) emission peaks toward the hot core previously detected in VLA NH3(4, 4) observations, and we determine a kinetic temperature of 100 K in the core using a large velocity gradient analysis of the CH3CN (6 --> 5) BIMA data and CH3CN/(CH3CN)-C-13 (5 --> 4) IRAM 30 m telescope data. We also find that the sharply peaked (CO)-O-18, (CO)-C-13, and CS emission is indicative of a density gradient, with the peak density located in front of the head of the cometary H II region. We use our near-infrared data to search for sources embedded in the H II region and the adjacent cloud. In addition to the exciting star of the H II region, we identify a second star toward the head of the H II region with an extinction similar to that of the exciting star; this appears to be a second OB star in the H II region. Directly in front of the H II region we detect a highly reddened source, which is most likely a young star deeply embedded in the molecular gas. Furthermore, we find an enhanced density of sources with H-K >1 toward the molecular cloud and argue that these sources form an embedded cluster. Finally, we compare our results with current models of cometary shaped H II regions. Given the evidence that the G29.96 H II region exists in a gradient of molecular gas density that peaks in front of the head of the H II region, we favor the champagne flow model for this region. Comparing the measured densities, temperatures, and line widths of the ionized and molecular gas, we estimate the expansion speed of the H II region into the molecular core at 2-5 km s(-1). C1 MIT, Haystack Observ, Westford, MA 01886 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Pratap, P (reprint author), MIT, Haystack Observ, Route 40, Westford, MA 01886 USA. NR 59 TC 46 Z9 46 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP 799 EP 818 DI 10.1086/307212 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VC UT WOS:000081011700021 ER PT J AU Jain, RK Bailyn, CD Orosz, JA Remillard, RA McClintock, JE AF Jain, RK Bailyn, CD Orosz, JA Remillard, RA McClintock, JE TI X-ray nova XTE J1550-564: Optical observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; stars : individual (XTE J1550-564); X-rays : stars ID ADVECTION-DOMINATED ACCRETION; BLACK-HOLE; GRO J1655-40; TRANSIENTS; QUIESCENCE; OUTBURST; MODEL AB We report the identification of the optical counterpart of the X-ray transient XTE J1550-564 described in two companion papers by Sobczak et al. and Remillard et al. We find that the optical source brightened by approximate to 4 mag over the quiescent counterpart seen at B approximate to 22 on a SERC survey plate and then decayed by approximate to 1.5 mag over the 7 week-long observation period. There was an optical response to the large X-ray flare described by Sobczak et al., but it was much smaller and delayed by approximate to 1 day. C1 Yale Univ, Dept Astron, New Haven, CT 06520 USA. Yale Univ, Dept Phys, New Haven, CT 06520 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Jain, RK (reprint author), Yale Univ, Dept Astron, POB 208101, New Haven, CT 06520 USA. NR 33 TC 26 Z9 26 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP L131 EP L134 DI 10.1086/312041 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VF UT WOS:000081012000015 ER PT J AU Lenz, DD DeLuca, EE Golub, L Rosner, R Bookbinder, JA AF Lenz, DD DeLuca, EE Golub, L Rosner, R Bookbinder, JA TI Temperature and emission-measure profiles along long-lived solar coronal loops observed with the Transition Region and Coronal Explorer SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : UV radiation ID MODEL AB We report an initial study of temperature and emission-measure distributions along four steady loops observed with the Transition Region and Coronal Explorer at the limb of the Sun. The temperature diagnostic is the filter ratio of the extreme-ultraviolet 171 and 195 Angstrom passbands. The emission-measure diagnostic is the count rate in the 171 Angstrom passband. We find essentially no temperature variation along the loops. We compare the observed loop structure with theoretical isothermal and nonisothermal static loop structure. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA. EM lenz@oddjob.uchicago.edu; edeluca@cfa.harvard.edu; Igolub@cfa.harvard.edu; rrosner@oddjob.uchicago.edu; jbookbinder@cfa.harvard.edu RI DeLuca, Edward/L-7534-2013 OI DeLuca, Edward/0000-0001-7416-2895 NR 18 TC 131 Z9 132 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP L155 EP L158 DI 10.1086/312045 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VF UT WOS:000081012000021 ER PT J AU Neufeld, DA Feuchtgruber, H Harwit, M Melnick, GJ AF Neufeld, DA Feuchtgruber, H Harwit, M Melnick, GJ TI Infrared Space Observatory observations of far-infrared rotational emission lines of water vapor toward the supergiant star VY Canis Majoris SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; molecular processes; stars : abundances; stars : individual (VY Canis Majoris); supergiants ID H2O EMISSION; ISO-SWS; SPECTRUM; OXYGEN; HOT AB We report the detection of numerous far-infrared emission lines of water vapor toward the supergiant star VY Canis Majoris. A 29.5-45 mu m grating scan of VY CMa, obtained using the Short-Wavelength Spectrometer (SWS) of the Infrared Space Observatory at a spectral resolving power lambda/Delta lambda of similar to 2000, reveals at least 41 spectral features due to water vapor that together radiate a total luminosity of similar to 25 L.. In addition to pure rotational transitions within the ground vibrational state, these features include rotational transitions within the (010) excited vibrational state. The spectrum also shows the (2)Pi(1/2) (J = 5/2) <-- (2)Pi(3/2) (J = 3/2) OH feature near 34.6 mu m in absorption. Additional SWS observations of VY CMa were carried out in the instrument's Fabry-Perot mode for three water transitions: the 7(25)-6(16) line at 29.8367 mu m, the 4(41)-3(12) line at 31.7721 mu m, and the 4(32)-3(03) line at 40.6909 mu m. The higher spectral resolving power lambda/Delta lambda of approximately 30,000 thereby obtained permits the line profiles to be resolved spectrally for the first time and reveals the "P Cygni" profiles that are characteristic of emission from an outflowing envelope. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Cornell Univ, Ithaca, NY 14853 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Neufeld, DA (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. NR 29 TC 25 Z9 25 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP L147 EP L150 DI 10.1086/312036 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VF UT WOS:000081012000019 ER PT J AU Quataert, E Narayan, R Reid, MJ AF Quataert, E Narayan, R Reid, MJ TI What is the accretion rate in Sagittarius A*? SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; Galaxy : center ID BLACK-HOLE MODEL; GALACTIC-CENTER; X-RAY; SPECTRUM; EMISSION; CLUSTER; GALAXY AB The radio source Sagittarius A* at the center of our Galaxy is believed to be a 2.6 x 10(6) M. black hole that accretes gas from the winds of nearby stars. We show that limits on the X-ray and infrared emission from the Galactic center provide an upper limit of similar to 8 x 10(-5) M. yr(-1) on the mass accretion rate in Sgr A*. The advection-dominated accretion flow (ADAF) model favors a rate of less than or similar to 10(-5) M. yr(-1). In comparison, the Bondi accretion rate onto Sgr A*, estimated using the observed spatial distribution of mass-losing stars and assuming noninteracting stellar winds, is similar to 3 x 10(-5) M. yr(-1). Thus, there is rough agreement between the Bondi, the ADAF, and the X-ray-inferred accretion rates for Sgr A*. We discuss uncertainties in these estimates, emphasizing the importance of upcoming observations by the Chandra X-ray Observatory for tightening the X-ray-derived limits. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Quataert, E (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Narayan, Ramesh/0000-0002-1919-2730 NR 27 TC 32 Z9 32 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP L101 EP L104 DI 10.1086/312035 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VF UT WOS:000081012000008 ER PT J AU Remillard, RA McClintock, JE Sobczak, GJ Bailyn, CD Orosz, JA Morgan, EH Levine, AM AF Remillard, RA McClintock, JE Sobczak, GJ Bailyn, CD Orosz, JA Morgan, EH Levine, AM TI X-ray nova XTE J1550-564: Discovery of a quasi-periodic oscillation near 185 Hz SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; stars : individual (XTE J1550-564); stars : oscillations; X-rays : stars ID ACCRETION DISKS AB We have investigated the X-ray timing properties of XTE J1550-564 during 60 Rossi X-Ray Timing Explorer Proportional Counter Array observations made between 1998 September 18 and November 28. We detect quasi periodic oscillations (QPOs) near 185 Hz during four time intervals. The QPO widths (FWHM) are similar to 50 Hz, and the rms amplitudes are similar to 1% of the mean flux at 2-30 keV. This is the third Galactic black hole candidate known to exhibit a transient X-ray timing signature above 50 Hz, following the 67 Hz QPO in GRS 1915+105 and the 300 Hz QPO in GRO J1655-40. However, unlike the previous cases, which appear to show stationary frequencies, the QPO frequency in XTE J1550-564 must vary by at least similar to 10% to be consistent with observations. The occurrences and properties of the QPO were insensitive to large changes in the X-ray intensity (1.5-6.8 crab). However, the QPO appearance was accompanied by changes in the energy spectrum, namely, an increase in the temperature and a decrease in the normalization of the thermal component. The QPO is also closely related to the hard X-ray power-law component of the energy spectrum since the fractional amplitude of the QPO increases with photon energy. The fast QPOs in accreting black hole binaries are thought to be effects of general relativity; however, the relevance of the specific physical models that have been proposed remains largely uncertain. Low-frequency QPOs in the range 3-13 Hz were often observed. Occasionally, at high luminosity, the rms QPO amplitude was similar to 15% of the Aux, a level previously reached only by GRS 1915+105. These extraordinary oscillations have a coherence parameter (nu/Delta nu) in the range 4-12 and are tied to the power-law component in the energy spectrum. C1 MIT, Ctr Space Res, Cambridge, MA 02139 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Dept Astron, Cambridge, MA 02138 USA. Yale Univ, Dept Astron, New Haven, CT 06520 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 105, University Pk, PA 16802 USA. RP Remillard, RA (reprint author), MIT, Ctr Space Res, Cambridge, MA 02139 USA. NR 20 TC 55 Z9 55 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP L127 EP L130 DI 10.1086/312038 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VF UT WOS:000081012000014 ER PT J AU Sobczak, GJ McClintock, JE Remillard, RA Levine, AM Morgan, EH Bailyn, CD Orosz, JA AF Sobczak, GJ McClintock, JE Remillard, RA Levine, AM Morgan, EH Bailyn, CD Orosz, JA TI X-ray nova XTE J1550-564: RXTE spectral observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; stars : individual (XTE J1550-564); X-rays : stars ID TIMING EXPLORER; BLACK-HOLE; PERFORMANCE AB Excellent coverage of the 1998 outburst of the X-ray nova XTE J1550-564 was provided by the Rossi X-Ray Timing Explorer (RXTE). XTE J1550-564 exhibited an intense (6.8 crab) flare on 1998 September 19 (UT), making it the brightest new X-ray source observed with RXTE. We present a spectral analysis utilizing 60 Proportional Counter Array spectra from 2.5-20 keV spanning 71 days and a nearly continuous All Sky Monitor light curve. The spectra were fitted to a model including multicolor blackbody disk and power-law components. XTE J1550-564 is observed in the very high, high/soft, and intermediate canonical outburst states of black hole X-ray novae. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Yale Univ, Dept Astron, New Haven, CT 06520 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. RP Sobczak, GJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS-10, Cambridge, MA 02138 USA. NR 22 TC 51 Z9 51 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP L121 EP L125 DI 10.1086/312037 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VF UT WOS:000081012000013 ER PT J AU Funk, VA Zermoglio, MF Nasir, N AF Funk, VA Zermoglio, MF Nasir, N TI Testing the use of specimen collection data and GIS in biodiversity exploration and conservation decision making in Guyana SO BIODIVERSITY AND CONSERVATION LA English DT Article DE biodiversity; biological collections; GIS; Guyana; protected areas ID INFORMATION-SYSTEMS; DIVERSITY; KNOWLEDGE; PATTERNS; ENDEMISM; HOTSPOTS; EARTH AB This paper presents the results of a study conducted at the request of the Government of Guyana by the Centre for the Study of Biological Diversity at the University of Guyana, and the Smithsonian Institution. The purpose of the study was to evaluate the utility of using systematic collections in identifying areas with a high priority for conservation. A biodiversity database and a gazetteer were assembled and interpreted primarily through the use of maps generated in ARC/INFO and ArcView. The data were examined to determine coverage and completeness, and while in general the results support a continued use of the methodology for making informed decisions in conservation related issues, several recommendations are offered in order to enhance the data. The primary use of the results of this study is in the identification of areas of interest for conservation and in the location of eleven areas covering most ecoregions in Guyana that are in need of additional study. The eleven areas have been chosen to avoid areas that are already allocated to logging and mining concessions or Amerindian lands. While it is true that this study would benefit from additional data and further analysis of those data, it is also true that decisions concerning areas for conservation in Guyana are being made in the near future, and if any data are to be used in this process, it will be those data presented in this paper. C1 Smithsonian Inst, Dept Bot, Washington, DC 20560 USA. RP Funk, VA (reprint author), Smithsonian Inst, Dept Bot, MRC 166, Washington, DC 20560 USA. EM funkv@nmnh.si.edu NR 73 TC 48 Z9 55 U1 0 U2 9 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0960-3115 J9 BIODIVERS CONSERV JI Biodivers. Conserv. PD JUN PY 1999 VL 8 IS 6 BP 727 EP 751 DI 10.1023/A:1008877222842 PG 25 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 218DU UT WOS:000081538600001 ER PT J AU Korine, C Izhaki, I Arad, Z AF Korine, C Izhaki, I Arad, Z TI Is the Egyptian fruit-bat Rousettus aegyptiacus a pest in Israel? An analysis of the bat's diet and implications for its conservation SO BIOLOGICAL CONSERVATION LA English DT Article DE fruit-bats; Rousettus aegyptiacus; diet; seed dispersal; crop damage; frugivory ID ARTIBEUS-JAMAICENSIS; OLD-WORLD; CHIROPTERA; NITROGEN; FOLIVORY; ECOLOGY; FOOD; PHYLLOSTOMIDAE; REQUIREMENTS AB The Egyptian fruit-bat Rousettus aegyptiacus is regarded as a pest for agriculture. However, no quantitative data on its diet have been collected in Israel or in other Mediterranean areas, and control measures in the past reduced populations of insectivorous bats in Israel. We therefore studied the relative importance of native versus commercially cultivated fruit plants by analysis of bat faeces. Droppings were collected during 1993-1995 in two roost-sites in the Carmel National Park. Results show that the bat feeds mainly on fruits but leaves and pollen are also eaten. Leaf eating was observed mainly during winter, when bats may face times of severe decrease in fruit availability and quality. Only four fruit species (15%) of the bat's diet are commercially grown and only two of these in the research area. Therefore the definition of the fruit-bat as a major agricultural pest should be re-examined. Two effective methods for controlling damage caused by bats are discussed. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Haifa, Dept Biol, IL-36006 Tivon, Israel. Technion Israel Inst Technol, Dept Biol, IL-32000 Haifa, Israel. Smithsonian Trop Res Inst, Balboa, Panama. RP Izhaki, I (reprint author), Univ Haifa, Dept Biol, IL-36006 Tivon, Israel. EM izhaki@research.haifa.ac.il RI Izhaki, Ido/D-5586-2011; Korine, Carmi/F-4116-2012 NR 35 TC 30 Z9 34 U1 0 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0006-3207 J9 BIOL CONSERV JI Biol. Conserv. PD JUN PY 1999 VL 88 IS 3 BP 301 EP 306 DI 10.1016/S0006-3207(98)00126-8 PG 6 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 167HR UT WOS:000078626900002 ER PT J AU Lovelock, CE Posada, J Winter, K AF Lovelock, CE Posada, J Winter, K TI Effects of elevated CO2 and defoliation on compensatory growth and photosynthesis of seedlings in a tropical tree, Copaifera aromatica SO BIOTROPICA LA English DT Article DE compensatory growth; Copaifera aromatica; elevated CO2; Panama; photosynthesis; tropical forest ID CARBON-DIOXIDE; SIMULATED HERBIVORY; PLANT; PATTERNS; FOREST; ACCLIMATION; RESPONSES; CAPACITY; FITNESS; STRESS AB After defoliation by herbivores, some plants exhibit enhanced rates of photosynthesis and growth that enable them to compensate for lost tissue, thus maintaining their fitness relative to competing, undefoliated plants. Our aim was to determine whether compensatory photosynthesis and growth would be altered by increasing concentrations of atmospheric CO2. Defoliation of developing leaflets on seedlings of a tropical tree, Copaifera aromatica, caused increases in photosynthesis under ambient CO2, but not under elevated CO2. An enhancement in the development of buds in the leaf axils followed defoliation at ambient levels of CO2. In contrast, under elevated CO2, enhanced development of buds occurred in undefoliated plants with no further enhancement in bud development due to exposure to elevated CO2. Growth of leaf area after defoliation was increased, particularly under elevated CO2. Despite this increase, defoliated plants grown under elevated CO2 were further from compensating for tissue lost during defoliation after 5-1/2 weeks than those grown under ambient CO2 concentrations. C1 Smithsonian Trop Res Inst, Balboa, Panama. RP Lovelock, CE (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. RI Lovelock, Catherine/G-7370-2012 OI Lovelock, Catherine/0000-0002-2219-6855 NR 31 TC 16 Z9 17 U1 0 U2 8 PU ASSOC TROPICAL BIOLOGY INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0006-3606 J9 BIOTROPICA JI Biotropica PD JUN PY 1999 VL 31 IS 2 BP 279 EP 287 DI 10.1111/j.1744-7429.1999.tb00139.x PG 9 WC Ecology SC Environmental Sciences & Ecology GA 217VZ UT WOS:000081520800008 ER PT J AU Kalko, EKV Friemel, D Handley, CO Schnitzler, HU AF Kalko, EKV Friemel, D Handley, CO Schnitzler, HU TI Roosting and foraging behavior of two Neotropical gleaning bats, Tonatia silvicola and Trachops cirrhosus (Phyllostomidae) SO BIOTROPICA LA English DT Article DE conservation; ecology; foraging; forest fragmentation; Microchiroptera; radio-tracking; roost ID FALSE VAMPIRE BAT; TROPICAL RAIN-FOREST; FROG-EATING BAT; NYCTERIS-GRANDIS; MEGADERMA-LYRA; CARDIODERMA-COR; AFRICAN BAT; HABITAT USE; CHIROPTERA; VOCALIZATIONS AB We studied roosting and foraging behavior of two Neotropical gleaning bars, d'Orbigny's round-eared bar, Tonatia silvicola, and the fringe-lipped bat, Trachops cirrhosus (Phyllostomidae). Techniques included radio-tracking in a tropical lowland forest in Panama and analysis of data from long-term studies in Panama and Venezuela. Day roosts of I: silvicola were in arboreal termite nests. T. cirrhosus roosted in a hollow tree. T. silvicola emerged late (ca 60 min after sunset), and foraged close to the roosts (maximum distance 200-500 In). T. cirrhosus emerged early (ca 30 min after local sunset), and foraged farther from its roost (>1.5 km). Both bats used small foraging areas (3-12 ha) in tall, open Forest. They foraged in continuous flight (maximum 27-36 min) or in short sally flights (<1 minute) from perches ("hang-and-wait" strategy). The small foraging areas of these bars and their sedentary foraging mode most likely make them vulnerable to habitat fragmentation. C1 Univ Tubingen, D-72076 Tubingen, Germany. Smithsonian Trop Res Inst, Balboa, Panama. Natl Museum Nat Hist, Div Mammals, Washington, DC 20560 USA. RP Kalko, EKV (reprint author), Univ Tubingen, Morgenstelle 28, D-72076 Tubingen, Germany. NR 61 TC 72 Z9 75 U1 2 U2 28 PU ASSOC TROPICAL BIOLOGY INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0006-3606 J9 BIOTROPICA JI Biotropica PD JUN PY 1999 VL 31 IS 2 BP 344 EP 353 DI 10.1111/j.1744-7429.1999.tb00146.x PG 10 WC Ecology SC Environmental Sciences & Ecology GA 217VZ UT WOS:000081520800015 ER PT J AU Ott, K AF Ott, K TI All the modern conveniences: American household plumbing, 1840-1890. SO BULLETIN OF THE HISTORY OF MEDICINE LA English DT Book Review C1 Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. RP Ott, K (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4319 USA SN 0007-5140 J9 B HIST MED JI Bull. Hist. Med. PD SUM PY 1999 VL 73 IS 2 BP 336 EP 338 DI 10.1353/bhm.1999.0070 PG 3 WC Health Care Sciences & Services; History & Philosophy Of Science SC Health Care Sciences & Services; History & Philosophy of Science GA 205XA UT WOS:000080844800030 ER PT J AU Bowen, WD Boness, DJ Iverson, SJ AF Bowen, WD Boness, DJ Iverson, SJ TI Diving behaviour of lactating harbour seals and their pups during maternal foraging trips SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID PHOCA-VITULINA; PATTERNS; MASS AB Female harbour seals (Phoca vitulina) undertake foraging trips during mid to late lactation. We show that they are accompanied by their pup during many of these foraging trips. Time-depth recorder data were obtained from 20 lactating females and 14 of their pups in 1995 and 1996 at Sable Island, Nova Scotia. Overall, females spent 55.4 +/- 4.68% (mean +/- SE) of their time at sea compared with 39.8 +/- 2.29% for pups. Like those of their mothers, pups' dives occurred in clusters or bouts: 71.4 +/- 4.4 dives, 2.5 +/- 0.15 h in duration. Bouts of diving by females and pups began 0-3 days post partum. Mean dive duration of pups increased from about 1 to 1.5 min over the course of lactation, but was still shorter than that of adult females (1.5-2.25 min). Both females and pups appeared to dive within their theoretical aerobic dive limits (TADL) of 8.9 and 2.6-3.1 min, respectively. Up to 3.6% of dives by some pups may have exceeded their TADL. Pups appeared to compensate for their lesser diving ability by making more and shorter dives per bout than females, particularly during early lactation. C1 Fisheries & Oceans Canada, Bedford Inst Oceanog, Marine Fish Div, Dartmouth, NS B2Y 4A2, Canada. Smithsonian Inst, Natl Zool Pk, Dept Zool Res, Washington, DC 20008 USA. Dalhousie Univ, Dept Biol, Halifax, NS B3H 4J1, Canada. RP Bowen, WD (reprint author), Fisheries & Oceans Canada, Bedford Inst Oceanog, Marine Fish Div, POB 1006, Dartmouth, NS B2Y 4A2, Canada. RI Bowen, William/D-2758-2012 NR 14 TC 72 Z9 72 U1 2 U2 18 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD JUN PY 1999 VL 77 IS 6 BP 978 EP 988 DI 10.1139/cjz-77-6-978 PG 11 WC Zoology SC Zoology GA 252NW UT WOS:000083509500018 ER PT J AU Ward, DC AF Ward, DC TI North Carolina yeoman. The diary of Basil Armstrong Thomasson, 1853-1862 SO CIVIL WAR HISTORY LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Ward, DC (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU KENT STATE UNIV PRESS PI KENT PA C/O JOURNALS DEPT, KENT, OH 44242 USA SN 0009-8078 J9 CIVIL WAR HIST JI Civil War Hist. PD JUN PY 1999 VL 45 IS 2 BP 173 EP 174 PG 2 WC History SC History GA 213QY UT WOS:000081285800016 ER PT J AU Greenberg, R Droege, S AF Greenberg, R Droege, S TI On the decline of the rusty blackbird and the use of ornithological literature to document long-term population trends SO CONSERVATION BIOLOGY LA English DT Article AB Unlike most American blackbirds, Rusty Blackbirds (Euphagus carolensis) have shown steep population declines. Declines of approximately 90% are indicated for three recent decades from the Breeding Bird Survey, Christmas Bird Counts, and Quebec Checklist Program. Analyses of abundance classifications in bird distribution books and annotated checklists reveal an overlooked but long-term decline dating back to at least the early part of this century. Rusty Blackbirds were described ns very common to abundant in 56% of the pre-1920 published accounts, 19% of the 1921-1950 accounts, and only 7% of the post-1950 accounts. Rusty, Blackbirds were described ns uncommon in none of the pre-1950 accounts, 18% of the 1951-1980 accounts, and 43% of the post-1980 accounts. A similar pattern was found for analyses based on local checklists. Destruction of wooded wetlands on wintering grounds, acid precipitation, and the conversion of boreal forest wetlands could have contributed to these declines. Systematic analysis of regional guides and checklists provides a valuable tool for examining large-scale and long-term population changes in birds. C1 Smithsonian Migratory Bird Ctr, Natl Zool Pk, Washington, DC 20008 USA. US Geol Survey, Patuxent Wildlife Res Ctr, Biol Resources Div, Laurel, MD 20708 USA. RP Greenberg, R (reprint author), Smithsonian Migratory Bird Ctr, Natl Zool Pk, Washington, DC 20008 USA. NR 31 TC 34 Z9 36 U1 0 U2 17 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD JUN PY 1999 VL 13 IS 3 BP 553 EP 559 DI 10.1046/j.1523-1739.1999.97478.x PG 7 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 203RJ UT WOS:000080720400012 ER PT J AU Weil, SE AF Weil, SE TI From being about something to being for somebody: The ongoing transformation of the American museum SO DAEDALUS LA English DT Article C1 Smithsonian Inst, Ctr Museum Studies, Washington, DC 20560 USA. RP Weil, SE (reprint author), Smithsonian Inst, Ctr Museum Studies, Washington, DC 20560 USA. NR 34 TC 32 Z9 34 U1 0 U2 5 PU DAEDALUS PI CAMBRIDGE PA 136 IRVING ST, STE 100, CAMBRIDGE, MA 02138 USA SN 0011-5266 J9 DAEDALUS JI Daedalus PD SUM PY 1999 VL 128 IS 3 BP 229 EP 258 PG 30 WC Humanities, Multidisciplinary; Social Sciences, Interdisciplinary SC Arts & Humanities - Other Topics; Social Sciences - Other Topics GA 231BM UT WOS:000082286200010 ER PT J AU Petit, LJ Petit, DR Christian, DG Powell, HDW AF Petit, LJ Petit, DR Christian, DG Powell, HDW TI Bird communities of natural and modified habitats in Panama SO ECOGRAPHY LA English DT Article ID OVERWINTERING NEARCTIC MIGRANTS; RAIN-FOREST FRAGMENTS; ELEVATIONAL GRADIENT; POPULATION DECLINES; COFFEE PLANTATIONS; SPECIES RICHNESS; TROPICAL FORESTS; MIGRATORY BIRDS; SHADE COFFEE; LOS-TUXTLAS AB Only a small proportion of land can realistically be protected as nature reserves and thus conservation efforts also must focus on the ecological value of agroecosystems and developed areas surrounding nature reserves. In this study, avian communities were surveyed in 11 habitat types in central Panama, across a gradient from extensive forest to intensive agricultural land uses, to examine patterns of species richness and abundance and community composition. Wooded habitats, including extensive and fragmented forests, shade coffer plantations, and residential areas supported the most species and individuals. Nearctic-Neotropical migratory species were most numerous in lowland forest fragments, shade coffee, and residential areas. Introduced Pinus caribbea and sugar cane plantations supported the fewest species compared to all other habitats. Cattle pastures left fallow for less than two years supported more than twice as many total species as actively grazed pastures, such that species richness in fallow pastures was similar to that found in wooded habitats. Community similarities were relatively low among all habitat types (none exceeding the observed 65% similarity between extensive and fragmented lowland forests), bur communities in shade coffee and residential areas were 43% and 54% similar to lowland forest fragments, respectively. Fallow pastures and residential areas shared 60% of their species. Bird communities in shade coffee and residential areas were characterized by higher proportions of frugivorous and nectarivorous species than in native forests. These same guilds also were better represented in fallow than in grazed pastures. Raptors and piscivorous species were most prevalent in cattle pastures and rice fields. These results, though based upon only species richness and abundance, demonstrate that many human-altered habitats have potential ecological value for birds, and conservation efforts in tropical areas should focus greater attention on enhancement of agricultural and developed lands as wildlife habitat. To understand the true conservation value of these modified lands will require examination not only of numbers but also of the types of species supported by these habitats, their reproductive output and survival rates. C1 Smithsonian Inst, Natl Zool Pk, Smithsonian Migratory Bird Ctr, Washington, DC 20008 USA. US Geol Survey, Biol Resources Div, Reston, VA 20192 USA. Louisiana State Univ, Museum Nat Sci, Baton Rouge, LA 70803 USA. Univ Montana, Dept Organismal Biol & Ecol, Missoula, MT 59812 USA. RP Petit, LJ (reprint author), Smithsonian Inst, Natl Zool Pk, Smithsonian Migratory Bird Ctr, Washington, DC 20008 USA. NR 77 TC 83 Z9 90 U1 7 U2 45 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0906-7590 J9 ECOGRAPHY JI Ecography PD JUN PY 1999 VL 22 IS 3 BP 292 EP 304 DI 10.1111/j.1600-0587.1999.tb00505.x PG 13 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 203QY UT WOS:000080719400010 ER PT J AU Finn, M Kangas, P Adey, W AF Finn, M Kangas, P Adey, W TI Mangrove ecosystem development in Biosphere 2 SO ECOLOGICAL ENGINEERING LA English DT Article DE Biosphere 2; mangroves; mesocosms; understory ID MESOCOSM; FLORIDA AB Southwest Florida mangrove forest vegetation was successfully transplanted into a mesocosm within Biosphere 2. Dense stands of mangroves with characteristics comparable to natural Florida mangrove forests developed from the small seedlings and saplings initially installed in the mesocosm. Mangrove overstory was evaluated by leaf area index which ranged from 2.16 to 4.02 m(2)/m(2). Mangrove understory decrease was monitored as the mangrove overstory developed. The Biosphere 2 mesocosm is compared with a similarly planted mesocosm at the Smithsonian Institution in Washington DC. The performance of these mesocosms is used to evaluate existing theories on natural mangrove forest species composition. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Maryland, Nat Resources Management Program, College Pk, MD 20742 USA. Smithsonian Inst, Natl Museum Nat Hist, Marine Syst Lab, Washington, DC 20009 USA. RP Finn, M (reprint author), POB 372, Goodland, FL 34140 USA. RI Adey, Walter/G-2858-2011 NR 21 TC 5 Z9 7 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD JUN PY 1999 VL 13 IS 1-4 BP 173 EP 178 DI 10.1016/S0925-8574(98)00097-4 PG 6 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA 217CK UT WOS:000081482100011 ER PT J AU Gacia, E Littler, MM Littler, DS AF Gacia, E Littler, MM Littler, DS TI An experimental test of the capacity of food web interactions (fish-epiphytes-seagrasses) to offset the negative consequences of eutrophication on seagrass communities SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE seagrasses; epiphytes; competition; fish-grazers; functional morphology; macroalgae; Thalassia testudinum; Indian River Lagoon ID INDIAN-RIVER LAGOON; FUNCTIONAL-FORM GROUPS; THALASSIA-TESTUDINUM; WESTERN-AUSTRALIA; COCKBURN SOUND; BOTTOM-UP; FLORIDA; PRODUCTIVITY; NUTRIENT; GROWTH AB A mechanism of competition between epiphytes and seagrasses potentially modulated by grazers was studied in a high-nutrient Thalassia testudinum meadow in the Indian River Lagoon (Florida, U.S.A.). The effects of fish grazing on epiphytes, and likely enhancing T. testudinum growth, was tested through an exclusion experiment. Twelve (2 x 2 m) independent experimental plots were selected within a shallow monospecific bed to which three randomized treatments (exclusion fences, open fences and controls) with four replicates each were assigned. The epiphyte load was monitored on T. testudinum leaves inside the plots from January 1995 to March 1996. Treatment effects occurred during a chlorophyte bloom in March 1995, when the epiphyte biomass was significantly higher inside the exclusion cages than in either of the controls. The composition of the epiphytic community in March 1995 was dominated by sheet-like Enteromorpha and filamentous algae such as Cladophora, which are less resistant to herbivory than the coarsely-branched forms of red algae (e.g. Hypnea, Chondria and Acanthophora) that bloomed subsequently. These results suggest that herbivory change seasonally depending on the availability of different prey species to fish-grazers, which preferentially utilize the fleshy green algae typical of bloom conditions over the thicker coarsely-branched red algae. In the nutrient-rich lagoon the role of top-down interactions in enhancing T. testudinum growth is limited to the reduction of shading by green macroalgae. (C) 1999 Academic Press. C1 Smithsonian Marine Stn Link Port, Ft Pierce, FL 34946 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. Harbor Branch Oceanog Inst Inc, Div Marine Sci, Ft Pierce, FL 34946 USA. RP Gacia, E (reprint author), Smithsonian Marine Stn Link Port, 5612 Old Dixie Highway, Ft Pierce, FL 34946 USA. RI Gacia, Esperanca/J-9238-2012 OI Gacia, Esperanca/0000-0002-7687-7437 NR 50 TC 33 Z9 34 U1 8 U2 26 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0272-7714 J9 ESTUAR COAST SHELF S JI Estuar. Coast. Shelf Sci. PD JUN PY 1999 VL 48 IS 6 BP 757 EP 766 DI 10.1006/ecss.1999.0477 PG 10 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 215EL UT WOS:000081368900011 ER PT J AU Lessios, HA Kessing, BD Robertson, DR Paulay, G AF Lessios, HA Kessing, BD Robertson, DR Paulay, G TI Phylogeography of the pantropical sea urchin Eucidaris in relation to land barriers and ocean currents SO EVOLUTION LA English DT Article DE biogeography; cytochrome oxidase; gene flow; islands; mitochondrial DNA; ocean currents; sea urchins ID TROPICAL EASTERN PACIFIC; MITOCHONDRIAL-DNA; GENETIC-DISTANCE; ATLANTIC-OCEAN; EVOLUTION; GALAPAGOS; BIOGEOGRAPHY; SPECIATION; RATES; FLOW AB The pantropical sea urchin genus Eucidaris contains four currently recognized species, all of them allopatric: E. metularia in the Indo-West Pacific, E. thouarsi in the eastern Pacific, E. tribuloides in both the western and eastern Atlantic, and E. clavata at the central Atlantic islands of Ascension and St. Helena. We sequenced a 640-bp region of the cytochrome oxidase I (COI) gene of mitochondrial DNA to determine whether this division of the genus into species was confirmed by molecular markers, to ascertain their phylogenetic relations, and to reconstruct the history of possible dispersal and vicariance events that led to present-day patterns of species distribution. We found that E. metularia split first from the rest of the extant species of the genus. If COI divergence is calibrated by the emergence of the Isthmus of Panama, the estimated date of the separation of the Indo-West Pacific species is 4.7-6.4 million years ago. This date suggests that the last available route of genetic contact between the Indo-Pacific and the rest of the tropics was from west to east through the Eastern Pacific Barrier, rather than through the Tethyan Sea or around the southern tip of Africa. The second cladogenic event was the separation of eastern Pacific and Atlantic populations by the Isthmus of Panama. Eucidaris at the outer eastern Pacific islands (Galapagos, Isla del Coco, Clipperton Atoll) belong to a separate clade, so distinct from mainland E thouarsi as to suggest that this is a different species, for which the name E. galapagensis is revived from the older taxonomic literature. Complete lack of shared alleles in three allozyme loci between island and mainland populations support their separate specific status. Eucidaris galapagensis and E. thouarsi are estimated from their COI divergence to have split at about the same time that E. thouarsi and E. tribuloides were being separated by the Isthmus of Panama. Even though currents could easily convey larvae between the eastern Pacific islands and the American mainland, the two species do not appear to have invaded each other's ranges. Conversely, the central Atlantic E. clavata at St. Helena and Ascension is genetically similar to E; tribuloides from the American and African coasts. Populations on these islands are either genetically connected to the coasts of the Atlantic or have been colonized by extant mitochondrial DNA lineages of Eucidaris within the last 200,000 years. Although it is hard to explain how larvae can cross the entire width of the Atlantic within their competent lifetimes, COI sequences of Eucidaris from the west coast of Africa are very similar to those of E. tribuloides from the Caribbean. F-ST statistics indicate that gene flow between E. metularia from the Indian Ocean and from the western and central Pacific is restricted. Low gene flow is also evident between populations of E. clavata from Ascension and St. Helena. Rates of intraspecific exchange of genes in E. thouarsi, E. galapagensis, and E. tribuloides, on the other hand, are high. The phylogeny of Eucidaris confirms Ernst Mayr's conclusions that major barriers to the dispersal of tropical echinoids have been the wide stretch of deep water between central and eastern Pacific, the cold water off the southwest coast of Africa, and the Isthmus of Panama. It also suggests that a colonization event in the eastern Pacific has led to speciation between mainland and island populations. C1 Smithsonian Trop Res Inst, Balboa, Panama. Univ Guam, Marine Lab, Mangilao, GU 96923 USA. RP Lessios, HA (reprint author), Smithsonian Trop Res Inst, Box 2072, Balboa, Panama. NR 100 TC 151 Z9 160 U1 3 U2 30 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 USA SN 0014-3820 J9 EVOLUTION JI Evolution PD JUN PY 1999 VL 53 IS 3 BP 806 EP 817 DI 10.2307/2640720 PG 12 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 217PC UT WOS:000081507300014 ER PT J AU Sorensen, SS Luhr, JF AF Sorensen, SS Luhr, JF TI Rocks redux at the Smithsonian SO GEOTIMES LA English DT Article C1 Smithsonian Inst, Dept Mineral Sci, Natl Museum Nat Hist, Washington, DC 20560 USA. RP Sorensen, SS (reprint author), Smithsonian Inst, Dept Mineral Sci, Natl Museum Nat Hist, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 USA SN 0016-8556 J9 GEOTIMES JI Geotimes PD JUN PY 1999 VL 44 IS 6 BP 14 EP 17 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 220AG UT WOS:000081641100013 ER PT J AU Summers, K Weigt, LA Boag, P Bermingham, E AF Summers, K Weigt, LA Boag, P Bermingham, E TI The evolution of female parental care in poison frogs of the genus Dendrobates: Evidence from mitochondrial DNA sequences SO HERPETOLOGICA LA English DT Article DE poison frogs; Dendrobates; parental care; evolution; mtDNA ID BROOD CARE; POSITION; BEHAVIOR; PUMILIO; AURATUS; ANURA AB We used nucleotide sequences from portions of the mitochondrial cytochrome b, cytochrome oxidase I and 16s rRNA gene regions to evaluate phylogenetic relationships within the genus Dendrobates, a group of neotropical poison frogs with complex parental behaviors. Mapping of parental care behaviors on the phylogenetic tree derived from the molecular analysis suggests that female-only care has evolved once within Dendrobates, after passing through a biparental stage involving male egg attendance and female tadpole transport and feeding. Phylogenetic analysis also suggests that female provisioning behaviors observed in some Amazonian species of poison frogs may have arisen independently from male care in this genus. Low levels of divergence between groups from Central and South America may have speciated relatively recently (after the formation of the current Panamanian land bridge in the Pliocene). C1 E Carolina Univ, Dept Biol, Greenville, NC 27858 USA. Field Museum Nat Hist, Chicago, IL 60605 USA. Queens Univ, Dept Biol, Kingston, ON K7L 3N6, Canada. Smithsonian Trop Res Inst, Balboa, Panama. RP Summers, K (reprint author), E Carolina Univ, Dept Biol, Howell Sci Complex, Greenville, NC 27858 USA. RI Boag, Peter/B-2907-2014 OI Boag, Peter/0000-0003-0050-2089 NR 46 TC 42 Z9 47 U1 0 U2 14 PU HERPETOLOGISTS LEAGUE PI EMPORIA PA EMPORIA STATE UNIV, DIVISION BIOLOGICAL SCIENCES, 1200 COMMERCIAL ST, EMPORIA, KS 66801-5087 USA SN 0018-0831 EI 1938-5099 J9 HERPETOLOGICA JI Herpetologica PD JUN PY 1999 VL 55 IS 2 BP 254 EP 270 PG 17 WC Zoology SC Zoology GA 272BF UT WOS:000084630100015 ER PT J AU Verghese, S Duerr, EK McIntosh, KA Duffy, SM Calawa, SD Tong, CYE Kimberk, R Blundell, R AF Verghese, S Duerr, EK McIntosh, KA Duffy, SM Calawa, SD Tong, CYE Kimberk, R Blundell, R TI A photomixer local oscillator for a 630-GHz heterodyne receiver SO IEEE MICROWAVE AND GUIDED WAVE LETTERS LA English DT Article DE Gallium materials devices; photomixers; submillimeter wave oscillators; superconductor-insulator-superconductor mixers ID TEMPERATURE-GROWN GAAS; DIODE-LASERS; POWER AB A photomixer local oscillator (LO) operating at the 630-GHz difference frequency of two laser diodes was successfully demonstrated with a heterodyne detector based on a niobium superconducting tunnel junction. The low-temperature-grown GaAs photomixer generated 0.20 mu W in the input spatial mode of the receiver. Using the photomixer LO, the double-sideband noise temperature of the receiver was 331 K-in good agreement with the 323-K noise temperature obtained when a multiplied Gunn oscillator generating 0.25 mu W was substituted for the photomixer. C1 MIT, Lincoln Lab, Lexington, MA 02420 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Verghese, S (reprint author), MIT, Lincoln Lab, 244 Wood St, Lexington, MA 02420 USA. OI Tong, Edward/0000-0002-7736-4203 NR 16 TC 31 Z9 31 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8207 J9 IEEE MICROW GUIDED W JI IEEE Microw. Guided Wave Lett. PD JUN PY 1999 VL 9 IS 6 BP 245 EP 247 DI 10.1109/75.769535 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 207XU UT WOS:000080961700009 ER PT J AU Kawamura, JH Tong, CYE Blundell, R Papa, DC Hunter, TR Gol'tsman, G Cherednichenko, S Voronov, B Gershenzon, E AF Kawamura, JH Tong, CYE Blundell, R Papa, DC Hunter, TR Gol'tsman, G Cherednichenko, S Voronov, B Gershenzon, E TI An 800 GHz NbN phonon-cooled hot-electron bolometer mixer receiver SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB We describe a heterodyne receiver developed for astronomical applications to operate in the 350 mu m atmospheric window. The waveguide receiver employs a superconductive NbN phonon-cooled hot-electron bolometer mixer. The double sideband receiver noise temperature closely follows 1 K GHz(-1) across 780-870 GHz, with the intermediate frequency centered at 1.4 GHz. The conversion loss is about 15 dB. The receiver was installed for operation at the University of Arizona/Max Planck Institute for Radio Astronomy Submillimeter Telescope facility. The instrument was successfully used to conduct test observations of a number of celestial sources in a number of astronomically important spectral lines. C1 CALTECH, Pasadena, CA 91125 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Moscow State Pedag Univ, Moscow 119435, Russia. RP Kawamura, JH (reprint author), CALTECH, 320-47, Pasadena, CA 91125 USA. RI Cherednichenko, Sergey/E-9889-2011; OI Cherednichenko, Sergey/0000-0002-5397-8024; Tong, Edward/0000-0002-7736-4203 NR 6 TC 8 Z9 8 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3753 EP 3756 DI 10.1109/77.783844 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500224 ER PT J AU Amos, RS Lichtenberger, AW Tong, CE Blundell, R Pan, SK Kerr, AR AF Amos, RS Lichtenberger, AW Tong, CE Blundell, R Pan, SK Kerr, AR TI Nb/Al-AlOx/Nb edge junctions for distributed mixers SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID TUNNEL-JUNCTIONS; FABRICATION AB We have fabricated high quality Nb/Al-oxide/Al/Nb edge junctions using a Nb/SiO2 bi-layer film as the base electrode, suitable for use as traveling wave mixers. An edge is cut in the bi-layer with an ion gun at a 45 degree angle using a photoresist mask. The wafer is then cleaned in-situ with a physical ion gun clean followed by the deposition of a thin Al (al) film, which is then thermally oxidized, an optional second Al (a2) layer, and a Nb counter electrode. It was found that devices with an a2 layer resulted in superior electrical characteristics, though proximity effects increased strongly with a2 thickness. The counter electrode is defined with an SF6 + N-2 reactive ion etch, using the Al barrier layer as an etch stop. The Al barrier layer is then either removed with an Al wet etch to isolate the individual devices, or the devices are separated with an anodization process. Various ion gun cleaning conditions have been examined; in addition, both wet and plasma etch bi-layer edge surface pre-treatments were investigated. It was found that edge junctions with large widths (i.e., those more suitable for traveling wave mixers) typically benefitted more from such treatments. Initial receiver results at 260 GHz have yielded a DSB noise temperature of 60 K. C1 Univ Virginia, Dept Elect Engn, Charlottesville, VA USA. Smithsonian Astrophys Observ, Cambridge, MA USA. Natl Radio Astron Observ, Charlottesville, VA USA. RP Amos, RS (reprint author), IBM Corp, Burlington, VT 05402 USA. OI Tong, Edward/0000-0002-7736-4203 NR 12 TC 2 Z9 2 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3878 EP 3881 DI 10.1109/77.783874 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500254 ER PT J AU Marvin, UB AF Marvin, UB TI Fire in the sky: Cornets and meteors, the decisive centuries, in British ar and science. SO ISIS LA English DT Book Review C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Marvin, UB (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0021-1753 J9 ISIS JI Isis PD JUN PY 1999 VL 90 IS 2 BP 365 EP 366 DI 10.1086/384358 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 219HH UT WOS:000081601500040 ER PT J AU Horowitz, A AF Horowitz, A TI Israeli Mediterranean music - Straddling disputed territories SO JOURNAL OF AMERICAN FOLKLORE LA English DT Article C1 Smithsonian Inst, Ctr Folklife & Cultural Heritage, Washington, DC 20560 USA. RP Horowitz, A (reprint author), Smithsonian Inst, Ctr Folklife & Cultural Heritage, Washington, DC 20560 USA. NR 25 TC 6 Z9 6 U1 0 U2 0 PU AMER ANTHROPOLOGICAL ASSOC PI ARLINGTON PA 4350 NORTH FAIRFAX DRIVE SUITE 640, ARLINGTON, VA 22203 USA SN 0021-8715 J9 J AM FOLKLORE JI J. Am. Folk. PD SUM PY 1999 VL 112 IS 445 BP 450 EP 463 DI 10.2307/541372 PG 14 WC Folklore SC Arts & Humanities - Other Topics GA 224KV UT WOS:000081899000013 ER PT J AU Stott, AW Evershed, RP Jim, S Jones, V Rogers, JM Tuross, N Ambrose, S AF Stott, AW Evershed, RP Jim, S Jones, V Rogers, JM Tuross, N Ambrose, S TI Cholesterol as a new source of palaeodietary information: Experimental approaches and archaeological applications SO JOURNAL OF ARCHAEOLOGICAL SCIENCE LA English DT Article; Proceedings Paper CT 5th Advanced Seminar on Paleodiet CY SEP 01-05, 1997 CL VALBONNE, FRANCE SP Ctr Rech Archeolog DE cholesterol; stable isotopes; delta C-13 values; compound specific; laboratory animal feeding experiments; palaeodiet ID ISOTOPIC COMPOSITION; DELTA-C-13 ANALYSIS; NATURAL-ABUNDANCE; CARBON ISOTOPES; HUMAN DIET; BONE; COLLAGEN; PRESERVATION; NITROGEN; ANIMALS C1 Univ Bristol, Bristol BS8 1TS, Avon, England. Bristol Royal Infirmary, Univ Div Med, Rheumatology Unit, Bristol BS2 8HW, Avon, England. Smithsonian Inst, Conservation Anal Lab, Washington, DC 20560 USA. Univ Illinois, Dept Anthropol, Urbana, IL 61801 USA. RP Stott, AW (reprint author), Univ Bristol, Bristol BS8 1TS, Avon, England. RI STOTT, ANDREW /I-7920-2012 NR 38 TC 31 Z9 31 U1 1 U2 17 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0305-4403 J9 J ARCHAEOL SCI JI J. Archaeol. Sci. PD JUN PY 1999 VL 26 IS 6 BP 705 EP 716 DI 10.1006/jasc.1998.0386 PG 12 WC Anthropology; Archaeology; Geosciences, Multidisciplinary SC Anthropology; Archaeology; Geology GA 207HK UT WOS:000080931200013 ER PT J AU Cote, R Dalgarno, A AF Cote, R Dalgarno, A TI Mechanism for the production of Li-6(2) and Li-7(2) ultracold molecules SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article; Proceedings Paper CT 53rd OSU International Symposium on Molecular Spectroscopy CY JUN 18, 1998 CL COLUMBUS, OHIO SP Ohio State Univ DE photoassociation; spectroscopy; cold collisions; lithium; ultracold molecules; spontaneous emission; stimulated emission; oscillator strength; Franck-Condon factor ID PHOTOASSOCIATION; TRAP AB Calculations are presented of the spontaneous emission probabilities and oscillator strengths of transitions between the vibrational energy levels of the ground and excited singlet and triplet states of the molecules Li-6(2) and Li-7(2). The fractions of transitions into the continuum and the discrete levels are estimated and it is shown that the translationally cold molecules can be produced during photoassociation experiments with high efficiency. The data are used to quantify a scheme by which translationally cold molecules can be created in specific rotational and vibrational levels. (C) 1999 Academic Press. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Cote, R (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. NR 15 TC 26 Z9 26 U1 0 U2 4 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUN PY 1999 VL 195 IS 2 BP 236 EP 245 DI 10.1006/jmsp.1999.7837 PG 10 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 200XL UT WOS:000080565400004 ER PT J AU Lourenco-De-Oliveira, R Harbach, RE Castro, MG Motta, MA Peyton, EL AF Lourenco-De-Oliveira, R Harbach, RE Castro, MG Motta, MA Peyton, EL TI Wyeomyia (Prosopolepis) confusa (Lutz): Subgeneric validation, species description, and recognition of Wyeomyia flui (Bonne-Wepster and Bonne) as the senior synonym of Wyeomyia kerri del Ponte and Cerqueira SO JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION LA English DT Article DE Culicidae; Wyeomyia; Prosopolepis; Wyeomyia confusa; Wyeomyia flui; Wyeomyia kerri ID MOSQUITOS DIPTERA; ANTHROPIC ENVIRONMENT; DENDROMYIA THEOBALD; SOUTH-EASTERN; CULICIDAE; BRAZIL AB Prosopolepis Lutz is validated as a monotypic subgenus of Wyeomyia Theobald and the type species, Weomyia confusa (Lutz), is redescribed. The description includes illustrations of the male and female genitalia, the 4th-stage larva, and the pupa. Prosopolepis flui Bonne-Wepster and Bonne is resurrected from synonymy with Wy. confusa and recognized as the senior synonym of Wyeomyia kerri del Ponte and Cerqueira. Wyeomyia flui does not belong in the subgenus Prosopolepis and remains in the genus Wyeomyia without subgeneric placement. Trichoprosopon pusillum Lutz and Nunez-Tovar is not synonymous with Wy. confusa and is provisionally regarded as a nomen dubium within Wyeomyia. The identity of Wy, confusa is fixed by neotype selection. C1 Inst Oswaldo Cruz, Lab Transmissores Hematozoarios, BR-21045900 Rio De Janeiro, Brazil. Nat Hist Museum, Dept Entomol, London SW7 5BD, England. Smithsonian Inst, Museum Supoort Ctr, Walter Reed Biosyst Unit, Washington, DC 20560 USA. RP Lourenco-De-Oliveira, R (reprint author), Inst Oswaldo Cruz, Lab Transmissores Hematozoarios, Av Brasil 4365, BR-21045900 Rio De Janeiro, Brazil. NR 50 TC 7 Z9 7 U1 0 U2 0 PU AMER MOSQUITO CONTROL ASSOC PI MOUNT LAUREL PA 15000 COMMERCE PARKWAY, SUITE C, MOUNT LAUREL, NJ 08054 USA SN 8756-971X EI 1943-6270 J9 J AM MOSQUITO CONTR JI J. Am. Mosq. Control Assoc. PD JUN PY 1999 VL 15 IS 2 BP 200 EP 212 PG 13 WC Entomology SC Entomology GA 212MF UT WOS:000081219900013 PM 10412115 ER PT J AU Peyton, EL Campbell, SR Candeletti, TM Romanowski, M Crans, WJ AF Peyton, EL Campbell, SR Candeletti, TM Romanowski, M Crans, WJ TI Aedes (Finlaya) japonicus japonicus (Theobald), a new introduction into the United States SO JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION LA English DT Article DE Aedes japonicus japonicus; United States; 1st record; bionomics; illustrations of adult and larva AB Aedes (Finlaya) japonicus japonicus is recorded for the Ist lime in the United States. Four adult females were collected in light traps at 2 sites in New York and one site in New Jersey during the months of August and September 1998. Notes on bionomics are provided. illustrations of the adult female, male, and larva are included. C1 Smithsonian Inst, Museum Support Ctr, Walter Reed Biosystemat Unit, Washington, DC 20560 USA. Suffolk Cty Dept Hlth Serv, Entomol Lab, Yaphank, NY 11980 USA. Ocean Cty Mosquito Extermnat Commiss, Barnegat, NJ 08005 USA. Rutgers State Univ, Dept Entomol, New Brunswick, NJ 08901 USA. RP Peyton, EL (reprint author), Smithsonian Inst, Museum Support Ctr, Walter Reed Biosystemat Unit, Washington, DC 20560 USA. NR 10 TC 120 Z9 123 U1 1 U2 7 PU AMER MOSQUITO CONTROL ASSN INC PI LAKE CHARLES PA 2200 E PRIEN LAKE RD, LAKE CHARLES, LA 70601 USA SN 8756-971X J9 J AM MOSQUITO CONTR JI J. Am. Mosq. Control Assoc. PD JUN PY 1999 VL 15 IS 2 BP 238 EP 241 PG 4 WC Entomology SC Entomology GA 212MF UT WOS:000081219900017 PM 10412119 ER PT J AU Polhemus, DA AF Polhemus, DA TI Names proposed and taxonomic publications by John T. Polhemus, 1964-1998 SO JOURNAL OF THE NEW YORK ENTOMOLOGICAL SOCIETY LA English DT Article AB A list of taxonomic names proposed, with designated holotype repositories, and a bibliography are presented for John T. Polhemus for the years 1964 to 1998 inclusive. Appendices are provided listing names proposed in honor of John T. Polhemus, and explaining holotype repository codons. C1 Smithsonian Inst, Dept Entomol, Washington, DC 20560 USA. RP Polhemus, DA (reprint author), Smithsonian Inst, Dept Entomol, MRC 105, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NEW YORK ENTOMOLOGICAL SOC INC PI NEW YORK PA C/O AMER MUSEUM NAT HIST 79TH & CENTRAL PARK WEST, NEW YORK, NY 10024 USA SN 0028-7199 J9 J NEW YORK ENTOMOL S JI J. N.Y. Entomol. Soc. PD SUM-FAL PY 1999 VL 107 IS 2-3 BP 99 EP 123 PG 25 WC Entomology SC Entomology GA 290UD UT WOS:000085695500003 ER PT J AU Schwartz, MD Polhemus, DA AF Schwartz, MD Polhemus, DA TI Asteliamiris, a new genus of Stenodemini from the Hawaiian Islands (Heteroptera : Miridae) SO JOURNAL OF THE NEW YORK ENTOMOLOGICAL SOCIETY LA English DT Article AB Asteliamiris johnpolhemi, a new genus and new species of stenodemine Miridae, is described from the island of Maul, in the Hawaiian Islands. Unlike most members of the Stenodemini which breed on grasses or sedges, both nymphal and adult stages of A. johnpolhemi are associated with Astelia menziesiana Smith, a member of the Liliaeceae. Dorsal habitus photographs, scanning electron micrographs of the head, scent gland efferent system, and pretarsus, illustrations of the male and female genitalia, and a distribution map are provided. C1 Agr & Agri Food Canada, Ctr Land & Biol Resources Res, Biol Resources Program, Amer Museum Nat Hist,Dept Entomol, Ottawa, ON K1A 0C6, Canada. Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, Washington, DC 20560 USA. RP Schwartz, MD (reprint author), Agr & Agri Food Canada, Ctr Land & Biol Resources Res, Biol Resources Program, Amer Museum Nat Hist,Dept Entomol, Ottawa, ON K1A 0C6, Canada. NR 6 TC 1 Z9 1 U1 0 U2 0 PU NEW YORK ENTOMOLOGICAL SOC INC PI NEW YORK PA C/O AMER MUSEUM NAT HIST 79TH & CENTRAL PARK WEST, NEW YORK, NY 10024 USA SN 0028-7199 J9 J NEW YORK ENTOMOL S JI J. N.Y. Entomol. Soc. PD SUM-FAL PY 1999 VL 107 IS 2-3 BP 154 EP 163 PG 10 WC Entomology SC Entomology GA 290UD UT WOS:000085695500008 ER PT J AU Polhemus, DA AF Polhemus, DA TI Naucoridae (Heteroptera) of New Guinea. 5. A review of Tanycricos La Rivers in Irian Jaya, with descriptions of two new species SO JOURNAL OF THE NEW YORK ENTOMOLOGICAL SOCIETY LA English DT Article AB Two new species of Tanycricos are described and illustrated from the Indonesian province of Irian Jaya, comprising western New Guinea: T. jaetipi n. sp. and T. ziwa n. sp., both from the upper Wapoga River basin. Additional records are given for previously described species of Tanycricos in Irian Jaya, and island wide distribution maps are provided for all species in the genus. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, Washington, DC 20560 USA. RP Polhemus, DA (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, MRC 105, Washington, DC 20560 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU NEW YORK ENTOMOLOGICAL SOC INC PI NEW YORK PA C/O AMER MUSEUM NAT HIST 79TH & CENTRAL PARK WEST, NEW YORK, NY 10024 USA SN 0028-7199 J9 J NEW YORK ENTOMOL S JI J. N.Y. Entomol. Soc. PD SUM-FAL PY 1999 VL 107 IS 2-3 BP 171 EP 180 PG 10 WC Entomology SC Entomology GA 290UD UT WOS:000085695500010 ER PT J AU Kaeppler, AL AF Kaeppler, AL TI Kie hingoa: Mats of power, rank, prestige and history SO JOURNAL OF THE POLYNESIAN SOCIETY LA English DT Article; Proceedings Paper CT Annual Meeting of the Association-for-Social-Anthropology-in-Oceania CY 1996 CL KONA, HAWAII SP Assoc Social Anthr C1 Smithsonian Inst, Washington, DC 20560 USA. RP Kaeppler, AL (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 25 TC 14 Z9 15 U1 0 U2 1 PU POLYNESIAN SOC INC PI AUCKLAND PA C/O UNIV AUCKLAND, DEPT ANTHROPOLOGY, PRIVATE BAG, AUCKLAND 92019, NEW ZEALAND SN 0032-4000 J9 J POLYNESIAN SOC JI J. Polyn. Soc. PD JUN PY 1999 VL 108 IS 2 BP 168 EP 232 PG 65 WC Anthropology SC Anthropology GA 274QP UT WOS:000084776800003 ER PT J AU Raymond, JT White, MR AF Raymond, JT White, MR TI Necropsy and histopathologic findings in 14 African hedgehogs (Atelerix albiventris): A retrospective study SO JOURNAL OF ZOO AND WILDLIFE MEDICINE LA English DT Article DE hedgehog; Atelerix albiventris; hepatic lipidosis; splenic extramedullary hematopoiesis; neoplasia ID MOLECULES AB From fiscal years 1992 through 1996, 14 African hedgehog (Atelerix albiventris) cases were submitted to the Animal Disease Diagnostic Laboratory at Purdue University. The most common diagnoses were splenic extramedullary hematopoiesis (91%), hepatic lipidosis (50%), renal disease (50%), and neoplastic disease (29%). Other less frequent necropsy findings were myocarditis (21%), colitis (14%), bacterial septicemia (14%), and pneumonia (14%). The data indicate that splenic extramedullary hematopoiesis, hepatic lipidosis, renal disease, and neoplasms are frequent postmortem findings in hedgehogs. C1 Purdue Univ, Anim Dis Diagnost Lab, W Lafayette, IN 47906 USA. RP Raymond, JT (reprint author), Smithsonian Inst, Natl Zool Pk, Dept Pathol, 3000 Connecticut Ave NW, Washington, DC 20008 USA. NR 32 TC 37 Z9 38 U1 0 U2 6 PU AMER ASSOC ZOO VETERINARIANS PI MEDIA PA 6 NORTH PENNELL ROAD, MEDIA, PA 19063 USA SN 1042-7260 J9 J ZOO WILDLIFE MED JI J. Zoo Wildl. Med. PD JUN PY 1999 VL 30 IS 2 BP 273 EP 277 PG 5 WC Veterinary Sciences SC Veterinary Sciences GA 219LC UT WOS:000081607900012 PM 10484145 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI Twilight of the intellectuals. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Lib, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD JUN 1 PY 1999 VL 124 IS 10 BP 137 EP 137 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 201GY UT WOS:000080588100134 ER PT J AU Tarr, CL Fleischer, RC AF Tarr, CL Fleischer, RC TI Population boundaries and genetic diversity in the endangered Mariana crow (Corvus kubaryi) SO MOLECULAR ECOLOGY LA English DT Article DE conservation genetics; ESU; island birds; microsatellites; minisatellites; mtDNA control region ID MITOCHONDRIAL CONTROL-REGION; CONSERVATION GENETICS; FLORIDA PANTHER; DNA; SEQUENCES; BOTTLENECK; DISTANCE; DIFFERENTIATION; MICROSATELLITES; VARIABILITY AB The Mariana crow (Corvus kubaryi) is an endangered species that is restricted to the islands of Guam and Rota in the Mariana archipelago. Predation by the introduced brown tree snake (Boiga irregularis) has decimated bird populations on Guam, and the crow population there is the last wild remnant of the endemic forest avifauna. The population on Guam is critically endangered and, despite intensive management, the population has continued to decline. Additional management options include intermixing the Guam and Rota populations, but such options are best evaluated within a population genetics framework. We used three types of molecular markers to assay genetic variation in the Mariana crow: mitochondrial DNA (mtDNA) sequences, minisatellites and microsatellites. The two populations could be differentiated by mtDNA sequencing and they differed in allele frequencies at nuclear markers. Thus, the populations could be designated as evolutionarily significant units. However, the Guam population is genetically more diverse than the Rota population, and its survival probability if managed separately is very low. All markers did indicate that the two populations are closely related and separated by a shallow genealogical division. Intermixing the populations is justified by two rationales. First, the apparent population differences may result from recent human activities. Second, a greater amount of genetic information may be preserved by joint management. The translocation of birds from Rota to Guam has begun, but strategies that will ensure maintenance of the variation in the Guam population warrant further exploration. C1 Penn State Univ, Dept Biol, University Pk, PA 16802 USA. Penn State Univ, Inst Mol Evolut Genet, University Pk, PA 16802 USA. Smithsonian Inst, Natl Zool Pk, Mol Genet Lab, Washington, DC 20008 USA. RP Tarr, CL (reprint author), Penn State Univ, Dept Biol, 208 Mueller Lab, University Pk, PA 16802 USA. NR 68 TC 26 Z9 29 U1 4 U2 20 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD JUN PY 1999 VL 8 IS 6 BP 941 EP 949 DI 10.1046/j.1365-294x.1999.00644.x PG 9 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 219UE UT WOS:000081624800004 PM 10434415 ER PT J AU Wagner, WL AF Wagner, WL TI Nomenclator and review of Phyllostegia (Lamiaceae) SO NOVON LA English DT Article AB In 1987 Harold St. John published 93 names in Hawaiian Phyllostegia and 1 in Tonga; only 3 of them were accounted for in the most recent taxonomic revision of the Hawaiian species by Wagner et al, in 1990. The types of these names are analyzed, and the names are here incorporated into the current classification. Only five of the new Hawaiian species are here recognized as distinct (P. kaalaensis, P. kahiliensis, P. micrantha, P. pilosa, and P. warshaueri), and one of the new combinations is accepted here (P. velutina), with the remainder here placed into the synonymy of other species. Five of the names were not validly published. The complete nomenclature of Phyllostegia at the species level and below is presented, including 181 names. A total of 32 Hawaiian Phyllostegia species are currently recognized, including the 5 recognized St. John species published in 1987 and 2 others, P. haliakalae, resurrected from the synonymy of P. mollis, and P. renovans, discovered in 1989. The five Hawaiian species not treated in the 1990 revision are briefly characterized and discussed. Notes adding information on taxonomy, distribution, and population and conservation status not included in the recent treatment also are given. The genus also is known from Tahiti and Tonga, each with one species; the nomenclature for these two species is included, but they are not evaluated in this paper. C1 Smithsonian Inst, Dept Bot, Washington, DC 20560 USA. RP Wagner, WL (reprint author), Smithsonian Inst, Dept Bot, MRC 166, Washington, DC 20560 USA. NR 28 TC 7 Z9 8 U1 0 U2 1 PU MISSOURI BOTANICAL GARDEN PI ST LOUIS PA 2345 TOWER GROVE AVENUE, ST LOUIS, MO 63110 USA SN 1055-3177 J9 NOVON JI Novon PD SUM PY 1999 VL 9 IS 2 BP 265 EP 279 DI 10.2307/3391814 PG 15 WC Plant Sciences SC Plant Sciences GA 201GV UT WOS:000080587800031 ER PT J AU Cutler, AH Behrensmeyer, AK Chapman, RE AF Cutler, AH Behrensmeyer, AK Chapman, RE TI Environmental information in a recent bone assemblage: roles of taphonomic processes and ecological change SO PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY LA English DT Article DE taphonomy; paleoenvironments; mammals; Africa ID PALEOECOLOGY; PATTERNS; ANTELOPE AB Taphonomic processes have the potential to obscure or enhance original associations between paleoenvironments and organisms through selective destruction, post-mortem transport, and time-averaging. Ecological changes through time in habitat utilization by living organisms also can blur distinctions between faunas or floras associated with particular habitats. If taphonomic processes affect habitat specificity in bone assemblages, then this should be revealed in time sequences of remains from particular habitats. We analyzed Recent surface bone in six habitats of Amboseli National Park, Kenya, to determine whether taxonomic composition varied with the degree of taphonomic alteration las indicated by bent: weathering stage). The dataset consisted of 1362 separate bone occurrences classified according to their state of weathering. These bone occurrences represented 27 mammalian taxa from bush, openwood, densewood, lakebed, plains, and swamp habitats. The distinctiveness of the bone assemblages was measured by the quantified Dice coefficient, which accounts for both the presence or absence of taxa and their relative proportions. The differences among the weathering stage subsamples were compared with known environmental changes at Amboseli over the estimated time period of bone accumulation (15-25 years). Habitat distinctiveness based on the bunt: assemblages was lower in subsets with higher weathering stages, although not all habitats showed this to the same degree, and open habitats (e.g., plains, lakebed) generally remained distinct from closed habitats (densewood, bush). The greatest change in the similarity among habitats occurred between weathering stages 2 and 3, which corresponds to deaths between 1969 and 1973, a period of woodland retreat and expansion of open habitats in the park. We attribute the loss of environmental resolution in the weathered bone subsamples primarily to time-averaging and the shifting of habitat boundaries. The time period represented by these bone assemblages is small compared to the time-averaged paleosol or land surface assemblages in the fossil record, suggesting that ecological fluctuations can compromise interpretations of habitat heterogeneity in fossil assemblages. Our study indicates that it is probably the magnitude of ecological changes rather than time per se that limits resolution. If distinct paleohabitats can be supported based on time-averaged fossil evidence, however, this implies that ecological fluctuations were not sufficient to homogenize these distinctions over the period of time-averaging. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Paleobiol, Washington, DC 20560 USA. Smithsonian Inst, Museum Natl Hist Nat, Appl Morphometr Lab, Washington, DC 20560 USA. RP Cutler, AH (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Dept Paleobiol, MRC-121, Washington, DC 20560 USA. NR 27 TC 28 Z9 30 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-0182 J9 PALAEOGEOGR PALAEOCL JI Paleogeogr. Paleoclimatol. Paleoecol. PD JUN 1 PY 1999 VL 149 IS 1-4 BP 359 EP 372 DI 10.1016/S0031-0182(98)00212-0 PG 14 WC Geography, Physical; Geosciences, Multidisciplinary; Paleontology SC Physical Geography; Geology; Paleontology GA 208ZX UT WOS:000081023500026 ER PT J AU Hayes, DR Brinley, W Goodrich, VR Neale, PJ AF Hayes, DR Brinley, W Goodrich, VR Neale, PJ TI High resolution measurements of spectral UV-B using the Smithsonian Institution 18 channel multifilter radiometer. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RI Neale, Patrick/A-3683-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 79S EP 79S PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200236 ER PT J AU Neale, PJ Hayes, DR Goodrich, VR Brinley, W AF Neale, PJ Hayes, DR Goodrich, VR Brinley, W TI Biologically effective UV in the mid-Atlantic region, 1975-1997. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RI Neale, Patrick/A-3683-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 79S EP 79S PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200238 ER PT J AU Neale, PJ Fritz, JJ Davis, RF Peloquin, JA AF Neale, PJ Fritz, JJ Davis, RF Peloquin, JA TI Effects of ultraviolet radiation on photosynthesis by antarctic phytoplankton SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RI Neale, Patrick/A-3683-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 92S EP 93S PG 2 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200280 ER PT J AU Naraschewski, M Glauber, RJ AF Naraschewski, M Glauber, RJ TI Spatial coherence and density correlations of trapped Bose gases SO PHYSICAL REVIEW A LA English DT Article ID EINSTEIN CONDENSATION; QUANTUM PHASE; INTERFERENCE; FLUCTUATIONS; COLLISIONS; ATOMS AB We study first- and second-order coherence of trapped dilute Bose gases using appropriate correlation functions. Special attention is given to the discussion of second-order or density correlations. Except for a small region around the surface of a Bose-Einstein condensate the correlations can be accurately described as those of a locally homogeneous gas with a spatially varying chemical potential. The degrees of first- and second-order coherence are therefore functions of temperature, chemical potential, and position. The second-order correlation function is governed both by the tendency of bosonic atoms to cluster and by a strong repulsion at small distances due to atomic interactions. In present experiments both effects are of comparable magnitude. Below the critical temperature the range of the bosonic correlation is affected by the presence of collective quasiparticle excitations. The results of some recent experiments on second- and third-order coherence are discussed. It is shown that the relation between the measured quantities and the correlation functions is much weaker than previously assumed. [S1050-2947(99)04405-4]. C1 Harvard Univ, Dept Phys, Jefferson Lab, Cambridge, MA 02138 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Harvard Univ, Dept Phys, Lyman Lab Phys, Cambridge, MA 02138 USA. RP Naraschewski, M (reprint author), Harvard Univ, Dept Phys, Jefferson Lab, Cambridge, MA 02138 USA. NR 34 TC 154 Z9 155 U1 2 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1999 VL 59 IS 6 BP 4595 EP 4607 DI 10.1103/PhysRevA.59.4595 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 204RH UT WOS:000080777600061 ER PT J AU Janzen, PH Gardner, LD Reisenfeld, DB Savin, DW Kohl, JL Bartschat, K AF Janzen, PH Gardner, LD Reisenfeld, DB Savin, DW Kohl, JL Bartschat, K TI Reevaluation of experiments and new theoretical calculations for electron-impact excitation of C3+ SO PHYSICAL REVIEW A LA English DT Article ID ABSOLUTE CROSS-SECTIONS; DIELECTRONIC RECOMBINATION; 2S-2P EXCITATION; MAGNETIC-FIELDS; IONIZATION; IONS AB Experimental absolute-rate coefficients for electron-impact excitation of C3+ (2s(2)S(1/2) --> 2p(2)P(1/2,3/2)) near threshold [D. W. Savin, L. D. Gardner, D. B. Reisenfeld, A. R. Young, and J. L. Kohl, Phys. Rev. A 51, 2162 (1995)] have been reanalyzed to include a more accurate determination of optical efficiency acid revised radiometric uncertainties which reduce the total systematic uncertainty of the results. Also, new R matrix with pseudostates (RMPS) calculations for this transition near threshold are presented. Comparison of the RMPS results to those of simpler close-coupling calculations indicates the importance of accounting for target continuum effects. The reanalyzed results of Savin et al. are in excellent agreement with the RMPS calculations; comparisons are also made to other measurements of this excitation. Agreement with the RMPS results is better for fluorescence technique measurements than for electron-energy-loss measurements. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Drake Univ, Dept Phys & Astron, Des Moines, IA 50311 USA. RP Janzen, PH (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Bartschat, Klaus/I-2527-2012; Savin, Daniel/B-9576-2012; Reisenfeld, Daniel/F-7614-2015 OI Savin, Daniel/0000-0002-1111-6610; NR 19 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1999 VL 59 IS 6 BP 4821 EP 4824 DI 10.1103/PhysRevA.59.4821 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 204RH UT WOS:000080777600093 ER PT J AU Drake, BG Azcon-Bieto, J Berry, J Bunce, J Dijkstra, P Farrar, J Gifford, RM Gonzalez-Meler, MA Koch, G Lambers, H Siedow, J Wullschleger, S AF Drake, BG Azcon-Bieto, J Berry, J Bunce, J Dijkstra, P Farrar, J Gifford, RM Gonzalez-Meler, MA Koch, G Lambers, H Siedow, J Wullschleger, S TI Does elevated atmospheric CO2 concentration inhibit mitochondrial respiration in green plants? SO PLANT CELL AND ENVIRONMENT LA English DT Article; Proceedings Paper CT Smithsonian Environmental Research Center Workshop CY JAN 08-09, 1998 CL EDGEWATER, MARYLAND DE acclimation to rising CO2; dark respiration; global carbon cycle; rising CO2 ID CARBON-DIOXIDE CONCENTRATION; DARK RESPIRATION; MAINTENANCE RESPIRATION; CHEMICAL-COMPOSITION; CONSTRUCTION COSTS; LEAF RESPIRATION; LOLIUM-PERENNE; WHEAT LEAVES; GAS-EXCHANGE; GROWTH AB There is abundant evidence that a reduction in mitochondrial respiration of plants occurs when atmospheric CO2 (C-a) is increased. Recent reviews suggest that doubling the present C-a will reduce the respiration rate [per unit dry weight (DW)] by 15 to 18%. The effect has two components: an immediate, reversible effect observed in leaves, stems, and roots of plants as well as soil microbes, and an irreversible effect which occurs as a consequence of growth in elevated C-a and appears to be specific to C-3 species. The direct effect has been correlated with inhibition of certain respiratory enzymes, namely cytochrome-c-oxidase and succinate dehydrogenase, and the indirect or acclimation effect may be related to changes in tissue composition. Although no satisfactory mechanisms to explain these effects have been demonstrated, plausible mechanisms have been proposed and await experimental testing. These are carbamylation of proteins and direct inhibition of enzymes of respiration. A reduction of foliar respiration of 15% by doubling present ambient C-a would represent 3 Gt of carbon per annum in the global carbon budget. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Univ Barcelona, Fac Biol, Dept Biol Vegetal, E-08028 Barcelona, Spain. Carnegie Inst Washington, Dept Plant Biol, Stanford, CA 94305 USA. ARS, USDA, Climate Stress Lab, Beltsville, MD 20705 USA. Univ Coll N Wales, Sch Biol Sci, Bangor LL57 2UW, Gwynedd, Wales. CSIRO, Canberra, ACT 2601, Australia. Duke Univ, Dept Bot, Dev Cell & Mol Biol Grp, Durham, NC 27708 USA. No Arizona Univ, Dept Biol Sci, Flagstaff, AZ 86011 USA. Univ Utrecht, Dept Plant Ecol & Evolut Biol, NL-3584 CA Utrecht, Netherlands. Duke Univ, Durham, NC USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Drake, BG (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. RI Berry, Joseph/B-8211-2009; Wullschleger, Stan/B-8297-2012; Lambers, Hans/A-1544-2008; OI Berry, Joseph/0000-0002-5849-6438; Wullschleger, Stan/0000-0002-9869-0446; Lambers, Hans/0000-0002-4118-2272; Gonzalez-Meler, Miquel/0000-0001-5388-7969 NR 65 TC 105 Z9 115 U1 1 U2 20 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0140-7791 J9 PLANT CELL ENVIRON JI Plant Cell Environ. PD JUN PY 1999 VL 22 IS 6 BP 649 EP 657 DI 10.1046/j.1365-3040.1999.00438.x PG 9 WC Plant Sciences SC Plant Sciences GA 217VW UT WOS:000081520500007 ER PT J AU Jackman, TR Larson, A de Queiroz, K Losos, JB AF Jackman, TR Larson, A de Queiroz, K Losos, JB TI Phylogenetic relationships and tempo of early diversification in Anolis lizards SO SYSTEMATIC BIOLOGY LA English DT Article DE Anolis; mitochondrial DNA; parametric bootstrap; permutation test; phylogeny; polytomy ID TRANSFER-RNA GENES; MITOCHONDRIAL GENOME; PERMUTATION TESTS; CONFIDENCE-LIMITS; DNA-SEQUENCES; EVOLUTION; IGUANIDAE; ISLANDS; COLONIZATION; SYSTEMATICS AB We examine phylogenetic relationships among anoles using mitochondrial DNA sequences from the NADH dehydrogenase subunit 2 gene (ND2) and five transfer RNA genes representing 1,455 alignable base positions and 866 phylogenetically informative characters (parsimony criterion). We also present 16 morphological characters for phylogenetic analysis. Our analyses yielded poorly-supported nodes deep in the anole tree but many well-supported nodes for more recent phylogenetic divergences. We test the hypothesis that the major clades of anoles form a hard polytomy and present a general statistical framework for testing hypotheses of simultaneous branching of lineages by using molecular sequence data. Our results suggest that rapid diversification early in the evolutionary history of anoles explains why numerous researchers have had difficulty reconstructing well-supported dichotomous phylogenetic trees for anoles. C1 Washington Univ, Dept Biol, St Louis, MO 63130 USA. Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. RP Jackman, TR (reprint author), Washington Univ, Dept Biol, Campus Box 1137, St Louis, MO 63130 USA. OI Jackman, Todd/0000-0002-5391-8136 NR 71 TC 179 Z9 184 U1 6 U2 22 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 1063-5157 J9 SYST BIOL JI Syst. Biol. PD JUN PY 1999 VL 48 IS 2 BP 254 EP 285 PG 32 WC Evolutionary Biology SC Evolutionary Biology GA 210KD UT WOS:000081103200002 ER PT J AU Wagstaff, DJ Lellinger, DB Wiersema, JH AF Wagstaff, DJ Lellinger, DB Wiersema, JH TI Retrospective searching for poisonous plant vouchers SO VETERINARY AND HUMAN TOXICOLOGY LA English DT Review AB Few published reports of plant poisoning, whether experimental or accidental, document vouchers. This can be rectified by retrospective location of vouchers through determination of a collaborating-botanist or herbarium of deposit. An absolute voucher is referenced in the toxicology-report. For a probable voucher the report does not identify an herbarium specimen, but the report and the specimen label or sheet agree on plant name; collector's name, collection date and place. A possible voucher is perhaps from the exposure lot, but was collected by the collaborating botanist at a somewhat earlier or later date than the exposure date. On the other hand, a supporting specimen was collected by the collaborating botanist but is not from the exposure lot. Vouchers and supporting specimens for some species of Asclepias tested for toxicity by CD Marsh and coworkers were found in the US National Herbarium at the Smithsonian Institution, Washington DC. C1 US Natl Herbarium, Smithsonian Inst, Washington, DC 20560 USA. USDA ARS, Beltsville Agr Res Ctr W, Systemat Bot & Mycol Lab, Beltsville, MD 20705 USA. RP Wagstaff, DJ (reprint author), 177 S 200 E, Orem, UT 84058 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU COMPARATIVE TOXICOLOGY LAB PI MANHATTAN PA KANSAS STATE UNIV, MANHATTAN, KS 66506-5606 USA SN 0145-6296 J9 VET HUM TOXICOL JI Vet. Human Toxicol. PD JUN PY 1999 VL 41 IS 3 BP 158 EP 161 PG 4 WC Toxicology; Veterinary Sciences SC Toxicology; Veterinary Sciences GA 197QA UT WOS:000080375300009 PM 10349707 ER PT J AU Wagstaff, DJ Wiersema, JH Lellinger, DB AF Wagstaff, DJ Wiersema, JH Lellinger, DB TI Poisonous plant vouchers SO VETERINARY AND HUMAN TOXICOLOGY LA English DT Article AB Every published report of plant poisoning, whether experimental or accidental, should document plant identification. The essential elements are: complete botanical Latin name including species, specific epithet and author(s); name:of the collaborating botanist who identified the plant; and herbarium and collection number of a voucher specimen from the exposure lot. Additional information to aid identification might include plant photographs; drawings, and descriptions. C1 USDA ARS, Beltsville Agr Res Ctr W, Systemat Bot & Mycol Lab, Beltsville, MD 20705 USA. US Nalt Herbarium, Smithsonian Inst, Washington, DC 20560 USA. RP Wagstaff, DJ (reprint author), 177 S 200 E, Orem, UT 84058 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU COMPARATIVE TOXICOLOGY LAB PI MANHATTAN PA KANSAS STATE UNIV, MANHATTAN, KS 66506-5606 USA SN 0145-6296 J9 VET HUM TOXICOL JI Vet. Human Toxicol. PD JUN PY 1999 VL 41 IS 3 BP 162 EP 164 PG 3 WC Toxicology; Veterinary Sciences SC Toxicology; Veterinary Sciences GA 197QA UT WOS:000080375300010 PM 10349708 ER PT J AU Krabbe, N Isler, ML Isler, PR Whitney, BM Alvarez, J Greenfield, PJ AF Krabbe, N Isler, ML Isler, PR Whitney, BM Alvarez, J Greenfield, PJ TI A new species in the Myrmotherula haematonota superspecies (Aves; Thamnophilidae) from the western Amazonian lowlands of Ecuador and Peru SO WILSON BULLETIN LA English DT Article ID VOCALIZATIONS; BEHAVIOR; ANTWRENS AB A new species of antwren (Myrmotherula fjeldsaai) closely related to Myrmotherula haematonota is described from the lower tropical zone of eastern Ecuador and immediately adjacent Peru. It primarily differs from M, h, haematonota by its brown instead of red back in both sexes. New distributional data for nominate M. h. haematonota shows that it meets the new species north of the Rio Maranon, between the Rios Nape and Pastaza, with no apparently significant physical barrier between them. C1 Smithsonian Inst, Natl Museum Nat Hist, Div Birds, Washington, DC 20560 USA. Louisiana State Univ, Museum Nat Sci, Baton Rouge, LA 70803 USA. Inst Invest Amazonia Peruana, Iquitos, Peru. Univ Copenhagen, Zool Museum, DK-2100 Copenhagen, Denmark. RP Krabbe, N (reprint author), Cas 17-21-791, Quito, Ecuador. EM NKrabbe@pi.pro.ec NR 16 TC 5 Z9 6 U1 0 U2 2 PU WILSON ORNITHOLOGICAL SOC PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710 USA SN 0043-5643 J9 WILSON BULL JI Wilson Bull. PD JUN PY 1999 VL 111 IS 2 BP 157 EP + PG 10 WC Ornithology SC Zoology GA 197PB UT WOS:000080372700001 ER PT J AU Winker, K Weiss, SA Trejo, JL Escalante, P AF Winker, K Weiss, SA Trejo, JL Escalante, P TI Notes on the avifauna of Tabasco SO WILSON BULLETIN LA English DT Article AB Tabasco, a Mexican state nearly half the size of the country of Costa Rica, lies juxtaposed between the Isthmus of Tehuantepec and the Yucatan Peninsula. This state hosts a diverse Neotropical resident avifauna, is a significant wintering area for Nearctic-Neotropic migrants, and has important biogeographic significance. Surprisingly little recent ornithological study has occurred in Tabasco; the last major publication treats data from 1939, Field work in March 1996 and recent specimens add nine species to the state list: Caprimulgus vociferus, Chaetura vauxi, Campylopterus excellens, Empidonax albigularis, Thryothorus modestus, Turdus infuscatus, Myadestes unicolor, Limnothlypis swainsonii, and Vermivora ruficapilla. The status of 26 other species is discussed. Further evidence of lowland forests being used as temporary refugia by birds from higher elevations is also considered. C1 Smithsonian Inst, NZP, Conservat & Res Ctr, Front Royal, VA 22630 USA. Univ Juarez Autonoma Tabasco, Div Acad Ciencias Biol, Villahermosa 86000, Tabasco, Mexico. Univ Nacl Autonoma Mexico, Inst Biol, Dept Zool, Mexico City 04510, DF, Mexico. RP Winker, K (reprint author), Univ Alaska Museum, 907 Yukon Dr, Fairbanks, AK 99775 USA. RI Winker, Kevin/M-2042-2014; Escalante, Patricia/B-8704-2014 OI Winker, Kevin/0000-0002-8985-8104; Escalante, Patricia/0000-0002-5531-263X NR 12 TC 5 Z9 8 U1 0 U2 4 PU WILSON ORNITHOLOGICAL SOC PI ANN ARBOR PA MUSEUM OF ZOOLOGY UNIV MICHIGAN, ANN ARBOR, MI 48109 USA SN 0043-5643 J9 WILSON BULL JI Wilson Bull. PD JUN PY 1999 VL 111 IS 2 BP 229 EP 235 PG 7 WC Ornithology SC Zoology GA 197PB UT WOS:000080372700008 ER PT J AU Angehr, GR AF Angehr, GR TI Rapid long-distance colonization of Lake Gatun, Panama, by Snail Kites SO WILSON BULLETIN LA English DT Article ID MATE DESERTION; WATER LEVELS; FLORIDA; DEMOGRAPHY AB The distribution of the Snail Kite (Rostrhamus sociabilis) is closely tied to that of apple snails (Pomacea spp.), its nearly exclusive food. Before the early 1990s, the species occurred in Panama primarily as a vagrant. Apple snails were introduced to Lake Gatun in central Panama in the late 1980s, and by 1994 Snail Kites had colonized the lake from population sources at least 350 km away and initiated breeding. Since 1994 the population has increased rapidly and the species can now be found throughout the lake. C1 Smithsonian Trop Res Inst, APO, AA 34002 USA. RP Angehr, GR (reprint author), Smithsonian Trop Res Inst, Unit 0948, APO, AA 34002 USA. EM angehrg@tivoli.si.edu NR 20 TC 7 Z9 9 U1 0 U2 1 PU WILSON ORNITHOLOGICAL SOC PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710 USA SN 0043-5643 J9 WILSON BULL JI Wilson Bull. PD JUN PY 1999 VL 111 IS 2 BP 265 EP 268 PG 4 WC Ornithology SC Zoology GA 197PB UT WOS:000080372700014 ER PT J AU Wagner, AP AF Wagner, AP TI Adirondack prints and printmakers: The call of the wild SO WINTERTHUR PORTFOLIO-A JOURNAL OF AMERICAN MATERIAL CULTURE LA English DT Book Review C1 Smithsonian Inst, Natl Portrait Gallery, Washington, DC 20560 USA. RP Wagner, AP (reprint author), Smithsonian Inst, Natl Portrait Gallery, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0084-0416 J9 WINTERTHUR PORTFOLIO JI Winterthur Portfol.-J. Amer. Mater. Cult. PD SUM-FAL PY 1999 VL 34 IS 2-3 BP 165 EP 168 DI 10.1086/496780 PG 4 WC Art SC Art GA 228TA UT WOS:000082150700008 ER PT J AU Taylor, L AF Taylor, L TI Mexican brick culture in the building of Texas, 1800s-1980s SO WINTERTHUR PORTFOLIO-A JOURNAL OF AMERICAN MATERIAL CULTURE LA English DT Book Review C1 Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. RP Taylor, L (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0084-0416 J9 WINTERTHUR PORTFOLIO JI Winterthur Portfol.-J. Amer. Mater. Cult. PD SUM-FAL PY 1999 VL 34 IS 2-3 BP 168 EP 172 DI 10.1086/496781 PG 5 WC Art SC Art GA 228TA UT WOS:000082150700009 ER PT J AU Smalley, GW Coats, DW Adam, EJ AF Smalley, GW Coats, DW Adam, EJ TI A new method using fluorescent microspheres to determine grazing on ciliates by the mixotrophic dinoflagellate Ceratium furca SO AQUATIC MICROBIAL ECOLOGY LA English DT Article DE Ceratium furca; mixotrophy; dinoflagellates; ciliates; fluorescent microspheres; Chesapeake Bay ID FRAGILIDIUM-SUBGLOBOSUM DINOPHYCEAE; LABELED ALGAE FLA; CHESAPEAKE BAY; LIGHT-INTENSITY; CLEARANCE RATES; PREY; PHAGOTROPHY; INGESTION; MARINE; PROTISTS AB Feeding in the mixotrophic dinoflagellate Ceratium furca was investigated using 1 mu m fluorescent microspheres to label prey. Microspheres added to natural plankton assemblages at a concentration of 5 x 10(6) to 10(7) ml(-1) were rapidly ingested by a variety of planktonic organisms including small flagellates, ciliates, dinoflagellates, ebriids and amoebae. Prey thus labeled were in turn phagocytized by C, furca and were easily detected within the predator using fluorescent microscopy. Ingestion rates were calculated by following the appearance of labeled food vacuoles in C. furca over time. C. furca did not ingest microspheres directly. and thus the calculated rates represented feeding on labeled prey only. Food vacuole contents and labeled prey were identified using a modified Protargol staining procedure that retained the integrity and fluorescent properties of the latex microspheres. Data on food vacuole content and potential prey availability indicated that C. furca preyed mainly an choreotrich ciliates (i.e. Strobilidium spp, and tintinnids) 10 to 40 mu m in diameter. In addition, feeding rates were strongly correlated with choreotrich densities and suggested that C, furca preferred ciliates of the genus Strobilidium. Ingestion rates of C. furca ranged from 0 to 0.11 prey h(-1), and varied greatly from one year to the next. Clearance rates ranged from 0 to 12.49 mu l (C. furca)(-1) h(-1), with an average of 2.1 +/- 0.41 ml (C. furca)(-1) h(-1). Both ingestion and clearance rates were comparable to rates previously reported for mixotrophic and heterotrophic dinoflagellates. The method presented here has several advantages for the study of mixotrophy in large, slow-feeding dinoflagellates. Live prey found in natural water samples are used, and surface characteristics of prey remain unaltered. No addition of prey is necessary, and only a minimum amount of handling of the sample is required. Incubation experiments can last for 6 h, allowing sufficient time for the appearance of labeled food vacuoles in predators with low feeding rates. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Univ Maryland Syst, Ctr Environm Studies, Horn Point Lab, Cambridge, MD 21613 USA. RP Smalley, GW (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. EM smalley@serc.si.edu NR 48 TC 52 Z9 60 U1 0 U2 5 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0948-3055 EI 1616-1564 J9 AQUAT MICROB ECOL JI Aquat. Microb. Ecol. PD MAY 28 PY 1999 VL 17 IS 2 BP 167 EP 179 DI 10.3354/ame017167 PG 13 WC Ecology; Marine & Freshwater Biology; Microbiology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Microbiology GA 207GP UT WOS:000080928300007 ER PT J AU Shurgalin, M Murray, AJ MacGillivray, WR Standage, MC Madison, DH Winkler, KD Bray, I AF Shurgalin, M Murray, AJ MacGillivray, WR Standage, MC Madison, DH Winkler, KD Bray, I TI Atomic collision parameters for electron de-excitation of the 4S-3P transition of sodium SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID LASER-EXCITED ATOMS; DISTORTED-WAVE CALCULATION; OPTICALLY PUMPED SODIUM; SUPERELASTIC-SCATTERING; IMPACT EXCITATION; ORIENTATION; ALIGNMENT; STATES; NA(3P); ...6S5D(1)D(2) AB A comparison of measured Stokes parameters and atomic collision parameters (P-lin gamma, L-perpendicular to, P+) is made for the excitation and de-excitation of the 3S-3P and 4S-3P transitions of Na respectively, for electrons with incident energies of 22, 30 and 50 eV. These parameters are obtained from 'time-inverse' experiments in which electrons are either superelastically (3P-3S) or inelastically (3P-4S) scattered from the laser prepared 3P state, The data are compared with calculations from a convergent close coupling (CCC) model and a second-order distorted wave Born (DWB2) model. Both models demonstrate very good agreement for 3S-3P transitions. For the 4S-3P transitions, the DWB2 is in better accord with experiment than the CCC for the P-lin, parameter, the CCC is in excellent agreement with experiment for gamma and LI, and neither is in accord with experiment for P+. C1 Griffith Univ, Sch Sci, Laser Atom Phys Lab, Nathan, Qld 4111, Australia. Univ Missouri, Lab Atom Mol & Opt Res, Rolla, MO 65401 USA. Flinders Univ S Australia, Elect Struct Mat Ctr, Adelaide, SA 5001, Australia. RP Shurgalin, M (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Bray, Igor/B-8586-2009 OI Bray, Igor/0000-0001-7554-8044 NR 47 TC 11 Z9 11 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD MAY 28 PY 1999 VL 32 IS 10 BP 2439 EP 2459 DI 10.1088/0953-4075/32/10/312 PG 21 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 204EB UT WOS:000080749200014 ER PT J AU Imamura, H Knapp, LW AF Imamura, H Knapp, LW TI Thysanophrys papillaris, a new species of flathead from the Andaman Sea and northern Australia (Scorpaeniformes : Platycephalidae) SO ICHTHYOLOGICAL RESEARCH LA English DT Article DE Platycephalidae; Thysanophrys papillaris sp nov.; Andaman Sea; Timor Sea; Arafura Sea AB A new platycephalid Thysanophrys papillaris, is described on the basis of six specimens (78-121 mm SL) collected from the Andaman Sea and off northern Australia (Timor and Arafura Seas). This new species can be distinguished from other congeners by the following combination of characters: presence of a single short papilla on upper surface of eye, longer snout, smaller body scales, 11 second dorsal-fin rays and 12 anal-fin rays, presence of four or more suborbital spines usually, branched short iris lappet, ctenoid lateral-line scales and interopercle not extended posteroventrally. C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Vertebrate Zool, Washington, DC 20560 USA. Tohoku Natl Fisheries Res Inst, Hachinohe Branch, Fisheries Agcy, Hachinohe, Aomori 0310841, Japan. Natl Museum Nat Hist, Dept Vertebrate Zool, Smithsonian Inst, Washington, DC 20560 USA. RP Imamura, H (reprint author), Hokkaido Univ, Fac Fisheries, Fisheries Museum, 3-1-1 Minato Cho, Hakodate, Hokkaido 0418611, Japan. NR 7 TC 2 Z9 2 U1 0 U2 0 PU ICHTHYOLOGICAL SOC JAPAN PI TOKYO PA BUSINESS CENTER ACADEMIC SOC JAPAN, 5-16-9 HONKOMAGOME, BUNKYO-KU, TOKYO, 113, JAPAN SN 1341-8998 J9 ICHTHYOL RES JI Ichthyol. Res. PD MAY 25 PY 1999 VL 46 IS 2 BP 179 EP 183 DI 10.1007/BF02675436 PG 5 WC Zoology SC Zoology GA 223TH UT WOS:000081856600009 ER PT J AU Di Matteo, T Fabian, AC Rees, MJ Carilli, CL Ivison, RJ AF Di Matteo, T Fabian, AC Rees, MJ Carilli, CL Ivison, RJ TI Strong observational constraints on advection-dominated accretion in the cores of elliptical galaxies SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; galaxies : active; galaxies : individual : NGC 4472; galaxies : individual : NGC 4636; galaxies : individual : NGC 4649 ID MASSIVE BLACK-HOLE; RADIO-CONTINUUM SOURCES; ACTIVE GALACTIC NUCLEI; BRIGHT E/S0 GALAXIES; ION-SUPPORTED TORI; X-RAY; SYNCHROTRON EMISSION; CENTRAL REGIONS; THIN CLOUDS; IONIZED-GAS AB The growing evidence for supermassive black holes in the centres of relatively nearby galaxies has brought into sharper focus the question of why elliptical galaxies, rich in hot gas, do not possess quasar-like luminosities. Recent studies suggest that the presence of advection-dominated accretion flows (ADAFs), with their associated low radiative efficiency, might provide a very promising explanation for the observed quiescence of these systems. Although ADAF models have been applied to a number of low-luminosity systems, compelling observational evidence for their existence is still required. Here, we examine new high-frequency radio observations of the three giant, low-luminosity elliptical galaxies NGC 4649, NGC 4472 and NGC 4636 obtained using the Very Large Array (VLA) and the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT), At these frequencies the predictions are very precise and an ADAF is unequivocally characterized by a slowly rising spectrum with a sharp spectral cut-off produced by thermal synchrotron radiation. Although X-ray analysis of these galaxy cores provides very strong clues for their extreme quiescence (and makes the case of advective accretion plausible), the new radio limits disagree severely with the canonical ADAF predictions which significantly overestimate the observed flux. While the present observations do not rule out the presence of an ADAF in the systems considered here, they do place strong constraints on the model. If the accretion in these objects occurs in an advection-dominated mode, then our radio limits imply that the emission from their central regions must be suppressed. We examine the possibility that the magnetic field in the Row is extremely low, or that synchrotron emission is free-free absorbed by cold material in the accretion Bow. We also discuss whether slow non-radiating accretion flows may drive winds/outflows to remove energy, angular momentum and mass so that the central densities, pressures and emissivities are much smaller than in a standard ADAF. C1 Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Edinburgh, Dept Phys & Astron, Inst Astron, Edinburgh EH9 3HJ, Midlothian, Scotland. RP Di Matteo, T (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Di Matteo, Tiziana/O-4762-2014; Ivison, R./G-4450-2011 OI Di Matteo, Tiziana/0000-0002-6462-5734; Ivison, R./0000-0001-5118-1313 NR 58 TC 72 Z9 72 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 21 PY 1999 VL 305 IS 3 BP 492 EP 504 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 202QE UT WOS:000080663000007 ER PT J AU Rines, K Forman, W Pen, U Jones, C Burg, R AF Rines, K Forman, W Pen, U Jones, C Burg, R TI Constraining q(0) with cluster gas mass fractions: A feasibility study SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : clusters : general; intergalactic medium; X-rays : galaxies ID X-RAY-CLUSTERS; COSMOLOGICAL PARAMETERS; GALAXY CLUSTERS; BARYON FRACTION; DARK-MATTER; DISTANT; EINSTEIN; REDSHIFT; MODELS AB As the largest gravitationally bound objects in the universe, clusters of galaxies may contain a fair sample of the baryonic mass fraction of the universe. Since the gas mass fraction from the hot intracluster medium is believed to be constant in time, the value of the cosmological deceleration parameter q(0) can be determined, in principle, by comparing the calculated gas mass fraction in nearby and distant clusters. To test the potential of this method, we compare the gas fractions derived for a sample of luminous (L-X > 10(45) ergs s(-1)) nearby clusters with those calculated for eight luminous distant (0.3 < z < 0.6) clusters using ASCA and ROSAT observations. For consistency, we evaluate the gas mass fraction at a fixed physical radius of 1 h(50)(-1) Mpc (assuming q(0) = 0.0). We find a best-fit value of q(0) = 0.07 with - 0.47 < q(0) < 0.67 at 95% confidence. This analysis includes both measurement errors and an intrinsic 25% scatter in the gas fractions due to the effects of cooling flows and mergers. We also determine the gas fraction using the method of Evrard, Metzler, and Navarro to find the total mass within r(500), the radius where the mean overdensity of matter is 500 times the critical density. Tn simulations, this method reduces the scatter in the determination of gravitational mass without biasing the mean. We find that it also reduces the scatter in actual observations for nearby clusters but not as much as simulations suggest. Using this method, the best-fit value is q(0) = 0.04 with - 0.50 < q(0) < 0.64. The excellent agreement between these two methods suggests that this may be a useful technique for determining q(0). The constraints on q(0) should improve as more distant clusters are studied and precise temperature profiles are measured to large radii. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Johns Hopkins Univ, Dept Phys & Astron, Bloomberg Ctr, Baltimore, MD 21218 USA. RP Rines, K (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 45 TC 22 Z9 22 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 1999 VL 517 IS 1 BP 70 EP 77 DI 10.1086/307166 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 206RZ UT WOS:000080894200007 ER PT J AU Nicastro, F Fiore, F Matt, G AF Nicastro, F Fiore, F Matt, G TI Resonant absorption in the active galactic nucleus spectra emerging from photoionized gas: Differences between steep and flat ionizing continua SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : Seyfert; line : formation; radiative transfer; X-rays : galaxies ID X-RAY; SEYFERT-GALAXY; ULTRAVIOLET; ABSORBER; QUASARS AB We present photoionization models accounting for both photoelectric and resonant absorption. Resonance absorption lines from C, O, Ne, Mg, Si, S, and Fe between 0.1 and 10 keV are treated. In particular we consider the complex of almost 60 strong Fe L absorption lines around 1 keV. We calculate profiles, intensities, and equivalent widths of each line, considering both Doppler and natural broadening mechanisms. Doppler broadening includes a term accounting for turbulence of the gas along the line of sight. We computed spectra transmitted by gas illuminated by drastically different ionizing continua and compared them to spectra observed in flat X-ray spectrum, broad optical emission-line type active galactic nuclei (AGNs), and steep X-ray spectrum, narrow optical emission-line type AGNs. We show that the similar to 1 keV absorption feature observed in moderate-resolution X-ray spectra of several narrow-line Seyfert 1 galaxies can be explained by photoionization models, taking into account resonance absorption, without requiring relativistic outflowing velocities of the gas, if the physical properties of these absorbers are close to those found in Bat X-ray spectrum Seyfert 1 galaxies. We finally present simulations of the spectra emerging from gas illuminated by both steep and flat ionizing continua, as seen by the AXAF high-energy transmission gratings and the baseline Constellation-X calorimeter. We discuss briefly the relevant physics that can be investigated with these instruments. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron Roma, I-00040 Monte Porzio Catone, RM, Italy. CNR, Ist Astrofis Spaziale, I-00133 Rome, Italy. BeppoSAX Sci Data Ctr, I-00100 Rome, Italy. Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. RP Nicastro, F (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Nicastro, Fabrizio/0000-0002-6896-1364; Fiore, Fabrizio/0000-0002-4031-4157 NR 42 TC 80 Z9 80 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 1999 VL 517 IS 1 BP 108 EP 122 DI 10.1086/307187 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 206RZ UT WOS:000080894200011 ER PT J AU Arce, HG Goodman, AA AF Arce, HG Goodman, AA TI An extinction study of the Taurus dark cloud complex SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; infrared : ISM : continuum; ISM : individual (Taurus dark cloud); techniques : photometric; techniques : spectroscopic ID CIRCUMSTELLAR DISKS; MOLECULAR GAS; STARS; DUST; MAGNITUDE AB We present a study of the detailed distribution of extinction in a region of the Taurus dark cloud complex. Our study uses new BVR images of the region, spectral classification data for 95 stars, and IRAS Sky Survey Atlas (ISSA) 60 and 100 mu m images. We study the extinction of the region in four different ways, and we present the first intercomparison of all these methods, which are as follows: (1) using the color excess of background stars for which spectral types are known, (2) using the ISSA 60 and 100 mu m images, (3) using star counts, and (4) using an optical (V and R) version of the average color excess method used by Lada et al. We find that all four methods give generally similar results-with important exceptions. As expected, all the methods show an increase in extinction due to dense dusty regions (i.e., dark clouds and IRAS cores) and a general increase in extinction with increasing declination, due to a larger content of dust in the northern regions of the Taurus dark cloud complex. Some of the discrepancies between the methods are caused by assuming a constant dust temperature for each line of sight in the ISSA extinction maps and not correcting for unexpected changes in the background stellar population (i.e., the presence of a cluster or Galactic gradients in the stellar density and average V-R color). To study the structure in the dust distribution, we compare the ISSA extinction and the extinction measured for individual stars. From the comparison, we conclude that in the relatively low-extinction regions studied, with 0.9 < A(V) < 3.0 mag (away from filamentary dark clouds and IRAS cores), there are no fluctuations in the dust column density greater than 45% (at the 99.7% confidence level), on scales smaller than 0.2 pc. We also report the discovery of a previously unknown open cluster of stars behind the Taurus dark cloud near R.A. 4(h)19(m), decl. 27 degrees 30' (B1950). C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Arce, HG (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Goodman, Alyssa/A-6007-2010 OI Goodman, Alyssa/0000-0003-1312-0477 NR 26 TC 36 Z9 36 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 1999 VL 517 IS 1 BP 264 EP 281 DI 10.1086/307168 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 206RZ UT WOS:000080894200023 ER PT J AU Huang, MH Bania, TM Bolatto, A Chamberlin, RA Ingalls, JG Jackson, JM Lane, AP Stark, AA Wilson, RW Wright, GA AF Huang, MH Bania, TM Bolatto, A Chamberlin, RA Ingalls, JG Jackson, JM Lane, AP Stark, AA Wilson, RW Wright, GA TI Atomic carbon observations of southern hemisphere HII regions SO ASTROPHYSICAL JOURNAL LA English DT Article DE HII regions; ISM : atoms; ISM : molecules ID H-II REGIONS; CO; CLOUDS AB We report observations of atomic carbon (C I [P-3(1) --> P-3(0)]) for a sample of 49 southern hemisphere H II regions using the Antarctic Submillimeter Telescope and Remote Observatory. The sources are compact and isolated members of the Wilson et al. H109 alpha radio recombination line (RRL) catalog. The fourth Galactic quadrant is well covered by the sample. Atomic carbon emission is detected toward all of the regions, with multiple C I emission components found toward most sources. The RRL velocity is used to identify the C I emission associated with the H II region. We measure the mean velocity difference between the C I and RRL emission to be 0.8 +/- 2.8 km s(-1) Within the measurement errors this is exact agreement in velocity; we conclude that all H II regions have associated C I emission. The mean C I line temperature of these components is 2.4 +/- 1.8 K, compared with 0.7 +/- 0.7 K for the C I emission components not associated with the H II region. This suggests that C I intensity is dominated by local heating. The FWHM line width of C I gas associated with H II regions also is marginally greater than that found for unassociated gas (6.7 +/- 3.0, compared with 4.8 +/- 2.4 km s(-1)). C1 Boston Univ, Dept Astron, Boston, MA 02215 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. AT&T Bell Labs, Crawford Hill Lab, Holmdel, NJ 07733 USA. RP Huang, MH (reprint author), Boston Univ, Dept Astron, 725 Commonwealth Ave, Boston, MA 02215 USA. RI Bania, Thomas/H-2318-2014; OI Wilson, Robert/0000-0001-5694-6725 NR 14 TC 14 Z9 14 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 1999 VL 517 IS 1 BP 282 EP 291 DI 10.1086/307194 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 206RZ UT WOS:000080894200024 ER PT J AU Napiwotzki, R Green, PJ Saffer, RA AF Napiwotzki, R Green, PJ Saffer, RA TI A comparative study of the mass distribution of extreme-ultraviolet-selected white dwarfs SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; stars : atmospheres; stars : evolution; ultraviolet : stars; white dwarfs ID BINARY RE J1629+780; ATMOSPHERIC PARAMETERS; TEMPERATURE SCALE; SPACE DENSITY; STARS; EVOLUTION; COMPANION; HYDROGEN; EXPLORER; SPECTROSCOPY AB We present new determinations of effective temperature, surface gravity, and masses for a sample of 46 hot DA white dwarfs selected from the Extreme Ultraviolet Explorer (EUVE) and ROSAT Wide Field Camera bright source lists in the course of a near-infrared survey for low-mass companions. Our analysis, based on hydrogen non-LTE model atmospheres, provides a map of LTE correction vectors, which allow a thorough comparison with previous LTE studies. We find that previous studies underestimate both the systematic errors and the observational scatter in the determination of white dwarf parameters obtained via fits to model atmospheres. The structure of very hot or low-mass white dwarfs depends sensitively on their history. To compute white dwarf masses, we thus use theoretical mass-radius relations that take into account the complete evolution from the main sequence. We find a peak mass of our white dwarf sample of 0.59 M., in agreement with the results of previous analyses. However, we do not confirm a trend of peak mass with temperature reported in two previous analyses. Analogous to other EUV-selected samples, we note a lack of low-mass white dwarfs and a large fraction of massive white dwarfs. Only one white dwarf is likely to have a helium core. While the lack of helium white dwarfs in our sample can be easily understood from their high cooling rate, and therefore low detection probability in our temperature range, this is not enough to explain the large fraction of massive white dwarfs. This feature very likely results from a decreased relative sample volume for low-mass white dwarfs caused by interstellar absorption in EUV-selected samples. C1 Dr Remeis Sternwarte, D-96049 Bamberg, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Villanova Univ, Dept Astron & Astrophys, Villanova, PA 19085 USA. RP Napiwotzki, R (reprint author), Dr Remeis Sternwarte, Sternwartstr 7, D-96049 Bamberg, Germany. EM ai23@sternwarte.uni-erlangen.de; pgreen@da.harvard.edu; saffer@ast.vill.edu NR 52 TC 124 Z9 124 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 1999 VL 517 IS 1 BP 399 EP 415 DI 10.1086/307170 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 206RZ UT WOS:000080894200034 ER PT J AU Geller, MJ Diaferio, A Kurtz, MJ AF Geller, MJ Diaferio, A Kurtz, MJ TI The mass profile of the Coma galaxy cluster SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; galaxies : clusters : individual (Coma); methods : statistical; surveys ID CFA SURVEY SLICE; FAINTER GALAXIES; RICH CLUSTERS; X-RAY; DARK MATTER; REDSHIFTS; MORPHOLOGY; DYNAMICS; REGIONS AB We use a new redshift survey complete to m(R) similar or equal to 15.4 within 4.degrees 25 from the center of the Coma cluster to measure the mass profile of the cluster to r similar to 5.5 h(-1) Mpc. We extend the profile to r similar to 10 h(-1) Mpc with a further sample complete to m(R) = 15.4 in 42% of the area within a 10 degrees radius and to m(zw) = 15.5 in the remaining area. Galaxies within this region are falling onto the cluster on moderately radial orbits and thus do not satisfy virial equilibrium. Nonetheless, identification of the caustics in redshift space provides an estimate of the gravitational potential at radius r and hence of the system mass, M(less than or equal to 10 h(-1) Mpc)= (1.65 +/- 0.41) x 10(15) h(-1) M-. (1 sigma error). Previous mass estimates derived from optical and X-ray observations are limited to r less than or equal to 2.5 h(-1) Mpc. Our mass profile is consistent with these estimates but extends to distances 4 times as large. Over the entire range, the mass increases with r at the rate expected for a Navarro, Frenk, & White density profile. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Max Planck Inst Astrophys, D-85740 Garching, Germany. RP Geller, MJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI KURTZ, Michael /B-3890-2009 NR 38 TC 55 Z9 55 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 1999 VL 517 IS 1 BP L23 EP L26 DI 10.1086/312024 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 206TA UT WOS:000080894300006 ER PT J AU Lebach, DE Ratner, MI Shapiro, II Ransom, RR Bietenholz, MF Bartel, N Lestrade, JF AF Lebach, DE Ratner, MI Shapiro, II Ransom, RR Bietenholz, MF Bartel, N Lestrade, JF TI Milliarcsecond change of IM Pegasi radio position in 1 hour coincident with sharp rise in flux density SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrometry; binaries : close; radio continuum : stars; stars : activity; stars : individual (IM Pegasi); techniques : interferometric ID VLBI OBSERVATIONS; BINARY-SYSTEMS; STARS; EMISSION; POLARIZATION; CATALOG; LINK AB Continuum VLBI observations at 3.6 cm of the RS CVn binary star IM Pegasi (HR 8703) for similar to 16 hr beginning on 1997 January 16 revealed an apparent motion of the star's radio position that coincided temporally with a large relative change in its flux density. Specifically, a rise in flux density from 18 to 46 mJy in 1.4 hr coincided with a detected position change over that interval of (Delta alpha, Delta delta) = (-0.68 +/- 0.15, 0.55 +/- 0.20) mas. The magnitude of this position change is much larger than can be explained by parallax, proper motion, and orbital motion and is about two-thirds the estimated angular diameter of the primary component of the binary. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. York Univ, Dept Phys & Astron, N York, ON M3J 1P3, Canada. Observ Paris, F-92195 Meudon, France. RP Lebach, DE (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 29 TC 19 Z9 19 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 1999 VL 517 IS 1 BP L43 EP L46 DI 10.1086/312026 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 206TA UT WOS:000080894300011 ER PT J AU Balakrishnan, N Kharchenko, V Dalgarno, A AF Balakrishnan, N Kharchenko, V Dalgarno, A TI Translational energy relaxation of hot O(D-1) atoms SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID FAST NITROGEN-ATOMS; NIGHTTIME TERRESTRIAL THERMOSPHERE; AB-INITIO MO; VELOCITY RELAXATION; NITRIC-OXIDE; RARE-GASES; COLLISIONS; N-2; THERMALIZATION; KINETICS AB Quantum mechanical calculations of the thermalization of initially energetic O(D-1) atoms in bath gas of N-2 molecules are carried out. The results are in excellent agreement with measurements of the translational energy relaxation of O(D-1) atoms produced in the 157 nm photodissociation of O-2 and the 193 nm photodissociation of N2O in an N-2 atmosphere. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Balakrishnan, N (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. NR 21 TC 22 Z9 22 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAY 20 PY 1999 VL 103 IS 20 BP 3999 EP 4001 DI 10.1021/jp990041l PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 200XK UT WOS:000080565300026 ER PT J AU Freeman, G AF Freeman, G TI Regional specification during embryogenesis in the inarticulate brachiopod Discinisca SO DEVELOPMENTAL BIOLOGY LA English DT Article DE early development; cleavage patterns; axes of symmetry; fate maps; regional specification ID LARVAL DEVELOPMENT AB The process of embryogenesis is described for the inarticulate brachiopod Discinisca strigata of the family Discinidae. A fate map has been constructed for the early embryo. The animal half of the egg forms the dorsal ectoderm of the apical and mantle lobes. The vegetal half forms mesoderm and endoderm and is the site of gastrulation; it also forms the ectoderm of the ventral regions of the apical and mantle lobes of the larva. The plane of the first cleavage goes through the animal-vegetal axis of the egg along the future plane of bilateral symmetry of the larva. The timing of regional specification in these embryos was examined by isolating animal, vegetal, or lateral regions at different times from the 2-cell stage through gastrulation. Animal halves isolated at the 8-cell and blastula stages formed an epithelial vesicle and did not gastrulate. When these halves were isolated from blastulae they formed the cell types typical of apical and mantle lobes. Vegetal halves isolated at all stages gastrulated and formed a more or less normal larva; the only defect these larvae had was the lack of an apical tuft, which normally forms from cells at the animal pole of the embryo. When lateral isolates were created at all developmental! stages, these halves gastrulated. Cuts which separated presumptive anterior and posterior regions generated isolates at the 4-cell and blastula stages that formed essentially normal larvae; however, at the midgastrula stage these halves formed primarily anterior or posterior structures indicating that regional specification had taken place along the anterior-posterior axis. The plane of the first cleavage, which predicts the plane of bilateral symmetry, can be shifted by either changing the cleavage pattern that generates the bilateral 16-cell blastomere configuration or by isolating embryo halves prior to, or during, the 16-cell stage. These results indicate that while the plane of the first cleavage predicts the axis of bilateral symmetry, the axis is not established until the fourth cleavage. The development of Discinisca is compared to development in the inarticulate brachiopod Glottidia of the family Lingulidae and to Phoronis in the phylum Phoronida. (C) 1999 Academic Press. C1 Univ Texas, Ctr Dev Biol, Dept Zool, Austin, TX 78712 USA. Smithsonian Trop Res Inst, Naos Marine Lab, Panama City, Panama. RP Freeman, G (reprint author), Univ Texas, Ctr Dev Biol, Dept Zool, Austin, TX 78712 USA. NR 19 TC 28 Z9 28 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0012-1606 J9 DEV BIOL JI Dev. Biol. PD MAY 15 PY 1999 VL 209 IS 2 BP 321 EP 339 DI 10.1006/dbio.1999.9251 PG 19 WC Developmental Biology SC Developmental Biology GA 198WW UT WOS:000080448100009 PM 10328924 ER PT J AU Hardcastle, MJ Worrall, DM Birkinshaw, M AF Hardcastle, MJ Worrall, DM Birkinshaw, M TI Extended X-ray emission from the BL Lac object PKS 0521-365 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : active; galaxies : individual : PKS 0521-365; X-rays : galaxies ID TELESCOPE IMAGING SURVEY; LACERTAE OBJECTS; RADIO-GALAXIES; ENERGY-DISTRIBUTIONS; HOST GALAXIES; BLAZARS; PKS-0521-365; ENVIRONMENTS; HOTSPOTS; QUASARS AB Models that seek to unify BL Lacs and low-power radio galaxies predict that the two types of object should show similar isotropically emitted X-ray emission. Testing this is usually limited by difficulties in separating strong X-ray emission from a BL Lac nucleus and surrounding low surface-brightness emission. In this paper we report ROSAT HRI observations of the z = 0.055 BL Lac object PKS 0521-365. We are able to separate a luminous extended X-ray component from the bright nucleus. Using a new radio map, we show that it is unlikely that the extended emission is due to inverse Compton scattering of photons from the active nucleus, and instead interpret it as thermal emission from dense, rapidly cooling gas. This is a more extreme environment than is found in typical FR I radio galaxies, and may pose a problem for unified models. C1 Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Hardcastle, MJ (reprint author), Univ Bristol, Dept Phys, Tyndall Ave, Bristol BS8 1TL, Avon, England. RI Hardcastle, Martin/E-2264-2012 OI Hardcastle, Martin/0000-0003-4223-1117 NR 47 TC 9 Z9 9 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 11 PY 1999 VL 305 IS 2 BP 246 EP 252 DI 10.1046/j.1365-8711.1999.02353.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 201BJ UT WOS:000080574500002 ER PT J AU Graham, JA Ferrarese, L Freedman, WL Kennicutt, RC Mould, JR Saha, A Stetson, PB Madore, BF Bresolin, F Ford, HC Gibson, BK Han, MS Hoessel, JG Huchra, J Hughes, SM Illingworth, GD Kelson, DD Macri, L Phelps, R Sakai, S Silbermann, NA Turner, A AF Graham, JA Ferrarese, L Freedman, WL Kennicutt, RC Mould, JR Saha, A Stetson, PB Madore, BF Bresolin, F Ford, HC Gibson, BK Han, MS Hoessel, JG Huchra, J Hughes, SM Illingworth, GD Kelson, DD Macri, L Phelps, R Sakai, S Silbermann, NA Turner, A TI The Hubble Space Telescope key project on the Extragalactic Distance Scale. XX. The discovery of cepheids in the Virgo Cluster galaxy NGC 4548 SO ASTROPHYSICAL JOURNAL LA English DT Article DE Cepheids; distance scale; galaxies : clusters : individual (Virgo); galaxies : individual (NGC 4548) ID PEAK BRIGHTNESS; SPIRAL GALAXIES; CCD PHOTOMETRY; CALIBRATION; PERFORMANCE; VARIABLES; CONSTANT; WFPC2; STARS AB We report on the discovery and properties of Cepheid variable stars in the barred spiral galaxy NGC 4548, which is a member of the Virgo cluster of galaxies. This is one of the galaxies being observed as part of the Hubble: Space Telescope (HST) Key Project on the Extragalactic Distance Scale, which aims to determine the Hubble constant to 10% accuracy. Our analysis is based on observations made with the Wide Field and Planetary Camera 2 during 1996 and 1997. We identify 24 probable Cepheids with periods between 16 and 38 days. They were observed over 13 epochs with the F555W filter and eight epochs with the F814W filter. The HST F555W and F814W data have been transformed to the Johnson V and Cousins I magnitude systems, respectively. Photometry has principally been carried out using the DAOPHOT/ALLFRAME package. A comparison is made with parallel measurements using the DoPHOT package. Apparent period-luminosity relations for V and I have been constructed., Assuming values of mu(0) = 18.50 +/- 0.10 mag and E(B-V) = 0.10 mag for the distance modulus and reddening of the Large Magellanic Cloud, a true distance modulus of 31.01 +/- 0.28 mag is derived corresponding to a distance of 15.9 +/- 2.0 Mpc. HST Cepheid distances of other spiral galaxies in the Virgo Cluster are discussed. Their good agreement with the new NGC 4548 distance strengthens the evidence that this galaxy lies within the Virgo cluster core. C1 Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. CALTECH, Pasadena, CA 91125 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Inst Adv Studies, Weston, ACT 2611, Australia. Kitt Peak Natl Observ, Natl Opt Astron Observ, Tucson, AZ 85726 USA. Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada. CALTECH, NASA, IPAC, Pasadena, CA 91125 USA. European So Observ, D-8046 Garching, Germany. Johns Hopkins Univ, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Colorado, CASA, Boulder, CO 80309 USA. Univ Wisconsin, Madison, WI 53706 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Royal Greenwich Observ, Cambridge CB3 0HA, England. Univ Calif Santa Cruz, Lick Observ, Santa Cruz, CA 95064 USA. RP Graham, JA (reprint author), Carnegie Inst Washington, Dept Terr Magnetism, 5241 Broad Branch Rd NW, Washington, DC 20015 USA. RI Gibson, Brad/M-3592-2015 OI Gibson, Brad/0000-0003-4446-3130 NR 55 TC 45 Z9 45 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 1999 VL 516 IS 2 BP 626 EP 646 DI 10.1086/307151 PN 1 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 205FQ UT WOS:000080811000012 ER PT J AU Ho, LC AF Ho, LC TI The spectral energy distributions of low-luminosity active galactic nuclei SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : nuclei; galaxies : Seyfert ID HUBBLE-SPACE-TELESCOPE; DWARF SEYFERT NUCLEI; STARBURST GALAXIES; VLBI OBSERVATIONS; SPIRAL GALAXIES; ULTRAVIOLET CONTINUUM; ASCA OBSERVATIONS; BRIGHT GALAXIES; EXTINCTION LAW; RADIO GALAXIES AB As a step toward elucidating the physical conditions in nearby active galaxies, this paper presents spectral energy distributions (SEDs) of a sample of seven low-luminosity active galactic nuclei (AGNs). SEDs for four objects are presented for the first time (NGC 4261, NGC 4579, NGC 6251, and M84); the data for the remaining three (M81, M87, and NGC 4594) have been substantially updated compared to previous studies. The nuclear fluxes were carefully selected so as to avoid contamination by emission from the host galaxy, which can be substantial for very weak nuclei. The present sample of low-luminosity nuclei exhibits SEDs that look markedly different from the canonical broadband continuum spectrum of luminous AGNs. The most striking difference is that the low-luminosity objects lack an ultraviolet excess (the "big blue bump"), a feature normally associated with emission from a standard optically thick, geometrically thin accretion disk. The weakness of the ultraviolet band leads to an unusually steep optical-ultraviolet continuum shape and a more pronounced contribution from the X-rays to the ionizing spectrum. It is argued that the absence of the big blue bump is a property intrinsic to the SEDs and not an artifact of strong dust extinction. Another notable property of the SEDs is the prominence of the compact, flat-spectrum radio component relative to the emission in other energy bands. All seven nuclei in the sample, including three hosted by spiral galaxies, technically qualify as "radio-loud" objects according to conventional criteria. Finally, the integrated spectra confirm the exceptional weakness of the nuclei: the bolometric luminosities range from 2 x 10(41) to 8 x 10(42) ergs s(-1), or similar to 10(-6)-10(-3) times the Eddington rate for the black hole masses previously reported for these galaxies. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Observ Carnegie Inst Washington, 813 Santa Barbara St, Pasadena, CA 91101 USA. NR 89 TC 285 Z9 288 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 1999 VL 516 IS 2 BP 672 EP 682 DI 10.1086/307137 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 205FQ UT WOS:000080811000015 ER PT J AU Satyapal, S Watson, DM Forrest, WJ Pipher, JL Fischer, J Greenhouse, MA Smith, HA Woodward, CE AF Satyapal, S Watson, DM Forrest, WJ Pipher, JL Fischer, J Greenhouse, MA Smith, HA Woodward, CE TI Probing the dust-enshrouded regions of the interacting galaxy system ARP 299: A near-infrared study SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (Arp 299); galaxies : nuclei; infrared : galaxies; infrared : ISM : lines and bands ID MICRON EMISSION FEATURE; STARBURST GALAXIES; SUPERNOVA-REMNANTS; STAR-FORMATION; LUMINOSITY FUNCTION; RECOMBINATION-LINE; SPIRAL GALAXIES; STANDARD STARS; RADIO-SOURCES; GAMMA-RATIO AB We present high spectral resolution (lambda/delta lambda congruent to 10(3)) Pa beta(1.28 mu m) and Br gamma(2.17 mu m), 3.29 mu m dust feature, and near-infrared broadband images of the Arp 299 = NGC 3690/IC 694 galaxy system. The emission is found to be concentrated at the positions of three active regions, known as sources A, B, and C. From our Br gamma/Pa beta flux ratio we find the visual extinction toward the ionized gas in A, B, and C is similar to 6, 6, and 2 magnitudes, respectively, assuming case B recombination and a foreground screen geometry for the obscuring material. Our observations can be explained entirely by a starburst model for the Arp 299 system. The putative active galactic nucleus (AGN) in source A does not dominate the properties of this source. We see no evidence of broad recombination lines. In addition, the ratio of the 3.29 mu m dust feature to total luminosity, a tracer of starburst activity, is consistent in each source with that seen in M82 and other starburst galaxies. Also, our imaging observations reveal that the dust feature emission is concentrated in the nucleus of source A, contrary to the extended annular distribution of the feature emission seen surrounding the nucleus of the more distant Seyfert galaxy NGC 7469. In this galaxy, the absence of the feature emission in the nucleus has been attributed to the destruction of the dust carriers in the hard radiation held surrounding the AGN. Our observations suggest that all of the active regions in Arp 299 are characterized by starburst episodes. The observed CO indices and Br gamma equivalent widths imply that source B is older than source A and source C is the youngest star-forming region. Although these regions are probably complex physical systems not necessarily characterized by a single coeval population of stars, we have compared our observations with an instantaneous starburst model with a Salpeter initial mass function. Using this simple model, we find starburst ages of similar to 6 x 10(6), 8 x 10(6), and 4 x 10(6) for sources A, B, and C, respectively. C1 Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82701 USA. RP NASA, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 USA. EM satyapal@stars.gsfc.nasa.gov NR 54 TC 14 Z9 14 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 1999 VL 516 IS 2 BP 704 EP 715 DI 10.1086/307130 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 205FQ UT WOS:000080811000018 ER PT J AU Harrus, IM Slane, PO AF Harrus, IM Slane, PO TI An ASCA study of the supernova remnant G39.2-0.3 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (G39.2-0.3); radiation mechanisms : nonthermal; supernova remnants; X-rays : ISM ID X-RAY; EMISSION; PULSAR AB We present the analysis of archival data from the Advanced Satellite for Cosmology and Astrophysics of the supernova remnant (SNR) G39.2-0.3. G39.2-0.3 has been sometimes characterized as a shell-like remnant in the literature, but our high-energy imaging and spectral analysis show the unambiguous composite nature of the remnant. We find that part of the contribution to the X-ray emission of G39.2-0.3 is distinctly nonthermal, best described by a power law with a photon index (2.53(-0.27)(+0.34)). The region of emission is consistent with a point source (extension consistent with the point-spread function of the detector at the off-axis angle of the observation) and is roughly defined by a circle of radius similar to 4'. A second contribution comes from a thermal component, which contributes flux primarily at low energies. Despite the absence of any pulsed emission detected from the compact source, we argue that the emission is most probably due to a rotating compact object that is powering the detected synchrotron nebula within the SNR. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Harrus, IM (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 22 TC 16 Z9 16 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 1999 VL 516 IS 2 BP 811 EP 816 DI 10.1086/307138 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 205FQ UT WOS:000080811000027 ER PT J AU Kraemer, KE Deutsch, LK Jackson, JM Hora, JL Fazio, GG Hoffmann, WF Dayal, A AF Kraemer, KE Deutsch, LK Jackson, JM Hora, JL Fazio, GG Hoffmann, WF Dayal, A TI The mid-infrared properties of three star-forming sites in NGC 6334 SO ASTROPHYSICAL JOURNAL LA English DT Article DE HII regions; infrared : ISM : continuum; ISM : individual (NGC 6334); radio continuum : ISM; stars : formation ID H-II REGIONS; PHOTODISSOCIATION REGIONS; NGC-6334 COMPLEX; METHANOL MASERS; MOLECULAR CLOUD; ARRAY CAMERA; WATER-VAPOR; EMISSION; NEBULA; SCATTERING AB To investigate their dust properties, we have imaged three sites of massive star formation in the giant H II region/star-forming cloud NGC 6334 with the MIRAC2 instrument. We obtained high-resolution (1 ") continuum images at 12.5 and 20.6 mu m toward each region, which were compared with observations of the radio and near-infrared (near-IR) continuum emission. Both compact sources and extended emission were found at all three star-forming sites. The detected sources span a wide range of evolutionary states in this highly complex star-forming cloud. The infrared sources near NGC 6334 I were resolved into at least four subsources. One such source is substantially colder, denser, and more optically thick than the other mid-IR sources in the region and may be at the earliest stages of stellar formation. Another may be a torus or disk of dust and gas surrounding an embedded B star. NGC 6334 I was also imaged at additional wavelengths (8.8, 9.8, and 11.7 mu m) to search for silicate absorption. Only at the H II region is there a deep silicate absorption feature from foreground dust. Toward the NGC 6334 IV, warm dust is associated with both the inner portions of the massive molecular torus or disk and with the bipolar continuum lobes. A compact mid-IR source, associated with the near-IR and radio source [HHS87] IRS 20, is cooler and more optically thick than the dust emission associated with the H II region. Toward NGC 6334 V, four embedded sources were found, including one previously unidentified object. This newly identified compact object, associated with a dust temperature peak and a radio source, is probably in a more advanced stage of star formation than the other compact mid-IR sources in NCC 6334. C1 Boston Univ, Dept Astron, Boston, MA 02215 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, IPAC, Pasadena, CA 91125 USA. RP Kraemer, KE (reprint author), Boston Univ, Dept Astron, 725 Commonwealth Ave, Boston, MA 02215 USA. OI Hora, Joseph/0000-0002-5599-4650; Kraemer, Kathleen/0000-0002-2626-7155 NR 63 TC 30 Z9 30 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 1999 VL 516 IS 2 BP 817 EP 833 DI 10.1086/307149 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 205FQ UT WOS:000080811000028 ER PT J AU Apponi, AJ McCarthy, MC Gottlieb, CA Thaddeus, P AF Apponi, AJ McCarthy, MC Gottlieb, CA Thaddeus, P TI Astronomical detection of rhomboidal SiC3 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : molecules; line : identification; molecular data; molecular processes; radio lines : ISM ID IRC +10216; IRC+10216; ENVELOPE AB Seven rotational transitions of SIG,, a planar, highly polar ring molecule, have been detected in the millimeterwave band in the expanding envelope of the evolved carbon star IRC + 10216. On the assumption that SiC3 has: the same 40 " diameter shell as SiCC, the mean column density of SiC3 is 4.3 x 10(12) cm(-2). The rotational excitation of SiC3 is similar to that of SiCC, with a low rotational temperature within the K-stacks of 10-20 K and a high rotational temperature across the K-stacks of roughly 50 K, which is probably close to the kinetic temperature of the shell. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Apponi, AJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 14 TC 96 Z9 97 U1 1 U2 7 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 1999 VL 516 IS 2 BP L103 EP L106 DI 10.1086/311998 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 205FV UT WOS:000080811400014 ER PT J AU Krebs, E AF Krebs, E TI Patagonia - Natural history, prehistory and ethnography at the uttermost end of the earth SO TLS-THE TIMES LITERARY SUPPLEMENT LA English DT Book Review C1 Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. RP Krebs, E (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU TIMES SUPPLEMENTS LIMITED PI MARKET HARBOROUGH PA TOWER HOUSE, SOVEREIGN PARK, MARKET HARBOROUGH LE87 4JJ, ENGLAND SN 0307-661X J9 TLS-TIMES LIT SUPPL JI TLS-Times Lit. Suppl. PD MAY 7 PY 1999 IS 5014 BP 7 EP 7 PG 1 WC Humanities, Multidisciplinary SC Arts & Humanities - Other Topics GA 196CG UT WOS:000080291000005 ER PT J AU Derevianko, A Johnson, WR Safronova, MS Babb, JF AF Derevianko, A Johnson, WR Safronova, MS Babb, JF TI High-precision calculations of dispersion coefficients, static dipole polarizabilities, and atom-wall interaction constants for alkali-metal atoms SO PHYSICAL REVIEW LETTERS LA English DT Article ID VAN-DER-WAALS; FRANCIUM AB The van der Waals coefficients for the alkali-metal atoms from Na to Fr interacting in their ground states are calculated using relativistic ab initio methods. The accuracy of the calculations is estimated by also evaluating atomic static electric-dipole polarizabilities and coefficients for the interaction of the atoms with a perfectly conducting wall. The results are in excellent agreement with the latest data from studies of magnetic field induced Feshbach resonances in ultracold collisions of Na and of Rb atoms. For Cs we provide critically needed data for ultracold collision studies. [S0031-9007(99)09020-1]. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. RI Derevianko, Andrei/G-8356-2011; OI Babb, James/0000-0002-3883-9501 NR 25 TC 245 Z9 247 U1 1 U2 25 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 3 PY 1999 VL 82 IS 18 BP 3589 EP 3592 DI 10.1103/PhysRevLett.82.3589 PG 4 WC Physics, Multidisciplinary SC Physics GA 191UW UT WOS:000080040800007 ER PT J AU Regan, MH Case, DT Brundige, JC AF Regan, MH Case, DT Brundige, JC TI Articular surface defects in the third metatarsal and third cuneiform: Nonosseous tarsal coalition SO AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY LA English DT Article DE foot; developmental defect; tarsometatarsal joint ID LISFRANC JOINT COMPLEX; INJURIES; RARE AB Frequencies of articular surface defects on the third metatarsal and third cuneiform, seen as pits of varying sizes on the plantar one third of the tarsometatarsal articular face, were investigated in skeletal populations from North America and Japan, as well as in gibbon, orangutan, chimpanzee, and gorilla skeletons. The apes did not exhibit the defects, although the number of observed specimens of each type was small. The newly presented human frequencies corresponded well with those from other published sources. The defects appeared both unilaterally and bilaterally, with no apparent sex or side biases. Statistical tests between the various populations found that, in general, geographically close. populations had more similar frequencies of the defect. Possible etiologies for the defect were investigated, including biomechanical influences, degenerative arthritis, infection, trauma, and a developmental condition known as tarsal coalition, which proved to be the best explanation. Tarsal coalition results from the failure of a joint space to form properly during fetal growth. It can occur between any two adjacent bones of the foot. Several clinically important coalitions, whose presence interferes with normal walking, are known. However, coalition between the third metatarsal and third cuneiform has not been reported in the clinical Literature, suggesting that the defect causes little or no foot dysfunction. Tarsal coalition is thought to have a strong genetic component, suggesting that the pit defect may be useful as a skeletal nonmetric trait, as others have stated. (C) 1999 Wiley-Liss, Inc. C1 Smithsonian Inst, Natl Inst Nat Hist, Washington, DC 20560 USA. RP Regan, MH (reprint author), Arizona State Univ, Dept Anthropol, Box 872402, Tempe, AZ 85287 USA. NR 51 TC 14 Z9 14 U1 1 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0002-9483 J9 AM J PHYS ANTHROPOL JI Am. J. Phys. Anthropol. PD MAY PY 1999 VL 109 IS 1 BP 53 EP 65 DI 10.1002/(SICI)1096-8644(199905)109:1<53::AID-AJPA6>3.0.CO;2-P PG 13 WC Anthropology; Evolutionary Biology SC Anthropology; Evolutionary Biology GA 193MR UT WOS:000080140700006 PM 10342465 ER PT J AU Benezra, N AF Benezra, N TI Mind over matter - Bruce Nauman SO ARTNEWS LA English DT Article C1 Smithsonian Inst, Hirshhorn Museum & Sculpture Garden, Washington, DC 20560 USA. RP Benezra, N (reprint author), Smithsonian Inst, Hirshhorn Museum & Sculpture Garden, Washington, DC 20560 USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU ARTNEWS ASSOCIATES PI NEW YORK PA 48 WEST 38TH STREET, NEW YORK, NY 10018 USA SN 0004-3273 J9 ART NEWS JI Artnews PD MAY PY 1999 VL 98 IS 5 BP 143 EP 143 PG 1 WC Art SC Art GA 190GZ UT WOS:000079955600033 ER PT J AU Tonry, JL Kochanek, CS AF Tonry, JL Kochanek, CS TI Redshifts of the gravitational lenses MG 0414+0534 and MG 0751+2716 SO ASTRONOMICAL JOURNAL LA English DT Article DE distance scale; gravitational lensing; quasars : individual (MG 0414+0534, MG 0751+2716) ID COSMOLOGICAL CONSTANT; SYSTEM MG-0414+0534; GALAXIES; PG-1115+080; B1422+231; LINES; DUST AB We report redshifts in two gravitational lens systems, MG 0414 + 0534 and MG 0751 + 2716. The lens galaxy in MG 0414 + 0534 lies at z(l) = 0.9584 +/- 0.0002. The luminosity and extreme red color of the lens are thus typical of a passively evolving early-type similar to 2L(*) galaxy. The galaxy cannot have a significant global mean extinction without being anomalously luminous. The lens galaxy in MG 0751 + 2716 has a redshift of z(l) = 0.3502 +/- 0.0003, and it is a member of a small group. The group includes the nearby bright companion galaxy whose redshift we confirmed to be z = 0.3501 +/- 0.0001 and a nearby emission-line galaxy with z = 0.3505 +/- 0.0003. A second emission-line galaxy with z = 0.5616 +/- 0.0001 was found nearly superposed on the first emission-line galaxy. The source in MG 0751 + 2716 is a z(s) = 3.200 +/- 0.001 radio quasar. For hat universes with Ohm(0) = 1.0 (0.3), 96% (87%) of lenses like MG 0414 + 0534 and 7% (3%) of lenses like MG 0751 + 2716 are expected to have lower lens redshifts than observed. C1 Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Tonry, JL (reprint author), Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. NR 25 TC 63 Z9 64 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAY PY 1999 VL 117 IS 5 BP 2034 EP 2038 DI 10.1086/300834 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 201XB UT WOS:000080621200007 ER PT J AU Schlegel, EM AF Schlegel, EM TI ROSAT high resolution imager observations of three magnetic cataclysmic variables: EP Draconis, EUVE J2115-58, and AR URSAE majoris SO ASTRONOMICAL JOURNAL LA English DT Article DE stars : variables : other; X-rays ID AM-HERCULIS; ABSORPTION DIPS; ECLIPSING AM; STARS; PERIOD; POLAR; CAMELOPARDALIS; =H1907+690; DISCOVERY; STATES AB I present ROSAT HRI observations of the magnetic cataclysmic variables EP Dra, EUVE J72115 - 58, and AR UMa. The HRI light curve for EP Dra shows the typical polar behavior for one-pole accretion. When the data from a 1993 PSPC observation are phased correctly, the PSPC and HRI light curves appear nearly identical in behavior. The eclipses differ in width, however. The PSPC eclipse is about half the width of the HRI eclipse, suggesting that the HRI eclipse is a combined eclipse and stream occultation. The EUVE J2115-58 observation was obtained in two parts approximately 180 days apart. The count rates differ by a factor of 3 between the two epochs. The X-ray data do not resolve the period ambiguity, because the light curves look very similar when folded on every published period. A period search using the longer observation yields two periods of 102.6 and 110.4 minutes. The HRI observation for AR UMa occurred during an off state. AR UMa is detected at a significance level of 3 sigma at a luminosity of similar to 4 x 10(29) ergs s(-1), which likely arises from the M dwarf companion. C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Schlegel, EM (reprint author), Smithsonian Astrophys Observ, 60 Garden St, Cambridge, MA 02138 USA. NR 35 TC 3 Z9 3 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAY PY 1999 VL 117 IS 5 BP 2494 EP 2502 DI 10.1086/300863 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 201XB UT WOS:000080621200036 ER PT J AU Perrin, G du Foresto, VC Ridgway, ST Mennesson, B Ruilier, C Mariotti, JM Traub, WA Lacasse, MG AF Perrin, G du Foresto, VC Ridgway, ST Mennesson, B Ruilier, C Mariotti, JM Traub, WA Lacasse, MG TI Interferometric observations of R Leonis in the K band - First direct detection of the photospheric pulsation and study of the atmospheric intensity distribution SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE techniques : interferometric; stars : fundamental parameters; stars : individual : R Leo; stars : AGE and post-AGB; infrared : stars ID MIRA VARIABLES; IOTA INTERFEROMETER; ANGULAR DIAMETER; O-CETI; GIANTS; SUPERGIANTS; EXTENSION; EMISSION; SPECTRA; RADII AB The Mira-type star R Leonis was observed at two different epochs in the K band with the FLUOR beam combiner on the IOTA interferometer. A variation of diameter is clearly detected for the very first time at this wavelength revealing an apparent pulsation of atmospheric layers very close to the stellar photosphere. We discuss the excess of visibility measured at high spatial frequencies and show that they very likely reveal smaller diameters of the photosphere (22-24 mas) than those deduced on the basis of shorter frequency components. This smaller diameter makes R Leonis a fundamental pulsator. Mira models are compared to our data and a disagreement with spatial intensity distribution and dynamical behaviour is found. C1 Observ Paris, DESPA, F-92195 Meudon, France. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Perrin, G (reprint author), Observ Paris, DESPA, F-92195 Meudon, France. EM perrin@hplyot.obspm.fr NR 43 TC 83 Z9 83 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAY PY 1999 VL 345 IS 1 BP 221 EP 232 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 195UL UT WOS:000080270500031 ER PT J AU Kaaret, P AF Kaaret, P TI Pulsar radiation and quantum gravity SO ASTRONOMY & ASTROPHYSICS LA English DT Letter DE gravitation; stars : pulsars : general; stars : pulsars : individual : Crab; gamma rays : observations ID RAY; TESTS AB Quantum gravity may lead to an energy dependence in the speed of light. The high energy radiation from gamma-ray pulsars can be used to place limits on such effects. We find that emission from the Crab pulsar at energies above 2 GeV trails that at 70-100 MeV by no more than 0.35 ms (95% confidence) and place a lower bound on the energy scale of quantum gravitational effects on the speed of light of 1.8 x 10(15) GeV. This bound might be improved by two orders of magnitude by observation of pulsations from the Crab at higher energies, 50-100 GeV, in the near future. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kaaret, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM pkaaret@cfa.harvard.edu NR 16 TC 40 Z9 40 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAY PY 1999 VL 345 IS 2 BP L32 EP L34 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 196GH UT WOS:000080300300003 ER PT J AU Kim, DW Elvis, M AF Kim, DW Elvis, M TI Radio-quiet red quasars SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; quasars : general; X-rays : galaxies ID X-RAY-PROPERTIES; ROSAT SERENDIPITY SURVEY; ACTIVE GALACTIC NUCLEI; ENERGY-DISTRIBUTIONS; COMPLETE SAMPLE; TYPE-2 QSO; SKY SURVEY; GALAXIES; SPECTRA; FAINT AB We have performed a successful targeted search for a population of red, radio-quiet, and probably absorbed quasars. Radio-quiet, optically red ROSAT PSPC X-ray sources brighter than 1 x 10(-13) ergs cm(-2) s(-1) were searched for red (O-E >2.0, O less than or equal to 20) counterparts in the Automated Plate-measuring Machine catalog of Palomar Sky Survey objects. Of 45 objects for which we obtained adequate followup optical spectroscopy, we have found seven red quasars, five with alpha(opt) < -2. Their redshifts range from 0.06 to 0.31, and their luminosities are moderate, lying on the quasar/Seyfert boundary. These red quasars strengthen the case for a radio-quiet population that is the counterpart of the radio-loud red quasars found by Smith & Spinrad and Webster et al. Unidentified, fainter sources could increase the fraction of red quasars by up to a factor of 7. For the red quasars found here, the H alpha/H beta ratios, optical slope, and X-ray colors all indicate that they are absorbed by A(v) similar to 2 rather than having intrinsically red spectra. This amount of obscuration seems to hide similar to 1%-7% of quasars at a given observed flux or similar to 3%-20% when their fluxes are corrected to their intrinsic values. This size of population is consistent with earlier limits, with predicted values from Comastri et al., and is comparable with the rate found among radio-loud quasars. A large population of more heavily absorbed (A(v) = 5), fainter quasars equal in size to the blue population could exist without violating existing upper limits, which is in accord with the Comastri et al. predictions. C1 Chungnam Natl Univ, Taejon 305764, South Korea. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kim, DW (reprint author), Chungnam Natl Univ, Taejon 305764, South Korea. NR 65 TC 34 Z9 34 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 1999 VL 516 IS 1 BP 9 EP 17 DI 10.1086/307078 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 202NX UT WOS:000080660000002 ER PT J AU Romanowsky, AJ Kochanek, CS AF Romanowsky, AJ Kochanek, CS TI Constraints on H-o from the central velocity dispersions of lens galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE distance scale; gravitational lensing; quasars : individual (0957+561, PG 1115+080) ID GRAVITATIONAL LENS; SPHERICAL GALAXIES; ELLIPTIC GALAXIES; HUBBLE-CONSTANT; BLACK-HOLE; TIME-DELAY; DARK HALO; MODELS; PG-1115+080; PROFILES AB We employ Schwarzschild's method of the orbit modeling to constrain the mass profiles of the central lens galaxies in Q0957 + 561 and PG 1115 + 080. We combine the measured, central projected stellar velocity dispersions of these galaxies with the self-similar radial profiles of the rms velocity and of the Gauss Hermite moment h(4) observed in nearby galaxies for 0 less than or similar to R less than or similar to 2R(eff). For Q0957+561, we find a 16% uncertainty in the galaxy mass and formal 2 sigma Limits on the Hubble constant of H-o = 61(-15)(+13) km s(-1) Mpc(-1). For PG 115 + 080,we find that none of the viable lens models can be ruled out, so that H-o is not yet strongly constrained by this system. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Romanowsky, AJ (reprint author), Harvard Smithsonian Ctr Astrophys, MS-10,60 Garden St, Cambridge, MA 02138 USA. NR 64 TC 48 Z9 48 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 1999 VL 516 IS 1 BP 18 EP 26 DI 10.1086/307077 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 202NX UT WOS:000080660000003 ER PT J AU Worrall, DM Birkinshaw, M Remillard, RA Prestwich, A Tucker, WH Tananbaum, H AF Worrall, DM Birkinshaw, M Remillard, RA Prestwich, A Tucker, WH Tananbaum, H TI A multiwavelength study of the extreme AGN J2310-437 SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : individual (J2310-437); galaxies : active; X-rays : galaxies ID BL-LACERTAE OBJECTS; X-RAY-EMISSION; LUMINOSITY RADIO GALAXIES; COMPLETE SAMPLE; OPTICAL SPECTROSCOPY; PARENT POPULATION; EMITTING GAS; ROSAT HRI; CLUSTERS; BLAZARS AB We present new X-ray, radio, and optical data for the unusual galaxy/cluster system J2310-437. Our results confirm the presence of an active nucleus and suggest an interpretation as an anomalous BL Lac object of bulk relativistic Doppler factor <2, with an optically deficient radio to X-ray spectrum. The radio, optical, and soft X-ray flux densities could lie along a single power-law function, lacking the curvature typical of BL Lac objects. Compared with other known sources that may have comparable multifrequency spectra, J2310-437 is the most extreme. Its low isotropic optical/UV radiation is consistent with the intensity of external photons governing the electron spectral break through Compton cooling; in this source the external photon density would be too low to produce a spectral break below the X-ray. C1 Univ Bristol, Dept Phys, Bristol BS8 1TH, Avon, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Cambridge, MA 02139 USA. RP Worrall, DM (reprint author), Univ Bristol, Dept Phys, Bristol BS8 1TH, Avon, England. NR 53 TC 9 Z9 9 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 1999 VL 516 IS 1 BP 163 EP 176 DI 10.1086/307074 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 202NX UT WOS:000080660000014 ER PT J AU Gammie, CF Narayan, R Blandford, R AF Gammie, CF Narayan, R Blandford, R TI What is the accretion rate in NGC 4258? SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; galaxies : individual (NGC 4258); galaxies : nuclei; masers; X-rays : galaxies ID ADVECTION-DOMINATED ACCRETION; ACTIVE GALACTIC NUCLEI; KERR BLACK-HOLES; SPIRAL GALAXY NGC-4258; SAGITTARIUS-A-ASTERISK; ENERGY-DISTRIBUTIONS; MASER EMISSION; MOLECULAR DISK; CYGNUS X-1; H2O MASER AB We estimate the accretion rate (M) over dot onto the black hole in the nucleus of NGC 4258. The result is model dependent. We find that a thin disk that is flat out to greater than or equal to 2 x 10(3) GM/c(2) (M = black hole mass) and that has inclination equal to that of the masing disk must have (M) over dot similar or equal to 0.01 M-. yr(-1) for consistency with near-infrared data. A thin disk that is warped at similar to 10(3) GM/c(2) requires (M) over dot greater than or similar to 1.5 x 10(-4) M-. yr(-1) for consistency with near-infrared data. Reasonable warp models and the near-infrared data are not consistent with (M) over dot as low as the 7 x 10(-5) alpha M-. yr(-1) proposed by Neufeld & Maloney. An advection-dominated flow model combined with the X-ray data implies (M) over dot similar or equal to 0.01 M-. yr(-1). Consistency with a tight 22 GHz upper limit on the flux from the central source requires a transition radius of similar to(10-100)GM/c(2), although the 22 GHz upper limit may be relaxed by appeal to free-free absorption. Physical conditions in the observed VLBI jet features can also be related to conditions in the inner accretion how. We conclude with a list of observations that might further constrain (M) over dot. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Pasadena, CA 91125 USA. Isaac Newton Inst, Cambridge CB3 0EH, England. RP Gammie, CF (reprint author), Harvard Smithsonian Ctr Astrophys, MS-51,60 Garden St, Cambridge, MA 02138 USA. NR 69 TC 79 Z9 79 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 1999 VL 516 IS 1 BP 177 EP 186 DI 10.1086/307089 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 202NX UT WOS:000080660000015 ER PT J AU Barnes, SA Sofia, S Prosser, CF Stauffer, JR AF Barnes, SA Sofia, S Prosser, CF Stauffer, JR TI Rotation periods of late-type stars in the young open cluster IC 2602 SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; open clusters and associations : individual (IC 2602); stars : evolution; stars : pre-main-sequence; stars : rotation; stars : variables : other ID ALPHA-PERSEI CLUSTER; SOLAR-TYPE STARS; ANGULAR-MOMENTUM EVOLUTION; TIME-SERIES ANALYSIS; LOW-MASS STARS; LITHIUM ABUNDANCES; PLEIADES; IC-2602; SEQUENCE; DWARFS AB We present the results of a monitoring campaign aimed at deriving rotation periods for a representative sample of stars in the young (30 Myr) open cluster IC 2602. Rotation periods were derived for 29 of 33 stars monitored. The periods derived range from 0.2 days lone of the shortest known rotation periods of any single open cluster star) to about 10 days (which is almost twice as long as the longest period previously known for a cluster of this age). WE: are able to confirm eight previously known periods and derive 21 new ones, delineating the long-period end of the distribution. Despite our sensitivity to longer periods, we do not detect any variables with periods longer than about 10 days. The combination of these data with those for IC 2391, an almost identical cluster, leads to the following conclusions: (1) The fast rotators in a 30 Myr cluster are distributed across the entire 0.5 < B-V < 1.6 color range. (2) Six stars in our sample are slow rotators, with periods longer than 6 days. (3) The amplitude of variability depends on both the color and the period. The dependence on the latter might be important in understanding the selection effects in the currently available rotation period database and in planning future observations. (4) The interpretation of these data in terms of theoretical models of rotating stars suggests both that disk interaction is the norm rather than the exception in young stars and that disk-locking times range from zero to a few Myr. C1 Yale Univ, Dept Astron, New Haven, CT 06520 USA. Kitt Peak Natl Observ, Natl Opt Astron Observ, Tucson, AZ 85726 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Barnes, SA (reprint author), Yale Univ, Dept Astron, Box 208101, New Haven, CT 06520 USA. NR 41 TC 50 Z9 50 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 1999 VL 516 IS 1 BP 263 EP 275 DI 10.1086/307091 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 202NX UT WOS:000080660000022 ER PT J AU Laming, JM Drake, JJ AF Laming, JM Drake, JJ TI Stellar coronal abundances. VI. The first ionization potential effect and xi Bootis A - Solar like anomalies at intermediate-activity levels SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : visual; stars : abundances; stars : coronae; ultraviolet : stars ID SPECTRAL-LINE INTENSITIES; ELECTRON-IMPACT EXCITATION; ATOMIC DATA; ELEMENTAL ABUNDANCES; COLLISION STRENGTHS; EUVE OBSERVATIONS; RATE COEFFICIENTS; EPSILON-ERIDANI; COOL STARS; IRON AB Lines from different elements in the Extreme-Ultraviolet Explorer spectra of the corona of the intermediate-activity star xi Bootis A have been analyzed. Assuming that a photospheric composition for the plasma is responsible for the observed coronal emission, emission measures derived from lines of elements with low first ionization potentials (FIPs) are systematically higher than emission measures derived from lines formed at similar temperatures but due to elements with high FIPs. This problem is alleviated by adopting a "coronal" abundance pattern similar to that which appears to characterize the average solar corona. We interpret these results as evidence that the same FIP-based compositional fractionation mechanism at work in the solar outer atmosphere is also operational in the coronae of significantly more active stars such as xi Boo A. C1 SFA Inc, Largo, MD 20774 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Laming, JM (reprint author), SFA Inc, Largo, MD 20774 USA. NR 70 TC 39 Z9 39 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 1999 VL 516 IS 1 BP 324 EP 334 DI 10.1086/307112 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 202NX UT WOS:000080660000029 ER PT J AU Wood, K Crosas, M Ghez, A AF Wood, K Crosas, M Ghez, A TI GG Tauri's circumbinary disk: Models for near-infrared scattered-light images and (CO)-C-13 (J=1 -> 0) line profiles SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : visual; circumstellar matter; radiative transfer; stars : individual (GG Tauri); stars : pre-main-sequence ID YOUNG STELLAR OBJECTS; SPECTRAL ENERGY-DISTRIBUTIONS; CIRCUMSTELLAR DISKS; SIZE DISTRIBUTION; ACCRETION DISKS; STARS; DUST; ENVELOPES; RADIATION; AURIGAE AB We describe models that reproduce the observed near-IR scattered-light images and (CO)-C-13 (J = 1-->0) line profiles from the GG Tau circumbinary disk. The observed extent of the scattered-light images requires a 0.13 M. flared circumbinary disk (as determined from millimeter observations), an inner cleared region of 200 AU, and scale height of 16.6 AU at the disk's inner edge. To reproduce the brightness distribution, we require extinction of the illuminating starlight prior to scattering within the circumbinary disk. This extinction is obtained by including the effects of small circumstellar disks that are coplanar with the circumbinary disk. Further, we find that the effects of geometry and illumination allows the observed scattered-light pattern to be reproduced with a dust grain distribution that fits data from other Taurus-Auriga circumstellar environments. This indicates that unless geometries and illuminations are known, great care must be taken when attempting to determine grain properties from analysis of scattered-light images. The observed (CO)-C-13 line profiles are reproduced using the same geometry adopted for the near-IR modeling. However, we find that the (CO)-C-13 abundance is Power than in the diffuse interstellar medium, in agreement with previous investigations indicating CO depletion in circumstellar environments. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Wood, K (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 35 TC 15 Z9 15 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 1999 VL 516 IS 1 BP 335 EP 341 DI 10.1086/307104 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 202NX UT WOS:000080660000030 ER PT J AU Quataert, E Narayan, R AF Quataert, E Narayan, R TI On the energetics of advection-dominated accretion flows SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; MHD; turbulence ID SAGITTARIUS A-ASTERISK; BLACK-HOLES; OPTICALLY THIN; CYGNUS X-1; DISKS; SPECTRUM; MODEL; TURBULENCE; RADIATION AB Using mean field MHD, we discuss the energetics of optically thin, two-temperature, advection-dominated accretion hows (ADAFs). If the magnetic field is tangled and roughly isotropic, flux freezing is insufficient to maintain the field in equipartition with the gas. In this case we expect a fraction of the energy generated by shear in the how to be used to build up the magnetic field strength as the gas flows in; the remaining energy heats the particles. We argue that strictly equipartition magnetic fields are incompatible with a priori reasonable levels of particle heating; instead, the plasma beta in ADAFs (= gas pressure divided by magnetic/turbulent pressure) is likely to be greater than or similar to 5; correspondingly, the viscosity parameter alpha is likely to be less than or similar to 0.2. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Quataert, E (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 29 TC 26 Z9 25 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 1999 VL 516 IS 1 BP 399 EP 410 DI 10.1086/307097 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 202NX UT WOS:000080660000037 ER PT J AU Meixner, M Ueta, T Dayal, A Hora, JL Fazio, G Hrivnak, BJ Skinner, CJ Hoffmann, WF Deutsch, LK AF Meixner, M Ueta, T Dayal, A Hora, JL Fazio, G Hrivnak, BJ Skinner, CJ Hoffmann, WF Deutsch, LK TI A mid-infrared imaging survey of proto-planetary nebula candidates SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE circumstellar matter; infrared : ISM : continuum; ISM : structure; stars : AGB and post-AGB; stars : mass loss ID ASYMPTOTIC GIANT BRANCH; PROTOPLANETARY NEBULAE; IRAS SOURCES; CO OBSERVATIONS; RED RECTANGLE; BIPOLAR; DUST; SPECTRA; STARS; OBJECTS AB We present the data from a mid-infrared (MIR) imaging survey of 66 proto-planetary nebula candidates using two MIR cameras (MIRAC2 and Berkcam) at the NASA Infrared Telescope Facility and the United Kingdom Infrared Telescope. The goal of this survey is to determine the size, flux, and morphology of the MIR emission regions, which sample the inner regions of the circumstellar dust shells of proto-planetary nebulae. We imaged these proto-planetary nebulae with narrowband filters (Delta lambda/lambda similar to 10%) at wavelengths of notable dust features. With our typical angular resolution of 1", we resolve 17 sources, find 48 objects unresolved, and do not detect one source. For several sources we checked optical and infrared associations and positions of the sources. In table format, we list the size and flux measurements for all of the detected objects and show figures of all of the resolved sources. The proto-planetary nebula candidate sample includes, in addition to the predominant proto-planetary nebulae, extreme asymptotic giant branch stars, young planetary nebulae, a supergiant, and a luminous blue variable. We find that dust shells that are cooler (T similar to 150 K) and brighter in the infrared are more easily resolved. Eleven of the seventeen resolved sources are extended and fall into one of two types of MIR morphological classes: core/elliptical or toroidal. Core/elliptical structures show unresolved cores with lower surface brightness elliptical nebulae. Toroidal structures show limb-brightened peaks suggesting equatorial density enhancements. We argue that core/ellipticals have denser dust shells than toroidals. C1 Univ Illinois, Dept Astron, Urbana, IL 61801 USA. CALTECH, JPL, IPAC, Pasadena, CA 91125 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Boston Univ, Dept Astron CAS 519, Boston, MA 02215 USA. RP Univ Illinois, Dept Astron, MC-221, Urbana, IL 61801 USA. EM meixner@astro.uiuc.edu; ueta@astro.uiuc.edu; adayal@ipac.caltech.edu; jhora@cfa.harvard.edu; gfazio@cfa.harvard.edu; bhrivnak@exodus.valpo.edu; whoffmann@as.arizona.edu; deutschl@bu.edu OI Hora, Joseph/0000-0002-5599-4650 NR 64 TC 123 Z9 123 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 EI 1538-4365 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD MAY PY 1999 VL 122 IS 1 BP 221 EP 242 DI 10.1086/313215 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 213XD UT WOS:000081297800009 ER PT J AU Drake, JJ AF Drake, JJ TI The response of the EUVE scanning and deep survey telescopes to coronal plasma radiative loss SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE stars : activity; stars : coronae; stars : late-type; X-rays : stars ID EXTREME-ULTRAVIOLET-EXPLORER; LOCAL INTERSTELLAR-MEDIUM; RIGHT-ANGLE PROGRAM; ALL-SKY SURVEY; SOLAR ATMOSPHERE; COOL STARS; ABUNDANCE VARIATIONS; ENERGETIC PARTICLES; ALPHA-CENTAURI; WHITE-DWARFS AB Over half of the sources detected in the Extreme-Ultraviolet Explorer (EUVE) All-Sky Survey and Deep Survey (50-760 Angstrom) that have known optical counterparts are late-type stars. The EUV emission from late-type stars is thought to originate from hot, collisionally dominated, optically thin plasmas, with temperatures ranging between 10(5) and 10(8) K, that are confined by magnetic structures analogous to those observed on the Sun. The different filters providing wavelength discrimination used on the EUVE scanning telescopes are sensitive to emission from optically thin plasmas with temperatures throughout this range. We have investigated the responses of each of the EUVE photometric instruments as a function of plasma temperature for different interstellar medium column densities. The results will be of use for interpreting EUVE photometric count rates for astrophysical collisionally dominated, optically thin plasma sources. The different sources of uncertainty entering into these types of calculation are reviewed. Three issues of special importance not generally considered in the interpretation of EUV observations of radiative loss are emphasized: (1) current radiative loss models are incomplete in their treatment of ionization states with n = 2 and n = 3 ground states; (2) the interstellar medium neutral and ionized He absorbing columns are generally unknown and represent potentially large uncertainties in the interpretation of EUV photometry; and (3) plasma chemical composition has a large influence on the shape of radiative loss curves, photometric flux calibrations, and derived emission measures. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Drake, JJ (reprint author), Harvard Smithsonian Ctr Astrophys, MS-3,60 Garden St, Cambridge, MA 02138 USA. NR 71 TC 6 Z9 6 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD MAY PY 1999 VL 122 IS 1 BP 269 EP 297 DI 10.1086/313206 PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 213XD UT WOS:000081297800012 ER PT J AU Schwartz, MK Boness, DJ Schaeff, CM Majluf, P Perry, EA Fleischer, RC AF Schwartz, MK Boness, DJ Schaeff, CM Majluf, P Perry, EA Fleischer, RC TI Female-solicited extrapair matings in Humboldt penguins fail to produce extrapair fertilizations SO BEHAVIORAL ECOLOGY LA English DT Article DE epiphenomenon; extrapair fertilization; extrapair mating; female choice; Humboldt penguins; mate appraisal; Spheniscus humboldti ID PREDOMINANTLY MONOGAMOUS BIRD; SEXY SON HYPOTHESIS; PAIR COPULATIONS; NORTHERN FULMAR; TREE SWALLOWS; TAENIOPYGIA-GUTTATA; EASTERN BLUEBIRDS; GENETIC-STRUCTURE; HIRUNDO-RUSTICA; DNA AB The study reported in this paper demonstrated that Humboldt penguins at Punta San Juan, Peru, despite forming pair-bonds, are not strictly monogamous in their mating behavior: 19.2% of the study males and 30.7% of the study females (21 nests) engaged in extrapair copulations. The total number of completed matings observed during the course of this study was 106, of which 17.9% were extrapair copulations. Using DNA fingerprinting we demonstrated that none of these extrapair copulations resulted in extrapair fertilizations; all 49 offspring were attributed to the putative father: Location of copulations suggested that females solicited these extrapair copulations because 89.2% of Humboldt penguin within-pair copulations occurred at the home burrow, yet extrapair copulations took place at a different location based on the sex of the penguin. Extrapair copulations by males occurred at their nest. whereas females conducted 92% of their extrapair copulations away from the nest. These results are most consistent with mate-appraisal and epiphenomenal hypotheses. C1 Smithsonian Inst, Natl Zool Pk, Dept Zool Res, Washington, DC 20008 USA. RP Schwartz, MK (reprint author), Univ Montana, Wildlife Biol Program, Missoula, MT 59812 USA. RI Schwartz, Michael/C-3184-2014; OI Schwartz, Michael/0000-0003-3521-3367; Schaeff, Catherine/0000-0003-3728-9402 NR 69 TC 24 Z9 24 U1 5 U2 19 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 1045-2249 J9 BEHAV ECOL JI Behav. Ecol. PD MAY-JUN PY 1999 VL 10 IS 3 BP 242 EP 250 DI 10.1093/beheco/10.3.242 PG 9 WC Behavioral Sciences; Biology; Ecology; Zoology SC Behavioral Sciences; Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Zoology GA 208WP UT WOS:000081015100005 ER PT J AU Greenberg, R Parvosudov, V Sterling, J Kozlenko, A Kontorshchikov, V AF Greenberg, R Parvosudov, V Sterling, J Kozlenko, A Kontorshchikov, V TI Tits, warblers, and finches: Foliage-gleaning birds of nearctic and palearctic boreal forests SO CONDOR LA English DT Article DE boreal forests; community convergence; community structure; continental comparison; foliage-gleaning bird; Fringilla; warblers ID PATTERNS; COMMUNITIES; SPECIATION; DIVERSITY AB We describe two major patterns of abundance of different types of canopy foliage-gleaning birds at four sites (northwestern Canada, eastern Canada, European Russia, and central Siberia) in boreal forest. First, because of the extreme numerical dominance and breadth of habitat use of the Chaffinch (Fringilla coelebs), the European Russian sites stand as outliers to the relationships between the number of species and the abundance of all foliage-gleaning birds, as well as to more detailed patterns of the composition of the foliage-gleaner guild. The Chaffinch is one of the few canopy foliage-gleaning birds in temperate forests that is abundant in agricultural habitats during the nonbreeding season, which probably allowed a rapid expansion of its range and growth in abundance with the advent of farming in Europe. The second pattern emerges when the European Russian sites are excluded from analyses: the proportional abundance and number of species of warblers or warbler-like birds were positively related to overall abundance of foliage gleaners. This suggests that warblers prosper when there is high resource productivity during the breeding season. A possible resolution between the patterns found in European Russia and the other boreal forest sites may be that Fringilla are functionally equivalent to warblers and have essentially replaced warblers to achieve their high abundance. The patterns of relative abundance give support to both the Resource Seasonality Hypothesis (warblers versus tits), and the Ecological Replacement Hypothesis (Fringilla versus warblers) as explanations for shifts in the numerical dominance of different types of foliage gleaners in different regions. C1 Smithsonian Migratory Ctr, Washington, DC 20008 USA. Ohio State Univ, Dept Zool, Columbus, OH 43210 USA. Smithsonian Migratory Bird Ctr, Washington, DC 20008 USA. RP Greenberg, R (reprint author), Smithsonian Migratory Ctr, Natl Zool Pk, Washington, DC 20008 USA. NR 29 TC 6 Z9 6 U1 0 U2 3 PU COOPER ORNITHOLOGICAL SOC PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0010-5422 J9 CONDOR JI Condor PD MAY PY 1999 VL 101 IS 2 BP 299 EP 310 DI 10.2307/1369993 PG 12 WC Ornithology SC Zoology GA 191DD UT WOS:000080005700011 ER PT J AU Laurance, WF Gascon, C Rankin-de Merona, JM AF Laurance, WF Gascon, C Rankin-de Merona, JM TI Predicting effects of habitat destruction on plant communities: A test of a model using Amazonian trees SO ECOLOGICAL APPLICATIONS LA English DT Article DE Amazonia; deforestation; extinction; habitat clearing; habitat fragmentation; rainforest trees; population density; random-clearing model; species richness; tropical forests, Brazil ID FOREST FRAGMENTATION; EXTINCTION; DIVERSITY; DEFORESTATION; CONSERVATION; RECRUITMENT; PATTERN; BRAZIL; AREA AB We devised a "random-clearing model" to predict effects of habitat loss on plant communities and populations. The model yields the probability that a species will be extirpated by land clearing, based on only two parameters: its density and the percentage of the landscape that has been cleared. It can also be used to predict species richness of plant communities following clearing, so long as densities of individual species are known. We tested the model using data on the distributions of 200 tree species (greater than or equal to 10 cm dbh) within two 9-ha experimental landscapes in central Amazonia. Deforestation levels ranging from 20% to 99% of the landscape were simulated randomly, with the actual persistence of each species being the number of times it remained in the landscape after 1000 runs. The model was effective in all cases, explaining 83-99% of the total variability in species persistence on each plot. Species' distribution patterns explained some residual variation in persistence but were of negligible importance compared to the predictions of the model. We also used the model to predict species richness, simulating both random and realistically contagious patterns of deforestation. Again, the model was highly effective, explaining 96% to 98% of the total variation in richness. Surprisingly, there was little difference in richness between random and contagious clearing patterns. These results suggest that, at least at the limited spatial scale of our analysis, the effects of deforestation on plant persistence and richness can be predicted using a simple model that assumes random species distributions and deforestation patterns. The model makes four predictions: (1) Density has an overriding influence on the susceptibility of species to clearing, while distribution patterns are usually of much lesser importance. (2) The relationship between density and persistence is nonlinear. (3) Rare species (less than or equal to 1 tree/ha) become exceptionally vulnerable in heavily degraded landscapes and in small forest remnants. (4) The distinction between high (e.g., 95%) and very high (e.g., 99%) levels of habitat clearing in terms of species persistence is often dramatic. C1 Natl Inst Res Amazon, Biol Dynam Forest Fragments Project, BR-69011970 Manaus, Amazonas, Brazil. Smithsonian Inst, Natl Museum Amer Hist, Biodivers Program, Washington, DC 20560 USA. RP Laurance, WF (reprint author), Natl Inst Res Amazon, Biol Dynam Forest Fragments Project, CP 478, BR-69011970 Manaus, Amazonas, Brazil. RI Laurance, William/B-2709-2012 NR 33 TC 19 Z9 21 U1 0 U2 8 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD MAY PY 1999 VL 9 IS 2 BP 548 EP 554 DI 10.2307/2641143 PG 7 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 213AQ UT WOS:000081250200021 ER PT J AU Robertson, DR Swearer, SE Kaufmann, K Brothers, EB AF Robertson, DR Swearer, SE Kaufmann, K Brothers, EB TI Settlement vs. environmental dynamics in a pelagic-spawning reef fish at Caribbean Panama SO ECOLOGICAL MONOGRAPHS LA English DT Article DE Caribbean; environmental dynamics; labrid fish; lunar effects; pelagic spawning; seasonality; settlement dynamics; Thalassoma; tidal effects; wind effects ID GREAT-BARRIER-REEF; WRASSE THALASSOMA-BIFASCIATUM; PLANKTONIC LARVAL DURATION; LIFE-HISTORY TRAITS; CORAL-REEFS; RECRUITMENT DYNAMICS; WEST-INDIES; EPINEPHELUS-STRIATUS; NASSAU GROUPER; PATTERNS AB How are the dynamics of the settlement of pelagic larvae of marine shore organisms into benthic habitats affected by larval production and mortality dynamics, and by environmental (wind and tidal) control of settler delivery? We examined the dynamics of reproduction of the pelagic-spawning fish Thalassoma bifasciatum from that perspective at San Bias, Caribbean Panama. During April-June 1993, similar to 75% of females spawned each day, with mean output per female per day at about one-third the potential maximum. Output peaked several days before the new and full moon, when tides were high during the afternoon spawning period. Daily fluctuations in output were weakly correlated with light (+), swell (-), and onshore wind (-) on preceding days. Settler production (determined from otolith back calculations of settlers' fertilization dates) peaked during the wet season (May-November), when winds were light and variable, spawning-period tidal heights were moderate to low, and tidal flows were off-reef at night. These conditions correspond to when mast settlement occurs. Settler production was minimal during the dry season (January-March), when onshore trade winds were strong and consistent, and tidal conditions were the reverse of those in the wet season. Settlement usually occurred in one variably timed pulse per lunar cycle, around the new moon. Variation in monthly settlement strength over 11 yr (1986-1996) was unrelated to onshore wind stress during either settler arrival or settler production. The daily dynamics of settlement were unrelated to the concurrent dynamics of wind or tides, or wind dynamics up to a week before settlement. Settler production was much less continuous than spawning. Wet season settler-production dynamics were unrelated to tidal dynamics, but (weakly) negatively related to onshore wind stress. Although the dynamics of settler production and settlement were similar, bouts of settler production were about twice as long as bouts of settlement. The average lunar patterns of settler production and observed spawning were similar (weakly bimodal). Settlers produced during different lunar phases differed in the length and variability of their pelagic larval durations (PLDs). Fish with different PLDs all tended to settle around the new moon. Weakly semilunar spawning may reflect effects of weak tidal influences on egg survivorship, or of environmental constraints on adults' spawning capacity that also limit spawning to well below the potential maximum. Dry season trade winds may produce the seasonal low of settlement by depressing spawning or forcing the onshore transport of eggs and larvae. If settlement is transport-dependent, weak variable winds may have little effect on currents during the wet season, or local geography may limit such effects; tidal dynamics may not affect wet-season settlement dynamics because small (<0.6 m) tides produce weak flows. Alternatively, settlement may not be dependent on transport mechanisms. Short-term settlement dynamics result from both the dynamics of larval survival (as most larvae have near-mean PLDs) and larvae delaying or advancing settlement to settle around the new moon. Larvae spawned at different lunar phases have different patterns of variation in their PLDs but achieve similar relative settlement success. Larvae with extended PLDs may not suffer low settlement success because the inevitable age-dependent decline in survival has smaller effects on relative settlement success than does large monthly variation in the survivorship of fish spawned during different lunar phases. C1 Smithsonian Trop Res Inst Panama, Unit 0948, Balboa, Panama. Univ Calif San Diego, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA USA. EFS Consultants, Ithaca, NY 14850 USA. RP Smithsonian Trop Res Inst Panama, Unit 0948, Apartado 2072, Balboa, Panama. EM robertsr@naos.si.edu OI SWEARER, STEPHEN/0000-0001-6381-9943 NR 90 TC 57 Z9 58 U1 4 U2 20 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0012-9615 EI 1557-7015 J9 ECOL MONOGR JI Ecol. Monogr. PD MAY PY 1999 VL 69 IS 2 BP 195 EP 218 DI 10.1890/0012-9615(1999)069[0195:SVEDIA]2.0.CO;2 PG 24 WC Ecology SC Environmental Sciences & Ecology GA 194CY UT WOS:000080175600004 ER PT J AU Lavoie, DM Smith, LD Ruiz, GM AF Lavoie, DM Smith, LD Ruiz, GM TI The potential for intracoastal transfer of non-indigenous species in the ballast water of ships SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE ballast water; invasion; non-indigenous; survivorship; intracoastal; domestic shipping ID SAN-FRANCISCO BAY; COPEPOD PSEUDODIAPTOMUS-INOPINUS; CLAM POTAMOCORBULA-AMURENSIS; BIOLOGICAL INVASIONS; NARRAGANSETT-BAY; ACARTIA-TONSA; RHODE-ISLAND; CERATIUM-HIRUNDINELLA; REMARKABLE INVASION; MARINE ORGANISMS AB A principal mechanism for the transfer of non-indigenous species among aquatic ecosystems has been through the movement of ships' ballast water. To date, most ballast water studies have focused on the transoceanic movement of organisms while ignoring the potential for spread by intracoastal traffic. This study measured the transfer of estuarine and coastal species by domestic ship traffic between Somerset, Massachusetts and Norfolk, Virginia, U.S.A. Plankton diversity and abundance in the ballast water of a coal carrier at the beginning and end of seven replicate voyages were estimated. These data, collected over a 1-year period, were used to (1) characterize plankton assemblages in the ballast water, (2) assess survivorship of ballasted organisms for the voyages by comparing initial and final abundances, and (3) test for differences in survival as a function of voyage or taxonomic group. A diverse assemblage of organisms was transported intracoastally that was dominated by dinoflagellates, diatoms and copepods. In four of seven voyages, total abundance declined significantly over the 36-h journey; however, considerable within- and among-voyage variation in numerical response among major taxonomic groups was observed. Despite a general decline in abundance, millions of organisms nevertheless survived each voyage and were released into the receiving harbor. These data indicate that ballast water carried by domestic ships is potentially an important vector for transferring aquatic non-indigenous and native nuisance species. Thus, future management decisions concerning ballast water transport should consider the role of domestic traffic in promoting invasions. C1 Northeastern Univ, Ctr Marine Sci, Nahant, MA 01908 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Smith, LD (reprint author), Northeastern Univ, Ctr Marine Sci, Nahant, MA 01908 USA. OI Ruiz, Gregory/0000-0003-2499-441X NR 64 TC 78 Z9 83 U1 2 U2 17 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0272-7714 J9 ESTUAR COAST SHELF S JI Estuar. Coast. Shelf Sci. PD MAY PY 1999 VL 48 IS 5 BP 551 EP 564 DI 10.1006/ecss.1999.0467 PG 14 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 207PB UT WOS:000080944300004 ER PT J AU Backwell, PRY Jennions, MD Christy, JH Passmore, NI AF Backwell, PRY Jennions, MD Christy, JH Passmore, NI TI Female choice in the synchronously waving fiddler crab Uca annulipes SO ETHOLOGY LA English DT Article AB In the fiddler crab, Uca annulipes, males attract receptive females into their burrows by waving their greatly enlarged major claw. We have previously shown that males clustered around a female wave in close synchrony. Females may have a preference for leading signals and synchronised waving may arise as an epiphenomenon of competition between males to signal first. Indeed, the males in clusters that females approach and visit in their burrows are more likely to produce leading waves than are their neighbours. Here we document two other differences in the waving behaviour of visited males and their neighbours. First, visited males complete the downward component of the wave more rapidly than their neighbours. Second, the interval between the end of one wave and the start of the next is shorter for visited males. How can waving be synchronous if visited males wave faster than their neighbours? While only 9% (40/431) of waves by neighbours did not overlap those of the visited male, 22% (110/501) of visited male waves did not overlap the wave of a focal neighbour (111 visited male-neighbour dyads). Hence, while overlapping waves are nearly synchronous, visited males produce additional, 'nonoverlapping' waves that result in a higher wave rate than that of their neighbours. C1 Smithsonian Trop Res Inst, Panama City, Panama. Univ Witwatersrand, Dept Zool, Johannesburg, South Africa. RP Backwell, PRY (reprint author), Smithsonian Trop Res Inst, Unit 0948, APO, AA 34002 USA. RI Jennions, Michael/C-7560-2009; Backwell, Patricia/C-8883-2009 OI Jennions, Michael/0000-0001-9221-2788; NR 11 TC 59 Z9 61 U1 0 U2 9 PU BLACKWELL WISSENSCHAFTS-VERLAG GMBH PI BERLIN PA KURFURSTENDAMM 57, D-10707 BERLIN, GERMANY SN 0179-1613 J9 ETHOLOGY JI Ethology PD MAY PY 1999 VL 105 IS 5 BP 415 EP 421 DI 10.1046/j.1439-0310.1999.00387.x PG 7 WC Psychology, Biological; Behavioral Sciences; Zoology SC Psychology; Behavioral Sciences; Zoology GA 198RN UT WOS:000080438000004 ER PT J AU Norris, RD Huber, BT Self-Trail, J AF Norris, RD Huber, BT Self-Trail, J TI Synchroneity of the K-T oceanic mass extinction and meteorite impact: Blake Nose, western North Atlantic SO GEOLOGY LA English DT Article ID CRETACEOUS-TERTIARY BOUNDARY; PLANKTONIC-FORAMINIFERA; CHICXULUB IMPACT; EL-KEF; YUCATAN AB A 10-cm-thick layer of green spherules occurs precisely at the biostratigraphic boundary between the Cretaceous and Paleogene (K-T boundary) at Ocean Drilling Program Site 1049 (lat 30 degrees 08'N, long 76 degrees 06'W), The spherulitic layer contains abundant rock fragments (chalk, limestone, dolomite, chert, mica books, and schist) as well as shocked quartz, abundant large Cretaceous planktic foraminifera, and rounded clasts of clay as long as 4 mm interpreted as altered tektite glass probably derived from the Chicxulub impact structure, Most of the Cretaceous foraminifera present above the spherule layer are not survivors since small specimens are conspicuously rare compared to large individuals. Instead, the Cretaceous taxa in Paleocene sediments are thought to be reworked. The first Paleocene planktic foraminifera and calcareous nannofossil species are recorded immediately above the spherule bed, the upper part of which contains an iridium anomaly. Hence, deposition of the impact ejecta exactly coincided with the biostratigraphic K-T boundary and demonstrates that the impact event was synchronous with the evolutionary turnover in the oceans. These results are consistent with a reanalysis of the biostratigraphy of the K-T boundary stratotype, which argues that shallow-marine K-T boundary sections are not biostratigraphically more complete than deep-sea K-T boundary sites. C1 Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Smithsonian Inst, Dept Paleobiol, Washington, DC 20560 USA. US Geol Survey, Reston, VA 20192 USA. RP Norris, RD (reprint author), Woods Hole Oceanog Inst, MS-23, Woods Hole, MA 02543 USA. NR 22 TC 74 Z9 74 U1 0 U2 5 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD MAY PY 1999 VL 27 IS 5 BP 419 EP 422 DI 10.1130/0091-7613(1999)027<0419:SOTKTO>2.3.CO;2 PG 4 WC Geology SC Geology GA 193QF UT WOS:000080147100009 ER PT J AU Rhodes, GM Ali, JR Hailwood, EA King, C Gibson, TG AF Rhodes, GM Ali, JR Hailwood, EA King, C Gibson, TG TI Magnetostratigraphic correlation of Paleogene sequences from northwest Europe and North America SO GEOLOGY LA English DT Article ID SEA-LEVEL HISTORY; GLOBAL CYCLE CHART; EVERY OCCASION; EVENT AB Using all available biostratigraphic information and our own extensive magnetostratigraphic database, we have attempted to assess the synchronicity of depositional cycles recorded in the Paleogene epicontinental deposits on both sides of the North Atlantic as stage two of a four-stage global assessment of the eustatic sea-level model. Our conclusion is that the depositional histories of the U.S. Gulf of Mexico-Atlantic coastal plain and the North Sea basin show many similarities, on a variety of time scales, over the interval 60-46 Ma. Considering the tectonic imprint of the northeast Atlantic opening on the North Sea basin sea-level record far part of this time, it must give some weight to the claim that eustasy is the dominant mechanism controlling deposition on passive continental margins. C1 Univ Southampton, Dept Oceanog, Southampton SO14 3ZH, Hants, England. Univ Hong Kong, Dept Earth Sci, Hong Kong, Hong Kong. Core Magnet, Sedbergh LA10 5JS, Cumbria, England. Univ Greenwich, Sch Earth & Environm Sci, Chatham ME4 4TB, Kent, England. Smithsonian Institut, Dept Paleobiol, Washington, DC 20540 USA. RP Rhodes, GM (reprint author), Mine Act, Ajuda Popular Noruega, Rua Fernao Mendes Pinto 54, Luanda, Angola. RI Ali, Jason/A-2738-2010 NR 27 TC 10 Z9 10 U1 0 U2 0 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD MAY PY 1999 VL 27 IS 5 BP 451 EP 454 DI 10.1130/0091-7613(1999)027<0451:MCOPSF>2.3.CO;2 PG 4 WC Geology SC Geology GA 193QF UT WOS:000080147100017 ER PT J AU Gomez, NE Witte, L Hartmann, T AF Gomez, NE Witte, L Hartmann, T TI Chemical defense in larval tortoise beetles: Essential oil composition of fecal shields of Eurypedus nigrosignata and foliage of its host plant, Cordia curassavica. SO JOURNAL OF CHEMICAL ECOLOGY LA English DT Article DE Eurypedus nigrosignata; tortoise beetle; Chrysomelidae; Cordia curassavica; Boraginaceae; lower terpenes; essential oil; chemical type; chemotype; fecal shield; chemical defense ID PAROPSIS-ATOMARIA; NASUTITERMES-PRINCEPS; GROWTH; RESIN; CHRYSOMELIDAE; HYMENOPTERA; COLEOPTERA; SECRETION; BEHAVIOR; PARASITE AB Larvae of the tortoise beetle Eurypedus nigrosignata construct fecal shields using cast skins and fecal strands. Survival of larvae with intact shields was higher in the field than for larvae with shields removed. In the laboratory, E. nigrosignata feculae had a deterrent effect on feeding in the ant Myrmica rubra as did an extract of the host plant, Cordia curassavica. Three chemical types were identified in the host-plant foliage and were named beta-terpinene, alpha-pinene, and sabinene, depending on their mono- and sesquiterpene composition. This is the first report of lower terpenes (essential oils) in foliage of Cordia. Fecal shields of E. nigrosignata displayed the same terpene pattern as larval host-plant leaves. The absolute concentration of mono- and sesquiterpenes in the dorsal fecal shield depended on the plant chemical type and tended to decrease with larval age. No oxidation or detoxification products of ingested terpenes were detected in the larval fecula, indicating that the chemical composition of the larval fecal shield is influenced primarily by the host-plant secondary chemistry. C1 Smithsonian Trop Res Inst, Balboa, Panama. Tech Univ Braunschweig, Inst Pharmazeut Biol, D-38106 Braunschweig, Germany. RP Gomez, NE (reprint author), Smithsonian Trop Res Inst, POB 2072, Balboa, Panama. NR 68 TC 37 Z9 38 U1 3 U2 13 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0098-0331 J9 J CHEM ECOL JI J. Chem. Ecol. PD MAY PY 1999 VL 25 IS 5 BP 1007 EP 1027 DI 10.1023/A:1020821507014 PG 21 WC Biochemistry & Molecular Biology; Ecology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology GA 195TG UT WOS:000080267800002 ER PT J AU Reid, JW Strayer, DL McArthur, JV Stibbe, SE Lewis, JJ AF Reid, JW Strayer, DL McArthur, JV Stibbe, SE Lewis, JJ TI Rheocyclops, a new genus of copepods from the southeastern and central USA (Copepoda : Cyclopoida : Cyclopidae) SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article AB The new genus Rheocyclops is proposed to accommodate the cyclopoid copepods Diacyclops virginianus Reid, from Virginia, and the new species R. carolinianus from South Carolina, R. talladega and R. hatchiensis ham Alabama, and R. indiana from indiana, U.S.A. Most species were collected from the hyporheic zones of stream beds, except R. indiana which was found in a drip pool in a cave. The new genus is distinguished by a combination of characters: anal operculum produced; antennule 11-segmented; antenna lacking exopodite seta; rami of legs 1-4 all 3-segmented, pr some rami 2-segmented; leg 5 with proximal segment fused to somite and reduced to small protrusion bearing seta inserted near distal (free) segment, and free segment cylindrical with 2 terminal setae. C1 Smithsonian Inst, Natl Museum Amer Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. Inst Ecosyst Studies, Millbrook, NY 12545 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Reid, JW (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RI Strayer, David/H-3788-2011 NR 27 TC 15 Z9 15 U1 0 U2 0 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 USA SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD MAY PY 1999 VL 19 IS 2 BP 384 EP 396 DI 10.2307/1549246 PG 13 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 196GC UT WOS:000080299800020 ER PT J AU Kurin, R AF Kurin, R TI Time has come today (Response to Konrad Kostlin) SO JOURNAL OF FOLKLORE RESEARCH LA English DT Article; Proceedings Paper CT Symposium on Public Folkore - Forms of Intellectual Practice in Society CY JUL, 1998 CL HOMBURG, GERMANY C1 Smithsonian Inst, Washington, DC 20560 USA. RP Kurin, R (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU INDIANA UNIV PI BLOOMINGTON PA FOLKLORE INST 504 NORTH FESS ST, BLOOMINGTON, IN 47405 USA SN 0737-7037 J9 J FOLKLORE RES JI J. Folk. Res. PD MAY-DEC PY 1999 VL 36 IS 2-3 BP 299 EP 302 PG 4 WC Folklore SC Arts & Humanities - Other Topics GA 265YK UT WOS:000084273700025 ER PT J AU Galvin, AB Kohl, JL AF Galvin, AB Kohl, JL TI Whole Sun Month at solar minimum: An introduction SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article AB The Whole Sun Month was a collaborative project of the IACG Campaign 4 and the SOHO Joint Observing Programs to characterize and model the structure of the global corona during solar minimum conditions. This introduction provides a brief description of the campaign objectives, the missions, and observatories involved and highlights some of the scientific results reported elsewhere in this special section. C1 Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Galvin, AB (reprint author), Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. NR 8 TC 13 Z9 13 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 1999 VL 104 IS A5 BP 9673 EP 9678 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BQ UT WOS:000080058600001 ER PT J AU Biesecker, DA Thompson, BJ Gibson, SE Alexander, D Fludra, A Gopalswamy, N Hoeksema, JT Lecinski, A Strachan, L AF Biesecker, DA Thompson, BJ Gibson, SE Alexander, D Fludra, A Gopalswamy, N Hoeksema, JT Lecinski, A Strachan, L TI Synoptic Sun during the first Whole Sun Month Campaign: August 10 to September 8, 1996 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ULTRAVIOLET CORONAGRAPH SPECTROMETER; SOLAR; SOHO; TELESCOPE; MISSION; HOLE AB A large number of synoptic maps from a variety of instruments are used to show the general morphology of the Sun at the time of the First Whole Sun Month Campaign. The campaign was conducted from August 10 to September 8, 1996. The synoptic maps cover the period from Carrington rotation 1912/253 degrees to Carrington rotation 1913/45 degrees. The synoptic maps encompass both on-disk data and limb data from several heights in the solar atmosphere. The maps are used to illustrate which wavelengths and data sets show particular features, such as active regions and coronal holes. Of particular interest is the equatorial coronal hole known as the "elephant's trunk," which is clearly evident in the synoptic maps of on-disk data. The elephant's trunk is similar in appearance to the Shylab-era, "Boot of Italy," equatorial coronal hole. The general appearance of the limb maps is explained as well. The limb maps also show evidence for equatorial coronal holes. C1 Univ Birmingham, Sch Phys & Astron, Birmingham, W Midlands, England. Catholic Univ Amer, Washington, DC 20064 USA. Lockheed Martin Solar & Astrophys Lab, Palo Alto, CA USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Stanford Univ, Hansen Expt Phys Lab, Stanford, CA 94305 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Biesecker, DA (reprint author), NASA, Goddard Space Flight Ctr, Space Applicat Corp, Code 682-3, Greenbelt, MD 20771 USA. RI Gibson, Sarah/A-9189-2011; Gopalswamy, Nat/D-3659-2012; Thompson, Barbara/C-9429-2012 NR 21 TC 12 Z9 12 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 1999 VL 104 IS A5 BP 9679 EP 9689 DI 10.1029/1998JA900056 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BQ UT WOS:000080058600002 ER PT J AU Panasyuk, AV AF Panasyuk, AV TI Three-dimensional reconstruction of UV emissivities in the solar corona using Ultraviolet Coronagraph Spectrometer data from the Whole Sun Month SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article AB UV coronal intensity data collected by the Ultraviolet Coronagraph Spectrometer on SOHO in a daily synoptic program during: the Whole Sun Month are used to reconstruct the three-dimensional distribution of emissivities in the solar corona for H I Ly alpha and the O VI doublet at 1032 and 1037 Angstrom We discuss the specifics that complicate a tomographic reconstruction of the solar corona and estimate the uncertainties introduced in the reconstruction by them. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Panasyuk, AV (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS-50, Cambridge, MA 02138 USA. NR 6 TC 20 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 1999 VL 104 IS A5 BP 9721 EP 9726 DI 10.1029/1998JA900118 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BQ UT WOS:000080058600006 ER PT J AU Warren, HP Hassler, DM AF Warren, HP Hassler, DM TI The density structure of a solar polar coronal hole SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WAVE COLLISION STRENGTHS; LINE RATIOS; OSCILLATOR-STRENGTHS; ION TEMPERATURES; SUMER TELESCOPE; EMISSION-LINES; SI-III; WIND; SOHO; 8-LESS-THAN-OR-EQUAL-TO-Z-LESS-THAN-OR-EQUAL-TO-92 AB Electron densities derived from Si III, Ne VII, Mg VIII, Si VIII, and Mg IX line ratios observed above the limb of a polar coronal hole with the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on the Solar and Heliospheric Observatory (SoHO) are presented. The electron densities are consistent with a constant pressure of 1.6 x 10(14) cm(-3) K (log P-e = 14.2). C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. SW Res Inst, Boulder, CO 80302 USA. RP Warren, HP (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS 58, Cambridge, MA 02138 USA. NR 38 TC 10 Z9 10 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 1999 VL 104 IS A5 BP 9781 EP 9789 DI 10.1029/1998JA900079 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BQ UT WOS:000080058600011 ER PT J AU Dobrzycka, D Cranmer, SR Panasyuk, AV Strachan, L Kohl, JL AF Dobrzycka, D Cranmer, SR Panasyuk, AV Strachan, L Kohl, JL TI Study of the latitudinal dependence of H I Lyman alpha and O VI emission in the solar corona: Evidence for the superradial geometry of the outflow in the polar coronal holes SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID VELOCITY DISTRIBUTIONS; SPECTROMETER; WIND; EVOLUTION; UVCS/SOHO; ORIGIN AB We study the latitudinal distribution of the H I Lyman alpha and O VI (103.2 nm and 103.7 nm) line emission during the period of the Whole Sun Month campaign (August 10 to September 8, 1996) when the Sun was close to the minimum of its activity. The H I Lyman ct and O VI line intensities appeared to be almost constant with latitude within the polar coronal holes and have abrupt increases toward the streamer region. We found that both north and south polar coronal holes had similar line intensities and line-of-sight velocities, as well as kinetic temperatures of H-0 and O5+. Th, dependence of these parameters on latitude and radius is provided. We derived boundaries of the polar coronal holes based on the H I Lyman ct and O VI line intensity distributions for several days during the Whole Sun Month campaign. We found that the polar coronal hole boundaries clearly have a superradial geometry with diverging factor f(max) ranging from 6.0 to 7.5, and they are consistent with boundaries previously derived from the electron density distributions. We also found that, in general, they are not symmetric with respect to the heliographic poles, and their size and geometry change over periods of days. The H I Lyman a, O VI (103.2 nm), and the O VI (103.7 nm) line intensities showed similar boundaries within the uncertainties of our data. We modeled the latitudinal distribution of the H I Lyman a and O VI(103.2 nm and 103.7 nm) line intensities in the south polar coronal hole on August 17, 1996, assuming the coronal plasma outflow along either purely radial or nonradial flux tubes. A comparison of model predictions with the observed distributions shows evidence that the outflow velocity vectors follow nonradial intensity pattern. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Copernicus Astron Ctr, Warsaw, Poland. RP Dobrzycka, D (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 35 TC 24 Z9 24 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 1999 VL 104 IS A5 BP 9791 EP 9799 DI 10.1029/1998JA900129 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BQ UT WOS:000080058600012 ER PT J AU Casalbuoni, S Del Zanna, L Habbal, SR Velli, M AF Casalbuoni, S Del Zanna, L Habbal, SR Velli, M TI Coronal plumes and the expansion of pressure-balanced structures in the fast solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HELIOSPHERIC MAGNETIC-FIELD; ULYSSES OBSERVATIONS; FLOW PROPERTIES; POLAR PLUMES; HOLE; TEMPERATURE; MODEL; SOHO; ACCELERATION; INSTRUMENT AB The expansion of a coronal hole filled with a discrete number of higher-density filaments (plumes) in overall pressure balance with the ambient medium is described within the thin flux tube approximation. The resulting solar wind model extends the results of Parker [1964] and Velli et al. [1994] to nonisothermal temperature profiles and includes a flux of Alfven waves propagating both inside and outside the structures. Remote sensing and solar wind in situ observations are used to constrain the parameter range of our study. Close to the Sun, the precise plasma parameters are fundamental in determining the relative position of the critical points, which are found by means of an iterative procedure because the flows from the two regions are coupled. At greater distances the filling factor of the higher-density regions may vary largely, and streams which are either faster or slower than the wind arising from the ambient hole may result, depending on the temperature differences and on the flux of Alfven waves assumed in the two regions. Velocity differences of the order of similar to 50 km s(-1) such as those found in microstreams in the high-speed solar wind, might be thus easily explained by reasonable fluctuation amplitudes at the Sun, although the natural candidates for plumes at large heliocentric distances are more likely to be the so-called pressure-balanced structures. C1 Univ Florence, Dipartimento Astron & Sci Spazio, I-50125 Florence, Italy. Int Space Sci Inst, Bern, Switzerland. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Casalbuoni, S (reprint author), Univ Bern, Inst Phys, Bern, Switzerland. RI Del Zanna, Luca/N-5598-2015 OI Del Zanna, Luca/0000-0001-5200-882X NR 52 TC 30 Z9 30 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 1999 VL 104 IS A5 BP 9947 EP 9961 DI 10.1029/1999JA900047 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BQ UT WOS:000080058600025 ER PT J AU Olsen, EL Leer, E AF Olsen, EL Leer, E TI A study of solar wind acceleration based on gyrotropic transport equations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ANISOTROPIC PROTON TEMPERATURE; 2-FLUID MODEL; VELOCITY DISTRIBUTIONS; 8-MOMENT APPROXIMATION; NEUTRAL HYDROGEN; ALFVEN WAVES; CORONAL HOLE; PLASMAS; REGION AB The gyrotropic transport equations are used to describe an electron-proton solar wind from the 500,000 K level in the upper transition region and out to 30 solar radii. These equations allow for different temperatures parallel and perpendicular to the magnetic field, as well as transport of parallel and perpendicular thermal energy along the field. We find that in models with significant coronal proton heating, the electron temperature is much lower than the proton temperature. The electron gas is collision dominated, the thermal anisotropy is small, and the heat flux is close to a "classical" heat flux. The proton gas is collision dominated in the upper transition region, but the temperature increases rapidly in the inner corona, and the protons become collisionless close to the Sun. The proton heat flux is proportional to the temperature gradient very close to the Sun, but in the extended corona it deviates substantially from a classical heat flux. In models where the proton heating is in the direction perpendicular to the magnetic field, a large perpendicular temperature is produced locally, but the perpendicular thermal motion couples into parallel thermal motion, and the parallel temperature increases outward from the Sun. We obtain a maximum parallel temperature that is comparable to the maximum perpendicular temperature. This result seems to hold for all models where the energy flux necessary to drive high-speed wind is deposited in the corona as heat. The result is not in agreement with UVCS/SOHO observations of the 1216 Angstrom Ly-alpha line in large coronal holes. These observations are consistent with a much larger random proton motion perpendicular to the magnetic field than parallel to the field. Such anisotropies can be obtained in models of high-speed solar wind if we allow for a significant fraction of the energy flux from the Sun to be in the form of low-frequency, transverse waves. These waves accelerate the solar wind without heating the corona, and they contribute to the line broadening in the direction perpendicular to the magnetic field. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. RP Olsen, EL (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS 50, Cambridge, MA 02138 USA. NR 36 TC 41 Z9 41 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 1999 VL 104 IS A5 BP 9963 EP 9973 DI 10.1029/1998JA900152 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BQ UT WOS:000080058600026 ER PT J AU Sallum, MAM Wilkerson, RC Forattini, OP AF Sallum, MAM Wilkerson, RC Forattini, OP TI Taxonomic study of species formerly identified as Anopheles mediopunctatus and resurrection of An. costai (Diptera : Culicidae) SO JOURNAL OF MEDICAL ENTOMOLOGY LA English DT Article DE Anopheles; mediopunctatus; costai; Arribalzagia; redescription; taxonomy ID BRAZIL; RONDONIA; MALARIA; MOSQUITOS; STATE AB Anopheles (Anopheles) mediopunctatus (Lutz) and Anopheles (Anopheles) costal Fonseca & Ramos are redescribed with illustrations of the male genitalia and larval and pupal stages. The pupa of An, costai has paired lateral projections on the wing case, a feature also known in members of the Umbrosus Group from Southeast Asia. An. costal is resurrected from the synonymy of An. mediopunctatus based on features of the male genitalia, larva, and pupa, and An. bonneortum. Fonseca & Ramos (emended from bonnei) is considered to be a new synonym of An. costai. It is noted that the author of An. mediopunctatus is Lutz, not Theobald, as cited in most literature references. C1 Univ Sao Paulo, NUPTEM, Fac Saude Publ, Dept Epidemiol, BR-01246904 Sao Paulo, Brazil. RP Sallum, MAM (reprint author), Smithsonian Inst, Walter Reed Biosystemat Unit, MRC 534, Museum Support Ctr, Washington, DC 20560 USA. RI Sallum, Maria/B-8537-2012 NR 81 TC 17 Z9 19 U1 0 U2 0 PU ENTOMOL SOC AMER PI LANHAM PA 9301 ANNAPOLIS RD, LANHAM, MD 20706 USA SN 0022-2585 J9 J MED ENTOMOL JI J. Med. Entomol. PD MAY PY 1999 VL 36 IS 3 BP 282 EP 300 PG 19 WC Entomology; Veterinary Sciences SC Entomology; Veterinary Sciences GA 203AZ UT WOS:000080686000013 PM 10337098 ER PT J AU Wilkerson, RC Sallum, MAM AF Wilkerson, RC Sallum, MAM TI Anopheles (Anopheles) forattinii: a new species in Series Arribalzagia (Diptera : Culicidae) SO JOURNAL OF MEDICAL ENTOMOLOGY LA English DT Article DE Anopheles; forattinii; new species; Arribalzagia; description; taxonomy ID RONDONIA; BRAZIL; MOSQUITOS; MALARIA AB Anopheles (Anopheles) forattinii new species, a member of the Series Arribalzagia, is described with illustrations of the larval and pupal stages, and male and female genitalia. It is contrasted with 2 similar species, An. (Anopheles) costal Fonseca & Ramos and An. (Anopheles) mediopunctatus (Lutz). This species, and An. costal, occur over much of South America where both have been misidentified as An. mediopunctatus, a species presently only known from southeastern Brazil. C1 Walter Reed Army Med Ctr, Walter Reed Army Inst Res, Dept Entomol, Washington, DC 20307 USA. RP Wilkerson, RC (reprint author), Smithsonian Inst, Museum Support Ctr, Walter Reed Biosystemat Unit, MRC 534, Washington, DC 20560 USA. RI Sallum, Maria/B-8537-2012 NR 19 TC 18 Z9 20 U1 0 U2 0 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-2585 EI 1938-2928 J9 J MED ENTOMOL JI J. Med. Entomol. PD MAY PY 1999 VL 36 IS 3 BP 345 EP 354 PG 10 WC Entomology; Veterinary Sciences SC Entomology; Veterinary Sciences GA 203AZ UT WOS:000080686000021 PM 10337106 ER PT J AU Crouch, TD AF Crouch, TD TI Jannus: An American flier SO JOURNAL OF SOUTHERN HISTORY LA English DT Book Review C1 Smithsonian Inst, Natl Air & Space Museum, Washington, DC 20560 USA. RP Crouch, TD (reprint author), Smithsonian Inst, Natl Air & Space Museum, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SOUTHERN HISTORICAL ASSOC PI ATHENS PA UNIV GEORGIA, HISTORY DEPT, ATHENS, GA 30602 USA SN 0022-4642 J9 J SOUTHERN HIST JI J. South. Hist. PD MAY PY 1999 VL 65 IS 2 BP 433 EP 434 DI 10.2307/2587417 PG 2 WC History SC History GA 194QR UT WOS:000080205500056 ER PT J AU Ruiz, GM Fofonoff, P Hines, AH Grosholz, ED AF Ruiz, GM Fofonoff, P Hines, AH Grosholz, ED TI Non-indigenous species as stressors in estuarine and marine communities: Assessing invasion impacts and interactions SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Symposium on the Effects of Multiple Stressors on Freshwater and Marine Ecosystems at the Annual Meeting of the American-Society-of-Limnology-and-Oceanography CY FEB, 1997 CL SANTA FE, NM SP Amer Soc Limnol & Oceanog ID SAN-FRANCISCO BAY; AMERICAN BLACK DUCKS; CARP CYPRINUS-CARPIO; NATIVE MUD SNAILS; CHESAPEAKE-BAY; POTOMAC RIVER; CRASSOSTREA-VIRGINICA; PERKINSUS-MARINUS; EASTERN OYSTER; PHRAGMITES-AUSTRALIS AB Invasions by non-indigenous species (NIS) are recognized as important stressors of many communities throughout the world. Here, we evaluated available data on the role of MS in marine and estuarine communities and their interactions with other anthropogenic stressors, using an intensive analysis of the Chesapeake Bay region as a case study. First, we reviewed the reported ecological impacts of 196 species that occur in tidal waters of the bay, including species that are known invaders as well as some that are cryptogenic (i.e., of uncertain origin). Second, we compared the impacts reported in and out of the bay region for the same 54 species of plants and fish from this group that regularly occur in the region's tidal waters. Third, we assessed the evidence for interaction in the distribution or performance of these 54 plant and fish species within the bay and other stressors. Of the 196 known and possible NIS, 39 (20%) were thought to have some significant impact on a resident population, community, habitat, or process within the bay region. However, quantitative data on impacts were found for only 12 of the 39, representing 31% of this group and 6% of all 196 species surveyed. The patterns of reported impacts in the bay for plants and fish were nearly identical: 29% were reported to have significant impacts, but quantitative impact data existed for only 7% (4/54) of these species. In contrast, 74% of the same species were reported to have significant impacts outside of the bay, and some quantitative impact data were found for 44% (24/54) of them. Although it appears that 20% of the plant and fish species in our analysis may have significant impacts in the bay region based upon impacts measured elsewhere, we suggest that studies outside the region cannot reliably predict such impacts. We surmise that quantitative impact measures for individual bays or estuaries generally exist for <5% of the NIS present, and many of these measures are not particularly informative. Despite the increasing knowledge of marine invasions at many sites, it is evident that we understand little about the full extent and variety of the impacts they create-singly and cumulatively. Given the multiple anthropogenic stressors that overlap with NIS in estuaries, we predict NIS-stressor interactions play an important role in the pattern and impact of invasions. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Univ Calif Davis, Dept Environm Sci & Policy, Davis, CA 95616 USA. RP Ruiz, GM (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. OI Ruiz, Gregory/0000-0003-2499-441X NR 291 TC 212 Z9 221 U1 5 U2 52 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0024-3590 EI 1939-5590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD MAY PY 1999 VL 44 IS 3 BP 950 EP 972 PN 2 PG 23 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 196UU UT WOS:000080326600019 ER PT J AU Houston, RM Huber, BT Spero, HJ AF Houston, RM Huber, BT Spero, HJ TI Size-related isotopic trends in some Maastrichtian planktic foraminifera: methodological comparisons, intraspecific variability, and evidence for photosymbiosis SO MARINE MICROPALEONTOLOGY LA English DT Article DE planktic foraminifera; ontogeny; stable isotopes; Maastrichtian; heterohelicid; photosymbiosis ID GLOBIGERINOIDES-SACCULIFER; OXYGEN; CARBON; PALEOTEMPERATURES; PHOTOSYNTHESIS; DELTA-O-18; ATLANTIC; SIGNALS AB The serial test dissection and sieve fraction methods for determining the pattern of size-related change in oxygen and carbon isotopic ratios are compared using four Late Cretaceous planktic foraminifer species (Racemiguembelina fructicosa, Planoglobulina acervulinoides, Planoglobulina multicamerata, and Pseudoguembelina palpebra) from a subtropical site in the North Atlantic (DSDP Hole 390A). Despite the extra labor required, we identify several clear advantages of the dissection method, including: (1) it provides a means of obtaining size-dependent changes in isotopic signatures that are unequivocally ontogenetic, whereas isotopic variation observed from sieve-separated size fractions could be ontogenetic or ecotypic; (2) the taxonomic identity of smaller sized specimens using the dissection method is unequivocal, whereas species identification is increasingly ambiguous in smaller size fractions using the sieve method; (3) it reveals a greater total range and a greater complexity in the pattern of ontogenetic change in stable isotopic values, whereas the sieve method averages the isotopic signal across the entire ontogenetic range preserved within the whole tests that are used. Our results from serial dissections demonstrate that among the species analyzed, R. fructicosa and P, acervulinoides yield relatively negative adult delta(18)O values, a large size-related change in delta(13)C values (1.32 and 2.05 parts per thousand, respectively), and virtually no correlation between size-related delta(13)C and delta(18)O values. On this basis we suggest that these were photosymbiotic species that inhabited relatively shallow surface waters. Evidence for photosymbiosis is not as compelling for P. palpebra, as this species yields a 1.06 parts per thousand shift in delta(13)C and relatively negative delta(18)O values in adult chambers, but much stronger correlation between size-related delta(13)C and delta(18)O values (r(2) = 0.40) than in R. fructicosa and P. acervulinoides. Planoglobulina multicamerata yields the most positive adult delta(18)O values of the species studied, a strong covariance between size-related delta(13)C and delta(18)O values (r(2) = 0.77), and a 0.97 parts per thousand shift in delta(13)C composition during ontogeny. We conclude that this species lacked photosymbionts and migrated to a deeper surface water paleohabitat as it increased in size. Single specimen analyses of tightly constrained size fractions reveal a high degree of intraspecific variation. delta(13)C and delta(18)O values vary by up to 0.70 and 0.28 parts per thousand in R. fructicosa, 1.41 and 0.80 parts per thousand in P. acervulinoides, 0.66 and 0.82 parts per thousand in P. palpebra, and 0.18 and 0.33 parts per thousand in P. multicamerata, respectively. Such a range of isotopic variation has been observed in modern day planktic foraminifer assemblages, and likely results from growth of individuals during different phases of the seasonal cycle and/or the kinetic effect of intraspecific variation in shell calcification rates. As suggested by other investigators, large sample sizes should be analyzed to provide the most reliable correlation of stable isotopic stratigraphic records. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Smithsonian Inst, Dept Paleobiol, Washington, DC 20560 USA. Univ Calif Davis, Dept Geol, Davis, CA 95616 USA. RP Huber, BT (reprint author), Smithsonian Inst, Dept Paleobiol, NHB-E206,Mail Stop 121, Washington, DC 20560 USA. OI Spero, Howard/0000-0001-5465-8607 NR 27 TC 25 Z9 26 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD MAY PY 1999 VL 36 IS 4 BP 169 EP 188 DI 10.1016/S0377-8398(99)00007-9 PG 20 WC Paleontology SC Paleontology GA 191RB UT WOS:000080034400001 ER PT J AU Wood, JA AF Wood, JA TI 1998 Leonard Medal citation for Stuart Ross Taylor - 1998 July 27, Dublin, Ireland SO METEORITICS & PLANETARY SCIENCE LA English DT Biographical-Item C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Wood, JA (reprint author), Smithsonian Astrophys Observ, 60 Garden St, Cambridge, MA 02138 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD MAY PY 1999 VL 34 IS 3 BP 315 EP 316 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 201AL UT WOS:000080572400005 ER PT J AU McRae, SB Amos, W AF McRae, SB Amos, W TI Characterization of hypervariable microsatellites in the cooperatively breeding white-browed sparrow weaver Plocepasser mahali SO MOLECULAR ECOLOGY LA English DT Article DE cooperative breeding; microsatellite; PCR; Ploceidae; Plocepasser mahali; primers; weaverbird; white-browed sparrow weaver ID DNA C1 Dept Zool, Cambridge CB2 3EJ, England. RP McRae, SB (reprint author), Smithsonian Trop Res Inst, Unit 0948,APO AA, Miami, FL 34002 USA. NR 7 TC 14 Z9 14 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD MAY PY 1999 VL 8 IS 5 BP 903 EP 904 PG 2 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 207TY UT WOS:000080952900025 PM 10368974 ER PT J AU Montes, D Saar, SH Collier Cameron, A Unruh, YC AF Montes, D Saar, SH Collier Cameron, A Unruh, YC TI Optical and ultraviolet observations of a strong flare in the young, single K2 dwarf LQ Hya SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE line : profiles; stars : activity; stars : chromospheres; stars : flare; stars : individual : LQ Hya; stars : late-type ID CHROMOSPHERICALLY ACTIVE BINARIES; H-ALPHA EMISSION; CA-II-H; RS CANUM VENATICORUM; YZ-CANIS-MINORIS; X-RAY FLARE; SOLAR-FLARES; UV CETI; ROTATIONAL MODULATION; CLOSE BINARIES AB We present high-resolution optical echelle spectra and IUE observations during a strong flare on 1993 December 22 in the very active, young, rapidly rotating, single K2 dwarf LQ Hya. The initial impulsive phase of the flare, which started sometime between 2:42 UT and 4:07 UT, was characterized by strong optical continuum enhancement and blueshifted emission lines with broad wings. The optical chromospheric lines reached their maximum intensity at approximate to 5:31 UT, by which time the blueshift vanished and the optical continuum enhancement had sharply decreased. Thereafter, the line emission slowly decreased and the lines redshift in a gradual phase that lasted at least two more hours, The Mg II lines behaved similarly. Quiescent C IV flux levels were not recovered until 21 h later, though a data gap and a possible second flare make the interpretation uncertain. In addition to the typically flare-enhanced emission lines (e.g., H alpha and H beta), we observe He I D(3) going into emission, plus excess emission (after subtraction of the quiescent spectrum) in other He I and several strong neutral metal lines (e.g., Mg I b). Flare enhancement of the far-ultraviolet continuum generally agrees with an Si I recombination model. We estimate the total flare energy, and discuss the broad components, asymmetries and Doppler shifts seen in some of the emission lines. C1 Univ Complutense Madrid, Fac Fis, Dept Astrofis, E-28040 Madrid, Spain. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9SS, Fife, Scotland. Univ Vienna, Inst Astron, A-1180 Vienna, Austria. RP Montes, D (reprint author), Univ Complutense Madrid, Fac Fis, Dept Astrofis, E-28040 Madrid, Spain. EM dmg@astrax.fis.ucm.es RI Montes, David/B-9329-2014 OI Montes, David/0000-0002-7779-238X NR 81 TC 38 Z9 38 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 1 PY 1999 VL 305 IS 1 BP 45 EP 60 DI 10.1046/j.1365-8711.1999.02373.x PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 195UN UT WOS:000080270700014 ER PT J AU Menou, K Hameury, JM Stehle, R AF Menou, K Hameury, JM Stehle, R TI Structure and properties of transition fronts in accretion discs SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; instabilities; binaries : close; novae, cataclysmic variables ID DWARF NOVA OUTBURSTS; LONG-TERM BEHAVIOR; X-RAY BINARIES; LIMIT-CYCLE; CATACLYSMIC VARIABLES; INSTABILITY MODEL; COOLING FRONTS; BLACK-HOLES; SS-CYGNI; DISKS AB We use high-resolution time-dependent numerical simulations of accretion discs around white dwarfs to study the structure and properties of transition fronts in the context of the thermal-viscous disc instability model. The thermal structure of cooling and heating fronts is dominated by radiative cooling and viscous heating, respectively, except in a very narrow precursor region in heating fronts where advection and radial transport of energy dominate, Cooling fronts are much broader than heating fronts, but the widths of both types of fronts scale with the local vertical scaleheight of the disc. We confirm that during a fair fraction of the propagation time of a cooling front, the structure of the inner disc is close to self-similar. The speed of heating fronts is similar to a few km s(-1), while the speed of cooling fronts is similar to a fraction of a km s(-1). We show that direct measurements of the speed of transition fronts probably cannot discriminate between various prescriptions proposed for the viscosity parameter a. A natural prediction of the disc instability model is that fronts decelerate as they propagate in the disc, independent of the prescription for alpha. Observation of this effect would confirm that dwarf nova outbursts are driven by the thermal-viscous instability. Most of our results also apply to low mass X-ray binaries in which the accreting object is a neutron star or a black hole. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Observ Paris, UPR 176 CNRS, Dept Astrophys Relativiste & Cosmol, Sect Meudon, F-92195 Meudon, France. Observ Strasbourg, UMR 7550 CNRS, F-67000 Strasbourg, France. Univ Leicester, Astron Grp, Leicester LE1 7RH, Leics, England. RP Menou, K (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 34 TC 30 Z9 30 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 1 PY 1999 VL 305 IS 1 BP 79 EP 89 DI 10.1046/j.1365-8711.1999.02396.x PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 195UN UT WOS:000080270700016 ER PT J AU Di Matteo, T Esin, A Fabian, AC Narayan, R AF Di Matteo, T Esin, A Fabian, AC Narayan, R TI On the origin of the hard X-ray background SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Letter DE accretion, accretion discs; galaxies : active; galaxies : nuclei; X-rays : galaxies; X-rays : general ID ADVECTION-DOMINATED ACCRETION; ROSAT DEEP SURVEY; ION-SUPPORTED TORI; BLACK-HOLE; ASCA OBSERVATIONS; FAINT GALAXIES; LOCKMAN FIELD; CYGNUS X-1; MODEL; SPECTRA AB Several models for the hard X-ray background (XRB) suggest that it is a result of the emission from heavily obscured AGN. Recent studies have revealed the presence of a new population of hard X-ray sources that must contribute significantly to the XRB. However, whether the majority of these sources are obscured AGN or some other type of object at present remains unclear, Here, we further examine the possibility that a significant fraction of the XRB comes from a population of galaxies undergoing advection-dominated accretion in the high-(m) over dot regime and thus produce intrinsically hard spectra. When the accretion rate is close to (m) over dot (crit) above which an advection-dominated accretion flow (ADAF) no longer exists, the major or contribution to X-ray emission is from inverse Compton scattering of the soft seed photons produced by cyclo-synchrotron radiation. In this regime, the resulting ADAF spectra are relatively hard with a fairly constant X-ray spectral index alpha similar to 0.2-0.4 and a spectral cut-off at similar to 200 keV. We show that the integrated emission from such sources can provide a good fit to the hard (> 2keV) X-ray background, provided that the spectrum is dominated by the contribution from objects located at redshifts z similar to 2-3. The model requires most of the contribution to the XRB to be resulting from objects accreting at (m) over dot (crit). C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Pasadena, CA 91125 USA. RI Di Matteo, Tiziana/O-4762-2014 OI Di Matteo, Tiziana/0000-0002-6462-5734 NR 40 TC 12 Z9 12 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 1 PY 1999 VL 305 IS 1 BP L1 EP L5 DI 10.1046/j.1365-8711.1999.02541.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 195UN UT WOS:000080270700001 ER PT J AU Weil, SE AF Weil, SE TI Making the nonprofit sector in the United States: A reader SO MUSEUM NEWS LA English DT Book Review C1 Smithsonian Inst, Ctr Museum Studies, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC MUSEUMS PI WASHINGTON PA 1575 EYE ST, NW, STE 400, WASHINGTON, DC 20005 USA SN 0027-4089 J9 MUSEUM NEWS JI Mus. News PD MAY-JUN PY 1999 VL 78 IS 3 BP 27 EP + PG 0 WC Art SC Art GA 188QZ UT WOS:000079861000010 ER PT J AU Said, T AF Said, T TI America's promise and a place for museums (Community service and safe-places programming lead a trend in museum volunteerism) SO MUSEUM NEWS LA English DT Article C1 Smithsonian Inst, Off Educ, Washington, DC 20560 USA. RP Said, T (reprint author), Smithsonian Inst, Off Educ, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC MUSEUMS PI WASHINGTON PA 1575 EYE ST, NW, STE 400, WASHINGTON, DC 20005 USA SN 0027-4089 J9 MUSEUM NEWS JI Mus. News PD MAY-JUN PY 1999 VL 78 IS 3 BP 40 EP + PG 0 WC Art SC Art GA 188QZ UT WOS:000079861000012 ER PT J AU Tang, EPY Vincent, WF AF Tang, EPY Vincent, WF TI Strategies of thermal adaptation by high-latitude cyanobacteria SO NEW PHYTOLOGIST LA English DT Article DE Antarctic; Arctic; cyanobacteria; carbon partitioning; photosynthesis; pigment ID LOW-TEMPERATURE MIMICS; MARINE-PHYTOPLANKTON; ELECTRON-TRANSPORT; CARBON METABOLISM; PHOTOSYSTEM-II; LIGHT; PHOTOSYNTHESIS; GROWTH; CHLOROPHYLL; ICE AB Although mat-forming cyanobacteria dominate many freshwater ecosystems in the Arctic and Antarctic, their optimal temperature for growth (T-opt) is usually much higher than the temperature range of their native habitat. The present study compared the temperature dependence of growth, pigment composition and absorbance, photosynthesis and photosynthate partitioning for two strains of cyanobacteria with contrasting T-opt values; Phormidium subfuscum, isolated from McMurdo Ice Shelf, Antarctica, and Phormidium tenue, collected from the Kuparuk River in the tundra region of northern Alaska. Phormidium subfuscum grew between 5 and 20 degrees C with a T-opt of 15 degrees C whereas P. tenue showed detectable growth from 10 to 40 degrees C and a T-opt of 30 degrees C. Light utilization efficiency, photosynthetic capacity and the irradiance at the onset of light saturation increased with increasing temperature up to T-opt in both strains. The cellular concentrations of chlorophyll a (Chl a) and carotenoid (CAR) and the in vivo absorbance maxima for Chi a, CAR, C-phycocyanin and allophycocyanin changed little for P. subfuscum but all these variables increased across the temperature range up to T-opt for P. tenue. Neither P. subfuscum nor P. tenue showed changes in relative carbon allocation with varying temperature, suggesting that gross biochemical alterations are not a characteristic of temperature acclimation in these cyanobacteria. We conclude that the eurythermal cyanobacterium P. tenue optimizes growth over a wide range of temperatures by adjusting its light-capturing as well as carbon fixation characteristics, whereas stenothermal P. subfuscum relies on changes in carbon fixation without concomitant shifts in pigment content. C1 Univ Laval, Dept Biol, St Foy, PQ G1K 7P4, Canada. Univ Laval, Ctr Etud Nord, St Foy, PQ G1K 7P4, Canada. RP Tang, EPY (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. RI Vincent, Warwick/C-9522-2009; OI Vincent, Warwick/0000-0001-9055-1938 NR 51 TC 24 Z9 27 U1 1 U2 14 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0028-646X J9 NEW PHYTOL JI New Phytol. PD MAY PY 1999 VL 142 IS 2 BP 315 EP 323 DI 10.1046/j.1469-8137.1999.00385.x PG 9 WC Plant Sciences SC Plant Sciences GA 208PT UT WOS:000081001100012 ER PT J AU Dalling, JW Harms, KE AF Dalling, JW Harms, KE TI Damage tolerance and cotyledonary resource use in the tropical tree Gustavia superba SO OIKOS LA English DT Article ID QUERCUS-ROBUR SEEDLINGS; RAIN-FOREST; SEED SIZE; ESTABLISHMENT CONDITIONS; LIGHT REQUIREMENTS; PHYSICAL DAMAGE; WOODY-PLANTS; LECYTHIDACEAE; REGENERATION; DISPERSAL AB Explanations for the extremely large seed size of some tropical forest plants are currently lacking. In this study we examine cotyledonary resource use of the tropical tree Gustavia superba, and test whether tolerance to damage of either seeds or establishing seedlings might be an important function leading to, or maintaining, its large (> 5 g) seed reserves. We found that seeds of Gustavia were both tolerant of insect infestation and were also capable of successful germination after removal of half of their cotyledonary reserves. Simulated complete above-ground herbivory resulted in repeated resprouting (up to 8 times). Resprout shoots were constructed of a small, but fixed proportion of remaining cotyledonary mass regardless of seed size. In the absence of damage, cotyledon reserves were used for onward seedling growth; however, conversion of cotyledon resources was slow, lasting several months. Given high rates of damage to Gustavia seeds and seedlings in the field, and the apparent use of cotyledonary reserves to tolerate or recover from it in growing house experiments, we conclude that cotyledonary seed size and morphology in this species is adaptive in surviving pre- and early post-germination hazards. C1 Smithsonian Trop Res Inst, Balboa, Panama. RP Dalling, JW (reprint author), Smithsonian Trop Res Inst, Apartado 2072, Balboa, Panama. EM dallingj@bci.si.edi NR 41 TC 41 Z9 42 U1 3 U2 11 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0030-1299 J9 OIKOS JI Oikos PD MAY PY 1999 VL 85 IS 2 BP 257 EP 264 DI 10.2307/3546491 PG 8 WC Ecology SC Environmental Sciences & Ecology GA 205VN UT WOS:000080841400008 ER PT J AU Newburg, DS Warren, CD Chaturvedi, P Newburg, A Oftedal, OT Ye, S Tilden, CD AF Newburg, DS Warren, CD Chaturvedi, P Newburg, A Oftedal, OT Ye, S Tilden, CD TI Milk oligosaccharidees across species SO PEDIATRIC RESEARCH LA English DT Meeting Abstract C1 Shriver Ctr Mental Retardat, Waltham, MA 02254 USA. Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. Boston Univ, Med Ctr, Boston, MA USA. Univ Kansas, Dept Anthropol, Lawrence, KS 66045 USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU INT PEDIATRIC RESEARCH FOUNDATION, INC PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 USA SN 0031-3998 J9 PEDIATR RES JI Pediatr. Res. PD MAY PY 1999 VL 45 IS 5 MA 16c BP 745 EP 745 PN 1 PG 1 WC Pediatrics SC Pediatrics GA 192PC UT WOS:000080086700043 ER PT J AU Jonsell, S Wallenius, J Froelich, P AF Jonsell, S Wallenius, J Froelich, P TI Influence of pp pi ions on pion absorption in H-2 SO PHYSICAL REVIEW A LA English DT Article ID KINETIC-ENERGY DISTRIBUTION; PRECISION-MEASUREMENT; DT-MU; MOLECULES; HYDROGEN; ATOMS; DYNAMICS; CASCADE; FUSION AB The existence of three-body resonances in the molecular ion pp pi has been shown by means of a variational calculation in Jacobi coordinates. The relativistic and strong-force corrections to the Coulombic binding energies and the decay widths of the resonances have been calculated. We consider two mechanisms that supply the p pi atom with large kinetic energies before the moment of pion absorption by the proton, with significant impact on the interpretation of experiments measuring the mass difference m(pi)- (-)m(pi 0) from pion absorption in pionic atoms. These mechanisms are (a) the formation and subsequent Coulomb decay of the metastable pp pi states and (b) pion absorption from the molecular pp pi state, giving, respectively, a discrete or a continuous distribution of kinetic energies of the resulting p pi atoms. [S1050-2937(99)05005 1]. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Uppsala Univ, Dept Quantum Chem, S-75120 Uppsala, Sweden. Royal Inst Technol, Dept Nucl & Reactor Phys, S-10044 Stockholm, Sweden. RP Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. RI Jonsell, Svante/J-2251-2016 OI Jonsell, Svante/0000-0003-4969-1714 NR 29 TC 35 Z9 35 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1999 VL 59 IS 5 BP 3440 EP 3453 DI 10.1103/PhysRevA.59.3440 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 197UB UT WOS:000080383100043 ER PT J AU Segev, B Wells, JC AF Segev, B Wells, JC TI Exact Z(2) scaling of pair production in the high-energy limit of heavy-ion collisions SO PHYSICAL REVIEW C LA English DT Article ID ELECTROMAGNETIC-FIELDS; IONIZATION AB The two-center Dirac equation for an electron in the external electromagnetic field of two colliding heavy ions in the limit in which the ions are moving at the speed of light is exactly solved off the light fronts, and nonperturbative amplitudes are obtained for free electron-positron pair production. We find the condition for the applicability of this solution for large but finite collision energy, and use it to explain recent experimental results. The observed scaling of positron yields as the square of the projectile and target charges is a result of a cancellation of a nonperturbative charge dependence and holds as well for large coupling. Other observables would be sensitive to nonperturbative phases. [S0556-2813(99)03505-0]. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel. Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. RP Segev, B (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. RI Wells, Jack/D-3675-2016 OI Wells, Jack/0000-0002-5083-3030 NR 14 TC 22 Z9 22 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAY PY 1999 VL 59 IS 5 BP 2753 EP 2756 DI 10.1103/PhysRevC.59.2753 PG 4 WC Physics, Nuclear SC Physics GA 197UC UT WOS:000080383200054 ER PT J AU Medvedev, MV AF Medvedev, MV TI Thermodynamics of photons in relativistic e(+)e(-) gamma plasmas SO PHYSICAL REVIEW E LA English DT Article AB Thermodynamic and spectral properties of a photon gas in e(+)e(-) gamma plasmas are studied. The effect of a finite effective mass of a photon, associated with the plasma frequency cutoff, is self-consistently included, in the ultrarelativistic plasmal the photon spectrum turns out to be universal with the temperature normalized plasma frequency cutoff as a fundamental constant independent of plasma parameters. Such a universality does not hold in the nonrelativistic plasma. [S1063-651X(99)50305-X]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Kurchatov Inst, RRC, Inst Nucl Fus, Moscow 123182, Russia. RP Medvedev, MV (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 6 TC 16 Z9 16 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD MAY PY 1999 VL 59 IS 5 BP R4766 EP R4768 DI 10.1103/PhysRevE.59.R4766 PN A PG 3 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 197TX UT WOS:000080382700016 PM 11969515 ER PT J AU Medvedev, MV AF Medvedev, MV TI Collisionless dissipative nonlinear Alfven waves: Nonlinear steepening, compressible turbulence, and particle trapping SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 40th Annual Meeting of the Division of Plasma Physics of the American-Physical-Society CY NOV 16-20, 1998 CL NEW ORLEANS, LOUISIANA SP Amer Phys Soc, Div Plasma Phys ID ROTATIONAL DISCONTINUITIES; HYDROMAGNETIC-WAVES; FLUID MODELS; BETA PLASMA; TRAINS; EVOLUTION; EQUATION AB The magnetic energy of nonlinear Alfven waves in compressible plasmas may be ponderomotively coupled only to ion-acoustic quasi-modes, which modulate the wave phase velocity and cause wave-front steepening. In the collisionless plasma with beta not equal 0, the dynamics of nonlinear Alfven wave is also affected by the resonant particle-wave interactions. Upon relatively rapid evolution (compared to the particle bounce time), the quasi-stationary wave structures, identical to the so-called (Alfvenic) Rotational Discontinuities, form, the emergence and dynamics of which has not been previously understood. Collisionless (Landau) dissipation of nonlinear Alfven waves is also a plausible and natural mechanism of the solar wind heating. Considering a strong, compressible, Alfvenic turbulence as an ensemble of randomly interacting Alfvenic discontinuities and nonlinear waves, it is shown that there exist two distinct phases of turbulence. What phase realizes depends on whether this collisionless damping is strong enough to provide adequate energy sink at all scales and, thus, to support a steady-state cascade of the wave energy. In long-time asymptotics, however, the particle distribution function is affected by the wave magnetic fields. In this regime of nonlinear Landau damping, resonant particles are trapped in the quasi-stationary Alfvenic discontinuities, giving rise to a formation of a plateau on the distribution function and quenching collisionless damping. Using the virial theorem for trapped particles, it is analytically demonstrated that their effect on the nonlinear dynamics of such discontinuities is nontrivial and forces a significant departure of the theory from the conventional paradigm. (C) 1999 American Institute of Physics. [S1070-664X(99)94305-7]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RRC Kurchatov Inst, Inst Nucl Fus, Moscow 123182, Russia. RP Medvedev, MV (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 24 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1999 VL 6 IS 5 BP 2191 EP 2197 DI 10.1063/1.873471 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 190ND UT WOS:000079969500064 ER PT J AU Golub, L Bookbinder, J DeLuca, E Karovska, M Warren, H Schrijver, CJ Shine, R Tarbell, T Title, A Wolfson, J Handy, B Kankelborg, C AF Golub, L Bookbinder, J DeLuca, E Karovska, M Warren, H Schrijver, CJ Shine, R Tarbell, T Title, A Wolfson, J Handy, B Kankelborg, C TI A new view of the solar corona from the transition region and coronal explorer (TRACE) SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 40th Annual Meeting of the Division of Plasma Physics of the American-Physical-Society CY NOV 16-20, 1998 CL NEW ORLEANS, LA SP Amer Phys Soc, Div Plasma Phys ID X-RAY-TELESCOPE; MAGNETIC RECONNECTION; HIGH-RESOLUTION; FLARE LOOPS; YOHKOH; PLASMA; MORPHOLOGY; EMISSION; DYNAMICS; MISSION AB The TRACE Observatory is the first solar-observing satellite in the National Aeronautics and Space Administration's (NASA) Small Explorer series. Launched April 2, 1998, it is providing views of the solar transition region and low corona with unprecedented spatial and temporal resolution. The corona is now seen to be highly filamented, and filled with flows and other dynamic processes. Structure is seen down to the resolution limit of the instrument, while variability and motions are observed at all spatial locations in the solar atmosphere, and on very short time scales. Flares and shock waves are observed, and the formation of long-lived coronal structures, with consequent implications for coronal heating models, has been seen. This overview describes the instrument and presents some preliminary results from the first six months of operation. (C) 1999 American Institute of Physics. [S1070-664X(99)91805-0]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Lockheed Martin Solar & Astrophys Lab, Palo Alto, CA 94304 USA. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. RP Golub, L (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI DeLuca, Edward/L-7534-2013; OI DeLuca, Edward/0000-0001-7416-2895; Golub, Leon/0000-0001-9638-3082 NR 46 TC 100 Z9 100 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1999 VL 6 IS 5 BP 2205 EP 2216 DI 10.1063/1.873473 PN 2 PG 12 WC Physics, Fluids & Plasmas SC Physics GA 190ND UT WOS:000079969500066 ER PT J AU Kepner, RL Wharton, RA Coats, DW AF Kepner, RL Wharton, RA Coats, DW TI Ciliated protozoa of two antarctic lakes: analysis by quantitative protargol staining and examination of artificial substrates SO POLAR BIOLOGY LA English DT Article ID HILLS EASTERN ANTARCTICA; ICE-COVERED LAKE; WATER-COLUMN; VICTORIA-LAND; SALINE LAKES; ALGAL MATS; DYNAMICS; FRYXELL; COMMUNITIES; PLANKTON AB Planktonic and artificial substrate-associated ciliates have been identified in two perennially ice-covered antarctic lakes of the McMurdo Dry Valleys. Abundances estimated by quantitative protargol staining ranged from <5 to 31690 2cells . l(-1), levels that are comparable to those previously obtained using other methods. Nineteen ciliate taxa were identified from these lakes, with the most frequently encountered genera being Plagiocampa, Askenasia, Monodinium, Sphaerophrya and Vorticella. The taxonomic findings compare favorably with those of previous investigators; however four previously unreported genera were observed in both Lakes Fryxell and Hoare. The variability in the depth distributions of ciliates in Lake Fryxell is explained in terms of lake physicochemical properties and ciliate prey distributions, while factors related to temporal succession in the Lake Hoare assemblage remain unexplained. Local marine or temperate zone freshwater habitats are a more likely source than the surrounding dry valleys soils for present ciliate colonists in these lakes. Although the taxonomic uncertainties require further examination, our results suggest that ciliate populations in these antarctic lakes undergo significant fluctuations and are more diverse than was previously recognized. C1 Univ Nevada, Desert Res Inst, Ctr Biol Sci, Reno, NV 89506 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Kepner, RL (reprint author), Univ Nevada, Desert Res Inst, Ctr Biol Sci, POB 60220, Reno, NV 89506 USA. NR 72 TC 17 Z9 19 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4060 J9 POLAR BIOL JI Polar Biol. PD MAY PY 1999 VL 21 IS 5 BP 285 EP 294 DI 10.1007/s003000050364 PG 10 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 193ZC UT WOS:000080166800003 PM 11543522 ER PT J AU Correll, DL AF Correll, DL TI Phosphorus: A rate limiting nutrient in surface waters SO POULTRY SCIENCE LA English DT Article DE phosphorus; water quality; eutrophication; Redfield ratio; mineral nutrient ID PHYTOPLANKTON GROWTH; CHEMICAL-COMPOSITION; PLANKTONIC ALGAE; FRESH-WATER; LIMITATION; LAKES; PHOSPHATE; ENRICHMENT; NITROGEN; CHLOROPHYLL AB Phosphorus is an essential element for all life forms. It is a mineral nutrient. Orthophosphate is the only form of P that autotrophs can assimilate. Extracellular enzymes hydrolyze organic forms of P to phosphate. Eutrophication is the over-enrichment of surface waters with mineral nutrients. The results are excessive production of autotrophs, especially algae and cyanobacteria. This high productivity leads to high bacterial populations and high respiration rates, leading to hypoxia or anoxia in poorly mixed bottom waters and at night in surface waters during calm, warm conditions. Low dissolved oxygen causes the loss of aquatic animals and the release of many materials normally bound to bottom sediments, including various forms of P. This release of P reinforces the eutrophication. Excessive concentrations of P is the most common cause of eutrophication in freshwater lakes, reservoirs, streams, and in the headwaters of estuarine systems. In the ocean, N is believed to usually be the key mineral nutrient controlling primary production. Estuaries and continental shelf waters are a transition zone, in which excessive P and N create problems. It is best to measure and regulate total P inputs to whole aquatic ecosystems, but for an easy assay it is best to measure total P concentrations, including particulate P, in surface waters or N:P atomic ratios in phytoplankton. C1 Smithsonian Environm Res Ctr, Edgewater, MD 20137 USA. RP Correll, DL (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 20137 USA. NR 70 TC 90 Z9 104 U1 7 U2 63 PU POULTRY SCIENCE ASSOC INC PI SAVOY PA 1111 NORTH DUNLAP AVE, SAVOY, IL 61874 USA SN 0032-5791 J9 POULTRY SCI JI Poult. Sci. PD MAY PY 1999 VL 78 IS 5 BP 674 EP 682 PG 9 WC Agriculture, Dairy & Animal Science SC Agriculture GA 187AU UT WOS:000079764400010 PM 10228963 ER PT J AU McClintock, JE AF McClintock, JE TI A black hole caught in the act SO SCIENTIFIC AMERICAN LA English DT Article C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP McClintock, JE (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SCI AMERICAN INC PI NEW YORK PA 415 MADISON AVE, NEW YORK, NY 10017 USA SN 0036-8733 J9 SCI AM JI Sci.Am. PD MAY PY 1999 VL 280 IS 5 BP 45 EP 45 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 189MW UT WOS:000079910000023 ER PT J AU Hosack, DA Miller, KV Ware, LH Mashburn, KL Morrow, CJ Williamson, LR Marchinton, RL Monfort, SL AF Hosack, DA Miller, KV Ware, LH Mashburn, KL Morrow, CJ Williamson, LR Marchinton, RL Monfort, SL TI Stag exposure advances the LH surge and behavioral estrus in Eld's deer hinds after CIDR device synchronization of estrus SO THERIOGENOLOGY LA English DT Article DE luteinizing hormone; cervid; Eld's deer ID LUTEINIZING-HORMONE; ESTROUS SYNCHRONIZATION; CERVUS-ELAPHUS; ANESTROUS EWES; FALLOW DEER; DAMA-DAMA; SECRETION; THAMIN; OVULATION; GOATS AB The impact of male presence or absence on the timing of the preovulatory LH surge and estrus was studied in 3 experimental groups (n = 6/group) of Eld's deer hinds pretreated with intravaginal progesterone-releasing devices (CIDR-type G) as follows: Group 1 = indirect male contact barn; Group 2 = direct male contact barn; and Group 3 = male isolation barn. For all hinds, the duration of the preovulatory LH surge averaged 2.5 +/- 0.5 h, whereas mean peak preovulatory and basal LH concentrations were 2.9 +/- 0.2 ng mL(-1) and 0.27 +/- 0.03 ng mL(-1), respectively. Nine of 12 male-exposed hinds exhibited a preovulatory LH surge within 24 to 32 h postCIDR device withdrawal, whereas 0 of 6 male-isolated hinds exhibited a preovulatory LH surge during the same time period. Onset of behavioral estrus (45.2 +/- 2.3, 52.7 +/- 5.7, and 66.3 +/- 1.8 h, respectively) was significantly advanced (P < 0.05) after CIDR device withdrawal in male exposed hinds (Groups 1 and 2) compared with male isolated hinds (Group 3). These data suggest that stag exposure is important for modulating the timing of the preovulatory LH surge and behavioral estrus after synchronization of estrus with exogenous progestagens. (C) 1999 by Elsevier Science Inc. C1 Univ Georgia, Sch Forest Resources, Athens, GA 30602 USA. Smithsonian Inst, Conservat & Res Ctr, Natl Zool Pk, Front Royal, VA 22630 USA. RP Hosack, DA (reprint author), Univ Georgia, Sch Forest Resources, Athens, GA 30602 USA. NR 39 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0093-691X J9 THERIOGENOLOGY JI Theriogenology PD MAY PY 1999 VL 51 IS 7 BP 1333 EP 1342 DI 10.1016/S0093-691X(99)00077-1 PG 10 WC Reproductive Biology; Veterinary Sciences SC Reproductive Biology; Veterinary Sciences GA 210VD UT WOS:000081124600012 PM 10729097 ER PT J AU Schultz, TR AF Schultz, TR TI Ants, plants and antibiotics SO NATURE LA English DT Editorial Material ID FUNGUS-GROWING ANTS C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, Washington, DC 20560 USA. RP Schultz, TR (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, MRC 163, Washington, DC 20560 USA. NR 13 TC 8 Z9 10 U1 1 U2 4 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD APR 29 PY 1999 VL 398 IS 6730 BP 747 EP 748 DI 10.1038/19619 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 192BL UT WOS:000080058100022 ER PT J AU Currie, CR Scott, JA Summerbell, RC Malloch, D AF Currie, CR Scott, JA Summerbell, RC Malloch, D TI Fungus-growing ants use antibiotic-producing bacteria to control garden parasites SO NATURE LA English DT Article ID SYMBIOSIS AB The well-studied, ancient and highly evolved mutualism between fungus-growing ants and their fungi has become a model system in the study of symbiosis(1-5). Although it is thought at present to involve only two symbionts, associated with each other in near isolation from other organisms(1-5), the fungal gardens of attine ants are in fact host to a specialized and virulent parasitic fungus of the genus Escovopsis (Ascomycotina)(6). Because the ants and their fungi are mutually dependent, the maintenance of stable fungal monocultures in the presence of weeds or parasites is critical to the survival of both organisms. Here we describe a new, third mutualist in this symbiosis, a filamentous bacterium (actinomycete) of the genus Streptomyces that produces antibiotics specifically targeted to suppress the growth of the specialized garden-parasite Escovopsis. This third mutualist is associated with all species of fungus-growing ants studied, is carried upon regions of the ants' cuticle that are genus specific, is transmitted vertically (from parent to offspring colonies), and has the capacity to promote the growth of the fungal mutualist, indicating that the association of Streptomyces with attine ants is both highly evolved and of ancient origin. C1 Smithsonian Trop Res Inst, Balboa, Panama. Univ Toronto, Dept Bot, Toronto, ON M5S 3B2, Canada. Univ Toronto, Dept Lab Med & Pathobiol, Toronto, ON M5S 3B2, Canada. Ontario Minist Hlth, Toronto, ON M9P 3T1, Canada. RP Currie, CR (reprint author), Smithsonian Trop Res Inst, POB 2072, Balboa, Panama. RI Scott, James/A-8598-2011 OI Scott, James/0000-0002-5073-0832 NR 23 TC 383 Z9 401 U1 11 U2 198 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD APR 22 PY 1999 VL 398 IS 6729 BP 701 EP 704 DI 10.1038/19519 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 189RP UT WOS:000079920100049 ER PT J AU Di Matteo, T Celotti, A Fabian, AC AF Di Matteo, T Celotti, A Fabian, AC TI Magnetic flares in accretion disc coronae and the spectral states of black hole candidates: the case of GX339-4 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; magnetic fields; radiation mechanisms : thermal binaries : general; stars : individual : GX339-4 ID SIMULTANEOUS X-RAY; GX 339-4; HARD STATE; OPTICAL OBSERVATIONS; GX-339-4; TRANSITION; MODEL; OSSE; FLUX AB We examine the constraints that the observations of different spectral states displayed by Galactic black hole candidates impose on the properties of magnetic flares resulting from the reconnection of flux tubes that rise from the accretion disc into a corona because of the magnetic buoyancy (Parker) instability. Using observations of one of the best-studied examples, GX339-4, we identify the geometry and physical conditions characterizing each of these states. We find that, if in the soft state flaring occurs at small scaleheights above the accretion disc, a soft thermal-like spectrum, characteristic of this state, can result from the heating and consequent reradiation of the hard X-rays produced by such flares. The hard tail can then be produced by Comptonization of the soft radiation. Conversely, the hard state may result from a phase in which flares are triggered high above the underlying accretion disc and produce X-rays via Comptonization of either internal cyclo-synchrotron radiation or soft disc photons. The spectral characteristics of the different states are naturally accounted for by the choice of geometry: when flares are triggered high above the disc the system is photon-starved, hence the hard Comptonized spectrum of the hard state. Intense flaring close to the disc greatly enhances the local soft-photon field with the result that the spectrum softens. We interpret these two states as being related to two different phases of magnetic energy dissipation. We speculate that, in the soft state, Parker instability in the disc may favour the emergence of large numbers of relatively low-magnetic-field flux tubes. In the hard state, only intense magnetic fields become buoyant and magnetic loops are able to rise and expand in the coronal atmosphere. This possibility can also qualitatively account for the observed short time-scale variability and the characteristics of the X-ray-reflected component of the hard state. C1 Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. SISSA, I-34014 Trieste, Italy. RP Di Matteo, T (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS51, Cambridge, MA 02138 USA. RI Di Matteo, Tiziana/O-4762-2014 OI Di Matteo, Tiziana/0000-0002-6462-5734 NR 38 TC 59 Z9 59 U1 1 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD APR 21 PY 1999 VL 304 IS 4 BP 809 EP 820 DI 10.1046/j.1365-8711.1999.02375.x PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194EJ UT WOS:000080178900014 ER PT J AU Yan, M Federman, SR Dalgarno, A Bjorkman, JE AF Yan, M Federman, SR Dalgarno, A Bjorkman, JE TI Theoretical modeling of ISO results on planetary nebula NGC 7027 SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : ISM : lines and bands; ISM : molecules; molecular processes; planetary nebulae : individual (NGC 7027) ID MOLECULAR-HYDROGEN EMISSION; PHOTODISSOCIATION REGIONS; ROTATIONAL-EXCITATION; INFRARED RESPONSE; LINE EMISSION; NGC-7027; CLOUDS; GAS; OH; COEFFICIENTS AB We present a thermal and chemical model of the neutral envelope of planetary nebula NGC 7027. In our model, the neutral envelope is composed of a thin dense shell of constant density and an outer stellar wind region with the usual inverse-square law density profile. The thermal and chemical structure is calculated with the assumption that the incident radiation field on the inner surface equals 0.5 x 10(5) times Draine's fit to the average interstellar far-ultraviolet field. The rate coefficient for H-2 formation on grains is assumed to be 1/5 the usual value to take into account the lower dust-gas mass ratio in the neutral envelope of NGC 7027. The calculated temperature in the dense shell decreases from 3000 to under 200 K. Once the temperature drops to 200 K, we assume that it remains at 200 K until the outer edge of the dense shell is reached, so that the observed intensities of CO J = 16-15, 15-14, and 14-13 lines can be reproduced. The 200 K temperature can be interpreted as the average temperature of the shocked gas just behind the forward shock front in the framework of the interacting stellar wind theory. We calculate the intensities of the molecular far-infrared rotational lines by using a revised version of the escape probability formalism. The theoretical intensities for rotational lines of CO (from J = 29-28 to J = 14-13), CH+, OH, and CH are shown to be in good agreement with ISO observations. The H-2 rovibrational line intensities are also calculated and are in agreement with available observations. C1 Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Yan, M (reprint author), Univ Toledo, Dept Phys & Astron, 2801 W Bancroft St, Toledo, OH 43606 USA. NR 46 TC 21 Z9 21 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1999 VL 515 IS 2 BP 640 EP 648 DI 10.1086/307047 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 200EW UT WOS:000080527500019 ER PT J AU Kemper, C Spaans, M Jansen, DJ Hogerheijde, MR van Dishoeck, EF Tielens, AGGM AF Kemper, C Spaans, M Jansen, DJ Hogerheijde, MR van Dishoeck, EF Tielens, AGGM TI Far-infrared and submillimeter observations and physical models of the reflection nebula Cederblad 201 SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; ISM : individual (Cederblad 201); molecular processes; reflection nebulae ID PHOTON-DOMINATED REGIONS; PHOTODISSOCIATION REGIONS; INTERSTELLAR CLOUDS; EMISSION; GAS; TEMPERATURE; RADIATION; GEOMETRY; S-140; DUST AB Infrared Space Observatory (ISO) CC nl 158 mu m, [O I] 63 mu m, and H-2 9 and 17 mu m observations are presented of the reflection nebula Ced 201, which is a photon-dominated region (PDR) illuminated by a B9.5 star with a color temperature of 10,000 K (a cool PDR). In combination with ground-based [C I] 609 mu m, CO, (CO)-C-13, CS, and HCO+ data, the carbon budget and physical structure of the reflection nebula are constrained. The obtained data set is the first one to contain all important cooling lines of a cool PDR and allows a comparison to be made with classical PDRs, To this effect one- and three-dimensional PDR models are presented that incorporate the physical characteristics of the source and are aimed at understanding the dominant heating processes of the cloud. The contribution of very small grains to the photoelectric heating rate is estimated from these models and is used to constrain the total abundance of polycyclic aromatic hydrocarbons and small grains. Observations of the pure rotational H-2 lines with ISO, in particular the S(3) line, indicate the presence of a small amount of very warm similar to 330 K molecular gas. This gas cannot be accommodated by the presented models. C1 Leiden Observ, NL-2300 RA Leiden, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. RP Kemper, C (reprint author), Univ Amsterdam, Kruislaan 403, Amsterdam, Netherlands. RI Kemper, Francisca/D-8688-2011 OI Kemper, Francisca/0000-0003-2743-8240 NR 30 TC 19 Z9 19 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1999 VL 515 IS 2 BP 649 EP 656 DI 10.1086/307053 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 200EW UT WOS:000080527500020 ER PT J AU Barth, AJ Filippenko, AV Moran, EC AF Barth, AJ Filippenko, AV Moran, EC TI Polarized broad H alpha emission from the liner nucleus of NGC 1052 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 1052); galaxies : nuclei; polarization ID ELLIPTICAL GALAXY NGC-1052; ACTIVE GALACTIC NUCLEI; DWARF SEYFERT NUCLEI; PHOTOIONIZATION MODELS; RADIATION; SPECTRUM; QUASARS; SEARCH AB Optical spectropolarimetry of the nucleus of the LINER NGC 1052 obtained at the Keck Observatory reveals a rise in polarization in the wings of the H alpha line profile. The polarization vector of H alpha is offset by 67 degrees from the parsec-scale radio axis and by 83 degrees from the kiloparsec-scale radio axis, roughly in accord with expectations for scattering within the opening cone of an obscuring torus. The broad component of H alpha has FWHM approximate to 2100 km s(-1) in total flux and FWHM approximate to 5000 km s(-1) in polarized light. Scattering by electrons is the mechanism most likely responsible for this broadening, and we find T-e approximate to 10(5) K for the scattering medium, similar to values observed in Seyfert 2 nuclei. This is the first detection of a polarized broad emission line in a LINER, demonstrating that unified models of active galactic nuclei are applicable to at least some LINERs. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. RP Barth, AJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 34 TC 31 Z9 31 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1999 VL 515 IS 2 BP L61 EP L64 DI 10.1086/311976 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 200EY UT WOS:000080527700005 ER PT J AU Narayan, R Raymond, J AF Narayan, R Raymond, J TI Thermal X-ray line emission from accreting black holes SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; galaxies : nuclei; Galaxy : center; radiation mechanisms : thermal; X-rays : stars ID ADVECTION-DOMINATED ACCRETION; DIELECTRONIC SATELLITE SPECTRA; HELIUM-LIKE IONS; RATE COEFFICIENTS; A-ASTERISK; MODEL; EXCITATION; IRON; PLASMAS; SHELL AB We present model X-ray spectra of accreting black holes with hot advection-dominated accretion flows, paying attention to thermal emission lines from the hot plasma. We discuss the emission-line diagnostics that are potentially observable with the next generation of X-ray observatories, emphasizing the possibilities for determining the outer radius of the hot plasma, the presence of a wind, and the relative importance of photoionization. We present example spectra of V404 Cyg in quiescence, the Galactic center black hole Sagittarius A*, and the nucleus of M87. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Narayan, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Narayan, Ramesh/0000-0002-1919-2730 NR 29 TC 39 Z9 41 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1999 VL 515 IS 2 BP L69 EP L72 DI 10.1086/311973 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 200EY UT WOS:000080527700007 ER PT J AU Wills, BJ Laor, A Brotherton, MS Wills, D Wilkes, BJ Ferland, GJ Shang, ZH AF Wills, BJ Laor, A Brotherton, MS Wills, D Wilkes, BJ Ferland, GJ Shang, ZH TI The PG X-ray QSO sample: Links between the ultraviolet-X-ray continuum and emission lines SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; galaxies : starburst; quasars : emission lines; quasars : general; ultraviolet : galaxies; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; FE-II EMISSION; C-IV; EVOLUTION; GALAXY AB Two sets of relationships relate QSO UV to soft X-ray continua with the broad-line region. These are (i) the Baldwin relationships, which are inverse relationships between the broad-line equivalent width and the continuum luminosity, and (ii) Boroson & Green's optical "Principal Component 1" relationships, linking steeper soft Xray spectra with narrower H beta emission, stronger HP blue wings, stronger optical Fe II emission, and weaker [O III] lambda 5007 lines. In order to understand these relationships, we extended the spectra into the UV for 22 QSOs with high-quality soft X-ray spectra. These are from the complete sample of QSOs from the Bright Quasar Survey for which Laor et al. demonstrated strong luminosity and X-ray-optical Principal Component 1 relationships. We show that these extend to a whole new set of UV relationships: Principal Component 1 (in the sense of steeper X-ray spectra) is related to narrower C III] lambda 1909 lines, larger Si III] lambda 1892/C III] lambda 1909 ratios (a high-density indicator), stronger low-ionization lines, and weaker C IV lambda 1549 but stronger N V lambda 1240 lines. We speculate that high accretion rates are linked to high columns of dense (similar to 10(11) cm(-3)), nitrogen-enhanced, low-ionization gas from nuclear starbursts. Line width, inverse Fe II-[O III] and inverse Fe II-C IV relationships hint at the geometrical arrangement of this gas. These Principal Component 1 relationships appear to be independent of luminosity and therefore of the Baldwin relationships. C1 Univ Texas, McDonald Obser, Austin, TX 78712 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. RP Wills, BJ (reprint author), Univ Texas, McDonald Obser, RLM 15-308, Austin, TX 78712 USA. OI Wilkes, Belinda/0000-0003-1809-2364; Ferland, Gary/0000-0003-4503-6333 NR 26 TC 61 Z9 61 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1999 VL 515 IS 2 BP L53 EP L56 DI 10.1086/311980 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 200EY UT WOS:000080527700003 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI Off limits: Rutgers University and the avant-garde, 1957-1963. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Lib, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD APR 15 PY 1999 VL 124 IS 7 BP 84 EP 84 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 185WM UT WOS:000079694000037 ER PT J AU Kirshner, RP AF Kirshner, RP TI Supernovae, an accelerating universe and the cosmological constant SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID IA SUPERNOVAE AB Observations of supernova explosions halfway back to the Big Bang give plausible evidence that the expansion of the universe has been accelerating since that epoch, approximately 8 billion years ago and suggest that energy associated with the vacuum itself may be responsible for the acceleration. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kirshner, RP (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 26 TC 23 Z9 23 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD APR 13 PY 1999 VL 96 IS 8 BP 4224 EP 4227 DI 10.1073/pnas.96.8.4224 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 187BP UT WOS:000079766500005 PM 10200242 ER PT J AU Silbermann, NA Harding, P Ferrarese, L Stetson, PB Madore, BF Kennicutt, RC Freedman, WL Mould, JR Bresolin, F Ford, H Gibson, BK Graham, JA Han, MS Hoessel, JG Hill, RJ Huchra, J Hughes, SMG Illingworth, GD Kelson, D Macri, L Phelps, R Rawson, D Sakai, S Turner, A AF Silbermann, NA Harding, P Ferrarese, L Stetson, PB Madore, BF Kennicutt, RC Freedman, WL Mould, JR Bresolin, F Ford, H Gibson, BK Graham, JA Han, MS Hoessel, JG Hill, RJ Huchra, J Hughes, SMG Illingworth, GD Kelson, D Macri, L Phelps, R Rawson, D Sakai, S Turner, A TI The hubble space telescope key project on the extragalactic distance scale. XIV. The cepheids in NGC 1365 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cepheids; galaxies, distances and redshifts; galaxies, individual (NGC 1365) ID TULLY-FISHER RELATION; RR-LYRAE STARS; H-II-REGIONS; STELLAR PHOTOMETRY; SPIRAL GALAXIES; FORNAX CLUSTER; CCD PHOTOMETRY; DISCOVERY; PERFORMANCE; CALIBRATION AB We report the detection of Cepheid variable stars in the barred spiral galaxy NGC 1365, located in the Fornax cluster, using the Hubble Space Telescope (HST) Wide Field and Planetary Camera 2 (WFPC2). Twelve V (F555W) and four I (F814W) epochs of observation were obtained. The two photometry packages ALLFRAME and DoPHOT were separately used to obtain profile-fitting photometry of all the stars in the HST held. The search for Cepheid variable stars resulted in a sample of 52 variables, with periods between 14 and 60 days, common to both data sets. ALLFRAME photometry and light curves of the Cepheids are presented. A subset of 34 Cepheids were selected on the basis of period, light curve shape, similar ALLFRAME and DoPHOT periods, color, and relative crowding, to lit the Cepheid period-luminosity relations in V and I for both ALLFRAME and DoPHOT. The measured distance modulus to NGC 1365 from the ALLFRAME photometry is 31.31 +/- 0.20 (random) +/- 0.18 (systematic) mag, corresponding to a distance of 18.3 +/- 1.7 (random) +/- 1.6 (systematic) Mpc. The reddening is measured to be E(V - I) = 0.16 +/- 0.08 mag. These values are in excellent agreement with those obtained using the DoPHOT photometry, namely a distance modulus of 31.26 +/- 0.10 mag and a reddening of 0.15 +/- 0.10 mag (internal errors only). C1 CALTECH, Jet Prop Lab, Infrared Proc & Anal Ctr, NASA Extragalact Database, Pasadena, CA 91125 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Inst Adv Studies, Weston, ACT 2611, Australia. Johns Hopkins Univ, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. Univ Wisconsin, Madison, WI 53706 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Royal Greenwich Observ, Cambridge CB3 0EZ, England. Univ Calif Santa Cruz, Lick Observ, Santa Cruz, CA 95064 USA. RP Silbermann, NA (reprint author), CALTECH, Jet Prop Lab, Infrared Proc & Anal Ctr, NASA Extragalact Database, MS 100-22, Pasadena, CA 91125 USA. RI Gibson, Brad/M-3592-2015 OI Gibson, Brad/0000-0003-4446-3130 NR 59 TC 41 Z9 41 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1999 VL 515 IS 1 BP 1 EP 28 DI 10.1086/307002 PN 1 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 195AF UT WOS:000080226400001 ER PT J AU Madore, BF Freedman, WL Silbermann, N Harding, P Huchra, J Mould, JR Graham, JA Ferrarese, L Gibson, BK Han, MS Hoessel, JG Hughes, SM Illingworth, GD Phelps, R Sakai, S Stetson, P AF Madore, BF Freedman, WL Silbermann, N Harding, P Huchra, J Mould, JR Graham, JA Ferrarese, L Gibson, BK Han, MS Hoessel, JG Hughes, SM Illingworth, GD Phelps, R Sakai, S Stetson, P TI The Hubble Space Telescope key project on the extragalactic distance scale. XV. A Cepheid distance to the Fornax cluster and its implications SO ASTROPHYSICAL JOURNAL LA English DT Article DE Cepheids; distance scale; galaxies : clusters : individual (Fornax); galaxies : distances and redshifts; galaxies : individual (NGC 1365) ID TULLY-FISHER RELATION; LINE-WIDTH RELATIONS; LOCAL SUPERCLUSTER; SPIRAL GALAXIES; VELOCITY-FIELD; EXPANSION RATE; CONSTANT; IA; CALIBRATION; BRIGHTNESS AB Using the Hubble Space Telescope, 37 long-period Cepheid variables have been discovered in the Fornax Cluster spiral galaxy NGC 1365. The resulting V and I period-luminosity relations yield a true distance modulus of mu(0) = 31.35 +/- 0.07 mag, which corresponds to a distance of 18.6 +/- 0.6 Mpc. This measurement provides several routes for estimating the Hubble constant. (1) Assuming this distance for the Fornax Cluster as a whole yields a local Hubble constant of 70 +/- 18 (random) +/- 7 (systematic) km s(-1) Mpc(-1). (2) Nine Cepheid-based distances to groups of galaxies out to and including the Fornax and Virgo Clusters yield H-0 = 73 +/- 16 (random) +/- 7 (systematic) km s(-1) Mpc(-1). (3) Recalibrating the I-band Tully-Fisher relation using NGC 1365 and six nearby spiral galaxies, and applying it to 15 galaxy clusters out to 100 Mpc, give H-0 = 76 +/- 3 (random) is (systematic) km s(-1) Mpc(-1). (4) Using a broad-based set of differential cluster distance moduli ranging from Fornax to Abell 2147 gives H-0 = 72 +/- 3 (random) +/- 6(systematic) km s(-1) Mpc(-1). Finally, (5) assuming the NGC 1365 distance for the two additional Type Ia supernovae in Fornax; and adding them to the SN Ia calibration (correcting for light-curve shape) gives H-0 = 67 +/- 6 (random) +/- 7 (systematic) km s(-1) Mpc(-1) out to a distance in excess of 500 Mpc. All five of these H-0 determinations agree to within their statistical errors. The resulting estimate of the Hubble constant, combining all of these determinations, is H-0 = 72 +/- 5 (random) +/- 7 (systematic) km s(-1) Mpc(-1). An extensive tabulation of identified systematic and statistical errors, and their propagation, is given. C1 CALTECH, Jet Prop Lab, NASA, IPAC Extragalact Database,Infrares Proc & Anal Ct, Pasadena, CA 91125 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Inst Adv Studies, Weston, ACT 2611, Australia. Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Royal Greenwich Observ, Cambridge CB3 0HA, England. Univ Calif Santa Cruz, Lick Observ, Santa Cruz, CA 95064 USA. Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada. RP Madore, BF (reprint author), CALTECH, Jet Prop Lab, NASA, IPAC Extragalact Database,Infrares Proc & Anal Ct, MS 100-22, Pasadena, CA 91125 USA. RI Gibson, Brad/M-3592-2015 OI Gibson, Brad/0000-0003-4446-3130 NR 74 TC 76 Z9 76 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1999 VL 515 IS 1 BP 29 EP 41 DI 10.1086/307004 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 195AF UT WOS:000080226400002 ER PT J AU Pahre, MA Mould, JR Dressler, A Holtzman, JA Watson, AM Gallagher, JS Ballester, GE Burrows, CJ Casertano, S Clarke, JT Crisp, D Griffiths, RE Grillmair, CJ Hester, JJ Hoessel, JG Scowen, PA Stapelfeldt, KR Trauger, JT Westphal, JA AF Pahre, MA Mould, JR Dressler, A Holtzman, JA Watson, AM Gallagher, JS Ballester, GE Burrows, CJ Casertano, S Clarke, JT Crisp, D Griffiths, RE Grillmair, CJ Hester, JJ Hoessel, JG Scowen, PA Stapelfeldt, KR Trauger, JT Westphal, JA TI Detection of surface brightness fluctuations in NGC 4373 using the Hubble Space Telescope SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : distances and redshifts; galaxies : elliptical and lenticular, cD; galaxies : individual (NGC 4373); galaxies : stellar content ID MEASURING EXTRAGALACTIC DISTANCES; VIRGO CLUSTER; ELLIPTICAL GALAXIES; SAMPLE SELECTION; PHOTOMETRY; CALIBRATION; CONSTANT; WFPC2; FIELD; SPECTROSCOPY AB Surface brightness fluctuations (SBF) have been detected for three elliptical galaxies-NGC 3379 in the Leo group, NGC 4406 in the Virgo cluster, and NGC 4373 in the Hydra-Centaurus supercluster-using marginally sampled, deep images taken with the Planetary Camera of the WFPC2 instrument on the Hubble Space Telescope (HST). The power spectrum of the fluctuations image is well fitted by an empirical model of the point-spread function constructed using point sources identified in the held. Comparison with high-quality ground-based observations of all three galaxies show excellent agreement in the measurement of the distance modulus over a substantial range in distance. This demonstrates the capability of the Planetary Camera of WFPC2 to measure distances using the SBF technique despite the marginal sampling and small spatial coverage of the images. The residual variance due to unresolved sources in all three galaxies is only 2%-5% of the detected fluctuations signal, which confirms the advantage of HST imaging in minimizing the uncertainty of this SBF correction. Extensive consistency checks, including an independent SBF analysis using an alternate software package, suggest that our internal uncertainties are <0.02 mag. The fluctuations magnitude for NGC 4373 is I-F814W = 31.31 +/- 0.05 mag, corresponding to a distance modulus of (m-M)(0) = 32.99 +/- 0.11. This implies a peculiar velocity for this galaxy of 415 +/- 330 km s(-1), which is smaller than derived from the D-n-sigma relation. C1 CALTECH, Palomar Observ, Pasadena, CA 91125 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Inst Adv Studies, Weston, ACT 2611, Australia. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Johns Hopkins Univ, Dept Astron, Baltimore, MD 21218 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Pahre, MA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,Mail Stop 20, Cambridge, MA 02138 USA. RI Stapelfeldt, Karl/D-2721-2012; Clarke, John/C-8644-2013 NR 36 TC 21 Z9 21 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1999 VL 515 IS 1 BP 79 EP 88 DI 10.1086/306998 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 195AF UT WOS:000080226400006 ER PT J AU Mihos, JC Spaans, M McGaugh, SS AF Mihos, JC Spaans, M McGaugh, SS TI The molecular ISM in low surface brightness disk galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, evolution; galaxies, ISM; galaxies, spiral; galaxies, structure; ISM, molecules; ISM, structure ID STAR-FORMATION; SPIRAL GALAXIES; INTERSTELLAR-MEDIUM; OXYGEN ABUNDANCES; GAS; PHOTOMETRY; MODELS; RATIO; CLUES AB We present models for the interstellar medium in disk galaxies. In particular, we investigate whether the ISM in low surface brightness galaxies can support a significant fraction of molecular gas given their low metallicity and surface density. It is found that the abundance and line brightness of CO in LSB galaxies is small and typically below current observational limits. Still, depending on physical details of the ISM, the fraction of gas in the form of molecular hydrogen can be significant in the inner few kiloparsecs of a low surface brightness galaxy. This molecular gas would be at temperatures of similar to 3-50 K, rather higher than in high surface brightness galaxies. These results may help explain the star-forming properties and inferred evolutionary history of LSB galaxies. C1 Case Western Reserve Univ, Dept Astron, Cleveland, OH 44106 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Mihos, JC (reprint author), Case Western Reserve Univ, Dept Astron, 10900 Euclid Ave, Cleveland, OH 44106 USA. NR 45 TC 29 Z9 29 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1999 VL 515 IS 1 BP 89 EP 96 DI 10.1086/307027 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 195AF UT WOS:000080226400007 ER PT J AU Sambruna, RM Ghisellini, G Hooper, E Kollgaard, RI Pesce, JE Urry, CM AF Sambruna, RM Ghisellini, G Hooper, E Kollgaard, RI Pesce, JE Urry, CM TI ASCA and contemporaneous ground-based observations of the BL Lacertae objects 1749+096 and 2200+420 (BL Lac) SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : individual (1749+096); BL Lacertae objects : individual (2200+420); galaxies : active; radiation mechanisms : nonthermal; X-rays : galaxies ID X-RAY-SPECTRA; EXTRAGALACTIC RADIO-SOURCES; ACTIVE GALACTIC NUCLEI; LOCAL INTERSTELLAR CO; GAMMA-RAY; MULTIFREQUENCY OBSERVATIONS; ENERGY-DISTRIBUTIONS; EGRET OBSERVATIONS; COMPLETE SAMPLE; BLAZARS AB We present ASCA observations of the radio-selected BL Lacertae objects 1749+096 (z = 0.32) and 2300+420 (BL Lac, z = 0.069) performed in 1995 September and November, respectively. The ASCA spectra of both sources can be described as a first approximation by a power law with photon index Gamma similar to 2. This is flatter than for most X-ray-selected BL Lacs observed with ASCA, in agreement with the predictions of current blazar unification models. While 1749+096 exhibits tentative evidence for spectral flattening at low energies, a concave continuum is detected for 2200+420: the steep low-energy component is consistent with the high-energy tail of the synchrotron emission responsible for the longer wavelengths, while the harder tail at higher energies is the onset of the Compton component. The two BL Lacs were observed with ground-based telescopes from radio to TeV energies contemporaneously with ASCA. The spectral energy distributions are consistent with synchrotron self-Compton emission from a single homogeneous region shortward of the IR/optical wavelengths, with a second component in the radio domain related to a more extended emission region. For 2200+420, comparing the 1995 November state with the optical/GeV flare of 1997 July, we find that models requiring inverse Compton scattering of external photons provide a viable mechanism for the production of the highest (GeV) energies during the flare. In particular, an increase of the external radiation density and of the power injected in the jet can reproduce the flat gamma-ray continuum observed in 1997 July. A directly testable prediction of this model is that the line luminosity in 2200+420 should vary shortly after(similar to 1 month) a nonthermal synchrotron flare. C1 Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Osservatorio Astron Brera, I-22055 Merate, LC, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Sambruna, RM (reprint author), Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. RI Urry, Claudia/G-7381-2011 OI Urry, Claudia/0000-0002-0745-9792 NR 65 TC 35 Z9 36 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1999 VL 515 IS 1 BP 140 EP 152 DI 10.1086/307005 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 195AF UT WOS:000080226400011 ER PT J AU Alves, J Lada, CJ Lada, EA AF Alves, J Lada, CJ Lada, EA TI Correlation between gas and dust in molecular clouds: L977 SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; ISM : abundances; ISM : individual (L977, L981); ISM : molecules; ISM : structure ID INTER-STELLAR CLOUDS; DESORPTION; EXTINCTION AB We report observations of the J = (1-0) (CO)-O-18 molecular emission line toward the L977 molecular cloud. To study the correlation between (CO)-O-18 emission and dust extinction we constructed a Gaussian smoothed map of the infrared extinction measured by Alves et al. at the same angular resolution (50 ") as our molecular-line observations. This enabled a direct comparison of (CO)-O-18 integrated intensities and column densities with dust extinction over a relatively large range of cloud depth (2 < A(V) < 30 mag) at 240 positions inside L977. We find a good linear correlation between these two column density tracers for cloud depths corresponding to A(V) less than or similar to 10 mag. For cloud depths above this threshold there is a notable break in the linear correlation. Although either optically thick (CO)-O-18 emission or extremely low (T-ex < 5 K) excitation temperatures at high extinctions could produce this departure from linearity, CO depletion in the denser, coldest regions of L977 may be the most likely cause of the break in the observed correlation. We directly derive the (CO)-O-18 abundance in this cloud over a broad range of cloud depths and find it to be virtually the same as that derived for IC 5146 from the data of Lada et al. In regions of very high extinction (A(V) > 10 mag), such as dense cores, our results suggest that (CO)-O-18 would be a very poor tracer of mass. Consequently, using (CO)-O-18 as a column density tracer in molecular clouds can lead to a 10% to 30% underestimation of overall cloud mass. We estimate the minimum total column density required to shield (CO)-O-18 from the interstellar radiation field to be 1.6 +/- 0.5 mag of visual extinction. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Florida, Dept Astron, Gainesville, FL 32608 USA. Univ Lisbon, Dept Phys, P-1699 Lisbon, Portugal. RP Alves, J (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 19 TC 70 Z9 70 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1999 VL 515 IS 1 BP 265 EP 274 DI 10.1086/307003 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 195AF UT WOS:000080226400022 ER PT J AU Wood, B Collard, M AF Wood, B Collard, M TI Anthropology - The human genus SO SCIENCE LA English DT Review ID BODY-MASS; AUSTRALOPITHECUS-AFRICANUS; MIDDLE PLEISTOCENE; FOSSIL HOMINIDS; HUMAN-EVOLUTION; OLDUVAI-GORGE; SOUTH-AFRICA; BRAIN-SIZE; EARLY HOMO; HYPOTHESIS C1 George Washington Univ, Dept Anthropol, Washington, DC 20052 USA. Smithsonian Inst, Natl Museum Amer Hist, Human Origins Program, Washington, DC 20560 USA. UCL, Dept Anthropol, London WC1E 6BT, England. RP Wood, B (reprint author), George Washington Univ, Dept Anthropol, 2110 G St NW, Washington, DC 20052 USA. EM bwood@gwu.edu FU Wellcome Trust NR 88 TC 361 Z9 378 U1 34 U2 187 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD APR 2 PY 1999 VL 284 IS 5411 BP 65 EP + DI 10.1126/science.284.5411.65 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 182QE UT WOS:000079509000030 PM 10102822 ER PT J AU Chai, P Dudley, R AF Chai, P Dudley, R TI Maximum flight performance of hummingbirds: Capacities, constraints, and trade-offs SO AMERICAN NATURALIST LA English DT Article DE flight energetics; hummingbirds; morphology; performance; trade-offs ID MIGRANT RUFOUS HUMMINGBIRDS; HOVERING INSECT FLIGHT; WINGBEAT FREQUENCY; METABOLIC RATES; PREDATION RISK; GAS-MIXTURES; BODY-MASS; LIMITS; MOLT; BIRDS AB Flight performance trade-offs and functional capacities of ruby-throated hummingbirds (Archilochus colubris L.) were studied using an integrative approach. Performance limits were measured by noninvasively challenging birds with two strenuous forms of flight: hovering in low-density gas mixtures (a lift assay for the capacity to generate vertical force) and fast forward night in a wind tunnel(a thrust assay for the capacity to generate horizontal force). Functional capacities during hovering were measured by simultaneously collecting metabolic data using respirometry and information on wingbeat kinematics for aerodynamic analysis. Intraspecific differences in flight capacity, presumably reflecting diverse selective forces because of sexual dimorphism, migration, and plumage renewal, were then compared. Birds with Shorter wings (adult males) or with increased body weight displayed a reduced hovering capacity, although their maximum flight speed was unaffected by such morphological changes. Birds undergoing molt of their flight feathers exhibited a diminished performance during both hovering and forward flight. Hovering capacities in relation to variation in wing morphology and body mass were congruent with aerodynamic predictions, whereas performance capacities in fast forward flight differed from theoretical models. Kinematically, hovering hummingbirds operate within a narrow range of wing-beat frequencies, and modulation of aerodynamic forces and mechanical power is achieved primarily through variation in wing-stroke amplitude. Although differing in hovering performance, both sexes. of nonmolt birds demonstrate similar mechanical and metabolic capacities, whereas molting inflicts high energetic costs. Relatively invariant physiological capacities may thus ultimately constrain the extent of intraspecific trade-offs between morphology and performance, providing mechanistic insights into the multilevel functional design of the hummingbird flight system. C1 Univ Texas, Dept Zool, Austin, TX 78712 USA. Smithsonian Trop Res Inst, Balboa, Panama. RP Dudley, R (reprint author), Univ Texas, Dept Zool, Austin, TX 78712 USA. EM r_dudley@utxvmscc.utexas.edu NR 71 TC 38 Z9 38 U1 2 U2 39 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0003-0147 EI 1537-5323 J9 AM NAT JI Am. Nat. PD APR PY 1999 VL 153 IS 4 BP 398 EP 411 DI 10.1086/303179 PG 14 WC Ecology; Evolutionary Biology SC Environmental Sciences & Ecology; Evolutionary Biology GA 189UC UT WOS:000079923700005 ER PT J AU Ryan, MJ Rand, AS AF Ryan, MJ Rand, AS TI Phylogenetic influence on mating call preferences in female tungara frogs, Physalaemus pustulosus SO ANIMAL BEHAVIOUR LA English DT Article ID SEXUAL SELECTION; SENSORY EXPLOITATION; PREEXISTING BIAS; MATE CHOICE; EVOLUTION; BEHAVIOR; CHARACTERS; STATES; MALES; CUES AB We evaluated how various phylogenetic models for estimating ancestral characters can influence studies of behavioural evolution. Previously we used a single model of evolution to estimate the values of call characters at ancestral nodes for the Physalaemus pustulosus species group and some-close relatives (Ryan & Rand 1995, Science, 269, 390-392). We then synthesized these ancestral calls and measured the females' responses to such calls in phonotaxis experiments. We repeated the above procedure to determine the sensitivity of these results and conclusions to various models used to estimate the ancestral call characters. We asked whether: (1) different models gave different call estimates for the same nodes; (2) different call estimates at the same node were perceived as different by females; and (3) differences in female responses influenced previous conclusions. We used seven different models that varied in at least one of the following parameters: tree topology (bifurcating versus pectinate in-group trees), algorithms (local squared-change versus squared-change parsimony), tempo (gradual or punctuated evolution), and outgroups (two or three outgroup taxa used). Although different models often gave different call estimates for the same node, these different estimates often were not perceived as different by the females. These data reinforce our previous conclusions that: (1) the range of female preferences exceeds the known variation of the conspecific call; (2) females do not discriminate between the conspecific call and the call of their most recent ancestor; and (3) female responses may be context dependent, given that females differ in their responses to the same signal variation in discrimination and recognition experiments. (C) 1999 The Association for the Study of Animal Behaviour. C1 Univ Texas, Dept Zool, Austin, TX 78712 USA. Smithsonian Trop Res Inst, Balboa, Panama. RP Ryan, MJ (reprint author), Univ Texas, Dept Zool, Austin, TX 78712 USA. RI Rohlf, F/A-8710-2008 NR 64 TC 39 Z9 42 U1 0 U2 12 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0003-3472 J9 ANIM BEHAV JI Anim. Behav. PD APR PY 1999 VL 57 BP 945 EP 956 DI 10.1006/anbe.1998.1057 PN 4 PG 12 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA 189QL UT WOS:000079916000022 ER PT J AU Xiao, LH Escalante, L Yang, CF Sulaiman, I Escalante, AA Montali, RJ Fayer, R Lal, AA AF Xiao, LH Escalante, L Yang, CF Sulaiman, I Escalante, AA Montali, RJ Fayer, R Lal, AA TI Phylogenetic analysis of Cryptosporidium parasites based on the small-subunit rRNA gene locus SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID FRAGMENT-LENGTH-POLYMORPHISM; POLYMERASE CHAIN-REACTION; RIBOSOMAL-RNA GENES; PCR-RFLP ANALYSIS; OOCYST WALL; PARVUM; APICOMPLEXA; SEQUENCE; RESTRICTION; BOVINE AB Biological data support the hypothesis that there are multiple species in the genus Cryptosporidium, but a recent analysis of the available genetic data suggested that there is insufficient evidence for species differentiation. In order to resolve the controversy in the taxonomy of this parasite genus, we characterized the small-subunit rRNA genes of Cryptosporidium parvum, Cryptosporidium baileyi, Cryptosporinium muris, and Cryptosporidium serpentis and performed a phylogenetic analysis of the genus Cryptosporidium. Our study revealed that the genus Cryptosporidium contains the phylogenetically distinct species C. parvum, C. muris, C. baileyi, and C. serpentis, which is consistent with the biological characteristics and host specificity data. The Cryptosporidium species formed two clades, with C. parvum and C. baileyi belonging to one clade and C. muris and C. serpentis belonging to the other clade. Within C. parvum, human genotype isolates and guinea pig isolates (known as Cryptosporidium wrairi) each differed from bovine genotype isolates by the nucleotide sequence in four regions, A C. muris isolate from cattle was also different from parasites isolated from a rock hyrax and a Bactrian camel. Minor differences were also detected between C. serpentis isolates from snakes and lizards. Based on the genetic information, a species- and strain-specific PCR-restriction fragment length polymorphism diagnostic tool was developed. C1 Ctr Dis Control & Prevent, Div Parasit Dis, Natl Ctr Infect Dis, US Dept HHS, Atlanta, GA 30341 USA. Inst Venezolano Invest Cient, Caracas, Venezuela. Smithsonian Inst, Natl Zool Pk, Dept Pathol, Washington, DC 20008 USA. ARS, Parasite Immunobiol Lab, USDA, Beltsville, MD 20705 USA. RP Lal, AA (reprint author), Div Parasit Dis, Mail Stop F-12,4770 Buford Hwy, Chamblee, GA 30341 USA. EM aall@cdc.gov RI Xiao, Lihua/B-1704-2013; Yang, Chunfu/G-6890-2013 OI Xiao, Lihua/0000-0001-8532-2727; NR 41 TC 396 Z9 444 U1 2 U2 20 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD APR PY 1999 VL 65 IS 4 BP 1578 EP 1583 PG 6 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 183AE UT WOS:000079530000031 PM 10103253 ER PT J AU Strayer, DL Reid, JW AF Strayer, DL Reid, JW TI Distribution of hyporheic cyclopoids (Crustacea : Copepoda) in the eastern United States SO ARCHIV FUR HYDROBIOLOGIE LA English DT Article ID SOUTHEASTERN NEW-YORK; NORTH-AMERICA; INTERSTITIAL HABITATS; STREAM; USA; GROUNDWATER; COMMUNITIES; DISPERSAL; MEIOFAUNA; COLORADO AB We sampled the hyporheic cyclopoid copepods of 14 unpolluted sites in the eastern United States to test whether community composition differed between glaciated and unglaciated sites. We found 31 species of cyclopoids in all, over half of which were new to science or only recently described. All of these newly discovered species were interstitial specialists ("stygobionts") living in the unglaciated Southeast, suggesting that many new species of hyporheic cyclopoids remain to be found in this region. Glaciated sites contained fewer species of interstitial specialists (but not fewer species of generalists) and fewer narrowly endemic species than unglaciated sites. Further, ordination results suggest that there is a break in species composition near the glacial border. In contrast, local ecological conditions had much weaker effects on species composition. We also found strong differences between interstitial specialists and generalists in local distributions within our study sites and in range size-abundance relationships. Our results thus show that glaciation has strong residual effects on the composition of present-day communities of hyporheic cyclopoids. C1 Inst Ecosyst Studies, Millbrook, NY 12545 USA. Smithsonian Inst, Natl Museum Amer Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Strayer, DL (reprint author), Inst Ecosyst Studies, Box AB, Millbrook, NY 12545 USA. RI Strayer, David/H-3788-2011 NR 42 TC 21 Z9 21 U1 0 U2 3 PU E SCHWEIZERBARTSCHE VERLAGS PI STUTTGART PA NAEGELE U OBERMILLER JOHANNESSTRASSE 3A, D 70176 STUTTGART, GERMANY SN 0003-9136 J9 ARCH HYDROBIOL JI Arch. Hydrobiol. PD APR PY 1999 VL 145 IS 1 BP 79 EP 92 PG 14 WC Limnology; Marine & Freshwater Biology SC Marine & Freshwater Biology GA 196CL UT WOS:000080291400005 ER PT J AU Chisholm, JR Harnden, FR Schachter, JF Micela, G Sciortino, S Favata, F AF Chisholm, JR Harnden, FR Schachter, JF Micela, G Sciortino, S Favata, F TI ROSAT High Resolution Imager identifications of suspected stellar sources from the Einstein Slew Survey SO ASTRONOMICAL JOURNAL LA English DT Article DE X-rays ID STARS; CATALOG AB We present analysis of a series of ROSAT High Resolution Imager (HRI) observations of 16 X-ray detections from the Einstein Slew Survey (ESS). The data were taken to resolve ambiguous ESS identifications based on optical spectroscopy. For 10 of the 16 detections, the previous identification has been confirmed-six with solar-type stars (spectral types F-K), one each with a cataclysmic variable, a B2 V, a dMe star, and one with a BL Lac object. For another detection, two potential counterparts are unresolvable even with the HRI. The HRI does resolve two other ESS detections into two distinct X-ray sources, but no HRI source is found for the remaining three X-ray detections. HRI-derived fluxes are consistent with those measured by the ROSAT All-Sky Survey for their 12 common detections, and improved positions are obtained for these sources. We calculate values of f(x)/f(v) and L-x for these stars where possible and find values consistent with those expected for corresponding spectral types. C1 Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron Palermo, I-90134 Palermo, Italy. European Space Agcy, Div Astrophys, NL-2200 AG Noordwijk, Netherlands. RP Chisholm, JR (reprint author), Northwestern Univ, Dept Phys & Astron, 2131 Sheridan Rd, Evanston, IL 60208 USA. NR 23 TC 2 Z9 2 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD APR PY 1999 VL 117 IS 4 BP 1845 EP 1851 DI 10.1086/300812 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194ZK UT WOS:000080224500018 ER PT J AU Kaas, AA Aksnes, K Franklin, F Lieske, J AF Kaas, AA Aksnes, K Franklin, F Lieske, J TI Astrometry from mutual phenomena of the Galilean satellites in 1990-1992 SO ASTRONOMICAL JOURNAL LA English DT Article DE astrometry; ephemerides; planets and satellites : individual (Jupiter) AB This paper derives astrometric data for the Galilean satellites from 213 light curves of 86 mutual eclipses and occultations that occurred in 1990-1992. Comparisons of these data with predictions based on the most precise modern ephemeris (E5) generally show good agreement, although it is rather poorer in the case of J1 (Io). C1 Stockholm Observ, S-13336 Saltsjobaden, Sweden. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kaas, AA (reprint author), Stockholm Observ, S-13336 Saltsjobaden, Sweden. NR 7 TC 12 Z9 12 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD APR PY 1999 VL 117 IS 4 BP 1933 EP 1941 DI 10.1086/300808 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194ZK UT WOS:000080224500026 ER PT J AU Kaper, L Henrichs, HF Nichols, JS Telting, JH AF Kaper, L Henrichs, HF Nichols, JS Telting, JH TI Long- and short-term variability in O-star winds II. Quantitative analysis of DAC behaviour SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : early-type; stars : magnetic fields; stars : mass-loss; stars : oscillations; ultraviolet : stars ID COROTATING INTERACTION REGIONS; NARROW ABSORPTION COMPONENTS; TIME-SERIES OBSERVATIONS; LINE-PROFILE VARIATIONS; STELLAR-WIND; ROTATIONAL VELOCITIES; MAGNETIC-FIELDS; B-SUPERGIANTS; ZETA-PUPPIS; MASS-LOSS AB A quantitative analysis of time series of ultraviolet spectra from a sample of 10 bright O-type stars (cf. Kaper et al. 1996, Paper I) is presented. Migrating discrete absorption components (DACs), responsible for the observed variability in the UV resonance doublets, are modeled. To isolate the DACs from the underlying P Cygni lines, a method is developed to construct a template ("least-absorption'') spectrum for each star. The central velocity, central optical depth, width, and column density of each pair of DACs is measured and studied as a function of time. It turns out that the column density of a DAC first increases and subsequently decreases with time when the component is approaching its asymptotic velocity. Sometimes a DAC vanishes before this velocity is reached. In some cases the asymptotic DAC velocity systematically differs from event to event In order to determine the characteristic timescale(s) of DAC variability, Fourier (CLEAN) analyses have been performed on the time series. The recurrence timescale of DACs is derived for most targets, and consistent results are obtained for different spectral lines. The DAC recurrence timescale is interpreted as an integer fraction of the stellar rotation period. In some datasets the variability in the blue edge of the P Cygni lines exhibits a longer period than the DAC variability. This might be related to the systematic difference in asymptotic velocity of successive DACs. The phase information provided by the Fourier analysis confirms the expected change in phase with increasing velocity. This supports the interpretation that the DACs are responsible for the detected periodicity. The phase diagram for the O giant xi Per shows clear evidence for so-called "phase bowing", which is an observational indication for the presence of curved wind structures like corotating interaction regions in the stellar wind. An important difference with the results obtained for the B supergiant HD 64760 (Fullerton et al. 1997) is that in this O star the phase bowing can be associated with the DACs. No other O stars in our sample convincingly show phase bowing, but this could be simply due to the absence of periodic signal and hence coherent phase behaviour at low wind velocities. C1 European So Observ, D-85748 Garching, Germany. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NFRA, Isaac Newton Grp Telescopes, E-38700 Santa Cruz De La Palma, Spain. RP Kaper, L (reprint author), European So Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany. EM lexk@astro.uva.nl NR 57 TC 79 Z9 82 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD APR PY 1999 VL 344 IS 1 BP 231 EP 262 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 183JA UT WOS:000079549400031 ER PT J AU Kelson, DD Illingworth, GD Saha, A Graham, JA Stetson, PB Freedman, WL Kennicutt, RC Mould, JR Ferrarese, L Huchra, JP Madore, BF Prosser, CF Bresolin, F Ford, HC Gibson, BK Hoessel, JG Hughes, SMG Macri, LM Sakai, S Silbermann, NA AF Kelson, DD Illingworth, GD Saha, A Graham, JA Stetson, PB Freedman, WL Kennicutt, RC Mould, JR Ferrarese, L Huchra, JP Madore, BF Prosser, CF Bresolin, F Ford, HC Gibson, BK Hoessel, JG Hughes, SMG Macri, LM Sakai, S Silbermann, NA TI The Hubble Space Telescope key project on the Extragalactic Distance Scale. XIX. The discovery of Cepheids in and a new distance to NGC 3198 SO ASTROPHYSICAL JOURNAL LA English DT Article DE Cepheids; galaxies : distances and redshifts; galaxies : individual (NGC 3198) ID SPIRAL GALAXIES; ELLIPTICAL GALAXIES; PEAK BRIGHTNESS; CCD PHOTOMETRY; CALIBRATION; SUPERNOVAE; UNIVERSE; CLUSTER; CURVES; STARS AB We report the detection of Cepheid variable stars and a new distance to the Sc spiral NGC 3198. NGC 3198 is one of 25 galaxies that have been observed with the WFPC2 of the Hubble Space Telescope (HST) for the purpose of measuring Cepheid distances. Eighteen of these galaxies were targeted by the HST Key Project on the Extragalactic Distance Scale, whose objective is to calibrate a variety of secondary distant indicators and determine the Hubble constant to an accuracy of 10%. NGC 3198 was selected as part of this sample because its type and orientation make it very suitable as a Tully-Fisher calibrator. The WFPC2 data are comprised of 13 epochs in F555W (similar to V) and five epochs in F814W (similar to I). Two different crowded-held photometry packages (DAOPHOT/ALLFRAME and DoPHOT) were used. The magnitudes derived from these two packages agree to within a few percent. We identified 78 Cepheid candidates in the period range from eight to >50 days, of which 52 were selected for establishing the distance modulus. Period-luminosity relations were constructed in Johnson V and Kron-Cousins I by transforming the F555W and F814W to the standard system. We adopted a distance modulus of mu(o) = 18.50 +/- 0.10 mag and mean reddening of E(B-V) = 0.10 mag to the Large Magellanic Cloud Cepheids and found a true distance modulus to NGC 3198 of mu(o) = 30.80 +/- 0.16 (random) +/- 0.12 (systematic) mag. This modulus corresponds to a distance of 14.5 Mpc, with random and systematic errors of +/- 1.2 and +/- 0.9 Mpc, respectively. C1 Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Board Studies Astron & Astrophys, Santa Cruz, CA 95064 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Inst Adv Studies, Weston, ACT 2611, Australia. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, IPAC, Pasadena, CA 91125 USA. European So Observ, D-85478 Garching, Germany. Johns Hopkins Univ, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Royal Greenwich Observ, Cambridge CB3 0EZ, England. RP Kelson, DD (reprint author), Carnegie Inst Washington, Dept Terr Magnetism, 5241 Broad Branch Rd NW, Washington, DC 20015 USA. RI Gibson, Brad/M-3592-2015; OI Gibson, Brad/0000-0003-4446-3130; Macri, Lucas/0000-0002-1775-4859 NR 48 TC 26 Z9 26 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 1 PY 1999 VL 514 IS 2 BP 614 EP 636 DI 10.1086/306989 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194ZQ UT WOS:000080225000009 ER PT J AU Blitz, L Spergel, DN Teuben, PJ Hartmann, D Burton, WB AF Blitz, L Spergel, DN Teuben, PJ Hartmann, D Burton, WB TI High-velocity clouds: Building blocks of the local group SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : kinematics and dynamics; intergalactic medium; Local Group ID LY-ALPHA FOREST; H-I CLOUDS; SEQUENCE-B-STARS; CHEMICAL EVOLUTION; NEUTRAL HYDROGEN; GALACTIC HALO; MILKY-WAY; ORION ASSOCIATION; MAGELLANIC STREAM; SENSITIVE SEARCH AB We suggest that the high-velocity clouds (HVCs) are large clouds, with typical diameters of 25 kpc, containing 3 x 10(7) M. of neutral gas and 3 x 10(8) M. of dark matter, falling onto the Local Group; altogether the HVCs contain 10(10) M. of neutral gas. Our reexamination of the Local Group hypothesis for the HVCs connects their properties to the hierarchical structure formation scenario and to the gas seen in absorption toward quasars. We show that at least one HVC complex (besides the Magellanic Stream) must be extragalactic at a distance of more than 40 kpc from the Galactic center, with a diameter greater than 20 kpc and a mass of more than 10(8) M.. We discuss a number of other clouds that are positionally associated with the Local Group galaxies, and we show that the entire ensemble of HVCs is inconsistent with a Galactic origin. The observed kinematics imply rather that the HVCs are falling toward the Local Group barycenter. We simulate the dynamical evolution of the Local Group and find that material falling onto the Local Group reproduces the location of two of the three most significant groupings of clouds and the kinematics of the entire cloud ensemble (excluding the Magellanic Stream). We interpret the third grouping (the A, C, and M complexes) as the nearest HVC. It is tidally unstable and is falling onto the Galactic disk. We interpret the more distant HVCs as gas contained within dark matter "minihalos" moving along filaments toward the Local Group. Most poor galaxy groups should contain similar H I clouds bound to the group at large distances from the individual galaxies. We suggest that the HVCs are local analogs of the Lyman limit absorbing clouds observed against distant quasars. Our picture implies that the chemical evolution of the Galactic disk is governed by episodic infall of metal-poor HVC gas that only slowly mixes with the rest of the interstellar medium. We argue that there is a Galactic fountain in the Milky Way, but that the fountain does not explain the origin of the HVCs. Our analysis of the H I data leads to the detection of a vertical infall of low-velocity gas toward the plane and implies that the H I disk is not in hydrostatic equilibrium. We suggest that the fountain is manifested mainly by relatively local neutral gas with characteristic velocities of 6 km s(-1) rather than 100 km s(-1). The Local Group infall hypothesis makes a number of testable predictions. The HVCs should have subsolar metallicities. Their Ha emission should be less than that seen from the Magellanic Stream. The clouds should not be seen in absorption against nearby stars. The clouds should be detectable in both emission and absorption around other galaxy groups. We show that current observations are consistent with these predictions and discuss future tests. C1 Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Maryland, College Pk, MD 20742 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Leiden Univ Observ, Leiden, Netherlands. RP Blitz, L (reprint author), Univ Calif Berkeley, Berkeley, CA 94720 USA. EM blitz@gmc.berkeley.edu; dns@astro.princeton.edu; teuben@astro.umd.edu; dap@abitibi.harvard.edu; burton@strw.leidenuniv.nl RI Spergel, David/A-4410-2011 NR 126 TC 354 Z9 357 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 1 PY 1999 VL 514 IS 2 BP 818 EP 843 DI 10.1086/306963 PN 1 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194ZQ UT WOS:000080225000025 ER PT J AU Finoguenov, A Jones, C Forman, W David, L AF Finoguenov, A Jones, C Forman, W David, L TI Stellar metallicities and SNIa rates in the early-type galaxy NGC 5846 from ROSAT and ASCA observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : abundances; galaxies : individual (NGC 5846); galaxies : stellar content; intergalactic medium; supernovae : general ID X-RAY-EMISSION; ELLIPTIC GALAXIES; INTRACLUSTER MEDIUM; PSPC OBSERVATIONS; HOT GAS; ABUNDANCES; NEARBY; GRADIENTS; CLUSTERS; WINDS AB In this paper we analyze the diffuse X-ray coronae surrounding the elliptical galaxy NGC 5846, combining measurements from two observatories, ROSAT and the Advanced Satellite for Cosmology and Astrophysics. We map the gas temperature distribution and find a central cool region within an approximately isothermal gas halo extending to a radius of about 50 kpc and evidence for a temperature decrease at larger radii. With a radially falling temperature profile, the total mass converges to (9.6 +/- 1.0) x 10(12) M. at similar to 230 kpc radius. This corresponds to a total mass to blue light ratio of 53 +/- 5 M./L.. As in other early type galaxies, the gas mass is only a few percent of the total mass. Using the spectroscopic measurements, we also derive radial distributions for the heavy elements silicon and iron and find that the abundances of both decrease with galaxy radius. The mass ratio of Si to Fe lies between the theoretical predictions for element production in SN Ia and SN II, suggesting an important role for SN Ia, as well as SN II, for gas enrichment in ellipticals. Using the SN Ia yield of Si, we set an upper limit of 0.012 h(50)(2) solar neutrino units (SNU) for the SN Ia rate at radii >50 kpc, which is independent of possible uncertainties in the iron L-shell modeling. We compare our observations with the theoretical predictions for the chemical evolution of ellipticals. We conclude that the metal content in stars, if explained by the star formation duration, requires a significant decline in the duration of star formation with galaxy radius, ranging from similar to 1 Gyr at the center to similar to 0.01 Gyr at 100 kpc radius. Alternatively, the decline in metallicity with galaxy radius may be caused by a similar drop with radius in the efficiency of star formation. Based on the Si and Fe measurements presented in this paper, we conclude that the latter scenario is preferred unless a dependence of the SN Ia rate on stellar metallicity is invoked. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Moscow Space Res Inst, Moscow 117810, Russia. RP Finoguenov, A (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 56 TC 15 Z9 15 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 1 PY 1999 VL 514 IS 2 BP 844 EP 855 DI 10.1086/306961 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194ZQ UT WOS:000080225000026 ER PT J AU Huchra, JP Vogeley, MS Geller, MJ AF Huchra, JP Vogeley, MS Geller, MJ TI The CfA Redshift Survey: Data for the south Galactic cap SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE galaxies : distances and redshifts; large-scale structure of universe; surveys ID PISCES-PERSEUS SUPERCLUSTER; SURFACE-BRIGHTNESS GALAXIES; NEUTRAL HYDROGEN OBSERVATIONS; EMISSION-LINE GALAXIES; GUIDE STAR CATALOG; 21 CM SURVEY; SPIRAL GALAXIES; RADIAL-VELOCITIES; X-RAY; COMPLETE SAMPLE AB We present redshifts for a sample of 4391 galaxies with magnitude m(B(0)) less than or equal to 15.5 covering 20(h) less than or equal to alpha less than or equal to 4(h) in right ascension and -2 degrees.5 less than or equal to delta less than or equal to 90 degrees in declination. This sample is complete for all galaxies in the merge of the Zwicky et al. and Nilson catalogs in the south Galactic cap. Redshifts for 2964 of these were measured as part of the second CfA Redshift Survey. The data reveal large voids in the foreground and background of the Perseus-Pisces Supercluster. The largest of these voids lies at a mean velocity similar to 8000 km s(-1), has diameter similar to 5000 km s(-1), and is enclosed by a complex of dense structures. The large structure known as the Perseus-Pisces Supercluster forms the near side of this complex. On the far side of this large void, at a mean velocity similar to 12,000 km s(-1), there is another coherent dense wall. The structures in this survey support the view that galaxies generally lie on surfaces surrounding or nearly surrounding low-density regions or voids. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. RP Huchra, JP (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 169 TC 152 Z9 152 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD APR PY 1999 VL 121 IS 2 BP 287 EP 368 DI 10.1086/313194 PG 82 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 212CZ UT WOS:000081199900001 ER PT J AU Acevedo-Rodriguez, P AF Acevedo-Rodriguez, P TI West Indian novelties I: a new species of Marsdenia (Asclepiadaceae) from Puerto Rico and a new name for a Jamaican species of Calyptranthes (Myrtaceae) SO BRITTONIA LA English DT Article DE Asclepiadaceae; Myrtaceae; Marsdenia; Calyptranthes; Puerto Rico; Jamaica; Greater Antilles; West Indies AB The new species Marsdenia woodburyana from southwestern Puerto Rico is described, illustrated, and contrasted to its putatively closest relative. The new name Calyptranthes proctorii is provided for the later homonym Calyptranthes uniflora Proctor. C1 Natl Museum Nat Hist, Smithsonian Inst, Dept Bot, Washington, DC 20560 USA. RP Acevedo-Rodriguez, P (reprint author), Natl Museum Nat Hist, Smithsonian Inst, Dept Bot, MRC-166, Washington, DC 20560 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU NEW YORK BOTANICAL GARDEN PI BRONX PA PUBLICATIONS DEPT, BRONX, NY 10458 USA SN 0007-196X J9 BRITTONIA JI Brittonia PD APR-JUN PY 1999 VL 51 IS 2 BP 166 EP 169 DI 10.2307/2666625 PG 4 WC Plant Sciences SC Plant Sciences GA 208VR UT WOS:000081013000008 ER PT J AU Erdmann, MV Caldwell, RL Jewett, SL Tjakrawidjaja, A AF Erdmann, MV Caldwell, RL Jewett, SL Tjakrawidjaja, A TI The second recorded living coelacanth from north Sulawesi SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE Latimeria chalumnae; Manado; Indonesia; gillnet; biogeography; morphometry ID LATIMERIA-CHALUMNAE AB A detailed account of the second coelacanth specimen known to have been captured in Indonesian waters is provided. The account is written in the official format of the Coelacanth Conservation Council's (CCC) inventory of known specimens of the living coelacanth Latimeria chalumnae, and the specimen is herein numbered CCC no. 175. Morphological measurements and fin ray counts are recorded. A comparison of these measurements and meristic data with those recorded for Comoran specimens of Latimeria chalumnae shows that the present specimen has a similar allometry to L. chalumnae. Ongoing genetic analyses should reveal the depth of divergence between the two known populations of living coelacanths and help determine if this specimen is conspecific with its Comoran counterparts. C1 Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. LIPI, Res & Dev Ctr Biol, Cibinong, Indonesia. RP Erdmann, MV (reprint author), Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. NR 13 TC 10 Z9 12 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD APR PY 1999 VL 54 IS 4 BP 445 EP 451 DI 10.1023/A:1007533629132 PG 7 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 217WQ UT WOS:000081522300009 ER PT J AU Stine, JK AF Stine, JK TI Explorations in environmental history. SO ENVIRONMENTAL HISTORY LA English DT Book Review C1 Smithsonian Inst, Amer Museum Nat Hist, Washington, DC 20560 USA. RP Stine, JK (reprint author), Smithsonian Inst, Amer Museum Nat Hist, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ENVIRONMENTAL HISTORY PI DURHAM PA 701 VICKERS AVE, DURHAM, NC 27701-3147 USA SN 1084-5453 J9 ENVIRON HIST JI Environ. Hist. PD APR PY 1999 VL 4 IS 2 BP 272 EP 273 DI 10.2307/3985308 PG 2 WC Environmental Studies; History SC Environmental Sciences & Ecology; History GA 212YM UT WOS:000081245300010 ER PT J AU Zotz, G Reichling, P Krack, S AF Zotz, G Reichling, P Krack, S TI Another woody hemiepiphyte with CAM: Havetiopsis flexilis SPRUCE ex PLANCH. et TR. (Clusiaceae) SO FLORA LA English DT Article DE crassulacean acid metabolism; hemiepiphytes; Barro Colorado Island; C-3-CAM intermediate; Clusiaceae ID CRASSULACEAN ACID METABOLISM; AFRA L JACQ; PORTULACARIA-AFRA; TROPICAL TREES; WATER-STRESS; GAS-EXCHANGE; MINOR L; LIGHT; ACCUMULATION; DROUGHT AB The discovery of crassulacean acid metabolism (CAM) in woody hemiepiphytes of the genus Clusia (Clusiaceae) has highly stimulated research on the physiology of these plants in the last decade, Our knowledge of the possible occurrence of CAM in other hemiepiphytic taxa, however, is still rather limited. The results of a recently published field study with Havetiopsis flexilis. member of another genus in the Clusiaceae, suggested that this species is an inducible CAM plant but lack of plant material had made a rigorous test of this notion impossible. The present communication presents conclusive evidence from a laboratory study under controlled conditions that drought indeed induces CAM in H. flexilis, i.e. leads to a net CO2 uptake at night associated with an increase in organic acids. The observed changes are fully reversible. This finding implies that at least three of the approximate 40 genera of woody hemiepiphytes have the capacity to use CAM. C1 Univ Wurzburg, Lehrstuhl Bot 2, Julius von Sachs Inst Biowissensch, D-97082 Wurzburg, Germany. Smithsonian Trop Res Inst, Panama City, Panama. RP Zotz, G (reprint author), Univ Wurzburg, Lehrstuhl Bot 2, Julius von Sachs Inst Biowissensch, Julius von Sachs Pl 3, D-97082 Wurzburg, Germany. NR 31 TC 2 Z9 2 U1 0 U2 1 PU URBAN & FISCHER VERLAG PI JENA PA BRANCH OFFICE JENA, P O BOX NO.100 537, D-07705 JENA, GERMANY SN 0367-2530 J9 FLORA JI Flora PD APR PY 1999 VL 194 IS 2 BP 215 EP 220 PG 6 WC Plant Sciences; Ecology SC Plant Sciences; Environmental Sciences & Ecology GA 186GZ UT WOS:000079721700008 ER PT J AU Winter, K Lovelock, CE AF Winter, K Lovelock, CE TI Growth responses of seedlings of early and late successional tropical forest trees to elevated atmospheric CO2 SO FLORA LA English DT Article DE elevated CO2; functional groups; growth; succession; tropical forest ID ECOSYSTEMS; PLANTS; CARBON AB Seedlings of nine tropical forest tree species were grown outdoors in open-top chambers at ambient and elevated (two times ambient) CO2 concentrations at the Smithsonian Tropical Research Institute, Republic of Panama. Plants were kept individually in large pots and received non-limiting supplies of water and mineral nutrients. The enhancement of biomass accumulation at elevated CO2 increased with increasing relative growth rates (RGR) of species at ambient CO2. Early successional pioneer trees (Cecropia longipes, Ficus insipida, Castilla elastica, Antirrhoea trichantha, Luehea seemannii, Pseudobombax septenatum) grew rapidly, and, at the end of 25 to 39 day treatments, dry matter accumulation was 74 +/- 26% higher at elevated than at ambient CO2 (mean increase +/- SD, n = 6). By contrast, seedlings of three late successional tree species (Calophyllum longifolium, Tetragastris panamensis, Virola surinamensis) grew slowly and, over an 84 day period, elevated CO2 led to either no (C. longifolium, T. panamensis) or only small enhancement in dry matter accumulation (V. surinamensis). These different responses to CO2 enrichment are a result of differences in growth kinetics between early and late successional species at ambient CO2 rather than a result of intrinsic physiological differences in CO2 responsiveness between plants from these two functional groups. C1 Smithsonian Trop Res Inst, Balboa, Panama. RP Winter, K (reprint author), Smithsonian Trop Res Inst, POB 2072, Balboa, Panama. RI Lovelock, Catherine/G-7370-2012 OI Lovelock, Catherine/0000-0002-2219-6855 NR 25 TC 16 Z9 17 U1 0 U2 7 PU ELSEVIER GMBH, URBAN & FISCHER VERLAG PI JENA PA OFFICE JENA, P O BOX 100537, 07705 JENA, GERMANY SN 0367-2530 EI 1618-0585 J9 FLORA JI Flora PD APR PY 1999 VL 194 IS 2 BP 221 EP 227 PG 7 WC Plant Sciences; Ecology SC Plant Sciences; Environmental Sciences & Ecology GA 186GZ UT WOS:000079721700009 ER PT J AU McCoy, TJ Wadhwa, M Keil, K AF McCoy, TJ Wadhwa, M Keil, K TI New lithologies in the Zagami meteorite: Evidence for fractional crystallization of a single magma unit on Mars SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID SHERGOTTITE METEORITES; SNC METEORITES; PETROGENESIS; MICROPROBE; MANTLE; WATER AB Zagami consists of a series of increasingly evolved magmatic lithologies. The bulk of the rock is a basaltic lithology dominated by pigeonite (FS28.7-54.3) augite (Fs(19.5-35.0)) and maskelynite (Ab(42-53)). Approximately 20 vol.% of Zagami is a basaltic lithology containing FeO-enriched pyroxene (pigeonite, Fs(27.0-80.8)) and mm- to cm-sized late-stage melt pockets. The melt pockets are highly enriched in olivine-bearing intergrowths, mesostases, phosphates (both whitlockite and water-bearing apatite), Fe,Ti-oxides and sulfides. The systematic increases in abundances of late-stage phases. Fs and incompatible element (e.g., Y and the REEs) contents of pigeonite, Ab contents of maskelynite. and FeO concentrations of whitlockite all point to a fractional crystallization sequence. The crystallization order in Zagami and the formation of these various lithologies was controlled by the abundances of iron, phosphorus, and calcium. During fractional crystallization, iron and phosphorus enrichment occurred, ultimately forcing the crystallization of calcium phosphates and olivine-bearing intergrowths The limited amount of calcium in the melt and its partitioning between phosphates and silicates controlled the crystallization of phosphates, plagioclase, pigeonite. and augite. The presence of these FeO-enriched, water-poor late-stage lithologies has important implications. Discrepancies between experimental and petrologic studies to infer the history of basaltic shergottites may be partially explained by the use of starting compositions which are too FeO-poor in the experimental studies. The water-poor nature of the late-stage melt pockets suggests crystallization from a very dry magma, although whether this magma was always dry or experienced significant near-surface degassing remains an open question. Finally, the presence of fractional crystallization products within Zagami suggests that this may be a relatively common process on Mars. Copyright (C) 1999 Elsevier Science Ltd. C1 Univ Hawaii Manoa, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Smithsonian Inst, Natl Museum Amer Hist, Dept Mineral Sci, Washington, DC 20560 USA. Washington Univ, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Field Museum Nat Hist, Dept Geol, Chicago, IL 60605 USA. Univ Hawaii, Hawaii Ctr Vulcanol, Honolulu, HI 96822 USA. RP McCoy, TJ (reprint author), Univ Hawaii Manoa, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. NR 25 TC 45 Z9 45 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD APR PY 1999 VL 63 IS 7-8 BP 1249 EP 1262 DI 10.1016/S0016-7037(99)00015-0 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 216FR UT WOS:000081431200021 ER PT J AU Bennett, RA Davis, JL Wernicke, BP AF Bennett, RA Davis, JL Wernicke, BP TI Present-day pattern of Cordilleran deformation in the western United States SO GEOLOGY LA English DT Article ID GLOBAL POSITIONING SYSTEM; BASE-LINE INTERFEROMETRY; NORTH-AMERICA MOTION; FAULT SLIP RATES; GPS MEASUREMENTS; RANGE PROVINCE; CALIFORNIA; NEVADA; CONSTRAINTS; KINEMATICS AB We present the first detailed geodetic image of the entire western United States south of lat 42 degrees N, merging both campaign and continuous Global Positioning System (GPS) and very long baseline interferometry (VLBI) data sets in a combined solution for station velocities having a single, uniform reference frame. The results are consistent with a number of features previously observed through local geodetic studies and very sparse space geodetic studies, including a dominant pattern of right-lateral shear associated with the San Andreas fault, rates of the westernmost sites (along the California coast) of 46-48 mm/yr relative to a North America reference frame, and some 11-13 mm/yr of deformation accommodated east of the Sierra Nevada in the Basin and Range province north of lat 36 degrees N, South of 36 degrees N, the solution also shows that the southernmost San Andreas fault system accommodates effectively all interplate motion and that the southern Basin and Range is not deforming significantly. At lat 37 degrees N, the eastern California shear zone appears to exhibit simple shear oriented between similar to N20 degrees W and similar to N40 degrees W relative to North America, with a fairly well defined transition zone from localized shear to diffuse spreading in the Basin and Range. Enigmatically, this transition involves a significant component of contraction normal to the overall shear-zone trend; sites in the Great Basin move southwestward at up to similar to 5 mm/yr toward sites within the eastern California shear zone. To the north, in contrast, there appears to be a relatively smooth transition from east-west spreading within the eastern Great Basin to northwest-southeast shear across the westernmost Basin and Range. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Pasadena, CA 91125 USA. RP Bennett, RA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Davis, James/D-8766-2013 OI Davis, James/0000-0003-3057-477X NR 26 TC 94 Z9 94 U1 1 U2 11 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD APR PY 1999 VL 27 IS 4 BP 371 EP 374 DI 10.1130/0091-7613(1999)027<0371:PDPOCD>2.3.CO;2 PG 4 WC Geology SC Geology GA 185LK UT WOS:000079670300021 ER PT J AU James, SH Keighery, GK Moorrees, A Waycott, M AF James, SH Keighery, GK Moorrees, A Waycott, M TI Genomic coalescence in a population of Laxmannia sessiliflora (Angiospermae, Anthericaceae): an association of lethal polymorphism, self-pollination and chromosome number reduction SO HEREDITY LA English DT Article DE chromosome polymorphism; dysploidy; genomic coalescence; Laxmannia; lethal polymorphism; self-pollination ID PIGEON ROCK POPULATION; COMPLEX HYBRIDITY; ISOTOMA-PETRAEA; CYTOEVOLUTION; PHYLOGENY; GENES AB A population of Laxmannia R. Br. (Angiospermae, Anthericaceae) near Collie, Western Australia, combines the taxonomically significant sessile inflorescences of L. sessiliflora Dcne. (n = 4) and the derived breeding system of L. ramosa Lindl. (n = 4). It exhibits a polymorphism for seed-aborting lethal equivalents, significant levels of self-pollination and a chromosome polymorphism in which a haploid genome with n = 3 is most frequent. Allozyme analysis indicates that the population is either of hybrid origin or one that has uniquely diverged from a phylogenetic link between the two species. The population is considered to represent a natural demonstration of the phenomenon of genomic coalescence as modelled by James (1992, Heredity, 68, 449-456) in which devices which reduce the number of independently segregating supergenes heterozygous for recessive lethals are elevated to high frequencies by inbreeding. The population also suggests a mechanism whereby dysploid chromosome number reduction may be promoted by natural selection in natural population systems. C1 Univ Western Australia, Dept Bot, Nedlands, WA 6907, Australia. RP Waycott, M (reprint author), Smithsonian Trop Res Inst, Balboa, Panama. NR 24 TC 5 Z9 5 U1 1 U2 6 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0018-067X J9 HEREDITY JI Heredity PD APR PY 1999 VL 82 BP 364 EP 372 DI 10.1038/sj.hdy.6884840 PN 4 PG 9 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 205TH UT WOS:000080836300003 ER PT J AU Kooistra, WHCF Calderon, M Hillis, LW AF Kooistra, WHCF Calderon, M Hillis, LW TI Development of the extant diversity in Halimeda is linked to vicariant events SO HYDROBIOLOGIA LA English DT Article; Proceedings Paper CT XVIth International Seaweed Symposium on the Seaweed Industry and Research and Development - A Solid Partnership CY 1998 CL CEBU, PHILIPPINES SP Dept Sci & Technol, Philippines, FMC Marine Colloids, Philippines, Genn Philippines Inc, Japan Seaweed Assoc, Marinalg Int, Natl Acad Sci & Technol, Shemberg Mkt Corp, SE Asian Fisheries Dev Ctr, Land Bank Philippines, MCPI Corp, Westmont Bank Philippines DE 18S rDNA; biogeography; Bryopsidales; evolution; Halimeda; phylogeny; Tethys; vicariance ID GREEN-ALGA-HALIMEDA; SEQUENCE DATA; PHOTOSYNTHESIS; CALCIFICATION; CHLOROPHYTA; PHYLOGENY; ECOLOGY; RECORD AB Partial 18S rDNA sequences, including a 102 base pair insertion, were used to infer a phylogeny among 48 samples across all sections in Halimeda Lamouroux, 1812. The phylogeny reveals a separation of the monophyletic section Rhipsalis into a western Atlantic and a western Pacific clade. Consequently, morphologically similar species within this section such as H. monile (Ellis & Solander) Lamouroux (western Atlantic), and H. cylindracea Decaisne (western Pacific), are not sister taxa. Vicariant events that separated the tropical regions of the Atlantic and Indo-Pacific Oceans can explain the observed biogeographical pattern in section Rhipsalis. C1 Smithsonian Trop Res Inst, Unit 0948, APO, AA 34002 USA. RP Hillis, LW (reprint author), 20 Brooks Rd, Woods Hole, MA 02543 USA. OI Kooistra, Wiebe/0000-0002-8641-9739 NR 32 TC 3 Z9 4 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD APR 1 PY 1999 VL 399 BP 39 EP 45 PG 7 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 237VH UT WOS:000082676900007 ER PT J AU Alcantara, LB Calumpong, HP Martinez-Goss, MR Menez, EG Israel, A AF Alcantara, LB Calumpong, HP Martinez-Goss, MR Menez, EG Israel, A TI Comparison of the performance of the agarophyte, Gracilariopsis bailinae, and the milkfish, Chanos chanos, in mono- and biculture SO HYDROBIOLOGIA LA English DT Article; Proceedings Paper CT XVIth International Seaweed Symposium on the Seaweed Industry and Research and Development - A Solid Partnership CY 1998 CL CEBU, PHILIPPINES SP Dept Sci & Technol, Philippines, FMC Marine Colloids, Philippines, Genn Philippines Inc, Japan Seaweed Assoc, Marinalg Int, Natl Acad Sci & Technol, Shemberg Mkt Corp, SE Asian Fisheries Dev Ctr, Land Bank Philippines, MCPI Corp, Westmont Bank Philippines DE biculture; Chanos; epiphytes; Gracilariopsis; Philippines; water quality ID SOUTHERN CHILE; RHODOPHYTA; CULTURE; GROWTH; CULTIVATION; EPIPHYTES; SEAWEEDS AB The performances of the agarophyte, Gracilariopsis bailinae, and the milkfish, Chanos chanos, under monoculture and biculture conditions in aquaria and ponds were studied from May 1997 to March 1998. Water quality of both systems was monitored. The two species have reciprocal characteristics in their biological requirements and byproducts. Both species attained higher growth rate in biculture: in aquaria Gracilariopsis obtained a mean daily growth rate of 4.72 +/- 1.64% for biculture and 3.44 +/- 2.74% in Gracilariopsis monoculture while Chanos had a mean daily growth rate of 4.81 +/- 2.13% in biculture and 4.13 +/- 2.13% in Chanos monoculture. In ponds, Gracilariopsis obtained a mean daily growth rate of 3.68 +/- 0.39% in biculture and 2.46 +/- 0.38% in Gracilariopsis monoculture while Chanos had a mean daily growth rate of 4.81 +/- 0.33% in biculture and 2.9 +/- 0.1% in Chanos monoculture. The growth rates for both Gracilariopsis and Chanos decreased weekly through one month of culture. Higher dissolved oxygen levels were observed in Gracilariopsis monoculture and in biculture and significantly lower in Chanos monoculture. Chanos did not control epiphytism in Gracilariopsis. There was no difference in epiphytism in either culture systems in aquaria, but a significant growth of green algae occurred in ponds with monoculture of Gracilariopsis. C1 Silliman Univ, Marine Lab, Dumaguete, Philippines. State Polytech Coll Palawan, Puerto Princesa 5300, Philippines. Univ Philippines Los Banos, IBS CAS, Laguna 4301, Philippines. Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. Natl Inst Oceanog, Israel Oceanog & Limnol Res, IL-31080 Haifa, Israel. RP Calumpong, HP (reprint author), Silliman Univ, Marine Lab, Dumaguete, Philippines. NR 21 TC 3 Z9 3 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD APR 1 PY 1999 VL 399 BP 443 EP 453 PG 11 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 237VH UT WOS:000082676900055 ER PT J AU Allison, DK AF Allison, DK TI History of computing: An encyclopedia of the people and machines that made computer history SO IEEE ANNALS OF THE HISTORY OF COMPUTING LA English DT Software Review C1 Smithsonian Inst, Natl Museum Amer Hist, Chair Informat Technol & Soc, Washington, DC 20560 USA. RP Allison, DK (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Chair Informat Technol & Soc, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1058-6180 J9 IEEE ANN HIST COMPUT JI IEEE Ann. Hist. Comput. PD APR-JUN PY 1999 VL 21 IS 2 BP 80 EP 80 PG 1 WC Computer Science, Theory & Methods; History & Philosophy Of Science SC Computer Science; History & Philosophy of Science GA 189ME UT WOS:000079908200015 ER PT J AU Kudoh, H Shibaike, H Takasu, H Whigham, DF Kawano, S AF Kudoh, H Shibaike, H Takasu, H Whigham, DF Kawano, S TI Genet structure and determinants of clonal structure in a temperate deciduous woodland herb, Uvularia perfoliata SO JOURNAL OF ECOLOGY LA English DT Article DE clonal diversity; gap; genet structure; genetic variation; ramet; spatial structure; Uvularia perfoliata ID TRIFOLIUM-REPENS L; PLANT-POPULATIONS; SPATIAL AUTOCORRELATION; SIZE HIERARCHIES; LIFE-HISTORY; DIVERSITY; DYNAMICS; BIOLOGY; PATTERNS; GROWTH AB 1 We used isozyme variation to examine the genet structure of Uvularia perfoliata patches in gap and closed canopy habitats in a temperate deciduous forest in Maryland, USA. 2 A large patch in a gap habitat was composed of a small number of widely spread genets with many ramets, and a large number of genets with more restricted distribution and few ramets, Genets with many ramets were patchily distributed at a metre scale. Analysis of genet structure on a scale of square centimetres, however, revealed that the genets were highly intermingled with no clear boundaries between them. The presence at both scales of sampling of many genets with unique multilocus genotypes indicated continuing genet recruitment within the population. 3 In the closed canopy habitat, the patches examined were each composed of a single unique multilocus genotype, suggesting that each had developed by asexual propagation following the establishment of a single genet. 4 The clonal structure of U. perfoliata patches in both gap and closed canopy habitats therefore appears to depend on recruitment patterns of genets. Populations in closed canopy habitats are characterized by a 'waiting' strategy, in which asexual ramet production maintains populations until genet recruitment by seed production can occur under the more optimal conditions associated with canopy gaps. Extended sampling suggests that the genetic diversity of U. perfoliata populations is primarily controlled by the disturbance regime of the forest canopy. C1 Kyoto Univ, Grad Sch Sci, Dept Bot, Kyoto 6068502, Japan. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Wakayama Univ, Coll Educ, Dept Biol, Wakayama 6408441, Japan. RP Kyoto Univ, Grad Sch Sci, Dept Bot, Kyoto 6068502, Japan. OI Whigham, Dennis/0000-0003-1488-820X NR 69 TC 89 Z9 97 U1 0 U2 13 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0022-0477 EI 1365-2745 J9 J ECOL JI J. Ecol. PD APR PY 1999 VL 87 IS 2 BP 244 EP 257 DI 10.1046/j.1365-2745.1999.00355.x PG 14 WC Plant Sciences; Ecology SC Plant Sciences; Environmental Sciences & Ecology GA 193XH UT WOS:000080162700006 ER PT J AU de Blois, ST Novak, MA Bond, M AF de Blois, ST Novak, MA Bond, M TI Can memory requirements account for species' differences in invisible displacement tasks? SO JOURNAL OF EXPERIMENTAL PSYCHOLOGY-ANIMAL BEHAVIOR PROCESSES LA English DT Article ID PIAGETIAN OBJECT-PERMANENCE; DOGS CANIS-FAMILIARIS; CATS FELIS-CATUS; SEARCH BEHAVIOR; MONKEYS; COGNITION; GORILLA; INFANTS AB We tested the hypothesis that poor performance on the Piagetian invisible displacement task is related to increased memory requirements. Rhesus monkeys and orangutans received 3 types of problems (invisible, visible, and no transfer problems) each containing a number of steps equivalent to that of standard invisible displacements. if failure to solve invisible displacements was due to increased memory requirements, then the primates should perform at chance level on all 3 problems. However, rhesus monkeys solved visible and no transfer problems, but not invisible transfer problems. Half of the orangutans solved all 3 transfer problems, although their performance on invisible transfer problems was lower than that on the other problems. A subsequent cuing phase led to improved performance, and a few monkeys solved invisible transfer problems. C1 Univ Massachusetts, Dept Psychol, Amherst, MA 01003 USA. Smithsonian Inst, Primate Unit, Washington, DC 20560 USA. RP de Blois, ST (reprint author), Univ Denver, Dept Psychol, Frontier Hall, Denver, CO 80208 USA. NR 24 TC 21 Z9 22 U1 1 U2 7 PU AMER PSYCHOLOGICAL ASSOC PI WASHINGTON PA 750 FIRST ST NE, WASHINGTON, DC 20002-4242 USA SN 0097-7403 J9 J EXP PSYCHOL ANIM B JI J. Exp. Psychol.-Anim. Behav. Process. PD APR PY 1999 VL 25 IS 2 BP 168 EP 176 DI 10.1037//0097-7403.25.2.168 PG 9 WC Psychology, Biological; Behavioral Sciences; Psychology; Psychology, Experimental; Zoology SC Psychology; Behavioral Sciences; Zoology GA 183GL UT WOS:000079545800003 PM 10331917 ER PT J AU Bobe, R Behrensmeyer, AK AF Bobe, R Behrensmeyer, AK TI Environmental changes in early hominid evolution derived from analysis of fossil mammals from the lower Omo Valley, Ethiopia SO JOURNAL OF HUMAN EVOLUTION LA English DT Meeting Abstract C1 Smithsonian Inst, Dept Paleobiol, ETE Program, NHB MRC 121, Washington, DC 20560 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0047-2484 J9 J HUM EVOL JI J. Hum. Evol. PD APR PY 1999 VL 36 IS 4 BP A3 EP A3 PG 1 WC Anthropology; Evolutionary Biology SC Anthropology; Evolutionary Biology GA 186YJ UT WOS:000079758600009 ER PT J AU Potts, R Behrensmeyer, AK Ditchfield, P AF Potts, R Behrensmeyer, AK Ditchfield, P TI Hominid responses to Pleistocene paleolandscapes, Olorgesailie Formation, Kenya SO JOURNAL OF HUMAN EVOLUTION LA English DT Meeting Abstract C1 Smithsonian Inst, Museum Natl Hist Nat, Human Origins Program, Washington, DC 20560 USA. Univ Bristol, Dept Geol, Bristol BS8 1RJ, Avon, England. NR 0 TC 0 Z9 0 U1 0 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0047-2484 J9 J HUM EVOL JI J. Hum. Evol. PD APR PY 1999 VL 36 IS 4 BP A18 EP A19 PG 2 WC Anthropology; Evolutionary Biology SC Anthropology; Evolutionary Biology GA 186YJ UT WOS:000079758600033 ER PT J AU Hacker, BC AF Hacker, BC TI The role of federal military forces in domestic disorders, 1877-1945 SO JOURNAL OF MILITARY HISTORY LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Hacker, BC (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SOC MILITARY HISTORY PI LEXINGTON PA C/O VIRGINIA MILITARY INST, GEORGE C MARSHALL LIBRARY, LEXINGTON, VA 24450-1600 USA SN 0899-3718 J9 J MILITARY HIST JI J. Mil. Hist. PD APR PY 1999 VL 63 IS 2 BP 452 EP 453 DI 10.2307/120669 PG 2 WC History SC History GA 183HA UT WOS:000079547100025 ER PT J AU Langley, HD AF Langley, HD TI Naval surgeon: Life and death at sea in the age of sail. SO JOURNAL OF THE HISTORY OF MEDICINE AND ALLIED SCIENCES LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Langley, HD (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-5045 J9 J HIST MED ALL SCI JI J. Hist. Med. Allied Sci. PD APR PY 1999 VL 54 IS 2 BP 333 EP 334 PG 2 WC Health Care Sciences & Services; History & Philosophy Of Science SC Health Care Sciences & Services; History & Philosophy of Science GA 201WR UT WOS:000080620300015 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI Common man, mythic vision: The paintings of Ben Shahn. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC 20560 USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Lib, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD APR 1 PY 1999 VL 124 IS 6 BP 90 EP 90 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 180RB UT WOS:000079398000055 ER PT J AU Riley, SM AF Riley, SM TI The Queen's bastard. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC 20560 USA. RP Riley, SM (reprint author), Smithsonian Inst Lib, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD APR 1 PY 1999 VL 124 IS 6 BP 129 EP 129 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 180RB UT WOS:000079398000251 ER PT J AU Fritz, JJ AF Fritz, JJ TI Carbon fixation and coccolith detachment in the coccolithophore Emiliania huxleyi in nitrate-limited cyclostats SO MARINE BIOLOGY LA English DT Article ID INORGANIC CARBON; STEADY-STATE; MARINE-PHYTOPLANKTON; CHEMICAL-COMPOSITION; CONTINUOUS-CULTURE; ATLANTIC-OCEAN; LIGHT; CALCIFICATION; PRYMNESIOPHYCEAE; LOHMANN AB This study addresses carbon fixation and coccolith production and detachment in the cosmopolitan species Emiliania huxleyi (Lohmann) Hay et Mohler, under conditions of nitrate limitation and high light typical of surface water in the ocean. Cells were grown under controlled growth conditions using nitrate-limited cyclostat cultures at four growth rates between 0.2 and 0.7 d(-1) in 1995. Both photosynthesis and calcification rates increased with growth rate. Coccolith dimensions remained constant at all cell growth rates. Specific rates of coccolith detachment also increased linearly with cell-specific growth rate at a ratio not significantly different from 1.00. Estimates of coccolith carbon content decreased with increasing cell growth rates. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RP Fritz, JJ (reprint author), Smithsonian Environm Res Ctr, 247 Contees Wharf Rd, Edgewater, MD 21401 USA. NR 47 TC 24 Z9 26 U1 0 U2 9 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD APR PY 1999 VL 133 IS 3 BP 509 EP 518 DI 10.1007/s002270050491 PG 10 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 189DJ UT WOS:000079888600015 ER PT J AU Walker, JL Potter, CW Macko, SA AF Walker, JL Potter, CW Macko, SA TI The diets of modern and historic bottlenose dolphin populations reflected through stable isotopes SO MARINE MAMMAL SCIENCE LA English DT Article DE bottlenose dolphin; Tursiops truncatus; carbon isotopes; nitrogen isotopes; diet ID CARBON ISOTOPES; NORTH-ATLANTIC; FRESH-WATER; AMINO-ACIDS; NITROGEN; FRACTIONATION; MARINE; BONE; DELTA-C-13; ANIMALS AB The delta(13)C and delta(15)N compositions of teeth used in combination with existing data provide dietary information for different populations of western North Atlantic bottlenose dolphins (Tursiops truncatus.). The dental isotopic signatures of bottlenose dolphins collected during the 1980s significantly differ for coastal and offshore ecotypes and are consistent with reports that coastal forms feed primarily on fish whereas offshore individuals consume more squid. In a second study, the isotopic compositions of teeth from bottlenose dolphins that span a 100-yr period and data from published stomach content analyses as well as field observations made during the past 100 yr provide evidence that coastal bottlenose dolphins from the 1880s, 1920s, and 1980s had similar diets. C1 Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA. Smithsonian Inst, Marine Mammal Program, Washington, DC 20560 USA. Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA. RP Walker, JL (reprint author), Univ Virginia, Dept Environm Sci, Clark Hall, Charlottesville, VA 22903 USA. NR 43 TC 42 Z9 43 U1 5 U2 17 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD APR PY 1999 VL 15 IS 2 BP 335 EP 350 DI 10.1111/j.1748-7692.1999.tb00805.x PG 16 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 188AH UT WOS:000079821000003 ER PT J AU Galama, TJ Briggs, MS Wijers, RAMJ Vreeswijk, PM Rol, E Band, D van Paradijs, J Kouveliotou, C Preece, RD Bremer, M Smith, IA Tilanus, RPJ de Bruyn, AG Strom, RG Pooley, G Castro-Tirado, AJ Tanvir, N Robinson, C Hurley, K Heise, J Telting, J Rutten, RGM Packham, C Swaters, R Davies, JK Fassia, A Green, SF Foster, MJ Sagar, R Pandey, AK Nilakshi Yadav, RKS Ofek, EO Leibowitz, E Ibbetson, P Rhoads, J Falco, E Petry, C Impey, C Geballe, TR Bhattacharya, D AF Galama, TJ Briggs, MS Wijers, RAMJ Vreeswijk, PM Rol, E Band, D van Paradijs, J Kouveliotou, C Preece, RD Bremer, M Smith, IA Tilanus, RPJ de Bruyn, AG Strom, RG Pooley, G Castro-Tirado, AJ Tanvir, N Robinson, C Hurley, K Heise, J Telting, J Rutten, RGM Packham, C Swaters, R Davies, JK Fassia, A Green, SF Foster, MJ Sagar, R Pandey, AK Nilakshi Yadav, RKS Ofek, EO Leibowitz, E Ibbetson, P Rhoads, J Falco, E Petry, C Impey, C Geballe, TR Bhattacharya, D TI The effect of magnetic fields on gamma-ray bursts inferred from multi-wavelength observations of the burst of 23 January 1999 SO NATURE LA English DT Article ID BATSE OBSERVATIONS; RADIO TELESCOPE; PHOTOMETRY; AFTERGLOW; SPECTRA AB Gamma-ray bursts (GRBs) are thought to arise when an extremely relativistic outflow of particles from a massive explosion (the nature of which is still unclear) Interacts with material surrounding the site of the explosion. observations of the evolving changes in emission at many wavelengths allow us to Investigate the origin of the photons, and so potentially determine the nature of the explosion. Here we report the results of gamma-ray, optical, Infrared, submillimetre, millimetre and radio observations of the burst GRB990123 and Its afterglow. Our Interpretation of the data Indicates that the initial and afterglow emissions are associated with three distinct regions In the fireball. The peak flux of the afterglow, one day after the burst, has a lower frequency than observed for other bursts; this explains tbe short-lived radio emission. We suggest that the differences between bursts reflect variations In the magnetic-field strength in the afterglow-emitting regions. C1 Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Univ Calif San Diego, CASS, La Jolla, CA 92093 USA. NASA, MSFC, Huntsville, AL 35812 USA. Univ Space Res Assoc, Huntsville, AL 35812 USA. Inst Radio Astron Millimetr, F-38406 St Martin Dheres, France. Rice Univ, Dept Space Phys & Astron, Houston, TX 77005 USA. Joint Astron Ctr, Hilo, HI 96720 USA. Netherlands Fdn Res Astron, NL-7990 AA Dwingeloo, Netherlands. Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. Univ Cambridge, Cavendish Lab, Mullard Radio Astron Observ, Cambridge CB3 0HE, England. Lab Astrofis Espacial & Fis Fundamental, INTA, E-28080 Madrid, Spain. CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Hertfordshire, Dept Phys Sci, Hatfield AL10 9AB, Herts, England. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Natl Sci Fdn, Berkeley, CA 94720 USA. SRON, Space Res Lab, NL-3584 CA Utrecht, Netherlands. Isaac Newton Grp, E-38780 Santa Cruz De La Palma, Islas Canarias, Spain. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2BZ, England. Univ Kent, Phys Lab, Sch Phys Sci, Unit Space Sci & Astrophys, Canterbury CT2 7NR, Kent, England. Uttar Pradesh State Observ, Naini Tal 263129, India. Tel Aviv Univ, Wise Observ, IL-69978 Tel Aviv, Israel. Kitt Peak Natl Observ, Tucson, AZ 85726 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Arizona, Steward Observ, Tucson, AZ 85719 USA. Univ Hawaii, Gemini Observ, Hilo, HI 96720 USA. Raman Res Inst, Bangalore 560080, Karnataka, India. RP Galama, TJ (reprint author), Univ Amsterdam, Astron Inst Anton Pannekoek, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. EM titus@astro.uva.nl RI Green, Simon/C-7408-2009; Galama, Titus/D-1429-2014; Bhattacharya, Dipankar/J-6927-2015; OI Galama, Titus/0000-0002-1036-396X; Bhattacharya, Dipankar/0000-0003-3352-3142; Castro-Tirado, A. J./0000-0003-2999-3563 NR 49 TC 139 Z9 141 U1 0 U2 4 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD APR 1 PY 1999 VL 398 IS 6726 BP 394 EP 399 DI 10.1038/18828 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 182PW UT WOS:000079508200043 ER PT J AU Jorge, LF Eichelbaum, M Griese, EU Inaba, T Arias, TD AF Jorge, LF Eichelbaum, M Griese, EU Inaba, T Arias, TD TI Comparative evolutionary pharmacogenetics of CYP2D6 in Ngawbe and Embera Amerindians of Panama and Colombia: role of selection versus drift in world populations SO PHARMACOGENETICS LA English DT Article DE CYP2D6; sparteine; Amerindians; evolution; diet ID LOWER CENTRAL-AMERICA; HLA-B ALLELES; CYTOCHROME-P450 CYP2D6; GENETIC-POLYMORPHISM; POOR METABOLIZERS; ZIMBABWEAN POPULATION; EUROPEAN POPULATION; GUAYMI AMERINDIANS; SWEDISH POPULATION; MITOCHONDRIAL-DNA AB The development of CYP2D6 has been attributed to the need of earth-dwelling animals to detoxify toxic xenobiotics (phytoalexins) present in plants. This hypothesis has been extrapolated to humans, but is yet unconfirmed. Therefore, we studied two Amerindian populations as the best available model to test the effect of selection through diet on human CYP2D6 evolution. The frequency of sparteine poor metabolizers in Ngawbe was 4.4% (n = 344), while the frequency in Embera was 2.2% (n = 153). Among Ngawbe and Embera, CYP2D6*4 (allelic frequencies for each tribe, respectively: 0.171; 0.14), CYP2D6*6 (0.005; 0.011) and CYP2D6*10 (0.175; 0.069) were detected, while CYP2D6*3, CYP2D6*5, CYP2D6*9 and CYP2D6*16 were absent. All poor metabolizers possessed either CYP2D6*4 or CYP2D6*6 and there were no disagreements between genotypic and phenotypic data. The total frequency of mutant alleles showed no difference among Amerindians or when compared to Caucasians. It was higher than in Chinese, since the frequency of CYP2D6*4 was higher in Amerindians. XbaI restriction fragment length polymorphisms haplotypes were very homogeneous in Amerindians, because the only fragment that hybridized with the CYP2D6 cDNA probe was the 29 kb (not 42/44 kb or 11.5/13 kb). This indicated no gene cluster recombinations that generate insertions or deletions. We propose that in earlier hominids and humans, CYP2D6 had increasingly become a vestigial characteristic unconstrained by dietary stressors, as a result of cultural survival strategies. Human CYP2D6 evolution was preferentially affected by random genetic drift, and not by adaptive or purifying selection. Pharmacogenetics 9:217-228 (C) 1999 Lippincott Williams & Wilkins. C1 Univ Panama, DNA & Human Genom Inst, Panama City, Panama. Univ Panama, Coll Pharm, Panama City, Panama. Dr Margarete Fischer Bosch Inst Clin Pharmacol, D-7000 Stuttgart, Germany. Univ Toronto, Dept Pharmacol, Toronto, ON, Canada. Smithsonian Trop Res Inst, Panama City, Panama. RP Arias, TD (reprint author), Apartado 10-909,Estafeta Univ, Panama City, Panama. NR 78 TC 36 Z9 39 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0960-314X J9 PHARMACOGENETICS JI Pharmacogenetics PD APR PY 1999 VL 9 IS 2 BP 217 EP 228 PG 12 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Pharmacology & Pharmacy SC Biotechnology & Applied Microbiology; Genetics & Heredity; Pharmacology & Pharmacy GA 216CB UT WOS:000081422000010 PM 10376769 ER PT J AU Holzmann, M Krauth, W Naraschewski, M AF Holzmann, M Krauth, W Naraschewski, M TI Precision Monte Carlo test of the Hartree-Fock approximation for a trapped Bose gas SO PHYSICAL REVIEW A LA English DT Article ID EINSTEIN CONDENSATION; CRITICAL-TEMPERATURE; FINITE-TEMPERATURE; FIELD AB We compare the semiclassical Hartree-Fock approximation for a trapped Bose gas to a direct path-integral quantum Monte Carlo simulation. The chosen parameters correspond to current Rb-87 experiments. We observe corrections to the mean-field density profile: the path-integral calculation reveals an increase of the number of condensed particles, which is of the same order as a previously computed result for a homogeneous system. We discuss the experimental observability of the effect and propose a method to analyze data of in situ experiments. [S1050-2947(99)02404-X]. C1 Ecole Normale Super, CNRS, Lab Phys Stat, F-75231 Paris 05, France. Ecole Normale Super, Lab Kastler Brossel, F-75231 Paris, France. Harvard Univ, Dept Phys, Jefferson Lab, Cambridge, MA 02138 USA. Harvard Univ, Harvard Smithsonian Ctr Astrophys, ITAMP, Cambridge, MA 02138 USA. RP Holzmann, M (reprint author), Ecole Normale Super, CNRS, Lab Phys Stat, 24 Rue Lhomond, F-75231 Paris 05, France. RI Krauth, Werner/L-5623-2016 OI Krauth, Werner/0000-0003-0183-6726 NR 27 TC 59 Z9 60 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1999 VL 59 IS 4 BP 2956 EP 2961 DI 10.1103/PhysRevA.59.2956 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 184JT UT WOS:000079609100059 ER PT J AU Jack, MW Naraschewski, M Collett, MJ Walls, DF AF Jack, MW Naraschewski, M Collett, MJ Walls, DF TI Markov approximation for the atomic output coupler SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; MASTER EQUATION; PHASE DIFFUSION; LASER; SAMPLES; INPUT; TRAP AB The regions of validity of the Markov approximation for the coupling of atoms out of an atomic trap rut determined. We consider radio-frequency output coupling in the presence of gravity and collisional repulsion, and Raman output coupling. The Markov approximation is crucial in most theoretical descriptions of an atom laser that assume a continuous process of output coupling from a trapped Bose-Einstein condensate. In this regime many techniques that have proved to be useful for modeling the optical laser, such as master equations, can be used to describe the dynamics of the damping of the condensate mode undergoing output coupling. [S1050-2947(99)04904-5]. C1 Univ Auckland, Dept Phys, Auckland, New Zealand. Harvard Univ, Dept Phys, Jefferson Lab, Cambridge, MA 02138 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Jack, MW (reprint author), Univ Auckland, Dept Phys, Private Bag 92019, Auckland, New Zealand. RI Collett, Matthew/B-4762-2010 NR 30 TC 24 Z9 24 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1999 VL 59 IS 4 BP 2962 EP 2973 DI 10.1103/PhysRevA.59.2962 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 184JT UT WOS:000079609100060 ER PT J AU Gagne, RJ Lill, JT AF Gagne, RJ Lill, JT TI A new nearctic species of Lestodiplosis (Diptera : Cecidomyiidae) preying on an oak leaf tier, Psilocorsis quercicella (Lepidoptera : Oecophoridae) SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE Lestodiplosis; predator; oak leaf tier AB A new species of cecidomyiid, Lestodiplosis venusta Gagne, is described, illustrated, and compared to its most similar congeners. Larvae of the new species were found in Missouri preying on caterpillars of Psilocorsis quercicella Clemens, a leaf skeletonizer of oaks. An unidentified species of Ceraphronidae was reared from pupae of the Lestodiplosis. C1 Natl Museum Nat Hist, Smithsonian Inst, ARS,Systemat Entomol Lab, PSI,USDA, Washington, DC 20560 USA. RP Gagne, RJ (reprint author), Natl Museum Nat Hist, Smithsonian Inst, ARS,Systemat Entomol Lab, PSI,USDA, Washington, DC 20560 USA. RI Lill, John/A-7935-2009 NR 4 TC 4 Z9 5 U1 1 U2 2 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD APR PY 1999 VL 101 IS 2 BP 332 EP 336 PG 5 WC Entomology SC Entomology GA 195BH UT WOS:000080228900014 ER PT J AU Mathis, WN AF Mathis, WN TI A review of the beach-fly genus Isocanace mathis (Diptera : Canacidae) SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE review; Diptera; Canacidae; beach flies; Isocanace; I-crosbyi; I-freidbergi; Old World AB The species of the beach-fly genus Isocanace Mathis are reviewed, including the description of two new species: I. crosbyi (New Zealand. South Island. NN: Cable Bay (41 degrees 09.6'S, 173 degrees 24.9'E) and I. freidbergi (Kenya. Takaungu (50 km N of Mombasa)). Descriptions for the genus and two species groups are also revised. C1 Smithsonian Inst, Dept Entomol, Washington, DC 20560 USA. RP Mathis, WN (reprint author), Smithsonian Inst, Dept Entomol, NHB 169, Washington, DC 20560 USA. NR 16 TC 1 Z9 1 U1 0 U2 1 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD APR PY 1999 VL 101 IS 2 BP 347 EP 358 PG 12 WC Entomology SC Entomology GA 195BH UT WOS:000080228900016 ER PT J AU Adamski, D AF Adamski, D TI Two neotropical Hypatopa Walsingham (Gelechioidea : Coleophoridae : Blastobasinae) with retractile labial palpi: A previously unknown Lepidopteran feature SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE retractile labial palpi; Blastobasini; Dominica; Grenada; West Indies AB Hypatopa cryptopalpella, n. sp., is described and H. brevipalpella Walsingham, 1897, is redescribed. Males of both species possess retractile labial palpi, a feature not known to occur elsewhere in Lepidoptera. Male sex scales on the distal segment of the labial palpi are associated with a deep invaginated pocket from the lower end of the frontoclypeus, extending within the head cavity to the area between the bases of the antennae. The invaginated pocket is filled with a copius brown mass that is believed to be a secretion deseminated by the male sex scales on the labial palpi. The location of the glandular cells cannot be identified until specimens suitable for histological sectioning become available. A lectotype is designated for Auximobasis brevipalpella Walsingham, 1897, and it is herein transferred to Hypatopa Walsingham, 1907 (new combination). C1 Smithsonian Inst, Dept Entomol, Washington, DC 20560 USA. RP Adamski, D (reprint author), Smithsonian Inst, Dept Entomol, NHB 169, Washington, DC 20560 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD APR PY 1999 VL 101 IS 2 BP 438 EP 448 PG 11 WC Entomology SC Entomology GA 195BH UT WOS:000080228900025 ER PT J AU Falco, EE Kurtz, MJ Geller, MJ Huchra, JP Peters, J Berlind, F Mink, DJ Tokarz, SP Ewell, B AF Falco, EE Kurtz, MJ Geller, MJ Huchra, JP Peters, J Berlind, F Mink, DJ Tokarz, SP Ewell, B TI The updated Zwicky Catalog (UZC) SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Review ID PISCES-PERSEUS SUPERCLUSTER; SURFACE-BRIGHTNESS GALAXIES; LARGE-SCALE STRUCTURE; CFA REDSHIFT SURVEY; NEUTRAL HYDROGEN OBSERVATIONS; EMISSION-LINE GALAXIES; VIRGO CLUSTER AREA; H-I OBSERVATIONS; TULLY-FISHER OBSERVATIONS; LOCAL CONVERGENCE DEPTH AB The Zwicky Catalog of galaxies (ZC), with m(Zw) less than or equal to 15.5, has been the basis for the Center for Astrophysics (CfA) redshift surveys. To date, analyses of the ZC and redshift surveys based on it have relied on heterogeneous sets of galaxy coordinates and redshifts. Here we correct some of the inadequacies of previous catalogs by providing (1) coordinates with less than or similar to 2 " errors for all of the 19,369 catalog galaxies, (2) homogeneously estimated redshifts for the majority (98%) of the data taken at the CfA (14,632 spectral, and (3) an estimate of the remaining "blunder" rate for both the CfA redshifts and for those compiled from the literature. For the reanalyzed CfA data we include a calibrated, uniformly determined error and an indication of the presence of emission lines in each spectrum.,We provide redshifts for 7257 galaxies in the CfA2 redshift survey not previously published; for another 5625 CfA redshifts we list the remeasured or uniformly rereduced value. Among our new measurements, 1807 are members of UZC "multiplets" associated with the original Zwicky catalog position in the coordinate range where the catalog is 98% complete. These multiplets provide new candidates for examination of tidal interactions among galaxies. All of the new redshifts correspond to UZC galaxies with properties recorded in the CfA redshift compilation known as ZCAT. About 1000 of our new measurements were motivated either by inadequate signal-to-noise in the original spectrum or by an: ambiguous identification of the galaxy associated with a ZCAT redshift. The redshift catalog we include here is similar to 96% complete to m(Zw) less than or equal to 15.5 and similar to 98% complete (12,925 galaxies out of a total of 13,150) for the right ascension ranges 20(h) greater than or equal to alpha(1950) less than or equal to 14(h) and 8(h) greater than or equal to alpha(1950) less than or equal to 17(h) and declination range -2.degrees 5 less than or equal to delta(1950) greater than or equal to 50 degrees. This more complete region includes all of the CfA2 survey as analyzed to date. The Great Wall structure persists throughout the northern survey region. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Falco, EE (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI KURTZ, Michael /B-3890-2009; OI Kurtz, Michael/0000-0002-6949-0090 NR 310 TC 314 Z9 316 U1 0 U2 3 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD APR PY 1999 VL 111 IS 758 BP 438 EP 452 DI 10.1086/316343 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189XW UT WOS:000079932300002 ER PT J AU Nowicke, JW Takahashi, M Webster, GL AF Nowicke, JW Takahashi, M Webster, GL TI Pollen morphology, exine structure and systematics of Acalyphoideae (Euphorbiaceae) - Part 2. Tribes Agrostistachydeae (Agrostistachys, Pseudagrostistachys, Cyttaranthus, Chondrostylis), Chrozophoreae (Speranskia, Caperonia, Philyra, Ditaxis, Argythamnia, Chiropetalum, Doryxylon, Sumbaviopsis, Thyrsanthera, Melanolepis, Chrozophora), Caryodendreae (Caryodendron, Discoglypremna, Alchorneopsis), Bernardieae (Bernardia, Necepsia, Paranecepsia, Discocleidion, Adenophaedra) and Pycnocomeae (Pycnocoma, Drocelonica, Argomuellera, Blumeodendron, Podadenia, Ptychopyxis, Botryophora) SO REVIEW OF PALAEOBOTANY AND PALYNOLOGY LA English DT Article DE pollen morphology; Euphorbiaceae; Acalyphoideae; exine structure; systematics ID CROTONOIDEAE AB This is the second paper of an extensive study of pollen morphology and exine structure of Acalyphoideae (Euphorbiaceae) following the most recent system of Webster. Part 2 describes the pollen of 30 genera assigned to tribes Agrostistachydeae, Chrozophoreae, Caryodendreae, Bernardieae and Pycnocomeae. In Agrostistachydeae, members of Agrostistachys and Pseudagrostistachys have similar but unspecialized pollen; grains of Cyttaranthus have weakly suprareticulate tecta of widely varying thickness and small densely spaced columellae; pollen of Chondrostylis has a croton sculpture and precisely defined bridges of ectexine over the endoaperture. Of the II genera assigned to tribe Chrozophoreae, pollen of Caperonia has prominent opercula, thick exines and punctate tecta, pollen of Ditaxis and Argythamnia is colpate, has large columellae, and the unevenly thick and complete tecta associated with suprareticulate sculpture or derivations thereof, and pollen of Chiropetalum has operculate apertures, diminutive columellae, and an incomplete finely reticulate tectum, characteristics which argue against a supposedly close relationship to Ditaxis and Argythamnia. Three of the four genera assigned to subtribe Doryxylinae, Doryxylon, Sumbaviopsis, and Melanolepis have similar pollen - thin exines with irregular foot layers, and irregular short columellae, whereas pollen of the fourth genus, Thyrsanthera, has thicker exines with a well-defined foot layer and more elongate columellae. The eight examined species of Chrozophora have 6-9 aperturate pollen and robust exines; two species have punctate tecta and zonorate endoapertures; the remaining species have heterobrochate tecta and lolongate endoapertures. The three genera comprising Caryodendreae, Caryodendron, Discoglypremna and Alchorneopsis, have small 3-colporate pollen with punctate tecta. Pollen of the five genera assigned to tribe Bernardieae, Bernardia, Necepsia, Paranecepsia, Discocleidion and Adenophaedra is of a similar, but unspecialized type - a punctate, deeply punctate, or microreticulate tectum, small endoaperture, and usually a prominent margo. The present concept of tribe Pycnocomeae as comprising Pycnocoma, Droceloncia, Algomuellera, Blumeodendron, Podadenia, Ptychopyxis and Botryophora is not supported by the pollen data. Members of Pycnocoma have pollen with a derived exine structure - a conspicuously thick endexine throughout the grain, threadlike foot layers, and columellae reduced to a point on the proximal side of the tectal elements. The pollen data are somewhat ambiguous about a close relationship between Droceloncia and Argomuellera, the two remaining genera in the subtribe Pycnocominae. The genera allied as subtribe Blumeodendrinae, Blumeodendron, Podadenia, Ptychopyxis, and Botryophora, share pollen with short narrow colpi, a croton sculpture, and mostly irregular columellae. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. Kagawa Univ, Dept Biol, Takamatsu, Kagawa 7608522, Japan. Univ Calif Davis, Herbarium, Plant Biol Sect, Davis, CA 95616 USA. RP Nowicke, JW (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, NHB 166, Washington, DC 20560 USA. NR 18 TC 20 Z9 21 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0034-6667 J9 REV PALAEOBOT PALYNO JI Rev. Palaeobot. Palynology PD APR PY 1999 VL 105 IS 1-2 BP 1 EP 62 DI 10.1016/S0034-6667(98)00069-4 PG 62 WC Plant Sciences; Paleontology SC Plant Sciences; Paleontology GA 188UL UT WOS:000079867000001 ER PT J AU Filgueiras, TS Peterson, PM Herrera-Arrieta, Y AF Filgueiras, TS Peterson, PM Herrera-Arrieta, Y TI Rheochloa (Poaceae : Chloridoideae), a new genus from central Brazil SO SYSTEMATIC BOTANY LA English DT Article AB Rheochloa scabiflora Filg., P.M. Peterson & Y. Herrera, gen, et sp, nov., is described and illustrated. The new species occurs in humid grasslands of Municipio de Mineiros, Goias, Parque Nacional das Emas in central Brazil. It seems most closely allied with Dinebra but differs by its perennial habit, inflorescences composed of 3-5 subdigitate racemes, short pedicellate spikelets, glabrous lemmas that are ciliolate on the apex, and fusiform caryopses with persistent style bases. Rheochloa is tentatively placed in subtribe Eragrostidinae of tribe Eragrostideae. So far, R. scabriflora is known only from a single population located inside Parque Nacional das Emas (18 degrees 17'55 " S-52 degrees 43'79 " W). C1 IBGE, Reserva Ecol, BR-70312970 Brasilia, DF, Brazil. Smithsonian Inst, Natl Museum Amer Hist, Dept Bot, Washington, DC 20560 USA. Inst Politecn Nacl, COFAA, CIIDIR Unidad Durango, Durango 34000, Mexico. RP Filgueiras, TS (reprint author), IBGE, Reserva Ecol, Caixa Postal 08770, BR-70312970 Brasilia, DF, Brazil. NR 13 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PLANT TAXONOMISTS PI BRONX PA NEW YORK BOTANICAL GARDEN, BRONX, NY 10458-5126 USA SN 0363-6445 J9 SYST BOT JI Syst. Bot. PD APR-JUN PY 1999 VL 24 IS 2 BP 123 EP 127 DI 10.2307/2419543 PG 5 WC Plant Sciences; Evolutionary Biology SC Plant Sciences; Evolutionary Biology GA 225JG UT WOS:000081954100001 ER PT J AU Li, JH Dijkstra, P Hinkle, CR Wheeler, RM Drake, BG AF Li, JH Dijkstra, P Hinkle, CR Wheeler, RM Drake, BG TI Photosynthetic acclimation to elevated atmospheric CO2 concentration in the Florida scrub-oak species Quercus geminata and Quercus myrtifolia growing in their native environment SO TREE PHYSIOLOGY LA English DT Article; Proceedings Paper CT Workshop on Critical Assessment of the Response of Forest Ecosystems to Elevated Atmospheric Carbon Dioxide CY OCT 10-13, 1997 CL DURHAM, NORTH CAROLINA DE carbon dioxide; open-top chambers; Rubisco; specific leaf area; starch; sugar ID PINUS-TAEDA SEEDLINGS; GAS-EXCHANGE; CARBON-DIOXIDE; WATER-STRESS; LIQUIDAMBAR-STYRACIFLUA; GROWTH; ENRICHMENT; LEAVES AB Long-term effects of elevated CO2 concentration (ambient plus 350 mu mol mol(-1)) on leaf photosynthetic acclimation of two species of a scrub-oak community, Quercus myrtifolia Willd. and Quercus geminata Small, were studied. Plants of both species were grown in open-top chambers in their natural habitat at Kennedy Space Center, Florida, USA. Compared to ambient CO2, elevated CO2 stimulated photosynthetic rates by 73 and 51% for Q. geminata and Q. myrtifolia, respectively. Maximum rate of carboxylation (V-cmax) was significantly reduced by elevated CO2 in Q. myrtifolia (28%) but not in Q. geminata. Maximum rate of potential electron transport (J(max)) was not significantly reduced by elevated CO2 in either species. In response to elevated CO2, specific leaf area decreased in Q, myrtifolia (22%), but not in Q. geminata. Elevated CO:! caused a significant accumulation of sugars (54%) and starch (264%) in Q, myrtifolia leaves, but not in Q. geminata leaves. Total Rubisco activity in Q. myrtifolia leaves was reduced 40% by elevated CO2, whereas no significant reduction occurred in Q, geminata leaves. Although both species share a common habitat, they exhibited marked differences in photosynthetic acclimation to elevated CO2 concentration. C1 Natl Res Council, Kennedy Space Ctr, FL 32899 USA. Smithsonian CO2 Site, Kennedy Space Ctr, FL 32899 USA. Dynamac Corp, Kennedy Space Ctr, FL 32899 USA. NASA, Biomed Off, Kennedy Space Ctr, FL 32899 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Li, JH (reprint author), Natl Res Council, Mail Code JJ-G, Kennedy Space Ctr, FL 32899 USA. NR 25 TC 32 Z9 32 U1 0 U2 2 PU HERON PUBLISHING PI VICTORIA PA 202, 3994 SHELBOURNE ST, VICTORIA, BC V8N 3E2, CANADA SN 0829-318X J9 TREE PHYSIOL JI Tree Physiol. PD APR PY 1999 VL 19 IS 4-5 BP 229 EP 234 PG 6 WC Forestry SC Forestry GA 181NB UT WOS:000079446400004 ER PT J AU Ward, DC AF Ward, DC TI An artist's self-fashioning: the forging of Charles Willson Peale SO WORD & IMAGE LA English DT Article C1 Smithsonian Inst, Washington, DC 20560 USA. RP Ward, DC (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 83 TC 3 Z9 3 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0266-6286 J9 WORD IMAGE JI Word Image PD APR-JUN PY 1999 VL 15 IS 2 BP 107 EP 127 PG 21 WC Humanities, Multidisciplinary SC Arts & Humanities - Other Topics GA 202JZ UT WOS:000080650000001 ER PT J AU Post, JE AF Post, JE TI Manganese oxide minerals: Crystal structures and economic and environmental significance SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article; Proceedings Paper CT National-Academy-of-Sciences Colloquium on Geology, Mineralogy, and Human Welfare CY NOV 08-09, 1998 CL ARNOLD & MABEL BECKMAN CTR, IRVINE, CA SP Natl Acad Sci HO ARNOLD & MABEL BECKMAN CTR ID TODOROKITE BUSERITE PROBLEM; X-RAY-DIFFRACTION; RIETVELD REFINEMENT; STREAM SEDIMENTS; IRON-OXIDES; NODULES; OXIDATION; LITHIOPHORITE; WATER; DIOXIDE AB Manganese oxide minerals have been used for thousands of years-by the ancients for pigments and to clarify glass, and today as ores of Mn metal, catalysts, and battery material. More than 30 Mn oxide minerals occur in a wide variety of geological settings. They are major components of Mn nodules that pave huge areas of the ocean floor and bottoms of many fresh-water lakes. Mn oxide minerals are ubiquitous in soils and sediments and participate in a variety of chemical reactions that affect groundwater and bulk soil composition. Their typical occurrence as fine-grained mixtures makes it difficult to study their atomic structures and crystal chemistries. In recent years, however, investigations using transmission electron microscopy and powder x-ray and neutron diffraction methods have provided important new insights into the structures and properties of these materials. The crystal structures for todorokite and birnessite, two of the more common Mn oxide minerals in terrestrial deposits and ocean nodules, were determined by using powder x-ray diffraction data and the Rietveld refinement method. Because of the large tunnels in todorokite and related structures there is considerable interest in the use of these materials and synthetic analogues as catalysts and cation exchange agents. Birnessite-group minerals have layer structures and readily undergo oxidation reduction and cation-exchange reactions and play a major role in controlling groundwater chemistry. C1 Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. RP Post, JE (reprint author), Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. NR 105 TC 614 Z9 662 U1 35 U2 237 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAR 30 PY 1999 VL 96 IS 7 BP 3447 EP 3454 DI 10.1073/pnas.96.7.3447 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 182PT UT WOS:000079507900021 PM 10097056 ER PT J AU Forrey, RC Balakrishnan, N Dalgarno, A Haggerty, MR Heller, EJ AF Forrey, RC Balakrishnan, N Dalgarno, A Haggerty, MR Heller, EJ TI Quasiresonant energy transfer in ultracold atom-diatom collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID VIBRATION-ROTATION TRANSFER; H2 AB Quantum and classical quasiresonant vibration-rotation energy transfer is investigated for ultracold He-H(2) collisions. Classical trajectory computations show that extremely strong correlations between Delta j and Delta v persist at low energies, though the changes themselves are less than one quantum. Quantum computations show that quasiresonant transitions occur in the limit of zero collision energy but that threshold effects become important and that some quasiresonant channels close. The qualitative similarity between classical and quantum results suggests that they share a common mechanism. [S0031-9007(99)08787-6]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Harvard Univ, Dept Chem, Cambridge, MA 02138 USA. RP Forrey, RC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 18 TC 79 Z9 81 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 29 PY 1999 VL 82 IS 13 BP 2657 EP 2660 DI 10.1103/PhysRevLett.82.2657 PG 4 WC Physics, Multidisciplinary SC Physics GA 179UY UT WOS:000079348900009 ER PT J AU Stancil, PC Clarke, NJ Zygelman, B Cooper, DL AF Stancil, PC Clarke, NJ Zygelman, B Cooper, DL TI Ab initio study of charge transfer in low-energy Si3+ collisions with helium SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ATOMIC-HYDROGEN; ELECTRON-CAPTURE; SILICON; NEBULA; IONS AB Charge transfer cross sections for collisions of ground state Si3+(3s S-2) and excited state Si3+(3p P-2(o)) with atomic helium are presented for energies less than 250 eV u(-1). Using a fully quantum mechanical, molecular-orbital, close-coupling approach, the cross sections are calculated in a diabetic representation. Completely ab initio adiabatic potentials and nonadiabatic radial coupling matrix elements obtained with the spin-coupled valence-bond method are utilized. Rate coefficients for temperatures between 100 and 100 000 K and cross sections for collisions with isotopic He-3 are presented. Results for the reverse process, Si2+ + He+, are also given. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Birmingham, Sch Chem, Birmingham B15 2TT, W Midlands, England. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Liverpool, Dept Chem, Liverpool L69 7ZD, Merseyside, England. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. RP Stancil, PC (reprint author), Oak Ridge Natl Lab, Div Phys, POB 2008, Oak Ridge, TN 37831 USA. NR 20 TC 11 Z9 12 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD MAR 28 PY 1999 VL 32 IS 6 BP 1523 EP 1534 DI 10.1088/0953-4075/32/6/015 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 184GT UT WOS:000079603300015 ER PT J AU Balakrishnan, N Dalgarno, A AF Balakrishnan, N Dalgarno, A TI Rate coefficients for NO formation in energetic N+O-2 collisions SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SPACE-SHUTTLE EXPERIMENT; FAST NITROGEN-ATOMS; NITRIC-OXIDE; TERRESTRIAL THERMOSPHERE; ATMOSPHERIC REACTION; RATE CONSTANTS; KINETICS; SURFACE; (2)A'; DYNAMICS AB The reaction of energetic N atoms with O-2 is an important source of ro-vibrationally excited NO in the thermosphere. Cross-sections and rate coefficients are calculated using a quantum-classical approach and comparison is made with earlier calculations and with experimental data. Good agreement is obtained with previous theoretical calculations. Satisfactory agreement with experiment is obtained for the thermal rate coefficients at temperatures above 2000 K but the data at lower temperatures suggest that modifications are needed in the details of the potential energy surface of (2)A' symmetry. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Dalgarno, A (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. NR 22 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAR 26 PY 1999 VL 302 IS 5-6 BP 485 EP 488 DI 10.1016/S0009-2614(99)00166-9 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 180CM UT WOS:000079367600017 ER PT J AU Poe, S Swofford, DL AF Poe, S Swofford, DL TI Taxon sampling revisited SO NATURE LA English DT Letter ID PHYLOGENIES; PARSIMONY C1 Smithsonian Inst, Natl Museum Nat Hist, Div Amphibians & Reptiles, Washington, DC 20560 USA. Univ Texas, Dept Zool, Austin, TX 78712 USA. Univ Texas, Texas Mem Museum, Austin, TX 78712 USA. Smithsonian Inst, Lab Mol Systemat, Washington, DC 20560 USA. RP Poe, S (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Div Amphibians & Reptiles, MRC 162, Washington, DC 20560 USA. NR 10 TC 113 Z9 115 U1 1 U2 13 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAR 25 PY 1999 VL 398 IS 6725 BP 299 EP 300 DI 10.1038/18592 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 180DF UT WOS:000079369600036 PM 10192331 ER PT J AU Heyer, WR Munoz, AM AF Heyer, WR Munoz, AM TI Validation of Eleutherodactylus crepitans Bokermann, 1965, notes on the types and type locality of Telatrema heterodactylum Miranda-Ribeiro, 1937, and description of a new species of Eleutherodactylus from Mato Grosso, Brazil (Amphibia : Anura : Leptodactylidae) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID FROGS AB Examination of the types of Eleutherodactylus crepitans Bokermann, 1965, indicates that they represent a valid species, which should be removed from the synonymy of Eleutherodactylus fenestratus (Steindachner 1864). Eleutherodactylus crepitans is only known from the type material. Certain features of the types of Telatrema heterodactylum Miranda-Ribeiro, 1937, are described and the type locality clarified. Analysis of the advertisement call and morphology of a series of specimens from Chapada dos Guimaraes indicates that the specimens represent a species distinct from E. fenestratus (Stein dachner 1864), for which no name is available. We describe this new species as Eleutherodactylus dundeei. The frog fauna of Chapada dos Guimaraes contains four distinct historical units: cerrado, chaco, Amazonian hylaea, and endemic. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. New Mexico State Univ, Dept Biol, Las Cruces, NM 88003 USA. RP Heyer, WR (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. NR 19 TC 14 Z9 14 U1 0 U2 2 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD MAR 23 PY 1999 VL 112 IS 1 BP 1 EP 18 PG 18 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 182NQ UT WOS:000079505400001 ER PT J AU Heyer, WR AF Heyer, WR TI A new genus and species of frog from Bahia, Brazil (Amphibia : Anura : Leptodactylidae) with comments on the zoogeography of the Brazilian campos rupestres SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB A new genus and species of frog, Rupirana cardosoi, is described from the northern Espinhaco Range in the State of Bahia, Brazil. The new genus shares most character states with the genus Thoropa, but cladistic analysis of morphological data indicates that most of these shared features are primitive states. The cladistic analysis indicates that Rupirana and Thoropa do not have a close sister-group relationship with each other. Rupirana cardosoi is another addition to the many species endemic to the campos rupestres of the Espinhaco Range. The amphibians of the campos rupestres show a much stronger biogeographical affinity with the Atlantic Forest biota than other groups studied; these other groups show a much stronger affinity with the biota of the diagonal of open formations running from northeast Brazil (caatingas-cerrados) to Argentina and Paraguay (Gran Chaco). C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. RP Heyer, WR (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. NR 21 TC 17 Z9 23 U1 2 U2 2 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD MAR 23 PY 1999 VL 112 IS 1 BP 19 EP 39 PG 21 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 182NQ UT WOS:000079505400002 ER PT J AU Erdmann, MV Manning, RB AF Erdmann, MV Manning, RB TI A new species of Siamosquilla from Indonesia (Crustacea : Stomatopoda : Protosquillidae) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB Siamosquilla sexava, the second species of the genus, is described from Indonesia. It can be distinguished from the type species, S. hyllebergi Naiyanetr, from Thailand, by the shorter median rostral spine, the larger ocular scales, the much broader telson, and differences in ornamentation of the fused sixth abdominal somite and telson. C1 Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. Smithsonian Inst, Museum Natl Hist Nat, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Erdmann, MV (reprint author), Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD MAR 23 PY 1999 VL 112 IS 1 BP 94 EP 96 PG 3 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 182NQ UT WOS:000079505400008 ER PT J AU Bolstad, KS Kensley, B AF Bolstad, KS Kensley, B TI Two new species of Hansenium (Crustacea : Isopoda : Asellota) from Madang, Papua New Guinea SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB Two new species of Hansenium, H. tropex and H. thomasi, are described from Paddock Reef, Madang, Papua New Guinea. H. tropex is characterized by the possession of a broad oar-shaped lobe of the carpus of pereopod 1 in the male. H. thomasi is characterized by a narrow tapering mesially-directed lobe of the carpus of pereopod 1 of the male. The genus is redefined, with its chief character being the presence of a large carpal lobe on the first male pereopod. The eight stenetriid genera are compared on the basis of six characters. C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Bolstad, KS (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Dept Invertebrate Zool, Washington, DC 20560 USA. NR 24 TC 4 Z9 4 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD MAR 23 PY 1999 VL 112 IS 1 BP 164 EP 174 PG 11 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 182NQ UT WOS:000079505400015 ER PT J AU Robinson, H AF Robinson, H TI Two new subtribes, Stokesiinae and Pacourininae, of the Vernonieae (Asteraceae) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB New subtribes Stokesiinae and Pacourininae are established in the Vernonieae (Asteraceae) for the Southeastern United States genus Stokesia and the South American genus Pacourina. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. RP Robinson, H (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD MAR 23 PY 1999 VL 112 IS 1 BP 216 EP 219 PG 4 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 182NQ UT WOS:000079505400021 ER PT J AU Robinson, H AF Robinson, H TI Revisions in paleotropical Vernonieae (Asteraceae) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID BACCHAROIDES MOENCH; POLLEN MORPHOLOGY; COMPOSITAE AB The paleotropical subtribes Erlangeinae, Centrapalinae and Gymnantheminae are described as new. Fourteen paleotropical genera are described, raised from lower rank, resurrected, enlarged or reduced with 110 new combinations. Cabobanthus (2 spp.), Hilliardiella (8 spp.), Orbivestus (4 spp.), Vernoniastrum (8 spp.), Koyamasia (1 sp.), Brenandendron (3 spp.), Myanamaria (1 sp.) and Manyonia (1 sp.) are described as new. Oocephala (S. B. Jones) H. Rob. (2 spp.) and Lampropappus (O. Hoffm.) H. Rob. (3 spp.) are elevated to generic rank. Four genera are resurrected, the Asian Acilepis D. Don with 9 of 10 species newly combined, the African Bechium DC. (2 spp.), Centrapalus Cass. (9 spp.), Linzia Sch. Bip. ex Walp. with 5 of 7 species newly transferred, and Polydora Fenzl (8 spp.). One species is transferred to make a total of 27 in Distephanus, 4 species are transferred to total 7 in Cyanthillium, and 39 species are transferred to total 43 in Gymnanthemum. Lamprachaenium Benth. is synonymized with Phyllocephalum Blume with 1 species transferred. C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Bot, Washington, DC 20560 USA. RP Robinson, H (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Dept Bot, Washington, DC 20560 USA. NR 46 TC 31 Z9 37 U1 0 U2 3 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD MAR 23 PY 1999 VL 112 IS 1 BP 220 EP 247 PG 28 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 182NQ UT WOS:000079505400022 ER PT J AU Cornett, ST Sadeghpour, KR Cavagnero, MJ AF Cornett, ST Sadeghpour, KR Cavagnero, MJ TI Interferometric line shape modulation in alkali-halide photoabsorption SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM DEFECT THEORY; STATES; PREDISSOCIATION; PHOTODISSOCIATION; RESONANCES AB An ab initio calculation of the photoabsorption spectrum of ground state LiF below the ionic Li+ + F- threshold predicts a periodic modulation of the predissociation line shapes. Specifically, we predict a periodic reversal of Fano's line shape asymmetry parameter q. In this case, reversal of the q parameter occurs because of the interference of vibrational wave functions propagating alternatively along diabatic and adiabatic potentials. The interference modulates the predissociation spectrum giving rise to both extremely long-lived resonances and broad window resonances. These anomalous resonances occur periodically on an energy scale greater than the Rydberg energy spacing and are finite in number. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. RP Cornett, ST (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. NR 25 TC 16 Z9 16 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 22 PY 1999 VL 82 IS 12 BP 2488 EP 2491 DI 10.1103/PhysRevLett.82.2488 PG 4 WC Physics, Multidisciplinary SC Physics GA 178HH UT WOS:000079259800017 ER PT J AU Wikelski, M Hau, M Wingfield, JC AF Wikelski, M Hau, M Wingfield, JC TI Social instability increases plasma testosterone in a year-round territorial neotropical bird SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE testosterone; tropical bird; rainforest; territoriality; antbird; social challenge ID BROWED SPARROW WEAVER; RED-WINGED BLACKBIRDS; PLOCEPASSER-MAHALI; MELOSPIZA-MELODIA; REPRODUCTIVE SUCCESS; HORMONAL RESPONSES; STEROID-HORMONES; JUNCO-HYEMALIS; MATING SYSTEMS; SONG SPARROW AB In many vertebrates, elevated levels of plasma testosterone (T) are important for reproduction and territorial aggression. However, many tropical birds reproduce and defend territories while plasma T-levels are basal. We studied how aggression and T-levels are regulated in male neotropical spotted antbirds, which defend territories year-round in the Panamanian rainforest. Although spotted antbirds reproduce seasonally, T-levels of individual males often remained at baseline (0.2 ng ml(-1)) throughout the year, even in courting males. On the other hand, T-levels were elevated (maximally to 1.57 ng ml(-1)) during periods of social instability at any time of the year, even when males had entirely regressed gonads. Experimental territorial intrusions (broadcast of conspecific song) confirmed these observations by showing that T-levels increased after about two hours of playback time. Our data suggest that spotted antbirds avoided the potential costs associated with constantly high plasma T-levels (e.g. increased mortality rates). Contrary to temperate-zone birds, spotted antbirds had the potential to react to social challenges with an increase of plasma T year-round. These results are, to our knowledge, presently unique, but may apply to many vertebrate species that inhabit the tropics. C1 Univ Illinois, Dept Ecol Ethol & Evolut, Urbana, IL 61801 USA. Univ Washington, Dept Zool, Seattle, WA 98195 USA. Smithsonian Trop Res Inst, Balboa, Panama. RP Wikelski, M (reprint author), Univ Illinois, Dept Ecol Ethol & Evolut, 505 S Goodwin Ave,515 Morrill Hall, Urbana, IL 61801 USA. EM wikelski@uiuc.edu NR 53 TC 77 Z9 77 U1 0 U2 11 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD MAR 22 PY 1999 VL 266 IS 1419 BP 551 EP 556 DI 10.1098/rspb.1999.0671 PG 6 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA 181ZB UT WOS:000079472400003 ER PT J AU Allen, LE Burton, MG Ryder, SD Ashley, MCB Storey, JWV AF Allen, LE Burton, MG Ryder, SD Ashley, MCB Storey, JWV TI Fluorescent molecular hydrogen in the Eagle nebula SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE shock waves; ISM : clouds; ISM : individual : M16; ISM : molecules; infrared : ISM : lines and bands ID PHOTODISSOCIATION REGIONS; INTERSTELLAR H2; TELESCOPE AB We used the University of New South Wales infrared Fabre-Perot (UNSWIRF) to investigate the photodissociation region (PDR) associated with the 'elephant trunk' features in the M16 H II region (the Eagle nebula). Images were made in the H-2 1-0 S(1) and 2-1 S(1) lines at 2.122 and 2.248 mu m, respectively, and in the H I Br gamma line at 2.166 mu m. The trunk-like features have an average H-2 number density of similar to 10(4) cm(-3) and are irradiated by a far-UV held similar to 10(4) x the ambient interstellar value. The H-2 intensity profile across the trunks is consistent with a simple model in which cylindrical columns of gas are illuminated externally, primarily by a direct component (the stars of NGC 6611), with an additional contribution from an isotropic component (scattered light). We find that most of the H-2 emission from the source is consistent with purely fluorescent excitation, however a significant fraction of the H-2 emission (similar to 25 per cent) from the northernmost column shows evidence far 'collisional fluorescence', i.e, redistribution of H-2 level populations through collisions. This emission is confined to clumps up to similar to 0.01 pc in diameter, with densities greater than or equal to 10(5) cm(-3), and perhaps > 10(6) cm(-3), filling at most a few per cent of the volume of the trunks. The line intensities and ratios are consistent with steady-state and not time-dependent PDR models. C1 Univ New S Wales, Sch Phys, Sydney, NSW 2052, Australia. RP Allen, LE (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Burton, Michael/0000-0001-7289-1998; Ryder, Stuart/0000-0003-4501-8100 NR 16 TC 19 Z9 19 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAR 21 PY 1999 VL 304 IS 1 BP 98 EP 108 DI 10.1046/j.1365-8711.1999.02296.x PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182TA UT WOS:000079513200015 ER PT J AU Sakamoto, K Scoville, NZ Yun, MS Crosas, M Genzel, R Tacconi, LJ AF Sakamoto, K Scoville, NZ Yun, MS Crosas, M Genzel, R Tacconi, LJ TI Counterrotating nuclear disks in ARP 220 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : individual (Arp 220); galaxies : interactions; galaxies : ISM ID ULTRALUMINOUS INFRARED GALAXIES; MOLECULAR GAS; ARP-220; IC-4553; SPECTROSCOPY; EMISSION AB The ultraluminous infrared galaxy Arp 220 has been observed at 0 ".5 resolution in CO (2-1) and 1 mm continuum using the newly expanded Owens Valley Millimeter Array. The CO and continuum peaks at the double nuclei and the surrounding molecular gas disk are clearly resolved. We find steep velocity gradients across each nucleus (Delta V similar to 500 km s(-1) within I = 0 ".3) whose directions are not aligned with each other and with that of the outer gas disk. We conclude that the double nuclei have their own gas disks (I similar to 100 pc), are counterrotating with respect to each other, and are embedded in the outer gas disk (r similar to 1 kpc) rotating around the dynamical center of the system. The masses of each nucleus are M-dyn greater than or similar to 2 x 10(9) M., based on the CO kinematics. Although there is no evidence of an old stellar population in the optical or near-infrared spectroscopy of the nuclei (probably owing to the much brighter young population), it seems likely that these nuclei were "seeded" from the premerger nuclei in view of their counterrotating gas kinematics. The gas disks probably constitute a significant fraction (similar to 50%) of the mass in each nucleus. The CO and continuum brightness temperatures imply that the nuclear gas disks have high area filling factors (similar to 0.5-1) and extremely high visual extinctions (A(V) similar or equal to 1000 mag). The molecular gas must be hot (greater than or equal to 40 K) and dense (greater than or equal to 10(4-5) cm(-3)), given the large mass and small scale height of the nuclear disks. The continuum data suggest that the large luminosity (be it starburst or active galactic nucleus) must originate within less than or similar to 100 pc of the two nuclear gas disks, which were presumably formed through concentration of gas from the progenitor outer galaxy disks. C1 CALTECH, Pasadena, CA 91125 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. RP Sakamoto, K (reprint author), CALTECH, Pasadena, CA 91125 USA. NR 29 TC 159 Z9 159 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 1999 VL 514 IS 1 BP 68 EP 76 DI 10.1086/306951 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BE UT WOS:000080057000007 ER PT J AU Kataoka, J Mattox, JR Quinn, J Kubo, H Makino, F Takahashi, T Inoue, S Hartman, RC Madejski, GM Sreekumar, P Wagner, SJ AF Kataoka, J Mattox, JR Quinn, J Kubo, H Makino, F Takahashi, T Inoue, S Hartman, RC Madejski, GM Sreekumar, P Wagner, SJ TI High-energy emission from the TeV blazar Markarian 501 during multiwavelength observations in 1996 SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : individual (Markarian 501); gamma rays : observations; radiation mechanisms : nonthermal; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; SELF-COMPTON MODEL; GAMMA-RAY EMISSION; LACERTAE OBJECT MARKARIAN-421; X-RAY; RELATIVISTIC JETS; SPHERICAL GEOMETRIES; GALAXY MARKARIAN-421; VARIABILITY; FLARE AB We present the results of a multiwavelength campaign for Mrk 501 performed in 1996 March with ASCA, EGRET, Whipple, and optical telescopes. The X-ray flux observed with ASCA was 5 times higher than the quiescent level and gradually decreased by a factor of 2 during the observation in 1996 March. In the X-ray band, a spectral break was observed around 2 keV. We report here for the first time the detection of high-energy gamma-ray flux from Mrk 501 with EGRET with 3.5 sigma significance (E > 100 MeV). Higher flux was also observed in 1996 April-May, with 4.0 sigma significance for E > 100 MeV and 5.2 sigma significance for E > 500 MeV. The gamma-ray spectrum was measured to be flatter than most of the gamma-ray blazars. We find that the multiband spectrum in 1996 is consistent with that calculated from a one-zone synchrotron self-Compton (SSC) model in which X-rays are produced via synchrotron emission and gamma-rays are produced via inverse Compton scattering of synchrotron photons in a homogeneous region. The flux of TeV gamma-rays is consistent with the predictions of the model if the decrease of the Compton scattering cross section in the Klein-Nishina regime is considered. In the context of this model, we investigate the values of the magnetic field strength and the beaming factor allowed by the observational results. We compare the 1996 March multiwavelength spectrum with that in the flare state in 1997 April. Between these two epochs, the TeV flux increase is well correlated with that observed in keV range. The keV and TeV amplitudes during the 1997 April hare are accurately reproduced by a one-zone SSC model, assuming that the population of synchrotron photons in 1996 are scattered by newly injected relativistic electrons having maximum energies of gamma(max) similar to 6 x 10(6). However, the TeV spectrum observed during the 1996 March campaign is flatter than predicted by our models. We find that this cannot be explained by either higher order Comptonization or the contribution of the "seed" IR photons from the host galaxy for the first-order external radiation. Comptonization, but we cannot exclude possible effects of the IR photons that may arise in the parsec-size tori postulated to exist in active galactic nuclei. C1 Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. Boston Univ, Dept Astron, Boston, MA 02215 USA. Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA. Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo 1920397, Japan. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Landessternwarte Heidelberg, D-69117 Heidelberg, Germany. RP Kataoka, J (reprint author), Inst Space & Astronaut Sci, 3-1-1 Yoshinodai, Kanagawa 2298510, Japan. NR 61 TC 120 Z9 120 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 1999 VL 514 IS 1 BP 138 EP 147 DI 10.1086/306918 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BE UT WOS:000080057000013 ER PT J AU Gomez, JF Sargent, AI Torrelles, JM Ho, PTP Rodriguez, LF Canto, J Garay, G AF Gomez, JF Sargent, AI Torrelles, JM Ho, PTP Rodriguez, LF Canto, J Garay, G TI Disk and outflow in Cepheus A-HW2: Interferometric SiO and HCO+ observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (Cepheus A); ISM : jets and outflows; ISM : molecules; stars : pre-main-sequence ID MOLECULAR LINE EMISSION; STAR-FORMING REGION; PROTOPLANETARY DISKS; MASS OUTFLOW; OBJECTS; BIPOLAR; MODELS; MASERS; CLOUDS; JETS AB This paper reports observations of the HCO+ (1 --> 0) and SiO (2 --> 1) lines and of continuum emission at lambda= 3.4 mm toward the Cepheus A East star-forming region. The HCO+ line shows emission up to velocities of similar to 50 km s(-1) relative to the ambient cloud velocity. The spatial distribution of the high-velocity gas is bipolar, centered on HW2, and extends for similar to 1' along P.A. = 55 degrees-60 degrees. The orientation of this molecular outflow is very similar to that of the radio jet and CO emission associated with HW2. This confirms that current mass loss from HW2 takes place in the northeast-southwest direction. The momentum rate of the HCO+ outflow is 1.3 x 10(-2) M-. km s(-1) yr(-1), 20 times larger than that of the ionized jet from HW2, suggesting that the jet could be largely neutral. Peaks of HCO+ emission coincide with some of the radio-continuum sources in the region, consistent with outflow-ambient gas interaction. Multiple episodes of outflow activity from either one precessing source or a number of powering sources would explain the detection of moderate-velocity HCO+ emission toward the HW7 chain of sources. The continuum emission at 3.4 mm is strongly peaked toward HW2, confirming that this is the most likely powering source for the outflow. The SiO emission is barely elongated along P.A. = -33 degrees, i.e., almost perpendicular to the HCO+ outflow. A velocity trend consistent with a gradient of similar to 31 km s(-1) over 2 " is detected along the major axis of the SiO structure; these motions could be bound by 200 M-.. Published H2O and CS observations support our suggestion that this represents the outer, similar to 750 AU radius, part of a circumstellar disk, although further observations are needed to confirm this interpretation. C1 INTA, Lab Astrofis Espacial & Fis Fundamental, E-28080 Madrid, Spain. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. Univ Illes Balears, CSIC, Inst Mediterraneo Estudios Avanzados, E-07071 Palma de Mallorca, Spain. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Autonomous Univ Mexico, Astron Inst, Mexico City 04510, DF, Mexico. Univ Chile, Dept Astron, Santiago, Chile. RP Gomez, JF (reprint author), INTA, Lab Astrofis Espacial & Fis Fundamental, Apdo Correos 50727, E-28080 Madrid, Spain. RI Garay, Guido/H-8840-2013; Gomez, Jose Francisco/D-8392-2016; OI Garay, Guido/0000-0003-1649-7958; Gomez, Jose Francisco/0000-0002-7065-542X; Torrelles, Jose Maria/0000-0002-6896-6085 NR 35 TC 46 Z9 46 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 1999 VL 514 IS 1 BP 287 EP 295 DI 10.1086/306916 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BE UT WOS:000080057000024 ER PT J AU Balakrishnan, N Forrey, RC Dalgarno, A AF Balakrishnan, N Forrey, RC Dalgarno, A TI Quantum-mechanical study of ro-vibrational transitions in H-2 induced by He atoms SO ASTROPHYSICAL JOURNAL LA English DT Article DE molecular data; molecular processes ID ROVIBRATIONAL EXCITATION; SWS SPECTROSCOPY; ENERGY SURFACE; RELAXATION; COLLISIONS; MINIMUM; REGION AB We describe quantum-mechanical scattering calculations of re-vibrational transitions in H-2 induced by collisions with He. We use a close-coupled description of the dynamics which includes full re-vibrational coupling and a reliable potential energy surface. Rate coefficients for rotational and vibrational transitions in ortho- and para-H-2 are presented in the temperature range 10 less than or equal to T less than or equal to 5000 K. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Balakrishnan, N (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. NR 22 TC 24 Z9 24 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 1999 VL 514 IS 1 BP 520 EP 523 DI 10.1086/306922 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BE UT WOS:000080057000043 ER PT J AU Kaaret, P Piraino, S Ford, EC Santangelo, A AF Kaaret, P Piraino, S Ford, EC Santangelo, A TI Discovery of microsecond soft lags in the X-ray emission of the atoll source 4U 1636-536 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; stars : individual (4U 1608-52, 4U 1636-536); stars : neutron; X-rays : stars ID PROPORTIONAL COUNTER; TIMING EXPLORER; BINARIES AB Exploiting the presence of kilohertz quasi-periodic oscillations (QPOs) in the timing power spectrum, we find that the soft X-ray emission of the neutron star X-ray binary and atoll source 4U 1636-536, modulated at the QPO frequency, lags behind that of the hard X-ray emission. Emission in the 3.8-6.4 keV band is delayed by 25.0 +/- 3.3 mu s relative to the 9.3-69 keV band. The delay increases in magnitude with increasing energy. The soft lag could be produced by Comptonization of hard photons injected into a cooler electron cloud or by intrinsic spectral softening of the emission during each oscillation cycle. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CNR, Ist Fis Cosm & Applicaz Informat, I-90146 Palermo, Italy. Univ Palermo, Ist Fis, I-90123 Palermo, Italy. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. RP Kaaret, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 10 TC 25 Z9 26 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 1999 VL 514 IS 1 BP L31 EP L33 DI 10.1086/311941 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192BG UT WOS:000080057200009 ER PT J AU Lanza, RP Arrow, KJ Axelrod, J Baltimore, D Benacerraf, B Bloch, KE Bloembergen, N Brown, HC Brown, MS Cibelli, JB Cohen, S Cooper, LN Corey, EJ Dulbecco, R Fischer, EH Fitch, VL Friedman, JI Friedman, M Furchgott, RF Gell-Mann, M Glaser, DA Glashow, SL Gilbert, W Goldstein, JL Gould, SJ Guillemin, R Hauptman, HK Hauptman, HA Herschbach, D Hoffman, R Hood, L Hubel, DH Karle, J Klein, LR Kohn, W Kornberg, A Krebs, EG Lederman, LM Lederberg, J Lee, DM Lucas, RE Marcus, RA Merrifield, RB Miller, MH Modigliani, F Molina, MJ Mullis, K Murad, F Murray, JE Nathans, D Nirenberg, MW North, DC Olah, GA Palade, GE Perl, MJ Ramsey, NF Richter, B Roberts, RJ Robl, JM Samuelson, PA Schwartz, M Sharp, PA Smalley, RE Smith, HO Solow, RM Taube, H Tonegawa, S Watson, JD Weinberg, S Weller, TH West, MD Wieschaus, EF Wiesel, TN Wilson, RW AF Lanza, RP Arrow, KJ Axelrod, J Baltimore, D Benacerraf, B Bloch, KE Bloembergen, N Brown, HC Brown, MS Cibelli, JB Cohen, S Cooper, LN Corey, EJ Dulbecco, R Fischer, EH Fitch, VL Friedman, JI Friedman, M Furchgott, RF Gell-Mann, M Glaser, DA Glashow, SL Gilbert, W Goldstein, JL Gould, SJ Guillemin, R Hauptman, HK Hauptman, HA Herschbach, D Hoffman, R Hood, L Hubel, DH Karle, J Klein, LR Kohn, W Kornberg, A Krebs, EG Lederman, LM Lederberg, J Lee, DM Lucas, RE Marcus, RA Merrifield, RB Miller, MH Modigliani, F Molina, MJ Mullis, K Murad, F Murray, JE Nathans, D Nirenberg, MW North, DC Olah, GA Palade, GE Perl, MJ Ramsey, NF Richter, B Roberts, RJ Robl, JM Samuelson, PA Schwartz, M Sharp, PA Smalley, RE Smith, HO Solow, RM Taube, H Tonegawa, S Watson, JD Weinberg, S Weller, TH West, MD Wieschaus, EF Wiesel, TN Wilson, RW TI Science over politics SO SCIENCE LA English DT Letter C1 Stanford Univ, Sch Med, Stanford, CA 94309 USA. NIMH, Bethesda, MD 20892 USA. CALTECH, Pasadena, CA 91125 USA. Dana Farber Canc Inst, Boston, MA 02215 USA. Harvard Univ, Sch Med, Cambridge, MA 02138 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Texas, SW Med Ctr, Dallas, TX 75235 USA. Adv Cell Technol, Worcester, MA 01605 USA. Vanderbilt Univ, Sch Med, Nashville, TN 37232 USA. Brown Univ, Providence, RI 02912 USA. Salk Inst Biol Studies, La Jolla, CA 92037 USA. Univ Washington, Seattle, WA 98195 USA. Princeton Univ, Princeton, NJ 08544 USA. MIT, Cambridge, MA 02139 USA. Stanford Univ, Hoover Inst, Stanford, CA 94305 USA. SUNY, Brooklyn, NY 11203 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Hauptman Woodward Med Res, Buffalo, NY 14203 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Penn, Philadelphia, PA 19104 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. IIT, Chicago, IL 60616 USA. Rockefeller Univ, New York, NY 10021 USA. Univ Chicago, Chicago, IL 60637 USA. Univ Texas, Sch Med, Houston, TX 75225 USA. Johns Hopkins Univ, Baltimore, MD 21205 USA. NHLBI, Bethesda, MD 20892 USA. Washington Univ, St Louis, MO 63130 USA. Univ So Calif, Los Angeles, CA 90007 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. New England Biolabs Inc, Beverly, MA 01915 USA. Univ Massachusetts, Amherst, MA 01003 USA. Rice Univ, Houston, TX 77005 USA. Johns Hopkins Sch Med, Baltimore, MD 21205 USA. Cold Spring Harbor Lab, Cold Spring Harbor, NY 11724 USA. Univ Texas, Austin, TX 78712 USA. Harvard Univ, Sch Publ Hlth, Boston, MA 02115 USA. Princeton Univ, Princeton, NJ 08544 USA. Rockefeller Univ, New York, NY 10021 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. EM BobLanza@aol.com NR 0 TC 6 Z9 6 U1 11 U2 28 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD MAR 19 PY 1999 VL 283 IS 5409 BP 1849 EP 1850 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 177UC UT WOS:000079228600016 PM 10206888 ER PT J AU Murray, N Holman, M AF Murray, N Holman, M TI The origin of chaos in the outer solar system SO SCIENCE LA English DT Article ID ASTEROID BELT; COMPANION; NEPTUNE; MOTION; PLUTO; ORBIT; STAR AB Classical analytic theories of the solar system indicate that it is stable, but numerical integrations suggest that it is chaotic. This disagreement is resolved by a new analytic theory. The theory shows that the chaos among the jovian planets results from the overlap of the components of a mean motion resonance among Jupiter, Saturn, and Uranus, and provides rough estimates of the Lyapunov time (10(7) years) and the dynamical lifetime of Uranus (10(18) years). The jovian planets must have entered the resonance after all the gas and most of the planetesimals in the protoplanetary disk were removed. C1 Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Murray, N (reprint author), Univ Toronto, Canadian Inst Theoret Astrophys, 60 St George St, Toronto, ON M5S 3H8, Canada. NR 32 TC 80 Z9 81 U1 0 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD MAR 19 PY 1999 VL 283 IS 5409 BP 1877 EP 1881 DI 10.1126/science.283.5409.1877 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 177UC UT WOS:000079228600036 ER PT J AU Blake, GA Qi, C Hogerheijde, MR Gurwell, MA Muhleman, DO AF Blake, GA Qi, C Hogerheijde, MR Gurwell, MA Muhleman, DO TI Sublimation from icy jets as a probe of the interstellar volatile content of comets SO NATURE LA English DT Article ID HALE-BOPP C/1995-O1; WATER; ABUNDANCES; EVOLUTION; CHEMISTRY; HYAKUTAKE; RATIO AB Comets are some of the most primitive bodies left over from the Solar System's early history. They may preserve both interstellar material and material from the proto-solar nebula, and so studies of their volatile components can provide dues about the evolution of gases and ices, as a collapsing molecular cloud transforms into a mature planetary system(1,2). Previous observations of emission from rotational transitions in molecules have averaged over large areas of the inner coma, and therefore include both molecules that sublimed from the nucleus and those that result from subsequent chemical processes in the coma. Here we present high-resolution observations of emission from the molecules HNC, DCN and HDO associated with comet Hale-Bopp, Our data reveal are-like structures-icy jets-offset from (but close to) the nucleus. The measured abundance ratios on 1-3" scales are substantially different from those on larger scales(3-5), and cannot be accounted for by models of chemical processes in the coma(2,6,7); they ape, however, similar to the values observed in the cores of dense interstellar clouds and young stellar objects. We therefore propose that sublimation from millimetre-sized icy grains ejected from the nucleus provides access to relatively unaltered volatiles. The D/H ratios inferred from our data suggest that, by mass, Hale-Bopp (and by inference the outer regions of the early solar nebula) consists of greater than or equal to 15-40% of largely unprocessed interstellar material. C1 CALTECH 150 21, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Blake, GA (reprint author), CALTECH 150 21, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. NR 28 TC 50 Z9 50 U1 0 U2 4 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAR 18 PY 1999 VL 398 IS 6724 BP 213 EP 216 DI 10.1038/18372 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 177UA UT WOS:000079228400044 PM 10094044 ER PT J AU Lucas, SG Emry, RJ AF Lucas, SG Emry, RJ TI Taxonomy and biochronological significance of Paraentelodon, a giant entelodont (Mammalia, Artiodactyla) from the late Oligocene of Eurasia SO JOURNAL OF VERTEBRATE PALEONTOLOGY LA English DT Article AB Paraentelodon Gabuniya, 1964 (=Neoentelodon Aubekerova, 1969) is a giant entelodont known from the Georgian Republic, Kazakstan, and Gansu, People's Republic of China. The genus is distinguished by the following autapomorphies: I1/i1 much smaller than I2/i2, which are slightly smaller than I3/i3; single, large, flange-like dentary tubercle under p2: p2 very large and larger than p4; and upper molars (especially M2) with well-developed paraconules and metaconules. The few known specimens of Paraentelodon represent a single species, P. intermedium Gabuniya, 1964 (=N. dzhungaricus Aubekerova, 1969; =P. macrognathus Qiu, Xie and Yan, 1990). All Paraentelodon localities appear to be of late Oligocene age, not early Miocene as some previous workers have claimed. C1 New Mexico Museum Nat Hist & Sci, Albuquerque, NM 87104 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Paleobiol, Washington, DC 20560 USA. RP Lucas, SG (reprint author), New Mexico Museum Nat Hist & Sci, 1801 Mt Rd NW, Albuquerque, NM 87104 USA. NR 44 TC 5 Z9 5 U1 1 U2 1 PU SOC VERTEBRATE PALEONTOLOGY PI NORTHBROOK PA 60 REVERE DR, STE 500, NORTHBROOK, IL 60062 USA SN 0272-4634 J9 J VERTEBR PALEONTOL JI J. Vertebr. Paleontol. PD MAR 15 PY 1999 VL 19 IS 1 BP 160 EP 168 PG 9 WC Paleontology SC Paleontology GA 265TA UT WOS:000084258600014 ER PT J AU Field, GB Blackman, EG Chou, HS AF Field, GB Blackman, EG Chou, HS TI Nonlinear alpha-effect in dynamo theory SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; turbulence ID TURBULENT ELECTROMOTIVE-FORCE; WEAK MAGNETIC-FIELD; MAGNETOHYDRODYNAMIC TURBULENCE; TRANSPORT; HELICITY AB The standard two-scale theory of the dynamo coefficient alpha in incompressible isotropic helical MHD turbulence is extended to include nonlinear effects of (B) over bar, the large-scale magnetic field. We express alpha in terms of statistical quantities that can be calculated from numerical simulations of the case (B) over bar = 0. For large magnetic Reynolds numbers, our formula agrees approximately with that of Kraichnan but disagrees with that of Cattaneo & Hughes. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Theoret Astrophys Grp, Pasadena, CA 91125 USA. Harvard Univ, Dept Astron, Cambridge, MA 02138 USA. RP Field, GB (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,Mail Stop 51, Cambridge, MA 02138 USA. NR 37 TC 72 Z9 72 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 1999 VL 513 IS 2 BP 638 EP 651 DI 10.1086/306877 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YG UT WOS:000079816000011 ER PT J AU Donnelly, RH Markevitch, M Forman, W Jones, C Churazov, E Gilfanov, M AF Donnelly, RH Markevitch, M Forman, W Jones, C Churazov, E Gilfanov, M TI A hot spot in coma SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (coma); intergalactic medium; X-rays : galaxies ID X-RAY SOURCES; GALAXY CLUSTERS; SUBSTRUCTURE; GAS; SIMULATIONS; ABELL-754; COLLISION; EVOLUTION; DYNAMICS AB We study the temperature structure of the central part (r less than or equal to 18' similar or equal to 0.7 h(50)(-1) Mpc) of the Coma Cluster of galaxies using ASCA data Two different analysis methods produce results in good agreement with each other and reveal the presence of interesting structures in the gas temperature distribution. Globally, the average temperature in the center of the cluster is 9.0 +/- 0.6 keV, which is in good agreement with previous results. Superimposed on this we find a cool area with temperatures of 4-6 keV associated with a filament of X-ray emission extending southeast from the cluster center and detected by Vikhlinin and coworkers. We also find a hot spot with a temperature of around 13 keV displaced north from the central peak of emission. The distribution of the gas temperatures and relative specific entropies suggests that the cool features are most likely gas stripped from a galaxy group centered on NGC 4874 and falling toward the core from outside, while the hot spot located "ahead" of this infalling gas is due to shock heating. Thus our results suggest that we are observing Coma during a minor merger with a small group of galaxies associated with NGC 4874 shortly before the initial core passage. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Moscow Space Res Inst, IKI, Moscow 117810, Russia. Max Planck Inst Astrophys, D-85740 Garching, Germany. RP Donnelly, RH (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Churazov, Eugene/A-7783-2013 NR 35 TC 39 Z9 39 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 1999 VL 513 IS 2 BP 690 EP 694 DI 10.1086/306901 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YG UT WOS:000079816000016 ER PT J AU Coil, AL Ho, PTP AF Coil, AL Ho, PTP TI Infalling gas toward the Galactic center SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxy : center; ISM : clouds; ISM : molecules; radio lines : ISM ID APERTURE SYNTHESIS OBSERVATIONS; MOLECULAR ENVIRONMENT; INTERSTELLAR AMMONIA; NEUTRAL DISK; IONIZED-GAS; A COMPLEX; SGR-A; GALAXY; SUBMILLIMETER; SAGITTARIUS AB VLA maps of ammonia emission were made for the Galactic center region. The NH3(1, 1) and NH3(2, 2) transitions were observed in three 2' x 2' fields covering Sgr A* and the region 3' immediately south of it. In the central 3 pc surrounding Sgr A* we find emission that appears to be associated with the circumnuclear disk (CND), both morphologically and kinematically;This central emission is-connected to a long, narrow 2 pc x 10 pc streamer of clumpy molecular gas located toward the south, which appears to be carrying gas from the nearby 20 km s(-1) giant molecular cloud (GMC) to the circumnuclear region. We find a velocity gradient along the streamer, with, progressively higher velocities as the gas approaches Sgr A*. The streamer stops at the location of the CND, where the line width of the NH3 emission increases dramatically. This may be the kinematic signature of accretion onto the CND. The ratio of the NH3(2, 2)/NH3(1, 1) emission indicates that the gas is heated at the northern tip of the streamer, located inside the eastern edge of the CND. The morphology, kinematics, and temperature gradients of the gas all indicate that the southern streamer is located at the Galactic center and is interacting with the circumnuclear region. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Coil, AL (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St MS-78, Cambridge, MA 02138 USA. NR 36 TC 45 Z9 45 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 1999 VL 513 IS 2 BP 752 EP 766 DI 10.1086/306875 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YG UT WOS:000079816000021 ER PT J AU Wilner, DJ Reid, MJ Menten, KM AF Wilner, DJ Reid, MJ Menten, KM TI The synchrotron jet from the H2O maser source in W3(OH) SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (W3); ISM : jets and outflows; masers; radiation mechanisms : nonthermal; radio continuum : ISM; stars : formation ID STAR-FORMING REGION; RADIO-SOURCES; CHEMICAL VARIATIONS; ORION NEBULA; GHZ; EMISSION AB We report results of sensitive Very Large Array observations of the 8.4 GHz continuum emission associated with the TW object, a luminous young star located at the center of expansion of the H2O masers in the W3(OH) region. The source has a radio spectral index of -0.6 and exhibits a sinuous double-sided morphology; these are characteristics of a synchrotron jet. No significant changes are seen in the jet morphology in observations separated by 510 days. The inhomogeneous synchrotron model proposed by Reid et al., which is based on the spectrum and size variation with observing frequency, correctly predicts the flux density profile of the radio emission. Secondary radio continuum features located at the extrema of the H2O maser distribution may mark the location of strong shocks and deeply embedded Herbig-Haro objects or additional young stellar objects in the W3(OH) cluster. Several more compact sources are identified in the region, some of which are highly variable. These may be low-mass pre-main-sequence stars with magnetic activity. C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Max Planck Inst Radioastron, D-53121 Bonn, Germany. RP Wilner, DJ (reprint author), Smithsonian Astrophys Observ, 60 Garden St, Cambridge, MA 02138 USA. NR 17 TC 55 Z9 55 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 1999 VL 513 IS 2 BP 775 EP 779 DI 10.1086/306907 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YG UT WOS:000079816000023 ER PT J AU Menou, K Narayan, R Lasota, JP AF Menou, K Narayan, R Lasota, JP TI A population of faint nontransient low-mass black hole binaries SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; black hole physics; instabilities; X-rays : stars ID ADVECTION-DOMINATED ACCRETION; X-RAY TRANSIENTS; DISK-INSTABILITY MODEL; GRO J0422+32; V404 CYGNI; THERMAL-INSTABILITY; EVOLUTIONARY STATUS; NOVA OPHIUCHI-1977; ORBITAL PARAMETERS; MAGNETIC BRAKING AB We study the thermal and viscous stability of accretion flows in low-mass black hole binaries (LMBHBs). We consider a model in which an inner advection-dominated accretion flow (ADAF) is surrounded by a geometrically thin accretion disk, the transition between the two zones occurring at a radius R-tr. In all known LMBHBs, R-tr appears to be such that the outer disks could suffer from global thermal-viscous instability. This instability is likely to cause the transient behavior of these systems. However, in most cases, if R-tr were slightly larger than the estimated values, the systems would be globally stable. This suggests that a population of faint persistent LMBHBs with globally stable outer disks could be present in the Galaxy. Such LMBHBs would be hard to detect because they would lack large-amplitude outbursts and because their ADAF zones would have very low radiative efficiencies, making the systems very dim. We present model spectra of such systems covering the optical and X-ray bands. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Observ Paris, Sect Meudon, CNRS, UPR 176,Dept Astrophys Relativiste & Cosmol, F-92195 Meudon, France. RP Menou, K (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 93 TC 35 Z9 35 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 1999 VL 513 IS 2 BP 811 EP 826 DI 10.1086/306878 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YG UT WOS:000079816000026 ER PT J AU Woo, R Habbal, SR Howard, RA Korendyke, CM AF Woo, R Habbal, SR Howard, RA Korendyke, CM TI Extension of the polar coronal hole boundary into interplanetary space SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona ID SOLAR-WIND; WHITE-LIGHT; PHYSICAL-PROPERTIES; SCALE STRUCTURES; ULYSSES; STREAMERS; EXPANSION; MINIMUM; SPEED; SLOW AB White-light measurements made by the SOHO LASCO C2 and C3 coronagraphs and the Mk III Mauna Loa K-coronameter, ranging from 1.15 to 30 R. have been combined with Kitt Peak daily He I 1083 nm coronal hole maps, and full Sun Yohkoh soft X-ray images, to show that the boundaries of polar coronal holes, as determined by measurements of path-integrated density, extend approximately radially into interplanetary space. These results are in contrast to the long-standing view that the boundaries of polar coronal holes diverge significantly beyond radial, evolving around the edges of streamers. The combined observations also show that the corona is dominated by raylike structures as small as a few degrees in angular size with respect to Sun center, originating from both coronal holes and the quiet Sun. This analysis provides further support for results originally derived from radio occultation measurements, namely, that the coronal density projects itself almost radially from the Sun into the outer corona, implying that open field lines abound in the quiet Sun from which the fast wind can also originate. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Woo, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 238-725, Pasadena, CA 91109 USA. NR 26 TC 14 Z9 14 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 1999 VL 513 IS 2 BP 961 EP 968 DI 10.1086/306899 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YG UT WOS:000079816000041 ER PT J AU Millan-Gabet, R Schloerb, FP Traub, WA Malbet, F Berger, JP Bregman, JD AF Millan-Gabet, R Schloerb, FP Traub, WA Malbet, F Berger, JP Bregman, JD TI Sub-astronomical unit structure of the near-infrared emission from AB Aurigae SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; stars : emission-line, Be; stars : individual (AB Aurigae); stars : pre-main-sequence; techniques : interferometric ID HERBIG AE/BE STARS; INTERMEDIATE-MASS STARS; CIRCUMSTELLAR MATTER; DISKS; EXCESS; LINES; DUST AB We present near-infrared, long-baseline, interferometric observations of AB Aurigae, a well-known Herbig Ae/ Be star, obtained with the Infrared Optical Telescope Array. The near-infrared emission from this source has been spatially resolved for the first time, and the observations indicate a characteristic diameter of 5 mas for the emission, corresponding to 0.7 AU at the distance of AB Aur. The data appear to be most consistent with models in which the circumstellar material around AB Aurigae lies in a Battened structure with a central large hole or optically thin region of radius about 0.3 AU. C1 Univ Massachusetts, Dept Phys & Astron, Amherst, MA 01003 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Observ Grenoble, Astrophys Lab, F-38041 Grenoble, France. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Millan-Gabet, R (reprint author), Univ Massachusetts, Dept Phys & Astron, Amherst, MA 01003 USA. NR 19 TC 53 Z9 53 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 1999 VL 513 IS 2 BP L131 EP L134 DI 10.1086/311926 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YJ UT WOS:000079816200011 ER PT J AU Wilson, AS Raymond, JC AF Wilson, AS Raymond, JC TI Do jet-driven shocks ionize the narrow-line regions of Seyfert galaxies? SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : ISM; galaxies : jets; galaxies : nuclei; galaxies : Seyfert; shock waves ID X-RAY; RADIO; MODEL; EMISSION; BOWSHOCKS; NGC-1068; SPECTRUM; N132D; WAVES AB We consider a model in which the narrow-line regions (NLRs) of Seyfert galaxies are photoionized "in situ" by fast (300-1000 km s(-1)) radiative shock waves driven into the interstellar medium of the galaxy by radio jets from the active nucleus. Such shocks are powerful sources of soft X-rays. We compute the expected ratio of the count rates in the ROSAT PSPC and Einstein IPC detectors to the [O III] lambda 5007 flux as a function of shock velocity, and we compare these ratios with observations of type 2 Seyfert galaxies. If most of the observed soft X-ray emission from these galaxies originates in the NLR and the absorbing hydrogen column is similar to that inferred from the reddening of the NLR, a photoionizing shock model with a shock velocity of similar or equal to 400-500 km s(-1) is compatible with the observed ratios. High angular resolution observations with the Advanced X-Ray Astrophysics Facility are needed to isolate the X-ray emission of the NLR and measure its absorbing column, thus providing a more conclusive test. We also calculate the expected coronal iron line emission from the shocks. For most Seyfert 2 galaxies, the [Fe x] lambda 6374/H beta ratio is a factor of 2-14 lower than the predictions of 300-500 km s(-1) shock models, suggesting that less hot gas is present than required by these models. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Wilson, AS (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. NR 39 TC 18 Z9 18 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 1999 VL 513 IS 2 BP L115 EP L118 DI 10.1086/311923 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YJ UT WOS:000079816200007 ER PT J AU Yan, ZC Dalgarno, A AF Yan, ZC Dalgarno, A TI Third-order dispersion coefficients for H(1s)-H(1s) system SO MOLECULAR PHYSICS LA English DT Article ID ATOMS AB Third-order dispersion coefficients C-11, C-13, and C-15 are calculated using variational wavefunctions in Sturmian basis sets. An existing discrepancy in the literature is resolved. Also, second-order dispersion coefficients C-n are calculated with even n up to 16. C1 Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Yan, ZC (reprint author), Natl Res Council Canada, Steacie Inst Mol Sci, 100 Sussex Dr, Ottawa, ON K1A 0R6, Canada. RI Yan, Zong-Chao/F-6668-2014 NR 5 TC 13 Z9 13 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD MAR 10 PY 1999 VL 96 IS 5 BP 863 EP 865 DI 10.1080/002689799165251 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 177HV UT WOS:000079205300014 ER PT J AU Ortner, DJ Kimmerle, EH Diez, M AF Ortner, DJ Kimmerle, EH Diez, M TI Probable evidence of scurvy in subadults from archeological sites in Peru SO AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY LA English DT Article DE subadult scurvy; porotic lesions; hypertrophic lesions; Peru ID ANEMIA; BONE AB Subadult scurvy is not well documented in archeological human remains despite the existence of many biomedical references indicating that bone changes do occur in some cases and, because of this, should be observable in human burials. There are several potential reasons for this gap in our knowledge of scurvy. Not all children who suffered from scurvy died of the disease or from other causes when they had scurvy Scurvy may not leave characteristic bone changes in every case of the disease. Some of the pathological conditions associated with scurvy have been known for many years, but these features may be rare or difficult to differentiate from other pathological conditions. Recently a lesion of the skull has been described (Ortner and Ericksen [1997] International Journal of Osteoarchaeology 7:212-220) that is probably pathognomonic for scurvy specifically porous and sometimes hypertrophic lesions of the greater wing of the sphenoid, This lesion is bilateral and highly associated with evidence of inflammation at other anatomical sites in the skull. A survey of subadult skulls (N = 363) in the human skeletal collection from Peru at the National Museum of Natural History, Smithsonian Institution, reveals a prevalence of 10% of skulls that exhibit plausible evidence of scurvy. Some cases of scurvy also have cribra orbitalia that has been attributed to anemia. In most BE the Peruvian scurvy cases, anemia is an unlikely possibility because there is no evidence of marrow hyperplasia. This highlights the need for caution in using lesions of the orbit as an indicator of anemia when there is no other evidence of this disease elsewhere in the skeleton. Anatomical evidence of scurvy offers the potential of providing new and important evidence of diet in archeological human populations. (C) 1999 Wiley-Liss, Inc. C1 Smithsonian Inst, Dept Anthropol, Natl Museum Nat Hist, Washington, DC 20560 USA. Univ Bradford, Dept Archaeol Sci, Bradford BD7 1DP, W Yorkshire, England. Univ Nebraska, Dept Anthropol, Lincoln, NE 68508 USA. Amer Chiropract Assoc, Off Profess Dev & Res, Arlington, VA 22209 USA. RP Ortner, DJ (reprint author), Smithsonian Inst, Dept Anthropol, Natl Museum Nat Hist, Washington, DC 20560 USA. NR 16 TC 63 Z9 66 U1 3 U2 14 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0002-9483 J9 AM J PHYS ANTHROPOL JI Am. J. Phys. Anthropol. PD MAR PY 1999 VL 108 IS 3 BP 321 EP 331 DI 10.1002/(SICI)1096-8644(199903)108:3<321::AID-AJPA7>3.0.CO;2-7 PG 11 WC Anthropology; Evolutionary Biology SC Anthropology; Evolutionary Biology GA 173BX UT WOS:000078962100007 PM 10096683 ER PT J AU Wcislo, WT AF Wcislo, WT TI Transvestism hypothesis: a cross-sex source of morphological variation for the evolution of parasitism among sweat bees (Hymenoptera : Halictidae)? SO ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA LA English DT Article DE Paralictus asteris; social parasitism; brood parasitism; masculinization; phenocopy; sex transfer ID APIDAE AB Brood parasitism has evolved repeatedly in insects, and is especially diverse within bees. Little attention has been given to the evolution of structural modifications associated with parasitism, in contrast to behavior. Female parasitic bees tend to converge on a suite of characters, some of which may involve loss of characters associated with pollen-collecting or nest-making, whereas others may represent new characters used in a parasitic lifestyle. Certain external traits of female parasites resemble those of males, and this study compares the phenetic similarity of males and females of a social parasite, Paralictus asteris Mitchell, and its host, Lasioglossum (Dialictus) imitatum (Smith). Results are consistent with the hypothesis that some structural traits associated with parasitism may be derived from the expression of male-like traits in females. C1 Smithsonian Trop Res Inst, Balboa, Panama. RP Wcislo, WT (reprint author), Smithsonian Trop Res Inst, Unit 0948, APO, AA 34002 USA. EM WcisloW@tivoli.si.edu NR 36 TC 9 Z9 12 U1 1 U2 5 PU ENTOMOLOGICAL SOC AMER PI LANHAM PA 10001 DEREKWOOD LANE, STE 100, LANHAM, MD 20706-4876 USA SN 0013-8746 J9 ANN ENTOMOL SOC AM JI Ann. Entomol. Soc. Am. PD MAR PY 1999 VL 92 IS 2 BP 239 EP 242 PG 4 WC Entomology SC Entomology GA 182PA UT WOS:000079506300013 ER PT J AU Wilner, DJ Bourke, TL Ho, PTP Killeen, NEB Calabretta, M AF Wilner, DJ Bourke, TL Ho, PTP Killeen, NEB Calabretta, M TI A search for water masers in the gravitationally lensed quasars H1413+117 and MG 0414+0534 SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : nuclei; gravitational lensing; quasars : individual (H1413+117, MG 0414+0534); masers; radio emission lines ID ACTIVE GALACTIC NUCLEI; EMISSION; GALAXIES; MG-0414+0534; MEGAMASER; GAS AB We searched for 22 GHz water maser emission from two gravitationally lensed quasars, H1413+/-117 (the Cloverleaf) at z = 2.56 and MG 0414+0534 at z = 2.64, using the Australia Telescope Compact Array. Detections of CO emission at millimeter wavelengths from these systems provide the redshifts of the molecular components with high precision and suggest substantial reservoirs of molecular gas. The observations were made with similar to 750 km s(-1) of velocity coverage, enough to span the entire range of CO emission. No narrow water maser features were found in the observed bands in either source, though the sensitivities achieved were sufficient for detection if either (1) the water maser luminosity were substantially larger than found in nearby low-power active galactic nuclei (AGNs), which maser theory suggests is plausible, or (2) the water maser luminosity were typical of nearby detected AGNs but magnified by an extremely large factor, as might be the case near a lens caustic. The detection limits for a 1.5 km s(-1) channel correspond to isotropic maser luminosities of a few 1000(m/10)(-1) L., where m is the lensing magnification factor, values that are comparable to the most luminous AGN water masers in the local universe for m approximate to 10. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CSIRO, Australia Telescope Natl Facil, Epping, NSW 1710, Australia. RP Wilner, DJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 20 TC 5 Z9 5 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAR PY 1999 VL 117 IS 3 BP 1139 EP 1142 DI 10.1086/300795 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187KZ UT WOS:000079786900003 ER PT J AU Kleyna, J Geller, M Kenyon, S Kurtz, M AF Kleyna, J Geller, M Kenyon, S Kurtz, M TI Measuring the dark matter scale of Local Group dwarf spheroidals SO ASTRONOMICAL JOURNAL LA English DT Article DE dark matter; galaxies : dwarf; galaxies : individual (Ursa Minor Draco); Local Group ID TO-LIGHT RATIOS; URSA-MINOR; GALAXIES; DRACO; KINEMATICS; HALOS AB We reanalyze published Draco and Ursa Minor dwarf spheroidal (dSph) stellar velocity data. Previous studies of dSph stellar distributions have concentrated principally on the spatial distribution of stars or on computation of a global velocity dispersion. A detailed understanding of the spatial behavior of the velocity distribution, however, is necessary to distinguish among competing theories of dSph dynamics. Here we apply a maximum-likelihood technique to fit the set of individual velocity measurements to a global distribution. Rather than calculating mean local velocity dispersions in regions where the data are sparse, this technique has the advantage of using the velocity measurements individually. We confirm earlier findings of a radial falloff in the velocity distribution of UMi, which is consistent with a mass-follows-light (MFL) King model. We also confirm an apparent radial rise in the velocity dispersion of Draco. However, these data do not suffice to distinguish among extended halo and MFL models. Finally, we perform simulations to determine the number of additional observations required to clearly differentiate between different dynamical models. Only similar to 10-20 additional observations at 0.75 times the tidal radius would be required to distinguish clearly between an MFL distribution and an extended halo or disrupted remnant model with a flat or radially rising velocity dispersion. We describe a method for treating the effect of binary stars, which may be a source of contamination. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kleyna, J (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI KURTZ, Michael /B-3890-2009; OI Kenyon, Scott/0000-0003-0214-609X; Kurtz, Michael/0000-0002-6949-0090 NR 27 TC 13 Z9 13 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAR PY 1999 VL 117 IS 3 BP 1275 EP 1284 DI 10.1086/300756 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187KZ UT WOS:000079786900015 ER PT J AU Greiner, J Tovmassian, GH Di Stefano, R Prestwich, A Gonzalez-Riestra, R Szentasko, L Chavarria, C AF Greiner, J Tovmassian, GH Di Stefano, R Prestwich, A Gonzalez-Riestra, R Szentasko, L Chavarria, C TI Transient supersoft X-ray emission from V 751 Cygni during the optical low-state SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE accretion, accretion disks; stars : individual : HD 199178; stars : individual : V 751 Cyg; stars : novae, cataclysmic variables; X-rays : stars ID ACCRETING WHITE-DWARFS; LARGE MAGELLANIC CLOUD; ALL-SKY SURVEY; CATACLYSMIC VARIABLES; LOW-MASS; STARS; NOVAE; PERIOD; POPULATION; HYDROGEN AB We have observed V 751 Cyg with the ROSAT HRI in a target-of-opportunity mode during its recent optical low state and clearly detect it at a count rate of 0.015 cts s(-1). The X-ray intensity is a factor of 7-19 (depending on the exact X-ray spectral shape) higher than the upper Limit obtained with the ROSAT PSPC during the optical high state, thus suggesting an anti-correlation of X-ray and optical intensity. Spectral investigations suggest a very soft X-ray spectrum. We investigate archival IUE data of V 751 Cyg and derive a distance of V 751 Cyg of d approximate to 500 pc based on the extinction estimate of E(B - V)=0.25+/-0.05. This implies that the X-ray emission is very luminous, on the order of 10(34)-10(36) erg s(-1). We have obtained quasi-simultaneous optical photometry and spectroscopy. The spectrum during the optical low-state is characterized by a very blue continuum and the presence of strong emission lines of the Balmer series and HeI. Also, HeII 4686 Angstrom is clearly detected. We establish that V 751 Cyg is a transient supersoft X-ray source and speculate that other VY Sd stars may also be of similar type. C1 Inst Astrophys, D-14482 Potsdam, Germany. Univ Nacl Autonoma Mexico, Inst Astron, Observ Astron Nacl, Ensenada 22860, Baja California, Mexico. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Lab Astrofis Espacial & Fis Fundamental, E-28080 Madrid, Spain. RP Greiner, J (reprint author), Inst Astrophys, An Sternwarte 16, D-14482 Potsdam, Germany. EM jgreiner@aip.de NR 73 TC 33 Z9 33 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAR PY 1999 VL 343 IS 1 BP 183 EP 196 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 173LG UT WOS:000078981600030 ER PT J AU Nisini, B Benedettini, M Giannini, T Clegg, PE Di Giorgio, AM Leeks, SJ Liseau, R Lorenzetti, D Molinari, S Saraceno, P Spinoglio, L Tommasi, E White, GJ Smith, HA AF Nisini, B Benedettini, M Giannini, T Clegg, PE Di Giorgio, AM Leeks, SJ Liseau, R Lorenzetti, D Molinari, S Saraceno, P Spinoglio, L Tommasi, E White, GJ Smith, HA TI An investigation of the B335 region through far infrared spectroscopy with ISO SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : formation; ISM : B 335; ISM : HH 119; ISM : jets and outflows infrared : ISM : lines and bands ID LONG-WAVELENGTH SPECTROMETER; SMALL-SCALE STRUCTURE; BOK GLOBULE B335; STAR FORMATION; MOLECULAR OUTFLOWS; CLOUDS; EMISSION; OBJECTS; SHOCKS; DARK AB We present far infrared spectra of the B335 dark cloud region, obtained with the Long Wavelength Spectrometer (LWS) on-board the ISO satellite. Deep spectra were obtained towards the far infrared outflow exciting source, located in the B335 core, and on the three associated Herbig Hare (HH) objects HH119 A, B and C. In addition, a region of about 9' in RA and 4' in Dec. was mapped which covers the whole molecular outflow. [CII] 158 mu m emission was found to be uniformly distributed across the observed region, with the intensity expected for a photodissociation region excited by the average interstellar held. The [OI]63 mu m emission was detected only towards two out of the three HH objects and from the B335 FIR source; excitation from the high-velocity shocks responsible for the HH119 knots can account for the observed line intensity. CO line emission from the rotational levels J=15 to J=18 was detected only towards B335 FIR and can be modelled as arising in warm gas whose excitation temperature is in the range 150-800 K, located in a compact(similar to 10(-3) pc) and dense (n(H2) similar to 10(6) cm(-3)) region. If we assume that the CO J= 6-->5 line observed from the ground is also emitted from the same gas component, we derive for this component a temperature of 350 K and a density of 5.10(5) cm(-3). Current collapse models for the B335 core fail to predict the presence of such warm gas in the infalling source envelope, at the spatial scales implied by our model fit. It is likely that the molecular emission is excited in a low-velocity ( upsilon similar to 10 km s(-1)) non-dissociative-shock, originating at the base of the flow. C1 CNR, Ist Fis Spazio Interplanetario, Area Ric, I-00133 Rome, Italy. Osservatorio Astron Roma, I-00040 Monteporzio, Italy. Univ Rome La Sapienza, Ist Astron, I-00161 Rome, Italy. Univ London Queen Mary & Westfield Coll, Dept Phys, London E1 4NS, England. Stockholm Observ, S-13336 Saltsjobaden, Sweden. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. Agenzia Spaziale Italiana, Rome, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Nisini, B (reprint author), CNR, Ist Fis Spazio Interplanetario, Area Ric, Via Fosso Cavaliere, I-00133 Rome, Italy. EM bruni@taurus.ifsi.rm.cnr.it RI Molinari, Sergio/O-4095-2016; OI Molinari, Sergio/0000-0002-9826-7525; Giannini, Teresa/0000-0002-0224-096X; Spinoglio, Luigi/0000-0001-8840-1551; , Brunella Nisini/0000-0002-9190-0113 NR 35 TC 19 Z9 19 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAR PY 1999 VL 343 IS 1 BP 266 EP 272 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 173LG UT WOS:000078981600040 ER PT J AU Wilkes, BJ Kuraszkiewicz, J Green, PJ Mathur, S McDowell, JC AF Wilkes, BJ Kuraszkiewicz, J Green, PJ Mathur, S McDowell, JC TI Investigation of the relation between the spectral energy distributions and emission lines in low-redshift quasars SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; quasars : emission lines; quasars : general ID ACTIVE GALACTIC NUCLEI; X-RAY-SPECTRA; OPTICALLY SELECTED QUASARS; EXTRAGALACTIC RADIO-SOURCES; FE-II EMISSION; HOST GALAXIES; STELLAR OBJECTS; SEYFERT-1 GALAXIES; LOUD QUASARS; CONTINUUM AB We investigate the relations between the observed emission-line strengths, widths, and continuum properties of a sample of 41 low-redshift (z < 1) quasars for which contemporaneous IR/soft X-ray spectral energy distributions are available. This includes investigating correlations between optical and UV lines with both the luminosity and the shape of the quasars' continuum, as well as correlations between the various lines. The sample is heterogeneous, primarily selected on the existence of good-quality Einstein X-ray data, and includes Is radio-loud and 23 radio-quiet quasars. We find anticorrelations between the equivalent width and various UV luminosities (the Baldwin effect) for the Ly alpha and H beta lines and a marginal anticorrelation for C III]. Exclusion of narrow-line, low-luminosity active galactic nuclei reveals a significant Baldwin effect for the C rv and C III] lines. A significant anticorrelation of EW(C IV) with alpha(ox) is also present. We find no correlations between any lines and the X-ray luminosity or X-ray slope. The Fe II optical multiplet shows no simple relationship with luminosity or continuum slope; however, there is a tendency for objects with flat X-ray spectra and/or strong X-ray luminosities to have weak Fe II. Our data do not favor a model in which changes in continuum shape (due to, e.g., a decreasing ionization parameter) cause the Baldwin effect. The data can instead be explained by an accretion disk (AD) model in which limb darkening and the projected surface area of an optically thick, geometrically thin disk combine to cause a viewing-angle-dependent UV luminosity and a more isotropic X-ray luminosity. The scatter in our correlations is larger than that expected from this AD model, suggesting the presence of dust, which reddens both the continuum and the broad emission lines. The C Iv and C mi lines show flatter slopes and larger scatter in the line-continuum relations than predicted by the AD+dusty torus model. This may be due to a significant contribution from collisional excitation that is not directly related to the ionizing continuum. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. N Copernicus Astron Ctr, PL-00716 Warsaw, Poland. RP Wilkes, BJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Wilkes, Belinda/0000-0003-1809-2364 NR 96 TC 44 Z9 44 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1999 VL 513 IS 1 BP 76 EP 107 DI 10.1086/306828 PN 1 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194MM UT WOS:000080197500006 ER PT J AU Lee, CW Lee, HM Ann, HB Kwon, KH AF Lee, CW Lee, HM Ann, HB Kwon, KH TI Smoothed particle hydrodynamic simulations of galactic gaseous disk with bar: Distribution and kinematic structure of molecular clouds toward the galactic center SO ASTROPHYSICAL JOURNAL LA English DT Article ID GALAXIES; GAS; ROTATION; REGION; MODEL; BULGE; MASS AB We have performed smoothed particle hydrodynamic (SPH) simulations to study the response of molecular clouds in the Galactic disk to a rotating bar and their subsequent evolution in the Galactic center (GC) region. The Galactic potential in our models is contributed by three axisymmetric components (massive halo, exponential disk, compact bulge) and a nonaxisymmetric bar. These components are assumed to be invariant in time in the frame corotating with the bar. Some noticeable features such as an elliptical outer ring, spiral arms, a gas-depletion region, and a central concentration have been developed due to the influence of the bar. The rotating bar induces noncircular motions of the SPH particles, but hydrodynamic collisions tend to suppress the random components of the velocity. The velocity held of the SPH particles is consistent with the kinematics of molecular clouds observed in HCN (1-0) transition; these clouds are thought to be very dense clouds. However, the longitude-velocity (l-v) diagram of the clouds traced by CO is quite different from that of our SPH simulation, being more similar to that obtained from simulations using collisionless particles. The I-v diagram of a mixture of collisional and collisionless particles gives better reproduction of the kinematic structures of the GC clouds observed in the CO line. The fact that the kinematics of HCN clouds can be reproduced by the SPH particles suggests that the dense clouds in the GC are formed via cloud collisions induced by the rotating bar. C1 Pusan Natl Univ, Dept Earth Sci, Pusan 609735, South Korea. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Seoul Natl Univ, Dept Astron, Seoul 151742, South Korea. RP Lee, CW (reprint author), Pusan Natl Univ, Dept Earth Sci, Pusan 609735, South Korea. EM cwlee@cfa.harvard.edu; hmlee@astro.snu.ac.kr; hbann@astrophys.es.pusan.ac.kr; khkowen@astrophys.es.pusan.ac.kr NR 33 TC 19 Z9 19 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1999 VL 513 IS 1 BP 242 EP 251 DI 10.1086/306846 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194MM UT WOS:000080197500018 ER PT J AU Ostriker, EC Gammie, CF Stone, JM AF Ostriker, EC Gammie, CF Stone, JM TI Kinetic and structural evolution of self-gravitating, magnetized clouds: 2.5-dimensional simulations of decaying turbulence SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : general; ISM : kinematics and dynamics; ISM : magnetic fields; MHD; shock waves ID REGULATED STAR-FORMATION; MOLECULAR CLOUDS; HYDROMAGNETIC-WAVES; FORMING REGIONS; THERMAL BALANCE; FLOWS; OPHIUCHUS; POLARIZATION; COLLAPSE; DENSITY AB The molecular component of the Galaxy is comprised of turbulent, magnetized clouds, many of which are self-gravitating and form stars. To develop an understanding of how these clouds' kinetic and structural evolution may depend on their level of turbulence, mean magnetization, and degree of self-gravity, we perform a survey of direct numerical MHD simulations in which three parameters are independently varied. Our simulations consist of solutions to the time-dependent MI-ID equations on a two-dimensional grid with periodic boundary conditions; an additional "half" dimension is also incorporated as dependent variables in the third Cartesian direction. Two of our survey parameters, the mean magnetization parameter beta = c(sound)(2)/upsilon(Alfven)(2) and the Jeans number n(J) = L(cloud)/L(Jeans), allow us to model clouds that either meet or fail conditions for magneto-Jeans stability and magnetic criticality. Our third survey parameter, the sonic Mach number M = sigma(velocity)/c(sound), allows us to initiate turbulence of either sub- or super-Alfvenic amplitude; we employ an isothermal equation of state throughout. We evaluate the times for each cloud model to become gravitationally bound and measure each model's kinetic energy loss over the fluid-flow crossing time. We compare the evolution of density and magnetic field structural morphology and quantify the differences in the density contrast generated by internal stresses for models of differing mean magnetization. We find that the values of beta and n(J), but not the initial Mach number M, determine the time for cloud gravitational binding and collapse: for mean cloud density n(H2) = 100 cm(-3), unmagnetized models collapse after similar to 5 Myr, and magnetically supercritical models generally collapse after 5-10 Myr (although the smallest magneto-Jeans stable clouds survive gravitational collapse until t similar to 15 Myr), while magnetically subcritical clouds remain uncollapsed over the simulations; these cloud collapse times scale with the mean density as t(g) proportional to n(H2)(-1/2). We find, contrary to some previous expectations, less than a factor of 2 difference between turbulent decay times for models with varying magnetic field strength; the maximum decay time, for B similar to 14 mu G and n(H2) = 100 cm(-3), is 1.4 flow crossing times t(cross) =L/sigma(velocity) (or 8 Myr for typical giant molecular cloud cm parameters). In all models we find turbulent amplification in the magnetic field strength up to at least the level beta(pert) c(sound)(2)/delta upsilon(Alfven)(2) = 0.1. With the turbulent magnetic energy between 25% and 60% of the turbulent kinetic energy after one flow crossing time. We find that for non-self-gravitating stages of evolution, when clouds have M = 5-10, the mass-averaged density contrast magnitudes [log (rho/<(rho)over bar>)] are in the range 0.2-0.5, with the contrast increasing both toward low and high B. Although our conclusions about density statistics may be affected by our isothermal assumption, we note that only the more strongly magnetized models appear to be consistent with estimates of clump/interclump density contrasts inferred in Galactic giant molecular clouds. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Isaac Newton Inst Math Sci, Cambridge CB3 0EH, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Ostriker, EC (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NR 54 TC 138 Z9 138 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1999 VL 513 IS 1 BP 259 EP 274 DI 10.1086/306842 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194MM UT WOS:000080197500020 ER PT J AU McCarthy, MC Grabow, JU Travers, MJ Chen, W Gottlieb, CA Thaddeus, P AF McCarthy, MC Grabow, JU Travers, MJ Chen, W Gottlieb, CA Thaddeus, P TI Laboratory detection of the ring-chain carbenes HC4N and HC6N SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : molecules; line : identification; molecular data; molecular processes; radio lines : ISM ID MOLECULE; SPECTROSCOPY; C5H2 AB The highly polar ring-chain carbenes HC4N and HC6N, formed by substituting either CN or CCCN for a hydrogen atom in cyclopropenylidene (c-C3H2), were detected in a supersonic molecular beam with a Fourier transform microwave spectrometer. Seven a- and four b-type rotational transitions of HC4N and 11 a-type transitions of HC6N, each with resolved nitrogen nuclear quadrupole hyperfine structure, were measured between 6 and 21 GHz, yielding precise values for the three rotational constants, the leading centrifugal distortion constants, and the quadrupole coupling constants. Like the hydrocarbon carbenes C5H2, C7H2, and C9H2, both new molecules have a planar ring-chain structures and singlet electronic ground states. The strongest lines of HC4N can be detected with a signal-to-noise ratio exceeding 10 in a total integration time of less than 1 s, but the lines of HC6N were nearly 100 times weaker. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP McCarthy, MC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI McCarthy, Michael/0000-0001-9142-0008 NR 21 TC 22 Z9 23 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1999 VL 513 IS 1 BP 305 EP 310 DI 10.1086/306851 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194MM UT WOS:000080197500024 ER PT J AU Gayley, KG Owocki, SP Cranmer, SR AF Gayley, KG Owocki, SP Cranmer, SR TI Line-driven ablation and wind tilting by external irradiation SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; line : formation; stars : mass loss ID HOT-STAR WINDS; PURE ABSORPTION-MODEL; STELLAR WINDS; BINARY-SYSTEMS; DISK FORMATION; ROTATION AB The directional variation of the velocity gradient in a supersonic, radiatively accelerated flow gives an effectively anisotropic character to the line-scattering process. This leads to surprising consequences in source geometries that are more complex than isolated nonrotating stars. In this paper we explore the wind dynamics from a planar slab atmosphere that is irradiated by an external oblique source, within the framework of standard Castor, Abbott, & Klein (CAK) wind theory. We show that the presence of externally incident radiation can be surprisingly effective at tilting the how away from the vertical. Even more surprising is our conclusion that such illumination should often enhance the mass loss and can even induce outflow from a surface with no intrinsic radiation source. We examine the physical causes of such "line-driven ablation" and discuss the potential implications for modeling line-driven flows in massive-star binary and accretion-disk systems. C1 Univ Iowa, Iowa City, IA 52245 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Gayley, KG (reprint author), Univ Iowa, Iowa City, IA 52245 USA. NR 33 TC 18 Z9 18 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1999 VL 513 IS 1 BP 442 EP 459 DI 10.1086/306848 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194MM UT WOS:000080197500034 ER PT J AU Greeley, BW Blair, WP Long, KS Raymond, JC AF Greeley, BW Blair, WP Long, KS Raymond, JC TI The far-ultraviolet spectrum and short-timescale variability of AM Herculis from observations with the Hopkins Ultraviolet Telescope SO ASTROPHYSICAL JOURNAL LA English DT Article DE novae, cataclysmic variables; stars : individual (AM Herculis); stars : magnetic fields ID X-RAY EXCESS; WHITE-DWARF; OPTICAL VARIABILITY; CALIBRATION; ACCRETION; EMISSION; SYSTEM; SPECTROSCOPY; PERFORMANCE; RADIATION AB Using the Hopkins Ultraviolet Telescope (HUT), we have obtained 850-1850 Angstrom spectra of the magnetic cataclysmic variable star AM Her in the high state. These observations provide high time resolution spectra of AM Her in the far-ultraviolet and sample much of the orbital period of the system. The spectra are not well modeled in terms of simple white dwarf (WD) atmospheres, especially at wavelengths shortward of Ly alpha. The continuum flux changes by a factor of 2 near the Lyman limit as a function of orbital phase; the peak fluxes are observed near magnetic phase 0.6 when the accreting pole of the WD is most clearly visible. The spectrum of the hot spot can be modeled in terms of a 100,000 K WD atmosphere covering 2% of the WD surface. The high time resolution of the HUT data allows an analysis of the short-term variability and shows the UV luminosity to change by as much as 50% on timescales as short as 10 s. This rapid variability is shown to be inconsistent with the clumpy accretion model proposed to account for the soft X-ray excess in polars. We see an increase in narrow-line emission during these flares when the heated face of the secondary is in view. The He II narrow-line flux is partially eclipsed at secondary conjunction, implying that the inclination of the system is greater than 45 degrees. We also present results from models of the heated face of the secondary. These models show that reprocessing on the face of the secondary star of X-ray/EUV emission from the accretion region near the WD can account for the intensities and kinematics of most of the narrow-line components observed. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Greeley, BW (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NR 55 TC 15 Z9 15 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1999 VL 513 IS 1 BP 491 EP 505 DI 10.1086/306853 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194MM UT WOS:000080197500039 ER PT J AU Downes, D Neri, R Wiklind, T Wilner, DJ Shaver, PA AF Downes, D Neri, R Wiklind, T Wilner, DJ Shaver, PA TI Detection of CO (4-3), CO (9-8), and dust emission in the broad absorption line quasar APM 08279+5255 at a redshift of 3.9 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : ISM; gravitational lensing; quasars : individual (APM 08279+5255); radio lines : galaxies ID IRAS F10214+4724 AB With the IRAM interferometer, we detected the lines of CO (4-3) and CO (9-8) from the recently discovered broad absorption line quasar APM 08279+5255. The molecular lines are at a redshift of 3.911, which we take to be the true cosmological redshift of the quasar's host galaxy. This means that the quasar emission lines at 3.87 are blueshifted by a kinematic component of -2500 km s(-1) and, along with the broad absorption lines, are probably emitted in the quasar's wind or jet, moving toward us. The CO line ratios suggest that the molecular gas is at a temperature of similar to 200 K, at a density of similar to 4000 cm(-3). We also detected the dust emission at 94 and 214 GHz (with emitted wavelengths of 650 and 290 mu m). The spectral index of the millimeter/submillimeter continuum is 3.2, indicating that the dust emission is optically thin in this part of the spectrum. The extremely high CO and dust luminosities suggest magnification by gravitational lensing. Using the optical extent and our limit an the size of the CO region, we estimate a magnification of 7-30 for the CO lines and the far-IR continuum and 14-60 for the optical/UV. In this interpretation, the molecular gas and dust are in a nuclear disk of radius 90-270 pc around the quasar. The quasar is 25-100 times stronger than, but otherwise resembles, the nucleus of Mrk 231. C1 Inst Radio Astron Millimetr, F-38406 St Martin Dheres, France. Onsala Space Observ, S-43992 Onsala, Sweden. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. European So Observ, D-85648 Garching, Germany. RP Downes, D (reprint author), Inst Radio Astron Millimetr, F-38406 St Martin Dheres, France. NR 17 TC 82 Z9 82 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1999 VL 513 IS 1 BP L1 EP L4 DI 10.1086/311896 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194MN UT WOS:000080197600001 ER PT J AU Williams, JP Myers, PC Wilner, DJ Di Francesco, J AF Williams, JP Myers, PC Wilner, DJ Di Francesco, J TI A high-resolution study of the slowly contracting, starless core L1544 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (L1544); ISM : kinematics and dynamics; stars : formation ID CLOUD CORES; AMBIPOLAR DIFFUSION; PROTOSTARS; COLLAPSE AB We present interferometric observations of N2H+ (1-0) in the starless, dense core L1544 in Taurus. Redshifted self-absorption, indicative of inward motions, is found toward the center of an elongated core. The data are fit by a nonspherical model consisting of two isothermal, rotating, centrally condensed layers. Through a hybrid global-individual fit to the spectra, we map the variation of infall speed at scales similar to 1400 AU and find values similar to 0.08 km s(-1) around the core center. The inward motions are small in comparison to thermal, rotational, and gravitational speeds but are large enough to suggest that L1544 is very close to forming a star. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Williams, JP (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Williams, Jonathan/B-1643-2009; OI Williams, Jonathan/0000-0001-5058-695X NR 15 TC 80 Z9 80 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1999 VL 513 IS 1 BP L61 EP L64 DI 10.1086/311895 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 194MN UT WOS:000080197600016 ER PT J AU Goldsworthy, SD Boness, DJ Fleischer, RC AF Goldsworthy, SD Boness, DJ Fleischer, RC TI Mate choice among sympatric fur seals: female preference for conphenotypic males SO BEHAVIORAL ECOLOGY AND SOCIOBIOLOGY LA English DT Article DE mate choice; mating success; hybridization; DNA fingerprinting; mitochondrial DNA; fur seal; Arctocephalus spp. ID POSTMATING REPRODUCTIVE ISOLATION; PRINCE-EDWARD-ISLANDS; MALE MATING SUCCESS; ARCTOCEPHALUS-TROPICALIS; GENETIC-VARIATION; SOUTH-GEORGIA; GRAY SEAL; SPECIATION; DROSOPHILA; GAZELLA AB When closely related species breed in sympatry, and where hybrids have lower fitness, reinforcement theory predicts that selection should favour mechanisms that reduce the probability of interspecific matings. If this situation arises among species that exhibit resource defence polygyny where males and females of different species reside in the same territories, there may be some conflict between mate choice based on territory-holding ability (sexual selection) and mate choice for correct species. We investigated this in a population of fur seals where three species are sympatric and where some females breed in the territories of heterospecific males, and where interspecific matings and hybrid pups are observed. The territorial status of males and the birthing sites of females were determined during daily observations, as were the movements of males and females, the location of matings and mating partners. DNA extracted from skin samples was used to determine paternities using DNA fingerprinting and the mtDNA genotype of individuals. Individuals were also classed on the basis of species-typical phenotype. We found that extra-territory inseminations (ETIs) were significantly more prevalent (67%) when territorial males and resident females were of different phenotype than when of similar phenotype (27%), but mtDNA genotype had no effect on the rate of ETIs. ETIs were probably by males with the same phenotype, as pups born to these females in the following season had the same phenotype as their mothers, suggesting they were not hybrids. These results suggest that within the resource defence polygynous mating system of these sympatric fur seals, female mate choice is more influenced by male phenotype than genotype. Contrary to our predictions, our study indicates that potential conflict between mate choice based on sexual selection and species recognition is unlikely, because Females have some capacity to discriminate between males both within and between species on phenotypic traits additional to those under sexual selection. Although at least 25% of the pups born in this study were hybrid, this study can only support reinforcement theory if hybrids have reduced fitness. The fitness of hybrids among the species studied is currently unknown. C1 Smithsonian Inst, Natl Zool Pk, Dept Zool Res, Washington, DC 20008 USA. RP Goldsworthy, SD (reprint author), Univ Tasmania, Dept Zool, POB 252-05, Hobart, Tas 7001, Australia. EM simon.goldsworthy@zoo.utas.edu.au NR 60 TC 37 Z9 38 U1 2 U2 10 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0340-5443 J9 BEHAV ECOL SOCIOBIOL JI Behav. Ecol. Sociobiol. PD MAR PY 1999 VL 45 IS 3-4 BP 253 EP 267 DI 10.1007/s002650050560 PG 15 WC Behavioral Sciences; Ecology; Zoology SC Behavioral Sciences; Environmental Sciences & Ecology; Zoology GA 182VT UT WOS:000079519400012 ER PT J AU Roberts, RL Wolf, KN Sprangel, ME Rall, WF Wildt, DE AF Roberts, RL Wolf, KN Sprangel, ME Rall, WF Wildt, DE TI Prolonged mating in prairie voles (Microtus ochrogaster) increases likelihood of ovulation and embryo number SO BIOLOGY OF REPRODUCTION LA English DT Article ID SEXUAL-BEHAVIOR; FEMALE; HORMONE; ESTRUS AB Prairie voles are induced ovulators that mate frequently in brief bouts over a period of similar to 24 h. We examined 1) impact of mating duration on ovulation and embryo number, 2) incidence of fertilization, 3) temporal pattern of embryo development, 4) embryo progression through the reproductive tract over time, and 5) embryo development in culture. Mating was videotaped to determine first copulation, and the ovaries were examined and the reproductive tracts flushed at 6, 8, 10, 12, 16, 20, and 24 h and 2, 3, and 4 days after first copulation. The number of mature follicles and fresh corpora lutea and the number and developmental stage of embryos were quantified. One, two-, and four-cell embryos were cultured in Whitten's medium. Mature follicles were present at the earliest time examined (6 h). Thirty-eight percent of females that had been paired for < 12 h after the first copulation ovulated, whereas all females paired greater than or equal to 12 h after the first copulation ovulated. Virtually all (> 99%) oocytes recovered from females paired for greater than or equal to 12 h after first copulation were fertilized. Pairing time after first copulation and mean copulation-bout duration were significant (p < 0.05) determinants of embryo number. Embryos entered the uterine horns and implanted on Days 3 and 4, respectively, after first copulation (Day 0). Embryos cultured in vitro underwent approximately one cell division per day, a rate similar to that in vivo. We conclude that prairie voles ovulate reliably after pairing for greater than or equal to 72 h, although some females showed exceptional sensitivity not predicted by the variables quantified. Prolonged mating for longer than 12 h increased the total embryos produced. This mechanism likely has adaptive significance for increasing offspring number. C1 Smithsonian Inst, Natl Zool Pk, Reprod Physiol Program, Washington, DC 20008 USA. Smithsonian Inst, Natl Zool Pk, Conservat & Res Ctr, Front Royal, VA 22630 USA. NIH, Vet Resources Program, Off Res Serv, Bethesda, MD 20892 USA. RP Roberts, RL (reprint author), NICHHD, Comparat Ethol Lab, POB 529,16701 Elmer Sch Rd, Poolesville, MD 20837 USA. EM lr123g@nih.gov RI Rall, William/C-5104-2008 NR 24 TC 18 Z9 18 U1 2 U2 4 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 USA SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD MAR PY 1999 VL 60 IS 3 BP 756 EP 762 DI 10.1095/biolreprod60.3.756 PG 7 WC Reproductive Biology SC Reproductive Biology GA 170RY UT WOS:000078820900032 PM 10026127 ER PT J AU Peitz, J Appl, S AF Peitz, J Appl, S TI Dissipative fluid dynamics in the 3+1 formalism SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID RELATIVISTIC THERMODYNAMICS; EQUATIONS AB Non-ideal relativistic hydrodynamics is formulated with respect to fiducial observers (FIDOs). Three types of theories for dissipative relativistic fluids are considered, which have different causality properties. and different complexity of the equations that determine the dissipative fluxes. The 3 + 1 equations for these fluid theories are given in terms of the 3-space quantities which correspond to those familiar from non-relativistic physics. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Heidelberg, Inst Angew Math, D-69120 Heidelberg, Germany. RP Peitz, J (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 21 TC 3 Z9 3 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD MAR PY 1999 VL 16 IS 3 BP 979 EP 989 DI 10.1088/0264-9381/16/3/025 PG 11 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 180TA UT WOS:000079400200024 ER PT J AU Erwin, TL Kavanaugh, DH AF Erwin, TL Kavanaugh, DH TI Studies of the subtribe tachyina (Coleoptera : Carabidae : Bembidiini), supplement D: Description of a male of Costitachys inusitatus Erwin, with notes on distribution of this species SO COLEOPTERISTS BULLETIN LA English DT Article AB Newly discovered specimens of Costitachys inusitatus Erwin provide characters of the male, heretofore unknown, and extend the range beyond the type locality into two biogeographic regions of South America, the "North Atlantic Coast" and "Lower Amazon-Mid-Atlantic Coast." Male characters provide little additional information useful in establishing relationships of this remarkably distinctive species, although they affirm its position among the higher Tachyina. C1 US Natl Museum Nat Hist, Dept Entomol, Smithsonian Inst, Washington, DC 20560 USA. RP Erwin, TL (reprint author), US Natl Museum Nat Hist, Dept Entomol, Smithsonian Inst, Washington, DC 20560 USA. NR 4 TC 1 Z9 2 U1 0 U2 0 PU COLEOPTERISTS SOC PI NATCHEZ PA P.O. BOX 767, NATCHEZ, MS 39121 USA SN 0010-065X J9 COLEOPTS BULL JI Coleopt. Bull. PD MAR PY 1999 VL 53 IS 1 BP 52 EP 55 PG 4 WC Entomology SC Entomology GA 188TW UT WOS:000079865400007 ER PT J AU Rupprecht, CS Schmidt, D AF Rupprecht, CS Schmidt, D TI On interdisciplinarity: An essay for the special issue SO DREAMING LA English DT Article C1 Hamilton Coll, Dept Comparat Literature, Clinton, NY 13323 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Rupprecht, CS (reprint author), Hamilton Coll, Dept Comparat Literature, Clinton, NY 13323 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC-HUMAN SCIENCES PRESS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 1053-0797 J9 DREAMING JI Dreaming PD MAR PY 1999 VL 9 IS 1 BP 3 EP 9 DI 10.1023/A:1021360808986 PG 7 WC Psychology, Multidisciplinary SC Psychology GA 171UK UT WOS:000078882300002 ER PT J AU Schmidt, D AF Schmidt, D TI Stretched dream science: The essential contribution of long-term naturalistic studies SO DREAMING LA English DT Article DE naturalistic dream study; longitudinal dream study; philosophy of science AB Naturalistic observation has a lesser status than experiment in most sciences. In the field of dream study, practitioners of naturalistic and experimental disciplines coexist, with limited mutual respect. Long-term naturalistic observation, though, has unique sensitivities that make it the most effective or the only possible method for many important studies. While there are challenges to integrating naturalistic and experimental disciplines, there are possibilities, and there is a scientific imperative. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Schmidt, D (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 61 TC 1 Z9 1 U1 1 U2 2 PU KLUWER ACADEMIC-HUMAN SCIENCES PRESS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 1053-0797 J9 DREAMING JI Dreaming PD MAR PY 1999 VL 9 IS 1 BP 43 EP 69 DI 10.1023/A:1021317026733 PG 27 WC Psychology, Multidisciplinary SC Psychology GA 171UK UT WOS:000078882300005 ER PT J AU Krombein, KV AF Krombein, KV TI Taxonomic notes on Eusapyga (Hymenoptera : Sapygidae) and description of Eusapyga nordenae n. sp. SO ENTOMOLOGICAL NEWS LA English DT Article AB Variation is reported in the number of ocellar calli in Eusapyga and linear tyloids are noted ventrally on the terminal flagellomeres of males. Eusapyga nordenae, n. sp., is described from south central Florida sand scrub. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, Washington, DC 20560 USA. RP Krombein, KV (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, Washington, DC 20560 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER ENTOMOL SOC PI PHILADELPHIA PA 1900 BENJ FRANKLIN PARKWAY, PHILADELPHIA, PA 19103-1195 USA SN 0013-872X J9 ENTOMOL NEWS JI Entomol. News PD MAR-APR PY 1999 VL 110 IS 2 BP 89 EP 91 PG 3 WC Entomology SC Entomology GA 193PP UT WOS:000080145500003 ER PT J AU Burch, ES Jones, E Loon, HP Kaplan, LD AF Burch, ES Jones, E Loon, HP Kaplan, LD TI The ethnogenesis of the Kuuvaum Kaniagmiut SO ETHNOHISTORY LA English DT Article AB The Native inhabitants of the upper Kobuk River, Alaska, are identified in the ethnographic record as Inupiaq Eskimos. This article presents evidence showing that they were actually Koyukon-speaking Athapaskans in the early nineteenth century. Between about I86o and I88o they were rapidly and peacefully assimilated, and they are Inupiaq Eskimos today. C1 Smithsonian Inst, Washington, DC 20560 USA. Univ Alaska, Fairbanks, AK 99701 USA. RP Burch, ES (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 82 TC 4 Z9 4 U1 0 U2 1 PU DUKE UNIV PRESS PI DURHAM PA 905 W MAIN ST, STE 18-B, DURHAM, NC 27701 USA SN 0014-1801 J9 ETHNOHISTORY JI Ethnohistory PD SPR PY 1999 VL 46 IS 2 BP 291 EP 327 PG 37 WC Anthropology; History SC Anthropology; History GA 199WH UT WOS:000080506700004 ER PT J AU Bilby, K AF Bilby, K TI 'Roots explosion': Indigenization and cosmopolitanism in contemporary Surinamese popular music SO ETHNOMUSICOLOGY LA English DT Article ID WORLD MUSIC; IDENTITY; INDUSTRY; CULTURE; SOUTH; BEAT; VIEW C1 Smithsonian Inst, Washington, DC 20560 USA. RP Bilby, K (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 95 TC 22 Z9 22 U1 1 U2 2 PU SOC ETHNOMUSICOLOGY INC PI BLOOMINGTON PA MORRISON HALL, ROOM 005 INDIANA UNIVERSITY, BLOOMINGTON, IN 47405 USA SN 0014-1836 J9 ETHNOMUSICOLOGY JI Ethnomusicology PD SPR-SUM PY 1999 VL 43 IS 2 BP 256 EP 296 DI 10.2307/852735 PG 41 WC Music SC Music GA 211BD UT WOS:000081139300003 ER PT J AU Seeger, A AF Seeger, A TI The didjeridu: From Arnhem Land to internet SO ETHNOMUSICOLOGY LA English DT Book Review C1 Smithsonian Inst, Smithsonian Folkways, Washington, DC 20560 USA. RP Seeger, A (reprint author), Smithsonian Inst, Smithsonian Folkways, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SOC ETHNOMUSICOLOGY INC PI BLOOMINGTON PA MORRISON HALL, ROOM 005 INDIANA UNIVERSITY, BLOOMINGTON, IN 47405 USA SN 0014-1836 J9 ETHNOMUSICOLOGY JI Ethnomusicology PD SPR-SUM PY 1999 VL 43 IS 2 BP 367 EP 369 DI 10.2307/852747 PG 3 WC Music SC Music GA 211BD UT WOS:000081139300016 ER PT J AU Wang, JH Davis, AM Clayton, RN Hashimoto, A AF Wang, JH Davis, AM Clayton, RN Hashimoto, A TI Evaporation of single crystal forsterite: Evaporation kinetics, magnesium isotope fractionation, and implications of mass-dependent isotopic fractionation of a diffusion-controlled reservoir SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID EARLY SOLAR NEBULA; ALLENDE METEORITE; CATION DIFFUSION; OXYGEN FUGACITY; SELF-DIFFUSION; OLIVINE; INCLUSIONS; CONDENSATION; SYSTEM; CREEP AB Single crystals of forsterite were evaporated in a vacuum furnace at temperatures of 1500-1800 degrees C to study evaporation kinetics, magnesium isotopic fractionation, and magnesium diffusion in forsterite. The evaporation of single crystal forsterite revealed that the evaporation process is kinetically hindered, in agreement with the results of Hashimoto (1990) on polycrystalline forsterite. The activation energy of forsterite evaporation obtained from this study is 628 kJ/mole. Forsterite can thus be much more refractory at low temperatures than expected from thermodynamic predictions. The evaporation of solid forsterite supports a model of isotopic fractionation under diffusion-controlled conditions such that isotopic fractionation during the evaporation process is restricted to the vicinity of the evaporating surface. The measured solid-gas fractionation factor of Mg-26/Mg-24 is Smaller than the theoretical prediction, suggesting more complicated gas speciation than a monatomic Mg gas. Diffusion coefficients of forsterite at high temperature (1500-1800 degrees C) were obtained based on measurement of isotopic proAles in the evaporation residues. Mg diffusion in forsterite along its crystallographic a-axis has a very high activation energy (608 kJ/mole). Copyright (C) 1999 Elsevier Science Ltd. C1 Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Wang, JH (reprint author), Carnegie Inst Washington, Dept Terr Magnetism, 5241 Broad Branch Rd NW, Washington, DC 20015 USA. RI Wang, Jianhua/D-6500-2011; OI Wang, Jianhua/0000-0002-7671-2413; Davis, Andrew/0000-0001-7955-6236 NR 63 TC 54 Z9 54 U1 4 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAR PY 1999 VL 63 IS 6 BP 953 EP 966 DI 10.1016/S0016-7037(98)00286-5 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 210GP UT WOS:000081097000015 ER PT J AU Mudar, KM AF Mudar, KM TI How many Dvaravati kingdoms? Locational analysis of first millennium AD moated settlements in central Thailand SO JOURNAL OF ANTHROPOLOGICAL ARCHAEOLOGY LA English DT Article; Proceedings Paper CT Session on Landscapes of Power - Regional Perspectives on States in Asia, at the 92nd Annual Meeting of the American-Anthropological-Association CY 1993 CL WASHINGTON, D.C. SP Amer Anthropol Assoc DE Southeast Asia; locational analysis; state-level polities ID SOUTHEAST-ASIA AB Locational information about moated settlements derived from examination of aerial photographs of central Thailand is used to assess the degree of regional integration and political centralization during the sixth to ninth centuries A.D. around the Bay of Bangkok A consideration of settlement size hierarchy, rank-size distribution, and geographical location suggests that the moated settlements were integrated into a single regional economic system by the end of the time under consideration. While it is argued that the moated settlements represent remnants of administrative hierarchy, it is unclear from the current data whether a single state-level polity or a series of smaller competing polities were present. Further investigation is needed to comprehend how the inhabitants of this region, who shared a common material culture and symbolic system, conceptualized their political relationships. (C) 1999 Academic Press. C1 Smithsonian Inst, Natl Museum Nat Hist, Repatriat Off, MRC 138,NHB, Washington, DC 20566 USA. RP Mudar, KM (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Repatriat Off, MRC 138,NHB, Washington, DC 20566 USA. NR 57 TC 13 Z9 13 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0278-4165 J9 J ANTHROPOL ARCHAEOL JI J. Anthropol. Archaeol. PD MAR PY 1999 VL 18 IS 1 BP 1 EP 28 DI 10.1006/jaar.1998.0329 PG 28 WC Anthropology; Archaeology SC Anthropology; Archaeology GA 173BW UT WOS:000078962000001 ER PT J AU Petraglia, M LaPorta, P Paddayya, K AF Petraglia, M LaPorta, P Paddayya, K TI The first Acheulian quarry in India: Stone tool manufacture, biface morphology, and behaviors SO JOURNAL OF ANTHROPOLOGICAL RESEARCH LA English DT Article ID SCRAPER MORPHOLOGY; NEELEY; BARTON; FORM AB An Acheulian quarry was recently identified in the Hunsgi Valley, India. An Acheulian quarry has never been described before on the Indian subcontinent and this is a site type that has rarely been investigated anywhere in the Old World. The Isampur quarry is at a siliceous limestone bedrock source. Surface survey and test excavations have revealed Acheulian assemblages, including a high density of chipped stone waste (i.e., cores, flakes, chunks), bifacial fools (i,e., bifaces, cleavers), and hammerstones, Petrofabric analysis of the limestone beds and study of artifact attributes indicate that hominids practiced standardized biface manufacturing methods at this quarry. Handaxes were made parallel to moderately thick tabular slabs the handaxe tips and butts often intersecting with joints. Cleavers were made on side-struck flakes from thick cores, which were derived from the thickest limestone beds. The dorsal surface of the side-struck cleavers was often subparallel to a bedding plane, and the bit was inclined into a cleavage scar or joint. The steps involved in biface manufacture prior to and during the reduction process indicate that a significant degree of planning was employed an important observation given our lack of understanding Middle Pleistocene hominid cognition. Repeated manufacture of certain tool types and discard of minimally retouched bifaces across the valley floors indicate relations between raw materials and behaviors that we do not yet fully comprehend. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Anthropol, Washington, DC 20560 USA. CUNY, Dept Earth & Environm Sci, New York, NY 10036 USA. Deccan Coll, Dept Archaeol, Pune 411006, Maharashtra, India. RP Petraglia, M (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Anthropol, Washington, DC 20560 USA. NR 57 TC 39 Z9 40 U1 1 U2 5 PU UNIV NEW MEXICO PI ALBUQUERQUE PA DEPT ANTHROPOLOGY, ALBUQUERQUE, NM 87131-1561 USA SN 0091-7710 J9 J ANTHROPOL RES JI J. Anthropol. Res. PD SPR PY 1999 VL 55 IS 1 BP 39 EP 70 PG 32 WC Anthropology SC Anthropology GA 187QB UT WOS:000079797200002 ER PT J AU Vencl, FV Morton, TC Mumma, RO Schultz, JC AF Vencl, FV Morton, TC Mumma, RO Schultz, JC TI Shield defense of a larval tortoise beetle SO JOURNAL OF CHEMICAL ECOLOGY LA English DT Article DE Plagiometriona clavata; Lema trilinea; Solanum; steroidal ID SOLANUM GLYCOALKALOIDS AB Larvae of the folivorous tortoise beetle, Plagiometriona clavata, carry shields formed from feces and exuviae above their bodies. We used an ecologically relevant predatory ant, Formica subsericea, in a bioassay to deter mine if shields functioned as simple barriers, as previous studies indicated, or whether they were chemical defenses. Shields were necessary for larval survival; shield removal rendered larvae vulnerable. Shields produced by larvae reared on a substitute diet failed to provide protection. Solvent-leached shields also failed to deter ants, indicating the shield had a host-derived chemical component likely located in the feces, not in the exuviae. Solanum dulcamara, the larval host plant, contained free phytol, steroidal glycoalkaloids, and saponins. Shields contained partially deglycosylated metabolites of host steroidal glycoalkaloids and saponins, a suite of fatty acids, and derivatives of phytol, which together formed a deterrent barrier against ant attack. We compared the mobile shield of P. clavata to the stationary shield of another S dulcamara-feeding leaf beetle, Lema trilinea. Both larval shield defenses were formed from a very similar array of host-derived compounds with deterrent properties. We concluded that convergent patterns of limited chemical transformation and selective incorporation of particular deterrent metabolites in shield defenses of two unrelated taxa represented responses to selection from invertebrate predators. C1 SUNY Stony Brook, Dept Neurobiol & Behav, Stony Brook, NY 11794 USA. Smithsonian Trop Res Inst, Balboa, Ancon, Panama. Univ Chicago, Dept Ecol & Evolut, Chicago, IL 60637 USA. Penn State Univ, Dept Entomol, University Pk, PA 16802 USA. RP Vencl, FV (reprint author), SUNY Stony Brook, Dept Neurobiol & Behav, Stony Brook, NY 11794 USA. RI Morton, Timothy /A-6266-2013; OI Morton, Timothy /0000-0002-1310-3450; Schultz, Jack/0000-0001-9870-3537 NR 48 TC 34 Z9 37 U1 2 U2 14 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0098-0331 J9 J CHEM ECOL JI J. Chem. Ecol. PD MAR PY 1999 VL 25 IS 3 BP 549 EP 566 DI 10.1023/A:1020905920952 PG 18 WC Biochemistry & Molecular Biology; Ecology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology GA 178PZ UT WOS:000079276200010 ER PT J AU Stanley, DJ AF Stanley, DJ TI Evaluating use of rock-hewn features for sea level measurement, Israeli coast SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE archaeological sites; eustatic sea level; historic time; Holocene; Israeli coast; kurkar; Mediterranean; neotectonics; piscinas; relative sea-level; rock-cut pools ID MEDITERRANEAN COAST; NORTHERN ISRAEL; HOLOCENE; TECTONICS; MOVEMENTS; CAESAREA; WELLS AB Israel's Mediterranean coast, positioned on a structurally active margin, shifted vertically to some extent during the late Holocene. Consequently, changes of relative sea-level that account for both eustatic sea level and land motion are subtle and generally difficult to measure. This study evaluates the value of pools and other anthropogenic rock-cut features used to measure changes of sea level during the late Holocene. A number of these depressions, originally formed to retain fish and for other purposes, still function at present sea level. Most rock-hewn pools and channels on the Israeli margin have been dated to Roman, Byzantine and Crusader periods, usually through indirect association with archaeological sites and other structures in the vicinity. In fact only a few of these features, such as the piscina at Caesarea with affixed mosaics, are accurately dated. It is proposed here that some rock-cut features on broad flat platforms, or trottoirs, at elevations close to present sea level, were formed in more recent time, possibly in association with quarry operations and removal of coastal rock material for construction during the past few centuries. Unless a rock-cut feature can be reliably dated, it should not be used to determine sea level or land motion on this geologically complex margin. C1 Smithsonian Inst, Deltas Global Change Program, Washington, DC 20560 USA. RP Stanley, DJ (reprint author), Smithsonian Inst, Deltas Global Change Program, E-206 NMNH, Washington, DC 20560 USA. NR 36 TC 5 Z9 5 U1 0 U2 1 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD SPR PY 1999 VL 15 IS 2 BP 326 EP 331 PG 6 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA 183RP UT WOS:000079567500003 ER PT J AU Gunderson, JH Goss, SH Coats, DW AF Gunderson, JH Goss, SH Coats, DW TI The phylogenetic position of Amoebophrya sp infecting Gymnodinium sanguineum SO JOURNAL OF EUKARYOTIC MICROBIOLOGY LA English DT Article DE dinoflagellate; rRNA; Syndiniophyceae ID SUBUNIT RIBOSOMAL-RNA; CHESAPEAKE BAY; GENE-SEQUENCES; DNA AB The small-subunit rRNA sequence of a species of Amoebophrya infecting Gymnodinium sanguineum in Chesapeake Bay was obtained and compared to the small subunit rRNA sequences of other protists. Phylogenetic trees constructed with the new sequence place Amoebophrya between the remaining dinoflagellates and ether protists. C1 Tennessee Technol Univ, Ctr Management Utilizat & Protect Water Resources, Cookeville, TN 38505 USA. Tennessee Technol Univ, Dept Biol, Cookeville, TN 38505 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Gunderson, JH (reprint author), Tennessee Technol Univ, Ctr Management Utilizat & Protect Water Resources, POB 5033, Cookeville, TN 38505 USA. EM JGUNDERSON@tntech.edu NR 18 TC 41 Z9 43 U1 1 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1066-5234 EI 1550-7408 J9 J EUKARYOT MICROBIOL JI J. Eukaryot. Microbiol. PD MAR-APR PY 1999 VL 46 IS 2 BP 194 EP 197 DI 10.1111/j.1550-7408.1999.tb04603.x PG 4 WC Microbiology SC Microbiology GA 200QA UT WOS:000080550300013 PM 10361739 ER PT J AU Koulianos, S Schmid-Hempel, R Roubik, DW Schmid-Hempel, P AF Koulianos, S Schmid-Hempel, R Roubik, DW Schmid-Hempel, P TI Phylogenetic relationships within the corbiculate Apinae (Hymenoptera) and the evolution of eusociality SO JOURNAL OF EVOLUTIONARY BIOLOGY LA English DT Article DE Apinae; cytochrome b; eusociality; mitochondrial DNA; phylogeny ID MOLECULAR PHYLOGENY; BEES; SEQUENCE; TREES AB We provide a comparison of 520 base pairs of the mitochondrial cytochrome b gene from exemplars of the Meliponini, the Apini, the Bombini and the Euglossini to determine the phylogenetic relationships within the corbiculate Apinae. Our results strongly suggest (91-97% according to bootstrap resampling) that the Meliponini and the Bombini are sister groups. This finding agrees with those of other molecular studies, but is discordant with previous hypotheses based on morphology and the combination of molecular and morphological data. If the Bombini and Meliponini are sister groups and reversal of advanced eusociality is unlikely, then advanced eusociality arose twice within this clade. However, ii reversion of eusociality occurred, then it is nor possible to discriminate between single or dual origins of advanced eusociality within this group. C1 ETH Zentrum NW, CH-8092 Zurich, Switzerland. Smithsonian Trop Res Inst, Unit 0948, APO, AA 34002 USA. RP Koulianos, S (reprint author), ETH Zentrum NW, CH-8092 Zurich, Switzerland. NR 31 TC 33 Z9 33 U1 0 U2 11 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1010-061X J9 J EVOLUTION BIOL JI J. Evol. Biol. PD MAR PY 1999 VL 12 IS 2 BP 380 EP 384 PG 5 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 175PW UT WOS:000079104400017 ER PT J AU Park, K Zink, LR Chance, KV Evenson, KM Nolt, IG AF Park, K Zink, LR Chance, KV Evenson, KM Nolt, IG TI Pressure broadening of the 118.455 cm(-1) rotational lines of OH by N-2, O-2, H-2, and He SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article AB We measured the pressure broadening of the 118.455cm(-1) (3.551Thz) rotational lines of OH by H-2, He, N-2 and O-2 From these measurements, we calculated the pressure broadening of this line by air. The broadening coefficients are 6.06(16) and 10.13(25) x 10(-7) cm(-1) Pa-1 at 296 and 194 K. We also measured the position of the manifold of lines, with results that are in excellent agreement with a previous accurate determination. The frequency of the strongest component of the transition (F = 4 <-- 3), and its 2 sigma uncertainty is 3551185.32(3) MHz. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Oregon, Dept Phys, Eugene, OR 97403 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Park, K (reprint author), Univ Oregon, Dept Phys, Eugene, OR 97403 USA. OI Chance, Kelly/0000-0002-7339-7577 NR 6 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD MAR PY 1999 VL 61 IS 5 BP 715 EP 716 DI 10.1016/S0022-4073(98)00057-0 PG 2 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 163UE UT WOS:000078424100016 ER PT J AU Ortner, DJ AF Ortner, DJ TI Bioarchaeology: interpreting behavior from the human skeleton SO JOURNAL OF THE ROYAL ANTHROPOLOGICAL INSTITUTE LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Ortner, DJ (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 1 U2 2 PU ROYAL ANTHROPOLOGICAL INST PI LONDON PA 50 FITZROY STREET, LONDON, ENGLAND W1P 5HS SN 1359-0987 J9 J ROY ANTHROPOL INST JI J. R. Anthropol. Inst. PD MAR PY 1999 VL 5 IS 1 BP 106 EP 107 DI 10.2307/2660972 PG 2 WC Anthropology SC Anthropology GA 193UG UT WOS:000080155100015 ER PT J AU Meggers, BJ AF Meggers, BJ TI In the society of nature: a native ecology in Amazonia SO JOURNAL OF THE ROYAL ANTHROPOLOGICAL INSTITUTE LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Meggers, BJ (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU ROYAL ANTHROPOLOGICAL INST PI LONDON PA 50 FITZROY STREET, LONDON, ENGLAND W1P 5HS SN 1359-0987 J9 J ROY ANTHROPOL INST JI J. R. Anthropol. Inst. PD MAR PY 1999 VL 5 IS 1 BP 119 EP 120 DI 10.2307/2660986 PG 2 WC Anthropology SC Anthropology GA 193UG UT WOS:000080155100029 ER PT J AU Poulin, B Wright, SJ Lefebvre, G Calderon, O AF Poulin, B Wright, SJ Lefebvre, G Calderon, O TI Interspecific synchrony and asynchrony in the fruiting phenologies of congeneric bird-dispersed plants in Panama SO JOURNAL OF TROPICAL ECOLOGY LA English DT Article DE competition; diet diversity; frugivorous birds; fruiting phenology; Miconia; Panama; Psychotria; seed dispersal ID TEMPORAL VARIATION; TROPICAL FORESTS; SEED DISPERSAL; COSTA-RICA; COMPETITION; POLLINATORS; EVOLUTION; COMMUNITY; PATTERNS; MIGRANT AB Plants potentially compete for seed dispersal. Selection may favour temporally segregated fruiting phenologies to minimize this competition and also to maintain resident populations of dispersal agents. Alternatively, selection may favour temporally aggregated fruiting phenologies when the effectiveness of seed dispersal agents varies seasonally or when large, synchronous fruit displays enhance dispersal. These evolutionary scenarios assume that plants share seed dispersal agents. This assumption and temporal overlap in fruiting phenologies were evaluated for the Miconia and Psychotria of central Panama. These two genera accounted for 18 and 27%, respectively, of 1096 fleshy fruits found in regurgitation or faecal samples taken from 2054 birds of 103 species netted in the forest understorey. Two species of manakins accounted for 62% (123/200) of all Miconia fruit taken. Three species of manakins and three species of migratory thrushes accounted for 97% (282/292) of all Psychotria fruits taken. There is a high potential for intrageneric competition for seed dispersal for both plant genera. Null model analyses showed that the fruiting phenologies of Miconia (14 species) are segregated in time, while fruiting of Psychotria (21 species) is highly aggregated. The Miconia were found in up to 24% of the diet samples for the two manakin species, suggesting that Miconia may be a critical resource for both species. The Psychotria fruited when the diversity of understorey fruits was greatest, suggesting a high potential for both intra- and extrageneric competition. The abundance and nomadism of the six bird species that consumed most Psychotria fruit peaked when the Psychotria fruited, supporting the enhancement hypothesis. C1 Smithsonian Trop Res Inst, Ancon, Panama. RP Poulin, B (reprint author), Stn Biol Tour Valat, F-13200 Arles, France. RI Wright, Stuart/M-3311-2013 OI Wright, Stuart/0000-0003-4260-5676 NR 45 TC 66 Z9 73 U1 2 U2 33 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0266-4674 J9 J TROP ECOL JI J. Trop. Ecol. PD MAR PY 1999 VL 15 BP 213 EP 227 DI 10.1017/S0266467499000760 PN 2 PG 15 WC Ecology SC Environmental Sciences & Ecology GA 194CF UT WOS:000080174000006 ER PT J AU Pessier, AP Nichols, DK Longcore, JE Fuller, MS AF Pessier, AP Nichols, DK Longcore, JE Fuller, MS TI Cutaneous chytridiomycosis in poison dart frogs (Dendrobates spp.) and White's tree frogs (Litoria caerulea) SO JOURNAL OF VETERINARY DIAGNOSTIC INVESTIGATION LA English DT Article C1 Smithsonian Inst, Natl Zool Pk, Dept Pathol, Washington, DC 20008 USA. Univ Maine, Dept Biol Sci, Orono, ME 04469 USA. Univ Maine, Darling Marine Ctr, Walpole, ME 04573 USA. RP Pessier, AP (reprint author), Smithsonian Inst, Natl Zool Pk, Dept Pathol, 3001 Connecticut Ave NW, Washington, DC 20008 USA. NR 15 TC 189 Z9 206 U1 6 U2 40 PU AMER ASSOC VETERINARY LABORATORY DIAGNOSTICIANS INC PI TURLOCK PA PO BOX 1522, TURLOCK, CA 95381 USA SN 1040-6387 J9 J VET DIAGN INVEST JI J. Vet. Diagn. Invest. PD MAR PY 1999 VL 11 IS 2 BP 194 EP 199 PG 6 WC Veterinary Sciences SC Veterinary Sciences GA 172MQ UT WOS:000078928700019 PM 10098698 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI The power of display: A history of exhibition installations at the museum of modern art. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Lib, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD MAR 1 PY 1999 VL 124 IS 4 BP 82 EP + PG 2 WC Information Science & Library Science SC Information Science & Library Science GA 172AX UT WOS:000078900100056 ER PT J AU Riley, SM AF Riley, SM TI Indiscretions. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC 20560 USA. RP Riley, SM (reprint author), Smithsonian Inst Lib, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD MAR 1 PY 1999 VL 124 IS 4 BP 108 EP 108 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 172AX UT WOS:000078900100192 ER PT J AU Hamilton, MB AF Hamilton, MB TI Four primer pairs for the amplification of chloroplast intergenic regions with intraspecific variation SO MOLECULAR ECOLOGY LA English DT Article DE chloroplast; Corythophora alta; intergenic region; intraspecific variation; Lecythidaceae; PCR primers ID UNIVERSAL PRIMERS; NONCODING REGIONS; DNA; PLANTS; SET C1 Smithsonian Inst, Natl Zool Pk, Genet Mol Lab, Washington, DC 20008 USA. RP Hamilton, MB (reprint author), Georgetown Univ, Dept Biol, Reiss Bldg, STE 406,Box 571229, Washington, DC 20057 USA. NR 6 TC 465 Z9 488 U1 7 U2 81 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD MAR PY 1999 VL 8 IS 3 BP 521 EP 523 PG 3 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 184WY UT WOS:000079637800022 ER PT J AU Soltis, DE Mort, ME Soltis, PS Hibsch-Jetter, C Zimmer, EA Morgan, D AF Soltis, DE Mort, ME Soltis, PS Hibsch-Jetter, C Zimmer, EA Morgan, D TI Phylogenetic relationships of the enigmatic angiosperm family Podostemaceae inferred from 185 rDNA and rbcL sequence data SO MOLECULAR PHYLOGENETICS AND EVOLUTION LA English DT Article ID COMBINING DATA; FLOWERING PLANTS; DATA SETS; CLASSIFICATION; SAXIFRAGACEAE; POSITION AB The phylogenetic relationships of some angiosperm families have remained enigmatic despite broad phylogenetic analyses of rbcL sequences. One example is the aquatic family Podostemaceae, the relationships of which have long been controversial because of major morphological modifications associated with their aquatic habit. Podostemaceae have variously been associated with Piperaceae, Nepenthaceae, Polygonaceae, Caryophyllaceae, Scrophulariaceae, Rosaceae, Crassulaceae, and Saxifragaceae. Two recent analyses of rbcL sequences suggest a possible sister-group relationship of Podostemaceae to Crassulaceae (Saxifragales). However, the branch leading to Podostemaceae was long, and use of different outgroups resulted in alternative placements. We explored the phylogenetic relationships of Podostemaceae using 18S rDNA sequences and a combined rbcL + 18S rDNA matrix representing over 250 angiosperms. In analyses based on 18S rDNA data, Podostemaceae are not characterized by a long branch; the family consistently appears as part of a Malpighiales clade that also includes Malpighiaceae, Turneraceae, Passifloraceae, Salicaceae, Euphorbiaceae, Violaceae, Linaceae, Chrysobalanaceae, Trigoniaceae, Humiriaceae, and Ochnaceae. Phylogenetic analyses based on a combined 18S rDNA + rbcL data set (223 ingroup taxa) with basal angiosperms as the outgroup also suggest that Podostemaceae are part of a Malpighiales clade. These searches swapped to completion, and the shortest trees showed enhanced resolution and increased internal support compared to those based on 18S rDNA or rbcL alone. However, when Gnetales are used as the outgroup, Podostemaceae appear with members of the nitrogen fixing clade (e.g., Elaeagnaceae, Ulmaceae, Rhamnaceae, Cannabaceae, Moraceae, and Urticaceae). None of the relationships suggested here for Podostemaceae receives strong bootstrap support. Our analyses indicate that Podostemaceae are not closely allied with Crassulaceae or with other members of the Saxifragales clade; their closest relatives, although still uncertain, appear to lie elsewhere in the rosids. (C) 1999 Academic Press. C1 Washington State Univ, Dept Bot, Pullman, WA 99164 USA. Smithsonian Inst, Natl Museum Nat Hist, Lab Mol Systemat, Washington, DC 20560 USA. Western Washington Univ, Dept Biol, Bellingham, WA 98225 USA. RP Soltis, DE (reprint author), Washington State Univ, Dept Bot, Pullman, WA 99164 USA. RI Zimmer, Elizabeth/G-3890-2011; Soltis, Pamela/L-5184-2015 NR 40 TC 35 Z9 40 U1 0 U2 4 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1055-7903 J9 MOL PHYLOGENET EVOL JI Mol. Phylogenet. Evol. PD MAR PY 1999 VL 11 IS 2 BP 261 EP 272 DI 10.1006/mpev.1998.0577 PG 12 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA 186VY UT WOS:000079752400006 PM 10191070 ER PT J AU Volkert, J AF Volkert, J TI Towards a new museum SO MUSEUM NEWS LA English DT Book Review C1 Smithsonian Inst, Natl Museum American Indian, Washington, DC USA. RP Volkert, J (reprint author), Smithsonian Inst, Natl Museum American Indian, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC MUSEUMS PI WASHINGTON PA 1575 EYE ST, NW, STE 400, WASHINGTON, DC 20005 USA SN 0027-4089 J9 MUSEUM NEWS JI Mus. News PD MAR-APR PY 1999 VL 78 IS 2 BP 23 EP + PG 0 WC Art SC Art GA 173VB UT WOS:000078999500005 ER PT J AU Longcore, JE Pessier, AP Nichols, DK AF Longcore, JE Pessier, AP Nichols, DK TI Batrachochytrium dendrobatidis gen et sp nov, a chytrid pathogenic to amphibians SO MYCOLOGIA LA English DT Article DE Chytridiales; chytridiomycosis; Chytridiomycota; frogs; fungus; ultrastructure; zoospore ID LIPID GLOBULE COMPLEX; ZOOSPORE ULTRASTRUCTURE; MORPHOLOGY AB Captive and wild frogs from North and Central America and Australia recently have died with epidermal infections by chytridiomycete fungi. We isolated a chytridiomycete into pure culture from a captive, blue poison dart frog that died at the National Zoological Park in Washington, D.C. Using this isolate, we photographed developmental stages on nutrient agar, examined zoospores with transmission electron microscopy, and inoculated test frogs. This inoperculate chytrid develops either monocentrically or colonially and has thread-like rhizoids that arise from single or multiple areas on die developing zoo-sporangium. The taxonomically important features of the kinetosomal region of the zoospore indicate that this chytrid is a member of the Chytridiales but differs from other chytrids studied with transmission electron microscope Its microtubule root, which begins at kinetosome triplets 9-1 and extends parallel to the kinetosome into the aggregation of ribosomes, is distinctive. Histologic examination of test frogs revealed that the pure culture infected the skin of test frogs, whereas the skin of control frogs remained free of infection. The fungus is described as Batrachochytrium dendrobatidis gen. et sp. nov. C1 Univ Maine, Dept Sci Biol, Orono, ME 04469 USA. Smithsonian Inst, Natl Zool Pk, Dept Pathol, Washington, DC 20008 USA. RP Longcore, JE (reprint author), Univ Maine, Dept Sci Biol, Orono, ME 04469 USA. NR 22 TC 560 Z9 618 U1 26 U2 221 PU NEW YORK BOTANICAL GARDEN PI BRONX PA PUBLICATIONS DEPT, BRONX, NY 10458 USA SN 0027-5514 J9 MYCOLOGIA JI Mycologia PD MAR-APR PY 1999 VL 91 IS 2 BP 219 EP 227 DI 10.2307/3761366 PG 9 WC Mycology SC Mycology GA 179GC UT WOS:000079317100001 ER PT J AU Labandeira, CC Smith, DM AF Labandeira, CC Smith, DM TI Forging a future for fossil insects: thoughts on the First International Congress of Paleoentomology SO PALEOBIOLOGY LA English DT Article C1 Natl Museum Nat Hist, Dept Paleobiol, Smithsonian Inst, Washington, DC 20560 USA. Univ Maryland, Dept Entomol, College Pk, MD 20742 USA. Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA. RP Labandeira, CC (reprint author), Natl Museum Nat Hist, Dept Paleobiol, Smithsonian Inst, Washington, DC 20560 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU PALEONTOLOGICAL SOC INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0094-8373 J9 PALEOBIOLOGY JI Paleobiology PD SPR PY 1999 VL 25 IS 2 BP 154 EP 157 PG 4 WC Biodiversity Conservation; Ecology; Evolutionary Biology; Paleontology SC Biodiversity & Conservation; Environmental Sciences & Ecology; Evolutionary Biology; Paleontology GA 215AD UT WOS:000081359000002 ER PT J AU Faust, MA AF Faust, MA TI Three new Ostreopsis species (Dinophyceae): O-marinus sp nov., O-belizeanus sp nov., and O-carribeanus sp nov. SO PHYCOLOGIA LA English DT Article ID GAMBIERDISCUS-TOXICUS; INCLUDING 2; CORAL-REEFS; DINOFLAGELLATE; SEA AB The morphology of three new species, Ostreopsis marinus sp. nov., Ostreopsis belizeanus sp. nov., and Ostreopsis caribbeanus sp. nov., is described from two geographical regions (Caribbean Sea and southwest Indian Ocean) and four marine habitats (water column, sand, dead corals, and macroalgal surfaces) using scanning electron microscopy. Differences in the following surface morphological characteristics separated these new species from the existing six species of Ostreopsis: cell shape and size and ornamentation of the epitheca, cingulum, and hypotheca. The thecal plate formula of the three new Ostreopsis species is Po, 3', 7", 6C, 6S, Vp, Rp, 5"', Ip, 2"". The most variable characteristics in the genus Ostreopsis are thecal plate size and shape. A morphological comparison of O. marinus sp. nov., O. belizeanus sp. nov., and O. caribbeanus sp. nov. with the six known Ostreopsis species is presented. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Suitland, MD 20746 USA. RP Faust, MA (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Suitland, MD 20746 USA. EM faust.maria@nmnh.si.edu NR 35 TC 36 Z9 39 U1 0 U2 3 PU INT PHYCOLOGICAL SOC PI LAWRENCE PA NEW BUSINESS OFFICE, PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0031-8884 J9 PHYCOLOGIA JI Phycologia PD MAR PY 1999 VL 38 IS 2 BP 92 EP 99 DI 10.2216/i0031-8884-38-2-92.1 PG 8 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 219LZ UT WOS:000081609900003 ER PT J AU Forrey, RC Kharchenko, V Balakrishnan, N Dalgarno, A AF Forrey, RC Kharchenko, V Balakrishnan, N Dalgarno, A TI Vibrational relaxation of trapped molecules SO PHYSICAL REVIEW A LA English DT Article AB Vibrational relaxation of trapped molecules due to collisions with cold atoms is investigated using the results of quantum-mechanical scattering calculations. Trap loss is analyzed using an exactly solvable kinetic model that includes direct collisional quenching and an indirect process of vibrational predissociation. At low atom density, the relaxation is due primarily to collisional quenching. At high atom density, the relaxation involves additional time scales due to the formation and decay of van der Waals complexes. It is shown that the most weakly bound state of the van der Waals complex for a given diatomic vibrational level controls the relaxation at all atom densities. Possible experiments using trapped molecules are: discussed. [S1050-2947(99)05303-2]. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Forrey, RC (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. NR 15 TC 49 Z9 49 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1999 VL 59 IS 3 BP 2146 EP 2152 DI 10.1103/PhysRevA.59.2146 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 177WC UT WOS:000079233200059 ER PT J AU Lukin, MD Matsko, AB Fleischhauer, M Scully, MO AF Lukin, MD Matsko, AB Fleischhauer, M Scully, MO TI Quantum noise and correlations in resonantly enhanced wave mixing based on atomic coherence SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; SQUEEZED STATES; GENERATION; CONVERSION; CAVITY AB We investigate the quantum properties of fields generated by resonantly enhanced wave mixing based on atomic coherence in Raman systems. We show that such a process can be used for generation of pairs of Stokes and anti-Stokes fields with nearly perfect quantum correlations, yielding almost complete (i.e., 100%) squeezing without the use of a cavity. We discuss the extension of the wave mixing interactions into the domain of a few interacting light quanta. [S0031-9007(99)08560-9]. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Max Planck Inst Quantenopt, D-85748 Garching, Germany. Univ Munich, Sekt Phys, D-80333 Munich, Germany. RP Lukin, MD (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RI Matsko, Andrey/A-1272-2007; Fleischhauer, Michael/G-6716-2011 NR 21 TC 153 Z9 156 U1 1 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 1 PY 1999 VL 82 IS 9 BP 1847 EP 1850 DI 10.1103/PhysRevLett.82.1847 PG 4 WC Physics, Multidisciplinary SC Physics GA 171RC UT WOS:000078877000012 ER PT J AU Birkinshaw, M AF Birkinshaw, M TI The Sunyaev-Zel'dovich effect SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE Sunyaev-Zel'dovich effect; clusters; microwave background radiation ID MICROWAVE BACKGROUND-RADIATION; X-RAY BACKGROUNDS; HOT INTERGALACTIC MEDIUM; SMALL-SCALE FLUCTUATIONS; PAIR PC 1643+4631A,B; COLD DARK MATTER; COSMIC MICROWAVE; HUBBLE CONSTANT; COMA CLUSTER; GRAVITATIONAL LENS AB The Sunyaev-Zel'dovich effect causes a change in the apparent brightness of the cosmic microwave background radiation towards a cluster of galaxies or any other reservoir of hot plasma. Measurements of the effect provide distinctly different information about cluster properties than X-ray imaging data, while combining X-ray and Sunyaev-Zel'dovich effect data leads to new insights into the structures of cluster atmospheres. The effect is redshift-independent, and so provides a unique probe of the structure of the Universe on the largest scales. The present review discusses the theory of the Sunyaev-Zel'dovich effect and collects published results for many clusters, presents the overall conclusions that may be drawn from the detections so far, and discusses the prospects for future research on the Sunyaev-Zel'dovich effects. (C) 1999 Elsevier Science B.V. AV rights reserved. C1 Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. Smithsonian Inst Astrophys Observ, Cambridge, MA 02138 USA. RP Birkinshaw, M (reprint author), Univ Bristol, Dept Phys, Tyndall Ave, Bristol BS8 1TL, Avon, England. EM mark.birkinshaw@bristol.ac.uk NR 245 TC 140 Z9 141 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD MAR PY 1999 VL 310 IS 2-3 BP 98 EP 195 PG 98 WC Physics, Multidisciplinary SC Physics GA 170NM UT WOS:000078812300001 ER PT J AU Crew, SR AF Crew, SR TI From Calabar to Carter's Grove: The history of a Virginia slave community SO PUBLIC HISTORIAN LA English DT Book Review C1 Smithsonian Inst, Amer Museum Nat Hist, Washington, DC 20560 USA. RP Crew, SR (reprint author), Smithsonian Inst, Amer Museum Nat Hist, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CALIF PRESS PI BERKELEY PA JOURNALS DEPT 2120 BERKELEY WAY, BERKELEY, CA 94720 USA SN 0272-3433 J9 PUBL HISTORIAN JI Public Hist. PD SPR PY 1999 VL 21 IS 2 BP 144 EP 146 PG 3 WC History SC History GA 207XB UT WOS:000080960100025 ER PT J AU Geller, MJ AF Geller, MJ TI Is cosmology solved? A tribute to David N. Schramm SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Editorial Material C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Geller, MJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD MAR PY 1999 VL 111 IS 757 BP 253 EP 253 DI 10.1086/316323 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 177AM UT WOS:000079185100001 ER PT J AU Gingerich, O AF Gingerich, O TI A brief history of our view of the universe SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article AB Today's cosmological edifice is essentially the product of the 20th century. This account, presented in the Baird Auditorium of the National Museum of Natural History, begins with the Shapley-Curtis debate of 1920, then describes some of its historical background (including why cosmology was almost stillborn with the work of Newton), and finally examines why in 1937 Hubble erred by an order of magnitude in establishing the Hubble constant. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Gingerich, O (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 25 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD MAR PY 1999 VL 111 IS 757 BP 254 EP 257 DI 10.1086/316324 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 177AM UT WOS:000079185100002 ER PT J AU Van Dyk, SD Peng, CY Barth, AJ Filippenko, AV Chevalier, RA Fesen, RA Fransson, C Kirshner, RP Leibundgut, B AF Van Dyk, SD Peng, CY Barth, AJ Filippenko, AV Chevalier, RA Fesen, RA Fransson, C Kirshner, RP Leibundgut, B TI Hubble Space Telescope WFPC2 imaging of SN 1979C and its environment SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID SUPER-NOVA 1979C; STAR-FORMATION REGIONS; LIGHT CURVES; II SUPERNOVAE; RADIO; M100; DISTANCE; EMISSION; SN-1979C; GALAXIES AB The locations of supernovae in the local stellar and gaseous environment in galaxies contain important clues to their progenitor stars. As part of a program to study the environments of supernovae using Hubble Space Telescope imaging data, we have examined the environment of the Type II-L supernova SN 1979C in NGC 4321 (M100). We place rigorous constraints on the mass of the SN progenitor, based on photometry of the stellar populations in its environment. The progenitor may have had an initial mass M approximate to 17-18(+/-3) M.. Moreover, 17 years after explosion we have recovered and measured the brightness of SN 1979C in several bands, e.g., m = 23.37 in F439W [similar to B; for comparison, m(B)(max) = 11.6]. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Dartmouth Coll, Dept Phys & Astron, Hanover, NH 03755 USA. Stockholm Observ, SE-13336 Saltsjobaden, Sweden. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. European So Observ, D-85748 Garching, Germany. RP Van Dyk, SD (reprint author), CALTECH, IPAC, Mail Code 100-22, Pasadena, CA 91125 USA. NR 35 TC 28 Z9 28 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD MAR PY 1999 VL 111 IS 757 BP 313 EP 320 DI 10.1086/316331 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 177AM UT WOS:000079185100009 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI Scribner's American history and culture on CD-ROM, release 1.0. SO REFERENCE & USER SERVICES QUARTERLY LA English DT Software Review C1 Smithsonian Inst Lib, Washington, DC 20560 USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Lib, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER LIBRARY ASSOC PI CHICAGO PA 50 E HURON ST, CHICAGO, IL 60611 USA SN 1094-9054 J9 REF USER SERV Q JI Ref. User Serv. Q. PD SPR PY 1999 VL 38 IS 3 BP 295 EP 296 PG 2 WC Information Science & Library Science SC Information Science & Library Science GA 226TZ UT WOS:000082039300014 ER PT J AU Field, G AF Field, G TI Astrophysics SO REVIEWS OF MODERN PHYSICS LA English DT Article AB During the 100 years that astrophysics has been recognized as a separate discipline, there has been progress in interpreting observations of stars and galaxies using the principles of modern physics. Here we review some of the highlights, including the evolution of stars driven by nuclear reactions in their interiors, the emission of detectable neutrinos by the sun and by a supernova, the rapid and extremely regular rotation of neutron stars, and the accretion of matter onto black holes. A comparison of the observed Universe with the predictions of general relativity is also given. [S0034-6861(99)04602-4]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Field, G (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 32 TC 1 Z9 1 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 J9 REV MOD PHYS JI Rev. Mod. Phys. PD MAR PY 1999 VL 71 IS 2 SI SI BP S33 EP S40 DI 10.1103/RevModPhys.71.S33 PG 8 WC Physics, Multidisciplinary SC Physics GA 172BE UT WOS:000078900800008 ER PT J AU Shapiro, II AF Shapiro, II TI A century of relativity SO REVIEWS OF MODERN PHYSICS LA English DT Article C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Shapiro, II (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 0 TC 20 Z9 21 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 J9 REV MOD PHYS JI Rev. Mod. Phys. PD MAR PY 1999 VL 71 IS 2 SI SI BP S41 EP S53 DI 10.1103/RevModPhys.71.S41 PG 13 WC Physics, Multidisciplinary SC Physics GA 172BE UT WOS:000078900800009 ER PT J AU D'Croz, L Robertson, DR Martinez, JA AF D'Croz, L Robertson, DR Martinez, JA TI Cross-shelf distribution of nutrients, plankton, and fish larvae in the San Bias Archipelago, Caribbean Panama SO REVISTA DE BIOLOGIA TROPICAL LA English DT Article DE nutrients; plankton; fish larvae; cross-shelf distribution; Caribbean Panama ID GREAT-BARRIER-REEF; CORAL-REEFS; EUTROPHICATION; AUSTRALIA AB To investigate possible seasonal patterns in water quality and plankton distribution, weekly samples were collected in a coral reef lagoon and in surrounding nearshore waters over a two year period. Additionally, two oceanographic surveys were also conducted in a larger area surrounding the primary study site during the seasonal extremes. The resulting information corroborated previous observations that this area is as an oligotrophic environment. The larger-scale sampling revealed seasonal variation in cross-shelf gradients in plankton, fish-egg and larval densities that are probably related to the strong onshore winds that are typically present during the dry season. Although some limited nutrient enrichment occurs in parts of the nearshore area during the rainy season, the highest plankton density and biomass were recorded in shallow nearshore waters during the windy dry season. Larvae of numerous fish taxa were collected in these nearshore areas during the dry season, suggesting seasonal aggregation. During the rainy season, fish larvae were spread more evenly across the shelf and into nearshelf waters. C1 Smithsonian Trop Res Inst, Balboa, Panama. RP D'Croz, L (reprint author), Smithsonian Trop Res Inst, Box 2072, Balboa, Panama. NR 23 TC 11 Z9 12 U1 1 U2 4 PU REVISTA DE BIOLOGIA TROPICAL PI SAN JOSE PA UNIVERSIDAD DE COSTA RICA CIUDAD UNIVERSITARIA, SAN JOSE, COSTA RICA SN 0034-7744 J9 REV BIOL TROP JI Rev. Biol. Trop. PD MAR-JUN PY 1999 VL 47 IS 1-2 BP 203 EP 215 PG 13 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 258PD UT WOS:000083846800019 ER PT J AU Adams, RM AF Adams, RM TI Part II: Case histories: Ways in which foods have emerged, migrated, and been assimilated - Introduction SO SOCIAL RESEARCH LA English DT Editorial Material C1 Smithsonian Inst, Washington, DC 20560 USA. RP Adams, RM (reprint author), Univ Calif San Diego, La Jolla, CA 92093 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NEW SCHOOL UNIV PI NEW YORK PA GRADUATE FACULTY, 65 5TH AVE, RM 354, NEW YORK, NY 10003 USA SN 0037-783X J9 SOC RES JI Soc. Res. PD SPR PY 1999 VL 66 IS 1 BP 39 EP 40 PG 2 WC Social Sciences, Interdisciplinary SC Social Sciences - Other Topics GA 326EP UT WOS:000087720000005 ER PT J AU Alroy, J AF Alroy, J TI The fossil record of North American mammals: Evidence for a Paleocene evolutionary radiation SO SYSTEMATIC BIOLOGY LA English DT Article DE body mass; Cenozoic; Cretaceous; diversification; extinction; Mammalia; molecular clock ID DIVERSIFICATION; DISPARITY; RODENT; BIRDS AB Paleontologists long have argued that the most important evolutionary radiation of mammals occurred during the early Cenozoic, if not that all eutherians originated from a single common post-Cretaceous ancestor. Nonetheless, several recent molecular analyses claim to show that because several interordinal splits occurred during the Cretaceous, a major therian radiation was then underway This claim conflicts with statistical evidence from the well-sampled latest Cretaceous and Cenozoic North American fossil record. Paleofaunal data confirm that there were fewer mammalian species during the latest Cretaceous than during any interval of the Cenozoic, and that a massive diversification took place during the early Paleocene, immediately after a mass extinction. Measurement data show that Cretaceous mammals were on average small and occupied a narrow range of body sizes; after the Cretaceous-Tertiary mass extinction, there was a rapid and permanent shift in the mean. The fact that there was an early Cenozoic mammalian radiation is entirely compatible with the existence of a few Cretaceous splits among modern mammal lineages. C1 Smithsonian Inst, Dept Paleobiol, MRC 121, Washington, DC 20560 USA. RP Alroy, J (reprint author), Univ Calif Santa Barbara, Natl Ctr Ecol Anal & Synth, 735 State St,Suite 300, Santa Barbara, CA 93101 USA. RI Alroy, John/B-4585-2009 NR 40 TC 132 Z9 139 U1 11 U2 41 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 1063-5157 J9 SYST BIOL JI Syst. Biol. PD MAR PY 1999 VL 48 IS 1 BP 107 EP 118 DI 10.1080/106351599260472 PG 12 WC Evolutionary Biology SC Evolutionary Biology GA 187VN UT WOS:000079808900009 PM 12078635 ER PT J AU Piperno, DR Pearsall, DM Benfer, RA Kealhofer, L Zhao, ZJ Jiang, QH AF Piperno, DR Pearsall, DM Benfer, RA Kealhofer, L Zhao, ZJ Jiang, QH TI Phytolith morphology SO SCIENCE LA English DT Letter C1 Smithsonian Trop Res Inst, Ctr Trop Paleoecol & Archaeol, Balboa, Panama. Univ Missouri, Dept Anthropol, Amer Archaeol Div, Columbia, MO 65211 USA. Coll William & Mary, Dept Anthropol, Williamsburg, VA 23187 USA. Chinese Acad Social Sci, Archaeol Inst, Beijing, Peoples R China. Peking Univ, Dept Geol, Beijing 100871, Peoples R China. RP Piperno, DR (reprint author), Smithsonian Trop Res Inst, Ctr Trop Paleoecol & Archaeol, Balboa, Panama. NR 21 TC 6 Z9 6 U1 0 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD FEB 26 PY 1999 VL 283 IS 5406 BP 1265 EP 1266 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 171AM UT WOS:000078839900017 ER PT J AU Clayton, DD Liu, WH Dalgarno, A AF Clayton, DD Liu, WH Dalgarno, A TI Condensation of carbon in radioactive supernova gas SO SCIENCE LA English DT Article ID RADIATIVE ASSOCIATION; INTERSTELLAR CLOUDS; MURCHISON METEORITE; LARGE HYDROCARBONS; PRESOLAR GRAPHITE; CLUSTERS; MATTER; ORIGIN; GRAINS AB Chemistry resulting in the formation of Large carbon-bearing molecules and dust in the interior of an expanding supernova was explored, and the equations governing their abundances were solved numerically, Carbon dust condenses from initially gaseous carbon and oxygen atoms because energetic electrons produced by radioactivity in the supernova cause dissociation of the carbon monoxide molecules, which would otherwise form and Limit the supply of carbon atoms, The resulting free carbon atoms enable carbon dust to grow faster by carbon association than the rate at which the dust can be destroyed by oxidation. The origin of presolar micrometer-sized carbon solids that are found in meteorites is thereby altered. C1 Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Clayton, DD (reprint author), Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. NR 34 TC 91 Z9 91 U1 1 U2 10 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD FEB 26 PY 1999 VL 283 IS 5406 BP 1290 EP 1292 DI 10.1126/science.283.5406.1290 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 171AM UT WOS:000078839900030 PM 10037591 ER PT J AU Bukowski, R Sadlej, J Jeziorski, B Jankowski, P Szalewicz, K Kucharski, SA Williams, HL Rice, BM AF Bukowski, R Sadlej, J Jeziorski, B Jankowski, P Szalewicz, K Kucharski, SA Williams, HL Rice, BM TI Intermolecular potential of carbon dioxide dimer from symmetry-adapted perturbation theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INFRARED-ABSORPTION SPECTROSCOPY; MOLECULAR-ORBITAL CALCULATIONS; DER-WAALS COMPLEXES; AB-INITIO; INTERACTION ENERGY; SOLID CO2; ELECTROSTATIC INTERACTIONS; VANDERWAALS COMPLEXES; PAIR POTENTIALS; CLUSTER IONS AB A four-dimensional intermolecular potential energy surface for the carbon dioxide dimer has been computed using the many-body symmetry-adapted perturbation theory (SAPT) and a large 5s3p2d1f basis set including bond functions. The SAPT level applied is approximately equivalent to the supermolecular many-body perturbation theory at the second-order level. An accurate fit to the computed data has been obtained in a form of an angular expansion incorporating the asymptotic coefficients computed ab initio at the level consistent with the applied SAPT theory. A simpler site-site fit has also been developed to facilitate the use of the potential in molecular dynamics and Monte Carlo simulations. The quality of the new potential has been tested by computing the values of the second virial coefficient which agree very well with the experimental data over a wide range of temperatures. Our potential energy surface turns out to be substantially deeper than previous ab initio potentials. The minimum of -484 cm(-1) has been found for the slipped parallel geometry at the intermolecular separation R = 3.54 Angstrom and a saddle point at -412 cm(-1) for the T-shaped configuration and R = 4.14 Angstrom. Three minima and two first-order saddle points have been located on the pairwise-additive potential energy surface of the CO(2) trimer. The nonplanar structure of C(2) symmetry has been found to be 48.8 cm(-1) more stable than the cyclic planar form of C(3h) symmetry, in disagreement with experimental observation. It is suggested that the relative stability of the two isomers cannot be reliably determined by pairwise-additive potential and inclusion of three-body forces is necessary for this purpose. (C) 1999 American Institute of Physics. [S0021-9606(99)30208-7]. C1 Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. USA, Res Lab, Aberdeen Proving Ground, MD 21005 USA. Warsaw Univ, Dept Chem, PL-02093 Warsaw, Poland. Pedag Univ, Inst Phys, PL-42200 Czestochowa, Poland. Silesian Univ, Dept Chem, PL-40006 Katowice, Poland. RP Bukowski, R (reprint author), Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA. RI Jankowski, Piotr/O-5874-2015 NR 92 TC 231 Z9 233 U1 2 U2 41 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 22 PY 1999 VL 110 IS 8 BP 3785 EP 3803 DI 10.1063/1.479108 PG 19 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 168AX UT WOS:000078668900022 ER PT J AU Yuan, JM Liu, WK Hayashi, MT Lin, SH AF Yuan, JM Liu, WK Hayashi, MT Lin, SH TI Quantum dynamics of chirped excitation of multimode systems SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INFRARED-LASER PULSES; VIBRATIONAL-EXCITATION; DISSOCIATION; MOLECULES; STATES; PHOTODESORPTION; DECOHERENCE; OSCILLATOR; SURFACES; SPACE AB We investigate the effectiveness of chirped laser pulses in exciting a multimode system, where a vibrational mode is coupled to a large number of bath modes. We solve the Liouville equation for this model numerically to investigate the roles played by laser frequency, laser intensity, pulse width, frequency sweeping rate, and bath relaxation times in inducing vibrational excitation. We investigate the range of parameters for which chirping excitation is efficient for multimode systems. In addition, we study constant-frequency excitations using the present model, revealing the special effects of phase relaxation time and the phenomenon of molecular bistability. Furthermore, we present results on quantum decoherence and assess the validity of an effective Hamiltonian method. (C) 1999 American Institute of Physics. [S0021-9606(99)00806-5]. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Waterloo, Dept Phys, Waterloo, ON N2L 3G1, Canada. Acad Sinica, Inst Atom & Mol Sci, Taipei, Taiwan. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. RP Yuan, JM (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. RI Hayashi, Michitoshi/K-6314-2014 OI Hayashi, Michitoshi/0000-0001-7507-8708 NR 40 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 22 PY 1999 VL 110 IS 8 BP 3823 EP 3834 DI 10.1063/1.478271 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 168AX UT WOS:000078668900025 ER PT J AU Peters, JM Queller, DC Imperatriz-Fonseca, VL Roubik, DW Strassmann, JE AF Peters, JM Queller, DC Imperatriz-Fonseca, VL Roubik, DW Strassmann, JE TI Mate number, kin selection and social conflicts in stingless bees and honeybees SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE kin selection; mate number; social conflict; microsatellite; Apis; Meliponini ID EUSOCIAL HYMENOPTERA; APIDAE; COLONIES; WORKERS; MELIPONINAE; RELATEDNESS; POLYANDRY; QUEENS; APIS AB Microsatellite genotyping of workers from 13 species (ten genera) of stingless bees shows that genetic relatedness is very high. Workers are usually daughters of a single, singly mated queen. This observation, coupled with the multiple mating of honeybee queens, permits kin selection theory to account for many differences in the social biology of the two taxa. First, in contrast to honeybees, where workers are predicted to and do police each other's male production, stingless bee workers are predicted to compete directly with the queen for rights to produce males. This leads to behavioural and reproductive conflict during oviposition. Second, the risk that a daughter queen will attack the mother queen is higher in honeybees, as is the cost of such an attack to workers. This explains why stingless bees commonly have virgin queens in the nest, but honeybees do not. It also explains why in honeybees the mother queen leaves to found a new nest, while in stingless bees it is the daughter queen who leaves. C1 Rice Univ, Dept Ecol & Evolutionary Biol, Houston, TX 77251 USA. Univ Sao Paulo, Inst Biociencias, Dept Ecol Geral, BR-05508900 Sao Paulo, Brazil. Smithsonian Trop Res Inst, Balboa, Panama. RP Queller, DC (reprint author), Rice Univ, Dept Ecol & Evolutionary Biol, POB 1892, Houston, TX 77251 USA. EM queller@rice.edu RI Imperatriz-Fonseca, Vera/H-5582-2012; OI Imperatriz-Fonseca, Vera/0000-0002-1079-2158; Strassmann, Joan/0000-0003-0638-8440 NR 40 TC 113 Z9 118 U1 2 U2 33 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD FEB 22 PY 1999 VL 266 IS 1417 BP 379 EP 384 PG 6 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA 171LD UT WOS:000078864400009 ER PT J AU Smith, CH Bourke, TL Wright, CM Spoon, HWW Aitken, DK Robinson, G Storey, JWV Fujiyoshi, T Roche, PF Lehmann, T AF Smith, CH Bourke, TL Wright, CM Spoon, HWW Aitken, DK Robinson, G Storey, JWV Fujiyoshi, T Roche, PF Lehmann, T TI Mid-infrared imaging and spectroscopy of the southern H II region RCW 38 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : formation; H II regions; ISM : individual : RCW 38; infrared : ISM : continuum ID EARLY-TYPE STARS; OPTICAL-PROPERTIES; INTERSTELLAR DUST; GALACTIC SOURCES; GAMMA-RATIO; H-2 REGIONS; MODEL; EMISSION; SPECTRA; LINES AB We present mid-infrared images and an 8-13 mu m spectrum of the southern HIT region RCW 38. We determine the dust colour temperature from both our spectrum and images at 10 and 20 mu m, and deduce the gas excitation from an image in the [S IV] fine-structure line, as well as spectra of the [Ar III], [S IV] and [Ne II] fine-structure lines. Our observations are consistent with a complex of sources associated with the RCW 38 IRS1 region, which represent knots of material in a shell, or ridge, surrounding a cavity of about 0.1 pc in radius, which is itself created by the stellar wind of the hot young source IRS2, The dust temperature does not peak closest to IRS2, but rather along the centre of the ridge, and is remarkably uniform over the extent of our image. From photoionization models for the observed line ratios at IRS I we deduce a stellar effective temperature and gas density of about 43 000-48 000 K and 10(4) cm(-3) respectively. Whilst the star, or star cluster, IRS2 is ultimately responsible for the observed thermal and ionic emission, the relatively uniform dust temperature implies that the bulk of the dust heating in the region is provided by resonantly trapped Lyman alpha photons, rather than direct stellar photons. This then also implies that the dust is depleted with respect to the gas by a factor of at least 100 from its normal interstellar value. The small-scale spatial variations in the continuum emission and temperature can be explained by changes in the density and/or gas-to-dust mass ratio. C1 UNSW, ADFA, Univ Coll, Sch Phys, Canberra, ACT 2600, Australia. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Univ Hertfordshire, Div Phys Sci, Hatfield AL10 9AB, Herts, England. Univ New S Wales, Sch Phys, Sydney, NSW 2052, Australia. Univ Oxford, Dept Astrophys, Oxford OX1 3RH, England. Inst Astrophys, D-07745 Jena, Germany. Univ Observ, D-07745 Jena, Germany. RP Smith, CH (reprint author), UNSW, ADFA, Univ Coll, Sch Phys, Canberra, ACT 2600, Australia. OI Roche, Patrick/0000-0002-8524-8413 NR 74 TC 16 Z9 16 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD FEB 21 PY 1999 VL 303 IS 2 BP 367 EP 379 DI 10.1046/j.1365-8711.1999.02241.x PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 175QY UT WOS:000079107500021 ER PT J AU Di Stefano, R AF Di Stefano, R TI Microlensing and the search for extraterrestrial life SO ASTROPHYSICAL JOURNAL LA English DT Article DE extraterrestrial intelligence; gravitational lensing; planetary systems ID PLANETARY SYSTEMS; EVENTS; HABITABILITY; COMPANION; EUROPA; LIGHT AB Are microlensing searches likely to discover planets that harbor life? Given our present state of knowledge, this is a difficult question to answer. We therefore begin by asking a more narrowly focused question: are conditions on planets discovered via microlensing likely to be similar to those we experience on Earth? In this paper I link the microlensing observations to the well-known "Goldilocks problem" (conditions on the Earth-like planets need to be "just right") to find that Earth-like planets discovered via microlensing are likely to be orbiting stars more luminous than the Sun. This means that light from the planetary system's central star may contribute a significant fraction of the baseline flux relative to the star that is lensed. Such blending of light from the lens with light from the lensed source can, in principle, limit our ability to detect these events. This turns out not to be a significant problem, however. A second consequence of blending is the opportunity to determine the spectral type of the lensed star. This circumstance? plus the possibility that finite-source-size effects are important, implies that some meaningful follow-up observations are likely to be possible for a subset of Earth-like planets discovered via microlensing. In addition, calculations indicate that reasonable requirements on the planet's density and surface gravity imply that the mass of Earth-like planets is likely to be within a factor of similar to 15 of an Earth mass. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Di Stefano, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 32 TC 10 Z9 10 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1999 VL 512 IS 2 BP 558 EP 563 DI 10.1086/306813 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187VP UT WOS:000079809000006 ER PT J AU Di Stefano, R Scalzo, RA AF Di Stefano, R Scalzo, RA TI A new channel for the detection of planetary systems through microlensing. I. Isolated events due to planet lenses SO ASTROPHYSICAL JOURNAL LA English DT Article DE extraterrestrial intelligence; Galaxy, halo; gravitational lensing; planetary systems ID GALACTIC DARK HALO; MACHO PROJECT; GRAVITATIONAL MICROLENSES; EXTRASOLAR PLANETS; LIGHT CURVES; STARS; MASS; CANDIDATE; STELLAR; LIMITS AB We propose and evaluate the feasibility of a new strategy to search for planets via microlensing observations. This new strategy is designed to detect planets in "wide" orbits, i.e., with orbital separation, a, greater than similar to 1.5R(E). Planets in wide orbits may provide the dominant channel for the discovery of planets via microlensing, particularly low-mass (e.g., Earth-mass) planets. This paper concentrates on events in which a single planet serves as a lens, leading to an isolated event of short duration. We point out that a distribution of events due to lensing by stars with wide-orbit planets is necessarily accompanied by a distribution of shorter duration events. The fraction of events in the latter distribution is proportional to the average value of q(1/2), where q is the ratio between planet and stellar masses. The position of the peak or peaks also provides a measure of the mass ratios typical of planetary systems. We study detection strategies that can optimize our ability to discover isolated short-duration events due to lensing by planets and find that monitoring employing sensitive photometry is particularly useful. If planetary systems similar to our own are common, even modest changes in detection strategy should lead to the discovery a few isolated events of short duration every year. We therefore also address the issue of the contamination due to stellar populations of any microlensing signal due to low-mass MACHOs. We describe how, even for isolated events of short duration, it will be possible to test the hypothesis that the lens was a planet instead of a low-mass MACHO, if the central star of the planetary system contributes a measurable fraction of the baseline Bur. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. RP Di Stefano, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM rdistefano@cfa.harvard.edu; rscalzo@rainbow.uchicago.edu NR 50 TC 32 Z9 32 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1999 VL 512 IS 2 BP 564 EP 578 DI 10.1086/306814 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187VP UT WOS:000079809000007 ER PT J AU Di Stefano, R Scalzo, RA AF Di Stefano, R Scalzo, RA TI A new channel for the detection of planetary systems through microlensing. II. Repeating events SO ASTROPHYSICAL JOURNAL LA English DT Article DE gravitational lensing; planetary systems ID GRAVITATIONAL LENSING EXPERIMENT; GALACTIC BULGE; MACHO PROJECT; STARS; CANDIDATE; SEARCH; LIGHT; HALO; M31 AB In the companion paper we began the task of systematically studying the detection of planets in wide orbits (a > 1.5R(E)) via microlensing surveys. In this paper we continue, focusing on repeating events. Repeating events are those in which a distant source is lensed by two or more masses in the planetary system. We find that, if all planetary systems are similar to our own solar system, reasonable extensions of the present observing strategies would allow us to detect 3-6 repeating events per year along the direction to the Bulge. Indeed, if planetary systems with multiple planets are common, then future monitoring programs that lead to the discovery of thousands of stellar-lens events will likely discover events in which several different planets within a single system serve as lenses, with light curves exhibiting multiple repetitions. In this paper we discuss observing strategies to maximize the discovery of all wide-orbit planet-lens events. We also compare the likely detection rates of planets in wide orbits to those of planets located in the zone for resonant lensing. We find that, depending on the values of the planet masses and stellar radii of the lensed sources (which determine whether or not finite-source-size effects are important), and also on the sensitivity of the photometry used by observers, the detection of planets in wide orbits may be the primary route to the discovery of planets via microlensing. We also discuss how the combination of resonant and wide-orbit events can help us to learn about the distribution of planetary system properties. In addition, by determining the fraction of short-duration events due to planets, we indirectly derive information about the fraction of all short-duration events that may be due to low-mass MACHOs. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. RP Di Stefano, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 40 TC 40 Z9 40 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1999 VL 512 IS 2 BP 579 EP 600 DI 10.1086/306782 PN 1 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187VP UT WOS:000079809000008 ER PT J AU Bergin, EA Plume, R Williams, JP Myers, PC AF Bergin, EA Plume, R Williams, JP Myers, PC TI The ionization fraction in dense molecular gas. II. Massive cores SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM, abundances; ISM, clouds; ISM, molecules ID YOUNG STELLAR OBJECTS; CLOUD CORES; STAR-FORMATION; SUBMILLIMETER CONTINUUM; PROTOSTELLAR CORES; THERMAL BALANCE; WATER MASERS; DARK CLOUDS; EMISSION; ORION AB We present an observational and theoretical study of the ionization fraction in several massive cores located in regions that are currently forming stellar clusters. Maps of the emission from the J = 1-->0 transitions of (CO)-O-18, DCO+, N2H+, and (HCO+)-C-13, as well as the J = 2-->1 and 3-->2 transitions of CS, were obtained for each core. Core densities are determined via a large velocity gradient analysis with values typically of similar to 10(5) cm(-3). With the use of observations to constrain variables in the chemical calculations, we derive electron fractions for our overall sample of five cores directly associated with star formation and two apparently starless cores. The electron abundances are found to lie within a small range, -6.9 < log(10) x(e) < -7.3, and are consistent with previous work. We find no difference in the amount of ionization fraction between cores with and without associated star formation activity, nor is any difference found in electron abundances between the edge and center of the emission region. Thus our models are in agreement with the standard picture of cosmic rays as the primary source of ionization for molecular ions. With the addition of previously determined electron abundances for low-mass cores, and even more massive cores associated with O and B clusters, we systematically examine the ionization fraction as a function of star formation activity. This analysis demonstrates that the most massive sources stand out as having the lowest electron abundances (x(e) < 10(-8)). C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Bergin, EA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Williams, Jonathan/B-1643-2009; OI Williams, Jonathan/0000-0001-5058-695X NR 55 TC 47 Z9 47 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1999 VL 512 IS 2 BP 724 EP 739 DI 10.1086/306791 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187VP UT WOS:000079809000019 ER PT J AU Henry, TJ Franz, OG Wasserman, LH Benedict, GF Shelus, PJ Ianna, PA Kirkpatrick, JD McCarthy, DW AF Henry, TJ Franz, OG Wasserman, LH Benedict, GF Shelus, PJ Ianna, PA Kirkpatrick, JD McCarthy, DW TI The optical mass-luminosity relation at the end of the main sequence (0.08-0.20 M-circle dot) SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrometry; binaries : close; stars : low-mass, brown dwarfs; stars : luminosity function, mass function; stars : statistics; techniques : interferometric ID SOLAR NEIGHBORHOOD; STELLAR MASSES; STARS; EVOLUTION; DWARFS; RADII AB The empirical mass-luminosity relation at M-V is presented for stars with masses 0.08-0.20 M-. based upon new observations made with Fine Guidance Sensor 3 on the Hubble Space Telescope. The targets are nearby, red dwarf multiple systems in which the magnitude differences are typically measured to +/-0.1 mag or better. The M-V values are generated using the best available parallaxes and are also accurate to +/-0.1 mag, because the errors in the magnitude differences are the dominant error source. In several cases this is the first time the observed sub-arcsecond multiples have been resolved at optical wavelengths. The mass-luminosity relation defined by these data reaches to M-V = 18.5 and provides a powerful empirical test for discriminating the lowest mass stars from high-mass brown dwarfs at wavelengths shorter than 1 mu m. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Lowell Observ, Flagstaff, AZ 86001 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. CALTECH, IPAC, Pasadena, CA 91125 USA. Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. RP Henry, TJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 31 TC 130 Z9 132 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1999 VL 512 IS 2 BP 864 EP 873 DI 10.1086/306793 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187VP UT WOS:000079809000029 ER PT J AU Hartigan, P Morse, JA Tumlinson, J Raymond, J Heathcote, S AF Hartigan, P Morse, JA Tumlinson, J Raymond, J Heathcote, S TI Hubble Space Telescope faint object spectrograph optical and ultraviolet spectroscopy of the bow shock HH 47A SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; ISM : jets and outflows; shock waves; stars : individual (HH 47A); stars : pre-main-sequence ID HERBIG-HARO OBJECTS; NOVA RR-TEL; FE-II; STELLAR JETS; OSCILLATOR-STRENGTHS; H-2 EMISSION; YOUNG STARS; ATOMIC DATA; SUPER-NOVA; HH-47 JET AB We present new spectra obtained with the Faint Object Spectrograph aboard the Hubble Space Telescope of the HH 47A bow shock and Mach disk that cover the entire spectral range between lambda lambda 2220 and 6810. In addition to emission lines seen previously from HH objects, we uncover over a dozen weak Fe II transitions in the ultraviolet. The flux ratios between these permitted lines can only be understood if transitions to the ground state are resonantly scattered within HH 47A. The expected column density of Fe rr within HH 47A suffices to scatter these lines, although the scattering optical depths imply that the Fe II line broadening must exceed that expected from thermal motions. Excitation of ultraviolet Fe II occurs locally within HH 47A, probably from collisions within the hot postshock gas and not from UV pumping from some nearby O stars. The data show no evidence for significant depletion of Fe within HH 47A. The emission line's fluxes and ratios indicate that jet material currently enters the Mach disk with a density of similar to 350 cm(-3) and a velocity of similar to 40 km s(-1). The mass-loss rate of the exciting star, as measured by the mass flux through the Mach disk, is 1.6 x 10(-8) M. yr(-1). This mass-loss rate is considerably lower than that closer to the star where the jet is brighter, probably because the density along the jet is highly nonuniform. A single-shock velocity does not match the bow shock spectrum well. We propose that secondary shocks reheat the gas within the cooling zone of the HH 47A bow shock. Compression from the first shock will cause these secondary shocks to be strongly magnetized, and the secondary shocks should emit strongly in low-excitation lines such as Mg II, C II], and [S II]. The weak blue continua seen at optical wavelengths in spectra of the Mach disk and bow shock extend into the ultraviolet and have spectral energy distributions and total fluxes consistent with those expected from two-photon emission. C1 Rice Univ, Dept Space Phys & Astron, Houston, TX 77005 USA. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Opt Astron Observ, Cerro Tololo Inter Amer Observ, La Serena, Chile. RP Rice Univ, Dept Space Phys & Astron, POB 1892,6100 S Main, Houston, TX 77005 USA. NR 57 TC 32 Z9 32 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1999 VL 512 IS 2 BP 901 EP 915 DI 10.1086/306792 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187VP UT WOS:000079809000032 ER PT J AU Kaghashvili, EK AF Kaghashvili, EK TI On the acceleration of the solar wind: Role of the inhomogeneous flow SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; solar wind; waves ID ALFVEN WAVES; ACCRETION DISKS; SHEAR FLOWS; ENERGY-FLOW; INSTABILITY; CHROMOSPHERE; ATMOSPHERE; FLUX AB It is shown that an inhomogeneous flow is capable of converting Alfven waves escaping from the solar atmosphere into other types of MHD waves that can be efficiently dissipated. The efficiency of this process depends on local characteristics of the medium. Using the geometry of the solar wind, it is shown how this mechanism operates in different regions of the solar wind and what the preferred way of the coupling process is in those regions. It is suggested that mode conversion induced by inhomogeneous flow, particularly by shear velocity flow, could be the basic mechanism required for the solar wind acceleration in the coronal holes. It is shown that this mechanism is most efficient in the fast-expanding regions of polar coronal holes and how it contributes to the detected long-period Alfven waves and density fluctuations in the solar wind. The results demonstrated by numerical simulations coincide with observations. C1 Abastumani Astrophys Observ Kazbegi, GE-380060 Tbilisi, Rep of Georgia. RP Kaghashvili, EK (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 42 TC 26 Z9 26 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1999 VL 512 IS 2 BP 969 EP 974 DI 10.1086/306817 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187VP UT WOS:000079809000038 ER PT J AU Arce, HG Goodman, AA AF Arce, HG Goodman, AA TI Measuring galactic extinction: A test SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; infrared : ISM : continuum ID INFRARED-EMISSION; GALAXY COUNTS; MOLECULAR GAS; CLOUD; RATIO; MAPS; H-1 AB We test the recently published all-sky reddening map of Schlegel, Finkbeiner, & Davis (hereafter SFD) using the extinction study of a region in the Taurus dark cloud complex by Arce & Goodman (hereafter AG). In their study, AG use four different techniques to measure the amount and structure of the extinction toward Taurus, and all four techniques agree very well. Thus, we believe that the AG results are a truthful representation of the extinction in the region and can be used to test the reliability of the SFD reddening map. The results of our test show that the SFD all-sky reddening map, which is based on data from COBE/DIRBE and IRAS/ISSA, overestimates the reddening by a factor of 1.3-1.5 in regions of smooth extinction with A(v) > 0.5 mag. In some regions of steep extinction gradients, the SFD map underestimates the reddening value, probably because of its low spatial resolution. We expect that the astronomical community will be using the SFD reddening map extensively. We offer this Letter as a cautionary note about using the SFD map in regions of high extinction (A, > 0.5 mag), since it might not be giving accurate reddening values there. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Arce, HG (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Goodman, Alyssa/A-6007-2010 OI Goodman, Alyssa/0000-0003-1312-0477 NR 10 TC 77 Z9 78 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1999 VL 512 IS 2 BP L135 EP L138 DI 10.1086/311885 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187VR UT WOS:000079809200014 ER PT J AU Richman, LK Montali, RJ Garber, RL Kennedy, MA Lehnhardt, J Hildebrandt, T Schmitt, D Hardy, D Alcendor, DJ Hayward, GS AF Richman, LK Montali, RJ Garber, RL Kennedy, MA Lehnhardt, J Hildebrandt, T Schmitt, D Hardy, D Alcendor, DJ Hayward, GS TI Novel endotheliotropic herpesviruses fatal for Asian and African elephants SO SCIENCE LA English DT Article ID INFECTION; MAXIMUS AB A highly fatal hemorrhagic disease has been identified in 10 young Asian and African elephants at North American toes. In the affected animals there was ultrastructural evidence for herpesvirus-like particles in endothelial cells of the heart, liver, and tongue. Consensus primer polymerase chain reaction combined with sequencing yielded molecular evidence that confirmed the presence of two novel but rotated herpesviruses associated with the disease, one in Asian elephants and another in African elephants. Otherwise healthy African elephants with external herpetic Lesions yielded herpesvirus sequences identical to that found in Asian elephants with endothelial disease. This finding suggests that the Asian elephant deaths were caused by cross-species infection with a herpesvirus that is naturally latent in, but normally not lethal to, African elephants, A reciprocal relationship may exist for the African elephant disease. C1 Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. Johns Hopkins Sch Med, Baltimore, MD 21205 USA. PathoGenesis Corp, Seattle, WA 98119 USA. Univ Tennessee, Knoxville, TN 37901 USA. Inst Zoo Biol & Wildlife Res, D-10305 Berlin, Germany. SW Missouri State Univ, Springfield, MO 65804 USA. Dickerson Pk Zoo, Springfield, MO 65803 USA. RP Richman, LK (reprint author), Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. FU NIAID NIH HHS [1 K08 AI01526-01] NR 10 TC 93 Z9 95 U1 3 U2 19 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD FEB 19 PY 1999 VL 283 IS 5405 BP 1171 EP 1176 DI 10.1126/science.283.5405.1171 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 169GD UT WOS:000078738400053 PM 10024244 ER PT J AU Iizasa, K Fiske, RS Ishizuka, O Yuasa, M Hashimoto, J Ishibashi, J Naka, J Horii, Y Fujiwara, Y Imai, A Koyama, S AF Iizasa, K Fiske, RS Ishizuka, O Yuasa, M Hashimoto, J Ishibashi, J Naka, J Horii, Y Fujiwara, Y Imai, A Koyama, S TI A Kuroko-type polymetallic sulfide deposit in a submarine silicic caldera SO SCIENCE LA English DT Article ID EAST PACIFIC RISE; IZU-OGASAWARA ARC; NORTHWESTERN PACIFIC; FLOOR SEDIMENTS; RIDGE; BASIN; GOLD AB Manned submersible studies have delineated a large and actively growing Kuroko-type volcanogenic massive sulfide deposit 400 kilometers south of Tokyo in Myojin Knell submarine caldera, The sulfide body is Located on the caldera floor at a depth of 1210 to 1360 meters, has an area of 400 by 400 by 30 meters, and is notably rich in gold and silver. The discovery of a Large Kuroko-type polymetallic sulfide deposit in this are-front caldera raises the possibility that the numerous unexplored submarine silicic calderas elsewhere might have similar deposits. C1 Smithsonian Inst, Washington, DC 20560 USA. Geol Survey Japan, Ibaraki, Osaka 3058567, Japan. Japan Marine Sci & Technol Ctr 2 15, Yokosuka, Kanagawa 2370061, Japan. Univ Tokyo, Tokyo 1330033, Japan. Tokyo Metropolitan Fisheries Stn, Tokyo 1001511, Japan. RP Fiske, RS (reprint author), Smithsonian Inst, MRC-119, Washington, DC 20560 USA. EM rfiske@volcano.si.edu NR 23 TC 118 Z9 124 U1 0 U2 10 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD FEB 12 PY 1999 VL 283 IS 5404 BP 975 EP 977 DI 10.1126/science.283.5404.975 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 166KM UT WOS:000078574800045 ER PT J AU Siemiginowska, A Elvis, M AF Siemiginowska, A Elvis, M TI Active galactic nuclei - Unstable by design SO NATURE LA English DT Editorial Material ID ACCRETION-DISK C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Siemiginowska, A (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD FEB 11 PY 1999 VL 397 IS 6719 BP 476 EP + DI 10.1038/17223 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 166KN UT WOS:000078574900027 ER PT J AU Cirignano, L Shah, KS Bennett, PR Klugerman, M Dmitryev, Y Squillante, MR Narita, T Bloser, P Grindlay, J Hasegawa, BH Iwata, K AF Cirignano, L Shah, KS Bennett, PR Klugerman, M Dmitryev, Y Squillante, MR Narita, T Bloser, P Grindlay, J Hasegawa, BH Iwata, K TI Pixellated CdZnTe detector for emission/transmission computed tomography SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 9th Symposium on Radiation Measurements and Applications CY MAY 11-14, 1998 CL ANN ARBOR, MICHIGAN ID SYSTEM; CDTE AB A small pixellated CdZnTe array is tested for suitability in a prototype SPECT system designed to acquire both emission and transmission data. Determining the optimum contact design and obtaining performance estimates of single photon acquisition are the primary focus. Flood field and collimated Co-57 sources irradiated the 16 pixel array (5 mm thick and 1.5 mm pixels) to determine photopeak efficiencies and detector response with different event collection techniques. intrinsic full energy peal; efficiency averaged 72% for an 18 keV acceptance window. A small irradiation spot scanned an array region, revealing detector response from nearby pixels. Post processing spectra compare coincident and anti-coincident acquisition. Additionally, current mode tests compare linearity with a CdWO4/Si p-i-n detector. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Radiat Monitoring Devices Inc, Watertown, MA 02172 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Calif San Francisco, Phys Res Lab, S San Francisco, CA 94080 USA. RP Bennett, PR (reprint author), Radiat Monitoring Devices Inc, Watertown, MA 02172 USA. NR 6 TC 5 Z9 5 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 11 PY 1999 VL 422 IS 1-3 BP 216 EP 220 DI 10.1016/S0168-9002(98)01097-3 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 171MY UT WOS:000078868800044 ER PT J AU Nicastro, F Fiore, F Perola, GC Elvis, M AF Nicastro, F Fiore, F Perola, GC Elvis, M TI The equilibrium photoionized absorber in 3C 351 SO ASTROPHYSICAL JOURNAL LA English DT Article DE quasars : individual (3C 351); X-rays : galaxies ID BRIGHT QUASAR SURVEY; X-RAY AB We present two ROSAT Position Sensitive Proportional Counter (PSPC) observations of the radio-loud, lobe-dominated quasar 3C 351, which shows an "ionized absorber" in its X-ray spectrum. The factor of 1.7 change in flux in the similar to 2 years between the observations allows a test of models for this ionized absorber. The absorption feature at similar to 0.7 keV (quasar frame) is present in both spectra but with a lower optical depth when the source intensity-and hence the ionizing flux at the absorber-is higher, in accordance with a simple, single-zone, equilibrium photoionization model. Detailed modeling confirms this agreement quantitativeiy. The maximum response time of 2 years allows us to limit the gas density: n(e) > 2 x 10(4) cm(-3); and the distance R of the ionized gas from the central source is less than 19 pc. This produces a strong test for a photoionized absorber in 3C 351: a factor of 2 flux change in similar to 1 week in this source must show nonequilibrium effects in the ionized absorber. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron Roma, I-00040 Monte Porzio Catone, RM, Italy. SAX Sci Data Ctr, I-00100 Rome, Italy. Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. RP Nicastro, F (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Nicastro, Fabrizio/0000-0002-6896-1364; Fiore, Fabrizio/0000-0002-4031-4157 NR 16 TC 9 Z9 9 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 1999 VL 512 IS 1 BP 136 EP 139 DI 10.1086/306741 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178DM UT WOS:000079251100013 ER PT J AU Nicastro, F Fiore, F Perola, GC Elvis, M AF Nicastro, F Fiore, F Perola, GC Elvis, M TI Ionized absorbers in active galactic nuclei: The role of collisional ionization and time-evolving photoionization SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; galaxies : active; galaxies : Seyfert; X-rays : galaxies ID SEYFERT-1 GALAXY NGC-4051; X-RAY VARIABILITY; WARM ABSORBER; SPECTRAL VARIABILITY; QUASARS; MCG-6-30-15; ABSORPTION; EMISSION; NGC-5548; GAS AB In this paper we explore collisional ionization and time-evolving photoionization in the X-ray-discovered, ionized absorbers in Seyfert galaxies. These absorbers show temporal changes inconsistent with simple equilibrium models. We develop a simple code to follow the temporal evolution of nonequilibrium photoionized gas. As a result several effects appear that are easily observable and that, in fact, may explain otherwise paradoxical behavior. Specifically, we find the following: 1. In many important astrophysical conditions (O VII, O VIII dominant and high [greater than or similar to 10(22.5) cm(-2)] column density) pure collisional and photoionization equilibria can be distinguished with moderate spectral resolution observations, because of a strong absorption structure between 1 and 3 keV. This feature is due mainly to iron L XVII-XIX and neon K IX-X absorption, which is much stronger in collisional models. This absorption structure may be misinterpreted as a flattening of the intrinsic emission spectrum above similar to 1 keV in low-resolution data. 2. In time-evolving nonequilibrium photoionization models the response of the ionization state of the gas to sudden changes of the ionizing continuum is smoothed and delayed at low gas densities (usually up to 10(8) cm(-3)), even when the luminosity increases. The recombination time can be much longer (up to orders of magnitude) than the photoionization timescale. Hence, a photoionized absorber subject to frequent, quick, and consistent changes of ionizing luminosity is likely to be overionized with respect to the equilibrium ionization state. 3. If the changes of the ionizing luminosity are not instantaneous, and the electron density is low enough (the limit depends on the average ionization state of the gas but is usually similar to 10(7) to similar to 10(8) cm(-3)), the ionization state of the gas can continue to increase while the source luminosity decreases, so a maximum in the ionization state of a given element may occur during a minimum of the ionizing intensity (the opposite of the prediction of equilibrium models). 4. Different ions of different elements reach their equilibrium configuration on different timescales, so models in which all ions of all elements are in photoionization equilibrium so often fail to describe active galactic nucleus (AGI) spectral evolution. These properties are similar to those seen in several ionized absorbers in AGNs, properties that had hitherto been puzzling. We applied these models to a high signal-to-noise ratio ROSAT PSPC observation of the Seyfert 1 galaxy NGC 4051. The compressed dynamical range of variation of the ionization parameter U and the ionization delays seen in the ROSAT observations of NGC 4051 may be simply explained by a nonequilibrium photoionization model, giving well-constrained parameters: n(e) = (1.0(-0.5)(+1.2)) x 10(8) cm(-3) and R = (0.74(-0.40)(+0.80)) x 10(16) cm (similar to 3 light-days). C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron Roma, I-00040 Monte Porzio Catone, RM, Italy. Univ Roma TRe, Dipartimento Fis, I-00146 Rome, Italy. RP Nicastro, F (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Nicastro, Fabrizio/0000-0002-6896-1364; Fiore, Fabrizio/0000-0002-4031-4157 NR 46 TC 66 Z9 66 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 1999 VL 512 IS 1 BP 184 EP 196 DI 10.1086/306736 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178DM UT WOS:000079251100019 ER PT J AU Lada, CJ Alves, J Lada, EA AF Lada, CJ Alves, J Lada, EA TI Infrared extinction and the structure of the IC 5146 dark cloud SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; infrared : ISM : continuum; ISM : clouds; ISM : individual (IC 5146) ID COMPLEX; STARS; DUST AB We report deep near-infrared (HK) imaging observations of the dark cloud associated with IC 5146. With an order of magnitude greater sensitivity, we have imaged roughly half the region of the cloud originally surveyed by Lada and coworkers. Using measurements of similar to 2000 stars, we have employed techniques previously developed by Lada and coworkers to construct ordered, uniformly sampled maps of the extinction through this cloud. With the improved sensitivity, we detected approximately 5 times as many heavily extincted stars (i.e., A(v) similar to 20-50 mag) as found in the earlier survey of this same cloud area. Moreover, we were able to produce a Gaussian-smoothed extinction map of the cloud with an angular resolution (30") somewhat more than a factor of 2 higher than achieved in the earlier study. With the increased sensitivity and angular resolution we were also able to measure the average radial column density profile orthogonal to the major axis of this filamentary cloud. Assuming cylindrical symmetry, we modeled this column density gradient and determined that the corresponding volume density profile of the cloud must smoothly fall off as r(-2). To investigate the structure of the cloud on size scales smaller than the effective resolution of our maps, we constructed plots of the relation between the derived mean extinction and its measured dispersion for all the pixels in a series of maps made with varying angular resolution. We find, similar to Lada et al., that the dispersion increases linearly with mean A(v), independent of the angular resolution of our maps. However, although we quantitatively reproduce the earlier results at the same angular resolution (90"), we find the interesting result that the slope of the sigma(Av)-A(v) relation decreases in a systematic fashion with increasing angular resolution. We construct synthetic models of the cloud density distribution and use Monte Carlo techniques to produce artificial extinction maps and investigate the origin of the sigma(Av)-A(v) relations. These models show that both the observed form of the sigma(Av)-A(v) relation and its variation with angular resolution are the natural consequences of a smooth, radially decreasing volume density gradient in a cylindrically symmetric cloud. For a volume density gradient falling off as r(-2), the quantitative agreements between the model predictions and data are excellent. Apparently, these relations can be understood without the need for random fluctuations in the structure of the cloud on small spatial scales. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Florida, Dept Astron, Gainesville, FL 32608 USA. Univ Lisbon, Dept Phys, P-1699 Lisbon, Portugal. RP Lada, CJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 16 TC 104 Z9 104 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 1999 VL 512 IS 1 BP 250 EP 259 DI 10.1086/306756 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178DM UT WOS:000079251100026 ER PT J AU Wood, BE Karovska, M Chen, J Brueckner, GE Cook, JW Howard, RA AF Wood, BE Karovska, M Chen, J Brueckner, GE Cook, JW Howard, RA TI Comparison of two coronal mass ejections observed by EIT and LASCO with a model of an erupting magnetic flux rope SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : activity; Sun : corona; Sun : particle emission; Sun : prominences ID MAGNETOHYDRODYNAMIC SIMULATION; DYNAMICAL EVOLUTION; STREAMER; DISRUPTION; SYSTEM AB We present observations of two coronal mass ejections (CMEs) observed by the LASCO and EIT instruments on board the Solar and Heliospheric Observatory. One was observed on 1997 April 30 and the other on 1997 February 23. The latter CME is accompanied by a spectacular prominence eruption and reaches velocities of about 900 km s(-1), while the former has no apparent accompanying prominence eruption and attains velocities of only about 300 km s(-1). However, the two CMEs are similar in appearance, having bright circular rims that can be interpreted as marking the apexes of expanding magnetic flux ropes, and both can be tracked from their origins near the surface of the Sun out to great distances. We compare the kinematic and morphological properties of these CMEs with an MHD model of an erupting flux rope and find that the CMEs can be successfully modeled in this manner. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Wood, BE (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 22 TC 104 Z9 104 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 1999 VL 512 IS 1 BP 484 EP 495 DI 10.1086/306758 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178DM UT WOS:000079251100047 ER PT J AU Aguirre, AN AF Aguirre, AN TI Dust versus cosmic acceleration SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; dust, extinction; radiative transfer ID INTERSTELLAR GRAPHITE; SPECTRAL OBSERVATIONS; SPIRAL GALAXIES; GRAINS; COBE; EXTINCTION; WHISKERS; EMISSION; CLUSTERS; QUASARS AB Two groups have recently discovered a statistically significant deviation in the fluxes of high-redshift Type Ia supernovae from the predictions of a Friedmann model with a zero cosmological constant. In this Letter, I argue that bright, dusty, starburst galaxies would preferentially eject a dust component with a shallower opacity curve (hence less reddening) and a higher opacity/mass than the observed galactic dust that is left behind. Such dust could cause the falloff in flux at high redshift without violating constraints on reddening or metallicity. The specific model presented is of needle-like dust, which is expected from the theory of crystal growth and has been detected in samples of interstellar dust. Carbon needles with conservative properties can supply the necessary opacity and would very likely be ejected from galaxies as required. The model is not subject to the arguments given in the literature against gray dust but may be constrained by future data from supernova searches done at higher redshift, in clusters, or over a larger frequency range. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM aaguirre@cfa.harvard.edu NR 45 TC 89 Z9 90 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 1999 VL 512 IS 1 BP L19 EP L22 DI 10.1086/311862 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178DP UT WOS:000079251300006 ER PT J AU Ford, EC van der Klis, M Mendez, M van Paradijs, J Kaaret, P AF Ford, EC van der Klis, M Mendez, M van Paradijs, J Kaaret, P TI Measurement of hard lags and coherences in the X-ray flux of accreting neutron stars and comparison with accreting black holes SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; stars : individual (Cygnus X-l, GX 339-4, 4U 1705-44, 4U 0614+09); stars : neutron; X-rays : stars ID CYGNUS X-1; CROSS-SPECTRA; MODELS; CANDIDATES; BINARIES; STATE AB Using the Rossi X-ray Timing Explorer, we have measured lags of the 9-33 keV photons relative to the 2-9 keV photons in the timing noise between 0.01 and 100 Hz in the accreting neutron stars 4U 0614+09 and 4U 1705 - 44. We performed similar measurements on the accreting black hole candidates Cyg X-1 and GX 339-4 as a comparison. During the observations, these sources were all in low (hard) states. We find phase lags of between 0.03 and 0.2 rad in all of these sources, with a variation in frequency much less than expected for a lag constant in time. We also measure a coherence consistent with unity in all sources. As already noted for the black hole candidates, these data are inconsistent with simple Comptonization models invoking a constant time delay. Comptonization in a nonuniform medium can perhaps explain the lags. However, the magnitudes of the lags imply that the hot electron gas extends to more than 10(3) Schwarzschild radii. This may constitute an energy problem. We argue that while a large hot cloud is possible for black holes, which may hide some of their accretion energy in advection, such a distribution may not be possible for neutron stars, in which all the accretion energy is eventually released at the neutron star surface. This casts doubt on the Comptonization model, although the energy problem may be resolved, for example, by a wind from the inner disk. C1 Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Natl Univ La Plata, Fac Ciencias Astron & Geofis, RA-1900 La Plata, Argentina. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Ford, EC (reprint author), Univ Amsterdam, Astron Inst Anton Pannekoek, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. RI Mendez, Mariano/C-8011-2012 OI Mendez, Mariano/0000-0003-2187-2708 NR 39 TC 32 Z9 33 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 1999 VL 512 IS 1 BP L31 EP L34 DI 10.1086/311863 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178DP UT WOS:000079251300009 ER PT J AU Davis, JL Mitrovica, JX Scherneck, HG Fan, R AF Davis, JL Mitrovica, JX Scherneck, HG Fan, R TI Investigations of Fennoscandian glacial isostatic adjustment using modern sea level records SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID COMPUTING 3-DIMENSIONAL DEFORMATIONS; SPECTRAL FORMALISM; SURFACE LOADS; UPLIFT AB We present a new method for determining the rates from a network of regional tide gauge data. The method involves using a model for the sea level observations (annual averages of relative sea level) that explicitly includes a term for the interannual sealevel variations, which are assumed to be constant for all sites in the network. The resulting simultaneous analysis of all the sea level observations yields sea level rates which are biased by the unknown temporal slope of the interannual variations. By differencing sea level rate estimates with respect to one site, "site-referenced" sea level rates are calculated which are free from this bias. The differencing procedure also removes any signal due to a common sea level rate, such as might be associated with eustatic sea level rise. The resulting site-referenced sea level rates therefore in principle reflect only the relative vertical crustal motions of the tide gauge sites with respect to the geoid. These site-referenced sea level rates represent a potentially more accurate data set than have previously been used for sea level studies. We have used these rates to investigate glacial isostatic adjustment (GIA) in Fennoscandia. Specifically, we have used the site-referenced sea level rates within the Baltic Sea to estimate adjustments to the ice history and Earth model which are used to calculate vertical rates of adjustment due to GIA, a method never before used for Fennoscandia. The parameters selected were lithospheric thickness, the viscosities of (assumed isoviscous) upper and lower mantles, and a Fennoscandian ice thickness scaling parameter. We present the results of this estimation procedure for a specific test ice model. We also find evidence that the sea level record for the site nearest the center of uplift, Furuogrund, may be contaminated by systematic errors of unknown origin. Data from this site have previously been used to determine a rate for the maximum uplift that we find is perhaps 1 mm yr(-1), or similar to 10%, too large. C1 Harvard Smithsonian Ctr Astrophys, Radio & Geoastron Div, Cambridge, MA 02138 USA. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Onsala Space Observ, S-43992 Onsala, Sweden. Royal Inst Technol, Dept Geodesy & Photogrammetry, S-10044 Stockholm, Sweden. RP Harvard Smithsonian Ctr Astrophys, Radio & Geoastron Div, 60 Garden St,MS 42, Cambridge, MA 02138 USA. EM jdavis@cfa.harvard.edu RI Davis, James/D-8766-2013 OI Davis, James/0000-0003-3057-477X NR 39 TC 27 Z9 27 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD FEB 10 PY 1999 VL 104 IS B2 BP 2733 EP 2747 DI 10.1029/1998JB900057 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 165YL UT WOS:000078549400007 ER PT J AU De Silva, AM Dittus, WPJ Amerasinghe, PH Amerasinghe, FP AF De Silva, AM Dittus, WPJ Amerasinghe, PH Amerasinghe, FP TI Serologic evidence for an epizootic dengue virus infecting toque macaques (Macaca sinica) at Polonnaruwa, Sri Lanka SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID PRIMATE POPULATION; NATURAL-POPULATION; AEDES-ALBOPICTUS; TRANSMISSION; EVOLUTION; MOSQUITOS; MONKEYS; FEVER AB Dengue is one of the most rapidly emerging diseases in the tropics. Humans are the principal reservoir of dengue viruses. It is unclear if nonhuman primates also serve as a reservoir of human dengue viruses under certain conditions. In this study, a cross-sectional serologic survey was carried out to characterize the pattern of transmission of a recently identified dengue virus among toque macaques in Sri Lanka. The results indicated that an epizootic dengue virus was active among the macaques. A single epizootic had taken place between October 1986 and February 1987 during which 94% of the macaques within the 3 km(2) study site were exposed to the virus. The epizootic was highly focal in nature because macaques living 5 km from the study population were not exposed to the virus. The transmission of dengue viruses among macaques in the wild may have important public health implications. C1 Yale Univ, Sch Med, Dept Internal Med, Rheumatol Sect, New Haven, CT 06510 USA. Smithsonian Inst, Natl Zool Pk, Dept Zool Res, Washington, DC 20008 USA. Inst Fundamental Studies, Kandy, Sri Lanka. Univ Peradeniya, Fac Sci, Dept Zool, Peredeniya, Sri Lanka. RP De Silva, AM (reprint author), Univ N Carolina, Dept Microbiol & Immunol, Campus Box 7290, Chapel Hill, NC 27599 USA. NR 25 TC 17 Z9 18 U1 0 U2 5 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DRIVE SUITE 130, MCLEAN, VA 22101 USA SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD FEB PY 1999 VL 60 IS 2 BP 300 EP 306 PG 7 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA 171RW UT WOS:000078878700025 PM 10072155 ER PT J AU Pandolfi, JM AF Pandolfi, JM TI Response of Pleistocene coral reefs to environmental change over long temporal scales SO AMERICAN ZOOLOGIST LA English DT Article; Proceedings Paper CT Symposium on Coral Reefs and Environmental Changes - Adaptation, Acclimation, or Extinction at the Annual Meeting of the Society-for-Comparative-and-Integrative-Biology CY JAN 03-07, 1998 CL BOSTON, MASSACHUSETTS SP Soc Comparative & Integrative Biol ID COMMUNITY STRUCTURE; HUON-PENINSULA; HABITAT DESTRUCTION; NEW-GUINEA; DISTURBANCE; RECRUITMENT; DYNAMICS; EXTINCTION; DIVERSITY; ABUNDANCE AB TWO studies from the Pleistocene coral reef fossil record demonstrate the sensitivity of reef communities to both local environmental parameters and habitat reduction. In the first study, Pleistocene reef coral assemblages from Papua New Guinea show pronounced constancy in taxonomic composition and species diversity between 125 and 30 ka (thousand years). Spatial differences in reef coral community composition during successive high stands of sea level were greater among sites of the same age than among reefs of different ages, even though global changes in sea level, atmospheric CO2 concentration, tropical benthic habitat area, and temperature varied at each high sea level stand. Thus, local environmental variation associated with runoff from the land had greater influence on reef coral community composition than variation in global climate and sea level, Proportional sampling from a regional species pool does not explain the temporal persistence and local factors likely played a major role. Examination of coral reef response to global change should not only involve regional diversity patterns but also local ecological factors, and the interactive effects of local and global environmental change. In the second study, Pleistocene extinction of two widespread, strictly insular species of Caribbean reef corals, Pocillopora cf. palmata (Geister, 1975) and an organ-pipe growth form of the Montastraea "annularis" species complex, was natural and did not involve gradual decrease in range and abundance, but was sudden (thousands of years) throughout the entire range. One explanation is that sea level drop at the Last Glacial Maximum (LGM-18 ka) resulted in a threshold of habitat reduction, and caused disruption of coral metapopulation structure. Threshold effects predicted by metapopulation dynamics may also explain the apparent paradox of the large amount of degraded modern reef habitat without any known modern-day reef coral extinctions, The rapid extinction of widespread Pleistocene species emphasizes the vulnerability of reef corals in the face of present rapid environmental and climatic change. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Paleobiol, MRC 121, Washington, DC 20560 USA. RP Pandolfi, JM (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Paleobiol, MRC 121, Washington, DC 20560 USA. EM pandolfi.john@nmnh.si.edu RI Pandolfi, John/A-3121-2009 OI Pandolfi, John/0000-0003-3047-6694 NR 83 TC 76 Z9 80 U1 1 U2 21 PU AMER SOC ZOOLOGISTS PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0003-1569 J9 AM ZOOL JI Am. Zool. PD FEB PY 1999 VL 39 IS 1 BP 113 EP 130 PG 18 WC Zoology SC Zoology GA 180HJ UT WOS:000079379800010 ER PT J AU Schaeff, CM Boness, DJ Bowen, WD AF Schaeff, CM Boness, DJ Bowen, WD TI Female distribution, genetic relatedness, and fostering behaviour in harbour seals, Phoca vitulina SO ANIMAL BEHAVIOUR LA English DT Article ID RIGHT-WHALES EUBALAENA; NORTH-ATLANTIC; HUMAN DNA; POPULATION; ADOPTION AB Although harbour seals may not recognize their relatives, relatives could be chosen preferentially for fostering (i.e. kin selection) if harbour seals display natal philopatry coupled with breeding site fidelity, and thus kin are clustered within the colony. We used behavioural and genetic data to investigate population structure within the Sable Island breeding colony and to test whether harbour seals tend to foster related pups. Adult females on Sable Island showed a high level of breeding-colony site fidelity but low levels of within-colony site fidelity both within and between years. Similarly, although lactating females showed a clumped distribution, group composition was highly variable, suggesting that this study colony was not composed of groups of related animals, DNA fingerprint data supported the hypothesis that female distribution within the colony was not correlated with genetic relatedness. Furthermore, the mean DNA band sharing among foster dyads did not differ significantly from that for unrelated animals. These results indicate that among harbour seals, related pups are not usually chosen preferentially for fostering and hence, kin selection is not likely to be influencing the occurrence of this behaviour. (C) 1999 The Association for the Study of Animal Behaviour. C1 American Univ, Dept Biol, Washington, DC 20016 USA. Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. Fisheries & Oceans Canada, Bedford Inst Oceanog, Marine Fisheries Div, Dartmouth, NS B2Y 4A2, Canada. RP American Univ, Dept Biol, 4400 Massachusetts Ave NW, Washington, DC 20016 USA. EM schaeff@american.edu RI Bowen, William/D-2758-2012; OI Schaeff, Catherine/0000-0003-3728-9402 NR 30 TC 24 Z9 25 U1 0 U2 12 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0003-3472 EI 1095-8282 J9 ANIM BEHAV JI Anim. Behav. PD FEB PY 1999 VL 57 BP 427 EP 434 DI 10.1006/anbe.1998.1001 PN 2 PG 8 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA 168LX UT WOS:000078695200019 ER PT J AU Miller, B Ralls, K Reading, RP Scott, JM Estes, J AF Miller, Brian Ralls, Katherine Reading, Richard P. Scott, J. Michael Estes, James TI Biological and technical considerations of carnivore translocation: a review SO ANIMAL CONSERVATION LA English DT Review AB Carnivore translocations are usually risky and expensive, and a number of biological and non-biological factors can influence success. Biological considerations include knowledge of genetics, demographics, behavior, disease, and habitat requirements. This information is critical for determining if the translocation should be attempted, if it could be successful, and how it could be implemented in an efficient and effective manner. We stress that individual species will vary in their responses, and ideas should be tested scientifically. The technical considerations of translocation are closely related to the biological questions. They include legal framework, fiscal and intellectual resources, monitoring capacity, goals of the translocation, logistic challenges, and organizational structure of decision-making. We do not discuss socio-economic aspects of translocation because those challenges require detailed discussion in a separate paper. We suggest that because large carnivores often play key roles in regulating ecological interactions between trophic levels, restoring them is more than a single-species activity. By restoring carnivores in viable numbers, we can take a large step toward recovering ecological integrity of geographically extensive landscapes. C1 [Miller, Brian; Reading, Richard P.] Denver Zoo, Dept Conservat Biol, Denver, CO 80205 USA. [Ralls, Katherine] Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. [Scott, J. Michael] Univ Idaho, Coll Forestry Wildlife & Range Sci, Moscow, ID 83843 USA. [Estes, James] Univ Calif Santa Cruz, Santa Cruz, CA 96064 USA. RP Miller, B (reprint author), Denver Zoo, Dept Conservat Biol, Denver, CO 80205 USA. EM zooconservation@denverzoo.org NR 112 TC 73 Z9 76 U1 3 U2 33 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1367-9430 J9 ANIM CONSERV JI Anim. Conserv. PD FEB PY 1999 VL 2 IS 1 BP 59 EP 68 DI 10.1111/j.1469-1795.1999.tb00049.x PG 10 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA V71EG UT WOS:000204810600008 ER PT J AU Zotz, G Thomas, V AF Zotz, G Thomas, V TI How much water is in the tank? Model calculations for two epiphytic bromeliads SO ANNALS OF BOTANY LA English DT Article DE epiphytes; water relations; Barro Colorado Island; bromeliads; water tanks; phytotelmata AB Water-impounding foliage (= tank) characterizes many bromeliad species but, to date, a quantitative evaluation of the effectiveness of these structures to bridge rainless periods is not available. We present a model that analyses the capacity of these phytotelmata to supply moisture to the bromeliad as a function of plant size, and parameterize it for two epiphyte species, Tillandsia fasciculata and Guzmania monostachya. All parameters related to the recharging of a tank (e.g. catchment area, or tank capacity) and those related to water loss from the tank (e.g. tank water surface, or water absorption from the tank by the plant) changed with plant size. For both species a similar qualitative size-related pattern emerged: smaller individuals dried out much faster than larger conspecifics. Modelling the changes in tank water content for an entire year revealed that in the seasonal climate of Barro Colorado Island, Panama, tanks of smaller plants (1 g d. wt) are expected to lack water for up to 110 d (in T. fasciculata). Regardless of plant size, individuals of G, monostachya were consistently more efficient than T. fasciculata in maintaining moisture in their tanks. Our results provide insight into the limitations of water-impounding tanks as an adaptation to cope with an intermittent water supply typical for epiphytic habitats. These limitations are particularly pronounced for smaller individuals. (C) 1999 Annals of Botany Company. C1 Univ Wurzburg, Lehrstuhl Bot 2, D-97082 Wurzburg, Germany. Smithsonian Trop Res Inst, Balboa, Panama. RP Zotz, G (reprint author), Univ Wurzburg, Lehrstuhl Bot 2, Julius von Sachs Pl 3, D-97082 Wurzburg, Germany. NR 22 TC 54 Z9 55 U1 0 U2 21 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0305-7364 J9 ANN BOT-LONDON JI Ann. Bot. PD FEB PY 1999 VL 83 IS 2 BP 183 EP 192 DI 10.1006/anbo.1998.0809 PG 10 WC Plant Sciences SC Plant Sciences GA 164RP UT WOS:000078477600009 ER PT J AU Riess, AG Kirshner, RP Schmidt, BP Jha, S Challis, P Garnavich, PM Esin, AA Carpenter, C Grashius, R Schild, RE Berlind, PL Huchra, JP Prosser, CF Falco, EE Benson, PJ Briceno, C Brown, WR Caldwell, N Dell'Antonio, IP Filippenko, AV Goodman, AA Grogin, NA Groner, T Hughes, JP Green, PJ Jansen, RA Kleyna, JT Luu, JX Macri, LM McLeod, BA McLeod, KK McNamara, BR McLean, B Milone, AAE Mohr, JJ Moraru, D Peng, C Peters, J Prestwich, AH Stanek, KZ Szentgyorgyi, A Zhao, P AF Riess, AG Kirshner, RP Schmidt, BP Jha, S Challis, P Garnavich, PM Esin, AA Carpenter, C Grashius, R Schild, RE Berlind, PL Huchra, JP Prosser, CF Falco, EE Benson, PJ Briceno, C Brown, WR Caldwell, N Dell'Antonio, IP Filippenko, AV Goodman, AA Grogin, NA Groner, T Hughes, JP Green, PJ Jansen, RA Kleyna, JT Luu, JX Macri, LM McLeod, BA McLeod, KK McNamara, BR McLean, B Milone, AAE Mohr, JJ Moraru, D Peng, C Peters, J Prestwich, AH Stanek, KZ Szentgyorgyi, A Zhao, P TI BVRI light curves for 22 Type Ia supernovae SO ASTRONOMICAL JOURNAL LA English DT Article DE supernovae : general ID HUBBLE DIAGRAM; STANDARD CANDLES; ABSOLUTE MAGNITUDE; TIME DILATION; GALAXIES; PHOTOMETRY; CONSTANT; CATALOG; MOTION; SHAPES AB We present 1210 Johnson/Cousins B, V, R, and I photometric observations of 22 recent Type Ia supernovae (SNe Ia): SNe 1993ac, 1993ae, 1994M, 1994S, 1994T, 1994Q, 1994ae, 1995D, 1995E, 1995al, 1995ac, 1995ak, 1995bd, 1996C, 1996X, 1996Z, 1996ab, 1996ai, 1996bk, 1996bl, 1996bo, and 1996bv. Most of the photometry was obtained at the Fred Lawrence Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics in a cooperative observing plan aimed at improving the database for SNe Ia. The redshifts of the sample range from cz = 1200 to 37,000 km s(-1) with a mean of ct = 7000 km s(-1). C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Weston, ACT 2611, Australia. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Fred Lawrence Whipple Observ, Amado, AZ 85645 USA. Wellesley Coll, Dept Astron, Whitin Observ, Wellesley, MA 02481 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Whipple Observ, Multiple Mirror Telescope Observ, Amado, AZ 85645 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Riess, AG (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. RI Goodman, Alyssa/A-6007-2010; OI Goodman, Alyssa/0000-0003-1312-0477; Schmidt, Brian/0000-0001-6589-1287 NR 85 TC 441 Z9 441 U1 2 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD FEB PY 1999 VL 117 IS 2 BP 707 EP 724 DI 10.1086/300738 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 172CT UT WOS:000078905300005 ER PT J AU Fesen, RA Gerardy, CL Filippenko, AV Matheson, T Chevalier, RA Kirshner, RP Schmidt, BP Challis, P Fransson, C Leibundgut, B Van Dyk, SD AF Fesen, RA Gerardy, CL Filippenko, AV Matheson, T Chevalier, RA Kirshner, RP Schmidt, BP Challis, P Fransson, C Leibundgut, B Van Dyk, SD TI Late-time optical and ultraviolet spectra of SN 1979C and SN 1980K SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 4321, NGC 6946); supernovae : individual (SN 1979C, SN 1980K) ID RICH SUPERNOVA REMNANT; II SUPERNOVAE; LIGHT CURVES; RADIO-EMISSION; SN-1980K; RECOVERY; NGC-6946; EJECTA; NOVAE; 1988Z AB A low-dispersion Keck I spectrum of SN 1980K taken in 1995 August (t = 14.8 yr after explosion) and a spectrum taken in 1997 November (t = 17.0 yr) at the MDM Observatory show broad 5500 km s(-1) emission lines of H alpha, [O I] 6300, 6364 Angstrom, and [O II] 7319, 7330 Angstrom. Weaker but similarly broad lines detected include [Fe II] 7155 Angstrom,, [S II] 4068, 4072 Angstrom, and a blend of [Fe II] lines at 5050-5400 Angstrom. The presence of strong [S II] 4068, 4072 Angstrom emission but a lack of [S II] 6716, 6731 Angstrom emission suggests electron densities of 10(5)-10(6) cm(-3) From the 1997 spectrum, we estimate an H alpha flux of (1.3 +/- 0.2) x 10(-15) ergs cm(-2) s(-1), indicating a 25% decline from the 1987-1992 levels during the period 1994 to 1997, possibly related to a reported decrease in its nonthermal radio emission. A 1993 May, Multiple Mirror Telescope spectrum of SN 1979C (t = 14.0 yr) shows a somewhat different spectrum from that of SN 1980K. Broad, 6000 km s(-1) emission lines are also seen but with weaker H alpha, stronger [O III] 4959, 5007 Angstrom, more highly clumped [O I] and [O II] line profiles, no detectable [Fe II] 7155 Angstrom emission, and a faint but very broad emission feature near 5750 Angstrom. A 1997 Hubble Space Telescope Faint Object Spectrograph, near-UV spectrum (2200-4500 Angstrom) shows strong lines of C II] 2324, 2325 Angstrom, [O II] 2470 Angstrom, and Mg II 2796, 2803 Angstrom, along with weak [Ne III] 3969 Angstrom [S II] 4068, 4072 Angstrom, and [O III] 4363 Angstrom emissions. The UV emission lines show a double-peak profile with the blueward peak substantially stronger than the red, suggesting dust extinction within the expanding ejecta CE(B-V)= 0.11-0.16 mag]. The lack of detectable [O II] 3726, 3729 Angstrom emission, together with [O III] lambda lambda(4959 + 5007)/lambda 4363 similar or equal to 4, implies electron densities 10(6)-10(7) cm(-3). These Type II linear supernovae (SNe II-L) spectra show general agreement with the lines expected in a circumstellar interaction model, but the specific models that are available show several differences with the observations. High electron densities (10(5)-10(7) cm(-3)) result in stronger collisional de-excitation than assumed in the models, thereby explaining the absence of several moderate to strong predicted lines such as [O II] 3726, 3729 Angstrom, [N II] 6548, 6583 Angstrom, and [S II] 6716, 6731 Angstrom. Interaction models are needed that are specifically suited to these supernovae. We review the overall observed range of late-time SNe II-L properties and briefly discuss their properties relative to young, ejecta-dominated Galactic supernova remnants. C1 Dartmouth Coll, Dept Phys & Astron, Wilder Lab 6127, Hanover, NH 03755 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Weston, ACT 2611, Australia. Stockholm Observ, SE-13336 Saltsjobaden, Sweden. European So Observ, D-85748 Garching, Germany. CALTECH, Infared Proc & Anal Ctr, Pasadena, CA 91125 USA. RP Fesen, RA (reprint author), Dartmouth Coll, Dept Phys & Astron, Wilder Lab 6127, Hanover, NH 03755 USA. OI Schmidt, Brian/0000-0001-6589-1287 NR 51 TC 44 Z9 44 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD FEB PY 1999 VL 117 IS 2 BP 725 EP 735 DI 10.1086/300751 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 172CT UT WOS:000078905300006 ER PT J AU Garcia-Sanchez, J Preston, RA Jones, DL Weissman, PR Lestrade, JF Latham, DW Stefanik, RP AF Garcia-Sanchez, J Preston, RA Jones, DL Weissman, PR Lestrade, JF Latham, DW Stefanik, RP TI Stellar encounters with the Oort cloud based on Hipparcos data SO ASTRONOMICAL JOURNAL LA English DT Article DE comets : general; solar neighborhood; solar system : general; stars : kinematics ID GROUND-BASED MEASUREMENTS; INDIVIDUAL RADIAL-VELOCITIES; SOLAR-TYPE STARS; STANDARD STARS; ASTROPHYSICAL BINARIES; COMET SHOWERS; DWARF STARS; CATALOG; KINEMATICS; SYSTEM AB We have combined Hipparcos proper-motion and parallax data for nearby stars with ground-based radial velocity measurements to find stars that may have passed (or will pass) close enough to the Sun to perturb the Oort cloud. Close stellar encounters could deflect large numbers of comets into the inner solar system, which would increase the impact hazard at Earth. We find that the rate of close approaches by star systems (single or multiple stars) within a distance D (in parsecs) from the Sun is given by N = 3.5D(2.12) MYr(-1), less than the number predicted by a simple stellar dynamics model. However, this value is clearly a lower limit because of observational incompleteness in the Hipparcos data set. One star, Gliese 710, is estimated to have a closest approach of less than 0.4 pc 1.4 Myr in the future, and several stars come within 1 pc during a +/- 10 Myr interval. We have performed dynamical simulations that show that none of the passing stars perturb the Oort cloud sufficiently to create a substantial increase in the long-period comet flux at Earth's orbit. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Observ Paris, Sect Meudon, F-92195 Meudon, France. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Barcelona, Dept Astron & Meteorol, E-08028 Barcelona, Spain. RP Garcia-Sanchez, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 93 TC 44 Z9 44 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD FEB PY 1999 VL 117 IS 2 BP 1042 EP 1055 DI 10.1086/300723 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 172CT UT WOS:000078905300031 ER PT J AU Rauch, KP Holman, M AF Rauch, KP Holman, M TI Dynamical chaos in the Wisdom-Holman integrator: Origins and solutions SO ASTRONOMICAL JOURNAL LA English DT Article DE celestial mechanics, stellar dynamics; chaos; methods : numerical ID N-BODY PROBLEM; RADIATION PRESSURE; SYMPLECTIC MAPS; ORBITS; COMETS; BELT AB We examine the nonlinear stability of the Wisdom-Holman (WH) symplectic mapping applied to the integration of perturbed, highly eccentric (e greater than or similar to 0.9) two-body orbits. We find that the method is unstable and introduces artificial chaos into the computed trajectories for this class of problems, unless the step size chosen is small enough that periapse is always resolved, in which case the method is generically stable. This "radial orbit instability" persists even for weakly perturbed systems. Using the Stark problem as a fiducial test case, we investigate the dynamical origin of this instability and argue that the numerical chaos results from the overlap of step-size resonances; interestingly, for the Stark problem many of these resonances appear to be absolutely stable. We similarly examine the robustness of several alternative integration methods: a time-regularized version of the WH mapping suggested by Mikkola; the potential-splitting (PS) method of Duncan, Levison, & Lee; and two original methods incorporating approximations based on Stark motion instead of Keplerian motion (compare Newman et al.). The two fixed point problem and a related, more general problem are used to conduct a comparative test of the various methods for several types of motion. Among the algorithms tested, the time-transformed WH mapping is clearly the most efficient and stable method of integrating eccentric, nearly Keplerian orbits in the absence of close encounters. For test particles subject to both high eccentricities and very close encounters, we find an enhanced version of the PS method - incorporating time regularization, force-center switching, and an improved kernel function - to be both economical and highly versatile. We conclude that Stark-based methods are of marginal utility in N-body type integrations. Additional implications for the symplectic integration of N-body systems are discussed. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Rauch, KP (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NR 29 TC 49 Z9 50 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD FEB PY 1999 VL 117 IS 2 BP 1087 EP 1102 DI 10.1086/300720 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 172CT UT WOS:000078905300035 ER PT J AU Kerp, J Burton, WB Egger, R Freyberg, MJ Hartmann, D Kalberla, PMW Mebold, U Pietz, J AF Kerp, J Burton, WB Egger, R Freyberg, MJ Hartmann, D Kalberla, PMW Mebold, U Pietz, J TI A search for soft X-ray emission associated with prominent high-velocity-cloud complexes SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM : clouds; galaxy : halo; galaxy : kinematics and dynamics; X-rays : ISM ID LOCAL INTERSTELLAR-MEDIUM; H-I; GALACTIC DISK; ROSAT SURVEY; DIFFUSE; HALO; GALAXY; PSPC; SPECTRUM; OBJECTS AB We correlate the ROSAT 1/4 keV all-sky survey with the Leiden/Dwingeloo HI survey, looking for soft X-ray sig natures of prominent high-velocity-cloud (HVC) complexes. We study the transfer 1/4 keV photons through the interstellar medium in order to distinguish variations in the soft X-ray data are modelled as a combination of emission from the Local Hot Bubble (LHB) and emission from a distant plasma in the galactic halo and extragalactic sources. The X-ray radiation intensity of the galactic halo and extragalactic X-ray background is modulated by the photoelectric absorption of the intervening galactic interstellar matter. We show that large- and small-scale intensity variations of the 1/4 keV SXRB are caused by photoelectric absorption which is predominantly traced by the total N-HI distribution. The extensive coverage of the two surveys supports evidence for a hot, X-ray emitting corona. We show that this leads to a good representation of the SXRB observations. For four large areas on the sky, we search for regions where the modelled and observed X-ray emission differ. We find that there is excess X-ray emission towards regions near HVC complexes C, D, and GCN. We suggest that the excess X-ray emission is positionally correlated with the high-velocity clouds. Some lines of sight towards HVCs also pass through significant amounts of intermediate-velocity gas, so we cannot constrain the possible role played by IVC gas in these directions of HVC and IVC overlap, in determining the X-ray excesses. C1 Univ Bonn, Inst Radioastron, D-53121 Bonn, Germany. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kerp, J (reprint author), Univ Bonn, Inst Radioastron, Hugel 71, D-53121 Bonn, Germany. NR 70 TC 32 Z9 32 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD FEB PY 1999 VL 342 IS 1 BP 213 EP 232 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 164LJ UT WOS:000078465400024 ER PT J AU Kramer, C Alves, J Lada, CJ Lada, EA Sievers, A Ungerechts, H Walmsley, CM AF Kramer, C Alves, J Lada, CJ Lada, EA Sievers, A Ungerechts, H Walmsley, CM TI Depletion of CO in a cold dense cloud core of IC 5146 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM : molecules; ISM : kinematics and dynamics; ISM : individual objects : IC 5146; ISM : dust, extinction; ISM : clouds; ISM : abundances ID DARK CLOUD; INTERSTELLAR CLOUDS; CARBON-MONOXIDE; MOLECULAR CLOUDS; GAS; ABSORPTION; RESOLUTION; EXTINCTION; TURBULENCE; ABUNDANCES AB We have used the IRAM 30m telescope to map the (CO)-O-18(1-->0) and (2-->1) transitions in a region of 0.5 x 0.5 pc(2) (200 " x 200 ") in the nearby (460 pc distance) molecular cloud IC 5146 at resolutions of down to 0.025 pc. Additionally, we have observed the corresponding (CO)-O-17 transitions towards 24 positions in the central region of the cloud as a check on optical depth effects. On the basis of these observations, we conclude that the (CO)-O-18 emission observed by us is optically thin and that the observed (CO)-O-18(2-->1)/(1-->0) ratio is consistent with gas at 10 K and density in the range 10(4) to 10(5) cm(-3). We have estimated (CO)-O-18 column densities over the region mapped, using an LVG program to correct for excitation effects; and have compared them, at the same spatial resolution of 30 ", with the dust extinction derived from the NIR images of Lada et al. (1998). From this, we find a roughly constant, though with considerable dispersion, ratio of (CO)-O-18 column density to visual extinction (Av) in directions with Av less than similar to 10 magnitudes. The ratio is compatible with previous determinations of the [(CO)-O-18]/[H-2] abundance ratio, e.g. 1.7 10(-7) as obtained by Frerking et al. (1982). At extinctions higher than similar to 10 magnitudes, however, there is a systematic fall-off in the ratio N((CO)-O-18)/A(V) which we attribute to depletion of (CO)-O-18 onto dust ice mantles within the dense, n greater than or similar to 10(4) cm(-3), and cold, T-dust less than or similar to 15 K, T-gas similar to 10 K, core interior. This fall-off is also seen, though with less statistical significance, in our observed dependence of N((CO)-O-17)/A(V) with A(V). We thus think it unlikely that optical depth effects are influencing our conclusions. We have additionally made pointed (CO)-O-18(1-->0)) and (2-->1) observations towards 94 background stars with extinction greater than 10 magnitudes from the study of Lada et al. (1994). These in general confirm our mapping results. C1 Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Florida, Dept Astron, Gainesville, FL 32608 USA. IRAM, E-18012 Granada, Spain. Osservatorio Astrofis Arcetri, I-50125 Florence, Italy. RP Kramer, C (reprint author), Univ Cologne, Inst Phys 1, Zulpicher Str 77, D-50937 Cologne, Germany. EM kramer@ph1.uni-koeln.de NR 37 TC 104 Z9 104 U1 1 U2 2 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD FEB PY 1999 VL 342 IS 1 BP 257 EP 270 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 164LJ UT WOS:000078465400026 ER PT J AU Di Matteo, V Reale, F Peres, G Golub, L AF Di Matteo, V Reale, F Peres, G Golub, L TI Analysis and comparison of loop structures imaged with NIXT and Yohkoh/SXT SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE Sun : X-rays, gamma rays; Sun : corona ID X-RAY-TELESCOPE; CORONAL STRUCTURES; SOLAR CORONA; MODELS AB We analyze and compare five coronal regions simultaneously observed by NIXT and Yohkoh/SXT on April 12, 1993, The compact loop structures (length similar to 10(9) cm) imaged in three regions with NIXT and with SXT have a good general morphological correspondence. A large scale(approximate to 1.7 x 10(10) cm) and an intermediate scale (approximate to 5 x 10(9) cm) structure observed in the NIXT image have no obvious counterpart in the SXT image. The pressure of the loop plasma detected by NIXT is derived from the brightness profile along the loops by applying a method based on loop models. The pressure of the loop plasma in the SXT band has also been derived from loop models on the basis of the temperature obtained from the standard Yohkoh data analysis. NIXT pressures are systematically lower than those found with SXT. By comparing the measured total loop luminosity to that expected on the basis of loop models, we constrain quantitatively the volume filling factor of the plasma emitting respectively in the NIXT and SXT bands. The filling factors obtained in the NIXT band for the compact and intermediate loops are very low (10(-3) - 10(-2)), but they are of the order of unity for the large structure. The low filling factors suggest a strong loop filamentation. The filling factors for the compact structures are instead of the order of unity in the SXT band. We discuss our results and propose a scenario fur their interpretation. C1 Univ Palermo, Dipartimento Sci Fis & Astron, Sez Astron, I-90134 Palermo, Italy. Osservatorio Astron, I-90134 Palermo, Italy. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Univ Palermo, Dipartimento Sci Fis & Astron, Sez Astron, Piazza Parlamento 1, I-90134 Palermo, Italy. EM dimatteo@oapa.astropa.unipa.it; reale@oapa.astropa.unipa.it; peres@oapa.astropa.unipa.it; golub@corona.harvard.edu OI Reale, Fabio/0000-0002-1820-4824; Golub, Leon/0000-0001-9638-3082 NR 14 TC 11 Z9 11 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD FEB PY 1999 VL 342 IS 2 BP 563 EP 574 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 168QH UT WOS:000078703400028 ER PT J AU Zangrilli, L Nicolosi, P Poletto, G Noci, G Romoli, M Kohl, JL AF Zangrilli, L Nicolosi, P Poletto, G Noci, G Romoli, M Kohl, JL TI Latitudinal properties of the Lyman alpha and O VI profiles in the extended solar corona SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE line : profiles; Sun : corona; Sun : solar wind; Sun : UV radiation ID FREQUENCY ALFVEN WAVES; STRAY-LIGHT; WIND; SPECTROMETER; ACCELERATION; MODEL AB We have analysed the latitudinal properties of the profiles of the H I Lyman a line at 1215.6 Angstrom and of the O VI doublet at 1031.9 Angstrom and 1037.6 Angstrom in the extended solar corona, between 1.5 R. and 2.0 R.. Observations have been performed with the Ultra Violet Coronagraph Spectrometer (UVCS) on board the ESA-NASA solar satellite SOHO (SOlar and Heliospheric Observatory). The results show that these lines have quite a different behaviour with latitude: the Ly ct line has larger full width at half maximum (FWHM) values in the streamer region and narrower ones towards polar latitudes, while the O VI lines have a minimum FWHM at the center of the streamer, which almost steadily increases towards polar regions. The observations have been analysed looking also for an interpretation in terms of selective heating mechanisms. The implications of our results for coronal heating theories are also examined. In particular we discuss the possibility for the presence of the ion-cyclotron coronal heating mechanism. Moreover, we point out an interesting correlation between the intensity of the coronal lines and their widths, which may be relevant to the open question of the different morphological features visible in the Ly alpha and O VI lines. C1 Univ Padua, Dipartimento Ingn Elettron & Informat, I-35131 Padua, Italy. Ist Nazl Fis Mat, Unita Padova, Padua, Italy. Osserv Astrofis Arcetri, I-50125 Florence, Italy. Univ Florence, I-50125 Florence, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Zangrilli, L (reprint author), Univ Padua, Dipartimento Ingn Elettron & Informat, I-35131 Padua, Italy. EM zangrilli@pd.astro.it RI Romoli, Marco/H-6859-2012 NR 28 TC 25 Z9 25 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD FEB PY 1999 VL 342 IS 2 BP 592 EP 600 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 168QH UT WOS:000078703400031 ER PT J AU Ceccarelli, C Caux, E Loinard, L Castets, A Tielens, AGGM Molinari, S Liseau, R Saraceno, P Smith, H White, G AF Ceccarelli, C Caux, E Loinard, L Castets, A Tielens, AGGM Molinari, S Liseau, R Saraceno, P Smith, H White, G TI Water line emission in low-mass protostars SO ASTRONOMY & ASTROPHYSICS LA English DT Letter DE stars : formation; ISM : jets and outflows; ISM : individual objects; infrared : ISM : lines and bands; radiative transfer; ISM : molecules ID INTERSTELLAR; SHOCKS; CLOUDS AB Using the Long Wavelength Specrometer aboard ISO, we have detected far infrared rotational H2O emission lines in five low-mass young stellar objects in a survey of seven such sources. The total H2O fluxes are well correlated with the 1.3 mm continuum fluxes, but - surprisingly - not with the SiO millimeter emission originating in the outflows, suggesting that the water emission arises in the circumstellar envelopes rather than in the outflows. In two of the sources, NGC1333-LRAS4 and IRAS 16293-2422, we measured about ten H2O lines, and used their fluxes to put stringent constraints on the physical conditions (temperature, density and column density) of the emitting gas. Simple LVG modelling implies that the emission originates in a very small (similar to 200 AU), dense (greater than or equal to 10(7) cm(-3)) and warm (similar to 100 K) region, with a column density larger than about 10(16) cm(-2). The detected H2O emission may be well accounted for by thermal emission from a collapsing envelope, and we derive constraints on the acccretion rate and central mass of NGC1333-IRAS4. We also discuss an alternative scenario in which the H2O emission arises in an extremely dense shock very close to the central object, perhaps caused by the interaction of the outflow with the innner regions of the circumstellar envelope. C1 Observ Grenoble, Astrophys Lab, F-38041 Grenoble, France. Ctr Etud Spatiale Rayonnements, CNES, F-31029 Toulouse, France. Inst Radio Astron Millimetr, F-38406 St Martin Dheres, France. SRON, NL-9700 AV Groningen, Netherlands. CALTECH, IPAC, Pasadena, CA 91125 USA. Stockholm Observ, S-13336 Saltsjobaden, Sweden. CNR, IFSI, I-00133 Rome, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ London Queen Mary & Westfield Coll, London E1 4NS, England. RP Ceccarelli, C (reprint author), Observ Grenoble, Astrophys Lab, BP 53X, F-38041 Grenoble, France. RI Molinari, Sergio/O-4095-2016 OI Molinari, Sergio/0000-0002-9826-7525 NR 19 TC 45 Z9 45 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD FEB PY 1999 VL 342 IS 2 BP L21 EP L24 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 168QH UT WOS:000078703400001 ER PT J AU Colbert, JW Malkan, MA Clegg, PE Cox, P Fischer, J Lord, SD Luhman, M Satyapal, S Smith, HA Spinoglio, L Stacey, G Unger, SJ AF Colbert, JW Malkan, MA Clegg, PE Cox, P Fischer, J Lord, SD Luhman, M Satyapal, S Smith, HA Spinoglio, L Stacey, G Unger, SJ TI ISO LWS spectroscopy of M82: A unified evolutionary model SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; galaxies : individual (M82); galaxies : ISM; galaxies : starburst; infrared : galaxies ID FAR-INFRARED SPECTROSCOPY; PHOTODISSOCIATION REGIONS; INTERSTELLAR-MEDIUM; STARBURST NUCLEUS; GALACTIC NUCLEI; STAR-FORMATION; GAS DISK; GALAXY; LINE; EMISSION AB We present the first complete far-infrared spectrum (43-197 mu m) of M82, the brightest infrared galaxy in the sky, taken with the Long Wavelength Spectrometer of the Infrared Space Observatory (ISO). We detected seven fine structure emission lines, [O I] 63 and 145 mu m, [O III] 52 and 88 mu m, [N II] 122 mu m, [N III] 57 mu m, and [C II] 158 mu m, and fitted their ratios to a combination starburst and photodissociation region (PDR) model. The best fit is obtained with H II regions with n = 250 cm(-3), an ionization parameter of 10(-3.5), and PDRs with n = 10(3.3) cm(-3) and a far-ultraviolet flux of G(0) = 10(2.8). We applied both continuous and instantaneous starburst models, with our best fit being a 3-5 Myr old instantaneous burst model with a 100 M-. cutoff. We also detected the ground-state rotational line of OH in absorption at 119.4 mu m. No excited level OH transitions are apparent, indicating that the OH is almost entirely in its ground state with a column density similar to 4 x 10(14) cm(-2). The spectral energy distribution over the long-wavelength spectrometer wavelength range is well fitted with a 48 K dust temperature and an optical depth, tau(Dust) proportional to lambda(-1). C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ London Queen Mary & Westfield Coll, Dept Phys, London E1 4NS, England. Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CNR, Ist Fis Spazio Interplanetario, I-00044 Frascati, Italy. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. RP Colbert, JW (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. OI Spinoglio, Luigi/0000-0001-8840-1551 NR 51 TC 98 Z9 98 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 1 PY 1999 VL 511 IS 2 BP 721 EP 729 DI 10.1086/306711 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176NN UT WOS:000079158100018 ER PT J AU D'Alessio, P Canto, J Hartmann, L Calvet, N Lizano, S AF D'Alessio, P Canto, J Hartmann, L Calvet, N Lizano, S TI On the thermal stability of irradiation-dominated pre-main-sequence disks SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; circumstellar matter; instabilities; stars : pre-main-sequence ID T-TAURI-STARS; SPECTRAL ENERGY-DISTRIBUTIONS; YOUNG STELLAR OBJECTS; ACCRETION DISKS; CIRCUMSTELLAR DISKS; EVOLUTION; SYSTEMS AB The dusty disks of many young stars are probably heated mostly by absorption of light from the central star. This stellar irradiation can control the vertical structure of the disk, particularly in the outer regions. Because the irradiation heating is sensitive to the disk structure-the disk vertical thickness and the tilt of the disk photosphere relative to the star-the possibility of an unstable feedback is present. To study this problem, we present calculations of the evolution of perturbations in vertically isothermal disks. We find that such disks are generally stable. In outer disk regions of T Tauri stars, linear analysis indicates that the radiative cooling time is so short that temperature perturbations will be damped faster than the disk structure can respond. Using our results for steady "alpha" viscosity disks, we estimate that this is true for distances larger than 2 AU ((M) over dot/10(-8) M. yr(-1))(7/9)(alpha/0.01)(-7/9) for typical T Tauri stars. Inside this radius, if the disk surface tilt ("flaring") is still significant, numerical finite-amplitude calculations show that temperature perturbations will travel inward as they damp. We find that disk self-shadowing has a small effect on the results because the perturbation is damped on a timescale shorter than the time in which the shadowed disk region can respond. Our results help justify steady, smooth treatments of the effects of irradiation on the disks of young stellar objects. C1 Natl Autonomous Univ Mexico, Inst Astron, Mexico City 04510, DF, Mexico. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP D'Alessio, P (reprint author), Natl Autonomous Univ Mexico, Inst Astron, Apartado Postal 70264,Cd Univ, Mexico City 04510, DF, Mexico. NR 22 TC 24 Z9 24 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 1 PY 1999 VL 511 IS 2 BP 896 EP 903 DI 10.1086/306704 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176NN UT WOS:000079158100034 ER PT J AU Gonzalez, G Wallerstein, G Saar, SH AF Gonzalez, G Wallerstein, G Saar, SH TI Parent stars of extrasolar planets. IV. 14 Herculis, HD 187123, and HD 210277 SO ASTROPHYSICAL JOURNAL LA English DT Article DE planetary systems; stars : individual (14 Herculis, HD 187123, HD 210277) ID SOLAR-TYPE STARS; STELLAR MODELS; 51-PEGASI; 47-URSAE-MAJORIS; NEIGHBORHOOD; EVOLUTION; GRIDS AB Spectroscopic analyses of 14 Her, HD 187123, and HD 210277, recently reported to harbor planets, reveal that these stars are metal rich. We find [Fe/H] = 0.50 +/- 0.05, 0.16 +/- 0.05, and 0.24 +/- 0.05 for 14 Her, HD 187123, and HD 210277, respectively. This is the first spectroscopic analysis of HD 187123; our results for 14 Her and HD 210277 are in agreement with published studies. It is shown that 14 Her and rho(1) Cnc are nearly identical in their bulk physical characteristics. This result, combined with their extreme metallicities, suggests that their physical parameters have been affected by the process that formed their planets. These two stars join a group of about half a dozen stars in the solar neighborhood with [Fe/H] greater than or equal to 0.4. It is also shown that 51 Peg and HD 187123, which have companions with similar orbital periods and masses, are nearly identical. We find v sin i approximate to 2.0 km s(-1) for HD 210277 from a high-resolution spectrum. C1 Univ Washington, Dept Astron, Seattle, WA 98195 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Gonzalez, G (reprint author), Univ Washington, Dept Astron, Box 351580, Seattle, WA 98195 USA. NR 29 TC 74 Z9 74 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 1 PY 1999 VL 511 IS 2 BP L111 EP L114 DI 10.1086/311847 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176NP UT WOS:000079158200011 ER PT J AU Gordon, SM Duric, N Kirshner, RP Goss, WM Viallefond, F AF Gordon, SM Duric, N Kirshner, RP Goss, WM Viallefond, F TI A new sample of radio-selected and optically confirmed supernova remnants in M33 SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : individual (M33); galaxies : ISM; radio continuum : ISM; supernova remnants ID EMISSION-LINE PROPERTIES; LARGE MAGELLANIC CLOUD; X-RAY-EMISSION; COSMIC-RAYS; ASTRONOMICAL DATA; CYGNUS LOOP; SPECTROPHOTOMETRY; GALAXY; CM; MORPHOLOGY AB Using radio data to identify and optical data to confirm, we have established the largest and most complete sample of extragalactic radio-bright supernova remnants (SNRs) in the nearby spiral galaxy M33. We have identified 53 radio SNRs, doubling the size of the earlier survey by Duric et al. The increased sample size provides more insight into the nature of SNRs and provides an extensive informational database about SNRs for future studies. The SNR sample was analyzed for statistical trends that relate to the evolution of their radio emission. We report no significant correlation between the radio flux densities and diameters of SNRs in our sample. The absence of a statistically meaningful Sigma-D relation is consistent with the view that environmental factors govern the radio evolution of SNRs. A new radio luminosity function for SNRs is presented. Although there appears to be a break in the function, the break is the result of selection effects and not intrinsic to the sample. A comparison of the radio luminosity function with the integrated radio continuum properties of M33 suggests that SNRs may well be the primary source of the relativistic electrons in M33. A histogram of synchrotron spectral indices of the SNRs is presented. Statistical analysis of the spectral index distribution indicates that the mean spectral index of SNRs in M33 is steeper than the mean in samples of SNRs in the Galaxy or the LMC and is consistent with a particle spectrum expected from a diffusive shock acceleration process. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Observ Paris, Meudon Sect, F-92190 Meudon, France. RP Gordon, SM (reprint author), Lawrence Berkeley Lab, Bldg 50,Room 232,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 68 TC 76 Z9 76 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD FEB PY 1999 VL 120 IS 2 BP 247 EP 264 DI 10.1086/313175 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 192RZ UT WOS:000080094000004 ER PT J AU Lopez, JV Kersanach, R Rehner, SA Knowlton, N AF Lopez, JV Kersanach, R Rehner, SA Knowlton, N TI Molecular determination of species boundaries in corals: Genetic analysis of the Montastraea annularis complex using amplified fragment length polymorphisms and a microsatellite marker SO BIOLOGICAL BULLETIN LA English DT Article ID REEF-BUILDING CORAL; REPRODUCTIVE CHARACTERISTICS; SCLERACTINIAN CORALS; POCILLOPORA-DAMICORNIS; ACROPORA CNIDARIA; GENUS ACROPORA; PATCH REEF; DNA; POPULATIONS; HYBRIDIZATION AB Analyses of DNA have not been widely used to distinguish coral sibling species. The three members of the Montastraea annularis complex represent an important test case: they are widely studied and dominate Caribbean reefs, yet their taxonomic status remains unclear. Analysis of amplified fragment length polymorphisms (AFLPs) and a microsatellite locus, using DNA from sperm, showed that Montastraea faveolata is genetically distinct. One AFLP primer yielded a diagnostic product (880 bp in M. faveolata, 920 bp in M, franksi and M. annularis) whose homology was established by DNA sequencing. A second primer revealed a 630 bp band that was fixed in M. faveolata, and rare in M.franksi and M. annularis; in this case homologies were confirmed by Southern hybridizations. A tetranucleotide microsatellite locus with several alleles exhibited strong frequency differences between M. faveolata and the other two taxa. We did not detect comparable differences between M, annularis and M. franksi with either AFLPs (12 primers screened) or the microsatellite locus. Comparisons of AFLP patterns obtained from DNA from sperm, somatic tissues, and zooxanthellae suggest that the technique routinely amplifies coral (animal) DNA. Thus analyses based on somatic tissues may be feasible, particularly after diagnostic differences have been established using sperm DNA. C1 Smithsonian Trop Res Inst, Balboa, Panama. Univ Calif San Diego, Scripps Inst Oceanog, Marine Biol Res Div 0202, La Jolla, CA 92093 USA. RP Lopez, JV (reprint author), Smithsonian Trop Res Inst, Apartado 2072, Balboa, Panama. EM Lopez@hboi.edu; nknowlton@uscd.edu RI Lopez, Jose/F-8809-2011 OI Lopez, Jose/0000-0002-1637-4125 NR 79 TC 67 Z9 69 U1 1 U2 9 PU MARINE BIOLOGICAL LABORATORY PI WOODS HOLE PA 7 MBL ST, WOODS HOLE, MA 02543 USA SN 0006-3185 J9 BIOL BULL JI Biol. Bull. PD FEB PY 1999 VL 196 IS 1 BP 80 EP 93 DI 10.2307/1543170 PG 14 WC Biology; Marine & Freshwater Biology SC Life Sciences & Biomedicine - Other Topics; Marine & Freshwater Biology GA 170YT UT WOS:000078835400010 PM 10065530 ER PT J AU Roth, TL Bush, LM Wildt, DE Weiss, RB AF Roth, TL Bush, LM Wildt, DE Weiss, RB TI Scimitar-horned oryx (Oryx dammah) spermatozoa are functionally competent in a heterologous bovine in vitro fertilization system after cryopreservation on dry ice, in a dry shipper, or over liquid nitrogen vapor SO BIOLOGY OF REPRODUCTION LA English DT Article ID ZONA-PELLUCIDA PENETRATION; FROZEN-THAWED SPERMATOZOA; CAT FELIS-BENGALENSIS; FREE HAMSTER OVA; IN-VITRO; ARTIFICIAL-INSEMINATION; SPERM CAPACITATION; HEMIZONA ASSAY; RESOURCE BANKS; LEOPARD AB A heterologous bovine in vitro fertilization (IVF) system was used to study the functional competence of scimitar-horned oryx spermatozoa after cryopreservation. Four sperm-freezing methods were compared after dilution of ejaculates from six oryx with an equine semen extender: 1) dry ice, 2) dry shipper onestep, 3) dry shipper two-step, and 4) liquid nitrogen vapor. Postthaw sperm motility, longevity, and acrosomal status were assessed and zona pellucida penetration, fertilization, and embryo cleavage were evaluated after coincubation of thawed oryx spermatozoa with in vitro-matured domestic cow oocytes. Sperm motility index (SMI) decreased (p < 0.05) over a 6-h period, but a high percentage ( greater than or equal to 65%) of spermatozoa contained intact acrosomes in all treatments. Despite differences in sperm motility among methods, oocyte penetration, fertilization, and embryo cleavage did not differ (p greater than or equal to 0.05). However, cleavage success was < 50% across all treatments. There were positive correlations (p < 0.05; r = 0.81-0.97) between sample SMI at 3 and 6 h and fertilization, penetration, and cleavage, but no correlations (p greater than or equal to 0.05) between SMI at 0 or 1 h and IVF success. This study demonstrates that compatible heterologous gamete interaction allows thorough assessment of post-thaw sperm function in an endangered antelope. Scimitar-horned oryx spermatozoa appear relatively tolerant of varied cryopreservation methods, and preserved samples exhibit adequate post-thaw function to warrant use for assisted reproduction. C1 Cincinnati Zoo & Bot Garden, Ctr Res Endangered Wildlife, Cincinnati, OH 45220 USA. Smithsonian Inst, Natl Zool Pk, Conservat & Res Ctr, Front Royal, VA 22630 USA. RP Roth, TL (reprint author), Cincinnati Zoo & Bot Garden, Ctr Res Endangered Wildlife, 3400 Vine St, Cincinnati, OH 45220 USA. EM terri.roth@cincyzoo.org NR 41 TC 51 Z9 54 U1 0 U2 4 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 USA SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD FEB PY 1999 VL 60 IS 2 BP 493 EP 498 DI 10.1095/biolreprod60.2.493 PG 6 WC Reproductive Biology SC Reproductive Biology GA 163AW UT WOS:000078380900040 PM 9916019 ER PT J AU Stiling, P Rossi, AM Hungate, B Dijkstra, P Hinkle, CR Knott, WM Drake, B AF Stiling, P Rossi, AM Hungate, B Dijkstra, P Hinkle, CR Knott, WM Drake, B TI Decreased leaf-miner abundance in elevated CO2: Reduced leaf quality and increased parasitoid attack SO ECOLOGICAL APPLICATIONS LA English DT Article DE carbon; nitrogen ratios; field experiment; herbivore-enemy interactions; increased leaf consumption; increased parasitism; plant-herbivore interactions; plant nitrogen; CO2, response to elevation in ID INSECT HERBIVORE INTERACTIONS; ATMOSPHERIC CO2; CARBON-DIOXIDE; DECIDUOUS TREES; PERFORMANCE; PLANTS; DENSITY; PHYTOCHEMISTRY; LEPIDOPTERA; POPULATION AB Most studies on the effects of elevated CO2 have focused on the effects on plant growth and ecosystem processes. Fewer studies have examined the effects of elevated CO2 on herbivory, and of these, most have examined feeding rates in laboratory conditions. Our study takes advantage of an open-top CO2 fertilization study in a Florida scrub-oak community to examine the effects of elevated CO2 on herbivore densities, herbivore feedings rates, and levels of attack of herbivores by natural enemies. Higher atmospheric CO2 concentration reduced plant foliar nitrogen concentrations, decreased abundance of leaf-mining insect herbivores, increased per capita leaf consumption by leafminers, and increased leaf miner mortality. As suggested by other authors, reduced foliar quality contributed to the increase in herbivore mortality, but only partly. The major factor increasing mortality was higher attack rate by parasitoids. Thus increasing CO2 concentrations may reduce the survivorship of insect herbivores directly, by reducing plant quality, but also indirectly, by changing herbivore feeding and eliciting greater top-down pressure from natural enemies. C1 Univ S Florida, Dept Biol, Tampa, FL 33620 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Dynamac Corp, NASA, Kennedy Space Ctr, FL 32899 USA. NASA, Kennedy Space Ctr, FL 32899 USA. RP Stiling, P (reprint author), Univ S Florida, Dept Biol, Tampa, FL 33620 USA. RI Hungate, Bruce/F-8991-2011 OI Hungate, Bruce/0000-0002-7337-1887 FU NIDCR NIH HHS [DEB 9633717] NR 35 TC 90 Z9 94 U1 8 U2 33 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD FEB PY 1999 VL 9 IS 1 BP 240 EP 244 DI 10.2307/2641182 PG 5 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 169FM UT WOS:000078736900022 PM 11543430 ER PT J AU Bartlett, R Pickering, J Gauld, I Windsor, D AF Bartlett, R Pickering, J Gauld, I Windsor, D TI Estimating global biodiversity: tropical beetles and wasps send different signals SO ECOLOGICAL ENTOMOLOGY LA English DT Article DE beta; diversity; biodiversity; parasitoids; Pimplinae ID EARTH C1 Univ Georgia, Inst Ecol, Athens, GA 30602 USA. Nat Hist Museum, London SW7 5BD, England. Smithsonian Trop Res Inst, Balboa, Panama. RP Pickering, J (reprint author), Univ Georgia, Inst Ecol, 711 Biosci Bldg, Athens, GA 30602 USA. NR 23 TC 25 Z9 30 U1 1 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0307-6946 J9 ECOL ENTOMOL JI Ecol. Entomol. PD FEB PY 1999 VL 24 IS 1 BP 118 EP 121 DI 10.1046/j.1365-2311.1999.00177.x PG 4 WC Entomology SC Entomology GA 171VJ UT WOS:000078884500015 ER PT J AU Goodfriend, GA Stanley, DJ AF Goodfriend, GA Stanley, DJ TI Rapid strand-plain accretion in the northeastern Nile Delta in the 9th century AD and the demise of the port of Pelusium SO GEOLOGY LA English DT Article ID AGE CALIBRATION; MARINE SAMPLES; HOLOCENE; EPIMERIZATION; RACEMIZATION; SHELLS; EGYPT AB An unusually large (similar to 1 km(3)) and rapid influx of Nile River sediment in the early 800s (A.D,) resulted in accretion of an extensive strand plain (6 to 15 m thick, 35 km long, and as much as 12 km wide) on the subsiding northeastern Nile Delta margin, Egypt, This event is related to blockage of the Pelusiac branch and breaking through of a new distributary to the west of present-day Port Said, probably representing initiation of the Damietta branch. The sand is of analytically identical age throughout the area and was deposited within less than similar to 60 yr, as indicated by C-14 and amino acid racemization analyses of Donax shells from a series of cores. Radiocarbon dates, in combination with historical accounts by Al-Jakubi, who found the strand plain already in existence when he visited the area in the late 800s, place this event in the early 800s. Nilometer flood records suggest that the sequence of great floods of 813, 816, and 820 may have been the triggering events. This sudden displacement of sand caused Pelusium, then the principal port and fortified city of the northeastern Nile Delta located at the mouth of the Pelusiac branch, to be cut off from both the Nile and the Mediterranean, and led to its decline and eventual abandonment by the 12th century, when the Crusaders arrived. C1 Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. Smithsonian Inst, US Natl Museum Nat Hist, Deltas Global Change Program, Washington, DC 20560 USA. RP Goodfriend, GA (reprint author), Carnegie Inst Washington, Geophys Lab, 5251 Broad Branch Rd NW, Washington, DC 20015 USA. NR 24 TC 17 Z9 17 U1 0 U2 2 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD FEB PY 1999 VL 27 IS 2 BP 147 EP 150 DI 10.1130/0091-7613(1999)027<0147:RSPAIT>2.3.CO;2 PG 4 WC Geology SC Geology GA 167DR UT WOS:000078617800013 ER PT J AU Reid, JW AF Reid, JW TI New records of Bryocyclops from the continental USA, Puerto Rico, and Brazil (Copepoda : Cyclopoida : Cyclopidae) SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article AB Collections from Brazil, Puerto Rico, and the U.S.A. yielded new records of 3 species of Bryocyclops. Both sexes of Bryocyclops muscicola are described from a probably introduced population found in a plant nursery in Florida, U.S.A., and compared to material of B. muscicola from Java. This is the first record of the genus in North America. The known distribution of Bryocyclops campaneri in Brazil is considerably expanded, and new information provided on its morphology. Bryocyclops caroli, previously known only from Brazil, is recorded for the first time from Puerto Rico. C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Invertebrate Zool, MRC 163, Washington, DC 20560 USA. RP Reid, JW (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Dept Invertebrate Zool, MRC 163, Washington, DC 20560 USA. NR 36 TC 16 Z9 17 U1 0 U2 1 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 USA SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD FEB PY 1999 VL 19 IS 1 BP 84 EP 92 DI 10.2307/1549550 PG 9 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 164BB UT WOS:000078441100011 ER PT J AU Li, X Habbal, SR Hollweg, JV Esser, R AF Li, X Habbal, SR Hollweg, JV Esser, R TI Heating and cooling of protons by turbulence-driven ion cyclotron waves in the fast solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID AMPLITUDE ALFVEN WAVES; CORONAL HOLES; VELOCITY DISTRIBUTIONS; TRANSITION REGION; RADIAL EVOLUTION; 2-FLUID MODEL; HEAVY-IONS; ACCELERATION; TEMPERATURE; RESONANCE AB The effects of parallel propagating nondispersive ion cyclotron waves on the solar wind plasma are investigated in an attempt to reproduce the observed proton temperature anisotropy, namely, T-p perpendicular to >> T-p parallel to in the inner corona and T-p perpendicular to < T-p parallel to at 1 AU. Low-frequency Alfven waves are assumed to carry most of the energy needed to accelerate and heat the fast solar wind. The model calculations presented here assume that nonlinear cascade processes, at the Kolmogorov and Kraichnan dissipation rates, transport energy from low-frequency Alfven waves to the ion cyclotron resonant range. The energy is then picked up by the plasma through the resonant cyclotron interaction. While the resonant interaction determines how the heat is distributed between the parallel and perpendicular degrees of freedom, the level of turbulence determines the net dissipation. Ion cyclotron waves are found to produce a significant temperature anisotropy starting in the inner corona, and to limit the growth of the temperature anisotropy in interplanetary space. In addition, this mechanism heats or cools protons in the direction parallel to the magnetic field. While cooling in the parallel direction is dominant, heating in the parallel direction occurs when T-p perpendicular to >> T-p parallel to. The waves provide the mechanism for the extraction of energy from the parallel direction to feed into the perpendicular direction. In our models, both Kolmogorov and Kraichnan dissipation rates yield T-p perpendicular to >> T-p parallel to in the corona, in agreement with inferences from recent ultraviolet coronal measurements, and predict temperatures at 1 AU which match in situ observations. The models also reproduce the inferred rapid acceleration of the fast solar wind in the inner corona and flow speeds and particle fluxes measured at 1 AU. Since this mechanism does not provide direct energy to the electrons, and the electron-proton coupling is not sufficient to heat the electrons to temperatures at or above 10(6) K, this model yields electron temperatures which are much cooler than those currently inferred fram observations. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM xli@cfa.harvard.edu; shabbal@cfa.harvard.edu; joe.hollweg@unh.edu; resser@cfa.harvard.edu NR 59 TC 110 Z9 111 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1999 VL 104 IS A2 BP 2521 EP 2535 DI 10.1029/1998JA900126 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 170TX UT WOS:000078823900019 ER PT J AU Breman, JG Johnson, KM van der Groen, G Robbins, CB Szczeniowski, MV Ruti, K Webb, PA Meier, F Heymann, DL AF Breman, JG Johnson, KM van der Groen, G Robbins, CB Szczeniowski, MV Ruti, K Webb, PA Meier, F Heymann, DL CA Ebola Virus Study Teams TI A search for Ebola virus in animals in the Democratic Republic of the Congo and Cameroon: Ecologic, virologic, and serologic surveys, 1979-1980 SO JOURNAL OF INFECTIOUS DISEASES LA English DT Article ID MONKEYPOX VIRUS; IDENTIFICATION; RNA AB More than 30 years after the first outbreak of Marburg virus disease in Germany and Yugoslavia and 20 years after Ebola hemorrhagic fever first occurred in central Africa, the natural history of filoviruses remains unknown. In 1979 and 1980, animals in the Democratic Republic of the Congo and Cameroon were collected during the dry season near the site of the 1976 Ebola hemorrhagic fever epidemic, The study objectives were to identify local animals and search for evidence of Ebola virus in their tissues. A total of 1664 animals representing 117 species was collected, including >400 bats and 500 rodents, Vero and CV-1 cells and IFA and RIA were used for virus and antibody detection, respectively, No evidence of Ebola virus infection was found. This study was limited in time and animal collections and excluded insects and plants. Long-term, prospective, multidisciplinary comparative studies will yield more information than will repeat short forays on the ecology of filoviruses. C1 WHO, Smallpox Eradicat Unit, CH-1211 Geneva, Switzerland. Museum Nat Hist, Geneva, Switzerland. Ctr Dis Control & Prevent, Special Viral Pathogens Branch, Natl Ctr Infect Dis, Atlanta, GA USA. Inst Trop Med, Dept Microbiol, B-2000 Antwerp, Belgium. Natl Museum Nat Hist, Smithsonian Inst, Div Mammals, Washington, DC 20560 USA. WHO, Kinshasa, Zaire. Minist Publ Hlth, Programme Elargi Vaccinat, Kinshasa, Zaire. Org Lutte Endemies Afrique Cent, Yaounde, Cameroon. Carnegie Museum Nat Hist, Pittsburgh, PA USA. SW Missouri State Univ, Springfield, MO 65802 USA. Catholic Mission Diocese Doume, Mouloundou, Cameroon. RP Breman, JG (reprint author), NIH, Fogarty Inst Ctr, Bldg 31,Room B2C39,31 Ctr Dr,MSC 2220, Bethesda, MD 20892 USA. EM jbreman@nih.gov NR 30 TC 48 Z9 52 U1 5 U2 29 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1899 EI 1537-6613 J9 J INFECT DIS JI J. Infect. Dis. PD FEB PY 1999 VL 179 SU 1 BP S139 EP S147 PG 9 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA 163HQ UT WOS:000078400300024 PM 9988177 ER PT J AU Korine, C Arad, Z AF Korine, C Arad, Z TI Changes in milk composition of the Egyptian fruit bat, Rousettus aegyptiacus (Pteropodidae), during lactation SO JOURNAL OF MAMMALOGY LA English DT Article DE Rousettus aegyptiacus; fruit bat; lactation; milk composition ID NITROGEN; CHIROPTERA; MINERALS AB Composition of milk of the free-ranging Egyptian fruit-bat (Rousettus aegypriacus) was studied from early to peak lactation. Carbohydrates were the main component during early lactation and fats were the main component in milk from mid- to peak lactation. Dry-matter and energy content of the milk increased during mid-lactation and stabilized at peak lactation. Increases were a consequence of increased fat content, but carbohydrate and protein contents remained relatively stable. We conclude that the milk composition of R. aegyptiacus is related to diet and frequent suckling by young. We suggest that the inability of R. aegyptiacus to produce concentrated milk of high fat and energy contents and a low protein content is compensated for by prolonged lactation. C1 Technion Israel Inst Technol, Dept Biol, IL-32000 Haifa, Israel. RP Korine, C (reprint author), Smithsonian Trop Res Inst, Balboa, Panama. RI Korine, Carmi/F-4116-2012 NR 22 TC 8 Z9 9 U1 1 U2 7 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-2372 EI 1545-1542 J9 J MAMMAL JI J. Mammal. PD FEB PY 1999 VL 80 IS 1 BP 53 EP 59 DI 10.2307/1383207 PG 7 WC Zoology SC Zoology GA 169GH UT WOS:000078738800006 ER PT J AU Thiel, M AF Thiel, M TI Host-use and population demographics of the ascidian-dwelling amphipod Leucothoe spinicarpa: indication for extended parental care and advanced social behaviour SO JOURNAL OF NATURAL HISTORY LA English DT Article DE amphipoda; ascidians; association; host-specialization; parental care ID SWEDISH WEST-COAST; REPRODUCTIVE PATTERNS; PARACERCEIS-SCULPTA; MALE MORPHS; CRUSTACEA; DYNAMICS; BIOLOGY; SPONGES; ISOPODA; SHRIMP AB Leucothoe spinicarpa (Abildgaard, 1789) is an endobiotic amphipod, commonly found in sponges, bivalves and ascidians. I examined the occurrence and population demographics of L. spinicarpa in different species of solitary and stolonal ascidians from two lagoonal embayments on the Florida Atlantic Coast. Between 77 and 95% of the solitary ascidians Ascidia nigra (Savigny, 1816), Microcosmos exasperatus Heller, 1878 and Styela plicata (Leseuer, 1825) were hosts to L. spinicarpa. The high rate of occupancy in large solitary ascidians by L spinicarpa in September 1997 suggests that competition for these microhabitats can occur. The average number of amphipods ascidian(-1) varied between 1.89 +/- 0.48 s.e. in S. plicata and 5.60 +/- 1.24 s.e. in M. exasperatus both from the Indian River Lagoon. The maximum number of amphipods ascidian(-1) was 30 in A. nigra from Lake Worth. Prevalence of L. spinicarpa in stolonal ascidians is substantially lower than in solitary ones. Many zooids contained no amphipods, but at one site, 9.4% of all zooids of Clavelina oblonga Herdman, 1880 were host to L. spinicarpa. At this location, usually single amphipods were found in a zooid, however, one zooid of C. oblonga contained three amphipods and another zooid contained four. The size range of L. spinicarpa found in solitary ascidians differs considerably from that of amphipods collected in stolonal species. All sizes of amphipods occurred in solitary ascidians, while individuals found in stolonal ascidians were usually <5 mm and immature. Some solitary ascidians contained an adult male and female pair and a dutch of similar-sized juveniles. These observations show that juveniles remain in their parents' dwelling after hatching from the female's brood pouch. It is concluded that after leaving the parental dwelling, many subadult L. spinicarpa seek shelter in the zooids of stolonal ascidians before they relocate to larger, solitary ascidians when reaching maturity. The demographics of amphipod groups suggest that some offspring reach maturity in their parents' dwelling and inherit the parental ascidian after the death of their parents. Thus, in this ascidian-dwelling amphipod extended parental care in a stable microhabitat may have led to the evolution of advanced social behaviour. C1 Smithsonian Marine Stn, Ft Pierce, FL 34946 USA. RP Thiel, M (reprint author), Univ Catolica de Norte, Fac Giencias Mar, Larrondo 1281,Campus Guayacan, Coquimbo, Chile. NR 48 TC 25 Z9 27 U1 1 U2 4 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0022-2933 EI 1464-5262 J9 J NAT HIST JI J. Nat. Hist. PD FEB PY 1999 VL 33 IS 2 BP 193 EP 206 DI 10.1080/002229399300371 PG 14 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 167JH UT WOS:000078628400003 ER PT J AU Clifton, KE Clifton, LM AF Clifton, KE Clifton, LM TI The phenology of sexual reproduction by green algae (Bryopsidales) on Caribbean coral reefs SO JOURNAL OF PHYCOLOGY LA English DT Article DE Bryopsidales; Caulerpa; coral reefs; gamete release; Halimeda; marine algae; Penicillus; phototaxis; Rhipocephalus; reproductive ecology; sexual reproduction; Udotea ID MACROALGA CAULERPA-CUPRESSOIDES; GREAT-BARRIER-REEF; FERTILIZATION SUCCESS; SPAWNING INVERTEBRATE; MARINE-INVERTEBRATES; PENICILLUS-CAPITATUS; SPERM LIMITATION; EGG SIZE; CHLOROPHYTA; HALIMEDA AB Recent field observations of highly organized, species- and sex-specific patterns of synchronous gamete release by tropical green algae (Bryopsidales) invite a variety of future studies into the ecology and life histories of an important component of tropical reef communities. This paper details sexual reproduction by 22 algal species within five common genera (Caulerpa, Halimeda, Penicillus, Rhipocephalus, and Udotea), including field observations on the spatial occurrence, timing, and color changes associated with fertility, data on gamete size and behavior, and descriptions of coincident changes in local species abundances. Ecologically ephemeral episodes of sexual reproduction involved macroscopic changes that reliably indicated developmental state and sexual identity. The time from onset of fertility to gamete release was 36 h (Halimeda), 48 h (Caulerpa, Penicillus, and Rhipocephalus), or 96 h (Udotea). All species produced flagellated, negatively buoyant, anisogamous gametes, Microgametes of all species were similar in size; however, considerable species-specific differences were seen in the size of macrogametes. In Caulerpa, Halimeda, and Udotea flabellum (Ellis and Solander) Lamouroux, the volumetric ratio of macrogametes to microgametes ranged from 2:1 to 45: 1, whereas more extreme levels of anisogamy (10(4):1) were observed for Penicillus spp., Rhipocephalus phoenix (Ellis and Solander) Kuetzing, and other Udotea spp, The macrogametes of Caulerpa and Halimeda showed strong positive phototaxis. Although only a subset (generally about 5%) of the thalli representing each species released gametes on a given morning, most species underwent bouts of sexual reproduction on numerous occasions during the seasonal peak of reproductive activity (March-May), As might be expected for holocarpic species, dramatic declines in local algal abundance coincided with these periods. The density of sand-dwelling genera such as Penicillus fell by 80-90% during this 3-month period in 1997. Similar declines in the cover of sprawling species such as Caulerpa racemosa ((Forsskal) J. Agardh) exposed large (35-50 m(2)) sections of previously overgrown reef substrate. C1 Smithsonian Trop Res Inst, Balboa, Panama. RP Lewis & Clark Coll, Dept Biol, 0615 SW Palatine Hill Rd, Portland, OR 97219 USA. EM clifton@lclark.edu NR 68 TC 70 Z9 73 U1 1 U2 20 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0022-3646 EI 1529-8817 J9 J PHYCOL JI J. Phycol. PD FEB PY 1999 VL 35 IS 1 BP 24 EP 34 DI 10.1046/j.1529-8817.1999.3510024.x PG 11 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 172LU UT WOS:000078926400005 ER PT J AU Correll, DL Jordan, TE Weller, DE AF Correll, DL Jordan, TE Weller, DE TI Effects of interannual variation of precipitation on stream discharge from Rhode River subwatersheds SO JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION LA English DT Article DE surface water hydrology; precipitation; land use; long-term; forest; cropland; coastal plain ID NUTRIENT BUDGETS; ESTUARY; NITRATE; ZONE AB The purpose of this study was to determine the relationships between precipitation at the seasonal and annual scale and water discharge per surface area for seven contiguous first- and second-order tributaries of the Rhode River, a small tidal tributary to Chesapeake Bay, Maryland, USA. The goal was to quantify the effects of a wide range of precipitation, representative of interannual variations in weather in this region. The discharges measured included both overland storm flows and groundwater, since the aquifers were perched on a clay aquiclude. Precipitation varied from 824 to 1684 mm/yr and area-weighted Rhode River watershed discharge varied from 130 to 669 mm/yr with an average of 332 mm/yr or 29.1 percent of average precipitation. Average annual discharges from three first-order watersheds were significantly lower per surface area and varied from 16.0 to 21.9 percent of precipitation. Winter season precipitation varied from 125 to 541 mm. Area-weighted Rhode River winter discharge varied from 26.3 to 230 mm with an average of 115 mm or 43.9 percent of average precipitation. Spring season precipitation varied from 124 to 510 mm and watershed discharge varied from 40.0 to 321 mm with an average of 138 mm or 46.9 percent of average precipitation. In the summer and fall seasons, watershed discharge averaged 40.6 and 40.9 mm or 13.5 and 14.3 percent of average precipitation, respectively Except in winter, the proportion of precipitation discharged in the streams increased rapidly with increasing volume of precipitation. Stream order showed a higher correlation with volume of discharge than vegetative cover on the watershed. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Correll, DL (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. OI Weller, Donald/0000-0002-7629-5437 NR 18 TC 10 Z9 10 U1 0 U2 5 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 20170-5531 USA SN 1093-474X J9 J AM WATER RESOUR AS JI J. Am. Water Resour. Assoc. PD FEB PY 1999 VL 35 IS 1 BP 73 EP 82 DI 10.1111/j.1752-1688.1999.tb05453.x PG 10 WC Engineering, Environmental; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 179TM UT WOS:000079345200006 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI Building the great cathedrals. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Libs, Arlington, VA USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Libs, Arlington, VA USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD FEB 1 PY 1999 VL 124 IS 2 BP 84 EP 85 PG 2 WC Information Science & Library Science SC Information Science & Library Science GA 160KC UT WOS:000078228500066 ER PT J AU Riley, SM AF Riley, SM TI Rescue. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Libs, Washington, DC 20560 USA. RP Riley, SM (reprint author), Smithsonian Inst Libs, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD FEB 1 PY 1999 VL 124 IS 2 BP 122 EP 123 PG 2 WC Information Science & Library Science SC Information Science & Library Science GA 160KC UT WOS:000078228500279 ER EF