8,051 research outputs found
Predicting outcome following colorectal cancer surgery using Colorectal Biochemical and Haematological Outcome Model (Colorectal BHOM)
EERS (Economic Evaluation of a Residue System) : a model for analyzing the economics of installing a steam kiln and wood-fired boiler at a West Virginia sawmill
Exploring Halo Substructure with Giant Stars: The Dynamics and Metallicity of the Dwarf Spheroidal in Bootes
We report the results of a spectroscopic study of the Bootes (Boo) dwarf
spheroidal (dSph) galaxy carried out with the WIYN telescope and the Hydra
multifiber spectrograph. Radial velocities have been measured for 58 Boo
candidate stars selected to have magnitudes and colors consistent with its red
and asymptotic giant branches. Within the 13' half-light radius, seven members
of Boo yield a systemic velocity of V_r=95.6+-3.4 km/s and a velocity
dispersion of 6.6+-2.3 km/s. This implies a mass on the order of 1 x 10^7
M_sun, similar to the inferred masses of other Galactic dSphs. Adopting a total
Boo luminosity of L=1.8 x 10^4 L_sun to 8.6 x 10^4 L_sun implies M/L ~ 610 to
130, making Boo, the most distorted known Milky Way dwarf galaxy, potentially
also the darkest. From the spectra of Boo member stars we estimate its
metallicity to be [Fe/H] ~ -2.5, which would make it the most metal poor dSph
known to date.Comment: Accepted for publication in ApJ Letter
Rapid Oscillations in Cataclysmic Variables. XV. HT Camelopardalis (= RX J0757.0+6306)
We present photometry and spectroscopy of HT Camelopardalis, a recently
discovered X-ray-bright cataclysmic variable. The spectrum shows bright lines
of H, He I, and He II, all moving with a period of 0.059712(1) d, which we
interpret as the orbital period. The star's brightness varies with a strict
period of 515.0592(2) s, and a mean full amplitude of 0.11 mag. These
properties qualify it as a /bona fide/ DQ Herculis star (intermediate polar) --
in which the magnetism of the rapidly rotating white dwarf channels accretion
flow to the surface. Normally at V=17.8, the star shows rare and very brief
outbursts to V=12-13. We observed one in December 2001, and found that the 515
s pulse amplitude had increased by a factor of ~100 (in flux units). A
transient orbital signal may also have appeared.Comment: PDF, 19 pages, 3 tables, 6 figures; accepted, in press, to appear
June 2002, PASP; more info at http://cba.phys.columbia.edu
Measuring Fundamental Galactic Parameters with Stellar Tidal Streams and SIM PlanetQuest
Extended halo tidal streams from disrupting Milky Way satellites offer new
opportunities for gauging fundamental Galactic parameters without challenging
observations of the Galactic center. In the roughly spherical Galactic
potential tidal debris from a satellite system is largely confined to a single
plane containing the Galactic center, so accurate distances to stars in the
tidal stream can be used to gauge the Galactic center distance, R_0, given
reasonable projection of the stream orbital pole on the X_GC axis.
Alternatively, a tidal stream with orbital pole near the Y_GC axis, like the
Sagittarius stream, can be used to derive the speed of the Local Standard of
Rest (\Theta_LSR). Modest improvements in current astrometric catalogues might
allow this measurement to be made, but NASA's Space Interferometry Mission (SIM
PlanetQuest) can definitively obtain both R_0 and \Theta_LSR using tidal
streams.Comment: 8 pages, 4 figures, accepted for publication in ApJ Letters (minor
text revisions). Version with high resolution figures available at
http://www.astro.caltech.edu/~drlaw/Papers/GalaxyParameters.pd
Streptococcus pneumoniae as a Cause of Salpingitis
Background: A case of pneumococcal septicemia associated with
laparoscopically documented acute salpingitis is reported
Multiple Fault Isolation in Redundant Systems
Fault diagnosis in large-scale systems that are products of modern technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption
Names are key to the big new biology
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Trends in Ecology & Evolution 25 (2010): 686-691, doi:10.1016/j.tree.2010.09.004.Those who seek answers to big, broad questions about biology, especially questions
emphasizing the organism (taxonomy, evolution, ecology), will soon benefit from an emerging
names-based infrastructure. It will draw on the almost universal association of organism names
with biological information to index and interconnect information distributed across the Internet.
The result will be a virtual data commons, expanding as further data are shared, allowing biology to
become more of a âbig scienceâ. Informatics devices will exploit this âbig new biologyâ,
revitalizing comparative biology with a broad perspective to reveal previously inaccessible trends
and discontinuities, so helping us to reveal unfamiliar biological truths. Here, we review the first
components of this freely available, participatory, and semantic Global Names Architecture.DJP thanks the NSF for support through the Data Conservancy project and the Alfred P. Sloan and
John D. and Catherine T. MacArthur foundations for their support
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