94 research outputs found
Biochemical Mediators Involved in Cartilage Degradation and the Induction of Pain in Osteoarthritis
Declaration of Michael J. Keegan, In re Chrysler LLC, 405 B.R. 84 (No. 09-50002), Docket # 312
A Catalog of Compact Groups of Galaxies in the SDSS Commissioning Data
Compact groups (CGs) of galaxies -- relatively poor groups of galaxies in
which the typical separations between members is of the order of a galaxy
diameter -- offer an exceptional laboratory for the study of dense galaxian
environments with short (<1Gyr) dynamical time-scales. In this paper, we
present an objectively defined catalog of CGs in 153 sq deg of the Sloan
Digital Sky Survey Early Data Release (SDSS EDR). To identify CGs, we applied a
modified version of Hickson's (1982) criteria aimed at finding the highest
density CGs and thus reducing the number of chance alignments. Our catalog
contains 175 CGs down to a limiting galaxy magnitude of r* = 21. The resulting
catalog has a median depth of approximately z = 0.13, substantially deeper than
previous CG catalogs. Since the SDSS will eventually image up to one quarter of
the celestial sphere, we expect our final catalog, based upon the completed
SDSS, will contain on the order of 5,000 - 10,000 CGs. This catalog will be
useful for conducting studies of the general characteristics of CGs, their
environments, and their component galaxies.Comment: 61 pages, 15 figures (Figs. 13, 14, 15 are jpegs). Atlas of compact
groups (Fig. 16) is available at http://home.fnal.gov/~sallam/LeeCG/ .
Accepted for publication by the Astronomical Journa
Synthesis of Nitrogenated Heterocycles by Asymmetric Transfer Hydrogenation of N-(tert-Butylsulfinyl)haloimines
Highly optically enriched, protected, nitrogenated heterocycles with different ring sizes have been synthesized by a very efficient methodology consisting of the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)haloimines followed by treatment with a base to promote an intramolecular nucleophilic substitution process. N-Protected aziridines, pyrrolidines, piperidines, and azepanes bearing aromatic, heteroaromatic, and aliphatic substituents have been obtained in very high yields and diastereomeric ratios up to >99:1. The free heterocycles can be easily obtained by a simple and mild desulfinylation procedure. Both enantiomers of the free heterocycles can be prepared with the same good results by changing the absolute configuration of the sulfur atom of the sulfinyl group.This work was generously supported by the Spanish Ministerio de Ciencia e Innovación (MICINN; grant no. CONSOLIDER INGENIO 2010, CSD2007-00006, CTQ2007-65218 and CTQ2011-24151) and the Generalitat Valenciana (PROMETEO/2009/039 and FEDER). O.P. thanks the Spanish Ministerio de Educación for a predoctoral fellowship (grant no. AP-2008-00989)
The Sloan Digital Sky Survey: Technical Summary
The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed
investigations of the distribution of luminous and non- luminous matter in the
Universe: a photometrically and astrometrically calibrated digital imaging
survey of pi steradians above about Galactic latitude 30 degrees in five broad
optical bands to a depth of g' about 23 magnitudes, and a spectroscopic survey
of the approximately one million brightest galaxies and 10^5 brightest quasars
found in the photometric object catalog produced by the imaging survey. This
paper summarizes the observational parameters and data products of the SDSS,
and serves as an introduction to extensive technical on-line documentation.Comment: 9 pages, 7 figures, AAS Latex. To appear in AJ, Sept 200
Prevalence of Plasmodium falciparum anti-malarial resistance-associated polymorphisms in pfcrt, pfmdr1 and pfnhe1 in Muheza, Tanzania, prior to introduction of artemisinin combination therapy
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