135 research outputs found

    A search for the most massive galaxies: Double Trouble?

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    We describe the results of a search for galaxies with large (> 350 km/s) velocity dispersions. The largest systems we have found appear to be the extremes of the early-type galaxy population: compared to other galaxies with similar luminosities, they have the largest velocity dispersions and the smallest sizes. However, they are not distant outliers from the Fundamental Plane and mass-to-light scaling relations defined by the bulk of the early-type galaxy population. They may host the most massive black holes in the Universe, and their abundance and properties can be used to constrain galaxy formation models. Clear outliers from the scaling relations tend to be objects in superposition (angular separations smaller than 1 arcsec), evidence for which comes sometimes from the spectra, sometimes from the images, and sometimes from both. The statistical properties of the superposed pairs, e.g., the distribution of pair separations and velocity dispersions, can be used to provide useful information about the expected distribution of image multiplicities, separations and flux ratios due to gravitational lensing by multiple lenses, and may also constrain models of their interaction rates.Comment: 20 pages, 8 figures. Accepted by AJ. The full set of figures in Appendix B is available at http://www.physics.upenn.edu/~bernardm/PAPERS/BIGEtypes/bernardi.FIG-B.ps.gz Figure 8 did not show the set of galaxies described in the text of the appendix. This has now been correcte

    Survival enhancing indications for coronary artery bypass graft surgery in California

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    <p>Abstract</p> <p>Background</p> <p>Coronary artery bypass graft (CABG) surgery is performed because of anticipated survival benefit, improvement in quality of life, or both. We performed this study to explore variations in clinical indications for CABG surgery among California hospitals and surgeons.</p> <p>Methods</p> <p>Using California CABG Outcomes Reporting Program data, we classified all isolated CABG cases in 2003–2004 as having "probable survival enhancing indications (SEIs)", "possible SEIs" or "non-SEIs." Patient and hospital characteristics associated with SEIs were examined.</p> <p>Results</p> <p>While 82.9% of CABG were performed for probable SEIs, the range extended from 68% to 96% among hospitals and 51% to 100% among surgeons. SEI rates were higher among patients aged ≥ 65 compared with those aged 18–64 (Adjusted Odds Ratio [AOR] > 1.29 for age groups 65–69, 70–74 and ≥ 75; all p < 0.001), among Asians and Native Americans compared with Caucasians (AOR 1.22 and 1.15, p < 0.001); and among patients with hypertension, peripheral vascular disease, diabetes, cerebrovascular disease and congestive heart failure compared to patients without these conditions (AOR > 1.09, all p < 0.001). Variations in indications for surgery were more strongly related to patient mix than to surgeon or hospital effects (intraclass correlation [ICC] = 0.04 for hospital; ICC = 0.01 for surgeon).</p> <p>Conclusion</p> <p>California hospitals and surgeons vary in their distribution of indications for CABG surgery. Further research is required to identify the roles of market factors, referral patterns, patient preferences, and local clinical culture in producing the observed variations.</p

    Comment Letters to proposed statement on standards for attestation engagements : Management\u27s discussion and analysis

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    https://egrove.olemiss.edu/aicpa_sas/1108/thumbnail.jp

    Comment letters to the National Commission on Commission on Fraudulent Financial Reporting, 1987 (Treadway Commission) Vol. 1

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    https://egrove.olemiss.edu/aicpa_sop/1661/thumbnail.jp
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