Multicenter study of the impact of community-onset Clostridium difficile infection on surveillance for C. difficile infection

OBJECTIVE: To evaluate the influence of community-onset/healthcare facility-associated cases on Clostridium difficile infection (CDI) incidence and outbreak detection. DESIGN: Retrospective cohort. SETTING: Five acute-care healthcare facilities in the United States. METHODS: Positive stool C. difficile toxin assays from July 2000 through June 2006 and healthcare facility exposure information were collected. CDI cases were classified as hospital-onset (HO) if they were diagnosed > 48 hours after admission or community-onset/healthcare facility-associated if they were diagnosed ≤ 48 hours from admission and had recently been discharged from the healthcare facility. Four surveillance definitions were compared: HO cases only and HO plus community-onset/healthcare facility-associated cases diagnosed within 30 (HCFA-30), 60 (HCFA-60) and 90 (HCFA-90) days after discharge from the study hospital. Monthly CDI rates were compared. Control charts were used to identify potential CDI outbreaks. RESULTS: The HCFA-30 rate was significantly higher than the HO rate at two healthcare facilities (p<0.01). The HCFA-30 rate was not significantly different from the HCFA-60 or HCFA-90 rates at any healthcare facility. The correlations between each healthcare facility’s monthly rates of HO and HCFA-30 CDI were almost perfect (range, 0.94–0.99, p<0.001). Overall, 12 time points had a CDI rate >3 SD above the mean, including 11 by the HO definition and 9 by the HCFA-30 definition, with discordant results at 4 time points (κ = 0.794, p<0.001). CONCLUSIONS: Tracking community-onset/healthcare facility-associated cases in addition to HO cases captures significantly more CDI cases but surveillance of HO CDI alone is sufficient to detect an outbreak

Firearms on College Campuses: Research Evidence nad Policy Implications

This report reviews the evidence surrounding the relationship between civilian gun carrying and violent crime and mass shootings and factors that are unique to public safety on college campuses. Policies removing restrictions on civilian gun carrying are based on claims or assumptions about civilian gun use, the impact of state Right-to-Carry (RTC) laws, and the nature of mass shootings that are not supported by or are contrary to the best available research. The incidence of civilian self-defensive gun use (SDGU) is difficult to discern as available data are based on self-report, and distinguishing aggressor from victim in interpersonal altercations can be highly subjective. Nonetheless, data from the National Crime Victimization Survey indicate that SDGU is relatively rare (about 102,000 self-reported incidents per year affecting 0.9% of all violent crime victimizations) and is no more effective in reducing victims' risk of injury than other victim responses to attempted violent crimes. Research led by John Lott, author of More Guns, Less Crime, suggesting that RTC laws prevent violent crime has important flaws that biased his findings. The most recent and rigorous research on RTC laws that corrects for these flaws consistently finds that RTC laws are associated with more violent crime. These findings may seem counterintuitive because concealed-carry permit holders have, as a group, low rates of criminal offending and must pass a background check to ensure that they do not have any condition, such as a felony conviction, that prohibits firearm ownership. But, in states with low standards for legal gun ownership, legal gun owners account for the majority of persons incarcerated for committing violent crimes with firearms

An Optically Dark GRB Observed by HETE-2: GRB 051022

GRB 051022 was detected at 13:07:58 on 22 October 2005 by HETE-2. The location of GRB 051022 was determined immediately by the flight localization system. This burst contains multiple pulses and has a rather long duration of about 190 seconds. The detections of candidate X-ray and radio afterglows were reported, whereas no optical afterglow was found. The optical spectroscopic observations of the host galaxy revealed the redshift z = 0.8. Using the data derived by HETE-2 observation of the prompt emission, we found the absorption N_H = 8.8 -2.9/+3.1 x 10^22 cm^-2 and the visual extinction A_V = 49 -16/+17 mag in the host galaxy. If this is the case, no detection of any optical transient would be quite reasonable. The absorption derived by the Swift XRT observations of the afterglow is fully consistent with those obtained from the early HETE-2 observation of the prompt emission. Our analysis implies an interpretation that the absorbing medium could be outside external shock at R ~ 10^16 cm, which may be a dusty molecular cloud.Comment: 6 pages, 2 figures, accepted for publication in PASJ lette

LSST Science Book, Version 2.0

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo