3,204 research outputs found

    The Optical - Infrared Colors of CORALS QSOs: Searching for Dust Reddening Associated With High Redshift Damped Lyman Alpha Systems

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    The presence of dust in quasar absorbers, such as damped Lyman alpha (DLA) systems, may cause the background QSO to appear reddened. We investigate the extent of this potential reddening by comparing the optical-to-infrared (IR) colors of QSOs with and without intervening absorbers. Our QSO sample is based on the Complete Optical and Radio Absorption Line System (CORALS) survey of Ellison et al (2001). We have obtained near-simultaneous B and K band magnitudes for subset of the CORALS sample and supplemented our observations with further measurements published in the literature. To account for redshift-related color changes, the B-K colors are normalized using the Sloan Digital Sky Survey (SDSS) QSO composite. The mean normalized B-K color of the DLA sub-sample is +0.12, whereas the mean for the no-DLA sample is -0.10; both distributions have RMS scatters ~0.5. Neither a student's T-test nor a KS test indicate that there is any significant difference between the two color distributions. Based on simulations which redden the colors of QSOs with intervening DLAs, we determine a reddening limit which corresponds to E(B-V) < 0.04 (SMC-like extinction) at 99% confidence (3 sigma), assuming that E(B-V) is the same for all DLAs. Finally, we do not find any general correlation between absorber properties (such as [Fe/Zn] or neutral hydrogen column density) and B-K color. One of these two QSOs shows evidence for strong associated absorption from X-ray observations, an alternative explanation for its very red color. We conclude that the presence of intervening galaxies causes a minimal reddening of the background QSO.Comment: Accepted for publication in A

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    No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58017/1/23350_ftp.pd

    Risk of myocardial infarction and stroke after acute infection or vaccination.

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    BACKGROUND: There is evidence that chronic inflammation may promote atherosclerotic disease. We tested the hypothesis that acute infection and vaccination increase the short-term risk of vascular events. METHODS: We undertook within-person comparisons, using the case-series method, to study the risks of myocardial infarction and stroke after common vaccinations and naturally occurring infections. The study was based on the United Kingdom General Practice Research Database, which contains computerized medical records of more than 5 million patients. RESULTS: A total of 20,486 persons with a first myocardial infarction and 19,063 persons with a first stroke who received influenza vaccine were included in the analysis. There was no increase in the risk of myocardial infarction or stroke in the period after influenza, tetanus, or pneumococcal vaccination. However, the risks of both events were substantially higher after a diagnosis of systemic respiratory tract infection and were highest during the first three days (incidence ratio for myocardial infarction, 4.95; 95 percent confidence interval, 4.43 to 5.53; incidence ratio for stroke, 3.19; 95 percent confidence interval, 2.81 to 3.62). The risks then gradually fell during the following weeks. The risks were raised significantly but to a lesser degree after a diagnosis of urinary tract infection. The findings for recurrent myocardial infarctions and stroke were similar to those for first events. CONCLUSIONS: Our findings provide support for the concept that acute infections are associated with a transient increase in the risk of vascular events. By contrast, influenza, tetanus, and pneumococcal vaccinations do not produce a detectable increase in the risk of vascular events

    Implicit and Explicit Values as a Predictor of Ethical Decision-Making and Ethical Behavior

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    The present study uses measures of implicit and explicit values to predict moral behaviors. Implicit value measures based on a word-fragment completion tasks were developed in this study to assess implicit values. Because values and moral processes are believed to operate at both explicit and implicit levels, it was hypothesized that both implicit and explicit values would predict moral behaviors. Results from a laboratory study show that both implicit and explicit values predicted actual moral behavior, consistent with dual process theories of morality. Chronic collective identity moderated the relation of both implicit and explicit values to ethical behavior. Theoretical and practical implications for the use of both explicit and implicit value measures in research and applied settings are discussed

    Autoimmune diseases co-occurring within individuals and within families: a systematic review

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    BACKGROUND: Autoimmune diseases have been observed to coexist both within individuals and within families. It is unclear whether clinical reports of comorbid autoimmune diseases represent chance findings or true associations. This systematic review evaluates the current level of evidence on the coexistence of selected autoimmune diseases within individuals and families. We reviewed the associations among 4 TH1-associated autoimmune diseases: insulin-dependent diabetes mellitus, autoimmune (Hashimoto) thyroiditis, rheumatoid arthritis, and multiple sclerosis. METHODS: Studies quantifying the coexistence between the selected diseases, published through March 2004, were identified from Medline and Embase searches. Study eligibility was determined on the basis of preestablished criteria, and relevant data were extracted according to a fixed protocol. We determined the prevalence of comorbid autoimmune disease according to index disease and then compiled summary statistics. Heterogeneity among studies was assessed by exact likelihood ratio tests and Monte Carlo inference. RESULTS: We found 54 studies that met the eligibility criteria. Of these, 52 studies examined the coexistence of disease within individuals and 9 studies examined within-family associations. The majority of studies were uncontrolled and did not account for confounding factors. There was substantial evidence for heterogeneity among studies. Although inconclusive, the data appear to support an increased prevalence of autoimmune thyroiditis among patients with rheumatoid arthritis and those with insulin-dependent diabetes mellitus, and an inverse association between rheumatoid arthritis and multiple sclerosis. CONCLUSION: Although the available evidence does not permit firm conclusions regarding comorbidities among the selected autoimmune diseases, results are sufficiently suggestive to warrant further study.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60328/1/somers_autoimmune.pd

    Vestibular Stimulation for ADHD: Randomized Controlled Trial of Comprehensive Motion Apparatus

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    Objective: This research evaluates effects of vestibular stimulation by Comprehensive Motion Apparatus (CMA) in ADHD. Method: Children ages 6 to 12 (48 boys, 5 girls) with ADHD were randomized to thrice-weekly 30-min treatments for 12 weeks with CMA, stimulating otoliths and semicircular canals, or a single-blind control of equal duration and intensity, each treatment followed by a 20-min typing tutorial. Results: In intent-to-treat analysis (n = 50), primary outcome improved significantly in both groups (p = .0001, d = 1.09 to 1.30), but treatment difference not significant (p = .7). Control children regressed by follow-up (difference p = .034, d = 0.65), but overall difference was not significant (p = .13, d = .47). No measure showed significant treatment differences at treatment end, but one did at follow-up. Children with IQ-achievement discrepancy ≥ 1 SD showed significantly more CMA advantage on three measures. Conclusion: This study illustrates the importance of a credible control condition of equal duration and intensity in trials of novel treatments. CMA treatment cannot be recommended for combined-type ADHD without learning disorder

    Incidence of Systemic Lupus Erythematosus in the United Kingdom, 1990-1999

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    Objective. To estimate the annual incidence of systemic lupus erythematosus (SLE) over a 10-year period in the UK, and to examine age-, sex-, and region-specific rates. Methods. The study was based on the UK General Practice Research Database (GPRD), which covers 5% of the UK population. We estimated SLE incidence rates, during the period 1990–1999, among persons registered with practices contributing to the GPRD, representing >33 million person-years of observation. Results. A total of 1,638 patients with incident SLE (1,374 females, 264 males) were identified. The age-standardized SLE incidence in the UK during the 1990s was 7.89 per 100,000 (95% confidence interval [95% CI] 7.46, 8.31) for females and 1.53 per 100,000 (95% CI 1.34, 1.71) for males (overall female-to-male ratio 5.2:1). Peak incidence occurred at age 50–54 years for females and 70–74 years for males. There was a small but insignificant increase of SLE incidence over the 10 years among females but not males. No clear association between latitude and SLE incidence was found, but regional variations existed, with age-standardized rates ranging from 3.56 per 100,000 (95% CI 3.00, 4.13) for the West Midlands to 7.62 per 100,000 (95% CI 5.59, 9.65) for Northern Ireland. Conclusion. This study provides updated estimates of SLE incidence in the UK. Standard methodology throughout the study period and target population allowed for comparison of rates over time and across regions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60248/1/1_ftp.pd

    Aetiology-Specific Estimates of the Global and Regional Incidence and Mortality of Diarrhoeal Diseases Commonly Transmitted through Food

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    Diarrhoeal diseases are major contributors to the global burden of disease, particularly in children. However, comprehensive estimates of the incidence and mortality due to specific aetiologies of diarrhoeal diseases are not available. The objective of this study is to provide estimates of the global and regional incidence and mortality of diarrhoeal diseases caused by nine pathogens that are commonly transmitted through foods.We abstracted data from systematic reviews and, depending on the overall mortality rates of the country, applied either a national incidence estimate approach or a modified Child Health Epidemiology Reference Group (CHERG) approach to estimate the aetiology-specific incidence and mortality of diarrhoeal diseases, by age and region. The nine diarrhoeal diseases assessed caused an estimated 1.8 billion (95% uncertainty interval [UI] 1.1-3.3 billion) cases and 599,000 (95% UI 472,000-802,000) deaths worldwide in 2010. The largest number of cases were caused by norovirus (677 million; 95% UI 468-1,153 million), enterotoxigenic Escherichia coli (ETEC) (233 million; 95% UI 154-380 million), Shigella spp. (188 million; 95% UI 94-379 million) and Giardia lamblia (179 million; 95% UI 125-263); the largest number of deaths were caused by norovirus (213,515; 95% UI 171,783-266,561), enteropathogenic E. coli (121,455; 95% UI 103,657-143,348), ETEC (73,041; 95% UI 55,474-96,984) and Shigella (64,993; 95% UI 48,966-92,357). There were marked regional differences in incidence and mortality for these nine diseases. Nearly 40% of cases and 43% of deaths caused by these nine diarrhoeal diseases occurred in children under five years of age.Diarrhoeal diseases caused by these nine pathogens are responsible for a large disease burden, particularly in children. These aetiology-specific burden estimates can inform efforts to reduce diarrhoeal diseases caused by these nine pathogens commonly transmitted through foods
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