41 research outputs found

    Eta Carinae -- Physics of the Inner Ejecta

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    Eta Carinae's inner ejecta are dominated observationally by the bright Weigelt blobs and their famously rich spectra of nebular emission and absorption lines. They are dense (n_e ~ 10^7 to 10^8 cm^-3), warm (T_e ~ 6000 to 7000 K) and slow moving (~40 km/s) condensations of mostly neutral (H^0) gas. Located within 1000 AU of the central star, they contain heavily CNO-processed material that was ejected from the star about a century ago. Outside the blobs, the inner ejecta include absorption-line clouds with similar conditions, plus emission-line gas that has generally lower densities and a wider range of speeds (reaching a few hundred km/s) compared to the blobs. The blobs appear to contain a negligible amount of dust and have a nearly dust-free view of the central source, but our view across the inner ejecta is severely affected by uncertain amounts of dust having a patchy distribution in the foreground. Emission lines from the inner ejecta are powered by photoionization and fluorescent processes. The variable nature of this emission, occurring in a 5.54 yr event cycle, requires specific changes to the incident flux that hold important clues to the nature of the central object.Comment: This is Chapter 5 in a book entitled: Eta Carinae and the Supernova Impostors, Kris Davidson and Roberta M. Humphreys, editors Springe

    Racial/Ethnic Differences in Multiple Self-Care Behaviors in Adults with Diabetes

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    OBJECTIVE: To assess racial/ethnic differences in multiple diabetes self-care behaviors. DESIGN: Cross-sectional study. PARTICIPANTS: 21,459 participants with diabetes in the 2003 Behavioral Risk Factor Surveillance survey. MEASUREMENTS: The study assessed self-care behaviors including physical activity, fruits/vegetables consumption, glucose testing, and foot examination, as well as a composite of the 4 self-care behaviors across racial/ethnic groups. Multiple logistic regression was used to assess the independent association between race/ethnicity, the composite variable, and each self-care behavior controlling for covariates. STATA was used for statistical analysis. RESULTS: Overall, 6% engaged in all 4 self-care behaviors, with a range of 5% in non-insulin users to 8% in insulin users. Blacks were less likely to exercise (OR 0.63, 95% CI 0.51, 0.79), while Hispanics and “others” were not significantly different from whites. Hispanics (OR 0.64, 95% CI 0.49, 0.82) and others (OR 0.69, 95% CI 0.49, 0.96) were less likely to do home glucose testing, while blacks were not significantly different from whites. Blacks (OR 1.42, 95% CI 1.12, 1.80) were more likely to do home foot examinations, while Hispanics and others were not significantly different from whites. Blacks (OR 0.56, 95% CI 0.36, 0.87) were less likely to engage in all 4 behaviors, while Hispanics and others were not significantly different from whites. There were no significant racial/ethnic differences in fruit and vegetable consumption. CONCLUSIONS: Few patients engage in multiple self-care behaviors at recommended levels, and there are significant racial/ethnic differences in physical activity, dietary, and foot care behaviors among adults with diabetes

    Primary Language, Income and the Intensification of Anti-glycemic Medications in Managed Care: the (TRIAD) Study

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    BACKGROUND Patients who speak Spanish and/or have low socioeconomic status are at greater risk of suboptimal glycemic control. Inadequate intensification of anti-glycemic medications may partially explain this disparity. OBJECTIVE To examine the associations between primary language, income, and medication intensification. DESIGN Cohort study with 18-month follow-up. PARTICIPANTS One thousand nine hundred and thirty-nine patients with Type 2 diabetes who were not using insulin enrolled in the Translating Research into Action for Diabetes Study (TRIAD), a study of diabetes care in managed care. MEASUREMENTS Using administrative pharmacy data, we compared the odds of medication intensification for patients with baseline A1c ≥ 8%, by primary language and annual income. Covariates included age, sex, race/ethnicity, education, Charlson score, diabetes duration, baseline A1c, type of diabetes treatment, and health plan. RESULTS Overall, 42.4% of patients were taking intensified regimens at the time of follow-up. We found no difference in the odds of intensification for English speakers versus Spanish speakers. However, compared to patients with incomes 75,000 (OR 2.22, 1.53-3.24) had increased odds of intensification. This latter pattern did not differ statistically by race. CONCLUSIONS Low-income patients were less likely to receive medication intensification compared to higher-income patients, but primary language (Spanish vs. English) was not associated with differences in intensification in a managed care setting. Future studies are needed to explain the reduced rate of intensification among low income patients in managed care

    PET Molecular Targets and Near-Infrared Fluorescence Imaging of Atherosclerosis

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    PURPOSE OF REVIEW: With this review, we aim to summarize the role of positron emission tomography (PET) and near-infrared fluorescence imaging (NIRF) in the detection of atherosclerosis. RECENT FINDINGS: (18)F-FDG is an established measure of increased macrophage activity. However, due to its low specificity, new radiotracers have emerged for more specific detection of vascular inflammation and other high-risk plaque features such as microcalcification and neovascularization. Novel NIRF probes are engineered to sense endothelial damage as an early sign of plaque erosion as well as oxidized low-density lipoprotein (oxLDL) as a prime target for atherosclerosis. Integrated NIRF/OCT (optical coherence tomography) catheters enable to detect stent-associated microthrombi. Novel radiotracers can improve specificity of PET for imaging atherosclerosis. Advanced NIRF probes show promise for future application in human. Intravascular NIRF might play a prominent role in the detection of stent-induced vascular injury

    Distinct mandibular premolar crown morphology in Homo naledi and its implications for the evolution of Homo species in southern Africa

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    Homo naledi displays a combination of features across the skeleton not found in any other hominin taxon, which has hindered attempts to determine its placement within the hominin clade. Using geometric morphometrics, we assess the morphology of the mandibular premolars of the species at the enamel-dentine junction (EDJ). Comparing with specimens of Paranthropus, Australopithecus and Homo (n = 95), we find that the H. naledi premolars from the Dinaledi chamber consistently display a suite of traits (e.g., tall crown, well22 developed P3 and P4 metaconid, strongly developed P3 mesial marginal ridge, and a P3>P4 size relationship) that distinguish them from known hominin groups. Premolars from a second locality, the Lesedi Chamber, are consistent with this morphology. We also find that two specimens from South Africa, SK 96 (usually attributed to Paranthropus) and Stw 80 (Homo sp.), show similarities to the species, and we discuss a potential evolutionary link between H. naledi and hominins from Sterkfontein and Swartkrans
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