803 research outputs found

    A comparison of theoretical line intensity ratios for Ni XII with extreme ultraviolet observations from the JET tokamak

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    Recent R-matrix calculations of electron impact excitation rates in Ni XII are used to derive the emission line ratios R1 = I (154.17 Å)/I (152.15 Å), R2 = I (152.95 Å)/I (152.15 Å) and R3 = I (160.55 Å)/I (152.15 Å). This is the first time (to our knowledge) that theoretical emission line ratios have been calculated for this ion. The ratios are found to be insensitive to changes in the adopted electron density (Ne) when Ne >= 5 × 10^11 cm−3, typical of laboratory plasmas. However, they do vary with electron temperature (Te), with for example R1 and R3 changing by factors of 1.3 and 1.8, respectively, between Te = 10^5 and 10^6 K. A comparison of the theoretical line ratios with measurements from the Joint European Torus (JET) tokamak reveals very good agreement between theory and observation for R1, with an average discrepancy of only 7%. Agreement between the calculated and experimental ratios for R2 and R3 is less satisfactory, with average differences of 30 and 33%, respectively. These probably arise from errors in the JET instrument calibration curve. However, the discrepancies are smaller than the uncertainties in the R2 and R3 measurements. Our results, in particular for R1, provide experimental support for the accuracy of the Ni XII line ratio calculations, and hence for the atomic data adopted in their derivation

    L’effetto delle operazioni di fusione e acquisizione sui profitti degli azionisti nell’industria farmaceutica

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    The purpose of this study was to quantify the excess return in shareholder security prices following initial announcements of successful horizontal pharmaceutical mergers which occurred between 1985 and 1996. An event study methodology was used to study a sample of26 fim1s involved in 14 mergers wherein transaction costs exceeded $500 million. Overall, results of the study were consistent with prior research, indicating that target-firm shareholders received a majority oft he short-term merger-related wealth effects in comparison to those received by bidder- firm shareholders

    A Path Algorithm for Constrained Estimation

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    Many least squares problems involve affine equality and inequality constraints. Although there are variety of methods for solving such problems, most statisticians find constrained estimation challenging. The current paper proposes a new path following algorithm for quadratic programming based on exact penalization. Similar penalties arise in l1l_1 regularization in model selection. Classical penalty methods solve a sequence of unconstrained problems that put greater and greater stress on meeting the constraints. In the limit as the penalty constant tends to \infty, one recovers the constrained solution. In the exact penalty method, squared penalties are replaced by absolute value penalties, and the solution is recovered for a finite value of the penalty constant. The exact path following method starts at the unconstrained solution and follows the solution path as the penalty constant increases. In the process, the solution path hits, slides along, and exits from the various constraints. Path following in lasso penalized regression, in contrast, starts with a large value of the penalty constant and works its way downward. In both settings, inspection of the entire solution path is revealing. Just as with the lasso and generalized lasso, it is possible to plot the effective degrees of freedom along the solution path. For a strictly convex quadratic program, the exact penalty algorithm can be framed entirely in terms of the sweep operator of regression analysis. A few well chosen examples illustrate the mechanics and potential of path following.Comment: 26 pages, 5 figure

    The State of Disparities in Opportunistic Infection Prophylaxis for Blacks With HIV/AIDS

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    The purpose of this review is to identify and analyze published studies that have evaluated disparities for opportunistic infection (OI) prophylaxis between Blacks and Whites with HIV/AIDS in the United States

    Hospitalizations for Cardiovascular Disease in African Americans and Whites with HIV/AIDS

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    Therapeutic advances have resulted in an epidemiological shift in the predominant causes of hospitalization for patients with HIV/AIDS. An emerging cause for hospitalization in this patient population is cardiovascular disease (CVD); however, data are limited regarding how this shift affects different racial groups. The objective of this observational, retrospective study was to evaluate the association between race and hospitalization for CVD in African Americans and whites with HIV/AIDS and to compare the types of CVD-related hospitalizations between African Americans and whites with HIV/AIDS. Approximately 1.5 million hospital discharges from the US National Hospital Discharge Surveys for the years of 1996 to 2008 were identified. After controlling for potential confounders, the odds of CVD-related hospitalization in patients with HIV/AIDS were 45% higher for African Americans than whites (odds ratio [OR]=1.45, 95% CI, 1.39–1.51). Other covariates that were associated with increased odds of hospitalization for CVD included chronic kidney disease (OR=1.43, 95% CI, 1.36–1.51), age≥50 years (OR=3.22, 95% CI, 2.94–3.54), region in the Southern United States (OR=1.17, 95% CI, 1.11–1.23), and Medicare insurance coverage (OR=1.71, 95% CI, 1.60–1.83). Male sex was not significantly associated with the study outcome (OR=0.99, 95% CI, 0.96–1.02). Compared to whites with HIV/AIDS, African Americans with HIV/AIDS had more hospitalizations for heart failure and hypertension, but fewer hospitalizations for stroke and coronary heart disease. In conclusion, African Americans with HIV/AIDS have increased odds of CVD-related hospitalization as compared to whites with HIV/AIDS. Furthermore, the most common types of CVD-related hospitalizations differ significantly in African Americans and whites. (Population Health Management 2012;16:201–207

    Obesity, chronic disease, age, and in-hospital mortality in patients with covid-19: analysis of ISARIC clinical characterisation protocol UK cohort.

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    BACKGROUND: Although age, obesity and pre-existing chronic diseases are established risk factors for COVID-19 outcomes, their interactions have not been well researched. METHODS: We used data from the Clinical Characterisation Protocol UK (CCP-UK) for Severe Emerging Infection developed by the International Severe Acute Respiratory and emerging Infections Consortium (ISARIC). Patients admitted to hospital with COVID-19 from 6th February to 12th October 2020 were included where there was a coded outcome following hospital admission. Obesity was determined by an assessment from a clinician and chronic disease by medical records. Chronic diseases included: chronic cardiac disease, hypertension, chronic kidney disease, chronic pulmonary disease, diabetes and cancer. Mutually exclusive categories of obesity, with or without chronic disease, were created. Associations with in-hospital mortality were examined across sex and age categories. RESULTS: The analysis included 27,624 women with 6407 (23.2%) in-hospital deaths and 35,065 men with 10,001 (28.5%) in-hospital deaths. The prevalence of chronic disease in women and men was 66.3 and 68.5%, respectively, while that of obesity was 12.9 and 11.1%, respectively. Association of obesity and chronic disease status varied by age (p < 0.001). Under 50 years of age, obesity and chronic disease were associated with in-hospital mortality within 28 days of admission in a dose-response manner, such that patients with both obesity and chronic disease had the highest risk with a hazard ratio (HR) of in-hospital mortality of 2.99 (95% CI: 2.12, 4.21) in men and 2.16 (1.42, 3.26) in women compared to patients without obesity or chronic disease. Between the ages of 50-69 years, obesity and chronic disease remained associated with in-hospital COVID-19 mortality, but survival in those with obesity was similar to those with and without prevalent chronic disease. Beyond the age of 70 years in men and 80 years in women there was no meaningful difference between those with and without obesity and/or chronic disease. CONCLUSION: Obesity and chronic disease are important risk factors for in-hospital mortality in younger age groups, with the combination of chronic disease and obesity being particularly important in those under 50 years of age. These findings have implications for targeted public health interventions, vaccination strategies and in-hospital clinical decision making

    Obesity, Ethnicity, and Risk of Critical Care, Mechanical Ventilation, and Mortality in Patients Admitted to Hospital with COVID-19: Analysis of the ISARIC CCP-UK Cohort.

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    OBJECTIVE: The aim of this study was to investigate the association of obesity with in-hospital coronavirus disease 2019 (COVID-19) outcomes in different ethnic groups. METHODS: Patients admitted to hospital with COVID-19 in the United Kingdom through the Clinical Characterisation Protocol UK (CCP-UK) developed by the International Severe Acute Respiratory and emerging Infections Consortium (ISARIC) were included from February 6 to October 12, 2020. Ethnicity was classified as White, South Asian, Black, and other minority ethnic groups. Outcomes were admission to critical care, mechanical ventilation, and in-hospital mortality, adjusted for age, sex, and chronic diseases. RESULTS: Of the participants included, 54,254 (age = 76 years; 45.0% women) were White, 3,728 (57 years; 41.1% women) were South Asian, 2,523 (58 years; 44.9% women) were Black, and 5,427 (61 years; 40.8% women) were other ethnicities. Obesity was associated with all outcomes in all ethnic groups, with associations strongest for black ethnicities. When stratified by ethnicity and obesity status, the odds ratios for admission to critical care, mechanical ventilation, and mortality in black ethnicities with obesity were 3.91 (3.13-4.88), 5.03 (3.94-6.63), and 1.93 (1.49-2.51), respectively, compared with White ethnicities without obesity. CONCLUSIONS: Obesity was associated with an elevated risk of in-hospital COVID-19 outcomes in all ethnic groups, with associations strongest in Black ethnicities

    Law enforcement assisted diversion : qualitative evaluation of barriers and facilitators of program implementation

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    BACKGROUND : Despite widespread interest in adoption, there has been limited systematic examination of Law Enforcement Assisted Diversion (LEAD) implementation, a model for police-led arrest diversion for those with substance use disorders (SUD). In the fall of 2017, the City of New Haven started a LEAD program. During the first 9 months of the pilot, only 2 clients were successfully diverted from arrest. Therefore, we examined the and barriers and facilitators of LEAD implementation. METHODS : We conducted semi-structured interviews and field observations of LEAD police officers and health care providers between August 2018 and June 2019. Interviews and field observations were analyzed using directed content analysis and guided by the Integrated Promoting Action on Research Implementation in Health Services framework. RESULTS : Lead professionals participated in 19 semi-structured interviews and three field observations. Barriers to arrest diversion implementation included procedural complexity of arrest diversion, concerns about reduced penalties for substance use among officers, stigma of SUDs, and a belief in a punitive role for policing. Facilitators included a positive longitudinal relationship with potential clients and an understanding of SUD as a chronic disease. CONCLUSION : We identified several barriers to LEAD implementation. Our results suggest promotion of SUD as a chronic disease, ongoing training of officers, and positive incentives for entering substance use treatment should be utilized to facilitate implementation.SUPPLEMENTARY MATERIAL : Appendix A: Interview guideThe National Institutes of Health (NIH) and the Department of Veterans Affairs.https://www.elsevier.com/locate/jsat2022-05-14hj2022Psycholog

    Darwin -— an experimental astronomy mission to search for extrasolar planets

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    As a response to ESA call for mission concepts for its Cosmic Vision 2015–2025 plan, we propose a mission called Darwin. Its primary goal is the study of terrestrial extrasolar planets and the search for life on them. In this paper, we describe different characteristics of the instrument

    RESEARCH ARTICLES Pharmacy Students&apos; Learning Styles Before and After a Problem-based Learning Experience

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    Objectives. To determine learning-style scores of second-year pharmacy students before and after a problem-based learning (PBL) teaching experience and to evaluate the relationships between scores and demographic variables. Methods. The Grasha-Reichmann Student Learning Style Scale (GRSLSS) was given to pharmacotherapy laboratory students before and after a semester-long problem-based learning class
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