947 research outputs found

    The radio-luminosity - black hole mass correlation for quasars from the FIRST Bright Quasar Survey, and a ``unification scheme'' for radio-loud and radio-quiet quasars

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    Several independent lines of evidence now point to a correlation between black hole mass, M_bh, and radio-luminosity. In this paper we discuss the correlation for quasars from the FIRST Bright Quasar Survey (FBQS), using black hole mass estimates from Hbeta linewidths. The FBQS objects fill in the gap between the radio-loud and radio-quiet quasars in the radio-luminosity - optical-luminosity plane, and we find that they fill the corresponding gap in the M_bh - radio luminosity correlation. There is thus a continuous variation of radio luminosity with M_bh, and no evidence for a ``switch'' at some set of critical parameter values which turns on powerful radio jets. By combining the FBQS data with that for quasars from the Palomar-Green survey we find evidence for a dependence of radio-luminosity on accretion rate relative to the Eddington limit, L/L_Edd, as well as on M_bh, consistent with the well-known radio-optical correlation for radio-loud quasars. We therefore suggest a new scheme to ``unify'' radio-loud and radio-quiet objects in which radio luminosity scales proportional to M_bh^{1.9+/-0.2}(L/L_Edd)^{1.0} for L/L_Edd~0.1, with an apparently weaker accretion rate dependence at low L/L_Edd. The scatter about this relation is +/-1.1 dex, and may well hide significant contributions from other physical effects, such as black hole spin and radio source environment.Comment: 7 pages, 4 figures, accepted for publication in ApJ Letter

    Global Emergency Medicine: A Review of the Literature From 2012

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    Objectives The Global Emergency Medicine Literature Review ( GEMLR ) conducts an annual search of peer‐reviewed and grey literature relevant to global emergency medicine ( EM ) to identify, review, and disseminate the most important new research in this field to a worldwide audience of academics and clinical practitioners. Methods This year, our search identified 4,818 articles written in six languages. These articles were distributed among 20 reviewers for initial screening based on their relevance to the field of global EM . Two additional reviewers searched and screened the grey literature. A total of 224 articles were deemed appropriate by at least one reviewer and were approved by their editor for formal scoring of overall quality and importance. Results Of the 224 articles that met our predetermined inclusion criteria, 56% were categorized as Emergency Care in Resource‐limited Settings, 18% as EM development, and 26% as Disaster and Humanitarian Response. A total of 28 articles received scores of 16 or higher and were selected for formal summary and critique. Inter‐rater reliability for two reviewers using our scoring system was good, with an intraclass correlation coefficient of 0.625 (95% confidence interval = 0.512 to 0.711). Conclusions In 2012 there were more disaster and humanitarian response articles than in previous years. As in prior years, the majority of articles addressed the acute management of infectious diseases or the care of vulnerable populations such as children and pregnant women. Resumen Medicina de Urgencias y Emergencias Global: Una Revisión de la Literatura de 2012 Objetivos La revisión de la literatura publicada en Medicina de Urgencias y Emergencias ( MUE ) global comporta una búsqueda anual de los trabajos relevantes para la MUE global, tanto publicados tras revisión por pares como corresponedientes a literatura gris. La finalidad es identificar, revisar y diseminar las investigaciones novedosas más importantes en este campoa médicos clínicos y universitarios de todo el mundo. Metodología Este año, nuestra búsqueda identificó 4.818 artículos escritos en seis lenguas. Estos artículos se distribuyeron entre 20 revisores para el despistaje inicial basándose en su relevancia para el campo de la MUE global. Dos revisores adicionales buscaron y filtraron la literatura gris. Un total de 224 artículos se consideraron apropiados por al menos un revisor, y se aprobaron por su editor para la puntuación formal de la calidad e importancia totales. Resultados De los 224 artículos que cumplieron nuestros criterios de inclusión predeterminados, un 56% se clasificaron como atención de urgencias y emergencias en ámbitos de recursos limitados, un 18% como desarrollo de la MUE y un 26% como catástrofes y respuesta humanitaria. Un total de 28 artículos recibieron una puntuación de 16 o más y se seleccionaron para el resumen y la crítica formal. La fiabilidad interobservador para los 2 revisores usando nuestro sistema de puntuación fue buena, con un coeficiente de correlación intraclase de 0,625 ( IC 95% = 0,512 a 0,711). Conclusiones En 2012 hubo más artículos sobre catástrofes y respuesta humanitaria que en años anteriores. Como en los años previos, la mayoría de los artículos valoraron el manejo agudo de enfermedades infecciosas o la atención de poblaciones vulnerables como los niños y las mujeres embarazadas.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99685/1/acem12173.pd

    Economic analysis of a transesophageal echocardiography-guided approach to cardioversion of patients with atrial fibrillation The ACUTE economic data at eight weeks

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    AbstractObjectivesThe aim of this study was to compare the relative cost of a transesophageal echocardiography (TEE)-guided strategy versus conventional strategy for patients with atrial fibrillation (AF) >2 days duration undergoing electrical cardioversion over an eight-week period.BackgroundThe Assessment of Cardioversion Using Transesophageal Echocardiography (ACUTE) trial found no difference in embolic rates between the two approaches. However, the TEE-guided strategy had a shorter time to cardioversion and a lower rate of composite bleeding. While similar clinical efficacy was concluded, the relative cost of these two strategies has not been explored.MethodsTwo economic approaches were employed in the ACUTE trial. The first approach was based on hospital charge data from complete hospital Universal Billing Code of 1992 forms, a detailed hospital charge questionnaire, or imputation. Regression analysis was used to investigate the added cost of adverse events. The second economic approach involved the development of an independent analytic model simulating treatment and actual ACUTE outcome costs as a validation of clinically derived data. Sensitivity analysis was performed on the analytic model to investigate the potential range in cost differences between the strategies.ResultsA total of 833 of the 1,222 patients were enrolled from 53 U.S. sites; TEE-guided (n = 420) and conventional (n = 413). At eight-week follow-up, total mean costs did not significantly differ between the two groups, respectively (6,508vs.6,508 vs. 6,239; difference of $269; p = 0.50). Cumulative costs were 24% higher in the conventional group, primarily due to increased incidence of bleeding and hospital costs associated with bleeding. A separate analytic model showed that treatment costs were higher for the TEE-guided strategy, but outcome costs were higher for the conventional strategy. Sensitivity analysis of the analytic model illustrated that varying the incidence and cost of major bleeding and the cost of TEE had the greatest impact on cost differences between the two groups.ConclusionsIn patients with AF >2 days duration undergoing electrical cardioversion, the TEE-guided group showed little difference in patient costs compared with the conventional group. The TEE strategy had higher initial treatment costs but lower outcome-associated costs. Cumulative costs were 24% higher in the conventional group, primarily due to bleeding. The TEE-guided strategy is an economically feasible approach compared with the conventional strategy

    Calorie restriction in humans inhibits the PI3K/AKT pathway and induces a younger transcription profile

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    Caloric restriction (CR) and down-regulation of the insulin/IGF pathway are the most robust interventions known to increase longevity in lower organisms. However, little is known about the molecular adaptations induced by CR in humans. Here, we report that long-term CR in humans inhibits the IGF-1/insulin pathway in skeletal muscle, a key metabolic tissue. We also demonstrate that CR induces dramatic changes of the skeletal muscle transcriptional profile that resemble those of younger individuals. Finally, in both rats and humans, CR evoked similar responses in the transcriptional profiles of skeletal muscle. This common signature consisted of three key pathways typically associated with longevity: IGF-1/insulin signaling, mitochondrial biogenesis, and inflammation. Furthermore, our data identify promising pathways for therapeutic targets to combat age-related diseases and promote health in humans.American Federation for Aging ResearchNational Center for Research Resources (U.S.) (Grant UL1 RR024992)National Institute of Diabetes and Digestive and Kidney Diseases (U.S.) (Grant P30DK056341

    Altered Intrinsic Functional Brain Architecture in Children at Familial Risk of Major Depression

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    Background Neuroimaging studies of patients with major depression have revealed abnormal intrinsic functional connectivity measured during the resting state in multiple distributed networks. However, it is unclear whether these findings reflect the state of major depression or reflect trait neurobiological underpinnings of risk for major depression. Methods We compared resting-state functional connectivity, measured with functional magnetic resonance imaging, between unaffected children of parents who had documented histories of major depression (at-risk, n = 27; 8–14 years of age) and age-matched children of parents with no lifetime history of depression (control subjects, n = 16). Results At-risk children exhibited hyperconnectivity between the default mode network and subgenual anterior cingulate cortex/orbital frontal cortex, and the magnitude of connectivity positively correlated with individual symptom scores. At-risk children also exhibited 1) hypoconnectivity within the cognitive control network, which also lacked the typical anticorrelation with the default mode network; 2) hypoconnectivity between left dorsolateral prefrontal cortex and subgenual anterior cingulate cortex; and 3) hyperconnectivity between the right amygdala and right inferior frontal gyrus, a key region for top-down modulation of emotion. Classification between at-risk children and control subjects based on resting-state connectivity yielded high accuracy with high sensitivity and specificity that was superior to clinical rating scales. Conclusions Children at familial risk for depression exhibited atypical functional connectivity in the default mode, cognitive control, and affective networks. Such task-independent functional brain measures of risk for depression in children could be used to promote early intervention to reduce the likelihood of developing depression

    The impact of FADS genetic variants on ω6 polyunsaturated fatty acid metabolism in African Americans

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    <p>Abstract</p> <p>Background</p> <p>Arachidonic acid (AA) is a long-chain omega-6 polyunsaturated fatty acid (PUFA) synthesized from the precursor dihomo-gamma-linolenic acid (DGLA) that plays a vital role in immunity and inflammation. Variants in the Fatty Acid Desaturase (<it>FADS</it>) family of genes on chromosome 11q have been shown to play a role in PUFA metabolism in populations of European and Asian ancestry; no work has been done in populations of African ancestry to date.</p> <p>Results</p> <p>In this study, we report that African Americans have significantly higher circulating levels of plasma AA (p = 1.35 × 10<sup>-48</sup>) and lower DGLA levels (p = 9.80 × 10<sup>-11</sup>) than European Americans. Tests for association in N = 329 individuals across 80 nucleotide polymorphisms (SNPs) in the Fatty Acid Desaturase (<it>FADS</it>) locus revealed significant association with AA, DGLA and the AA/DGLA ratio, a measure of enzymatic efficiency, in both racial groups (peak signal p = 2.85 × 10<sup>-16 </sup>in African Americans, 2.68 × 10<sup>-23 </sup>in European Americans). Ancestry-related differences were observed at an upstream marker previously associated with AA levels (rs174537), wherein, 79-82% of African Americans carry two copies of the G allele compared to only 42-45% of European Americans. Importantly, the allelic effect of the G allele, which is associated with <it>enhanced </it>conversion of DGLA to AA, on enzymatic efficiency was similar in both groups.</p> <p>Conclusions</p> <p>We conclude that the impact of <it>FADS </it>genetic variants on PUFA metabolism, specifically AA levels, is likely more pronounced in African Americans due to the larger proportion of individuals carrying the genotype associated with increased FADS1 enzymatic conversion of DGLA to AA.</p

    The One with the Feminist Critique: Revisiting Millennial Postfeminism with Friends

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    In the aftermath of its initial broadcast run, iconic millennial sitcom Friends (NBC, 1994–2004) generated some quality scholarship interrogating its politics of gender. But as a site of analysis, it remains a curious, almost structuring absence from the central canon of the first wave of feminist criticism of postfeminist culture. This absence is curious not only considering the place of Friends at the forefront of millennial popular culture but also in light of its long-term syndication in countries across the world since that time. And it is structuring in the sense that Friends was the stage on which many of the familiar tropes of postfeminism interrogated across the body of work on it appear in retrospect to have been tried and tested. This article aims to contribute toward redressing this absence through interrogation and contextualization of the series’ negotiation of a range of structuring tropes of postfeminist media discourse, and it argues for Friends as an unacknowledged ur-text of millennial postfeminism
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