1,210 research outputs found

    Pierre; or, The Ambiguities: Authoritative Text, Contexts, Criticism

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    When Pierre was published one year after Moby-Dick, expectations were high. Readers expected—and Melville delivered—adventure, humor, and brilliance. Magnificent and strange, Pierre is a richly allusive novel mirroring both antebellum America and Melville’s own life

    On the topology of stationary black holes

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    We prove that the domain of outer communication of a stationary, globally hyperbolic spacetime satisfying the null energy condition must be simply connected. Under suitable additional hypotheses, this implies, in particular, that each connected component of a cross-section of the event horizon of a stationary black hole must have spherical topology.Comment: 7 pages, Late

    Centerscope

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    Centerscope, formerly Scope, was published by the Boston University Medical Center "to communicate the concern of the Medical Center for the development and maintenance of improved health care in contemporary society.

    Estrogens Attenuate Oxidative Stress and the Differentiation and Apoptosis of Osteoblasts by DNA-Binding-Independent Actions of the ERα

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    Estrogens diminish oxidative stress in bone and bone marrow, attenuate the generation of osteoblasts, and decrease the prevalence of mature osteoblast apoptosis. We have searched for the molecular mechanism of these effects using as tools a mouse model bearing an estrogen receptor α (ERα) knock-in mutation that prevents binding to DNA (ERαNERKI/−) and several osteoblast progenitor cell models expressing the wild-type ERα or the ERαNERKI/−. We report that the ability of estrogens to diminish the generation of reactive oxygen species, stimulate the activity of glutathione reductase, and decrease the phosphorylation of p66shc, as well as osteoblastogenesis and osteoblast number and apoptosis, were fully preserved in ERαNERKI/− mice, indicating that the DNA-binding function of the ERα is dispensable for all these effects. Consistent with the attenuation of osteoblastogenesis in this animal model, 17β-estradiol attenuated bone morphogenetic protein 2 (BMP-2)–induced gene transcription and osteoblast commitment and differentiation in murine and human osteoblastic cell lines. Moreover, 17β-estradiol attenuated BMP-2-induced differentiation of primary cultures of calvaria- or bone marrow–derived osteoblastic cells from ERαNERKI/− mice as effectively as in cells from wild-type littermates. The inhibitory effect of the hormone on BMP-2 signaling resulted from an ERα-mediated activation of ERKs and the phosphorylation of Smad1 at the linker region of the protein, which leads to proteasomal degradation. These results illustrate that the effects of estrogens on oxidative stress and the birth and death of osteoblasts do not require the binding of ERα to DNA response elements, but instead they result from the activation of cytoplasmic kinases. © 2010 American Society for Bone and Mineral Researc

    Thoracic Operations for Pulmonary Nodules Are Frequently Not Futile in Patients with Benign Disease

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    IntroductionPulmonary nodules often require operative resection to obtain a diagnosis. However, 10 to 30% of operations result in a benign diagnosis. Our purpose was to determine whether negative thoracic operations are futile by describing the pathological diagnoses; determining new diagnoses and treatment changes initiated based on operative findings; and assessing morbidity, mortality, and cost of the procedure.MethodsAt our academic medical center, 278 thoracic operations were performed for known or suspected cancer between January 1, 2005, and April 1, 2009. We collected and summarized data pertaining to preoperative patient and nodule characteristics, pathologic diagnosis, postoperative treatment changes resulting from surgical resection, perioperative morbidity and mortality, and hospital charges for patients with benign pathology.ResultsTwenty-three percent (65/278) of patients who underwent surgical resection for a suspicious nodule had benign pathology. We report granulomatous disease in 57%, benign tumors in 15%, fibrosis in 12%, and autoimmune and vascular diseases in 9%. Definitive diagnosis or treatment changes occurred in 85% of cases. Surgical intervention led to a new diagnosis in 69%, treatment course changes in 68% of benign cases, medication changes in 38%, new consultation in 31%, definitive treatment in 9%, and underlying disease management in 34%. There was no intraoperative, in-hospital, or 30-day mortality. Postoperative in-hospital events occurred in seven patients. The mean total cost was 25,515withameancostperdayof25,515 with a mean cost per day of 7618.ConclusionsPatients with a benign diagnosis after surgical resection for a pulmonary nodule received a new diagnosis or had a treatment course change in 85% of the cases

    Ground state and elementary excitations of single and binary Bose-Einstein condensates of trapped dipolar gases

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    We analyze the ground-state properties and the excitation spectrum of Bose-Einstein condensates of trapped dipolar particles. First, we consider the case of a single-component polarized dipolar gas. For this case we discuss the influence of the trapping geometry on the stability of the condensate as well as the effects of the dipole-dipole interaction on the excitation spectrum. We discuss also the ground state and excitations of a gas composed of two antiparallel dipolar components.Comment: 12 pages, 9 eps figures, final versio

    The importance of the local environment in the transmission of respiratory syncytial virus

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    The role of the environment in the spread of respiratory infections is poorly understood, and consequently probably underappreciated. To improve our understanding of the environmental drivers of respiratory syncytial virus (RSV) transmission, we examined RSV seasonality in two settings with unusual seasonal patterns: The Gambia (where RSV epidemics occur at different times of the year) and Southeast Florida (where RSV seasonality differs from the rest of mainland USA). We used published data to correlate the seasonality of RSV with rainfall and child nutrition in the Gambia, and with rainfall and temperature in Florida. In the Gambia, RSV incidence was more strongly and more consistently correlated with child nutrition (r=.0.73 [95%CI0.90 to 0.38]) than with rainfall (r=0.37 [95%CI 0.20 to 0.52]). In Southeast Florida RSV incidence was strongly correlated with rainfall two months previously (r=0.65 [95%CI 0.40 to 0.81]) compared to North Florida where RSV incidence was strongly correlated with temperature (r=0.75 [95%CI 0.87 to 0.56]). We propose that nutrition is the dominant environmental driver of RSV seasonality in the Gambia, while rainfall is the dominant driver of RSV seasonality in Southeast Florida. This reinforces the importance of an ecological scale understanding of disease transmission: only with such an evidence base can setting-specific recommendations be made for public health interventions that are targeted for maximum efficacy
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