211 research outputs found
More than 41% of the zeros of the zeta function are on the critical line
We prove that more than 41% of the zeros of the zeta function are on the
critical line.Comment: 23 pages; v2: added a new paragraph on pp.1-2, minor correction
A Complex Interaction Between Reduced Reelin Expression and Prenatal Organophosphate Exposure Alters Neuronal Cell Morphology.
Genetic and environmental factors are both likely to contribute to neurodevelopmental disorders including schizophrenia, autism spectrum disorders, and major depressive disorders. Prior studies from our laboratory and others have demonstrated that the combinatorial effect of two factors-reduced expression of reelin protein and prenatal exposure to the organophosphate pesticide chlorpyrifos oxon-gives rise to acute biochemical effects and to morphological and behavioral phenotypes in adolescent and young adult mice. In the current study, we examine the consequences of these factors on reelin protein expression and neuronal cell morphology in adult mice. While the cell populations that express reelin in the adult brain appear unchanged in location and distribution, the levels of full length and cleaved reelin protein show persistent reductions following prenatal exposure to chlorpyrifos oxon. Cell positioning and organization in the hippocampus and cerebellum are largely normal in animals with either reduced reelin expression or prenatal exposure to chlorpyrifos oxon, but cellular complexity and dendritic spine organization is altered, with a skewed distribution of immature dendritic spines in adult animals. Paradoxically, combinatorial exposure to both factors appears to generate a rescue of the dendritic spine phenotypes, similar to the mitigation of behavioral and morphological changes observed in our prior study. Together, our observations support an interaction between reelin expression and chlorpyrifos oxon exposure that is not simply additive, suggesting a complex interplay between genetic and environmental factors in regulating brain morphology
Leiomyosarcoma Arising in the Pancreatic Duct: A Case Report and Review of the Current Literature
Context. Leiomyosarcomas are rare malignant smooth muscle tumors that may arise in any organ or tissue that contains smooth muscle, commonly within the gastrointestinal tract. They are most often found in the stomach, large and small intestines, and retroperitoneum. Primary pancreatic leiomyosarcoma is extremely rare, and to the best of our knowledge only 30 cases have been reported in the world literature since 1951. Our case represents the first to have a clear origin from the main pancreatic duct. Case Report. This case was diagnosed in a large, tertiary care center in Tampa, Florida. Pertinent information was obtained from chart review and interdepartmental collaboration. A mass in the tail of the pancreas was identified with large pleomorphic and spindle-shaped cells. Immunohistochemistry for vimentin, smooth muscle actin, and desmin was positive. All remaining immunohistochemical markers performed were negative. The tumor clearly originated from the pancreatic duct wall, filled and expanded the duct lumen, and was covered with a layer of benign biliary epithelium. Conclusion. Leiomyosarcoma of the pancreas is an extremely rare malignancy with few reported cases in the literature. The prognosis is poor, and treatment consists of alleviating symptoms and pain management. To our knowledge, this represents the first reported case demonstrating clear origin of a leiomyosarcoma from the pancreatic duct
Validation and Calibration of Nuclear Thermal Hydraulics Multiscale Multiphysics Models - Subcooled Flow Boiling Study
In addition to validation data plan, development of advanced techniques for calibration and validation of complex multiscale, multiphysics nuclear reactor simulation codes are a main objective of the CASL VUQ plan. Advanced modeling of LWR systems normally involves a range of physico-chemical models describing multiple interacting phenomena, such as thermal hydraulics, reactor physics, coolant chemistry, etc., which occur over a wide range of spatial and temporal scales. To a large extent, the accuracy of (and uncertainty in) overall model predictions is determined by the correctness of various sub-models, which are not conservation-laws based, but empirically derived from measurement data. Such sub-models normally require extensive calibration before the models can be applied to analysis of real reactor problems. This work demonstrates a case study of calibration of a common model of subcooled flow boiling, which is an important multiscale, multiphysics phenomenon in LWR thermal hydraulics. The calibration process is based on a new strategy of model-data integration, in which, all sub-models are simultaneously analyzed and calibrated using multiple sets of data of different types. Specifically, both data on large-scale distributions of void fraction and fluid temperature and data on small-scale physics of wall evaporation were simultaneously used in this work’s calibration. In a departure from traditional (or common-sense) practice of tuning/calibrating complex models, a modern calibration technique based on statistical modeling and Bayesian inference was employed, which allowed simultaneous calibration of multiple sub-models (and related parameters) using different datasets. Quality of data (relevancy, scalability, and uncertainty) could be taken into consideration in the calibration process. This work presents a step forward in the development and realization of the “CIPS Validation Data Plan” at the Consortium for Advanced Simulation of LWRs to enable quantitative assessment of the CASL modeling of Crud-Induced Power Shift (CIPS) phenomenon, in particular, and the CASL advanced predictive capabilities, in general. This report is prepared for the Department of Energy’s Consortium for Advanced Simulation of LWRs program’s VUQ Focus Area
Film boiling heat transfer and vapour film collapse on spheres, cylinders and plane surfaces
Copyright @ 2009 Elsevier B.V. The final version of this article may be viewed at the link below.An experimental study of transient film boiling was conducted, with different coolant velocities, on two spheres with different diameters, two cylindrical specimens of different lengths in parallel flow, a cylinder in cross flow and two flat plates with different lengths. A frame by frame photographic study on the nature of the vapour/liquid interface and the collapse modes has revealed a new mode for film collapse, in which an explosive liquid–solid contact is followed by film re-formation and the motion of a quench front over the hot surface. Steady state tests were carried out on a plate similar to the short plate used in the transient experiments and the heat transfer, film stability and collapse results are compared with those of the transient investigation.
Heat transfer coefficients and heat fluxes during film boiling were found essentially to depend on specimen temperature and water subcooling. In contrast, the influences on heat transfer of specimen size and water velocity were relatively small for the ranges studied. A theoretical model predicted heat transfer coefficients to within 10% of experimental values for water subcoolings above 10 K and within 30% in all cases
Curricula and methods for physician compassion training: protocol for a systematic review
Introduction: Compassionate patient care has been associated with improved clinical outcomes for patients. However, current evidence suggests that healthcare is experiencing a compassion crisis, with physicians frequently overlooking opportunities to treat patients with compassion. Although there is evidence that compassionate care can be enhanced through training interventions, it is currently unclear what specific skills and behaviours ought to be taught and how best to transfer this information to the learner. The objectives of this systematic review are to collate the world’s literature on compassion training to determine (1) the specific skills and behaviours that should be taught (curriculum), and (2) the methods of training that are most effective at improving compassionate patient care
Curricula for empathy and compassion training in medical education: A systematic review.
BACKGROUND: Empathy and compassion are vital components of health care quality; however, physicians frequently miss opportunities for empathy and compassion in patient care. Despite evidence that empathy and compassion training can be effective, the specific behaviors that should be taught remain unclear. We synthesized the biomedical literature on empathy and compassion training in medical education to find the specific curricula components (skills and behaviors) demonstrated to be effective.
METHODS: We searched CENTRAL, MEDLINE, EMBASE, and CINAHL using a previously published comprehensive search strategy. We screened reference lists of the articles meeting inclusion criteria to identify additional studies for potential inclusion. Study inclusion criteria were: (1) intervention arm in which subjects underwent an educational curriculum aimed at enhancing empathy and/or compassion; (2) clearly defined control arm in which subjects did not receive the curriculum; (3) curriculum was tested on physicians (or physicians-in-training); and (4) outcome measure assessing the effect of the curriculum on physician empathy and/or compassion. We performed a qualitative analysis to collate and tabulate effects of tested curricula according to recommended methodology from the Cochrane Handbook. We used the Cochrane Collaboration\u27s tool for assessing risk of bias.
RESULTS: Fifty-two studies (total n = 5,316) met inclusion criteria. Most (75%) studies found that the tested curricula improved physician empathy and/or compassion on at least one outcome measure. We identified the following key behaviors to be effective: (1) sitting (versus standing) during the interview; (2) detecting patients\u27 non-verbal cues of emotion; (3) recognizing and responding to opportunities for compassion; (4) non-verbal communication of caring (e.g. eye contact); and (5) verbal statements of acknowledgement, validation, and support. These behaviors were found to improve patient perception of physician empathy and/or compassion.
CONCLUSION: Evidence suggests that training can enhance physician empathy and compassion. Training curricula should incorporate the specific behaviors identified in this report
Curricula for Empathy and Compassion Training in Medical Education: A Systematic Review.
BACKGROUND: Empathy and compassion are vital components of health care quality; however, physicians frequently miss opportunities for empathy and compassion in patient care. Despite evidence that empathy and compassion training can be effective, the specific behaviors that should be taught remain unclear. We synthesized the biomedical literature on empathy and compassion training in medical education to find the specific curricula components (skills and behaviors) demonstrated to be effective.
METHODS: We searched CENTRAL, MEDLINE, EMBASE, and CINAHL using a previously published comprehensive search strategy. We screened reference lists of the articles meeting inclusion criteria to identify additional studies for potential inclusion. Study inclusion criteria were: (1) intervention arm in which subjects underwent an educational curriculum aimed at enhancing empathy and/or compassion; (2) clearly defined control arm in which subjects did not receive the curriculum; (3) curriculum was tested on physicians (or physicians-in-training); and (4) outcome measure assessing the effect of the curriculum on physician empathy and/or compassion. We performed a qualitative analysis to collate and tabulate effects of tested curricula according to recommended methodology from the Cochrane Handbook. We used the Cochrane Collaboration\u27s tool for assessing risk of bias.
RESULTS: Fifty-two studies (total n = 5,316) met inclusion criteria. Most (75%) studies found that the tested curricula improved physician empathy and/or compassion on at least one outcome measure. We identified the following key behaviors to be effective: (1) sitting (versus standing) during the interview; (2) detecting patients\u27 non-verbal cues of emotion; (3) recognizing and responding to opportunities for compassion; (4) non-verbal communication of caring (e.g. eye contact); and (5) verbal statements of acknowledgement, validation, and support. These behaviors were found to improve patient perception of physician empathy and/or compassion.
CONCLUSION: Evidence suggests that training can enhance physician empathy and compassion. Training curricula should incorporate the specific behaviors identified in this report
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