1,632 research outputs found

    CPT and Lorentz Tests in Penning Traps

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    A theoretical analysis is performed of Penning-trap experiments testing CPT and Lorentz symmetry through measurements of anomalous magnetic moments and charge-to-mass ratios. Possible CPT and Lorentz violations arising from spontaneous symmetry breaking at a fundamental level are treated in the context of a general extension of the SU(3) x SU(2) x U(1) standard model and its restriction to quantum electrodynamics. We describe signals that might appear in principle, introduce suitable figures of merit, and estimate CPT and Lorentz bounds attainable in present and future Penning-trap experiments. Experiments measuring anomaly frequencies are found to provide the sharpest tests of CPT symmetry. Bounds are attainable of approximately 10−2010^{-20} in the electron-positron case and of 10−2310^{-23} for a suggested experiment with protons and antiprotons. Searches for diurnal frequency variations in these experiments could also limit certain types of Lorentz violation to the level of 10−1810^{-18} in the electron-positron system and others at the level of 10−2110^{-21} in the proton-antiproton system. In contrast, measurements comparing cyclotron frequencies are sensitive within the present theoretical framework to different kinds of Lorentz violation that preserve CPT. Constraints could be obtained on one figure of merit in the electron-positron system at the level of 10−1610^{-16}, on another in the proton-antiproton system at 10−2410^{-24}, and on a third at 10−2510^{-25} using comparisons of H−H^- ions with antiprotons.Comment: 31 pages, published in Physical Review

    Alcohol Use during Pregnancy: Considerations for Australian Policy

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    Although there is an extensive recorded history of concerns related to alcohol exposed pregnancies and possible outcomes of fetal alcohol spectrum disorder in recent scientific literature, Australia has only recently begun to accurately or systematically diagnose and record these conditions, or to provide comprehensive, coordinated, policy-guided funding, prevention, and treatment. This article discusses some considerations that can guide policy development within the Australian context including the social context and determinates of alcohol consumption during pregnancy and the need to consider the issue as one that goes beyond the decision making of individual women. The article also identifies the contribution of research to guide evidence-based policy development, including emerging evidence of epigenetics, and systematic reviews for prevention. Other policy considerations include costs, and the possibility of the prevention paradox applying to this field, with its associated impact on costs and focus of prevention

    The control, content, and consequences of edTPA: World language teacher educators’ perceptions

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    Implemented in more than 870 teacher education programs across 41 states and the District of Columbia, edTPA is marketed as a content-specific, standardized portfolio assessment of beginning teacher performance. However, concerns about edTPA and its content-specificity are pervasive. To that end, the researchers surveyed teacher educators with World Language edTPA experience (N = 88) to ascertain their perceptions of the assessment, including its impact on teacher candidates, teacher education programs, and clinical placements, as well as the resources required, support experienced, and consequences perceived as a result of its implementation. Using Cochran-Smith et al.’s (2018) framework of teacher education accountability, the researchers explore issues of control, content, and consequences related to power relationships and the World Language edTPA, centering on the assessment’s intended content-specificity, while recounting an ACTFL task force’s efforts in 2016 to influence the assessment’s content

    Responsibility and laboratory animal research governance

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    The use of animals in experiments and research remains highly contentious. Laboratory animal research governance provides guidance and regulatory frameworks to oversee the use and welfare of laboratory animals and relies heavily on the replacement, reduction, and refinement (3Rs) principles to demonstrate responsibility. However, the application of the 3Rs is criticized for being too narrow in focus and closing down societal concerns and political questions about the purpose of animal laboratory research. These critiques challenge the legitimacy of responsibility in laboratory animal research governance and call for new approaches. With the advent of the "Responsible Research and Innovation" (RRI) agenda, we investigate whether the notion of responsibility in the controversial area of animal research governance could be enhanced by examining the 3Rs through RRI. Our analysis reveals RRI has the potential to helpfully augment the 3Rs in three key ways: recognizing the need to include a broader range of experts and publics in animal research governance; emphasizing the importance for animal research scientists of taking societal, and not just role, responsibilities into account; and acknowledging the political questions animal research raises

    A genetic analysis of ambulatory cardiorespiratory coupling.

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    This study assessed the heritability of ambulatory heart period, respiratory sinus arrhythmia (RSA), and respiration rate and tested the hypothesis that the well-established correlation between these variables is determined by common genetic factors. In 780 healthy twins and siblings, 24-h ambulatory recordings of ECG and thorax impedance were made. Genetic analyses showed considerable heritability for heart period (37%-48%), RSA (40%-55%), and respiration rate (27%-81%) at all daily periods. Significant genetic correlations were found throughout. Common genes explained large portions of the covariance between heart period and RSA and between respiration rate and RSA. During the afternoon and night, the covariance between respiration rate and RSA was completely determined by common genes. This overlap in genes can be exploited to increase the power of linkage studies to detect genetic variation influencing cardiovascular disease risk. Copyright © 2005 Society for Psychophysiological Research

    An evaluation of gender equity in different models of primary care practices in Ontario

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    Background: The World Health Organization calls for more work evaluating the effect of health care reforms on gender equity in developed countries. We performed this evaluation in Ontario, Canada where primary care models resulting from reforms co-exist. // Methods: This cross sectional study of primary care practices uses data collected in 2005-2006. Healthcare service models included in the study consist of fee for service (FFS) based, salaried, and capitation based. We compared the quality of care delivered to women and men in practices of each model. We performed multi-level, multivariate regressions adjusting for patient socio-demographic and economic factors to evaluate vertical equity, and adjusting for these and health factors in evaluating horizontal equity. We measured seven dimensions of health service delivery (e.g. accessibility and continuity) and three dimensions of quality of care using patient surveys (n = 5,361) and chart abstractions (n = 4,108). // Results: Health service delivery measures were comparable in women and men, with differences ≤ 2.2% in all seven dimensions and in all models. Significant gender differences in the health promotion subjects addressed were observed. Female specific preventive manoeuvres were more likely to be performed than other preventive care. Men attending FFS practices were more likely to receive influenza immunization than women (Adjusted odds ratio: 1.75, 95% confidence intervals (CI) 1.05, 2.92). There was no difference in the other three prevention indicators. FFS practices were also more likely to provide recommended care for chronic diseases to men than women (Adjusted difference of -11.2%, CI -21.7, -0.8). A similar trend was observed in Community Health Centers (CHC). // Conclusions: The observed differences in the type of health promotion subjects discussed are likely an appropriate response to the differential healthcare needs between genders. Chronic disease care is non equitable in FFS but not in capitation based models. We recommend that efforts to monitor and address gender based differences in the delivery of chronic disease management in primary care be pursued.Funding for the original study on which this research is based was provided by the Ontario Ministry of Health and Long Term Care Primary Health Care Transition Fund. The views expressed in this report are the views of the authors and do not necessarily reflect those of the Ontario Ministry of Health and Long Term Care

    Stacked Search for Gravitational Waves from the 2006 SGR 1900+14 Storm

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    We present the results of a LIGO search for short-duration gravitational waves (GWs) associated with the 2006 March 29 SGR 1900+14 storm. A new search method is used, "stacking'' the GW data around the times of individual soft-gamma bursts in the storm to enhance sensitivity for models in which multiple bursts are accompanied by GW emission. We assume that variation in the time difference between burst electromagnetic emission and potential burst GW emission is small relative to the GW signal duration, and we time-align GW excess power time-frequency tilings containing individual burst triggers to their corresponding electromagnetic emissions. We use two GW emission models in our search: a fluence-weighted model and a flat (unweighted) model for the most electromagnetically energetic bursts. We find no evidence of GWs associated with either model. Model-dependent GW strain, isotropic GW emission energy E_GW, and \gamma = E_GW / E_EM upper limits are estimated using a variety of assumed waveforms. The stacking method allows us to set the most stringent model-dependent limits on transient GW strain published to date. We find E_GW upper limit estimates (at a nominal distance of 10 kpc) of between 2x10^45 erg and 6x10^50 erg depending on waveform type. These limits are an order of magnitude lower than upper limits published previously for this storm and overlap with the range of electromagnetic energies emitted in SGR giant flares.Comment: 7 pages, 3 figure
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