6,873 research outputs found

    Exact renormalization group with optimal scale and its application to cosmology

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    Assuming an effective gravitational action with scale dependent coupling constants, a consistency condition for the local form of the cut-off scale is derived. The approach is applied to homogeneous cosmology and running couplings with an ultraviolet fixed point. Within the given approach this allows to derive bounds on the value of the fixed point.Comment: 11 pages, 3 figure

    Relationship Between Leisure-Time Physical Activity and Whole Body Bone Mineral Density, Human Growth Hormone, and Leptin in Women

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    The benefits of structured exercise on bone health have been well documented. However, less understood is the influence of leisure-time physical activity (LA) on BMD. PURPOSE: The purpose of this study was to examine the relationships between LA, whole body BMD, and serum levels of human growth hormone (HGH) and leptin. METHODS: One hundred two apparently healthy, premenopausal women (Mean ± SD Age: 43.1 ± 4.5 y; BMI: 26.5 ± 5.2 kg/m2; body fat: 41.6 ± 7.9 %) participated in the study. Self-reported leisure-time physical activity was quantified as total minutes of moderate to vigorous activity and then participants were separated into tertiles. Whole body BMD was determined using dual energy x-ray absoptiometry (DEXA). Serum HGH, leptin, and insulin were determined by EIA. A MANCOVA was used to evaluate differences in BMD, HGH, leptin, and LA while controlling for BMI, percentage body fat, and insulin. A multiple regression model was created with BMD as the dependant variable and HGH, leptin, LA, lean body mass (LBM), and fat mass (FM) as independent variables. RESULTS: LA was significantly different between tertiles (P \u3c 0.001). There was no significant difference between the tertiles for BMD, HGH, leptin, LBM, or FM (P = 0.167). Pearson correlation coefficient revealed a significant relationship between BMD and leptin (r = 0.229; P = 0.021), but not for HGH (r = -0.062; P = 0.535) or LA (r = -0.023; P = 0.817). Multiple regression indicated that FM had the greatest influence on BMD (beta = 0.336; P = 0.002). CONCLUSION: For these women, HGH and LA were not related to BMD and FM had the greatest influence on BMD. While mean LA was significantly different between tertiles, the nature of the activities engaged in by these women may have been insufficient to propagate differences in BMD

    Does an adequate team climate for learning predict team effectiveness and innovation potential? A psychometric validation of the Team Climate questionnaire for Learning in an organizational context

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    This paper reports the application and psychometric validation of a multi-dimensional measure of team climate for learning in a multinational organization. The research project aimed at extending previous findings at Aston Business School, using the English 33-item version of Brodbeck's Team Climate questionnaire for Learning to assess the factors that facilitate team learning in a business context and analyze its relationship to group performance, support for innovation and different effectiveness criteria chosen by the organization we cooperated with. Data concerning the TCL, the level of group development as a related process, and measures of group performance, innovation and effectiveness were gathered from 119 participants belonging to 18 work groups of the organization's headquarters and three subsidiaries in Germany, Switzerland and Belgium. The undertaken studies were carried out using a cross-sectional and correlated design. The assessment tool proved to have good psychometric properties, providing an adequate reliability, validity and power of prediction regarding team performance (R² = .81), support for innovation (R² = .69) and team effectiveness (e.g. R² = .59 as regards to the keeping of deadlines). Potential benefits derived from the application of the presented measure, limitations of the current research project and future perspectives are discussed

    Automatically generating adaptive logic to balance non-functional tradeoffs during reconfiguration

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    Increasingly, high-assurance software systems apply selfreconfiguration in order to satisfy changing functional and non-functional requirements. Most self-reconfiguration approaches identify a target system configuration to provide the desired system behavior, then apply a series of reconfiguration instructions to reach the desired target configuration. Collectively, these reconfiguration instructions define an adaptation path. Although multiple satisfying adaptation paths may exist, most self-reconfiguration approaches select adaptation paths based on a single criterion, such as minimizing reconfiguration cost. However, different adaptation paths may represent tradeoffs between reconfiguration costs and other criteria, such as performance and reliability. This paper introduces an evolutionary computationbased approach to automatically evolve adaptation paths that safely transition an executing system from its current configuration to its desired target configuration, while balancing tradeoffs between functional and non-functional requirements. The proposed approach can be applied both at design time to generate suites of adaptation paths, as well as at run time to evolve safe adaptation paths to handle changing system and environmental conditions. We demonstrate the effectiveness of this approach by applying it to the dynamic reconfiguration of a collection of remote data mirrors, with the goal of minimizing reconfiguration costs while maximizing reconfiguration performance and reliability

    Ordering in the pyrochlore antiferromagnet due to Dzyaloshinsky-Moriya interactions

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    The Heisenberg nearest neighbour antiferromagnet on the pyrochlore (3D) lattice is highly frustrated and does not order at low temperature where spin-spin correlations remain short ranged. Dzyaloshinsky-Moriya interactions (DMI) may be present in pyrochlore compounds as is shown, and the consequences of such interactions on the magnetic properties are investigated through mean field approximation and monte carlo simulations. It is found that DMI (if present) tremendously change the low temperature behaviour of the system. At a temperature of the order of the DMI a phase transition to a long range ordered state takes place. The ordered magnetic structures are explicited for the different possible DMI which are introduced on the basis of symmetry arguments. The relevance of such a scenario for pyrochlore compounds in which an ordered magnetic structure is observed experimentally is dicussed

    Case Study of Resilient Baton Rouge: Applying Depression Collaborative Care and Community Planning to Disaster Recovery.

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    BackgroundAddressing behavioral health impacts of major disasters is a priority of increasing national attention, but there are limited examples of implementation strategies to guide new disaster responses. We provide a case study of an effort being applied in response to the 2016 Great Flood in Baton Rouge.MethodsResilient Baton Rouge was designed to support recovery after major flooding by building local capacity to implement an expanded model of depression collaborative care for adults, coupled with identifying and responding to local priorities and assets for recovery. For a descriptive, initial evaluation, we coupled analysis of documents and process notes with descriptive surveys of participants in initial training and orientation, including preliminary comparisons among licensed and non-licensed participants to identify training priorities.ResultsWe expanded local behavioral health service delivery capacity through subgrants to four agencies, provision of training tailored to licensed and non-licensed providers and development of advisory councils and partnerships with grassroots and government agencies. We also undertook initial efforts to enhance national collaboration around post-disaster resilience.ConclusionOur partnered processes and lessons learned may be applicable to other communities that aim to promote resilience, as well as planning for and responding to post-disaster behavioral health needs

    A Neutron Star Binary Merger Model for GW170817/GRB170817a/SSS17a

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    The merging neutron star gravitational wave event GW170817 has been observed throughout the entire electromagnetic spectrum from radio waves to γ\gamma-rays. The resulting energetics, variability, and light curves are shown to be consistent with GW170817 originating from the merger of two neutron stars, in all likelihood followed by the prompt gravitational collapse of the massive remnant. The available γ\gamma-ray, X-ray and radio data provide a clear probe for the nature of the relativistic ejecta and the non-thermal processes occurring within, while the ultraviolet, optical and infrared emission are shown to probe material torn during the merger and subsequently heated by the decay of freshly synthesized rr-process material. The simplest hypothesis that the non-thermal emission is due to a low-luminosity short γ\gamma-ray burst (sGRB) seems to agree with the present data. While low luminosity sGRBs might be common, we show here that the collective prompt and multi-wavelength observations are also consistent with a typical, powerful sGRB seen off-axis. Detailed follow-up observations are thus essential before we can place stringent constraints on the nature of the relativistic ejecta in GW170817.Comment: 9 pages, 5 figures, accepted to ApJ Letter
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