300 research outputs found

    High-energy Cosmic-Ray Positrons from Hidden-Gauge-Boson Dark Matter

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    We provide a scenario in which a hidden U(1) gauge boson constitutes dark matter of the Universe and decays into the standard-model particles through a kinetic mixing with an U(1)BLU(1)_{B-L} gauge boson. Interestingly, our model can naturally account for the steep rise in the positron fraction recently reported by PAMELA. Moreover, we find that due to the charge assignment of U(1)BLU(1)_{B-L}, only a small amount of antiprotons are produced in the decay, which is also consistent with the PAMELA and other observational data.Comment: the version appeared in PL

    Family-school connections and internalizing problems among children living with asthma in urban, low-income neighborhoods

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    Children with asthma living in urban environments are at risk for experiencing internalizing problems and difficulties at school due to social context and health-related stressors. Parent confidence and participation in the school and children’s attitudes about school were explored in association with children’s depressed mood and school anxiety. Forty-five parent—child dyads were recruited from urban community health centers. Most participants were members of ethnic minority groups. Hierarchical multiple regression analyses revealed that higher levels of parent confidence in the school were associated with fewer symptoms of school anxiety in children. Children’s attitudes toward school moderated the relation between parent participation in the school and children’s depressed mood. Specifically, lower levels of parent participation were associated with higher levels of depressed mood only for children with the least positive school attitudes. Although preliminary, these results suggest the importance of attending to family—school connections to optimize the school-related psychological functioning of children living with asthma in urban environments

    Detector Description and Performance for the First Coincidence Observations between LIGO and GEO

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    For 17 days in August and September 2002, the LIGO and GEO interferometer gravitational wave detectors were operated in coincidence to produce their first data for scientific analysis. Although the detectors were still far from their design sensitivity levels, the data can be used to place better upper limits on the flux of gravitational waves incident on the earth than previous direct measurements. This paper describes the instruments and the data in some detail, as a companion to analysis papers based on the first data.Comment: 41 pages, 9 figures 17 Sept 03: author list amended, minor editorial change

    Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

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    14 p.Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change

    Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

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    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR
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