315 research outputs found

    Bystander Intervention in Football and Sports. A Quasi-Experimental Feasibility Study of a Bystander Violence Prevention Program in the United Kingdom

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    This is the final version. Available on open access from SAGE Publications via the DOI in this recordIn recent years, social campaigns and high-profile cases have brought increased attention to violence against women. Athletes can be role models, shaping both prosocial and antisocial attitudes. Their engagement in violence prevention could be an effective tool to tackle violence against women through bystander intervention. This part of a mixed-method feasibility study reports on the quantitative evaluation of an evidence-led bystander program, Football Onside, implemented at a football club in South West England in June 2018 to February 2020. The study employed a quasi-experimental design with intervention and control groups. Football coaches and club members (n = 50) completed measures of rape and domestic abuse myths, bystander intent and efficacy, self-reported bystander behaviors, readiness for change, perceptions of peer helping and myth acceptance, law knowledge, and program evaluation. Fidelity was also assessed. The analysis compared between- and within-group differences in mean changes over time using mixed-effects models. Participant ratings of learning outcomes were high, and fidelity was maintained throughout the intervention. Between-group comparison revealed mixed results, with greater improvements in the intervention group for bystander intent and efficacy at post-test and follow-up, domestic abuse myths at post-test, and rape myth acceptance at follow-up. Model contrasts for within intervention group revealed improvements in rape and domestic abuse myth acceptance, bystander intent and efficacy, perceived law knowledge at both time points, and perceived peer myths and helping at post-test. At follow-up, intervention participants reported significantly higher engagement in bystander behaviors. No significant effects were found for perceived importance of legal knowledge. Our research highlights the potential efficacy of a bystander program tailored for football club members. Cluster-randomized control trials are now required to examine bystander attitudes and behavior change processes among professional athletes.University of ExeterEconomic and Social Research Council (ESRC

    Search for Axionlike and Scalar Particles with the NA64 Experiment

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    We carried out a model-independent search for light scalar (s) and pseudoscalar axionlike (a) particles that couple to two photons by using the high-energy CERN SPS H4 electron beam. The new particles, if they exist, could be produced through the Primakoff effect in interactions of hard bremsstrahlung photons generated by 100 GeV electrons in the NA64 active dump with virtual photons provided by the nuclei of the dump. The a(s) would penetrate the downstream HCAL module, serving as shielding, and would be observed either through their a(s)γγa(s)\to\gamma \gamma decay in the rest of the HCAL detector or as events with large missing energy if the a(s) decays downstream of the HCAL. This method allows for the probing the a(s) parameter space, including those from generic axion models, inaccessible to previous experiments. No evidence of such processes has been found from the analysis of the data corresponding to 2.84×10112.84\times10^{11} electrons on target allowing to set new limits on the a(s)γγa(s)\gamma\gamma-coupling strength for a(s) masses below 55 MeV.Comment: This publication is dedicated to the memory of our colleague Danila Tlisov. 7 pages, 5 figures, revised version accepted for publication in Phys. Rev. Let

    Fully human anti-CD39 antibody potently inhibits ATPase activity in cancer cells via uncompetitive allosteric mechanism

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    The extracellular ATP/adenosine axis in the tumor microenvironment (TME) has emerged as an important immune-regulatory pathway. Nucleoside triphosphate diphosphohydrolase-1 (NTPDase1), otherwise known as CD39, is highly expressed in the TME, both on infiltrating immune cells and tumor cells across a broad set of cancer indications. CD39 processes pro-inflammatory extracellular ATP to ADP and AMP, which is then processed by Ecto-5MODIFIER LETTER PRIME-nucleotidase/CD73 to immunosuppressive adenosine. Directly inhibiting the enzymatic function of CD39 via an antibody has the potential to unleash an immune-mediated anti-tumor response via two mechanisms: 1) increasing the availability of immunostimulatory extracellular ATP released by damaged and/or dying cells, and 2) reducing the generation and accumulation of suppressive adenosine within the TME. Tizona Therapeutics has engineered a novel first-in-class fully human anti-CD39 antibody, TTX-030, that directly inhibits CD39 ATPase enzymatic function with sub-nanomolar potency. Further characterization of the mechanism of inhibition by TTX-030 using CD39(+) human melanoma cell line SK-MEL-28 revealed an uncompetitive allosteric mechanism (alpha < 1). The uncompetitive mechanism of action enables TTX-030 to inhibit CD39 at the elevated ATP concentrations reported in the TME. Maximal inhibition of cellular CD39 ATPase velocity was 85%, which compares favorably to results reported for antibody inhibitors to other enzyme targets. The allosteric mechanism of TTX-030 was confirmed via mapping the epitope to a region of CD39 distant from its active site, which suggests possible models for how potent inhibition is achieved. In summary, TTX-030 is a potent allosteric inhibitor of CD39 ATPase activity that is currently being evaluated in clinical trials for cancer therapy

    Calibration of photomultiplier arrays

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    A method is described that allows calibration and assessment of the linearity of response of an array of photomultiplier tubes. The method does not require knowledge of the photomultiplier single photoelectron response model and uses science data directly, thus eliminating the need for dedicated data sets. In this manner all photomultiplier working conditions (e.g. temperature, external fields, etc.) are exactly matched between calibration and science acquisitions. This is of particular importance in low background experiments such as ZEPLIN-III, where methods involving the use of external light sources for calibration are severely constrained

    Limits on the spin-dependent WIMP-nucleon cross-sections from the first science run of the ZEPLIN-III experiment

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    We present new experimental constraints on the WIMP-nucleon spin-dependent elastic cross-sections using data from the first science run of ZEPLIN-III, a two-phase xenon experiment searching for galactic dark matter WIMPs based at the Boulby mine. Analysis of \sim450 kg\cdotdays fiducial exposure revealed a most likely signal of zero events, leading to a 90%-confidence upper limit on the pure WIMP-neutron cross-section of σn=1.8×102\sigma_n=1.8\times 10^{-2} pb at 55 GeV/c2c^2 WIMP mass. Recent calculations of the nuclear spin structure based on the Bonn CD nucleon-nucleon potential were used for the odd-neutron isotopes 129^{129}Xe and 131^{131}Xe. These indicate that the sensitivity of xenon targets to the spin-dependent WIMP-proton interaction is much lower than implied by previous calculations, whereas the WIMP-neutron sensitivity is impaired only by a factor of \sim2

    Intrinsic regulation of hemangioma involution by platelet-derived growth factor

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    Infantile hemangioma is a vascular tumor that exhibits a unique natural cycle of rapid growth followed by involution. Previously, we have shown that hemangiomas arise from CD133+ stem cells that differentiate into endothelial cells when implanted in immunodeficient mice. The same clonally expanded stem cells also produced adipocytes, thus recapitulating the involuting phase of hemangioma. In the present study, we have elucidated the intrinsic mechanisms of adipocyte differentiation using hemangioma-derived stem cells (hemSCs). We found that platelet-derived growth factor (PDGF) is elevated during the proliferating phase and may inhibit adipocyte differentiation. hemSCs expressed high levels of PDGF-B and showed sustained tyrosine phosphorylation of PDGF receptors under basal (unstimulated) conditions. Inhibition of PDGF receptor signaling caused enhanced adipogenesis in hemSCs. Furthermore, exposure of hemSCs to exogenous PDGF-BB reduced the fat content and the expression of adipocyte-specific transcription factors. We also show that these autogenous inhibitory effects are mediated by PDGF receptor-β signaling. In summary, this study identifies PDGF signaling as an intrinsic negative regulator of hemangioma involution and highlights the therapeutic potential of disrupting PDGF signaling for the treatment of hemangiomas

    Experimental study of the radiation emitted by 180-GeV/c electrons and positrons volume-reflected in a bent crystal

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    The radiation emitted by 180-GeV/c volume-reflected electrons and positrons impinging on a bent crystal has been measured by the H8RD22 Collaboration on the H8 beamline at the CERN SPS. A dedicated spectrometer has been developed to measure high-energy photon spectra (up to similar to 100 GeV) under volume reflection: photon and charged particle beams have been separated by a bending magnet and leptons were detected and tagged by microstrip silicon detectors and a Pb-scintillator sampling calorimeter. A comparison between the experimental and analytical data for the amorphous and volume-reflection cases is presented and the differences are discussed

    Measurement and simulation of the muon-induced neutron yield in lead

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    A measurement is presented of the neutron production rate in lead by high energy cosmic-ray muons at a depth of 2850 m water equivalent (w.e.) and a mean muon energy of 260 GeV. The measurement exploits the delayed coincidences between muons and the radiative capture of induced neutrons in a highly segmented tonne scale plastic scintillator detector. Detailed Monte Carlo simulations reproduce well the measured capture times and multiplicities and, within the dynamic range of the instrumentation, the spectrum of energy deposits. By comparing measurements with simulations of neutron capture rates a neutron yield in lead of (View the MathML source) ×10-3 neutrons/muon/(g/cm2) has been obtained. Absolute agreement between simulation and data is of order 25%. Consequences for deep underground rare event searches are discussed

    Experimental study of the radiation emitted by 180-GeV/c electrons and positrons volume-reflected in a bent crystal

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    The radiation emitted by 180-GeV/c volume-reflected electrons and positrons impinging on a bent crystal has been measured by the H8RD22 Collaboration on the H8 beamline at the CERN SPS. A dedicated spectrometer has been developed to measure high-energy photon spectra (up to similar to 100 GeV) under volume reflection: photon and charged particle beams have been separated by a bending magnet and leptons were detected and tagged by microstrip silicon detectors and a Pb-scintillator sampling calorimeter. A comparison between the experimental and analytical data for the amorphous and volume-reflection cases is presented and the differences are discussed
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