169 research outputs found

    Green Space Visits among Adolescents: Frequency and Predictors in the PIAMA Birth Cohort Study.

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    Green space may influence health through several pathways, for example, increased physical activity, enhanced social cohesion, reduced stress, and improved air quality. For green space to increase physical activity and social cohesion, spending time in green spaces is likely to be important

    Letter from the Citizens of Ommen to the Governor of Overijssel

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    Sixteen citizens of Ommen sent a communication to the Governor of the Province that they saw no need for him to send a military detachment to Ommen now that the disturbances had ended. Besides, a relatively few people were the troublemakers. The billeting of military people will be a great burden to the citizens of Ommen.https://digitalcommons.hope.edu/vrp_1830s/1048/thumbnail.jp

    Local Chirality of Low-Lying Dirac Eigenmodes and the Instanton Liquid Model

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    The reasons for using low-lying Dirac eigenmodes to probe the local structure of topological charge fluctuations in QCD are discussed, and it is pointed out that the qualitative double-peaked behavior of the local chiral orientation probability distribution in these modes is necessary, but not sufficient for dominance of instanton-like fluctuations. The results with overlap Dirac operator in Wilson gauge backgrounds at lattice spacings ranging from a~0.04 fm to a~0.12 fm are reported, and it is found that the size and density of local structures responsible for double-peaking of the distribution are in disagreement with the assumptions of the Instanton Liquid Model. More generally, our results suggest that vacuum fluctuations of topological charge are not effectively dominated by locally quantized (integer-valued) lumps in QCD.Comment: 29 pages, 13 figures; v2: minor improvements in presentation, results and conclusions unchanged, version to appear in PR

    Remarkable spatial variation in the seroprevalence of Coxiella burnetii after a large Q fever epidemic.

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    Prior to the 2007-2010 Q fever epidemic in the Netherlands, the seroprevalence of antibodies against Coxiella burnetii in the general population was 1.5%, which is low compared to other countries. We aimed to determine the seroprevalence after the Q fever epidemic among people living in the affected area, compare the seroprevalence with the incidence of Q fever notifications during the 2007-2010 Q fever epidemic, and to identify farm exposures associated with having antibodies against C. burnetii

    Nuclear Polarization of Molecular Hydrogen Recombined on a Non-metallic Surface

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    The nuclear polarization of H2\mathrm{H}_2 molecules formed by recombination of nuclear polarized H atoms on the surface of a storage cell initially coated with a silicon-based polymer has been measured by using the longitudinal double-spin asymmetry in deep-inelastic positron-proton scattering. The molecules are found to have a substantial nuclear polarization, which is evidence that initially polarized atoms retain their nuclear polarization when absorbed on this type of surfac

    Flavor decomposition of the sea quark helicity distributions in the nucleon from semi-inclusive deep-inelastic scattering

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    Double-spin asymmetries of semi-inclusive cross sections for the production of identified pions and kaons have been measured in deep-inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with re-analyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.Comment: 5 pages, 3 figure

    Single-spin asymmetries in semi-inclusive deep-inelastic scattering on a transversely polarized hydrogen target

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    Single-spin asymmetries for semi-inclusive electroproduction of charged pions in deep-inelastic scattering of positrons are measured for the first time with transverse target polarization. The asymmetry depends on the azimuthal angles of both the pion (ϕ\phi) and the target spin axis (ϕS\phi_S) about the virtual photon direction and relative to the lepton scattering plane. The extracted Fourier component \cmpi is a signal of the previously unmeasured quark transversity distribution, in conjunction with the so-called Collins fragmentation function, also unknown. The Fourier component \smpi of the asymmetry arises from a correlation between the transverse polarization of the target nucleon and the intrinsic transverse momentum of quarks, as represented by the previously unmeasured Sivers distribution function. Evidence for both signals is observed, but the Sivers asymmetry may be affected by exclusive vector meson productio

    Quark helicity distributions in the nucleon for up, down, and strange quarks from semi--inclusive deep--inelastic scattering

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    Polarized deep--inelastic scattering data on longitudinally polarized hydrogen and deuterium targets have been used to determine double spin asymmetries of cross sections. Inclusive and semi--inclusive asymmetries for the production of positive and negative pions from hydrogen were obtained in a re--analysis of previously published data. Inclusive and semi--inclusive asymmetries for the production of negative and positive pions and kaons were measured on a polarized deuterium target. The separate helicity densities for the up and down quarks and the anti--up, anti--down, and strange sea quarks were computed from these asymmetries in a ``leading order'' QCD analysis. The polarization of the up--quark is positive and that of the down--quark is negative. All extracted sea quark polarizations are consistent with zero, and the light quark sea helicity densities are flavor symmetric within the experimental uncertainties. First and second moments of the extracted quark helicity densities in the measured range are consistent with fits of inclusive data

    О сущности языковой компетенции

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    В статье даётся характеристика сущностных сторон языковой компетенции как био и социального и интеллектуального феномена.У статті подається характеристика сутнісних сторін мовної компетенції як біо та соціального та інтелектуального феномену.The characteristics of essential aspects of language competency as bio- and social and intellectual phenomenon is given in the article

    Evidence for a narrow |S|=1 baryon state at a mass of 1528 MeV in quasi-real photoproduction

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    Evidence for a narrow baryon state is found in quasi-real photoproduction on a deuterium target through the decay channel p K^0_S --> p pi^+ pi^-. A peak is observed in the p K^0_S invariant mass spectrum at 1528 +/- 2.6 (stat) +/-2.1 (syst) MeV. Depending on the background model,the naive statistical significance of the peak is 4--6 standard deviations and its width may be somewhat larger than the experimental resolution of sigma=4.3 -- 6.2 MeV. This state may be interpreted as the predicted S=+1 exotic Theta^{+}(uuddbar(s)) pentaquark baryon. No signal for an hypothetical Theta^{++} baryon was observed in the pK^+ invariant mass distribution. The absence of such a signal indicates that an isotensor Theta is excluded and an isovector Theta is unlikely.Comment: 8 pages, 4 figure
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