1,835 research outputs found

    The Effect of Gender Equality on International Soccer Performance

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    In this article, we propose a new estimation strategy that draws on the variation in the performance between the male and the female national soccer team within a country to identify the effect of gender equality on women’s soccer success. For this, country year fixed effects are used to control for both time-constant and time-variant country specific factors. Our results reveal that within-country differences in our proxies for gender equality explain the international soccer performance of female teams, but have no notable explanatory power for the success of male teams. This suggests that gender equality is an important determinant of female sport success

    Exploring the extended density-dependent Skyrme effective forces for normal and isospin-rich nuclei to neutron stars

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    We parameterize the recently proposed generalized Skyrme effective force (GSEF) containing extended density dependence. The parameters of the GSEF are determined by the fit to several properties of the normal and isospin-rich nuclei. We also include in our fit a realistic equation of state for the pure neutron matter up to high densities so that the resulting Skyrme parameters can be suitably used to model the neutron star with the "canonical" mass (∌1.4M⊙\sim 1.4 M_\odot). For the appropriate comparison we generate a parameter set for the standard Skyrme effective force (SSEF) using exactly the same set of the data as employed to determine the parameters of the GSEF. We find that the GSEF yields larger values for the neutron skin thickness which are closer to the recent predictions based on the isospin diffusion data. The Skyrme parameters so obtained are employed to compute the strength function for the isoscalar giant monopole, dipole and quadrupole resonances. It is found that in the case of GSEF, due to the the larger value of the nucleon effective mass the values of centroid energies for the isoscalar giant resonances are in better agreement with the corresponding experimental data in comparison to those obtained using the SSEF. We also present results for some of the key properties associated with the neutron star of "canonical" mass and for the one with the maximum mass.Comment: 45pages, 16 figure

    Characterization of Agrobacterium tumefaciens strains isolated from grapevine

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    Grapevine crown gall is predominantly induced by Agrobacterium vitis, but rarely, Agrobacterium tumefaciens may also cause this disease. We have collected 18 grapevine isolates of A. tumefaciens from distinct geographical regions and various grapevine varieties. Characterization of these strains showed that 7 of the 18 strains carried A. vitis-type octopine/cucumopine Ti plasmids, utilized tartrate, were avirulent on pea and did not respond to the virC-specific PCR primers like A. vitis. Eleven of the 18 strains carried A. tumefaciens-type Ti plasmids, did not grow on tartrate, were virulent on pea and reacted positively to virC-specific PCR primers. Two of these strains induced octopine/agropine-, and two strains induced agropine producing tumors on grapevine and/or Kalanchoe tubiflora plants. The remaining 7 strains showed the characteristic properties of A. tumefaciens nopaline strains and were sensitive to agrocin 84

    The effect of heterogeneity on invasion in spatial epidemics: from theory to experimental evidence in a model system

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    Heterogeneity in host populations is an important factor affecting the ability of a pathogen to invade, yet the quantitative investigation of its effects on epidemic spread is still an open problem. In this paper, we test recent theoretical results, which extend the established “percolation paradigm” to the spread of a pathogen in discrete heterogeneous host populations. In particular, we test the hypothesis that the probability of epidemic invasion decreases when host heterogeneity is increased. We use replicated experimental microcosms, in which the ubiquitous pathogenic fungus Rhizoctonia solani grows through a population of discrete nutrient sites on a lattice, with nutrient sites representing hosts. The degree of host heterogeneity within different populations is adjusted by changing the proportion and the nutrient concentration of nutrient sites. The experimental data are analysed via Bayesian inference methods, estimating pathogen transmission parameters for each individual population. We find a significant, negative correlation between heterogeneity and the probability of pathogen invasion, thereby validating the theory. The value of the correlation is also in remarkably good agreement with the theoretical predictions. We briefly discuss how our results can be exploited in the design and implementation of disease control strategies

    The tensor part of the Skyrme energy density functional. I. Spherical nuclei

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    We perform a systematic study of the impact of the J^2 tensor term in the Skyrme energy functional on properties of spherical nuclei. In the Skyrme energy functional, the tensor terms originate both from zero-range central and tensor forces. We build a set of 36 parameterizations, which covers a wide range of the parameter space of the isoscalar and isovector tensor term coupling constants, with a fit protocol very similar to that of the successful SLy parameterizations. We analyze the impact of the tensor terms on a large variety of observables in spherical mean-field calculations, such as the spin-orbit splittings and single-particle spectra of doubly-magic nuclei, the evolution of spin-orbit splittings along chains of semi-magic nuclei, mass residuals of spherical nuclei, and known anomalies of charge radii. Our main conclusion is that the currently used central and spin-orbit parts of the Skyrme energy density functional are not flexible enough to allow for the presence of large tensor terms.Comment: 38 pages, 36 figures; Minor correction

    Na I and Hα\alpha absorption features in the atmosphere of MASCARA-2b/KELT-20b

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    We have used the HARPS-North high resolution spectrograph (R\mathcal{R}=115 000) at TNG to observe one transit of the highly irradiated planet MASCARA-2b/KELT-20b. Using only one transit observation, we are able to clearly resolve the spectral features of the atomic sodium (Na I) doublet and the Hα\alpha line in its atmosphere, measuring absorption depths of 0.17±\pm0.03%\% and 0.59±\pm0.08%\% for a 0.75 A˚\AA passband, respectively. These absorptions are corroborated with the transmission measured from their respective transmission light curves, which show a large Rossiter-McLaughlin effect. In case of Hα\alpha, this absorption corresponds to an effective radius of Rλ/RPR_{\lambda}/R_P=1.20±\pm0.04. While the S/N of the final transmission spectrum is not sufficient to adjust different temperature profiles to the lines, we find that higher temperatures than the equilibrium are needed to explain the lines contrast. Particularly, we find that the Na I lines core require a temperature of T=4210±\pm180K and that Hα\alpha requires T=4330±\pm520K. MASCARA-2b, like other planets orbiting A-type stars, receives a large amount of UV energy from its host star. This energy excites the atomic hydrogen and produces Hα\alpha absorption, leading to the expansion and abrasion of the atmosphere. The study of other Balmer lines in the transmission spectrum would allow the determination of the atmospheric temperature profile and the calculation of the lifetime of the atmosphere. In the case of MASCARA-2b, residual features are observed in the HÎČ\beta and HÎł\gamma lines, but they are not statistically significant. More transit observations are needed to confirm our findings in Na I and Hα\alpha, and to build up enough S/N to explore the presence of HÎČ\beta and HÎł\gamma planetary absorptions.Comment: 14 pages, 12 figure

    Ultra-stable implanted 83Rb/83mKr electron sources for the energy scale monitoring in the KATRIN experiment

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    The KATRIN experiment aims at the direct model-independent determination of the average electron neutrino mass via the measurement of the endpoint region of the tritium beta decay spectrum. The electron spectrometer of the MAC-E filter type is used, requiring very high stability of the electric filtering potential. This work proves the feasibility of implanted 83Rb/83mKr calibration electron sources which will be utilised in the additional monitor spectrometer sharing the high voltage with the main spectrometer of KATRIN. The source employs conversion electrons of 83mKr which is continuously generated by 83Rb. The K-32 conversion line (kinetic energy of 17.8 keV, natural line width of 2.7 eV) is shown to fulfill the KATRIN requirement of the relative energy stability of +/-1.6 ppm/month. The sources will serve as a standard tool for continuous monitoring of KATRIN's energy scale stability with sub-ppm precision. They may also be used in other applications where the precise conversion lines can be separated from the low energy spectrum caused by the electron inelastic scattering in the substrate.Comment: 30 pages, 10 figures, 1 table, minor revision of the preprint, accepted by JINST on 5.2.201

    Husband’s Unemployment and Wife’s Labor Supply: The Added Worker Effect across Europe

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    This article investigates the responsiveness of women’s labor supply to their husband’s job loss—the so-called added worker effect. The authors contribute to the literature by taking an explicit internationally comparative perspective in analyzing the variation of the added worker effect across welfare regimes. Using longitudinal data from the European Union Statistics on Income and Living Conditions (EU-SILC) survey covering 28 European countries from 2004 to 2013, they find evidence of an added worker effect, which, however, varies over both the business cycle and the different welfare regimes in Europe. The latter result might be explained, in part, by differences in the design of the unemployment benefit system across countries, which create different incentives for the labor supply of wives of unemployed men
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