619 research outputs found

    Distributive justice with and without culture

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    Academic treatments of distributive justice normally adopt a static approach centred on resource allocation among a set of individual agents. The resulting models, expressed in mathematical language, make no allowance for culture, as they never engage with the society’s way of life or the moulding of individuals within society. This paper compares the static approach to distributive justice with a cultural one, arguing that a case for redistribution should rest upon its cultural effects in assisting well-being and social cohesion. Unless we recognise culture, we can have little understanding of why inequalities matter, where they come from, and how they might be reduced. Redistribution may be motivated by universal value judgements taken from external sources, but it also entails internal cultural changes that refashion social relations through cumulative causation. In practical terms, it has to penetrate beyond reallocating resource endowments to bring revised attitudes in a society less tolerant of unequal outcomes. Egalitarian reforms will flourish only if they generate and reflect an egalitarian culture

    Photoproduction of pions and properties of baryon resonances from a Bonn-Gatchina partial wave analysis

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    Masses, widths and photocouplings of baryon resonances are determined in a coupled-channel partial wave analysis of a large variety of data. The Bonn-Gatchina partial wave formalism is extended to include a decomposition of t- and u-exchange amplitudes into individual partial waves. The multipole transition amplitudes for γp→pπ0\gamma p\to p\pi^0 and γp→nπ+\gamma p\to n\pi^+ are given and compared to results from other analyses.Comment: 18 pages, 14 figure

    Photoproduction of phi(1020) mesons on the proton at large momentum transfer

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    The cross section for Ï•\phi meson photoproduction on the proton has been measured for the first time up to a four-momentum transfer -t = 4 GeV^2, using the CLAS detector at the Thomas Jefferson National Accelerator Facility. At low four-momentum transfer, the differential cross section is well described by Pomeron exchange. At large four-momentum transfer, above -t = 1.8 GeV^2, the data support a model where the Pomeron is resolved into its simplest component, two gluons, which may couple to any quark in the proton and in the Ï•\phi.Comment: 5 pages; 7 figure

    Invader removal triggers competitive release in a threatened avian predator

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    Changes in the distribution and abundance of invasive species can have far-reaching ecological consequences. Programs to control invaders are common but gauging the effectiveness of such programs using carefully controlled, large-scale field experiments is rare, especially at higher trophic levels. Experimental manipulations coupled with long-term demographic monitoring can reveal the mechanistic underpinnings of interspecific competition among apex predators and suggest mitigation options for invasive species. We used a large-scale before-after control-impact removal experiment to investigate the effects of an invasive competitor, the barred owl (Strix varia), on the population dynamics of an iconic old-forest native species, the northern spotted owl (Strix occidentalis caurina). Removal of barred owls had a strong, positive effect on survival of sympatric spotted owls and a weaker but positive effect on spotted owl dispersal and recruitment. After removals, the estimated mean annual rate of population change for spotted owls stabilized in areas with removals (0.2% decline per year), but continued to decline sharply in areas without removals (12.1% decline per year). The results demonstrated that the most substantial changes in population dynamics of northern spotted owls over the past two decades were associated with the invasion, population expansion, and subsequent removal of barred owls. Our study provides experimental evidence of the demographic consequences of competitive release, where a threatened avian predator was freed from restrictions imposed on its population dynamics with the removal of a competitively dominant invasive species

    Differential cross sections and recoil polarizations for the reaction gamma p -> K+ Sigma0

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    High-statistics measurements of differential cross sections and recoil polarizations for the reaction γp→K+Σ0\gamma p \rightarrow K^+ \Sigma^0 have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (s\sqrt{s}) from 1.69 to 2.84 GeV, with an extensive coverage in the K+K^+ production angle. Independent measurements were made using the K+pπ−K^{+}p\pi^{-}(γ\gamma) and K+pK^{+}p(π−,γ\pi^-, \gamma) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR and LEPS results, while offering better statistical precision and a 300-MeV increase in s\sqrt{s} coverage. Above s≈2.5\sqrt{s} \approx 2.5 GeV, tt- and uu-channel Regge scaling behavior can be seen at forward- and backward-angles, respectively. Our recoil polarization (PΣP_\Sigma) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles we find that PΣP_\Sigma is of the same magnitude but opposite sign as PΛP_\Lambda, in agreement with the static SU(6) quark model prediction of PΣ≈−PΛP_\Sigma \approx -P_\Lambda. This expectation is violated in some mid- and backward-angle kinematic regimes, where PΣP_\Sigma and PΛP_\Lambda are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial wave analyses being performed to search for missing baryon resonances.Comment: 23 pages, 17 figure
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