3,762 research outputs found

    Axion Like Particles and the Inverse Seesaw Mechanism

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    Light pseudoscalars known as axion like particles (ALPs) may be behind physical phenomena like the Universe transparency to ultra-energetic photons, the soft γ\gamma-ray excess from the Coma cluster, and the 3.5 keV line. We explore the connection of these particles with the inverse seesaw (ISS) mechanism for neutrino mass generation. We propose a very restrictive setting where the scalar field hosting the ALP is also responsible for generating the ISS mass scales through its vacuum expectation value on gravity induced nonrenormalizable operators. A discrete gauge symmetry protects the theory from the appearance of overly strong gravitational effects and discrete anomaly cancellation imposes strong constraints on the order of the group. The anomalous U(1)(1) symmetry leading to the ALP is an extended lepton number and the protective discrete symmetry can be always chosen as a subgroup of a combination of the lepton number and the baryon number.Comment: 29pp. v4: published version with erratum. Conclusions unchange

    Screening of heterogeneous surfaces: charge renormalization of Janus particles

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    Nonlinear ionic screening theory for heterogeneously charged spheres is developed in terms of a mode-decomposition of the surface charge. A far-field analysis of the resulting electrostatic potential leads to a natural generalization of charge renormalization from purely monopolar to dipolar, quadropolar, etc., including mode-couplings. Our novel scheme is generally applicable to large classes of surface heterogeneities, and is explicitly applied here to Janus spheres with differently charged upper and lower hemispheres, revealing strong renormalization effects for all multipoles.Comment: 2 figure

    Mammalia, Carnivora, Canidae, Canis latrans (Say, 1823): Actual distribution in Panama

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    This study reports the occurrence of Canis latrans on eastern Panama, including the first report of it presence across the Panama Canal, which expands the known distribution for this species to its southernmost point. The presence of Canis latrans on this region suggests that it is expanding its range Southwards by using deforested areas and areas of cattle ranching alongside the Panamerican Highway. This highway crosses the isthmus up to the Darien Province

    Genetic and Molecular Factors in Drug-Induced Liver Injury: A Review

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    The diagnosis of drug-induced liver injury (DILI) is challenging and based on complex diagnostic criteria. DILI falls into two main categories i) intrinsic 'dose-dependent' Type A reactions ii) 'idiosyncratic' or Type B reactions (which are usually not predictable). Idiosyncratic reactions can be immunoallergic (hypersensitivity), or metabolic, although overlap between categories can occur. The aim of this review is to summarise the general view of underlying mechanisms in DILI and to highlight individual risk factors for developing hepatotoxicity. Polymorphisms of bioactivation/ toxification pathways through CYP450 enzymes (Phase I), detoxification reactions (Phase II) and excretion/transport (Phase III) are explored together with immunological factors that might determine DILI. The importance of establishing a multidisciplinary and multi-centric network to promote the understanding and research in hepatotoxicity is underlined. Challenges such as genetic analyses for association studies and whole genome studies, pharmacogenetic testing and future approaches to study DILI are considered. Knowledge regarding these operational mechanisms could provide further insight for the prospective identification of susceptible patients at risk of developing drug-induced hepatotoxicity.

    High temperature behavior of Sr-doped layered cobaltites Y(Ba1-xSrx)Co2O5.5: phase stability and structural properties

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    In this article we present a neutron diffraction in-situ study of the thermal evolution and high-temperature structure of layered cobaltites Y(Ba, Sr)Co2 O5+{\delta}. Neutron thermodiffractograms and magnetic susceptibility measurements are reported in the temperature range 20 K <= T <= 570 K, as well as high resolution neutron diffraction experiments at selected temperatures. Starting from the as-synthesized samples with {\delta} ~ 0.5, we show that the room temperature phases remain stable up to 550 K, where they start loosing oxygen and transform to a vacancy-disordered "112" structure with tetragonal symmetry. Our results also show how the so-called "122" structure can be stabilized at high temperature (around 450 K) in a sample in which the addition of Sr at the Ba site had suppressed its formation. In addition, we present the structural and magnetic properties of the resulting samples with a new oxygen content {\delta} ~ 0.25 in the temperature range 20 K <= T <= 300 K

    Testing a eustress–distress emotion regulation model in British and Spanish front-line employees

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    Studies suggest that suppressing emotions required by occupational roles (i.e., surface acting [SA]) can lead to employees’ emotional exhaustion. In contrast, trying to experience the emotions required by the role (i.e., deep acting [DA]) appears to be a less harmful strategy for the employee. However, problems with 1 of the mainstream measures of DA call for a reexamination of the construct’s operationalization and a clarification of its consequences. Furthermore, an integrated model explaining the differential outcomes of the 2 main emotion regulation (ER) strategies (SA and DA) is also required. Building on eustress–distress literature, it was hypothesized that cognitive reappraisal (a suggested operationalization of DA) would be associated with perception of thriving customer interactions, eliciting the eustress response (i.e., increased efficacy and commitment). It was also expected that suppression would be associated with perception of draining customer interactions, emotional exhaustion, and turnover intentions. Importantly, in line with the eustress–distress model, no cross-relationships between the eustress and distress route were hypothesized. A cross-national study comprised theme park employees from Spain (N=208) and the United Kingdom (N=204) and multigroup confirmatory factor analysis was used. Hypotheses were supported therefore the eustress–distress model offers a plausible explanation of the work-related ER outcomes. As an ER strategy, cognitive reappraisal may promote perceptions of thriving customer interactions that in turn generates opportunities to develop valued personal resources and organizationally desirable attitudes. Organizations should invest in individually based interventions to assist employees in interpreting customer demands in less harming ways

    Individually-rational collective choice

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    There is a collection of exogenously given socially-feasible sets, and, for each one of them, each individual in a group chooses from an individually-feasible set. The fact that the product of the individually-feasible sets is larger than the socially-feasible set notwithstanding, there arises no conflict between individual choices. Assuming that individual preferences are random, I characterize rationalizable collective choices

    High-pressure synthesis of rock salt LiMeO2-ZnO (Me = Fe3+, Ti3+) solid solutions

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    Metastable LiMeO2-ZnO (Me = Fe3+, Ti3+) solid solutions with rock salt crystal structure have been synthesized by solid state reaction of ZnO with LiMeO2 complex oxides at 7.7 GPa and 1350-1450 K. Structure, phase composition, thermal stability and thermal expansion of the recovered samples have been studied by X-ray diffraction with synchrotron radiation. At ambient pressure rock salt LiMeO2-ZnO solid solutions are kinetically stable up to 670-800 K depending on the composition.Comment: 11 pages, 3 figures, 1 tabl
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