716 research outputs found

    Non-Unitarity, sterile neutrinos, and Non-Standard neutrino Interactions

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    The simplest Standard Model extension to explain neutrino masses involves the addition of right-handed neutrinos. At some level, this extension will impact neutrino oscillation searches. In this work we explore the differences and similarities between the case in which these neutrinos are kinematically accessible (sterile neutrinos) or not (mixing matrix non-unitarity). We clarify apparent inconsistencies in the present literature when using different parametrizations to describe these effects and recast both limits in the popular neutrino non-standard interaction (NSI) formalism. We find that, in the limit in which sterile oscillations are averaged out at the near detector, their effects at the far detector coincide with non-unitarity at leading order, even in presence of a matter potential. We also summarize the present bounds existing in both limits and compare them with the expected sensitivities of near future facilities taking the DUNE proposal as a benchmark. We conclude that non-unitarity effects are too constrained to impact present or near future neutrino oscillation facilities but that sterile neutrinos can play an important role at long baseline experiments. The role of the near detector is also discussed in detail.Comment: 19 pages, 2 figures: minor changes and references added, version published in JHE

    Estado del arte en procesos de zonificacion

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    Los procesos de partición espacial implican la división de un espacio geográfico en diferentes unidades o zonas según un conjunto específico de criterios. En ámbitos relacionados con las ciencias geoespaciales, la delimitación de estas zonas se realiza por agrupación de otras unidades básicas de área existentes en el espacio de trabajo. En este artículo se ofrece una revisión de los métodos de solución diseñados para este tipo de problemas, comenzando por una introducción a las técnicas heurísticas y modelos matemáticos más utilizados desde los años 60, para finalizar describiendo los recientes algoritmos aplicados a diagramas de Voronoi. También se revisan las aplicaciones en las que se han implementado algunos de estos modelos, quedando patente que son herramientas diseñadas para el tratamiento de problemas específicos, dada la dificultad de diseñar modelos genéricos y versátiles para este tipo de particiones espaciales o zonificacione

    Interactions between financial incentives and health in the early retirement decision

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    We present a theory of the relation between health and retirement that generates testable predictions regarding the interaction of health, wealth and financial incentives in retirement decisions. The theory predicts (i) that wealthier individuals (compared to poorer individuals) are more likely to retire for health reasons (affordability proposition), and (ii) that health problems make older workers more responsive to financial incentives encouraging retirement (reinforcement proposition). We test these predictions using administrative data on older employees in the Dutch healthcare sector for whom we link adverse health events, proxied by unanticipated hospitalizations, to information on retirement decisions and actual incentives from administrative records of the pension funds. Exploiting unexpected health shocks and quasi-exogenous variation in financial incentives for retirement due to reforms, we account for the endogeneity of health and financial incentives. Making use of the actual individual pension rights diminishes downward bias in estimates of the effect of pension incentives. We find support for our affordability and reinforcement propositions. Both propositions require the benefits function to be convex, as in our data. Our theory and empirical findings highlight the importance of assessing financial incentives for their potential reinforcement of health shocks and point to the possibility that differences in responses to financial incentives and health shocks across countries may relate to whether the benefit function is concave or convex

    Tuning metamaterials by using amorphous magnetic microwires

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    In this work, we demonstrate theoretically and experimentally the possibility of tuning the electromagnetic properties of metamaterials with magnetic fields by incorporating amorphous magnetic microwires. The large permeability of these wires at microwave frequencies allows tuning the resonance of the metamaterial by using magnetic fields of the order of tens of Oe. We describe here the physical basis of the interaction between a prototypical magnetic metamaterial with magnetic microwires and electromagnetic waves plus providing detailed calculations and experimental results for the case of an array of Split Ring Resonators with Co-based microwires

    Habitual yogurt consumption and health-related quality of life: A prospective cohort study

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    BACKGROUND: Health-related quality of life (HRQL) is a global indicator of perceived health status, which includes physical and mental domains. Several biological mechanisms might support an association between consumption of yogurt and better HRQL. OBJECTIVE: Our aim was to assess the association between habitual yogurt consumption and HRQL in the general adult population. DESIGN: We conducted a prospective study with 4,445 individuals aged 18 years and older who were recruited in 2008 to 2010 and were followed up to 2012. Habitual yogurt consumption was assessed at baseline with a validated diet history. HRQL was measured with the Physical Composite Summary and the Mental Composite Summary of the Spanish version of the SF-12 Health Survey. The analysis of the association between baseline yogurt consumption and HRQL at 2012 was performed with linear regression and adjusted for the main confounders, including baseline HRQL. RESULTS: Mean follow-up was 3.5 years (standard deviation=0.6 years). Compared with nonconsumers of yogurt, the Physical Composite Summary scores were similar in habitual consumers of ≤6 servings/week (β=.40; P=0.20) and in consumers of ≥1 serving/day (β=.25; P=0.45). A suggestion of tendency toward a lower Mental Composite Summary score was found among daily yogurt consumers (β=-.65; P=0.09; P for trend across categories=0.07). Results were similar among individuals without morbidity, never smokers, and individuals with higher adherence to the Mediterranean diet. CONCLUSIONS: Habitual yogurt consumption did not show an association with improved HRQL

    Thermocapilarity and radiative heat flux oscillations

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    We present a detailled experimental study of the thermocapillary motion of an aniline drop in an stably stratified fluid sytem driven by a laser beam. The thermocapillary motion of drops is the result of the temperature dependence of the interfacial tension. If the surface of the drop is subject to thermal gradients, then non-equilibrium surface tension effects appear, which in some cases can move the drop. We measure some of the velocity induced fields , vorticity, oscilations and intermittency of this complex flow. The source of the no uniformity of the temperature of the surface can be, as is in this experiment, the non uniform heating of the floating drop by a laser beam. In recent years, the thermocapillary movement of bubbles and drops under the influence of laser radiation has received more experimental attention thanks to the improvement in the flow visualization techniques.Peer ReviewedPostprint (published version

    Device Physics of Hybrid Perovskite Solar cells: Theory and Experiment

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    Perovskite solar cells (PSCs) exhibit a series of distinctive features in their optoelectronic response which have a crucial influence on the performance, particularly for long-time response. Here, a survey of recent advances both in device simulation and optoelectronic and photovoltaic responses is provided, with the aim of comprehensively covering recent advances. Device simulations are included with clarifying discussions about the implications of classical drift-diffusion modeling and the inclusion of ionic charged layers near the outer carrier selective contacts. The outcomes of several transient techniques are summarized, along with the discussion of impedance and capacitive responses upon variation of bias voltage and irradiance level. In relation to the capacitive response, a discussion on the J-V curve hysteresis is also included. Although alternative models and explanations are included in the discussion, the review relies upon a key mechanism able to yield most of the rich experimental responses. Particularly for state-of-the-art solar cells exhibiting efficiencies around or exceeding 20%, outer interfaces play a determining role on the PSC's performance. The ionic and electronic kinetics in the vicinity of the interfaces, coupled to surface recombination and carrier extraction mechanisms, should be carefully explored to progress further in performance enhancement

    A de novo complete BRCA1 gene deletion identified in a Spanish woman with early bilateral breast cancer

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    <p>Abstract</p> <p>Background</p> <p>Germline mutations in either of the two tumor-suppressor genes, <it>BRCA1 </it>and <it>BRCA2</it>, account for a significant proportion of hereditary breast and ovarian cancer cases. Most of these mutations consist of deletions, insertions, nonsense mutations, and splice variants, however an increasing number of large genomic rearrangements have been identified in these genes.</p> <p>Methods</p> <p>We analysed <it>BRCA1 </it>and <it>BRCA2 </it>genes by direct sequencing and MLPA. We confirmed the results by an alternative MLPA kit and characterized the <it>BRCA1 </it>deletion by Array CGH.</p> <p>Results</p> <p>We describe the first case of a patient with no strong family history of the disease who developed early-onset bilateral breast cancer with a <it>de novo </it>complete <it>BRCA1 </it>gene deletion in the germinal line. The detected deletion started from the region surrounding the <it>VAT1 </it><it>locus </it>to the beginning of <it>NBR1 </it>gene, including the <it>RND2</it>, Ψ<it>BRCA1</it>, <it>BRCA1 </it>and <it>NBR2 </it>complete genes.</p> <p>Conclusion</p> <p>This finding supports the large genomic rearrangement screening of <it>BRCA </it>genes in young breast cancer patients without family history, as well as in hereditary breast and ovarian cancer families previously tested negative for other variations.</p

    Isokinetic trunk flexion–extension protocol to assess trunk muscle strength and endurance: Reliability, learning effect, and sex differences

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    PurposeThe purpose of this study was to examine the reliability and the learning effect of an isokinetic trunk flexion–extension protocol designed to simultaneously assess trunk muscle strength and endurance. In addition, the effect of the participants' sex on the reliability data was examined.MethodsFifty-seven healthy and physically active young men (n = 28) and women (n = 29) performed the isokinetic protocol 5 times, separated by a week between each of the first 4 sessions and by a month between the last 2 sessions. The protocol consisted of performing 4 trials of 15 maximum flexion–extension concentric exertions at 120°/s (range of trunk motion = 50°). The absolute and relative peak torque and total work were calculated to assess trunk flexion and extension strength. In addition, endurance ratio, modified endurance ratio, fatigue final ratio, recovery ratio, and modified recovery ratio variables were used for the assessment of trunk muscle endurance in both directions.ResultsRegarding the absolute reliability, no relevant changes were found between paired-comparison sessions for most strength and endurance variables, except for total work and relative total work variables in the flexion movement in both sexes. In addition, the typical error of the isokinetic variables was lower than 10% in both males and females, and minimum detectable changes ranged from 7%–20%, with a tendency to be higher in females and in endurance variables. The strength variables showed high intraclass correlation coefficients (ICC; >0.74); however, for the endurance variables only the endurance ratio and the modified endurance ratio obtained moderate to high ICC values (0.57 < ICC < 0.82). In addition, the analysis of the variance reported no significant differences between consecutive pairs of sessions for most variables in both sexes.ConclusionOverall, these findings provide clinicians, trainers, and researchers with a 10-min single-session protocol to perform a reliable muscle strength and endurance evaluation of trunk flexor and extensor muscles, all within the same protocol
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