2,483 research outputs found

    Desarrollo del comportamiento proambiental en los individuos y sus determinantes

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    Este artículo analiza el comportamiento proambiental en individuos ofreciendo una clasificación del comportamiento según la diversidad/ intensidad de las acciones ambientales emprendidas, y explicando el desarrollo del comportamiento pro-ambiental y algunos de los factores que lo determinan. Mediante análisis cluster y modelos de ecuaciones estructurales, aplicado al Estudio 2837 del CIS, se obtiene una clasificación en cinco grupos de individuos que pone de manifiesto cómo se desarrolla el comportamiento pro-ambiental, desde niveles con poca intensidad en acciones medioambientales muy concretas (como el reciclado) hasta niveles de mayor implicación proambiental en un buen número de acciones proambientales. The aim of this study is to learn more about pro-environmental conduct in individuals, providing classification in levels of conduct according to diversity/intensity of environmental actions, showing how proenvironmental conduct develops in people and identifying the factors that determine such conduct. The application of cluster analysis and structural equation models to CIS Study 2837 classifies individuals with different degrees of environmental involvement into five groups, showing how pro-environmental conduct develops in people, from specific activities (such as recycling) performed with reduced intensity to greater and more intense pro-environmental involvement

    How is environmental proactivity accomplished? Drivers and barriers in firms' pro-environmental change process

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    The contaminating effects of economic activity and the scarcity of natural resources has led firms to a situation in which corporate strategy has been compromised by environmental issues. The objective of this paper is to analyse some of the factors determining the pro-environmental change process by considering the drivers encouraging firms to progress in environmental protection and the barriers that curb this progress. Using a structural equation model implemented on a sample of 303 firms, our results confirm a direct and positive effect of stakeholder pressure and of the expectations of obtaining competitive advantages from the pro-environmental change process. The results also confirmed the indirect effect of stakeholder pressure on pro-environmental change through managers'' expectations of obtaining competitive advantages, which play a mediating role in the firm''s response. Although managers interpret the barriers we have studied as obstacles to adopting environmental protection measures, they do not prevent any firm from reaching advanced levels of pro-environmental change

    Análisis al Sistema Interamericano de Derechos Humanos a la luz de sus estándares internacionales sobre el acceso a la justicia

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    Los regímenes internacionales se han dado a la tarea de explicar el alcance que tienen los derechos humanos a través de los estándares internacionales. Particularmente, el Sistema Interamericano de Derechos Humanos, ha establecido criterios de gran relevancia en sus resoluciones que contienen estándares sobre el acceso a la justicia. Sin embargo, el cúmulo de peticiones recibidas aunado a la falta de recursos para darles trámite oportuno, la onerosidad del procedimiento y la falta de implementación de las decisiones de sus órganos, son un problema para su accesibilidad al grado tal que, en muchas ocasiones, el Sistema Interamericano no es el reflejo de sencillez y rapidez que marcan sus propios estándares. Ante esta panorámica, en este trabajo se realiza un análisis al diseño del régimen interamericano a la luz sus los estándares internacionales que ha establecido en torno al acceso a la justicia. La idea es explicar cuáles son los principales problemas que pugnan con sus estándares sobre el acceso a la justicia y formular una propuesta para contribuir a mejorar su estado actual

    Analysis of energy poverty intensity from the perspective of the regional administration: Empirical evidence from households in southern Europe

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    The current economic situation has increased the number of households in Europe experiencing restrictions and/or limitations of affordability of energy services, demonstrating the urgent need to intervene in those extreme cases in which households suffer the daily consequences of what is internationally defined as energy poverty. In such a context, this paper presents the results obtained in a case study characterising a sample of 615 households with demonstrated energy poverty in the region of Aragón (Spain). In parallel, the intensity of energy poverty in the studied cases is examined by measuring the percentage of energy expenditures with respect to income in the households that suffer it, and a descriptive analysis of the main determinants of energy poverty in the homes studied is presented as well as the policy implication at regional level

    Effects of water inlet configuration in a service reservoir applying CFD modelling

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    This study investigated the state of a service reservoir of a drinking water distribution network. Numerical simulation was applied to establish its flow pattern, mixing conditions, and free residual chlorine decay. The influence of the change in the water inlet configuration on these characteristics was evaluated. Four scenarios were established with different water level and flow rate as the differences between the first three scenarios. The fourth scenario was evaluated to assess the influence of the inlet configuration, momentum flow and water level on hydrodynamic conditions within the service reservoir. The distribution of four nozzles of 152.4 mm diameter was identified as a viable measure to preserve the water quality in this type of hydraulic structures

    Energy vulnerability composite index in social housing, from a household energy poverty perspective

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    In Europe, the proportion of social housing is high, and such houses tend to be inhabited by below average-income households, which are particularly vulnerable to energy poverty. This article proposes a new methodological approach for defining an index for household energy vulnerability assessment. This method can be used to improve the management of social housing. After establishing a heuristic framework for household energy poverty-which stems from different causes such as income, the characteristics of the residence, energy installations, and the energy-consumption habits of household members-multi-criteria analytical methods, based on the aggregation of indicators which reveal the conditions leading to energy poverty, have been applied, and effective means of intervention are proposed. The method is also applied to a sample of social houses and thus validated as a useful tool in decision-making processes which concern the management of social housing from a household energy-poverty perspective

    HAT-P-11b: A Super-Neptune Planet Transiting a Bright K Star in the Kepler Field

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    We report on the discovery of HAT-P-11b, the smallest radius transiting extrasolar planet (TEP) discovered from the ground, and the first hot Neptune discovered to date by transit searches. HAT-P-11b orbits the bright (V=9.587) and metal rich ([Fe=H] = +0.31 +/- 0.05) K4 dwarf star GSC 03561-02092 with P = 4.8878162 +/- 0.0000071 days and produces a transit signal with depth of 4.2 mmag. We present a global analysis of the available photometric and radial-velocity data that result in stellar and planetary parameters, with simultaneous treatment of systematic variations. The planet, like its near-twin GJ 436b, is somewhat larger than Neptune (17Mearth, 3.8Rearth) both in mass Mp = 0.081 +/- 0.009 MJ (25.8 +/- 2.9 Mearth) and radius Rp = 0.422 +/- 0.014 RJ (4.73 +/- 0.16 Rearth). HAT-P-11b orbits in an eccentric orbit with e = 0.198 +/- 0.046 and omega = 355.2 +/- 17.3, causing a reflex motion of its parent star with amplitude 11.6 +/- 1.2 m/s, a challenging detection due to the high level of chromospheric activity of the parent star. Our ephemeris for the transit events is Tc = 2454605.89132 +/- 0.00032 (BJD), with duration 0.0957 +/- 0.0012 d, and secondary eclipse epoch of 2454608.96 +/- 0.15 d (BJD). The basic stellar parameters of the host star are M* = 0.809+0.020-0.027 Msun, R* = 0.752 +/- 0.021 Rsun and Teff = 4780 +/- 50 K. Importantly, HAT-P-11 will lie on one of the detectors of the forthcoming Kepler mission. We discuss an interesting constraint on the eccentricity of the system by the transit light curve and stellar parameters. We also present a blend analysis, that for the first time treats the case of a blended transiting hot Jupiter mimicing a transiting hot Neptune, and proves that HAT-P-11b is not such a blend.Comment: Accepted for publication in ApJ, 24 pages, 14 figures, 6 tables. All RV data presented in this versio

    Neutron radiobiology studies with a pure cold neutron beam

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    Data on the radiobiological effects of thermal neutrons are usually obtained from irradiations in a mixed field of neutrons of different energies and gamma rays or from conversion of proton data with similar energies to those created in the neutron capture on nitrogen. Experimental data from irradiations in a pure thermal or cold neutron beam can help to find new values for neutron relative biological effectiveness (RBE) factors, which are useful for BNCT (Boron Neutron Capture Therapy) and radiation protection applications. We present a new experimental setup for radiobiological studies at a cold neutron beam at Institut Laue-Langevin, a beam without fast neutron component and almost no gamma ray contribution. After the irradiation, survival assays are performed to obtain the survival curves. Finally, comparing with a reference photon irradiation, the thermal neutron RBE factors can be calculated. The methodology is outlined at the example of A375 melanoma cells for which new radiobiological data were obtained.We acknowledge financial support for this work from the Fundación Científica de la Asociación Española Contra el Cáncer (AECC) under grant PS16163811PORR, Junta de Andalucía (Andalusian Regional Government), under contract P11-FQM-8229, Spanish MINECO and FEDER funds under contract FIS2015-69941-C2-1-P, the grant agreement ILL-UGR and the founders of the University of Granada Chair Neutrons for Medicine: Spanish Fundación ACS and Capitán Antonio. M.P. acknowledges a grant under the program Becas de Iniciación a la Investigación from the Universidad de Granada (Plan Propio de Investigación). The open access fee was covered by FILL2030, a European Union project within the European Commission’s Horizon 2020 Research and Innovation programme under grant agreement N°731096

    Using the MitoB method to assess levels of reactive oxygen species in ecological studies of oxidative stress

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    In recent years evolutionary ecologists have become increasingly interested in the effects of reactive oxygen species (ROS) on the life-histories of animals. ROS levels have mostly been inferred indirectly due to the limitations of estimating ROS from in vitro methods. However, measuring ROS (hydrogen peroxide, H2O2) content in vivo is now possible using the MitoB probe. Here, we extend and refine the MitoB method to make it suitable for ecological studies of oxidative stress using the brown trout Salmo trutta as model. The MitoB method allows an evaluation of H2O2 levels in living organisms over a timescale from hours to days. The method is flexible with regard to the duration of exposure and initial concentration of the MitoB probe, and there is no transfer of the MitoB probe between fish. H2O2 levels were consistent across subsamples of the same liver but differed between muscle subsamples and between tissues of the same animal. The MitoB method provides a convenient method for measuring ROS levels in living animals over a significant period of time. Given its wide range of possible applications, it opens the opportunity to study the role of ROS in mediating life history trade-offs in ecological settings

    A Keck HIRES Doppler Search for Planets Orbiting Metal-Poor Dwarfs. II. On the Frequency of Giant Planets in the Metal-Poor Regime

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    We present an analysis of three years of precision radial velocity measurements of 160 metal-poor stars observed with HIRES on the Keck 1 telescope. We report on variability and long-term velocity trends for each star in our sample. We identify several long-term, low-amplitude radial-velocity variables worthy of follow-up with direct imaging techniques. We place lower limits on the detectable companion mass as a function of orbital period. Our survey would have detected, with a 99.5% confidence level, over 95% of all companions on low-eccentricity orbits with velocity semi-amplitude K > 100 m/s, or M_p*sin(i) > 3.0 M_JUP*(P/yr)^(1/3), for orbital periods P< 3 yr. None of the stars in our sample exhibits radial-velocity variations compatible with the presence of Jovian planets with periods shorter than the survey duration. The resulting average frequency of gas giants orbiting metal-poor dwarfs with -2.0 < [Fe/H] < -0.6 is f_p<0.67% (at the 1-sigma confidence level). We examine the implications of this null result in the context of the observed correlation between the rate of occurrence of giant planets and the metallicity of their main-sequence solar-type stellar hosts. By combining our dataset with the Fischer & Valenti (2005) uniform sample, we confirm that the likelihood of a star to harbor a planet more massive than Jupiter within 2 AU is a steeply rising function of the host's metallicity. However, the data for stars with -1.0 < [Fe/H] < 0.0 are compatible, in a statistical sense, with a constant occurrence rate f_p~1%. Our results can usefully inform theoretical studies of the process of giant planet formation across two orders of magnitude in metallicity.Comment: 59 pages, 7 tables, 8 figures. Accepted for publication in the Astrophysical Journa
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