3,445 research outputs found

    Diffusion dynamics on multiplex networks

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    We study the time scales associated to diffusion processes that take place on multiplex networks, i.e. on a set of networks linked through interconnected layers. To this end, we propose the construction of a supra-Laplacian matrix, which consists of a dimensional lifting of the Laplacian matrix of each layer of the multiplex network. We use perturbative analysis to reveal analytically the structure of eigenvectors and eigenvalues of the complete network in terms of the spectral properties of the individual layers. The spectrum of the supra-Laplacian allows us to understand the physics of diffusion-like processes on top of multiplex networks.Comment: 6 Pages including supplemental material. To appear in Physical Review Letter

    Malnutrition as cause and consequence of sensory distorsiones

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    La malnutrición es una enfermedad provocada por un exceso o defecto en el consumo o aprovechamiento de los nutrientes. Habitualmente, se utiliza este término para referirse a la desnutrición, es decir, a un trastorno derivado del déficit de algún macro y o micronutrientes. Las alteraciones quimiosensoriales pueden reducir de forma importante la alimentación en el individuo, por lo que es importante verificar que el aporte de nutrientes y, de forma concreta, de algunos micronutrientes, sea suficiente, ya que alguno de ellos, como el zinc, desempeñan un papel primordial en las alteraciones del gusto y del olfato. Además, el paciente malnutrido o con una alimentación que excluya gran número de alimentos, tiene mayor riesgo de presentar déficits de dichos micronutrientes. Diversas enfermedades, tanto agudas como crónicas, se asocian a alteraciones de la percepción sensorial, y pueden llegar a afectar a más del 50% de las personas mayores de 65 años. Los efectos provocados por los fármacos y algunos tratamientos como la quimioterapia y la radioterapia, juegan también un papel muy importante en la distorsión sensorial y en la incidencia de malnutriciónMalnutrition is a pathological condition caused by an excess or deficiency in the consumption or the use of the nutrients. Usually this term refers to a lack of adequate nourishment, a disorder resulting from a deficiency of some macro and/or micronutrients. Chemo-sensory alterations can significantly reduce food choice and intake, so it is very important to verify that the supply of nutrients and specifically of some micronutrients are sufficient. Some of them, such as “zinc”, play a very important role in alterations in the sense of taste and smell. In addition malnutrition patients or a poorly-balanced diet or faulty utilization of foods have increased the risk of deficiencies in these micronutrients. Several types of diseases, both acute and chronic ones, are associated with sensory perception and can affect more than 50% of people over 65 years old. The effects caused by drugs and some treatments such as chemotherapy and radiation therapy play an important role in sensory distortion and the incidence of malnutritio

    Assessing the demand for hydrological drought insurance in irrigated agriculture

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    Concerns about hydrological drought risk and irrigation water supply reliability have grown in recent years due to the increasing demand for water for irrigation and other uses, and the decline in water availability due to climate change. Hydrological drought insurance hedging against water supply gaps can be a key instrument for adapting irrigated agriculture to this new scenario, since it improves the resilience of the irrigation sector, which is having to cope with increasing uncertainty and vulnerability. The objective of this paper is to assess farmers’ willingness to pay (WTP) for index-based hydrological drought insurance under different policy designs, considering several different amounts of insured capital, insurance deductibles, and contract terms. To that end, it uses a discrete choice experiment as the valuation method and the Sector BXII irrigation district (southern Spain) as a case study. The results show that farmers would be willing to pay for the proposed hydrological drought insurance, stating a higher preference for policy designs with lower amounts of insured capital, lower deductibles, and shorter contract terms. Moreover, the results also show the existence of heterogeneity among farmers’ preferences, depending on their socio-economic characteristics. Finally, we compare the distribution of farmers’ WTP for different policy design options of the proposed insurance with the commercial premium estimated using actuarial analysis. The comparison confirms that only the options with lower levels of insured capital present a mean WTP below the commercial premium, while the rest of the policy design options would need to be subsidized like other agricultural insurance schemes to make them attractive to most farmers

    Permeabilidad de gases en membranas de zeolita ZSM-5

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    El trabajo incluido en el presente articulo tiene como objetivo analizar la influencia de la deposición de zeolita ZSM-5 en un tubo de alumina sobre la velocidad de transferencia de materia de distintos gases con el fin de analizar la capacidad de separación. Se ha evaluado la influencia de la presencia de zeolita, así como del caudal de gas alimentado y la temperatura a la que se desarrolla el proceso deseparación

    Responsabilidad social en las organizaciones públicas: la omisión al cumplimiento de responsabilidades de los servidores públicos en México, el caso de los legisladores.

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    Este artículo plantea a través de una investigación teórica, lo que acontece en la actividad legislativa de los diputados en México, quienes en el ejercicio de su función, pasan a la inactividad legislativa, es decir, dejan de actuar como se espera, de acuerdo con la responsabilidad que la ley les atribuye. Nos referimos a la comisión de responsabilidad por omisión. Los diputados, de acuerdo con sus responsabilidades debe crear leyes, pero ellos no las realizan o lo hacen de manera insuficiente, faltando con esto a sus responsabilidades como servidores públicos. El artículo inicia planteando cuál es el deber ser del servidor dentro del servicio público, posteriormente acerca al lector a un marco teórico del servicio público en México, así como la relación de estos conceptos con la corrupción, término que incluye la responsabilidad política, y el ejercicio de la función legislativa como pauta de acción de los legisladores. La incidencia en actos como la omisión de los servidores públicos, se ha discutido desde la perspectiva jurídica, sin embargo, no ha sido suficiente para subsanar la falta de legislación, dentro de las responsabilidades de los diputados esta la de legislar, es decir, crear leyes, cuando los legisladores incumplen con esta obligación, dejan en desprotección a sectores sociales por falta de leyes que los protejan o los regulen, con esto se provocan muchas de las lagunas legislativas que se tiene en el marco jurídico nacional, lo cual se origina en esta falta legislativa llamada omisión

    Administración pública y gobernanza: el papel de la gestión de la ética en las organizaciones públicas

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    El presente trabajo parte de la importancia que tiene la administración pública en la conducción del progreso social como componente del sistema político y su estrecha relación con la ética para cumplir sus cometidos de eficiencia, eficacia y legitimidad. El marco teórico fundamental se basa en la concepción que hace Uvalle en sus diversos escritos sobre la importancia de la administración pública desde sus primeros escritos, hasta recuperar en estudios recientes el concepto de gobernanza y su vinculación con valores actuales del servicio público tales como, ética, rendición de cuentas, transparencia y profesionalización. La hipótesis central del trabajo consiste en afirmar que existe una estrecha relación entre la ética y una administración pública de calidad que es uno de los atributos del modelo de gobernanza. Así, no puede concebirse un gobierno, abierto, transparente y ético, que no se convierta en un modelo democrático en el que el espacio público y la participación constituyen su base de legitimación

    Arc Stability Characterization of Double Coated Electrodes for Hardfacing

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    The aim of this work is to establish the influence of the relative position of the alloy charge C-Cr-Mn in the structure of the coating of rutile electrodes for hardfacing, on the operational behavior (arc stability). For this, three variants of electrodes with similar chemical composition are elaborated in the metallic core and the coating, differentiating only in the relative position that occupies the alloy charge (C-Cr-Mn) in the structure of the coating: internal, external and homogeneous. For the development of the research, a completely random design is used. The operative characterization of the electrodes is performed in terms of the arc stability. In conclusion, it can be seen that the position of the alloy load influences the operation behavior (stability of the arc). The variant of internal alloy charge in the coating presents the better arc stability performance

    Comparing multiple criteria for species identification in two recently diverged seabirds

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    Correct species identification is a crucial issue in systematics with key implications for prioritising conservation effort. However, it can be particularly challenging in recently diverged species due to their strong similarity and relatedness. In such cases, species identification requires multiple and integrative approaches. In this study we used multiple criteria, namely plumage colouration, biometric measurements, geometric morphometrics, stable isotopes analysis (SIA) and genetics (mtDNA), to identify the species of 107 bycatch birds from two closely related seabird species, the Balearic (Puffinus mauretanicus) and Yelkouan (P. yelkouan) shearwaters. Biometric measurements, stable isotopes and genetic data produced two stable clusters of bycatch birds matching the two study species, as indicated by reference birds of known origin. Geometric morphometrics was excluded as a species identification criterion since the two clusters were not stable. The combination of plumage colouration, linear biometrics, stable isotope and genetic criteria was crucial to infer the species of 103 of the bycatch specimens. In the present study, particularly SIA emerged as a powerful criterion for species identification, but temporal stability of the isotopic values is critical for this purpose. Indeed, we found some variability in stable isotope values over the years within each species, but species differences explained most of the variance in the isotopic data. Yet this result pinpoints the importance of examining sources of variability in the isotopic data in a case-by-case basis prior to the cross-application of the SIA approach to other species. Our findings illustrate how the integration of several methodological approaches can help to correctly identify individuals from recently diverged species, as each criterion measures different biological phenomena and species divergence is not expressed simultaneously in all biological traits

    Gas-liquid interfacial area in oxygen absorption into oil-in-water emulsions

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    Present work includes an exhaustive study about gas-liquid interfacial area between gas phase and liquid heterogeneous medium generated in an airlift bioreactor. The model system studied is composed by water, methyl ricinoleate and Tween 80, since it is the base of the medium used for the production of γ-decalactone through the biotransformation of ricinoleic acid, by the yeast Yarrowia lipolytica. Experimental results allow describing the hydrodynamic behavior of the gas phase into the biphasic medium. In the oil-in-water system used, a decrease of the gas-liquid interfacial area with the oil concentration increase was found, due to the redistribution of surfactant between interface and bulk phases
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