869 research outputs found

    Saharan dust deposition may affect phytoplankton growth in the mediterranean sea at ecological time scales

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    The surface waters of the Mediterranean Sea are extremely poor in the nutrients necessary for plankton growth. At the same time, the Mediterranean Sea borders with the largest and most active desert areas in the world and the atmosphere over the basin is subject to frequent injections of mineral dust particles. We describe statistical correlations between dust deposition over the Mediterranean Sea and surface chlorophyll concentrations at ecological time scales. Aerosol deposition of Saharan origin may explain 1 to 10% (average 5%) of seasonally detrended chlorophyll variability in the low nutrient-low chlorophyll Mediterranean. Most of the statistically significant correlations are positive with main effects in spring over the Eastern and Central Mediterranean, conforming to a view of dust events fueling needed nutrients to the planktonic community. Some areas show negative effects of dust deposition on chlorophyll, coinciding with regions under a large influence of aerosols from European origin. The influence of dust deposition on chlorophyll dynamics may become larger in future scenarios of increased aridity and shallowing of the mixed layerPostprint (published version

    El Parlament aprova la Llei de l’Institut Català de la Salut

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    Activitat Parlamentària dedica un comentari en profunditat de les lleis aprovades durant el segon període de sessions, que tenen especial rellevància, sigui per raó de la matèria, de l’abast o de les novetats que introdueix. Cada comentari està elaborat per una persona coneixedora de la matèria i del procés d’elaboració de la llei

    Is the utilization of methane gas, the sollution of air pollution in difuse sectors?. The case of port of Castellón

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    Within an scenario of highly sensitivity on environmental questions, followed by an international regulation body, that is restricting the emission levels from ships in ports with the future possibilit y of more stringent local regulations; the challenge for the world’s fleet are not only technical but economic and logistical. From one side, there are different technical alternatives affording to accomplish the nowadays international regulations. Even avoiding on board modifications, the owner can decide to use low sulphur content fuels, together with slight changes in engines to reduce the levels of nitrogen oxides. But the question posed in this paper is how to support the decision to use high quality oil derivatives, because environment questions, but with a favorable economic balance. That superior cost will be translated in a higher transport chain cost. Additionally regarding coastal navigation, it is possible in the future that some new regulations could penalize elevated rates of CO2 emissions, not yet considered by MARPOL convention. This paper will analyze the availability of the use of methane as ideal fuel to get compliment of the nowa days and even future, local and international regulations of CO2 and NOX, regarding the fuel derivatives and no emissions of sulphur oxides and ashes.Postprint (published version

    Transcriptome Analysis in Renal Transplant Biopsies Not Fulfilling Rejection Criteria

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    The clinical significance of renal transplant biopsies displaying borderline changes suspicious for T-cell mediated rejection (TCMR) or interstitial fibrosis and tubular atrophy (IFTA) with interstitial inflammation has not been well defined. Molecular profiling to evaluate renal transplant biopsies using microarrays has been shown to be an objective measurement that adds precision to conventional histology. We review the contribution of transcriptomic analysis in surveillance and indication biopsies with borderline changes and IFTA associated with variable degrees of inflammation. Transcriptome analysis applied to biopsies with borderline changes allows to distinguish patients with rejection from those in whom mild inflammation mainly represents a response to injury. Biopsies with IFTA and inflammation occurring in unscarred tissue display a molecular pattern similar to TCMR while biopsies with IFTA and inflammation in scarred tissue, apart from T-cell activation, also express B cell, immunoglobulin and mast cell-related genes. Additionally, patients at risk for IFTA progression can be identified by genes mainly reflecting fibroblast dysregulation and immune activation. At present, it is not well established whether the expression of rejection gene transcripts in patients with fibrosis and inflammation is the consequence of an alloimmune response, tissue damage or a combination of both

    A comparison of generalized multinomial logit, random parameters logit, wtp-space and latent class models to studying consumers' preferences for animal welfare

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    The European societies are requiring that animals to be raised as closely as possible to their natural conditions. The growing concerns about animal welfare is resulting in continuous modifications of regulations and policies that led to ban of a number of intensive farming methods. The European authorities consider the pig welfare as a priority issue. They are studying to ban surgical pig castration by 2018, which may seriously affect markets and consumers due to boar tainted-meat. This study analysed consumers’ preferences and acceptance regarding an alternative to castration of high-level boar-taint frankfurter sausages. Non-hypothetical discrete choice experiments was applied by creating a real shopping scenario before and after tasting the products. Data were collected for a sample of 150 consumers from the metropolitan area of Madrid, Spain. Different modelling approaches (Generalized Multinomial Logit-GMNL, Random Parameters Logit-RPL, WTP-space and Latent Class-LC models) were applied to figure out which model have the best goodness of fit. Results showed the appropriateness of the proposed alternative by using a new flavour as a masking strategy. When consumers tasted the products, they showed their willingness to pay a premium for this flavour. The WTP space model showed the best goodness of fit in terms of likelihood, Akaike information criterion and McFadden Pseudo R2. Furthermore, the degree of randomness identified by the scale parameter is also estimated. Uncertainty in selection decreased significantly after the sensory experiencePostprint (published version

    ¿Puede la intregación de un PLE en una plataforma de e-portfolio mejorar las competencias genéricas?

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    The study analyzes the improvement in generic competences through e-portfolio/PLE platform and didactic planning. The new version of the platform, Digital Folder, contains utilities for students and teachers and some PLE components that help the learning process through e-portfolios. Didactic planning is compared for students from the University of Vic and the University of Barcelona, with a total of 61 participants. A questionnaire has been applied for measuring the use of functions and how much these functions aid in the improvement of the generic competences (reflection, planning and selection of information). The results confirm that the most helpful functions for students are: the Schedule, the Academic tasks, the Teacher’s portfolio and Dialogue with the teacher. However, the implication of these functions in the improvement of the competences depends on didactic planning overall for reflection on learning.El estudio analiza la mejora de las competencias genéricas a través de una plataforma de e-portfolio / PLE y una planificación didáctica. La nueva versión de la Plataforma Carpeta Digital contiene herramientas para estudiantes, profesores y algunos componentes PLE que ayudan al proceso de aprendizaje a través de portfolios electrónicos. Se compara la planificación didáctica con los alumnos de la Universidad de Vic y la Universidad de Barcelona con un total de 61 participantes. Se ha aplicado un cuestionario para medir el uso de las funciones y en qué medida estas funciones ayudan a mejorar las competencias genéricas (reflexión, planificación y selección de la información). Los resultados confirman que las funciones más útiles para los estudiantes son: el horario, las tareas académicas, el portfolio de los maestros y el diálogo con los mismos. Sin embargo, la implicación de estas funciones en la mejora de las competencias depende de la planificación didáctica, en general para la reflexión del aprendizaje.Ministerio de Economía y Competitividad (Government of Spain

    Coherence and anticoherence resonance tunned by noise

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    We present numerical evidence and a theoretical analysis of the appearance of anticoherence resonance induced by noise, not predicted in former analysis of coherence resonance. We have found that this phenomenon occurs for very small values of the intensity of the noise acting on an excitable system, and we claim that this is a universal signature of a nonmonotonous relaxational behavior near its oscillatory regime. Moreover, we demonstrate that this new phenomenon is totally compatible with the standard situation of coherence resonance appearing at intermediate values of noise intensity

    Genetic evidences of natural selection

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    La selección natural es un proceso biológico que constituye uno de los principales motores de cambio evolutivo, y el origen de las adaptaciones fenotípicas. La selección que actúa sobre una determinada población se puede detectar ecológicamente cuantificando a nivel intrapoblacional la relación existente entre el fenotipo de los individuos y su éxito reproductivo diferencial. Sin embargo, detectar la actuación de la selección pretérita es imposible usando una aproximación exclusivamente ecológica. Para afrontar este problema, durante los últimos 40 años se han desarrollado una serie de métodos moleculares que infieren la actuación de la selección. Un primer grupo de pruebas usa como modelo nulo la teoría cuasi neutral de la evolución molecular, y asumen que ha ocurrido selección cuando el resultado difiere significativamente de lo esperable según evolución neutral. Algunos tests, como por ejemplo la D de Tajima, la relación dN/dS , o las pruebas de MK o HKA, pueden determinar incluso el tipo de selección operante. Sin embargo, raramente pueden cuantificar la intensidad de selección. Este inconveniente es exitosamente superado por el análisis de la selección basada en Campos Aleatorios de Poisson (PRF). Un segundo grupo de pruebas usa como método para inferir la acción pretérita de la selección natural la comparación entre la cantidad de diferenciación genética en caracteres cuantitativos (QST) y la cantidad de diferenciación genética neutra (FST). Finalmente, unos de los más recientes y prometedores métodos que se están desarrollando para el estudio de la selección natural está relacionado con el avance tan espectacular que está registrando en la actualidad la genómica. Aún estamos lejos de saber la verdadera utilidad de esta herramienta para el estudio de la selección natural en poblaciones naturales, pero el pronóstico es bastante esperanzador.Natural selection is one of the main factors driving the evolutionary process and the only one leading to adaptations. Selection acting on a population can be detected by quantifying the relationship between individual phenotype and relative fitness. However, detecting the effect of past selection is not possible by only using an ecological approach. To cope with this issue, several molecular evolutionary genetics methods have been developed during the last 40 years. A first group of tests use the quasi neutral theory of molecular evolution as null model, and assume the occurrence of selection when the observed outcome significantly departs from the expectations under neutral evolution. Some tests, such as Tajima’s D, dN/dS ratio, MK test or HKA test, can determine the kind of selection acting on populations, but are unable to quantify its intensity. The analysis of selection based on Poisson Random Fields (PRF) overcomes this caveat. A second group of analyses infer selection by comparing the amount of genetic variation in quantitative traits (QST) against the amount of neutral genetic variation (FST). Lastly, one of the most recent and promising methods to explore natural selection is related with the superb advance in genomics. Although we are still far from fully appreciate the importance of this tool, we believe that the use of the genomics will produce a qualitative enhancement in our understanding of the importance of natural selection in the wild
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