25,021 research outputs found

    Lagrangian transport in a microtidal coastal area: the Bay of Palma, island of Mallorca, Spain

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    Coastal transport in the Bay of Palma, a small region in the island of Mallorca, Spain, is characterized in terms of Lagrangian descriptors. The data sets used for this study are the output for two months (one in autumn and one in summer) of a high resolution numerical model, ROMS, forced atmospherically and with a spatial resolution of 300 m. The two months were selected because its different wind regime, which is the main driver of the sea dynamics in this area. Finite-size Lyapunov Exponents (FSLEs) were used to locate semi-persistent Lagrangian coherent structures (LCS) and to understand the different flow regimes in the Bay. The different wind directions and regularity in the two months have a clear impact on the surface Bay dynamics, whereas only topographic features appear clearly in the bottom structures. The fluid interchange between the Bay and the open ocean was tudied by computing particle trajectories and Residence Times (RT) maps. The escape rate of particles out of the Bay is qualitatively different, with a 32% more of escape rate of particles to the ocean in October than in July, owing to the different geometric characteristics of the flow. We show that LCSs separate regions with different transport properties by displaying spatial distributions of residence times on synoptic Lagrangian maps together with the location of the LCSs. Correlations between the time-dependent behavior of FSLE and RT are also investigated, showing a negative dependence when the stirring characterized by FSLE values moves particles in the direction of escape

    How are Spanish academics coping with changes? Responses from a life histories research.

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    Podeu consultar la versió en català a: http://diposit.ub.edu/dspace/handle/2445/20983[eng] This report is part of the research project, The effects of social changes in work and professional life of Spanish academics, partially financed by the Spanish Ministry of Science and Innovation (SEJ2006-01876), that has explored change in legislation, organisation, research schemes and so on, in the last thirty years. The main aim of this project is deepening our understanding of the impact of undergoing economic, social, cultural, technological and labour change in Spanish universities in the life and professional identity of the teaching and research staff, taking into account the national and european context. This paper gathers part of the results gained from the project, being its primary objective to contribute to an improved knowledge-base on professional knowledge and work experience in higher education institutions in Spain and, as a consequence, to understand how Spanish academics are coping with current changes.[spa] Este documento forma parte de la investigación, Los efectos de los cambios sociales en el trabajo y la vida profesional de los docentes universitarios, parcialmente financiado por el Ministerio de Ciencia e Innovación (SEJ2006-01876), en el que hemos explorado los cambios en la legislación, la organización, los contextos de la investigación y la docencia, etc., en los últimos treinta años. El principal objetivo de este documento es profundizar en nuestra comprensión sobre el impacto del cambio económico, social, cultural, tecnológico y laboral que están experimentando las universidades españolas en la vida y la identidad profesional del personal docente e investigador, teniendo en cuenta el contexto nacional y europeo. Este trabajo recoge parte de los resultados obtenidos en el proyecto, siendo su principal objetivo contribuir a mejorar el conocimiento basado en la investigación sobre el saber profesional y la experiencia laboral en las universidades españolas, y en consecuencia, favorecer nuestra comprensión sobre cómo los académicos se están enfrentando con los cambios actuales.[cat] Aquest document forma part de la investigació, Els efectes dels canvis socials en el treball i la vida professional dels docents universitaris, parcialment finançat pel Ministeri de Ciència i Innovació (SEJ2006-01876), on hem explorat els canvis de la legislació, l'organització, els contextos d'investigació i docència etc., durant els darrers trenta anys. El principal objectiu d'aquest document és aprofundir en la comprensió de l'impacte del canvi econòmic, social, cultural, tecnològic i laboral que s'està experimentant a les universitats espanyoles en la vida i en la identitat professional de les persones docents i investigadores, tenint en compte el context nacional i europeu. Aquest treball recull part dels resultats obtinguts en el projecte, essent el seu principal objectiu contribuir a la millora del coneixement basat en la investigació sobre el saber professional i l'experiència laboral a les universitats espanyoles, i conseqüentment, afavorir la comprensió sobre com els acadèmics estan encarant els actuals canvis

    The retrieval of moving images at Spanish film archives: the oversight of content analysis

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    In the field of library and information science, content analysis is a crucial task for an effective retrieval of information by users at an archive. In this research, we analyse the current state of this task and the possibilities of retrieval of film information at six Spanish important film archives, interviewing their responsible librarians for film cataloguing and comparing the content fields inside their film cataloguing records used by each one of these six organizations

    The reduction of plankton biomass induced by mesoscale stirring: a modeling study in the Benguela upwelling

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    Recent studies, both based on remote sensed data and coupled models, showed a reduction of biological productivity due to vigorous horizontal stirring in upwelling areas. In order to better understand this phenomenon, we consider a system of oceanic flow from the Benguela area coupled with a simple biogeochemical model of Nutrient-Phyto-Zooplankton (NPZ) type. For the flow three different surface velocity fields are considered: one derived from satellite altimetry data, and the other two from a regional numerical model at two different spatial resolutions. We compute horizontal particle dispersion in terms of Lyapunov Exponents, and analyzed their correlations with phytoplankton concentrations. Our modelling approach confirms that in the south Benguela there is a reduction of biological activity when stirring is increased. Two-dimensional offshore advection and latitudinal difference in Primary Production, also mediated by the flow, seem to be the dominant processes involved. We estimate that mesoscale processes are responsible for 30 to 50% of the offshore fluxes of biological tracers. In the northern area, other factors not taken into account in our simulation are influencing the ecosystem. We suggest explanations for these results in the context of studies performed in other eastern boundary upwelling areas

    Student interactions in online discussion forums: their perception on learning with business simulation games

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    Digital technology offers new teaching methods with controversial results over learning. They allow students to develop a more active participation in their learning process although it does not always drive to unequivocal better learning outcomes. This study aims to offer additional evidence on the contribution of business simulation games to students' learning outcomes, considering student interactions in online discussion forums. We conducted a qualitative research with the online discussion forums of 5 different courses at bachelor and master levels, which involves 41 students' teams. The final sample was composed of 3681 messages posted by the students. The results reveal that some generic and specific managerial skills exert a positive influence on learning outcomes. Students mostly highlighted teamwork, decision-making, information processing, reaching agreements, and dealing with uncertainty as the most relevant contributions of the game towards their learning. These results have instructional and pedagogical implications for determining the best way to enhance students' motivation and learning outcomes when using digital technology methods, which involves recommendations that affect their design and monitoring

    Are tax subsidies for private medical insurance self-financing? Evidence from a microsimulation model for outpatient and inpatient episodes

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    This paper analyses whether or not tax subsidies to private medical insurance are self-financing by means of a structural approach. We construct a simulation routine based on a microeconometric discrete choice model that allows us to evaluate the impact of premium changes on the utilisation of outpatient and inpatient health care services. We simulate the 1999 Spanish tax reform that abolished the tax deduction for expenditures on private health insurance using a representative sample of the Catalan population. Prior to this reform, foregone tax revenue arising from deductions after the purchase of private insurance amounted to €69.2 M. per year. In contrast, the elimination of the subsidies to private policies is estimated to generate an extra cost for the public sector of about €8.9 M. per year.Health care utilisation, structural modelling, tax reform evaluation

    Avalanche dynamics in fluid imbibition near the depinning transition

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    We study avalanche dynamics and local activity of forced-flow imbibition fronts in disordered media. We focus on the front dynamics as the mean velocity vˉ\bar{v} of the interface is decreased and the pinning state is approached. Scaling arguments allow us to obtain the statistics of avalanche sizes and durations, which become power-law distributed due to the existence of a critical point at vˉ=0\bar{v}= 0. Results are compared with phase-field numerical simulations
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