788 research outputs found

    Mixing in convective thermal fluxes in unsteady nonhomogeneous flows generating complex three dimensional vorticity patterns

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    Diffusion and scaling of the velocity and vorticity in a thermoelectric driven heating and cooling experimental device is presented in order to map the different patterns and transitions between two and three dimensional convection in an enclosure with complex driven flows. The size of the water tank is of 0.2 x 0.2 x 0.1 m and the heat sources or sinks can be regulated both in power and sign [1-3]. The thermal convective driven flows are generated by means of Peltier effects in 4 wall extended positions of 0.05 x 0.05 cm each. The parameter range of convective cell array varies strongly with the Topology of the boundary conditions. Side heat and momentum fluxes are a function of Rayleigh, Peclet and Nusselt numbers, [4-6] Visualizations are performed by PIV, Particle tracking and shadowgraph. The structure of the flow is shown by setting up a convective flow generated by buoyant heat fluxes. The experiments described here investigate high Prandtl number mixing using brine and fresh water in order to form a density interface and low Prandtl number mixing with temperature gradients. The evolution of the mixing fronts are compared and the topological characteristics of the merging of the convective structures are examined for different configurations. Based on two dimensional Vorticity spectral analysis, new techniques can be very useful to determine the evolution of scales considering the multi-fractal structure of the convective flows.Peer ReviewedPostprint (published version

    Evaluation and design of EFL didactic materials. Audiovisual texts for the English class in primary education

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    Trabajo en el que se ve reflejado la creación de actividades para el área de inglés, utilizando las TICs y en las cuales se busca sobre todo práctica de las habilidades orales, todo ello apoyado por unas bases teóricas concretas y siguiendo el enfoque conocido como -communicative approach

    Biodiversity of epiphytic macroalgae (Chlorophyta, Ochrophyta, and Rhodophyta) on leaves of Zostera marina in the northwestern Iberian Peninsula

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    [Abstract] The composition, abundance, and distribution of epiphytic macroalgae living in meadows of Zostera marina L. in the northwestern Iberian Peninsula are here analyzed. We identified 63 species: 40 red algae, 16 brown algae, and 7 green algae. Most of them are classified as filamentous or filiform functional forms, while Pneophyllum fragile Kütz. was the only encrusting species. In general, the surface covered by epiphytes on the leaves of Zostera marina was low and a 43% of species were only found in juvenile stages. Regarding their frequency, 10 species were collected in the majority of the areas, while others were rare. Most species were found both epiphytic and in other substrata of the meadows, but 9 were exclusively epiphytic. We detected 9 introduced species.[Resumen] Se han analizado la composición, la abundancia y la distribución de macroalgas epifitas que viven en praderas de Zostera marina L. del noroeste de la península ibérica. Se han identificado 63 especies: 40 algas rojas, 16 pardas y 7 verdes. La mayoría pertenecen a los grupos funcionales filamentosos o filiformes, excepto Pneophyllum fragile Kütz., la única especie costrosa. En general, la cobertura de epifitos en las hojas de Zostera marina fue baja y un 43% de las especies solo se encontraron como estadios juveniles. En cuanto a su frecuencia, 10 de ellas se recolectaron en la mayoría de las áreas, mientras que el resto fueron más raras. La mayor parte de las especies se encontraron tanto epifitas como en otros substratos de las praderas, si bien 9 resultaron exclusivamente epifitas. Detectamos 9 especies introducidas.Xunta de Galicia; GPC2015/02

    Carbohydrate patterns in the digestive tract of Sparus aurata L. and Psetta maxima (L.) (Teleostei) parasitized by Enteromyxum leei and E. scophthalmi (Myxozoa)

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    33 p., figuras, tablas y bibliografíaThe influence of Enteromyxum spp. infections on the carbohydrate patterns of the digestive tract of gilthead sea bream (GSB) Sparus aurata L. and turbot (TB) Psetta maxima (L.) has been studied. Histochemical stainings to differentiate the types of mucins and lectin-binding assays to detect terminal carbohydrate residues were applied to histological sections of GSB and TB uninfected or infected by Enteromyxum leei and E. scophthalmi, respectively. The number of intestinal GC decreased in severely infected fish in both parasitoses, though changes in mucin patterns were limited to the decrease in the staining intensity for acidic mucins in infected GSB. The TB stomach and intestine lacked histochemically detectable acidic mucins, or sialic acid detectable by SNA, in contrast with their abundance in GSB. Glucose/mannose, fucose and GlcNAc residues were less abundant in both infected hosts with respect to uninfected fish. In contrast, D-Gal and D-GalNAc moieties (detectable by BSL I) increased in most parts of E. scophthalmi-infected TB while decreasing (oesophagus) or remaining unchanged (intestine) in E. leei-infected GSB. The decreasing in the expression of acidic mucins and of sialic acid detectable by SNA in E. leei-infected GSB is remarkable. Differences in the carbohydrate patterns between both hosts could aid to explain the differences in the severity of both enteromyxoses. In addition, the changes induced by Enteromyxum spp. infections in the digestive tract of GSB and TB suggest a role of terminal carbohydrate residues in the parasite-host interaction.Funding for this work was obtained from the Spanish Ministry of Science and Education through the research project AGL2006-13158-C01. M. J. Redondo is recipient of a CSIC I3P contract funded by the European Social Fund.Peer reviewe

    Bibliotecas universitarias españolas en la web social

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    Overview of the implementation of social web technologies in Spanish university libraries. The research made it possible to determine, among other issues, the reasons why these libraries use (or not) the social web, which 2.0 services are used more and less and for what purposes, obstacles faced by the libraries in carrying out a process of this type, etc. Furthermore, the study attempted to quantify the degree of adoption of these technologies with the help of new measures designed as part of the research process

    Multiscaling properties on sequences of turbulent plumes images

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    A multifractal analysis on a finite-range-scale of the plume concentration images at different experimental conditions (the height of the source Ho), where the measure is the grey value of the image (from 0 to 255), was applied to study its structure through time. The multifractal spectrum showed the characteristic inverse U-shape and a similar evolution in all Ho. The variation of the Hölder exponent (¿a) presented different amplitudes at different moments and increased with time. The symmetry of the spectrum (¿f) decreased with time achieving negative values (from left hand asymmetry evolving to right asymmetry). We show the different behaviour of axial velocity (W) with ¿a and ¿f. There is a linear relation of entrainment coefficient (ae) and the entropy dimension (a1). Therefore, the multifractal spectrum and the derived parameters can be used as markers of plume evolution as well as to study the effect of experimental conditions.Postprint (published version

    Síndrome de TAR y estado de heterocigosis para anemia falciforme

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    Resumen Presentación de un paciente con el cuadro clínico del síndrome de TAR, quien presenta además un estado de heterocigosis para anemia falciforme. El síndrome de TAR, descrito por primera vez en 1959 por Shaw y Oliver, es un trastorno genético no común que ocurre con una prevalencia aproximada de 1: 500.000 a 1: 1.000.000 de nacidos vivos. En 1969 Hall y col. delinearon los criterios diagnósticos de este síndrome que incluyen ausencia bilateral del radio con presencia de ambos pulgares y trombocitopenia. Otras anomalías descritas en menor frecuencia son: Alteraciones óseas del húmero y cúbito, en los casos severos, focomelia, mal- formaciones de expresión variable en extremidades inferiores, malformaciones cardiacas e intolerancia a la leche de vaca (1, 2). Los hallazgos encontrados en este caso se comparan con los de la literatura y se discute su posible etiología, además de resaltar la importancia de realizar un diagnóstico y tratamiento precoz y preciso especialmente de la trombocitopenia. Palabras clave: Malformaciones congénitas, aplasia, hipoplasia, trombocitopenia, anemia falciforme. Abstract This paper shows a patient with clinical features of the TAR syndrome, who presents heterozigosis state for sickle cell anemia. The TAR syndrome was described by Shaw and Oliver in 1959, it is a rare genetic disease, occurring with an approximate prevalence of 1 case in 500.000 to 1 million births. Hall et al. described the current diagnostic criteria for TAR syndrome in 1969. These include bilateral absence of the radii in the presence of both thumbs and trombocytopenia. Other anomalies described included ulnar or humeral defects and the most severe cases phocomelia, lower limb involvement is variable, cadiac anomalies and cow’s milk intolerance (1,2) In this paper, we compare the findings of the literature review, discuss the ethiology and the importance of a diagnostic and treatment specially for trombocytopenia Key words: Congenital malformations, aplasia, hypoplasia, trombocytopenia, sickle cell anemia

    Pluralismo religioso en Colombia. Sentencias de la Corte Constitucional (1991-2017), a propósito de los casos donde estudiantes o aspirantes a serlo invocan la protección del derecho a la libertad religiosa y de cultos en establecimientos educativos

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    This investigation studies the sentences of the Constitutional Court (1991-2017) of Colombia related to cases where students or applicants to educational institutions invoke the right to freedom of religion and worship. First, the text points to the importance that religion has had for humanity in general, and for modern societies in particular, demonstrating that we have come from a secularist paradigm to one of inclusion of religious diversity. In a second part, the text provides a historical overview of the constitutional dispositions that preceded the current norms on religious issues and the transition towards a secular State. In addition, we reference national and international standards related to religious freedom and education, standards which manifest the right of individuals to externalize their beliefs and the importance of education for the construction of pluralist societies where differences must live together. The third part of the text presents the jurisprudential line of the Constitutional Court (1991-2017) on the right to freedom of religion and worship, where this right is invoked by students or applicants to educational institutions. This jurisprudential line allows to show the foundations, arguments and norms that have supported the judgments of this High Court. It also allows us to observe how the Constitutional Court, through its rulings, has decided on the matter of concern. Thus, it is concluded that the Constitutional Court has not always ruled in the same line of thought: in some cases, it has taken its decision following a liberal stance, while in other cases it has followed a conservative one. In the first type of cases, it has given priority to the protection of the right of the students to profess their religious affiliation freely, while in the second type of cases it decided to protect the rights of the educational establishments.Esta investigación estudia las sentencias de la Corte Constitucional (1991-2017), a propósito de los casos donde estudiantes o aspirantes a serlo, invocan la libertad religiosa y de cultos en establecimientos educativos. Primero, se considera la importancia que ha tenido la religión para la humanidad en general, y para las sociedades modernas en particular, demostrando que hemos pasado de un paradigma secularista a uno de inclusión de la diversidad religiosa. En un segundo momento, se plantea un recorrido histórico por las disposiciones constitucionales que antecedieron a las normas vigentes sobre el tema religioso, de esta forma se observa el paso que realizó Colombia hacia un estado laico. Además, se hace referencia a las normas nacionales e internacionales algunas relacionadas con la libertad religiosa y de cultos y otras acerca de la educación, las cuales manifiestan el derecho de la exteriorización de las creencias y la relevancia de la educación para la convivencia de las diferencias, entre otros aspectos. Lo anterior, posibilita estudiar la línea jurisprudencial de la Corte Constitucional (1991-2017) sobre la libertad religiosa y de cultos invocada por estudiantes o aspirantes a establecimientos educativos. Esta línea jurisprudencial, permite evidenciar los fundamentos, argumentos y las normas que han sustentado las sentencias de este alto tribunal. Asimismo, permite observar cómo la Corte Constitucional, a través de sus sentencias ha venido fallando los casos relacionados al tema. Así, pues, se evidencia que en la Corte Constitucional, referente al asunto de la línea jurisprudencial, su orientación no ha sido siempre igual, por tanto, se ha decantado algunas veces, entre una postura de corte liberal, que se encamina hacia el amparo de los derechos de los estudiantes a profesar su libertad religiosa y otras veces se ha inclinado por una postura de corte conservador, en cuanto protege los derechos de los establecimientos educativos.Maestría en Estudios Políticos-InvestigaciónMaestrí
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