949 resultados para Pla, Alberto J.


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Research surrounding the transition from II to I millennium cal BC in Eastern Iberian Peninsula has a large and extensive tradition of investigation. However, the chances to do research on this historical process have been limited by the lack of a well contextualized and dated stratigraphic sequence. For this reason, recent studies in this topic have followed the periodic proposals which were developed in closer regions and areas, especially in the South East and North East of the Peninsula. The investigation perspective about the Late Bronze in Eastern Iberian has however now improved, with the development of several archaeological investigations, the increase in the number of sites being dated and more recent studies into the region helping to bring about this change. As such, it is now in the correct state to be able to propose a new periodization and delve into the changes which occurred in the transition between 1500 and 725 cal BC.

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Cette étude est destinée à la production et à la caractérisation des composites d’acide polylactique (PLA) et des fibres naturelles (lin, poudre de bois). Le moussage du PLA et ses composites ont également été étudiés afin d’évaluer les effets des conditions de moulage par injection et du renfort sur les propriétés finales de ces matériaux. Dans la première partie, les composites constitués de PLA et des fibres de lin ont été produits par extrusion suivit par un moulage en injection. L’effet de la variation du taux de charge (15, 25 et 40% en poids) sur les caractéristiques morphologique, mécanique, thermique et rhéologique des composites a été évalué. Dans la deuxième étape, la poudre de bois (WF) a été choisie pour renforcer le PLA. La préparation des composites de PLA et WF a été effectuée comme dans la première partie et une série complète de caractérisations morphologique, mécanique, thermique et l’analyse mécanique dynamique ont été effectués afin d’obtenir une évaluation complète de l’effet du taux de charge (15, 25 et 40% en poids) sur les propriétés du PLA. Finalement, la troisième partie de cette étude porte sur les composites de PLA et de renfort naturel afin de produire des composites moussés. Ces mousses ont été réalisées à l’aide d’un agent moussant exothermique (azodicarbonamide) via le moulage par injection, suite à un mélange du PLA et de fibres naturelles. Dans ce cas, la charge d’injection (quantité de matière injectée dans le moule: 31, 33, 36, 38 et 43% de la capacité de la presse à injection) et la concentration en poudre de bois (15, 25 et 40% en poids) ont été variées. La caractérisation des propriétés mécanique et thermique a été effectuée et les résultats ont démontré que les renforts naturels étudiés (lin et poudre de bois) permettaient d’améliorer les propriétés mécaniques des composites, notamment le module de flexion et la résistance au choc du polymère (PLA). En outre, la formation de la mousse était également efficace pour le PLA vierge et ses composites car les masses volumiques ont été significativement réduites.

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Les matériaux composites sont utilisés dans beaucoup de domaines pour leurs propriétés mécaniques spécifiques, leur mise en forme facile et leur bas coût. Cependant, lorsque les composites pétro-sourcées sont en fin de vie, le traitement des déchets a un fort impact environnemental. C’est pour cette raison que les industriels se tournent vers des matériaux bio-sourcés. Ils souhaitent ainsi abaisser le coût des matières premières mais aussi se donner une image plus « verte » grâce à l’utilisation de matériaux renouvelables et/ou compostables. Le projet présenté s’inscrit dans dans cette optique où il est question d’élaborer de nouveaux composites à renfort et matrices bio-sourcés et tout particulièrement des composites fibre de lin/acide polylactique (PLA). Ces derniers sont généralement appelés bio-composites. L’originalité de cette étude réside dans le traitement des fibres de lin afin de les compatibilité avec la matrice PLA. Le traitement consiste au greffage de dioxyde de titane sur la surface de fibres de lin fonctionnalisée par oxydation au TEMPO. Ces fibres longues sont ensuite utilisées comme renfort sous forme de tissu unidirectionnel dans la matrice PLA. Le comportement mécanique en traction, flexion et la résistance à l’impact de ces biocomposites sont étudiés afin d’analyser l’influence du traitement des fibres sur leur performances.

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The first of the four paths that structure the book "Los girasoles ciegos", by Alberto Méndez – with its theory about the delayed end of the Spanish Civil War as a longing for destruction outside of any kind of strategy based on military logic – presents the construction of a memory based on certain oral marks, facts provided quietly by apparently non-central characters, the distrust of written documents, and the use of speech patterns mostly associated with spontaneity in order to set up a level of verisimilitude which makes the memory emerge in parallel pathways considered relatively reliable (for example, the case of a report), forged speech on the basis of indirect references, testimonials and letters. The aim of the paper is to consider an example of contemporary Spanish narrative in which a journey, perhaps weak in terms of the material, support to the channels through which the narrator comes in the story through the voice of the people – but functional as an approach to a search of the recent past – contributes to a certain conception of memory.

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El poema "A Aristo" es el más atípico de los poemas de inspiración horaciana de Alberto Lista. Ello se debe a que no constituye adaptación de un poema horaciano concreto, sino que combina ingredientes de al menos dos en un proceso de contaminatio. Menéndez Pelayo consideraba que el poema recordaba de forma global el estilo horaciano, sin especificar fuentes concretas, pero hemos podido rastrear la procedencia del tema general y de motivos específicos en dos odas horacianas (carm. 1, 26 y 4, 3).

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This article means a first approach to the information given to its readers by the magazine Destino about the France of the IV French Republic, exactly during Pierre Mendès-France´s term in 1954, and having its origin in four articles published by the journalist and writer Josep Pla just when the Algeria conflict started. That information was determined by the obsessive anti-communist editorial policy of the aforementioned charismatic publication of the francoist Spain.

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Este estudo caracteriza a incidência do excesso de peso e da obesidade no Externato João Alberto Faria (Arruda dos Vinhos), procurando identificar as variáveis que os determinam e definir um projecto de intervenção na área da educação para a saúde no âmbito dos estilos de vida saudáveis e do combate ao excesso de peso e à obesidade. Dos 432 alunos que participaram no estudo, 53,7°/o eram do sexo feminino e 46,3% do sexo masculino. Os resultados relativos ao índice de Massa Corporal (IMC) dos alunos indicaram que, na população em estudo, 31,7% dos alunos apresentavam peso em excesso, dos quais 10,5% eram obesos. A prevalência de excesso de peso e obesidade era superior nos alunos mais novos e nas raparigas, no entanto os rapazes eram mais obesos. Em virtude dos resultados, identificaram-se como áreas de intervenção, a melhoria dos hábitos alimentares, o aumento dos níveis de actividade física e a diminuição das catividades de lazer sedentárias dos alunos, bem como intervenções ao nível das crenças, atitudes e comportamentos dos alunos e dos pais. O projecto de intervenção apresentado tem como objectivo reduzir a prevalência do excesso de peso e obesidade infantil através da aquisição e desenvolvimento de atitudes e comportamentos que visem a promoção e adopção de hábitos e estilos de vida saudáveis. É sabido que mudar atitudes e comportamentos, nomeadamente, os que dizem respeito a mudança de estilos de vida, é um processo difícil e que leva tempo, sendo fundamental uma abordagem integrada que afecte as várias dimensões das causas do problema em que se pretende intervir. ABSTRACT; This study characterizes the incidence of overweight and obesity in Externato João Alberto Faria (Arruda dos Vinhos). lts aim was to identify the variables that causes it and to define a project of intervention in the health educational field related to healthy lifestyles and against overweight and childhood obesity. 432 students participated in the survey: 53,7% females and 46,3% males. The results as far as students Body Mass Index are concerned show that within the surveyed people 31,7% were overweight and 10,5% were obese. Overweight and obesity have more evidence in the younger students and in the girls' group, despite the fact that boys were more obese. Such results lead to the intervention in certain areas: improving eating habits, increasing physical activity, diminishing sedentary hobbies and also interfering in the beliefs and attitudes of children and their parents. The intervention project presented has the following goal: to reduce the prevalence of overweight and childhood obesity through the acquisition and development of attitudes and behaviours witch aim at de promotion and adoption of healthy habits and lifestyles. Changing attitudes and behaviours related to the improving of lifestyles is difficult and takes time. Therefore, the need for an integrated approach is crucial in order to affect the several causes of the problem in witch we want to intervene.

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Fondo Margaritainés Restrepo

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Fondo Margaritainés Restrepo

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Flavonoids are potent anti-inflammatory compounds isolated from several plant extracts, and have been used experimentally against inflammatory processes. In this work, a PLA(2) isolated from the Crotalus durissus cascavella venom and rat paw oedema were used as a model to. study the effect of flavonoids on PLA(2). We observed that a treatment of PLA(2) with morin induces several modifications in the aromatic amino acids, with accompanying changes in its amino acid composition. In addition, results from circular dichroism spectroscopy and UV scanning revealed important structural modifications. Concomitantly, a considerable decrease in the enzymatic and antibacterial activities was observed, even though anti-inflammatory and neurotoxic activities were not affected. These apparent controversial results may be an indication that PLA(2) possess a second pharmacological site which does not affect or depend on the enzymatic activity. (c) 2005 Elsevier Ltd. All rights reserved.

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In the present article we report on the biological characterization and amino acid sequence of a new basic Phospholipases A(2) (PLA(2)) isolated from the Crotalus durissus collilineatus venom (Cdcolli F6), which showed the presence of 122 amino acid residues with a pI value of 8.3, molecular mass of 14 kDa and revealed an amino acid sequence identity of 80% with crotalic PLA(2)s such as Mojave B, Cdt F15, and CROATOX. This homology, however, dropped to 50% if compared to other sources of PLA(2)s such as from the Bothrops snake venom. Also, this PLA(2) induced myonecrosis, although this effect was lower than that of BthTx-I or whole crotoxin and it was able to induce a strong blockage effect on the chick biventer neuromuscular preparation, independently of the presence of the acid subunid (crotapotin). The neurotoxic effect was strongly reduced by pre-incubation with heparin or with anhydrous acetic acid and rho-BPB showed a similar reduction. The rho-BPB did not reduce significantly the myotoxic activity induced by the PLA(2), but the anhydrous acetic acid treatment and the pre-incu-bation of PLA(2) with heparin reduced significantly its effects. This protein showed a strong antimicrobial activity against Xanthomonas axonopodis passiflorae (Gram-negative), which was drastically reduced by incubation of this PLA(2) with rho-BPB, but this effect was marginally reduced after treatment with anhydrous acetic acid. Our findings here allow to speculate that basic amino acid residues on the C-terminal and molecular regions near catalytic site regions such as Calcium binding loop or rho-wing region may be involved in the binding of this PLA(2) to the molecular receptor to induce the neurotoxic effect. The bactericidal effect, however, was completely dependent on the enzymatic activity of this protein.

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Este artículo pretende ofrecer herramientas analíticas acerca de diversos aspectos que sean de utilidad a los pianistas profesionales o en formación, para el estudio y ejecución de la Sonata para Piano No.1, Op.22 del compositor argentino Alberto Ginastera -- Se incluye un corto contexto histórico de la obra, con especial enfoque en el período creativo del que hace parte la Sonata, con el fin de familiarizar al pianista con la producción del compositor -- Cuenta el artículo además con un análisis de la estructura de la obra y de cada uno de sus movimientos y con consejos prácticos enfocados al aspecto técnico ejecutivo-interpretativo, cuyo fin es facilitar, tanto el estudio como la ejecución misma de la obra -- Se incluye también un breve análisis de tres grabaciones de la Sonata con comentarios generales relacionados con los asuntos puntuales atendidos en el artículo