952 resultados para Barrios
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Objective: To determine the risk of lung cancer associated with exposure at home to the radioactive disintegration products of naturally Occurring radon gas. Design: Collaborative analysis of individual data from 13 case-control studies of residential radon and lung cancer. Setting Nine European countries. Subjects 7148 cases Of lung cancer and 14 208 controls. Main outcome measures: Relative risks of lung cancer and radon gas concentrations in homes inhabited during the previous 5-34 years measured in becquerels (radon disintegrations per second) per cubic incite (Bq/m(3)) Of household air. Results: The mean measured radon concentration in homes of people in tire control group was 97 Bq/m(3), with 11% measuring > 200 and 4% measuring > 400 Bq/m(3). For cases of lung cancer the mean concentration was 104 Bq/m(3). The risk of lung cancer increased by 8.4% (95% confidence interval 3.0% to 15.8%) per 100 Bq/m(3) increase in measured radon (P = 0.0007). This corresponds to an increase of 16% (5% to 31%) per 100 Bq/m(3) increase in usual radon-that is, after correction for the dilution caused by random uncertainties in measuring radon concentrations. The dose-response relation seemed to be linear with no threshold and remained significant (P=0.04) in analyses limited to individuals from homes with measured radon < 200 Bq/m(3). The proportionate excess risk did not differ significantly with study, age, sex, or smoking. In the absence of other causes of death, the absolute risks of lung cancer by age 75 years at usual radon concentrations of 0, 100, and 400 Bq/m(3) would be about 0.4%, 0.5%, and 0.7%, respectively, for lifelong non-smokers, and about 25 times greater (10%, 12%, and 16%) for cigarette smokers. Conclusions: Collectively, though not separately, these studies show appreciable hazards from residential radon, particularly for smokers and recent ex-smokers, and indicate that it is responsible for about 2% of all deaths from cancer in Europe.
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We have calculated the concentrations of Mg in the bulk and surfaces of aragonite CaCO3 in equilibrium with aqueous solution, based on molecular dynamics simulations and grand-canonical statistical mechanics. Mg is incorporated in the surfaces, in particular in the (001) terraces, rather than in the bulk of aragonite particles. However, the total Mg content in the bulk and surface of aragonite particles was found to be too small to account for the measured Mg/Ca ratios in corals. We therefore argue that most Mg in corals is either highly metastable in the aragonite lattice, or is located outside the aragonite phase of the coral skeleton, and we discuss the implications of this finding for Mg/Ca paleothermometry.
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We have investigated the (001) surface structure of lithium titanate (Li2TiO3) using auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and scanning tunneling microscopy (STM). Li2TiO3 is a potential fusion reactor blanket material. After annealing at 1200 K, LEED demonstrated that the Li2TiO3(001) surface was well ordered and not reconstructed. STM imaging showed that terraces are separated in height by about 0.3 nm suggesting a single termination layer. Moreover, hexagonal patterns with a periodicity of ∼0.4 nm are observed. On the basis of molecular dynamics (MD) simulations, these are interpreted as a dynamic arrangement of Li atoms.
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This essay will examine and compare the production of women's writing during and after the Nicaraguan and Cuban Revolutions, a corpus that includes novels, poetry, and testimonies, but also features considerable generic hybridity. Since both revolutions are separated by some twenty years, each must be understood in the context of the specific ideological conditions that framed women’s participation in culture and revolution, and must also be considered in light of evolving gender discourses, both national and international. As such, these texts respond to both local and transnational paradigms of feminine subjectivity, and highlight the particular problems that arise from women’s insertion into the revolution and its representation in literature. These writers also have to negotiate the evolving context of revolution itself, with its moments of euphoria and disenchantment – and it is here that the greatest contrasts can be found between the two revolutionary instances and their political features: whilst Cuba’s revolutionary process has somehow survived economic crisis and created a level of political stability and continuity (not without its own problems), the Nicaraguan case is characterised by ruptures and resentments which are clearly reflected in the work of writers before, during, and after the Sandinista revolution, and which continue to the present day. This chapter will address the work of the most prominent woman writer of the Nicaraguan revolution, Gioconda Belli, whose main work reflects her involvement in the Sandinista struggle; ex-commander Mónica Baltodano has recently compiled a four volume piece with testimonials of men and women who participated in the organization and actions led by the Frente Sandinista de Liberación Nacional, and Violeta Barrios de Chamorro, former president of Nicaragua, who has recently co-authored an autobiography. There are other women poets to consider, especially under the auspices of the Asociación de Mujeres Nicaraguenses Luisa Amanda Espinoza, such as Vidaluz Meneses, Michele Najlis and Daisy Zamora. The testimonios compiled by Margaret Randall are also important pieces to consider for both Nicaragua and Cuba. The most important voices of the Cuban revolution still resident on the island are poet Nancy Morejón and writers Mirta Yáñez and Aida Bahr, with younger writers such as Adelaida Fernández de Juan and Marilyn Bobes representing a more recent generation.
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Mediante a realização de pesquisa empírica concentrada em dois estudos de caso, o trabalho prop~em-se a analisar as práticas do planejamento dos recursos humanos ao nível nacional no Panamá. O estudo das diferentes abordagens sobre a utilização da conceituação dos recursos humanos, revela a importância que a estes lhe é atribuída do desenvolvimento econômico de um país. Sendo assim, é colocada a necessidade de considerar, na elaboração dos planos nacionais, o planejamento dos recursos humanos, como forma de atingir os objetivos e metas pretendidas no primeiro. A partir dos resultados das análises e do estudo dos diversos modelos do planejamento, sugere-se implementar um novo modelo de planejamento ao nível intermediário, especificamente na área de recursos humanos, caracterizando a importância da interação de grupos e a produção e avaliação de informações, cujos resultados finais sejam encaminhados aos níveis decisórios para os ajustes necessários no processo de desenvolvimento dos recursos humanos. Procura este processo, um mecanismo mais viável e coerente entre as políticas globais e de desenvolvimento de recursos humanos, visualisando uma adequada formação, treinamento e utilização dos recursos humanos no país
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Este estudio tiene como objetivo evaluar los avances y límites de las políticas de accesibilidad en la ciudad de Natal. Se investigan las políticas publicas municipales de accesibilidad implantadas en los diez años subsecuentes, a partir de la sanción de la Ley Municipal de Accesibilidad Nº 4.090 del 03 de junio de 1992, que torna obligatorio la eliminación de las barreras arquitectónicas para personas con discapacidades en los lugares de circulación de peatones y edificios de uso público de la ciudad. Accesibilidad, en los proyectos de arquitectura y urbanismo es la condición esencial para asegurar a cualquier ciudadano su derecho a ir y venir con seguridad, dignidad y autonomía. Esta investigación se concentra en los barrios de: ciudad alta, Petrópolis y Ribeira, ya que esta área, en el período ya mencionado, fue la que tuvo una mayor concentración del presupuesto de inversiones públicas municipales de la ciudad de Natal, en la eliminación de barreras arquitectónicas en vías urbanas. El método adoptado fue el hipotético deductivo, a partir de la formulación de dos hipótesis de trabajo: la primera, una divergencia entre los objetivos propuestos por la Ley Nº 4.090 y sus aplicaciones prácticas y, la segunda, de las diferencias que existen en el grado de entendimiento del concepto de accesibilidad, para eso, se realizó una colecta y análisis de datos tanto empíricos como teóricos. Este estudio también retrata en el año de 2004, con el uso de la técnica de la fotografía, la realidad actual de la ciudad sirviendo como un parámetro comparativo con los proyectos asociados a la Coordinación para integración de las personas con discapacidades. Se utiliza la técnica de entrevista con especialistas en accesibilidad envueltos a lo largo del proceso de implantación de las políticas públicas en la ciudad de Natal, durante los años mencionados, obteniendo así un testimonio sobre las directrices adoptadas en ese período, con base en la legislación vigente. En la investigación documental y fotográfica se realiza una evaluación de la dimensión real de lo propuesto y ejecutado en un periodo de diez años, y se concluye sobre todos los avances y retrocesos de las políticas de gestiones públicas adoptadas con relación a la accesibilidad en la ciudad de Natal
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Two new benzoic acid esters of triterpene alcohols [lup-20 (29)-en-28-oic acid 3 alpha, 7 beta -dibenzoate and 3 alpha -hydroxy-lup-20(29)-en-28-ic acid 7 beta -benzoate] were isolated from the stem bark of Picramnia teapensis Tul. The structures of these compounds were established on the basis of spectral analyses. Other known compounds, beta -sitosterol, estigmasterol, lupeol and epilupeol, were identified in mixture by GC-MS. The triterpene esters have not shown in-vitro inhibitory effect on the growth of Leucoagaricus gongylophorus (Fisher), referred also as Leucocoprinus gongylophorus (Heim), syn Rozites gongylophora (Moller), the symbiotic fungus cultivated by the leaf-cutting ant Atta sexdens L.
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This dissertation aims at analyzing some relations established between teachers‟ formative proposal for docent knowledge and pedagogical practices in the Special Program of Professional Formation to Basic Education (Proformação in Portuguese) with the objective of investigating how teachers evaluate knowledge acquired during their course formation to identify its improvement in their pedagogical practice. This is a Pedagogical Program of the State University of Rio Grande do Norte chosen to be analyzed. The objective is to investigate how teachers, Proformação/Pedagogy course students evaluate privileged knowledge in that university formation and how the relation between this knowledge and their pedagogical practice are experienced in classroom as teachers, defining in which way knowledge constructed and reconstructed during the course contributes for an improvement of their pedagogical practices. We have interviewed fourteen Proformação/Pedagogy last-term teachers, emphasizing the analysis of their point of view as social actors related to docent university formation in service. The principles for this investigation comprehend a qualitative approach, in a case study modality, with an exploratory tendency, presented in the introductory section and along four chapters. The research is theoretically guided by Andoino (1998), Bardin (2009); Laville e Dione (1999); Bogdan and Biklen (1994), Hernandez Sampieri, Hernandez Collado and Baptista Lúcio (2006), among others. We justify this thematic choice, considering docent formation and its interface with an improvement for students‟ leaning, taking into account the strict relations between those elements. We have discussed on docent formative paradigms, based on a multireferential perspective, whose main authors that developed research in this area are: Gómez (1998), Sacristán e Gómez (1998), Tardif (2002), Altet (2001) Paquay e Wagner (2001), Garcia (1999), Baldi (2008), La Torre e Barrios (2002). We interviewed fourteen teachers, all of them in the last term of the Program. In the second chapter, we justify the choice of the subject, approaching docent formation and its relation with basic teaching. We understand that there is a strong relation between those aspects. In the third chapter, we discuss on some docent formative paradigms, among them, Gomes (1998), Sacristán and Gomez (1998), Tardig (2002), Altet (2001) Paquay and Wagner (2001), Garcia (1999), Baldi (2008), La Torre and Barrios (2002). We introduce the Pedagogical Program structure and specify which formative paradigms characterize it and identifying that one of the most prominent paradigm is a practical perspective with emphasis on reflexivity about the practice based on the premise that docent formation is be based on from learning to practice theory. We present an data analysis obtained from thematic categorization extracted subjects‟ discourses and, at the end, we discuss on evaluation of the teachers involved in the research related to the course contributions to provide an improvement for pedagogical practices developed by them inside their classrooms. We consider, thus, that teachers evaluate the Program as a guideline for (re)construction of diversified knowledge, which, in turn, provides the development of abilities to analyze classroom situations based on pedagogical theories and to develop investigative practice based on everyday experience. The results point out that some implications are relevant, among them: the thematic-choice, discussed previously, needs other kinds of investigations. The relation between theory and practice proposed in formation programs requires more systematic studies considering others aspects that characterize teaching process, and mainly, to provide investigative proposals of and about such practices
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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We propose a new paradigm for collective learning in multi-agent systems (MAS) as a solution to the problem in which several agents acting over the same environment must learn how to perform tasks, simultaneously, based on feedbacks given by each one of the other agents. We introduce the proposed paradigm in the form of a reinforcement learning algorithm, nominating it as reinforcement learning with influence values. While learning by rewards, each agent evaluates the relation between the current state and/or action executed at this state (actual believe) together with the reward obtained after all agents that are interacting perform their actions. The reward is a result of the interference of others. The agent considers the opinions of all its colleagues in order to attempt to change the values of its states and/or actions. The idea is that the system, as a whole, must reach an equilibrium, where all agents get satisfied with the obtained results. This means that the values of the state/actions pairs match the reward obtained by each agent. This dynamical way of setting the values for states and/or actions makes this new reinforcement learning paradigm the first to include, naturally, the fact that the presence of other agents in the environment turns it a dynamical model. As a direct result, we implicitly include the internal state, the actions and the rewards obtained by all the other agents in the internal state of each agent. This makes our proposal the first complete solution to the conceptual problem that rises when applying reinforcement learning in multi-agent systems, which is caused by the difference existent between the environment and agent models. With basis on the proposed model, we create the IVQ-learning algorithm that is exhaustive tested in repetitive games with two, three and four agents and in stochastic games that need cooperation and in games that need collaboration. This algorithm shows to be a good option for obtaining solutions that guarantee convergence to the Nash optimum equilibrium in cooperative problems. Experiments performed clear shows that the proposed paradigm is theoretical and experimentally superior to the traditional approaches. Yet, with the creation of this new paradigm the set of reinforcement learning applications in MAS grows up. That is, besides the possibility of applying the algorithm in traditional learning problems in MAS, as for example coordination of tasks in multi-robot systems, it is possible to apply reinforcement learning in problems that are essentially collaborative