544 resultados para Altiplano chileno


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Incluye Bibliografía

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La dinámica del consumo energético industrial en América Latina y sus implicancias para un desarrollo sostenible / Hugo Altomonte, Nelson Correa, Diego Rivas y Giovanni Stumpo .-- La desigualdad del ingreso y los mercados de crédito / Adolfo Figueroa .-- Trinidad y Tabago: Desigualdades salariales intersectoriales / Allister Mounsey y Tracy Polius .-- México: Alza de precios de los alimentos y restricciones al crecimiento / Moritz Cruz, Armando Sánchez y Edmund Amann .-- Una mirada al auge exportador chileno / Raphael Bergoeing, Alejandro Micco y Andrea Repetto .-- Chile: Pensión anticipada, impaciencia y aversión al riesgo / Jaime Ruiz-Tagle y Pablo Tapia .-- Márgenes de ganancia, financiamiento e inversión del sector empresarial peruano (1998-2008) / Germán Alarco T. .-- ¿Se debe el mayor rendimiento de las escuelas de gestión privada en la Argentina al tipo de administración? / María Marta Formichella .-- Tecnología, comercio y calificación en el Brasil: Evidencias de datos microeconómicos / Bruno César Araújo, Francesco Bogliacino y Marco Vivarelli .-- Brasil: Cambio estructural y crecimiento con restricción de balanza de pagos / João Prates Romero, Fabrício Silveira y Frederico G. Jayme Jr. .-- Jueces de la Revista CEPAL año 2010 y enero-agosto 2011 .-- Orientaciones para los colaboradores de la Revista cepal.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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A anurofauna do estado de São Paulo, nas últimas oito décadas, tem sido foco do estudo de importantes grupos de pesquisa em anfíbios anuros. Porém, pesquisas realizadas com comunidades na área da Depressão Periférica do centro-oeste paulista ainda são escassas. A fim de trazer novas informações sobre essa região, nosso objetivo foi inventariar a anurofauna de uma área na Depressão Periférica, associando os resultados com dados da literatura e confrontando os mesmos com aqueles conhecidos para a anurofauna no altiplano da Cuesta de Botucatu. O inventário foi realizado a partir dos dados obtidos em 24 dias de amostragem, decorridos 13 meses de coleta (dezembro de 2008 a dezembro de 2009). Os anuros foram amostrados em potenciais sítios reprodutivos, pelos métodos de encontro visual e busca auditiva. Foram registradas 29 espécies distribuídas em 12 gêneros e seis famílias. Apesar da maioria das espécies serem predominantemente de áreas abertas, consideramos a riqueza elevada, e associamos essa riqueza à existência dos remanescentes de mata nos interflúvios. Entretanto, apesar da presença desses remanescentes, a ocorrência de espécies associadas exclusivamente a essas áreas foi pequena, se comparada aos fragmentos no altiplano, fato que aparentemente está associado às diferenças existentes entre os fragmentos contidos nos interflúvios e os fragmentos do altiplano. A atividade dos anfíbios foi concentrada no período quente e úmido, diminuindo à medida que se aproxima o ápice da estação fria e seca. Com base na análise de similaridade, observou-se a formação de agrupamentos com alta sobreposição. Entre esses agrupamentos, destacaram-se aqueles formados por espécies com atividade de vocalização prolongada, mas que diferiram quanto ao período de maior atividade (início e final da estação chuvosa) bem como, aqueles constituídos por espécies com período de vocalização mais curto, restrito a poucos dias, e que também diferiram no mês de pico de atividade (início e final da estação chuvosa). Com isso acreditamos que as diferenças quanto à distribuição temporal dos organismos da comunidade sejam importantes na partilha de recursos e no ajuste das espécies, fato que contribuiu para o elevado número de anfíbios observados e na coexistência dos táxons na área de estudo.

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Pós-graduação em História - FCHS

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Pós-graduação em Letras - FCLAS

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Curved mountain belts have always fascinated geologists and geophysicists because of their peculiar structural setting and geodynamic mechanisms of formation. The need of studying orogenic bends arises from the numerous questions to which geologists and geophysicists have tried to answer to during the last two decades, such as: what are the mechanisms governing orogenic bends formation? Why do they form? Do they develop in particular geological conditions? And if so, what are the most favorable conditions? What are their relationships with the deformational history of the belt? Why is the shape of arcuate orogens in many parts of the Earth so different? What are the factors controlling the shape of orogenic bends? Paleomagnetism demonstrated to be one of the most effective techniques in order to document the deformation of a curved belt through the determination of vertical axis rotations. In fact, the pattern of rotations within a curved belt can reveal the occurrence of a bending, and its timing. Nevertheless, paleomagnetic data alone are not sufficient to constrain the tectonic evolution of a curved belt. Usually, structural analysis integrates paleomagnetic data, in defining the kinematics of a belt through kinematic indicators on brittle fault planes (i.e., slickensides, mineral fibers growth, SC-structures). My research program has been focused on the study of curved mountain belts through paleomagnetism, in order to define their kinematics, timing, and mechanisms of formation. Structural analysis, performed only in some regions, supported and integrated paleomagnetic data. In particular, three arcuate orogenic systems have been investigated: the Western Alpine Arc (NW Italy), the Bolivian Orocline (Central Andes, NW Argentina), and the Patagonian Orocline (Tierra del Fuego, southern Argentina). The bending of the Western Alpine Arc has been investigated so far using different approaches, though few based on reliable paleomagnetic data. Results from our paleomagnetic study carried out in the Tertiary Piedmont Basin, located on top of Alpine nappes, indicate that the Western Alpine Arc is a primary bend that has been subsequently tightened by further ~50° during Aquitanian-Serravallian times (23-12 Ma). This mid-Miocene oroclinal bending, superimposing onto a pre-existing Eocene nonrotational arc, is the result of a composite geodynamic mechanism, where slab rollback, mantle flows, and rotating thrust emplacement are intimately linked. Relying on our paleomagnetic and structural evidence, the Bolivian Orocline can be considered as a progressive bend, whose formation has been driven by the along-strike gradient of crustal shortening. The documented clockwise rotations up to 45° are compatible with a secondary-bending type mechanism occurring after Eocene-Oligocene times (30-40 Ma), and their nature is probably related to the widespread shearing taking place between zones of differential shortening. Since ~15 Ma ago, the activity of N-S left-lateral strike-slip faults in the Eastern Cordillera at the border with the Altiplano-Puna plateau induced up to ~40° counterclockwise rotations along the fault zone, locally annulling the regional clockwise rotation. We proposed that mid-Miocene strike-slip activity developed in response of a compressive stress (related to body forces) at the plateau margins, caused by the progressive lateral (southward) growth of the Altiplano-Puna plateau, laterally spreading from the overthickened crustal region of the salient apex. The growth of plateaux by lateral spreading seems to be a mechanism common to other major plateaux in the Earth (i.e., Tibetan plateau). Results from the Patagonian Orocline represent the first reliable constraint to the timing of bending in the southern tip of South America. They indicate that the Patagonian Orocline did not undergo any significant rotation since early Eocene times (~50 Ma), implying that it may be considered either a primary bend, or an orocline formed during the late Cretaceous-early Eocene deformation phase. This result has important implications on the opening of the Drake Passage at ~32 Ma, since it is definitely not related to the formation of the Patagonian orocline, but the sole consequence of the Scotia plate spreading. Finally, relying on the results and implications from the study of the Western Alpine Arc, the Bolivian Orocline, and the Patagonian Orocline, general conclusions on curved mountain belt formation have been inferred.

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Throughout the world, pressures on water resources are increasing, mainly as a result of human activity. Because of their accessibility, groundwater and surface water are the most used reservoirs. The evaluation of the water quality requires the identification of the interconnections among the water reservoirs, natural landscape features, human activities and aquatic health. This study focuses on the estimation of the water pollution linked to two different environmental issues: salt water intrusion and acid mine drainage related to the exploitation of natural resources. Effects of salt water intrusion occurring in the shallow aquifer north of Ravenna (Italy) was analysed through the study of ion- exchange occurring in the area and its variance throughout the year, applying a depth-specific sampling method. In the study area were identified ion exchange, calcite and dolomite precipitation, and gypsum dissolution and sulphate reduction as the main processes controlling the groundwater composition. High concentrations of arsenic detected only at specific depth indicate its connexion with the organic matter. Acid mine drainage effects related to the tin extraction in the Bolivian Altiplano was studied, on water and sediment matrix. Water contamination results strictly dependent on the seasonal variation, on pH and redox conditions. During the dry season the strong evaporation and scarce water flow lead to low pH values, high concentrations of heavy metals in surface waters and precipitation of secondary minerals along the river, which could be released in oxidizing conditions as demonstrated through the sequential extraction analysis. The increase of the water flow during the wet season lead to an increase of pH values and a decrease in heavy metal concentrations, due to dilution effect and, as e.g. for the iron, to precipitation.

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La Reforma Agraria del 1953 trajo un nuevo régimen y nuevas políticas agrarias que estaban dirigidos a la modernización de Bolivia, y logró la abolición de las formas de servidumbre a las que estaba sometida la población indígena originario campesina. Sin embargo, a más tardar en los años 70, quedó claro que la Reforma Agraria no pudo cumplir con las expectaciones de la población indígena campesina, y que no hubo voluntad política de implementarla. Entre los numerosos déficit de la reforma, destacan la continua inequidad en el acceso y en la distribución de la tierra; la creación de nuevos latifundios de carácter capitalista en el oriente y de minifundios en el altiplano y valle; la inseguridad jurídica; la sobreposición de derechos; y una institucionalidad pública desacreditada. En el marco de cambios políticos en todo Latinoamerica en los años 90, se introdujo una serie de reformas que reconocen el carácter multi-étnico y pluricultural del país. La Ley INRA (Ley del Instituto Nacional de Reforma Agraria) del 1996 trajo un reconocimiento formal de los sistemas de tenencia de la tierra indígenas bajo el patrocinio del neoliberalismo. Un eje central de la ley es el saneamiento de la propiedad agraria. Después de una década de vigencia, la ley resultó ser insuficiente, el saneamiento burocrático, lento, costoso y con resultados no muy satisfactorios. En 2006, el gobierno de Evo Morales modificó la ley mediante la Ley de Reconducción Comunitaria de la Reforma Agraria. Desde entonces, el proceso de saneamiento ha avanzado significantamente en las tierras bajas y el altiplano norte, mientras en Potosí, Tarija, Oruro y Cochabamba el proceso sigue siendo lento. Eso tiene que ver con las particularidades históricas, culturales, sociales, económicas y ecológicas de las diferentes regiones de Bolivia, cuales la Ley INRA no logra a captar. La presente tesis tiene como objetivo analizar las formas de tenencia y uso de la tierra y las instituciones sociales mediantes las cuales estos están reguladas en dos comunidades del Valle de Cochabamba. Las sistemas de tenencia de la tierra elaboradas por las familias campesinas luego se analizaron en relación a la Ley INRA. El área de estudio es localizado en el municipio de Sipe Sipe, provincia de Quillacollo, departamento de Cochabamba. La población consiste de campesinos perteneciendo al grupo etno-lingüistico quechua, cuya subsistencia depende de la producción agropecuaria y, en la mayoría de los casos, del trabajo asalariado. Las comunidades están situadas total- o parcialmente dentro del Parque Nacional Tunari. La ley del parque del 1991 expropia a las personas que viven dentro de los límites de este. Sin embargo, hasta hoy no ha sido implementada, excepto en 1% de la superficie total; las dos comunidades hasta ahora no han sido afectadas. Las dos comunidades de estudio han desarrollado una compleja combinación de propiedad familiar y propiedad comunal, que tiene su raíz en el sistema de haciendas, la forma predominante de tenencia de la tierra en el departamento de Cochabamba hasta la Reforma Agraria. El acceso al territorio comunal y el uso de los recursos naturales es gestionado por un sindicato agrario y una variedad de instituciones sociales. Se analizaron las estrategias de hogar de seis familias de Link’u comparandolas con las demás datos obtenidos. En Lap’iani, la comunidad menos accesible, las familias dependen de gran parte de la producción agropecuaria, mientras en Link’u, que está localizado cerca del pueblo de Sipe Sipe, la mayoría de las familias combina la agricultura con el trabajo asalariado. En ambas comunidades, la educación formal de los hijos y la migración temporal o permanente constituyen pilares fundamentales de las estrategias familiares. En Link’u se ha mostrado un proceso de urbanización que se expresa en un plan de desarrollo futuro que prevée la transformación de la zona periurbana de la comunidad en propiedad familiar o área urbana. Estos cambios en las estrategias de las familias y de la comunidad pueden explicarse por condiciones dinámico socioeconómicas, ecológicas y político-administrativas. Los resultados de la investigación muestran que los campesinos en las comunidades de estudio diversifican sus estrategias de vida para enfrentar al minifundio. Estas estrategias consisten en la producción agropecuaria en diferentes pisos ecológicos (control vertical de la ecología), la educación, la migración, la integración al mercado, el trabajo asalariado, y, en el caso de Link’u, en la propiedad individual de la tierra. El sistema de tenencia de la tierra es marcado por la interlegalidad o el bricolage de leyes formales y normas consuetudinarias. La Ley INRA desempeña para ambas comunidades un papel marginal. Se mostró que el sistema de tenencia y uso de la tierra es complejo, flexible y persistente. Combina diferentes tipos de propiedad y permite diferentes formas de organización dependiendo del área (rural/urbana).

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A glacier–climate model was used to calculate climatic conditions in a test site on the east Andean slope around Cochabamba (17°S, Bolivia) for the time of the maximum Late Pleistocene glaciation. Results suggest a massive temperature reduction of about − 6.4 °C (+ 1.4/− 1.3 °C), combined with annual precipitation rates of about 1100 mm (+ 570 mm/− 280 mm). This implies no major change in annual precipitation compared with today. Summer precipitation was the source for the humidity in the past, as is the case today. This climate scenario argues for a maximum advance of the paleo-glaciers in the eastern cordillera during the global Last Glacial Maximum (LGM, 20 ka BP), which is confirmed by exposure age dates. In a synthesized view over the central Andes, the results point to an increased summer precipitation-driven Late Glacial (15–10 ka BP) maximum advance in the western part of the Altiplano (18°S–23°S), a temperature-driven maximum advance during full glacial times (LGM) in the eastern cordillera, and a pre- and post-LGM (32 ka BP/14 ka BP) maximum advance around 30°S related to increased precipitation and reduced temperature on the western slope of the Andes. The results indicate the importance of understanding the seasonality and details of the mass balance–climate interaction in order to disentangle drivers for the observed regionally asynchronous past glaciations in the central Andes.

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This chapter reviews the history of study and the current status of Mid-Holocene climatic and cultural change in the South Central Andes, which host a wide range of different habitats from Pacific coastal areas up to extremely harsh cold and dry environments of the high mountain plateau, the altiplano or the puna. Paleoenvironmental information reveals high amplitude and rapid changes in effective moisture during the Holocene period and, consequently, dramatically changing environmental conditions. Therefore, this area is suitable to study the response of hunting and gathering societies to environmental changes, because the smallest variations in the climatic conditions have large impacts on resources and the living space of humans. This chapter analyzes environmental and paleoclimatic information from lake sediments, ice cores, pollen profiles, and geomorphic processes and relates these with the cultural and geographic settlement patterns of human occupation in the different habitats in the area of southern Peru, southwest Bolivia, northwest Argentina, and north Chile and puts in perspective of the early and late Holocene to present a representative range of environmental and cultural changes. It has been found that the largest changes took place around 9000 cal yr BP when the humid early Holocene conditions were replaced by extremely arid but highly variable climatic conditions. These resulted in a marked decrease of human occupation, “ecological refuges,” increased mobility, and an orientation toward habitats with relatively stable resources (such as the coast, the puna seca, and “ecological refuges”).