La actividad turística es reconocida como motor del desarrollo en un territorio y una de las actividades que mayor impacto ha tenido en los últimos tiempos, en especial la práctica de turismo alternativo, más precisamente el termalismo. Surge de esta manera, la posibilidad de revalorizar el turismo en los distintos espacios e incorporarlo entre sus actividades. En la región objeto de estudio existen recursos tanto actuales como potenciales que posibilitan plantear la realización de una ruta turística termal en sudoeste de la provincia de Buenos Aires. El objetivo general de la investigación consiste en analizar posibles estrategias de desarrollo territorial en el sudoeste bonaerense a partir del turismo termal como instrumento de valorización local y regional. La propuesta vincula tres localidades: Pedro Luro, Médanos y Bahía Blanca; las dos primeras ya poseen centros termales en funcionamiento, mientras que Bahía Blanca, cuenta con los recursos apropiados así como la posibilidad de implementar un proyecto de inversión para desarrollar un complejo termal. Metodológicamente se aborda una estrategia tanto cualitativa como cuantitativa y la investigación se estructuró en instancias diferentes. Primero, se realizó una revisión bibliográfica de los conceptos relevantes, a los fines de que la propuesta sea sustentable y sostenible en el tiempo, buscando potenciar las capacidades internas de la región y las comunidades locales. Se realizaron relevamientos y trabajos de campo en cada nodo que conformaría la ruta termal con el fin de conformar un inventario de los recursos turísticos actuales y potenciales; se analizaron los componentes de la oferta y demanda turística; se realizaron entrevistas en las localidades de Médanos y Pedro Luro a los responsables o propietarios de los respectivos centros termales que posee cada una, así como a las autoridades de la municipalidad de cada distrito. Con los datos obtenidos se elaboró un índice de potencialidad turística en el área de análisis siguiendo la metodología propuesta por la Secretaría de Turismo de México (2010), así como un diagnóstico integral del espacio de estudio a través de un análisis FODA el cual permitió considerar las fortalezas, oportunidades, debilidades y amenazas de la incorporación del producto al mercado. Seguidamente se detectaron estrategias necesarias que se deberán adoptar para acentuar o atenuar los puntos fuertes y débiles, respectivamente. Finalmente, se realizó la conformación y diagramación de la ruta turística termal del sudoeste bonaerense y se aplicó la metodología de evaluación propuesta por la Consultora Desarrollo Turístico Sostenible (DTS), LTDA (2007). Los resultados obtenidos permitieron comprobar las hipótesis planteadas y, por lo tanto, se constata que las localidades de Bahía Blanca, Médanos y Pedro Luro, poseen recursos turísticos asociados al termalismo, culturales, naturales, urbanos, que permitirían conformar una ruta turística temática termal y diversificada. Por consiguiente, es posible afirmar que la creación de una ruta termal posibilitará alcanzar un mayor desarrollo socioeconómico en las localidades objeto de análisis, a partir de la valoración integral del territorio y de su patrimonio. / The tourist activity is recognized as an engine of development in a territory and one of the activities that has had the greatest impact in recent times, especially the practice of alternative tourism, more precisely thermalism. In this way, the possibility arises of enhancing tourism in the different spaces and incorporating it among their activities. In the region under study there are both current and potential resources that make possible the realization of a thermal tourist route in southwest of the province of Buenos Aires. The general objective of the research is to analyze possible strategies of territorial development in the southwest of Buenos Aires starting from the thermal tourism as instrument of local and regional valorization. The proposal links three localities: Pedro Luro, Médanos and Bahía Blanca; the first two already have thermal centers in operation, while Bahía Blanca, has the appropriate resources as well as the possibility to implement an investment project to develop a thermal complex. Methodologically, a qualitative and quantitative strategy is addressed and the research was structured in different instances. First, a bibliographical review of the relevant concepts was carried out in order to make the proposal sustainable and sustainable over time, with the aim of enhancing the internal capacities of the region and local communities. Surveys and field work were carried out on each node that would form the thermal route in order to form an inventory of current and potential tourist resources; the components of tourism supply and demand were analyzed; interviews were carried out in the localities of Médanos and Pedro Luro with the responsible persons or owners of the respective thermal centers that each has, as well as with the authorities of the municipality of each district. With the data obtained, an index of potential tourism in the area of analysis was prepared following the methodology proposed by the Ministry of Tourism of Mexico (2010), as well as an integral diagnosis of the study space through an SWOT analysis which allowed to consider the strengths, opportunities, weaknesses and threats of product incorporation to the market. Subsequently, necessary strategies were identified to be adopted to accentuate or mitigate strengths and weaknesses, respectively. Finally, the formation and diagramming of the thermal tourist route of southwest Buenos Aires was carried out and the evaluation methodology proposed by the Sustainable Tourism Development Consultancy (DTS), LTDA (2007) was applied. The results obtained allowed us to verify the hypotheses raised and, therefore, it is found that the localities of Bahía Blanca, Médanos and Pedro Luro, possess tourist resources associated with thermal, cultural, natural, urban, that would allow to form a thermal and diversified thematic tourist route. Therefore, it is possible to affirm that the creation of a thermal route will allow to reach a greater development.

Las cooperativas agrícolas ganaderas han sido por décadas un pilar fundamental principalmente para pequeños y medianos productores agropecuarios. Desde sus orígenes hasta la actualidad, el entorno en el que se desenvuelven ha sufrido modificaciones debido a los importantes cambios en los agronegocios. En este nuevo contexto en el que debieron desarrollar sus actividades, han surgido modificaciones en la gestión interna de este tipo de entidades. El objetivo de esta tesis es evaluar si se han dado cambios en las cooperativas agrícolas ganaderas; y en el caso de haber variaciones, captar las áreas o puntos en los que se presentan con mayor preponderancia. Por su condición socioeconómica y productiva, se circunscribirá en la región sudoeste de la Provincia de Buenos Aires como área de referencia. Además de definir conceptos centrales para el desarrollo de la tesis, se presentan apartados especiales que describen la evolución del sector agropecuario en Argentina, la evolución del cooperativismo en el país y la región sudoeste bonaerense, y las características específicas de la zona mencionada. Por otra parte, los referentes de la actividad fueron determinantes para agrupar entidades que luego se visitaron con el objetivo de captar modificaciones en su gestión interna. El trabajo de campo permitió clasificar las cooperativas de la región, sujetas a estudio, en grupos según los cambios en su gestión interna, pudiendo dilucidarse sobre cuáles aspectos se producen las mayores diferencias intergrupales. Al finalizar la investigación, puede concluirse que todas las cooperativas agrícolas ganaderas de la región sudoeste bonaerense han revelado variaciones, aunque lo han hecho de manera diversa. Mientras algunas presentan modificaciones que les permiten asimilarse a empresas de capital privado, otras intentan recuperar el funcionamiento que tenían las cooperativas tradicionales en tiempos anteriores. Palabras clave: Cooperativas agrícolas ganaderas, Gestión, Agronegocios, Sudoeste bonaerense. / Livestock agricultural cooperatives have been a mainstay for decades, mainly for the small and medium sized farmers. From its origins to recent times, the environment has suffered modifications due to the important changes in the agribusiness industry. This new context of business has resulted in a modification of the internal management of such entities. The objective of this thesis is to evaluate what fluctuations occur in livestock agricultural cooperatives and, in case that the cited variations have been taking place, establish the areas or points that arise as most preponderant. In order to discern in the socio-economic and production conditions, the analysis shall be limited to the southwest of Buenos Aires province as a reference area. In addition to the central concepts of the elaboration of the thesis, special sections describe the evolution of the agricultural sector in Argentina, the evolution of cooperative in the country and in the southwest region of Buenos Aires and the specific characteristics of the mentioned region. Moreover, the leaders of the activity were crucial to group entities that were later visited in order to capture changes in its internal management. The fieldwork allowed the classification of the cooperatives being analysed in the region, in groups according to their internal management, where you can elucidate what differences arise in the largest intergroup. Subsequently to the investigation, it can be concluded that all livestock agricultural cooperatives of the southwest of Buenos Aires revealed variations, although they have done it in different ways. Although private equity firms have taken over, others try to recuperate the management that the traditional cooperatives had in earlier times. Key words: Livestock agricultural cooperatives, Management, Agribusiness, Southwestern of Buenos Aires.

En el mercado actual resultan de interés los polímeros de estructura controlada, conocidos como especialidades. El método tradicional para obtenerlos, la polimerización iónica, requiere condiciones de alta pureza que dificultan en gran medida su implementación industrial. Una alternativa reciente está dada por los procesos de polimerización radicalaria controlada (CRP), que permiten obtener polímeros con características bien definidas bajo condiciones operativas y de pureza compatibles con la práctica industrial. Las características finales de los polímeros obtenidos por CRP dependen de un número importante de variables por lo que es deseable contar con una herramienta de cálculo que posibilite profundizar la comprensión de estos procesos de modo de facilitar su implementación práctica. En esta tesis se desarrollan modelos para procesos de CRP, en sus variantes polimerización mediada por nitróxidos (NMP) y polimerización por transferencia de cadena por adición-fragmentación reversible (RAFT). Se consideraron tanto homopolimerizaciones como copolimerizaciones. Los modelos emplean el método de los momentos y la técnica de las funciones generadoras de probabilidad (pgf), tanto univariables como multivariables. Los modelos desarrollados permiten predecir tanto las propiedades medias (tales como nM, wM y composición, entre otras) como calcular la MWD completa y la distribución de composición y de longitudes de secuencia en los copolímeros. Estos modelos fueron utilizados para simular polimerizaciones bajo diferentes condiciones operativas y en distintos tipos de reactor (batch, semibatch y tubular con alimentaciones laterales). Los resultados obtenidos permitieron establecer relaciones entre las condiciones de operación y la estructura molecular del material producido. Además se realizaron optimizaciones tendientes a la determinación de políticas operativas que condujeran a la producción de materiales con propiedades pre-determinadas. Los resultados muestran que las herramientas de cálculo desarrolladas tienen gran potencial para asistir en el desarrollo de materiales con propiedades pre-especificadas y en el estudio cinético de los procesos considerados. / Polymers with controlled structure, or specialty polymers, are of great interest in today’s market. The traditional method for obtaining them, ionic polymerization, requires such high standards of purity that it becomes almost impracticable in industrial settings. A recent alternative is provided by controlled radical polymerization processes (CRP), which allow obtaining polymers with well-defined characteristics under operating and purity conditions compatible with industrial practice. The final characteristics of polymers obtained by CRP depend on a large number of variables. Because of this it is desirable to have a modeling tool that allows increasing the comprehension of these processes and facilitates their practical implementation. In this thesis models for CRP processes are developed. Two variations of CRP are considered: nitroxide mediated polymerization (NMP) and reversible addition-fragmentation chain transfer polymerization (RAFT). Both homopolymerizations and copolymerizations were considered. The models use the method of moments and the probability generating function (pgf) technique, both univariable and multivariable. The models are able to predict not only average properties (such as nM, wM, and composition, among others) but they can also calculate the complete MWD, the composition distribution and the sequence length distribution. These models were used to simulate polymerizations under different operating conditions in different types of reactor (batch, semibatch and tubular with side feeds). The results allowed establishing relationships between the operating conditions and the molecular structure of the produced material. The models were also used in optimizations aiming at the determination of operating policies leading to the production of materials with pre-specified properties. The results show that the modeling tools developed in this thesis have great potential for assisting in the development of materials with pre-specified properties, and in the study of the kinetics of the processes under consideration.

El caracol Pomacea canaliculata (Caenogastropoda, Ampullariidae) es un habitante común de ambientes de agua dulce de la Ecorregión Pampeana. Este caracol, nativo de Sudamérica, ha alcanzado nuevas áreas fuera de su rango de distribución nativa. La expansión de esta especie, su establecimiento y la consecuente alteración ecosistémica han sido objeto de numerosas investigaciones y la han transformado en un interesante modelo de estudio. Los impactos, tanto en ambientes naturales como artificiales, han sido intensamente estudiados en regiones invadidas pero es escaso el conocimiento de su rol ecológico en su rango nativo, en particular el efecto que puede tener sobre otros macroinvertebrados. Los objetivos de esta tesis fueron comprender la influencia de P. canaliculata sobre las comunidades de macroinvertebrados bentónicos en humedales del Sudoeste Bonaerense (Buenos Aires, Argentina). Desde el punto de vista metodológico, esta tesis integra resultados experimentales en microcosmos de laboratorio y en mesocosmos al aire libre, así como experimentos y muestreos a campo. En microcosmos de laboratorio P. canaliculata redujo la supervivencia, la fecundidad y el uso del hábitat de varias especies de caracoles por efectos directos e indirectos. Los efectos predatorios pudieron ser detectados en caracoles de pequeño tamaño y sin opérculo y sobre sus masas de huevos gelatinosas. Sin embargo, la intensidad de las interacciones varió en cada especie. De igual manera, cada especie de caracol reaccionó ante el contacto con P. canaliculata de manera particular, expresando comportamientos de indiferencia, retracción o desplazamiento con distintas frecuencias. En ensayos en mesocosmos con vegetación acuática, P. canaliculata causó la disminución en la abundancia de varios taxa de macroinvertebrados, incluyendo varias especies de caracoles. Estos efectos estuvieron mediados mayoritariamente por la herbivoría del caracol que redujo la cobertura, biomasa y detritos de macrófitas. En contraste no se hallaron efectos sobre los macroinvertebrados de los sedimentos. Por lo tanto, en su rango nativo P. canaliculata puede interferir directamente en las tramas tróficas mediante la disminución de la abundancia de macrófitas y detritos. El estudio de la dieta natural de P. canaliculata a través del análisis de contenidos digestivos comprobó la ingesta de recursos de origen animal. Si bien no constituyen un componente mayoritario de su dieta, el consumo de macroinvertebrados y caracoles fue frecuente y abundante, siendo el caracol Heleobia parchappii la especie más consumida. En experimentos con sustratos artificiales en ambientes lóticos y lénticos, las comunidades de macroinvertebrados y de caracoles se vieron afectadas, dependiendo no solo de la presencia de P. canaliculata, sino también de su interacción con el tiempo de colonización. Pomacea canaliculata no parece influir en el proceso de colonización inicial, aunque su llegada sí afectó las comunidades recientemente establecidas. La llegada de P. canaliculata produce un aumento de algunos taxa como las larvas de coleópteros y la disminución de otros, como los caracoles, especialmente bajo condiciones lénticas. Comparando diversos sitios en distintos arroyos, se observaron correlaciones positivas significativas de las abundancias de P. canaliculata con las de los caracoles H. parchappii y Chilina parchappii, pero no para los otros taxa de macroinvertebrados. Esto podría deberse a requerimientos ambientales comunes de las tres especies de caracoles o a interacciones de facilitación por coprofagia. Los efectos de las interacciones con P. canaliculata dependen de cada especie de macroinvertebrado, pudiendo favorecer a unas y perjudicar a otras. En el caso de caracoles exóticos, P. canaliculata puede limitar su establecimiento y mitigar su dispersión. Sin embargo, en áreas invadidas P. canaliculata podría facilitar a otras especies no nativas, aumentando las probabilidades de invasión y el impacto ecológico. En conclusión, P. canaliculata ejerce un papel clave en los ambientes de agua dulce, no solo regulando con su herbivoría a las macrófitas acuáticas que ofrecen refugio y alimento a otros macroinvertebrados, sino también por los efectos directos de su depredación e interferencia. / The apple snail Pomacea canaliculata (Caenogastropoda, Ampullariidae) is a common inhabitant of freshwater environments of the Pampean Ecoregion. This apple snail, native to South America, has reached many new areas outside its native range. The expansion of this species, its establishment and the consequent ecosystem alterations, have been the subject of extensive research and have transformed the species into an interesting study model. Its impacts, both in natural and artificial environments, have been intensively studied in invaded regions but there is little knowledge of its ecological role in its native range, in particular the effect that it may have on other macroinvertebrates. The aim of this thesis was to understand the influence of P. canaliculata on the benthic macroinvertebrate communities in wetlands of Buenos Aires (Buenos Aires, Argentina). From a methodological point of view, this thesis integrates experimental results from laboratory microcosms with those from outdoor mesocosms, as well as experiments and field sampling. In laboratory microcosms P.canaliculata reduced the survival, fertility and habitat use of several snail species through direct and indirect effects. Predatory effects were detected on small sized snails without operculum and on their gelatinous egg masses. However, the intensity of the interactions varied among species. Similarly, each species of snail reacted in a particular way to contacts with P. canaliculata, showing indifference, retraction or displacement behaviours with different frequencies. In experimental mesocosms with aquatic vegetation, P. canaliculata caused a decrease in the abundance of several macroinvertebrate taxa, including several species of snails. These effects were mostly mediated by the apple snail’s herbivory that reduced macrophyte coverage, biomass and detritus. In contrast, there were no effects on the macroinvertebrates of the sediments. Therefore, in its native range P. canaliculata can interfere with trophic webs by decreasing the abundance of macrophytes and their detritus. The study of the natural diet of P. canaliculata through the analysis of digestive contents verified the ingestion of resources of animal origin. Although they do not constitute a major component of their diet, the consumption of macroinvertebrates and snails was frequent and abundant, with the snail Heleobia parchappii being the most consumed species. In experiments with artificial substrates in lotic and lentic environments, macroinvertebrate and snail taxa were affected, depending not only on the presence of P. canaliculata, but also on its interaction with colonization time. Pomacea canaliculata does not seem to influence the initial colonization process, although its arrival did affect recently established communities. The arrival of P. canaliculata produces an increase of some taxa such as beetle larvae and the decrease of others, such as snails, especially under lentic conditions. In a sampling scheme comparing various sites in different streams in southwestern Buenos Aires province, significant positive correlations were observed between the abundance of P. canaliculata and those of the snails H. parchappii and Chilina parchappii, but not for the other macroinvertebrate taxa. This could be due to common environmental requirements of the three species of snails or to facilitation interactions through coprophagy. The effects of the interactions with P. canaliculata depend on each macroinvertebrate species, being able to promote some and to hinder others. In the case of exotic snails, P. canaliculata can limit their establishment and mitigate their dispersion. However, in invaded areas P. canaliculata could favour other exotic species, increasing the likelihood of invasion and ecological impacts. In conclusion, P. canaliculata plays a key role in freshwater environments, not only regulating with its herbivory the community of aquatic macrophytes that offer shelter and trophic resources to other macroinvertebrates, but also by direct the effects like of direct predation and interference.

El desarrollo de tecnología agropecuaria involucra actores de todas las disciplinas cientícas, principalmente de las ciencias naturales, seguido por las ciencias formales y en menor medida, las ciencias humanas o sociales. Es a partir de la colaboración interdisciplinaria de distintos grupos de investigación que permitió la elaboración del presente trabajo, en el cual se abordan diversas cuestiones respecto de la incorporación de sistemas computacionales con distintas funcionalidades y características en pos de brindar soporte a las actividades agropecuarias, particularmente aquellas que predominan en el sector del Sudoeste de la Provincia de Buenos Aires. Se intenta cubrir los aspectos m as relevantes referidos al diseño e implementación de dichos sistemas, desde un punto de vista técnico y con un especial enfoque hacia el empleo de metodologías de diseño con cierto grado de optimalidad. El eje central de la tesis se divide en tres partes con la finalidad de separar las problemáticas relacionadas a la adquisición, transmisión y el análisis o procesamiento de los datos. En la cuarta y ante ultima parte de este trabajo, se integran los conceptos anteriormente expuestos y se exploran las arquitecturas donde interactúan sistemas m as complejos del que forman parte tanto las máquinas como las personas. Dentro de este ultimo grupo se engloban los sistemas colaborativos, para los cuales se analizan dos propuestas diferentes, con un enfoque hacia los aspectos de comunicación por un lado y por el otro, el diseño de un sistema que tiene el objetivo de mejorar cuestiones de logística en el sector agropecuario, especialmente en zona rural. / The development of agricultural technology involves actors from all scienti c disciplines, mainly from the natural sciences, followed by the formal sciences and to a lesser extent, the human or social sciences. It is from the interdisciplinary collaboration of different research groups that allowed the accomplishment of this work, in which certain issues are addressed regarding the incorporation of computer systems with different functionalities and characteristics in order to provide support to agricultural activities, particularly those that predominate in the Southwest sector of the Buenos Aires Province. It is intended to cover all technical aspects related to the design and implementation of said systems, from a technical point of view and with a special focus on the use of design methodologies with a certain degree of optimality. The central axis of the current thesis is divided into three parts in order to separate the problems related to the data acquisition, transmission and analysis or processing. In the fourth and penultimate part of this work, the previously exposed concepts are integrated and the architectures where more complex systems interacts, of which both machines and people are part, are explored. Collaborative systems are included in this last group, for which two different proposals are analyzed, with a focus on communication aspects on the one hand and on the other, the design of a system that aims to improve logistics issues in the agricultural sector, especially in rural areas.

El desarrollo de la actividad apícola en el sudoeste bonaerense es de larga data. Sin embargo, los avances asociativos logrados en materia productiva no han tenido su correlato en el terreno comercial. El objetivo principal del presente trabajo es definir los puntos críticos que deben existir en los modelos de comercialización conjunta para pequeños y medianos productores, para que los mismos cumplan con condiciones de eficiencia y sostenibilidad a lo largo del tiempo. Como hipótesis de trabajo, se estableció que los pequeños y medianos productores apícolas del sudoeste bonaerense no logran captar mayores beneficios en la comercialización porque los modelos asociativos vigentes entran en conflicto con características de los individuos involucrados, con el tipo de producto comercializado y con las relaciones organizacionales dominantes. Como marco conceptual de análisis se utilizó el enfoque de Sistemas Agroalimentarios Localizados (SIAL). A través de un completo diagnóstico que incluyó el mercado mundial de la miel, el análisis de la estructura del sector apícola a nivel nacional y regional, entrevistas a informantes claves y estudios de casos, se arribó a la conclusión que los principales puntos críticos que deben contener los esquemas asociativos para lograr ser eficientes y sustentables en el tiempo son el grado de empresarialidad del productor, la disminución de la incertidumbre, los negocios profesionalizados y la gestión de la información. En base a éstos, se confeccionó una propuesta denominada: “Red de grupos vinculados entre sí a través de las salas de extracción que comercializan por contratos validados por la Cámara Arbitral de Cereales”, la cual consiste básicamente en conformar una red de pequeños grupos (formales o no) vinculados a través de las salas donde extraen su miel, utilizando un sistema de contratos internos y externos para reducir la incertidumbre. Para el diseño del modelo, se utilizaron aportes de las teorías de la acción colectiva (Olson) y de contratos (Hart y Holmström). Finalmente, se realizó una simulación de los resultados económicos logrados por la utilización de la propuesta, destacando los logros y los cuellos de botella para su adopción. Se espera que esta tesis contribuya en tal sentido, al menos como disparador de ideas y críticas constructivas, no sólo para posicionar a la apicultura del sudoeste bonaerense en los primeros puestos de innovación organizacional, sino fundamentalmente para mejorar la calidad de vida de los habitantes de una región postergada en cuanto a su desarrollo económico, tanto por cuestiones climáticas como por políticas centralistas implementadas durante décadas. / The development of beekeeping in the south-east of Buenos Aires is long-standing. However, the associative advances achieved in production have not had their correlation in commercialization. The main goal of this thesis is to define the critical points that should exist in joint commercialization models for small and medium producers, in order to fulfill conditions of efficiency and sustainability over time. As a working hypothesis, it was established that the small and medium-sized beekeepers do not manage to gain greater benefits in marketing because the existing associative models get in conflict with the characteristics of the individuals involved, the type of product commercializated and the main organizational relationships. Focusing on conflicts and critical points, an overcoming proposal was presented for the strengthening of the mass of beekeepers and the positive consequences that this would bring in the area. The Localized Agri-Food Systems (LAFS) approach was used as a theoretical framework, which made a great contribution to the understanding of the problems and the importance of generating innovative short, medium and long-term solutions. Through a thorough diagnosis that included the global honeymarket, analysis of the structure of the beekeeping sector at national and regional levels, interviews with key informants and case studies, it could be concluded that the main critical points that associative schemes should contain in order to be efficient and sustainable over time are the degree of entrepreneurship of the beekeper, the reduction of uncertainty, professional business and information management. On account of all these, a proposal was made: "Network of small groups linked to each other through the extraction rooms trading by contracts validated by an Arbitral Chamber", which basically consists of developing a network of small groups (formal or not) linked to each other through the places where they extract their honey, using a system of internal and external contracts to reduce uncertainty. For the design of the model, contributions from theories of collective action (Olson) and contracts (Hart and Holmström) were used. Finally, a simulation of the economic results obtained by the use of the proposal was made, highlighting the achievements and the bottlenecks for its adoption. It is hoped that this thesis will contribute in this sense, at least as a trigger of ideas and constructive criticism, not only to place beekeeping of the south-east of Buenos Aires in the first positions of organizational innovation, but mainly to improve the life quality of the inhabitants of a neglected region in terms of economic development, mainly because of climate issues and centralist policies implemented for decades.

O conhecimento da paleoceanografia do Oceano Atlântico Sul tem aumentado nas últimas décadas, porém ainda são raros os trabalhos sobre o Atlântico Sudoeste que utilizam dados de proxies de condições redox de massas d\'água, relacionados às mudanças climáticas entre os períodos Pleistoceno superior e Holoceno. Diante disso, esta Dissertação de Mestrado avaliou as condições redox das águas intermediárias do Atlântico Sudoeste nos últimos 40 mil anos. Este trabalho fez estudos de proxies geoquímicos - de condições redox (V/Sc, V/Cr, V/Al, Mn/Al e Ni/Co), de aporte de sedimentos terTMTMrígenos (Fe/Ca e Ti/Ca), de produtividade (COT, CaCO3) e origem da matéria orgânica (δ13C e C/N) - em um registro sedimentar marinho coletado na região do talude continental da margem sudeste brasileira, e os relacionou com as mudanças da Célula de Revolvimento Meridional do Atlântico (sigla em inglês AMOC - Atlantic Medirional Overturning Circulation) e com os principais eventos climáticos em escala orbital, como o Último Máximo Glacial, e de escala milenar, como os eventos tipo Heinrich Stadials, Younger Dryas e 8.2. Os resultados demonstram que, nos últimos 40 mil anos, as águas intermediárias que banham a costa sudeste brasileira apresentam níveis óxicos, o que classifica o ambiente como oxidante, porém foi possível observar variações na quantidade de oxigênio dissolvido nessas águas durante determinados eventos climáticos, bem como variações no aporte de sedimentos terrígenos e na produtividade. Em escala orbital a insolação de verão do Hemisfério Sul e a variação do nível do mar, governadas pelo ciclo de precessão, apresentam-se como os principais mecanismos que influenciam essas variações. Em escala milenar a variabilidade da AMOC apresenta-se como o principal mecanismo responsável por essas variações. Dentre os eventos climáticos de escala milenar, o evento 8.2 demonstrou complexa variabilidade nas condições redox das águas intermediárias do Atlântico Sudoeste, uma vez que, durante sua ocorrência, observamos aumento das concentrações de oxigênio dessas águas e baixos valores de produtividade. / The interest in the paleoceanographic history of the South Atlantic Ocean has increased in the last decades, however there are still few studies regarding the redox conditions of the intermediate water masses of the Southwest Atlantic and their relationship to the climatic changes during the upper Pleistocene and Holocene. Within this context, this work aims to evaluate the redox conditions of the intermediate waters of the Southwest Atlantic in the last 40 ka. For this, geochemical proxies - of redox conditions (V/ Sc, V/ Cr, V/ Al, Mn/ Al and Ni/ Co), of terrigenous sediments supply (Fe/ Ca and Ti/ Ca), of productive (COT, CaCO3), and organic matter source (δ13C and C / N) - were applied to marine sediments from a core collected on the continental slope of the Brazilian Southeastern margin and then related it to changes in the Atlantic Meridional Overturning Circulation (AMOC) and with the main cold climatic events of North Atlantic, such as the Last Glacial Maximum and millennial scale, such as events type the Heinrich Stadials, Younger Dryas and 8.2. Our results show that, over the last 40,000 years, the redox conditions of the intermediate waters of the Brazilian Southeast margin present oxic levels, which classifies the environment as oxidant, however, variations was noticed in the amount of oxygen dissolved in these waters influenced by certain climatic events, as well as changes in the input of terrigenous sediments and in the productivity. In orbital scale, the summer insolation of the Southern Hemisphere and the variation of sea level, leaded by the cycle of precession, are presented as the main mechanisms that influence these variations. On the other hand, at millennia scale, the AMOC variability is the main mechanism responsible of these variations. Among the climate events at millennia scale, the event 8.2 demonstrated a complex variability of the redox conditions of the intermediate waters of the Southwest Atlantic, once during its occurrence we observed increase concentrations of oxygen in these waters and a decrease of productivity.

O papel do Oceano Atlântico Sul na manutenção do clima global é de extrema importância uma vez que compõe uma das partes fundamentais da circulação Termohalina Global. Nesse contexto, o Sudoeste do Atlântico Sul é uma região complexa e energética, onde duas correntes de contorno oeste de sentidos opostos se encontram formando a Confluência Brasil-Malvinas. O objetivo deste trabalho é investigar mudanças de longo período na variabilidade da latitude de separação da Corrente do Brasil (CB) da Plataforma Continental, considerada um delimitador do limite sul do Giro Subtropical do Atlântico Sul na região do Sudoeste do Atlântico Sul. Para tal, foi usado resultados do modelo HYCOM em um experimento datado denominado ATIa0,25. O modelo foi forçado por dados da reanálise do NCEP e seus resultados abrangem o período de 1960 a 2010. A latitude de separação da CB da costa foi definida neste trabalho como o ponto em que a isoterma de 18°C cruza a isóbata de 1000 metros de profundidade. A variabilidade da latitude de separação da CB pode ser dividida em três momentos principais: no começo a latitude de separação está ao sul de sua média, na década de 70 está a norte de sua posição média até a década de 90; depois dos anos 90 a posição começa a se deslocar para sul até 2010. As tendências encontradas são 0,37 ± 0,02°/década entre 1960 e o final da década de 70 e 0,10 ± 0,01°/década de 1980 a 2010. Os transportes das correntes do Brasil e das Malvinas, as latitudes dos rotacionais nulo e máximo do vento e o índice do Modo Anular Sul são também analisados no período de 1960 a 2010, como possíveis forçantes da variação da latitude da separação da CB. Todas a séries obtidas apresentam mudança ao intensificação das tendências entre as décadas de 70 e 80 - assim como na série de separação da CB. Esse comportamento pode estar relacionado ao Modo Anular Sul. Este modo de variabilidade climática afeta as forçantes de separação da CB em escalas de tempo diferentes. O deslocamento para sul do limite sul do Giro Subtropical do Atlântico Sul observado nesse trabalho inicia-se no início da década de 90 e está relacionado com mudanças nos regimes de vento da bacia causadas provavelmente por mudanças nos campos de temperatura de superfície do mar. / The role of South Atlantic Ocean on global climate is highly important since it compounds one of the most significant parts of Thermohaline Circulation, the Atlantic Meridional Overturning Circulation. In this sense, the Southwestern South Atlantic is a complex and energetic region, where two western boundary currents, coming in opposite directions, encounter each other forming the Brazil-Malvinas Confluence. The goal of this work is to investigate long-term changes in the latitude of separation of the Brazil Current, considered as the southern limit of the South Atlantic Subtropical Gyre in the Southwestern South Atlantic. In this investigation, results of a numerical experiment with the model HYCOM, dubbed ATIa0.25, were used. The model was forced with NCEP reanalysis products and its results cover the period of 1960 to 2010. The Brazil Current separation latitude was defined as the point where the 18°C isotherm crosses the 1000 meters depth isobath. The variability of the CB separation latitude can be divided in three periods: at the beginning of experiment, the separation point has a tendency to move southward of it\'s mean position; From the 70\'s to the 90\'s, it shows a northward tendency; after the 90\'s it started again a southward shift until 2010. The trends of the northward shifts are of 0.37 ± 0.02°/decade in the 70\'s and 0.10 ± 0.01°/decade between 80\'s and 2010\'s. Brazil and Malvinas currents transports, the latitude of zero and maximum value of the wind stress curl and the Southern Annular Mode index are also analyzed for the 1960-2010, period as possible forcing mechanisms of BC separation latitude. All series obtained presents changes or intensification on trends between 70\'s and 80\'s decades - so do the series of BC separation latitude. This behavior can be related to the Southern Annular Mode. This climatic mode of variability affects the forcing mechanisms of the BC separation latitude in different time scales. The southward shift of the southern limit of South Atlantic Subtropical Gyre observed in this work starts in the beginning of 90\'s decade and is related with changes in wind patterns, probably due to changes in sea surface temperature distribution.

O Atlântico Sudoeste comporta uma das regiões oceânicas mais energéticas do planeta: a Confluência Brasil-Malvinas (CBM). Essa região encerra o giro subtropical do Atlântico Sul e possui fundamental importância para a dinâmica desse oceano bem como para o clima regional. Através de saídas de modelos numéricos acoplados do 4°?elatório do IPCC, descreve-se o comportamento dessa região em dois cenários futuros de aquecimento global: um de elevada emissão de gases estufa (A1b) e o outro mais ameno em termos de impactos antrópicos (B2). Ambos os cenários apresentaram fortes tendências de aumento de temperatura sobretudo na superfície (chegando a 0,065°C/ano no cenário A1b e 0,055°C/ano no B2). A salinidade de superfície mostrou forte tendência positiva do Equador até a região da CBM, e negativa em maiores latitudes. A posição média da CBM desloca-se em aproximadamente 1,1° para sul no cenário A1b (entre 2066 e 2100) e 0,9° no cenário B2. O padrão espectral dessa posição (dominado pelo ciclo anual no século XX) é dominado pela variabilidade de baixa frequência no cenário A1b. Tais modificações na média e no espectro da posição da CBM estão associados à intensificação e mudança da Corrente do Brasil. / Southwestern Atlantic comprises one of the most energetic region of the world: Brazil-Malvinas Confluence (BMC). This region lies within the Southern Atlantic Subtropical Gyre and holds fundamental importance for this oceanic dynamics as well as for the regional climate. Through numerical modeling output coupled to IPCC\'s 4th Report, it is sunk to describe this region behavior for two distinct future scenarios: high greenhouse gases emission (A1b) and a milder one in terms of anthropic impacts (B2). Both scenarios have shown strong temperature increasing tendencies, especially on the surface (reaching up to 0.065°C/year in A1b and 0.055°C/year in B2). Surface salinity have also shown strong positive tendency from the Equator to the BMC region, and negative in higher latitudes. BMC medium position is shifted around 1.1°S in A1b scenario (between 2066 and 2010) and 0.9° in B2. Spectral pattern on this position (dominated for XX century annual cycle) is controlled by low-frequency variabilities in A1b scenario. These modifications in average and spectral patterns of BMC position are linked to the intensification and changing of Brazil current.

Made available in DSpace on 2016-08-10T10:53:28Z (GMT). No. of bitstreams: 1 Henrique Santana Costa.pdf: 8354226 bytes, checksum: 5a89dbe7cdf1985aa143e4e6c6e496a0 (MD5) Previous issue date: 2009-03-09 / The geochemical responses of the environment are controlled first by natural geologic, pedologic, climatic, and biological processes. Superimposed on these natural influences, human activity plays an important role due to the possibilities of alteration of the geochemical environment caused by urban centers, as well as by industrial and agricultural activities. Multielemental geochemical surveys show their discriminatory capacity to research the geographical relationship among distribution of chemical elements, natural patterns, and anthropogenic alterations. In this study, we monitored the quality of water intended for human consumption in the 18 municipalities of the Southwestern micro-region of the state of Goiás, Brazil. Water samples collected in the Water Treatment Plants (WTPs) underwent multielemental chemical analyses (ICP OES method) in order to correlate the obtained data to waterborne diseases that can pose a threat to human health. Using the results of these analyses, we built up a correlation matrix (defining geochemical associations) and maps of chemical elements distribution. The integrated analysis of these data revealed the presence of high concentrations (values of 1st, 2nd, and 3rd order) of the elements Fe, Pb, Zn, as well as NO3 in the water samples collected in the WTPs of Aparecida do Rio Doce, Chapadão do Céu (artesian well), Jataí, and Mineiros. We also visited the Health Secretary of the state of Goiás aiming to collect as many epidemiological data as possible for the region under study. All the information collected is going to be included in DATASUS, SEPLIN/GO, and SVS/MS database. The importance of this study lies in the possibility of employing it as an instrument to release information using geoprocessing tools and searching for the incorporation of new technological, human, and logistic means to develop a policy for funding financial and material resources in order to achieve the effective decentralization of actions on health in the state of Goiás, as well as to establish priorities and strategies to enhance the health policy in the region under study. / As respostas geoquímicas do ambiente são controladas, em primeiro lugar, pelos processos naturais, geológicos, pedológicos, climáticos e biológicos. Superpondo-se a essa herança, a presença do homem adquire papel importante pelas possibilidades de alteração que promove no ambiente geoquímico a partir de concentrações urbanas, atividades industriais e agrícolas. Na investigação dos relacionamentos geográficos da distribuição de elementos químicos com as feições naturais e as alterações antrópicas, a geoquímica multielementar apresenta-se como instrumento de grande capacidade de discriminação. No presente trabalho, verificou-se a qualidade da água consumida pela população dos 18 municípios que compõem a microrregião sudoeste do Estado de Goiás, Brasil. Foram realizadas análises químicas multielementares (método ICP OES) do material coletado nas Estações de Tratamento de Água (ETAs) procurando correlacionar os dados obtidos com possíveis doenças que afetem a saúde humana. A partir dos resultados encontrados, foi construída uma matriz de correlação (definindo as associações geoquímicas) e mapas de distribuição dos elementos químicos. A análise integrada dos dados revelou a presença de altas concentrações (valores de 1ª, 2ª e 3ª ordem) dos elementos químicos Fe, Pb, Zn, bem como de NO3 nas amostras de água coletadas nas ETAs dos municípios de Aparecida do Rio Doce, Chapadão do Céu (poço artesiano), Jataí e Mineiros. Foram realizadas visitas à Secretaria de Estado de Saúde de Goiás com o objetivo de angariar o maior número possível de pareceres relativos ao quadro epidemiológico da região trabalhada. As informações apuradas serão adicionadas à base de dados do DATASUS, SEPLIN/GO e SVS/MS. Ressaltase a importância deste estudo como instrumento de divulgação de informações utilizando geoprocessamento e buscando incorporar novos meios tecnológicos, humanos e logísticos para o desenvolvimento de uma política de captação de recursos financeiros e materiais de modo a atingir efetiva descentralização das ações de saúde no Estado de Goiás, bem como estabelecer prioridades e estratégias visando melhorar a política de saúde das regionais analisadas.