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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Repensando a integração sul-americana

Araujo, Assilio Luiz Zanella de January 2013 (has links)
Esta dissertação tem um propósito ambicioso: procura repensar o modelo de integração econômica na América do Sul. O método escolhido para tanto foi o de analisar e extrair lições de outras experiências de integração econômica para balizar uma reflexão sobre este processo na região. Neste sentido, dividiu-se a dissertação em três capítulos, além de um breve capítulo introdutório e das considerações finais. No capítulo 2, “Considerações Gerais e Teorias sobre Integração Econômica Regional”, realiza-se apenas algumas definições conceituais e uma breve revisão das teorias sobre integração econômica regional. O intuito deste capítulo inicial é tão somente de “limpar o terreno” para a análise dos capítulos posteriores. Feito isso, no capítulo 3, “Lições das Experiências Internacionais Recentes: União Monetária Europeia, NAFTA e Cooperação Financeira no Leste Asiático”, analisa-se as principais experiências internacionais de integração, apresentando basicamente a racionalidade, a lógica básica de funcionamento e os resultados alcançados por cada uma delas, de tal forma a depreender algumas lições para a América do Sul. No capítulo 4, “Lições das Iniciativas Pretéritas de Integração na América do Sul: Uma Breve Análise do Caminho Percorrido da ALALC à UNASUL”, apresenta-se um apanhado histórico das iniciativas de integração econômica na América do Sul, seguindo essencialmente a mesma estrutura do capítulo anterior. Por fim, nas considerações finais, à luz das lições extraídas nos capítulos anteriores, são tecidos alguns comentários sobre as iniciativas integracionistas vigentes na região. / The dissertation has an ambitious intention: it aims at rethinking the model of economic integration in South America. The method chosen for such task was to analyze and extract lessons of other experiences of economic integration to define a reflection regarding this process in the region. In this direction, the dissertation was divided into three chapters, along with a brief introductory chapter and the final considerations. Chapter 2, “General Considerations and Theories on Regional Economic Integration”, presents some conceptual definitions and a brief revision of the theories on regional economic integration. The intention of this initial chapter is mainly to “clear the ground” for the analysis of the subsequent chapters. Once this is done, in chapter 3, “Lessons of the Recent International Experiences: European Monetary Union, NAFTA and Financial Cooperation in the East Asian”, the main international experiences of integration are analyzed, presenting basically the rationality, the basic logic of functioning and the results reached by each one of them, in such way to infer in the end some lessons for South America. Chapter 4, “Lessons of the Past Initiatives of Integration in South America: a Concise Analysis of the Way from ALALC to UNASUL”, presents a historical summary of the initiatives of economic integration in South America, following, essentially, the same structure of the previous chapter. Finally, in the final considerations, in light of the lessons extracted in the previous chapters, some comments are made on the effective integrationist initiatives in the region.
52

Differential expression of recent gene duplicates in developmental tissues of <i>Arabidopsis thaliana</i>

Owens, Sarah Marie 14 August 2009 (has links)
No description available.
53

Skapelsen : En studie om presentationen av skapelseberättelser i läromedel på 1960-, 1990 och 2000-talet. / The creation : A study on the presentation of creation stories in teaching materials in the 1960s, 1990s and 2000s.

Rangsjö, Nadia January 2015 (has links)
I detta examensarbete undersöker jag hur de två första skapelseberättelserna i Bibeln samt skapelseberättelserna i den babyloniska och kanaáneiska mytologin skildras i läromedel på 1960-, 1990- och 2000-talet. Syftet med studien var att undersöka hur skapelseskildringarna i första Mosebok skildras i läromedlen samt om de jämförs med tidigare skapelseberättelser i Främre Orienten. Studien syftade även till att se huruvida det skett förändringar i skildringen under årtiondena. I min bakgrund kommer jag först att presentera en överblick över den samhälleliga och religiösa kontexten som de människor i den dåtida främre orienten verkade i. Då detta är tillkomstområde för skapelseberättelserna i Enuma Elish, den kanaáneiska mytologin och Genesis syftar min presentation till att lättare kunna förstå hur de kan ha påverkat varandra. Metoden jag valde att använda är en komparativ kvalitativ analys av tre läromedel från 1960-talet, tre från 1990-talet och tre från 2000-talet. Resultatet har därefter presenterats i enlighet med den systematiserande undersökningsmetod jag har använt mig av. Syftet med den systematiserande undersökningen var att få en tydlig översikt över möjliga förändringar men även för att på ett enkelt sätt kunna behandla resultatet. Studiens resultat visade att läromedel på 1960-talet hade tydligare skildring och mer historiskt innehåll, medan på 1990-talet skildras den bibliska skapelsen mer som en saga med få texter om den historiska bakgrunden. Fokus i läromedel på 2000-talet låg på att skildra syftet med skapelseberättelserna mer än dess innehåll. / In this essay, I examine how the first two creation stories in the Bible and creation stories of the Babylonian and Canaanean mythology are portrayed in the teaching materials in the 1960s, 1990s and 2000s. The purpose of the study was to investigate if the creation stories in Genesis are mentioned in the school textbooks and if they are compared with earlier creation stories in the Near East. The study also aimed to see whether there have been changes in the portrayal over the decades. In my background, I will first present an overview of the social and religious context in which the people of the contemporary Near East lived in. As this is the geographical area of origin for the creation stories in the Enuma Elish, the Canaanean mythology and Genesis, the purpose of my background presentation is to make it easier to understand how they may have influenced each other. The method I chose is a comparative qualitative analysis of three teaching materials from the 1960s, three from the 1990s and three from the 2000s. The result is then presented in accordance with the systematizing research method I have used. The purpose of systematizing the survey was to get a clear overview of possible changes, but also as an easy way to process the results. The study results showed that the study materials in the 1960s had clearer depiction and more historical content, while in the 1990s the biblical creation are more described like a fairy tale, with few texts about the historical content. The focus of the study materials in the 2000s was on portraying the purpose of the creation stories over the content.
54

"Det är klart att jag känner mig stressad hela tiden" : En kvalitativ jämförande studie om nyutexaminerade och erfarna socialsekreterares arbetsrelaterade stress inom  socialtjänsten / It is clear that I feel stressed all the time : A qualitative comparative study of graduates and experienced social secretary work-related stress in social services

Engström, Ellen, Hjelm, Erika January 2016 (has links)
Syftet med denna studie är att undersöka hur nyutexaminerade och erfarna socialsekreterare upplever sin nuvarande arbetsroll inom socialtjänsten. Tidigare forskning visar att stöd från arbetsgivaren och erfarenhet är två viktiga aspekter för hur socialsekreterare hanterar sitt arbete. De teoretiska utgångspunkterna för studien är ”krav- och kontrollmodellen” samt ”coping”. Med dessa teorier kan vi få en större förståelse för strukturer och individens egna strategier för att hantera krävande arbetssituationer. Studien utgörs av en kvalitativ ansats med sex semistrukturerade intervjuer med personer som arbetar inom socialtjänsten. Resultatet visade att erfarenhet inte behöver betyda att man har den bästa copingstrategin eller förmågan att hantera pressade arbetssituationer. Hantering av krav var det som var viktigast för att klara av att arbeta under pressade arbetsförhållanden. Slutligen konstaterar vi att både de nyutexaminerade och erfarna socialsekreterarna använder sig av känslomässig- och problemfokuserad coping. De som använde sig av problemfokuserad coping var de som kunde lämna arbetet utan att tänka på sina klienter under sin fritid. / The purpose of this study is to investigate how graduates and practiced social workers experience their current job in social services. Previous research shows that support from the employer and previous job experience are two important aspects of how social workers deal with their work. The theoretical basis for the study is ”demand- control model” and  ”coping ". With these theories, we can gain a greater understanding of the structures and the individual's own strategies for dealing with demanding work situations. The study consists of a qualitative approach with six semi-structured interviews with people working in the social service sector. The result showed that the experience does not necessarily mean that you have the best coping strategy or the ability to handle stressful work situations. Being able to manage set standards and demands was of most importance when working under stressful conditions. Finally, we noticed that both the newly graduated and the experienced social workers use emotional- and problem focused coping. Those who used problem focused coping were those who could be off work and not think about their clients.
55

Enregistrement molécularie de changements d'usage des sols et de pressions anthropiques : l'exemple d'un étang piscicole (Lansquenet, Lorraine) / Molecular record of land use changes and anthropogenic pressure : example of a fish pond (Lansquenet, Lorraine)

Bertrand, Olivia 12 October 2012 (has links)
Les séries sédimentaires, prélevées dans les écosystèmes aquatiques terrestres, constituent des enregistrements ou des archives de l'état d'un système à un instant donné du passé et de son évolution en relation avec la variabilité environnementale naturelle et anthropique. Dans le cadre de cette thèse, l'enregistrement sédimentaire d'un étang piscicole, a été étudié suivant une approche pluridisciplinaire. En particulier, la caractérisation à l'échelle moléculaire et macromoléculaire de la matière organique des sédiments de l'étang de Lansquenet a permis de reconstruire l'histoire de son bassin versant. Basé sur l'utilisation de biomarqueurs et de rapports moléculaires (rapport terrigène/aquatique : TAR(HC), C29/C27(ST), aquatic/macrophyte proxy : Paq, pérylène, syringyle/vanillyle, cinnamyle/vanillyle, acide/aldéhyde des unités syringyles et vanillyle), ce travail a permis d'appréhender, à l'échelle d'un bassin versant, les variations pluriséculaires des sources de la matière organique (terrestre et/ou aquatique, naturelle et/ou anthropique), mais aussi des conditions de dépôt et de préservation, induits par les changements d'usage des sols et les impacts anthropiques. La confrontation de ces résultats avec les données sédimentologiques, minéralogiques et palynologiques a permis de valider la pertinence et la sensibilité de ces biomarqueurs par rapport aux variations environnementales et paléoenvironnementales. Cette étude met ainsi en évidence la succession des usages de ce site depuis un milieu marécageux jusqu'à la création et l'exploitation de l'étang piscicole jalonnée d'épisodes d'assec / The sedimentary series, collected in terrestrial and aquatic ecosystems, constitute records or archives of the state of a system at a given moment of the past and relate its evolution in relation to natural disturbances and anthropogenic pressure. In the following manuscript, the sedimentary record of a fish pond has been studied using a multidisciplinary approach. In particular, the characterization at the molecular and macromolecular scale of the organic matter in sediments of the pond Lansquenet allowed to reconstruct the history of its watershed. On the basis of biomarkers and molecular ratios (terrestrial to aquatic ratio: TAR(HC), C29/C27(ST), aquatic/macrophyte proxy: Paq, perylene, syringyl/vanillyl, cinnamyl/vanillyl, acid/aldehyde of syringyl and vanillyl units), this work has enabled us to understand, at the scale of a watershed, the changes in organic matter origins (terrestrial and/or aquatic, natural and/or anthropogenic) over a period of several centuries. Moreover, the results unraveled the depositional conditions as well as preservation conditions in the sedimentary profile, directly influenced by land use and human activities. The confrontation of organic geochemical data with sedimentological, mineralogical and palynological data was a real benefit and validated the use of a series of organic compounds as relevant and sensitive biomarkers regarding environmental and paleoenvironmental modifications. This study highlighted thus the succession of use of the Lansquenet site from a swampy area to the settlement of a fish pond punctuated by drier periods
56

Occurrence des pesticides et des contaminants émergents dans une nappe alluviale. Contraintes apportées par l’origine et le temps de résidence de l’eau. Cas de la nappe de la Vistrenque / Occurrence of pesticides and emerging contaminants in an alluvial aquifer. Linking to groundwater origin and residence time. Case study of the Vistrenque aquifer.

Sassine, Lara 01 December 2014 (has links)
Le but de ce travail est de tester une approche multi-traceurs permettant de caractériser l'origine (éléments majeurs, Sr, Br, 87Sr/86Sr, δ18O, δ2H) et les temps de résidence (3H/3He, CFC, SF6) des eaux, pour identifier l'origine et évaluer le devenir des contaminants dans une nappe alluviale superficielle et peu profonde, la nappe de la Vistrenque. Les molécules étudiées sont les triazines, le métolachlore, le diuron, la carbamazépine, le sulfaméthoxazole, le diclofénac et l'ibuprofène. L'aquifère étudié est alimenté par une recharge directe, occasionnant le lessivage des pesticides des sols, et une recharge latérale provenant de l'aquifère karstique adjacent entraînant une dilution des eaux de la nappe en triazines. Localement, une contribution des eaux de surface (cours d'eau locaux, eau importée du Rhône) à la recharge de la nappe est mise en évidence entraînant également une dilution des eaux de la nappe en triazines mais au contraire une contamination en COE, quoique, en faibles concentrations. Les âges apparents des eaux alluviales échantillonnées, déterminés principalement par le couple 3H/3He, varient entre 1.4 et 22 ans. Le couplage de l'âge des eaux à leurs teneurs en triazines montre une persistance de ces molécules dans le milieu souterrain, et une atténuation de leur signal d'entrée soulignant l'efficacité de leur interdiction en 2003. Finalement, les eaux de la nappe alluviale montrent des rapports de dégradation des triazines variant entre 0,3 pour les eaux influencées par les eaux de surface et 4,8 pour celles montrant des âges apparents de 22 ans, suggérant une augmentation de ce rapport avec le temps de transfert des pesticides dans le système. / The aim of this work is to test a multi-tracer approach allowing the characterization of groundwater origin and residence time in a shallow alluvial aquifer, the Vistrenque aquifer, in order to identify the origin and the fate of contaminants therein. The selected compounds for the study are triazines, metolachlor, diuron, carbamazepine, sulfamethoxazole, diclofenac, and ibuprofen. The studied aquifer is mainly fed by 1) a direct recharge inducing pesticides leaching from soil layers and unsaturated zone and 2) by a lateral recharge from the karst adjacent aquifer, which induces triazines dilution in the alluvial aquifer. A local contribution of surface water (local streams and imported Rhône River water) was evidenced in the alluvial groundwater inducing also triazines dilution but EOCs contamination nevertheless at low concentrations. The apparent age of the alluvial groundwater samples varies between 1.4 and 22 years. Linking groundwater age to triazines contents allowed to highlight, first, the persistence of these compounds in the alluvial groundwater and, second, the decreasing of their input signal in relatively recent groundwater samples in accordance with their forbidding in 2003. Finally, the Vistrenque alluvial groundwater showed triazines degradation ratios varying from 0.3 for groundwater influenced by surface water infiltration to 4.8 for groundwater characterized by relatively older apparent residence time on the order of 22 years. This suggests an increasing ratio with the transfer time of these compounds in the alluvial aquifer system.
57

Relações filogenéticas das espécies do gênero Rineloricaria Bleeker, 1862 (Siluriformes, Loricariidae, Loricariinae) / Phylogenetic relationships of the species of the Rineloricaria Bleeker, 1862 (Siluriformes, Loricariidae, Loricariinae)

Fichberg, Ilana 17 December 2008 (has links)
As espécies do gênero Rineloricaria são representantes típicos da subfamília Loricariinae, família Loricariidae, tradicionalmente caracterizada pela presença de odontódios recobrindo o corpo, corpo fortemente deprimido e ausência de nadadeira adiposa. Rineloricaria compreende 65 espécies nominais, sendo o gênero mais rico em espécies na subfamília Loricariinae. Estudos filogenéticos prévios sobre Loricariidae não concordaram sobre a hipótese de monofiletismo e posicionamento filogenético de Rineloricaria entre outros Loricariinae. Os objetivos deste trabalho foram testar o monofiletismo do gênero e determinar seu posicionamento entre outros Loricariinae. Um estudo filogenético incluindo 36 espécies de Rineloricaria e 181 caracteres foi realizado utilizando parcimônia estrita. Os principais dados para análise foram derivados de morfologia esquelética e morfologia externa. O grupo externo incluiu uma quantidade representativa de gêneros considerados proximamente relacionados à Rineloricaria, sendo Neoplecostomus microps o táxon mais externo e ponto de enraizamento. Os resultados indicaram que Rineloricaria é monofilético e grupo-irmão dos outros Loricariinae. Doze sinapomorfias sustentam o monofiletismo de Rineloricaria. Dentre estas, uma sinapomorfia exclusiva é um processo dorso-mesial bem desenvolvido no quarto osso faringobranquial. Outras sinapomorfias não exclusivas para o gênero são: uma grande placa pré-anal trapezoidal circundada por três placas poligonais e caracteres específicos de dimorfismo sexual. / The species of Rineloricaria are typical members of Loricariinae subfamily, family Loricariidae, traditionally characterized by the presence of odontodes covering the body, strongly depressed body and absence of adipose fin. Rineloricaria comprises 65 nominal species and it is the most speciesrich genus in the subfamily Loricariinae. Previous phylogenetic studies on Loricariidae have not agreed on the putative monophyly and phylogenetic position of Rineloricaria among other Loricariinae. The objectives of this work were to test the monophyly of the genus and to determine its position among other Loricariinae. A phylogenetic study including 36 species of Rineloricaria and 181 characters was conducted using strict parsimony. The primary data for the analysis came from skeleton and external morphology. The outgroup included a number of representatives of genera previously considered as closely related to Rineloricaria, with Neoplecostomus microps as the most distant outgroup and rooting point. The results indicate that Rinolericaria is monophyletic and sister group to all other Loricariinae. Twelve sinapomorphies support the monophyly of Rineloricaria. Unique among them is the presence of a well-developed dorso-mesial process on the fourth pharyngobranchial bone. Other non-unique synapomorphies for the genus include: a great trapezoidal preanal plate surrounded by three polygonal plates and some specific dimorphic sexual features.
58

Evolução temporal de parâmetros geoquímicos e mineralógicos em testemunhos sedimentares do estuário de Caravelas, Bahia, Brasil / Temporal evolution of geochemical e mineralogical proxies in sediment cores of the Caravelas estuary, Bahia, Brazil

Angeli, Jose Lourenço Friedmann 07 February 2018 (has links)
O Estuário de Caravelas, localizado na costa nordeste brasileira (extremo sul da Bahia) é considerado uma zona relativamente não impactada, com importante papel econômico e ecológico, devido a presença de fragmentos de Mata Atlântica, manguezais e sua localização próxima ao Complexo recifal de Abrolhos, o maior e mais importante do Oceano Atlântico Sul. No entanto, especialmente no último século, este estuário tem sido sujeito a impactos naturais e antrópicos que podem ter contribuído com mudanças neste sistema. Portanto, este estudo, baseado em uma abordagem \"multiproxy\", como análise de metais traço, elementos maiores, mineralogia, parâmetros descritivos da composição da matéria orgânica como COT, NT, razão Corg/Ntotal, &#948;13C, teve o objetivo de avaliar registro deposicional natural e antropogênico, do último século em 3 testemunhos datados por 210Pb e 137Cs. As taxas de sedimentação obtidas através do modelo CRS foram de 1,07 &#177; 0,13 cm ano-1 para o testemunho T2 (estuário médio), 0,65 &#177; 0,06 cm ano-1 para o testemunho T5 e 0,85 &#177; 0,09 cm ano-1 (desembocadura). O testemunho localizado no estuário médio (T2) apresentou uma maior influência terrígena com contribuição de plantas C3 para a matéria orgânica (- 26,50 < &#948;13C < -24,39; 21,38 < Corg/Ntotal < 37,67) e teores maiores do argilomineral caulinita, enquanto os testemunhos T5 e T8, localizados próximo a desembocadura do estuário, apresentaram uma maior influência marinha (- 26,48 < &#948;13C < -23,24; 4,18 < Corg/Ntotal < 21,34). Além disso, uma mudança significativa nos \"proxies\" orgânicos e inorgânicos, no início da década de 1960, mostrou a influência da abertura natural de um canal (Boca do Tomba) na hidrodinâmica e na distribuição dos sedimentos. A distribuição de elementos maiores e metais traço não apresentou um enriquecimento significativo e foi associada ao aporte litogênico, indicando o papel do Grupo Barreiras como uma importante fonte de material terrígeno para o estuário de Caravelas. / The Caravelas estuary, located on the Brazilian northeast coast (extreme South of Bahia) is considered a relatively unimpacted zone, with an important economic and ecological role, due to the presence of fragments of Atlantic Forest and mangroves, and its location next to the Abrolhos Bank, the largest and most important reefs of the south Atlantic Ocean. However, especially in the last century, this estuary has been subject to natural and anthropogenic impacts that may have contributed to changes in this system. Therefore, this study, based on a multiproxy approach, such as analysis of trace metals, major elements, mineralogy, parameters describing the composition of organic matter such as TOC, TN, Corg/Ntotal ratio, &#948;13C, had the main goal of evaluating the natural and anthropogenic depositional record, of the last century, in 3 sediment cores dated by 210Pb and 137Cs. The sedimentation rates obtained through CRS model were 1,07 &#177; 0,13 cm y-1 for sediment core T2 (middle estuary), 0,65 &#177; 0,06 cm y-1 for the T5 and 0,85 &#177; 0,09 cm y-1 for T8 (estuary mouth). The sediment core T2 showed a greater terrigenous influence with C3 plant contribution to the organic matter (- 26,50 < &#948;13C < -24,39; 21,38 < Corg/Ntotal < 37,67) and higher contents of kaolinite, meanwhile sediment cores T5 and T8, located at the mouth of the estuary, had a greater marine influence (- 26,48 < &#948;13C < -23,24; 4,18 < Corg/Ntotal < 21,34) and higher contents of calcite and aragonite. Furthermore, a significant change in the organic and inorganic proxies in the early 1960s showed the influence of the natural opening of an inlet (Boca do Tomba) on hydrodynamics and sediment deposition. Finally, the distribution of major and trace elements did not present a significant enrichment and was associated to lithogenic contribution, indicating the role of the Barreiras Group as an important source of terrigenous material to the Caravelas estuary.
59

Determinação da história deposicional recente do Alto Estuário Santista, com base nos teores de metais e na suscetiblidade magnética dos sedimentos / Determination of the recent depositional history of Santos and São Vicente Estuary, based on heavy-metal contents and magnetic susceptibility of the sediments

Fukumoto, Marina Midori 27 September 2007 (has links)
O Sistema Estuarino de Santos e São Vicente, localizado na porção central do litoral do Estado de São Paulo, abriga o mais importante complexo industrial costeiro do País, o Complexo Industrial de Cubatão, e o maior porto brasileiro, o Porto de Santos. Os objetivos deste trabalho foram o estudo do histórico da contaminação da área por metais pesados e a avaliação da aplicabilidade da suscetibilidade magnética na detecção de anomalias geoquímicas. Foram estudados três testemunhos próximos a fontes pontuais de poluição. A taxa de sedimentação foi determinada pelo método do 137Cs, a suscetibilidade magnética foi medida por um perfilador Bartington MS2C e o teor de metais foi analisado em ICP-OES. Os teores de Pb, Cu, Cr e Zn apresentaram uma tendência de aumento em direção ao topo dos testemunhos, mas os maiores teores não ocorrem na superfície, e sim a alguns centímetros de profundidade. A correlação entre os teores de Pb, Cu, Cr e Zn e a suscetibilidade magnética indicou a aplicabilidade desta na avaliação preliminar da qualidade dos sedimentos. O aporte desses metais pode ser associado a diversas fontes antrópicas relacionadas ao desenvolvimento urbano-industrial da região, como atividades industriais e portuárias e disposição irregular de resíduos sólidos e esgoto. / The Santos and São Vicente Estuary, located in the central portion of the coast of São Paulo state, has the most important industrial area of Brazilian coast, the Cubatão industrial complex, and the largest Brazilian harbour, the Santos harbour. The aims of this work were the study of the contamination history of the area by heavy metals and the applicability of magnetic susceptibility to detect geochemical anomalies. Three sediment cores were collected near polluted sites. The sedimentation rate was determined by 137Cs method, magnetic susceptibility was measured by a Bartington MS2C sensor and metal contents was analyzed by ICP-OES. Pb, Cu, Cr and Zn contents presented high values near the top of the cores. The highest values don?t occur in the surface, but in some centimeters of depth. The correlation between Pb, Cu, and Zn contents and magnetic susceptibility shows the applicability of magnetic susceptibility in the preliminary evaluation of sediment quality. The input of these metals can be associated to different anthropic sources, linked to urban and industrial development of the area: industrial and harbour activities and irregular waste and sewage disposal.
60

Evolução temporal de parâmetros geoquímicos e mineralógicos em testemunhos sedimentares do estuário de Caravelas, Bahia, Brasil / Temporal evolution of geochemical e mineralogical proxies in sediment cores of the Caravelas estuary, Bahia, Brazil

Jose Lourenço Friedmann Angeli 07 February 2018 (has links)
O Estuário de Caravelas, localizado na costa nordeste brasileira (extremo sul da Bahia) é considerado uma zona relativamente não impactada, com importante papel econômico e ecológico, devido a presença de fragmentos de Mata Atlântica, manguezais e sua localização próxima ao Complexo recifal de Abrolhos, o maior e mais importante do Oceano Atlântico Sul. No entanto, especialmente no último século, este estuário tem sido sujeito a impactos naturais e antrópicos que podem ter contribuído com mudanças neste sistema. Portanto, este estudo, baseado em uma abordagem \"multiproxy\", como análise de metais traço, elementos maiores, mineralogia, parâmetros descritivos da composição da matéria orgânica como COT, NT, razão Corg/Ntotal, &#948;13C, teve o objetivo de avaliar registro deposicional natural e antropogênico, do último século em 3 testemunhos datados por 210Pb e 137Cs. As taxas de sedimentação obtidas através do modelo CRS foram de 1,07 &#177; 0,13 cm ano-1 para o testemunho T2 (estuário médio), 0,65 &#177; 0,06 cm ano-1 para o testemunho T5 e 0,85 &#177; 0,09 cm ano-1 (desembocadura). O testemunho localizado no estuário médio (T2) apresentou uma maior influência terrígena com contribuição de plantas C3 para a matéria orgânica (- 26,50 < &#948;13C < -24,39; 21,38 < Corg/Ntotal < 37,67) e teores maiores do argilomineral caulinita, enquanto os testemunhos T5 e T8, localizados próximo a desembocadura do estuário, apresentaram uma maior influência marinha (- 26,48 < &#948;13C < -23,24; 4,18 < Corg/Ntotal < 21,34). Além disso, uma mudança significativa nos \"proxies\" orgânicos e inorgânicos, no início da década de 1960, mostrou a influência da abertura natural de um canal (Boca do Tomba) na hidrodinâmica e na distribuição dos sedimentos. A distribuição de elementos maiores e metais traço não apresentou um enriquecimento significativo e foi associada ao aporte litogênico, indicando o papel do Grupo Barreiras como uma importante fonte de material terrígeno para o estuário de Caravelas. / The Caravelas estuary, located on the Brazilian northeast coast (extreme South of Bahia) is considered a relatively unimpacted zone, with an important economic and ecological role, due to the presence of fragments of Atlantic Forest and mangroves, and its location next to the Abrolhos Bank, the largest and most important reefs of the south Atlantic Ocean. However, especially in the last century, this estuary has been subject to natural and anthropogenic impacts that may have contributed to changes in this system. Therefore, this study, based on a multiproxy approach, such as analysis of trace metals, major elements, mineralogy, parameters describing the composition of organic matter such as TOC, TN, Corg/Ntotal ratio, &#948;13C, had the main goal of evaluating the natural and anthropogenic depositional record, of the last century, in 3 sediment cores dated by 210Pb and 137Cs. The sedimentation rates obtained through CRS model were 1,07 &#177; 0,13 cm y-1 for sediment core T2 (middle estuary), 0,65 &#177; 0,06 cm y-1 for the T5 and 0,85 &#177; 0,09 cm y-1 for T8 (estuary mouth). The sediment core T2 showed a greater terrigenous influence with C3 plant contribution to the organic matter (- 26,50 < &#948;13C < -24,39; 21,38 < Corg/Ntotal < 37,67) and higher contents of kaolinite, meanwhile sediment cores T5 and T8, located at the mouth of the estuary, had a greater marine influence (- 26,48 < &#948;13C < -23,24; 4,18 < Corg/Ntotal < 21,34) and higher contents of calcite and aragonite. Furthermore, a significant change in the organic and inorganic proxies in the early 1960s showed the influence of the natural opening of an inlet (Boca do Tomba) on hydrodynamics and sediment deposition. Finally, the distribution of major and trace elements did not present a significant enrichment and was associated to lithogenic contribution, indicating the role of the Barreiras Group as an important source of terrigenous material to the Caravelas estuary.

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