Durante el presente trabajo de tesis se prepararon nanopartículas de cobre, oro y plata, soportadas en óxidos de diferente naturaleza. Estos soportes fueron tradicionales (SiO2 y γ-Al2O3), mesoporosos (MCM-41 y MCM-48) y óxidos reducibles (CeO2, α-Fe2O3). Los catalizadores fueron preparados por Impregnación Húmeda, por Deposición- Precipitación y a partir de nanopartículas generadas por reducción rápida de sales metálicas. Las muestras fueron caracterizadas principalmente por EXAFS, XANES, COFTIR, TEM, XRD y TPR. Los catalizadores se evaluaron en reacciones de interés para Química Fina: la hidrogenación selectiva de cinamaldehído o crotonaldehído y en la oxidación parcial del alcohol bencílico. Ambas se llevaron a cabo en fase líquida, en modo Batch, a fin de analizar el desempeño del catalizador en condiciones operacionales cercanas a las industriales. En el primer caso se empleó H2 como reductor y en el otro, aire como agente oxidante. El empleo del agua como solvente fue analizado para el caso de la oxidación parcial de alcohol. En todos los casos se analizó el reuso y la estabilidad de los catalizadores. Para las hidrogenaciones del cinamaldehído y crotonaldehído se determinó la actividad y la selectividad al alcohol insaturado (producto deseado) en condiciones de fase líquida (0,8 MPa, 100 °C). Se comprobó que el oro es intrínsecamente no selectivo, como contraste las nanopartículas de cobre presentan una selectividad intrínseca elevada. Dichas conclusiones se basaron en el análisis de los resultados catalíticos de partículas de cobre y oro sin soportar y de los correspondientes a catalizadores soportados sobre óxidos inertes, γ-Al2O3, SiO2, MCM-41 y MCM-48. Los resultados obtenidos sobre los diferentes catalizadores de cobre soportados muestran un incremento en la selectividad deseada, consecuencia de la transferencia de electrones desde el soporte (CeO2 y α-Fe2O3) hacia las nanopartículas de cobre o debido a la presencia de especies de Cu(I) generadas sobre los óxidos mesoporosos (de acuerdo a los resultados de caracterización por CO-FTIR y XRD). Para los catalizadores de cobre previamente calcinados, se concluyó sobre la existencia de transferencia de hidrógeno del solvente isopropanol. Para algunas formulaciones (Cu/γ-Al2O3 y Cu/SiO2) la selectividad se incrementó por dicho efecto. En forma general, los catalizadores de cobre presentaron una actividad (expresada como moles convertidos por unidad de masa y de tiempo) mucho menor que la correspondiente a los catalizadores basados en platino, tomados estos últimos como referencia. En cuanto a los valores de TOF del cobre también fueron menores que los de platino (en el rango de 1-3 x 10-3 s-1), salvo en el caso del soporte hematita que mostró un valor de aproximadamente 1x 10-2 s-1. Se estudió la hidrogenación del cinamaldehído en un medio supercrítico (scCO2 o scCO2 + Isoporopanol) empleando los catalizadores de cobre, con el objetivo de elevar la actividad de este metal. Efectivamente se observó un notorio incremento de la actividad, pero no se alcanzó la selectividad deseada. Al efectuar la comparación con los catalizadores de platino, medidos bajo condiciones supercríticas, no se alcanza la elevada selectividad del metal noble (90%) al emplear cobre. La oxidación parcial del alcohol bencílico fue estudiada a fin de determinar la actividad y la selectividad al benzaldehído (producto deseado) en condiciones de fase líquida (0,4 MPa, 120 °C) empleando agua como solvente. La selectividad deseada es del 100%, para catalizadores a base de cobre, aunque los valores de TOF fueron bajos entre 1 y 8 x 10-3 s-1 (en los catalizadores de Pt el TOF fue de aproximadamente de 2 x 10-2 s-1). Por el contrario los sistemas basados en metales nobles (AuH/MCM-48, AuNPs/MCM-41, Au/α-Fe2O3 y Au/CeO2 mostraron relativamente elevadas actividades (TOF entre 1 y 4 x 10-2 s-1) que resultan similares o mayores a las desarrolladas sobre catalizadores de Pt. En cuanto a la selectividad, para los catalizadores soportados sobre MCM y hematita la selectividad fue del 100%, mientras que para los catalizadores sobre ceria se observó una pérdida de selectividad a causa de la formación de ácido benzoico. Los catalizadores de plata no fueron extensamente estudiados, principalmente porque no se logró depositar cargas relativamente altas de este metal en las MCM. Los resultados indican que la plata, al igual que el oro, no es intrínsecamente selectiva para las reacciones de hidrogenación parcial. En cuanto a la oxidación el catalizador de plata, Ag/MCM-48 mostró una actividad intrínseca baja, menor a 0,1 x 10-6 moles/ g s, y si bien la selectividad al aldehído fue del 100%, los niveles de conversión fueron demasiado bajos para una aplicación práctica. / Copper, gold and silver nanoparticles supported on different oxide supports were prepared in the present work. The supports were traditional ones (SiO2 and γ- Al2O3), mesoporous systems (MCM-41 y MCM-48) and reducible oxides (CeO2, α- Fe2O3). The catalysts were prepared following the Wet Impregnation Method, Deposition – Precipitation and by the synthesis of naked nanoparticles by the fast reduction of metallic salts. The samples were characterized mainly by EXAFS, XANES, CO-FTIR, TEM, XRD and TPR. The catalysts were tested for reactions in the field of Fine Chemicals, i.e. the selective hydrogenation of cinnamaldehyde or crotonaldehyde and the partial oxidation of benzyl alcohol. Both reactions were carried out in liquid phase conditions in order to test the performance of the catalysts under experimental conditions similar to the ones corresponding to industrial processes. For the hydrogenation reaction, H2 was employed as the reductant, while for the oxidation, air was the oxidant. The employment of water as the solvent was evaluated for the oxidation reaction. For both all the cases the reuse of the spent catalysts and their stability were studied. For the hydrogenation of cinnamaldehyde and crotonaldehyde, the activity and the selectivity towards the unsaturated alcohol were measured in liquid phase (0,8 MPa, 100 °C). For the selective hydrogenation, it was concluded that gold is intrinsically unselective; on the other hand, copper nanoparticles show a high intrinsic selectivity. These conclusions were obtained from the analysis of the catalytic evaluation of unsupported gold and copper nanoparticles and of the corresponding catalysts supported on inert oxides, γ-Al2O3, SiO2, MCM-41 and MCM-48. The results obtained for the different copper catalysts show an increase in the desired selectivity, originated by an the electron transfer from the support (CeO2 or α-Fe2O3) to the copper nanopartilces o due to Cu(I) species present on the mesoporous oxide surface. For the copper catalysts previously calcined, a hydrogen transfer from the solvent isopropanol was detected. For some catalysts (Cu/γ-Al2O3 and Cu/SiO2) the selectivity was increased due to this effect. In a general way, the copper catalysts were less active than platinum ones, with TOF values of approximately 1 a 3 x 10-3 s-1, but for the case of the support hematite, which showed a TOF value of 1x 10-2 s -1. The hydrogenation of cinnamaldehyde was studied under supercritical solvents (scCO2 or scCO2 + Isoporopanol) employing copper catalysts, in order to increase the activitity. Certainly, a notable increase in the activity was measured; however the selectivities were relatively low. In supercritical conditions, is not achieved the high selectivity of the noble metal (90%) when using copper. The partial oxidation of benzyl alcohol was studied in order to determine the activity and the selectivity to benzal aldehyde (the desired product) under liquid phase conditions (0,4 MPa, 120 °C) employing water as the solvent. The desired selectivity was 100%, for copper based catalysts, though the TOF values were relatively low, in the 1-8 x 10-3 s-1 range (in the Pt catalysts the TOF was approximately 2 x 10-2 s-1). On the other hand, the catalysts based in noble metals (AuH/MCM-48, AuNPs/MCM-41, Au/α-Fe2O3 y Au/CeO2 and Pt catalyst) showed relatively high specific activities (TOF values in the 1-4 x 10 -2 s-1 range) and for the catalysts supported on MCM and hematite the selectivity was 100%, while for ceria catalysts showed a loss of selectivity because of the formation of benzoic acid. Silver catalysts were not extensively studied, mainly due to the fact than no high metal loading could be fixed to MCM-48. The preliminary results indicated that silver, as in the case of gold, is not intrinsically selective for the selective hydrogenation reactions. Regarding the partial oxidation, the Ag/MCM-48 sample showed a low activity and although the selectivity to the aldehyde was complete, the conversion levels were too low for a practical use.

O Río de La Plata (RdlP) e a costa leste do Uruguai representam uma zona de estudo de grande complexidade e interesse. Para caracterizar o transporte do sedimento terrígeno e assim decifrar o registro sedimentar, foram usados diferentes proxies: indicadores da origem da matéria orgânica (δ13C, δ15N e C/N), de contribuição terrestre (Al e Ti, Fe/Ca e Ti/Ca), de produtividade (conteúdo de Corg, Nt, CaCO3, Si, P, Ca, Ba, Al/Ti, Fe/Al, Ba/Al e Ba/Ti), e os indicadores de energia do ambiente (granulometria, diâmetro médio e seleção do sedimento), além das associações de proxies biológicos como tecamebas e ostrácodes, muito sensíveis ao padrão de salinidade, e foraminíferos bentônicos como integradores das principais características ambientais. Todos os proxies analisados refletiram o gradiente coincidente de influência continental versus marinha em direção a jusante na região do RdlP, provocada pela descarga dos rios Paraná e Uruguai, em contraposição à entrada de água marinha a montante. Na região oceânica, o gradiente observou-se na direção norte, provocado pelo efeito da vazão da pluma do RdlP e a vazão continental dos rios e lagoas dos Departamentos de Maldonado e Rocha. Este trabalho representa uma das primeiras abordagens multiproxies que revelam o registro nos sedimentos nessa área e garante boas perspectivas para estudos posteriores ambientais e paleoambientais. / The Rio de La Plata (RdlP) and the Uruguayan east shore represent a complex area. In order to characterize terrestrial sediment transport and to figure out the sedimentary record, different kind of proxies were used, both abiotic: bulk organic matter (δ13C, δ15N and C/N), terrestrial contribution (Al and Ti, Fe/Ca and Ti/Ca), productivity (Corg, Nt, CaCO3, Si, P, Ca, Ba, Al/Ti, Fe/Al, Ba/Al and Ba/Ti), environmental energy indicators (grain size), and biological proxies: tecamoebians and ostracoda, which are extremely susceptive to salinity changes, and benthic foraminifera as a environmental characteristics integrator. All analysed proxies reflected the difference between terrestrial versus marine gradient downstream on the RdlP, caused by the Paraná and Uruguay rivers discharge, versus marine water inlet upstream. In the oceanic region, the gradient was northward, caused by RdlP plume and terrestrial discharge from Maldonado and Rocha Department rivers and lagoons. This dissertation represents one of the first multiproxy approach, which reveals the sediment record in this area and, which guarantees the good perspectives for subsequent environmental and paleoenvironmental studies.

En 1853, des constitutions fédérales et républicaines sont votées, non sans conflits, dans la région du Rio de la Plata et en Nouvelle-Grenade. Dans les deux constitutions, l'exclusion de la femme comme sujet de droits politiques est explicite. De façon singulière, cette même année, l'Assemblée législative de Vélez, une province de la Nouvelle-Grenade, promulgue le droit de vote aux élections sans distinction de sexe, événement qui, s'il ne pourra prospérer à cause d'un véto présidentiel, représente le premier fait de reconnaissance politique de la femme sur le continent hispano américain. Malgré cet antécédent, la Colombie est une des les derniers des états d'Amérique Latine à avoir accordé le suffrage aux femmes (1954), alors qu'en Argentine il y eut plusieurs tentatives infructueuses avant la loi nationale de 1947. La décision de l'assemblée de Vélez peut être considérée comme un indice clair de la transition de la femme "objet d'écriture" à la femme "sujet de l'action". Mais ce n'est pas le seul: dans cette thèse, nous soutiendrons que des traces de cette transition apparaissent dans les écrits de ces hommes du dix-neuvième siècle qui étaient considérés comme les forgeurs de la Nation. Concrètement, nous ne rentrerons pas dans l'étude de la femme en tant que sujet, mais notre regard se portera sur la façon dont elle est construite comme «objet », en analysant ses caractéristiques et les interstices qui montrent cette transition. Contrairement à ce qu'on pourrait attendre d'une vision mécanique des causes et des effets, la femme n'a pas toujours été écrite "négativement" mais elle a été incluse dans un champ de forces dans lequel les significations se disputaient entre elles. Celle thèse cherche à meure en lumière les figures diverses et parfois contradictoires de la femme qui apparaissent dans les textes écrits par des hommes du dix-neuvième siècle préoccupés par la fondation de la Nation. / In 1853, in the Rio de la Plata as well as in Nueva Granada, promulgated federal and republican constitutions are dictated not without tensions. In both there is an explicit exclusion of women as subjects of political rights. Interestingly, that year the Legislature Assembly of Velez, province of Nueva Granada, promulgated electoral voting rights regardless of sex, an event that in spite of not prospering because of the presidential veto, represents the first political recognition of women in our continent. Despite this background, Colombia is the latest Latin American state which granted women's suffrage (1954) while in Argentina there were several failed attempts until the national law of 1947. The decision of the Assembly of Velez can be considered a clear indication of the transition of women from 'object of writing' to 'subject of the action'. But it is not the only one : in this thesis we will argue that in the writings of nineteenth-century men, who were considered forgers of the nation, there appear traces of that transition. Specifically, the look will be on how the woman is built as an "object", observing the characteristics and also the gaps that show this transition. Contrary to what is expected from a mechanical view of cause and effect, the woman was not always written 'negatively' but was included in a force field in which the senses vie with each other. This thesis seeks to uncover the different and sometimes contradictory figurations of the women that appear in texts written by me of the nineteenth century concerned about the founding of the nation.

O Río de La Plata (RdlP) e a costa leste do Uruguai representam uma zona de estudo de grande complexidade e interesse. Para caracterizar o transporte do sedimento terrígeno e assim decifrar o registro sedimentar, foram usados diferentes proxies: indicadores da origem da matéria orgânica (δ13C, δ15N e C/N), de contribuição terrestre (Al e Ti, Fe/Ca e Ti/Ca), de produtividade (conteúdo de Corg, Nt, CaCO3, Si, P, Ca, Ba, Al/Ti, Fe/Al, Ba/Al e Ba/Ti), e os indicadores de energia do ambiente (granulometria, diâmetro médio e seleção do sedimento), além das associações de proxies biológicos como tecamebas e ostrácodes, muito sensíveis ao padrão de salinidade, e foraminíferos bentônicos como integradores das principais características ambientais. Todos os proxies analisados refletiram o gradiente coincidente de influência continental versus marinha em direção a jusante na região do RdlP, provocada pela descarga dos rios Paraná e Uruguai, em contraposição à entrada de água marinha a montante. Na região oceânica, o gradiente observou-se na direção norte, provocado pelo efeito da vazão da pluma do RdlP e a vazão continental dos rios e lagoas dos Departamentos de Maldonado e Rocha. Este trabalho representa uma das primeiras abordagens multiproxies que revelam o registro nos sedimentos nessa área e garante boas perspectivas para estudos posteriores ambientais e paleoambientais. / The Rio de La Plata (RdlP) and the Uruguayan east shore represent a complex area. In order to characterize terrestrial sediment transport and to figure out the sedimentary record, different kind of proxies were used, both abiotic: bulk organic matter (δ13C, δ15N and C/N), terrestrial contribution (Al and Ti, Fe/Ca and Ti/Ca), productivity (Corg, Nt, CaCO3, Si, P, Ca, Ba, Al/Ti, Fe/Al, Ba/Al and Ba/Ti), environmental energy indicators (grain size), and biological proxies: tecamoebians and ostracoda, which are extremely susceptive to salinity changes, and benthic foraminifera as a environmental characteristics integrator. All analysed proxies reflected the difference between terrestrial versus marine gradient downstream on the RdlP, caused by the Paraná and Uruguay rivers discharge, versus marine water inlet upstream. In the oceanic region, the gradient was northward, caused by RdlP plume and terrestrial discharge from Maldonado and Rocha Department rivers and lagoons. This dissertation represents one of the first multiproxy approach, which reveals the sediment record in this area and, which guarantees the good perspectives for subsequent environmental and paleoenvironmental studies.

Utilizing both primary and secondary literature, this study attempts to illustrate that the origins of one of Latin America’s most significant wars, the Paraguayan War (1864-70), are understandable only when viewed within the context of the historical development of the Rio de la Plata as a region. Adopting the framework provided by Robert N. Burr in his pioneering work on the South American continental balance of power system. “By Reason or Force: Chile and the Balancing of Power in South America, 1830-1905” (Berkely, 1965), this thesis examines one particular outgrowth of the historical process in the Rio de Plata: The development of a regional balance of power in the area. It also illustrates that such systems of international power politics are not necessarily promotive of stability and equanimity in the relations between nations: that balance of power systems are not static but constantly changing, and that such changes are conducive to friction, intrigue, and war.

Mid- and Late Holocene paleoceanographic changes over the S/SE Brazilian continental shelf have been accessed through a multi-proxy approach. Sedimetological, geochemical and microfaunal proxies were investigated in three high resolution marine sedimentary cores collected along the S/SE Brazilian shelf and discussed under a regional and global oceanographic and climatic perspective. The depositional processes of the S/SE Brazilian margin were submitted to two different hydrodynamic controls during Mid- and Late Holocene: (i) the northward penetration of the La Plata River Plume, bringing La Plata River derived sediments, and (ii) the high energetic Brazil Current onshore/offshore movements transporting SE Brazilian derived sediments for the northernmost part of the Santos Basin (25°S) during the Mid-Holocene. In the Late Holocene, especially after 3000 yr cal. BP, La Plata River derived sediments reached up to 25°S, highlighting a stronger influence of the La Plata River over the S/SE Brazilian shelf as a result of increase in precipitation over the La Plata River drainage basin. As the La Plata River colder and less saline waters influence over the S/SE Brazilian shelf increased, the oligotrophic waters of the shelf were fertilized, promoting enhancement of surface waters primary productivity and seafloor exportation. In the vicinity of 25°S, surface waters primary productivity was also enhanced by increase in colder and less saline South Atlantic Central Waters (SACW) shelf penetration. An overall a background trend of lower water temperature and salinities corroborates to a stronger influence of the La Plata River Plume waters during the Late Holocene as a result of higher precipitation over SE South America. This trend followed the summer insolation at 30°S, in accordance to other proxy records and numerical models. In the northernmost part of study area, superimposed to the general background trend, two major temperature and salinity negative incursions with abrupt contacts centered at 5500 yr cal. BP and after 2800 yr cal. BP highlight multi-centennial scale changes, possibly related to SACW shelf penetrations due to persistent NE winds. These changes occurred simultaneously to rapid climatic events at regional and global spatial scale. AMOC slowdown events, mediated by amplifying mechanisms, are the proposed triggering mechanism for the changes observed in the SE Brazilian shelf records. The amplifying mechanisms may have changed throughout time and as atmospheric teleconnections are not yet fully understood we hypothesize that different modes of climatic variability, such as ENSO and the South Atlantic dipole, may have acted as mediators during Mid- and Late Holocene. / Neste estudo uma visão multi-proxy foi aplicada na compreensão das mudanças nas condições oceanográficas em que a plataforma continental S/SE Brasileira foi submetida ao longo do Holoceno Médio e Tardio. Para isso proxies sedimentológicos, geoquímicos e microfaunísticos foram estudados em três testemunhos marinhos de alta resolução coletados ao longo da plataforma S/SE do Brasil e discutidos sob uma perspectiva oceanográfica e climática regional e global. No Holoceno Médio e Tardio, os processos deposicionais da plataforma S/SE Brasileira foram influenciados por dois processos hidrodinâmicos distintos: (i) a presença da Pluma do Rio La Plata, trazendo sedimentos oriundos da Bacia de drenagem do Rio La Plata, e (ii) os movimentos onshore/offshore da Corrente do Brasil, no Holoceno Médio, trazendo sedimentos oriundos da margem SE Brasileira para porção norte da Bacia de Santos (25°S). A zona de influência do Rio La Plata estendeu-se a latitudes mais ao norte atingindo 25°S, no Holoceno Tardio, especialmente nos últimos 3000 anos, como resultado do aumento nos regimes de precipitação sobre a Bacia de drenagem desse rio. As águas superficiais da plataforma S/SE Brasileira foram fertilizadas pelas águas mais frias e menos salinas da Pluma do Rio La Plata, disponibilizando mais matéria orgânica para o sistema bentônico. Nas proximidades de 25°S, a penetração na plataforma da Água Central do Atlântico Sul (ACAS) também promoveu aumento na produtividade primária das águas superficiais. Ao longo do Holoceno Médio e Tardio, uma tendência geral de diminuição da temperatura e salinidade das águas superficiais corrobora com uma maior influência da Pluma do Rio La Plata sobre a plataforma S/SE Brasileira como consequência de um aumento na precipitação no SE da América do Sul. Essa tendência segue a tendência da insolação de verão em 30°S, e concorda com outros registros proxy e modelos numéricos. Na porção norte da área de estudo, sobreposta à tendência geral, duas grandes incursões negativas temperatura e salinidade, com contatos abruptos, centradas em 5500 anos cal. BP e depois de 2800 anos cal. BP sugerem a ocorrência de mudanças de escala multi-centenárias, possivelmente relacionadas a penetração da ACAS na plataforma em decorrência de ventos de NE persistentes. Estas mudanças ocorreram simultaneamente a eventos rápidos climáticos em escala regional e global. Eventos de desaceleração da AMOC, mediada por mecanismos de amplificação, são propostos como o mecanismo responsável por desencadear estas mudanças (triggering mechanism). Os mecanismos amplificadores podem ter mudado ao longo do tempo e dado o não total entendimento das teleconexões atmosféricas do sistema climático, colocamos como hipótese que, no Holoceno Médio e Tardio, diferentes modos de variabilidade climática tais como, ENSO e dipolo do Atlântico Sul, podem ter atuado.

Mid- and Late Holocene paleoceanographic changes over the S/SE Brazilian continental shelf have been accessed through a multi-proxy approach. Sedimetological, geochemical and microfaunal proxies were investigated in three high resolution marine sedimentary cores collected along the S/SE Brazilian shelf and discussed under a regional and global oceanographic and climatic perspective. The depositional processes of the S/SE Brazilian margin were submitted to two different hydrodynamic controls during Mid- and Late Holocene: (i) the northward penetration of the La Plata River Plume, bringing La Plata River derived sediments, and (ii) the high energetic Brazil Current onshore/offshore movements transporting SE Brazilian derived sediments for the northernmost part of the Santos Basin (25°S) during the Mid-Holocene. In the Late Holocene, especially after 3000 yr cal. BP, La Plata River derived sediments reached up to 25°S, highlighting a stronger influence of the La Plata River over the S/SE Brazilian shelf as a result of increase in precipitation over the La Plata River drainage basin. As the La Plata River colder and less saline waters influence over the S/SE Brazilian shelf increased, the oligotrophic waters of the shelf were fertilized, promoting enhancement of surface waters primary productivity and seafloor exportation. In the vicinity of 25°S, surface waters primary productivity was also enhanced by increase in colder and less saline South Atlantic Central Waters (SACW) shelf penetration. An overall a background trend of lower water temperature and salinities corroborates to a stronger influence of the La Plata River Plume waters during the Late Holocene as a result of higher precipitation over SE South America. This trend followed the summer insolation at 30°S, in accordance to other proxy records and numerical models. In the northernmost part of study area, superimposed to the general background trend, two major temperature and salinity negative incursions with abrupt contacts centered at 5500 yr cal. BP and after 2800 yr cal. BP highlight multi-centennial scale changes, possibly related to SACW shelf penetrations due to persistent NE winds. These changes occurred simultaneously to rapid climatic events at regional and global spatial scale. AMOC slowdown events, mediated by amplifying mechanisms, are the proposed triggering mechanism for the changes observed in the SE Brazilian shelf records. The amplifying mechanisms may have changed throughout time and as atmospheric teleconnections are not yet fully understood we hypothesize that different modes of climatic variability, such as ENSO and the South Atlantic dipole, may have acted as mediators during Mid- and Late Holocene. / Neste estudo uma visão multi-proxy foi aplicada na compreensão das mudanças nas condições oceanográficas em que a plataforma continental S/SE Brasileira foi submetida ao longo do Holoceno Médio e Tardio. Para isso proxies sedimentológicos, geoquímicos e microfaunísticos foram estudados em três testemunhos marinhos de alta resolução coletados ao longo da plataforma S/SE do Brasil e discutidos sob uma perspectiva oceanográfica e climática regional e global. No Holoceno Médio e Tardio, os processos deposicionais da plataforma S/SE Brasileira foram influenciados por dois processos hidrodinâmicos distintos: (i) a presença da Pluma do Rio La Plata, trazendo sedimentos oriundos da Bacia de drenagem do Rio La Plata, e (ii) os movimentos onshore/offshore da Corrente do Brasil, no Holoceno Médio, trazendo sedimentos oriundos da margem SE Brasileira para porção norte da Bacia de Santos (25°S). A zona de influência do Rio La Plata estendeu-se a latitudes mais ao norte atingindo 25°S, no Holoceno Tardio, especialmente nos últimos 3000 anos, como resultado do aumento nos regimes de precipitação sobre a Bacia de drenagem desse rio. As águas superficiais da plataforma S/SE Brasileira foram fertilizadas pelas águas mais frias e menos salinas da Pluma do Rio La Plata, disponibilizando mais matéria orgânica para o sistema bentônico. Nas proximidades de 25°S, a penetração na plataforma da Água Central do Atlântico Sul (ACAS) também promoveu aumento na produtividade primária das águas superficiais. Ao longo do Holoceno Médio e Tardio, uma tendência geral de diminuição da temperatura e salinidade das águas superficiais corrobora com uma maior influência da Pluma do Rio La Plata sobre a plataforma S/SE Brasileira como consequência de um aumento na precipitação no SE da América do Sul. Essa tendência segue a tendência da insolação de verão em 30°S, e concorda com outros registros proxy e modelos numéricos. Na porção norte da área de estudo, sobreposta à tendência geral, duas grandes incursões negativas temperatura e salinidade, com contatos abruptos, centradas em 5500 anos cal. BP e depois de 2800 anos cal. BP sugerem a ocorrência de mudanças de escala multi-centenárias, possivelmente relacionadas a penetração da ACAS na plataforma em decorrência de ventos de NE persistentes. Estas mudanças ocorreram simultaneamente a eventos rápidos climáticos em escala regional e global. Eventos de desaceleração da AMOC, mediada por mecanismos de amplificação, são propostos como o mecanismo responsável por desencadear estas mudanças (triggering mechanism). Os mecanismos amplificadores podem ter mudado ao longo do tempo e dado o não total entendimento das teleconexões atmosféricas do sistema climático, colocamos como hipótese que, no Holoceno Médio e Tardio, diferentes modos de variabilidade climática tais como, ENSO e dipolo do Atlântico Sul, podem ter atuado.

La recherche se focalise sur l’étude d’un corpus composé d’œuvres littéraires françaises et de la région du Río de la Plata (Amérique du Sud), qui vont de la seconde moitié du XIXe siècle jusqu’à 2015. L’étude s’appuie aussi sur l’analyse d’images iconographiques, pour analyser l’image du personnage de l’employée domestique qui se dégage dans la convergence entre la littérature et les arts plastiques. Dans une perspective comparatiste, le travail explore les formes de la représentation de cette figure d’un point de vue stylistique, thématique et politique. Les contiguïtés entre les deux corpus nationaux montrent non seulement l’existence d’une dynamique d’échanges entre le Río de la Plata et la France en ce qui concerne les débats esthétiques et politiques, mais aussi l’existence d’un partage du sensible commun. L’étude établit une périodisation des modes de représentation du personnage, depuis son accès au rôle principal, à travers l’analyse de la construction littéraire de sa voix, de son parcours de vie, de son intimité et du regard qu’il porte sur le monde. Cette recherche se fonde sur la conviction que la domesticité est un fait social total, dont l’analyse mène à une radicale interrogation ontologique. Cela marque de son empreinte le personnage et les rapports qui se tissent autour de lui et résulte dans sa puissance politique, dont les auteurs se sont emparés. Finalement, et suivant une tradition d’études qui se font sur la longue durée et en prenant compte d’une certaine « transnationalisation » de la figure, nous entendons encourager l’étude de la domestique dans le domaine de la littérature comparée. / This research focuses on the study of a corpus composed of French literary works, as well as those from the Latin American region of Río de la Plata, ranging from the mid-nineteenth century to the year 2015. The study is also based on the analysis of some iconographic images, in order to analyse the image of the housemaid’s character that emerges in the convergence between literature and visual arts. From a comparative perspective, the work explores the forms which represent this figure from a stylistic, thematic and political point of view. Adjacencies between the two national corpora show not only the existence of exchanges between the Río de la Plata and France regarding the aesthetic and political debate, but also the existence of a common distribution of the sensible. The study establishes a periodization of the character representation modes, from the character’s access to the main role, through to the analysis of the literary construction of her voice, her course of life, her intimacy and the view she has of the world. This research is based on the belief that domestic service is a total social fact, whose analysis leads to “a radical ontological questioning”. This leaves a mark on the character and on the plot that develops around her. As a result, the authors capture an image of political power. Following on from a tradition of studies that are made in the long term and also taking into account a certain "trans-nationalisation" of the character, we intend to promote the study of housemaids and domestic service in the field of comparative literature.

Zugleich: Diss. / Literaturverz.

Cette recherche est une approche sur les processus transfrontaliers dans la Triple FrontièreBrésil-Argentine-Paraguay. Initialement nous avons cherché à identifier les acteurs et les nouveaux usages du territoire, ainsi que le rôle des régions transfrontalières au sein des blocs commerciaux régionaux en Amérique du Sud et en Europe. Afin de utiliser l'expérience européenne dans les politiques pour les régions frontalières, on a analysés les initiatives d'intégration dans l’Union européenne et un travail de terrain dans la Grande Région a été réalisé, dont les résultats ont été utilisés pour la composition d'un chapitre de la recherche. Au cours du present étude l'importance de l'infrastructure routière, l'énergie et les télécommunications, le rôle du tourisme, les diverses initiatives de coopération et d'interaction dans le Triple Frontière, ainsi que les effets négatifs desprocessus transfrontaliersont été également analysé. Dans la recherche, les acteurs et les processus transfrontaliers ont été signalées par des coremas et des cartes. Les éléments énumérés ont servi à soutenir l'idée que actuellement une régiontransfrontalière se dessine au coeur du bassin de La Plata. / A presente pesquisa constitui uma abordagem acerca dos processos de transfronteirização na Tríplice Fronteira Brasil-Argentina-Paraguai. Inicialmente buscou-se identificar os atores e os novos usos do território, bem como o papel das regiões transfronteiriças dentro dos blocos regionais de comércio na América do Sul e na Europa. Com o intuito de aproveitar a experiência europeia no âmbito das políticas para regiões transfronteiriças, foram analisadas as iniciativas de integração e foi realizado um trabalho de campo na Grande Région, cujos resultados serviram para a composição de um capítulo da pesquisa. No decorrer da pesquisa também foram analisados a importância das infraestruturas viárias, energéticas e de telecomunicações, o papel do turismo, as diferentes iniciativas de cooperação e interação na Tríplice Fronteira, bem como os efeitos negativos da transfronteirização. Os atores e os processos de transfronteirização foram relatados através de coremas e mapas elaborados para a pesquisa. Os elementos elencados serviram para embasar a ideia de que está surgindo uma região transfronteiriça no coração da Bacia do Prata. / This research is an approach to cross-border processes in the Tri-Border Area, between Brazil, Argentina and Paraguay. Initially we sought to identify the actors, the new land uses and the role of cross-border regions within regional trading blocs in South America and Europe. To take advantage of the European experience in policies for border regions, we analyzed the integration initiatives in the European Union and a fieldwork in the Grande Région was conducted. The results of the fieldwork were used to compose a chapter of the research. In the present study the importance of road infrastructure, energy and telecommunications, the role of tourism, initiatives of cooperation and interaction in Tri-Border Area, as well as the negative effects of cross-border processes were also analyzed. In the present research, actors and border processes have been reported by graphic schemes and maps. The items listed were used to support the idea that, presently, a cross-border region is emerging in the heart of La Plata Basin.