O pluton Desemborque, de idade neoproterozóica, é parte do denominado Maciço Guaraú, aflorante na região sul do de estado de São Paulo e está inserido no contexto geológico da Província Graciosa. É composto por biotita sienogranito a álcali feldspato granito, metaluminosos a moderadamente peraluminosos, que apresentam assinaturas geoquímicas típicas de granitos de tipo-A, como conteúdos relativamente altos de álcalis, além de concentrações significativas de elementos LIL e HFS. Apresentam alteração hidrotermal em graus variáveis, claramente evidenciados tanto pelas texturas quanto pelas composições registradas em seus minerais essências e acessórios, destacando-se a albitização e a greisenização. Os feldspatos alcalinos são pertitas ou mesopertitas zonadas. Algumas composições químicas integradas exibem valores entre \'Or IND 53-58\'\'Ab4 IND 42-46\' (núcleos) e \'Or IND 68-71\'\'Ab4 IND 29-32\' (bordas). A maior parte das composições obtidas dos plagioclásios correspondem a albita, com poucos cristais classificados como oligoclásio sódico. Albita pura e pós magmática ocorre intersticialmente aos feldpastos ou como microvenulações. São encontradas duas fases micáceas estritamente magmáticas: biotitas castanhas (annita) e esverdeadas (protolitionita-siderofilita). Associadas ao processo de greisenização que substitui biotitas e feldspatos encontram-se micas verdes claras a incolores anteriormente definidas como zinnwaldita, que aqui são reclassificadas como fengita. Minerais acessórios foram examinados e estudados com imageamento BSE e análises quantitativas por EDS. Os mais comuns são: zircão, allanita, torita, cassiterita, galena, hematita, ilmenita, monazita, , columbita e fluoretos de terras raras. Entre eles, os primários (e.g zircão, allanita e cassiterita) exibem microestruturas ou transformações químicas relacionadas à processos tardios de alteração hidrotermal, enquanto outros foram desenvolvidos durante este processo, como torita, xenotímia e fluoretos de elementos terras raras e de ítrio. Os granitos típicos do Desemborque são bastante evoluídos e relativamente homogêneos com um estreito intervalo composicional, como \'SiO IND 2\' (76-77% em peso), álcalis (\'Na IND 2\'O até 4,1 % e \'K IND 2 O\' até 4,5 %), \'Al IND 2\'\'O IND 3\' (ca. 12%) e \'Fe IND 2\'\'O IND 3\' (~1%). Outros óxidos comuns contribuem com concentrações bem baixas como CaO e MgO. As rochas hidrotermais exibem relativo enriquecimento em\' Fe IND 2\'\'O IND 3\' (5,27 % em peso para o greisen) além de F, Rb, Sn e Li e empobrecimento em \'Na IND 2\'O (0,26%). As temperaturas de saturação em Zr fornecem valores entre 750-860º C, e que pode ser extrapolada como uma aproximação para a temperatura do líquido do sistema magmático. Dados geológicos, petrográficos e normativos indicam colocação em níveis rasos, com pressões não muito maiores que 1 kbar. Suas características remetem a cristalização em fugacidades de oxigênio relativamente baixas, uma exceção entre a associação aluminosa da Província Graciosa. As determinações de idades isotópicas U/Pb são problemáticas devido aos aspectos texturais dos cristais de zircão e componentes herdados. Após o tratamento dos dados chegou-se a uma idade estatisticamente mais confiável (590 ± 12 Ma) e em parte, coerente com a literatura. / The Neoproterozoic Desemborque Pluton is a part of the so-called Guaraú Granitic Massif, which crops out in the southern region of the state of São Paulo and is inserted in the geological context of Graciosa Province. It is made of metaluminous to moderately peraluminous biotite sienogranites and alkali-feldspar granites which present geochemichal signatures most typical of A-type granites, as for the relatively high total alkali, LILE and HFSE contents. It shows hydrothermal alteration imprinted to a variable grade, as clearly evidenced by textural as well as compositional features registered in its essential and accessory minerals, standing out albitization and greisenization. Alkali-fedspars are zoned perthite or meso-phertite. Some integrated chemical compositions gave values between \'Or IND 53-58\'\'Ab IND 42-46\' (crystal cores) and \'Or IND 68-71\'\'Ab4 IND 29-32\' (crystal rims). Most of the obtained plagioclase compositions correspond to albite, a minor number being classified as sodic oligoclase. Post-magmatic, almost pure albite, occurs intersticialy to feldspars or as minor veinlets. Two main types of magmatic micas were recognized: red-brown annitic biotite and a green protolitionite-siderofilite. Light green to colorless micas associated with the greisenization process that replaces biotite and feldspars previously called a zinwaldite-like mica were reclassified to fengite type. Accessory minerals were examined and studied with BSE imaging and EDS qualitative analysis. The most common are zircon, allanite, thorite, cassiterite, galena, hematite, ilmenite, monazite, xenotime, columbite, fluorite and REE fluorides. Among them, the primary ones (e.g., zircon, allanite, cassiterite) show micro-structural or chemical transformations related to the hydrothermal alteration, while others were developed during such process, as for thorite, xenotime, and the REE and Y fluorides. The main Desemborque granites are highly evolved and relatively homogenous, with a narrow chemical compositional range as for \'SiO IND 2\' (76-77% wt %), alkalis (\'Na IND 2O\' up to 4.1 % e \'K IND 2O\' up to 4.5 %), \'Al IND 2\'\'O IND 3\' (ca. 12%) e \'Fe IND 2\'\'O IND 3\' (~1%). Other common oxides contribute with very low concentrations like CaO and MgO. Hydrothermal rocks show relatively \'Fe IND 2\'\'O IND 3\'enrichment (up to 5.2 wt.% in the greisen sample) in addition F, Rb, Sn e Li and depletion in \'Na IND 2 O\' (down to 0.26 wt.%) Zircon saturation temperature gives values in the 750-800º C range, which approaches well the liquidus of such magmatic system. Geological, petrographic, and normative data indicate relative shallow emplacement levels, at pressures no greater than ca. 1 Kbar, and crystallization under a relatively low \'f IND O2\' , a exception in the aluminous association of the Graciosa Province. U/Pb isotopic age determinations are problematic due textural aspects of zircon cristals and inherited components. After the treatment of the data was reached a statistically more confiable age (590 ± 12 My) and, in part, coherent with the literature.

A remineralização é uma prática antiga que está associada a aplicação de pós de rocha no solo visando a melhoria das propriedades edáficas e por fim o aumento da produtividade, associado também a redução dos custos de produção, uma vez que os remineralizadores possuem menor preço comparado com fertilizantes sintéticos solúveis. Porém ainda existem divergências nos resultados obtidos com o uso de remineralizadores, por vezes associados a dificuldade na descrição e controle dos fatores que podem interferir no processo, como clima, características do solo e do remineralizador empregado. Esta tese tem por objetivo investigar a dissolução de um remineralizador em experimentos em diferentes níveis de complexidade e avaliar as alterações mineralógicas correspondentes, inclusive com ênfase na possibilidade de neoformação de minerais. No experimento in vitro foi possível identificar os efeitos do tamanho das partículas e dos diferentes solventes na dissolução dos minerais do remineralizador. Aumentando o nível de complexidade, no experimento em colunas contendo solo, foi possível identificar principalmente um incremento nos teores de Ca+2, Mg+2, K+ trocáveis no solo, além do Na+, Fe e Si no tratamento com a aplicação do remineralizador. Também houve aumento dos teores de Fe e Al extraídos em solução de ditionito-citrato-bicarbonato e oxalato de amônio e, em concordância com os diagramas de estabilidade termodinâmica dos minerais, foi constatada a precipitação de óxidos de baixa cristalinidade no tratamento com remineralizador. No experimento em vasos, a presença das plantas atuou como um dreno, mas mesmo assim com aumento principalmente dos teores de Ca+2 e Mg+2 trocáveis, mas sem ser constatada a precipitação de óxidos amorfos. Por fim, o experimento de campo reafirma o que foi observado nos dois experimentos anteriores, no qual houve aumento dos teores de Ca+2, Mg+2, Na+ e Si trocáveis. Em todos os níveis de experimentos, de forma geral, foi possível observar a maior contribuição de plagioclásios cálcio-sódicos e clinopiroxênios no fornecimento de Ca+2 e Mg+2, principalmente, além de Na+, ferro e silício. / The remineralization is an ancient practice of application of rock powders into the soil in order to improve the soil properties and increase productivity. It is also associated with the reduction of production costs, since remineralizers are cheaper as compared to soluble synthetic fertilizers. Contradiction among the results obtained from the use of remineralizadores frequently be associated with difficulty to describe and control of the factors that may affect the results, such as climate, soil characteristics and characterization of the remineralizers used. This thesis aims to investigate the dissolution of remineralizers in experiments with increasing levels of complexity and evaluate the mineralogical changes, emphasing the possibility of neoformation minerals. In the in vitro experiment, it was possible to identify the effects of particle size and different solvents in the dissolution of the mineral presents in the remineralizer. The rock powder when applied in columns containing soil allowed to identify an increase in Ca+2, Mg+2, K+ exchangeable, including Na+, Fe and Si. Also increased the levels of Fe and Al extracted solution of sodium dithionite-citrate-bicarbonate, ammonium oxalate and in accordance with the thermodynamic stability diagrams of minerals, the precipitation of low crystallinity oxide in remineralizer treatment. In the pot experiment, the presence of plants acted as a drain, but there was still an increase of Ca+2 and Mg+2 exchangeable, specially, but without was observed precipitation of amorphous oxides. Finally, field experiment confirms what was observed in the two previous experiments in which there was an increase in Ca+ 2, Mg+ 2, Na+ and Si exchangeable. At all experiments, in general, we observed the greatest contribution of plagioclase and clinopyroxenes in providing of Ca+2 and Mg+2 in large amount, as well as Na+, Fe and Si in minor quantity.

O saprolito é um corpo geológico constituído pela mistura de minerais primários e secundários resultantes do intemperismo físico e químico, o qual mantém vestígios da estrutura original da rocha. Difere do solo pela evidente filiação litogenética e insignificante atividade biológica. Apesar das definições, no entanto, o limite e a distinção entre solo e saprolito nem sempre são claros, devido a continuidade entre estes corpos em termos de processos hidrológicos e geoquímicos, bem como de suas composições físicas e mineralógicas, o que gera grande confusão nas descrições morfológicas e na organização de informações. Devido ao caráter multidisciplinar das ciências envolvidas no estudo do saprolito e a dedicação parcial de todas elas, há uma grande carência de padronização de termos e procedimentos para sua caracterização e análise. O objetivo geral desta tese é a caracterização de saprolitos desenvolvidos a partir de variadas litologias, no intuito da elaboração de procedimentos para a descrição, classificação e análise de saprolitos. Especificamente objetivou-se avaliar detalhadamente os padrões de alteração física, mineralógica e geoquímica em materiais, influenciados por atributos litológicos relativos a composição mineralo-química e estrutural do material parental. Para tanto foram descritos e amostrados 15 perfis de alteração; compostos por solo, saprolito e rocha, derivados de rochas sedimentares e metamórficas na região Sudeste do Brasil, nos estados de São Paulo e Minas Gerais. As descrições demonstraram que os corpos saprolíticos avaliados podem ser agrupados em quatro tipos morfológicos principais, sendo propostas as seguintes categorias estruturais: contínua, fraturada, fragmentada e terrosa. Dentre todos saprolitos avaliados, aqueles derivados de rochas metamórficas apresentaram maior complexidade morfológica. Deste modo, 9 perfis filiados a xistos e gnaisses foram submetidos a análises físicas, geoquímicas e mineralógicas para avaliação dos processos de alteração e desenvolvimento de sistema de classificação. A composição mineralógica de solos e saprolitos se mostrou semelhante, entretanto, ocorreram dissimilaridades geoquímicas entre estes corpos. Atributos físicos como densidade e porosidade total não demonstraram diferenças significativas entre solo e saprolito, entretanto, ao se considerar isoladamente amostras de saprolito, houve correlação positiva entre a perda de massa e a porosidade total, tornando este último atributo útil `a proposta de classificação de saprolitos. / The saprolite is a geological body constituted by the mixture of primary and secondary minerals resulting of physical and chemical weathering, which retains traces of the original rock structure. It differs from the soil by the evident litogenetic affiliation and insignificant biological activity. Although the definitions, however, the limit and the distinction between soil and saprolite are not always clear, because the continuity between these bodies in terms of hydrological and geochemical processes, as well as their physical and mineralogical compositions, which creates great confusion in morphological descriptions and information network. Due to the multidisciplinary nature of the sciences involved and the partial dedication of all of them in the saprolite investigations, there is a great lack of standardization of terms and procedures for characterization and analysis. The overall objective of this thesis is the characterization of saprolite developed from various lithologies in order to draw up procedures for the description, classification and saprolite analysis. Specifically aimed to evaluate in detail the patterns of physical, mineralogical and geochemical changes in some materials influenced by lithological attributes how the mineralogical and chemical composition, as well as the structure of parental material. For this were described and sampled 15 weathering profiles, composed of soil, saprolite and rock derived from sedimentary and metamorphic rocks in southeastern Brazil, in the states of São Paulo and Minas Gerais. The descriptions shown that saprolite evaluated can be grouped into four main morphological types, proposed the following structural categories: continuous, fractured, fragmented and earthy. Among all evaluated saprolite, those derived from metamorphic rocks showed higher morphological complexity. Thus, 9 affiliated profiles schists and gneisses to have been subjected to physical, geochemical and mineralogical analyzes to evaluate the change processes and to developing the classification system of saprolites. The mineralogical composition of soils and saprolite was similar, however, there were dissimilarities regard geochemical attributes between this bodies. Physical properties such as density and porosity showed no significant differences between soil and saprolite, however, when considered in isolation saprolite samples, there was a positive correlation between weight loss and total porosity, making this last attribute able to integrate the proposed saprolite classification.

As rochas vulcânicas da Mina do Seival possuem intensa alteração hidrotermal e mineralizações de Cu. Este magmatismo é relacionado ao estágio póscolisional do ciclo Brasiliano-Pan-Africano, no alogrupo Bom Jardim, pertencendo à Formação Hilário na Bacia do Camaquã (Neoproterozóico). A região já foi responsável por grande parte da produção desse minério no Brasil, sendo uma das mais importantes no Rio Grande do Sul e explorada principalmente na primeira metade do século XX. Campanhas de sondagens realizadas pela CBC foram feitas no ano de 1978. Essas amostras foram incluídas no presente trabalho bem como a amostragem resultante das campanhas de mapeamento geológico básico. A tectônica do estagio pós-colisional controla o posicionamento e geração da mineralização através de estruturas rúpteis com direção NE e distensão regional. A composição de rocha total e identificação dos minerais de alteração foram obtidas através de análises de elementos maiores, menores, traços e difração de raios X. Processos envolvendo diferentes temperaturas atuaram sobre estas rochas originando produtos de alteração pervasiva, principalmente clorita e esmectita, com veios preenchidos por quartzo, carbonato, barita e minerais de cobre. A Mina do Seival é composta pelas minas Alcides, Cruzeta, Meio, Morcego, João Dahne, Barita e ocorrência Vila do Torrão. As rochas vulcânicas tem composição andesítica e traqui-andesítica, e foram divididas em duas sequências. A sequência I é composta por rochas piroclásticas e efusivas, e a sequência II é representada pelos diques de andesito. Em ambas as sequências da Mina do Seival é possível identificar a afinidade shoshonítica das rochas. Os teores de Cu, Zn e Ni em relação ao protólito menos afetado pelo processo hidrotermal, nos diques e brechas, sugerem que as principais ocorrências de mineralização de cobre têm origem magmática. O estudo petrogenético contribui para a geração de um modelo evolutivo dos processos de alteração hidrotermal possibilitando o entendimento da geologia regional e das mineralizações da Bacia do Camaquã. / Volcanic rocks of the Seival Mine have intense hydrothermal alteration and Cu mineralization. This magmatism is related to post-collisional stage of the Brasiliano Pan-African cycle in Bom Jardim alogrup, belonging to Hilario Formation, Camaquã Basin (Neoproterozoic). The region has been responsible for much of the ore production in Brazil, one of the most important in the Rio Grande do Sul and operated mainly in the first half of the twentieth century. Drilling surveys conducted by CBC (Companhia Brasileira do Cobre) were made in 1978. Drill core samples, as well as field samples were used for the present research. The tectonics of the postcollisional stage controls the position and mineralization through brittle structures with NE and regional distention. Whole rock composition and identification of alteration minerals were obtained through analysis of major, minor and trace elements, and Xray diffraction. Processes involving different temperatures acted on these rocks causing pervasive alteration products, mainly chlorite and smectite, with veins filled with quartz, carbonate, barite and copper minerals. Seival Mine of Alcides, Cruzeta, Meio, Morcego, João Dahne, Barita mines and Vila do Torrão ocurrence. Volcanic rocks have andesitic and trachy-andesitic composition, and were divided into two sequences. The sequence I is composed of pyroclastic rocks and effusive, and sequence II is represented by andesite dikes. In both sequences of Seival Mine is possible to identify the shoshonitic affinity of the rocks. Cu, Zn and Ni are less affected by hydrothermal processes, relative to the protholith. Dykes and breccias, suggest that the main copper mineralization ocurrences have a magmatic origin. The petrogenetic study contributes to the generation of an evolutionary model of hydrothermal alteration allowing for better understanding of the regional geology and mineralization of Camaquã Basin.

Esta dissertação tem como tema a onerosidade excessiva no direito civil brasileiro. Primeiramente, fazem-se necessários uma noção inicial da figura, uma delimitação conceitual do problema e uma síntese de seu desenvolvimento histórico no direito civil brasileiro. Feito isso, são apresentadas as teorias utilizadas para sua fundamentação pela doutrina e pela jurisprudência brasileiras antes do advento de texto legal expresso sobre a matéria. Concluída essa fase preparatória, adentra-se no direito positivo vigente, precisamente no Código Civil, para explicar o conteúdo da onerosidade excessiva, de seus pressupostos e de suas conseqüências. São diretamente estudados os artigos 478, 479, 480, 317 e ainda outros específicos de alguns tipos contratuais. São abordados ainda alguns tópicos correlatos que finalizam o entendimento da matéria, como os pressupostos negativos da figura, sua incidência em contratos de sinalagma indireto e nos contratos aleatórios e as diferenças nos pressupostos para sua configuração no Código de Defesa do Consumidor. / The theme of this dissertation is known in english as hardship, which means the fundamental alteration of the equilibrium of the contract. Firstly, it is necessary to make an introductional notion of the figure, a conceptual delineation of the problem and a summary of its historical evolution in the brazilian civil law. After that, it is presented the theories used by authors and courts to reason the solution of the problem before the existence of legal text about the issue. Then, we study the related articles of the Brazilian Civil Code to explain the content of hardship, the content of its requirements, and the content of its consequences. The articles 478, 479, 480, 317 are directly studied, and also other articles from particular named contracts. Some related issues finalize the understanding of the theme, as the negative requirements of the figure, its incidence in some particular categories of contracts, and the difference of its requirements in the Consumer Defense Code.

A Província Mineral de Carajás, situada a sudeste do Cráton Amazônico, concentra a maior parte dos depósitos de óxido de ferro-cobre-ouro (IOCG) de alta tonelagem do mundo. Apesar da grande quantidade de estudos geocronológicos, os atributos geológicos, assinaturas isotópicas e fatores responsáveis pela formação dessas grandes reservas minerais ainda são pouco compreendidos. O depósito Furnas (500 Mt @ 0,7% Cu) constitui um trend mineralizado de direção WNW-ESSE, com 9 km de extensão, situado na Falha Transcorrente do Cinzento. Apresenta expressiva relação espacial com dois corpos graníticos: o granito Cigano, paleoproterozoico, aflorante a leste, e o granito Furnas, de idade incerta e mais preservado da alteração hidrotermal apenas a oeste do depósito. As rochas hospedeiras são representadas por andalusita-muscovita-biotita xisto com estaurolita na zona de lapa e por anfibólio-granadabiotita xisto na zona de capa. A paragênese metamórfica do anfibólio-granada-biotita xisto é representada por núcleos de Fe-edenita com bordas hidrotermais de Fe-tschermakita, K-hastingsita, Fe-actinolita e K-Fesadaganaíta. Resquícios do granito Furnas, intensamente hidrotermalizados, são reconhecidos, com dificuldade, nos testemunhos de sondagem. Distintos estágios de alteração hidrotermal estão impressos nas rochas. O granito Furnas foi o único submetido à alteração sódica pervasiva inicial (albitização), sucedida por intensa silicificação, concomitante à milonitização e posterior alteração potássica (biotita), registradas, também, nas demais hospedeiras do depósito. Turmalinização posterior a concomitante à alteração potásica, foi sucedida pela cristalização de cristais milimétricos de almandina, comumente coalescentes, associados a frentes de alteração hidrotermal. O metassomatismo de ferro é representado pela formação de grunerita, seguida por cristalização de magnetita ao longo da xistosidade das rochas hospedeiras. Estágio hidrotermal tardio originou rochas grossas e isótropas a localmente foliadas, constituídas principalmente por K-hastingsita associada a halos externos de alteração clorítica e veios de quartzo, comumente mineralizados. Chamosita formada nesse estágio substituiu parcial a totalmente biotita, granada e anfibólios formados em estágios prévios. A mineralização, representada por calcopirita e bornita, ocorre em fronts de substituição nas rochas ricas em granada-grunerita-magnetita, em veios e vênulas interconectadas, configurando stockworks. Além disso, brechas com infill de sulfetos que contornam clastos constituídos por quartzo, possivelmente associado à eventos de silicificação prévios, são identificadas. Mineralização de cobre, subordinada e tardia, se associa a veios de quartzo-hastingsita-clorita-albita-carbonato, com texturas de preenchimento de espaços abertos, relacionados espacialmente às zonas de cloritização. As paragêneses reconhecidas nos distintos estágios, principalmente àquelas relacionadas à zona mineralizada, constituem uma assembleia de alta a moderada temperatura para o sistema hidrotermal relacionado à evolução do depósito Furnas. Os estilos de alteração relacionam-se a diferentes regimes deformacionais e níveis crustais, demonstrando sobreposição de eventos mineralizantes e de alteração em sistemas hidrotermais intermediários, tal qual o Furnas. / The Carajás Mineral Province, located at the southern portion of the Amazonian Craton, hosts great part of the high-grade iron-oxide-copper-gold deposits known in the world. Despite the significance of geochronological studies, the geologic features, isotopic signatures and processes responsible for the formation of these outstanding mineral resources is still poorly understood. The Furnas deposit (500 Mt @ 0.7% Cu) comprises a mineralized WNW-ESSE trend, with 9 km of extension, within the Cinzento Transcurrent Fault Zone. The deposit has notable spatial relationship with two granitic bodies: the Paleoproterozic Cigano granite, which outcrops at the east; and the Furnas granite, of uncertain age, that is well-preserved from the hydrothermal alteration only outcrops towards the west. The host rocks are represented by andalusite-muscovite-biotite schist with staurolite at the footwall and amphibole-garnet-biotite schist at the hanginwall zone. The metamorphic paragenesis of the amphibolegarnet-biotite schist is represented by Fe-edenite cores, which are rimmed by hydrothermal Fe-tschermakite, K-hastingsite, Fe-actinolite and K-Fe-sadaganaite. Relicts of the Furnas granite, highly hidrothermalized, can be barely recognized at the drillholes. Different stages of hydrothermal alteration are recognized in the Furnas Deposit. The Furnas granite underwent an early pervasive sodic alteration with albite. This was succeeded by intense silicification synchronous to milonitization, which was followed by potassic alteration with biotite, also recorded on the other host rocks. Turmalinization, later to coeval to potassic alteration, was followed by the crystallization of milimetric almandine crystals, generally coalescing, associated with hydrothermal alteration fronts. Iron metassomatism is represented by grunerite crystallization, followed by magnetite formation along the host rock foliation. A later hydrothermal stage originated coarse-grained rocks, isotropic to locally foliated, composed mainly of K-hastingsite associated with external haloes of clorite alteration and quartz veins, generally with copper mineralization. Chamosite, formed at this stage, replaced partial to totally biotite, garnet and amphiboles formed in previous hydrothermal alteration stages. Copper-gold mineralization is represented by chalcopyrite and bornite, which occur in replacement alteration fronts in the garnet-grunerite-magnetite-rich rocks, in veins, interconnected veinlets and stockworks. Besides that, breccias with sulfide infills that surround quartz clasts, probably associated with early silicification events, are also recognized. Late and subordinated copper mineralization is associated with quartz-hastingsite-chlorite-albite-carbonate veins with open-space filling textures that are spatially related to chlorite zones. The paragenesis of the distinct hydrothermal alteration stages, especially those related to the mineralized zone, constitute high to moderate temperature mineral assemblage formed in the Furnas hydrothermal system. Alteration styles are related with different deformation regimes and crustal levels, demonstrating overprinting of mineralizing and hydrothermal alteration events in intermediate hydrothermal systems, as the Furnas.

Graduate teaching associates (GTAs) maintain a prominent presence in higher education institutions nationwide, warranting our attention to both their instructional effectiveness and well-being. Though they remain an integral part of higher education, the training practices implemented for GTAs often fall short in addressing all of the needs posed by the role GTAs fulfill. The shortcomings in training often stem from an overemphasis of basic teacher preparation skills (such as syllabus creation, lesson planning, and grading) and university/departmental policies, as well as a lack of attention to teaching effectiveness and skills on managing uncertainties and identity concerns in their unique role. In the hopes of filling existing gaps in the training of GTAs, offered here is a supplemental guide that seeks to satisfy the needs of GTAs, regardless of the discipline within which they teach. The salient needs of GTAs can be classified as either task or self concerns. The GTA task concerns identified in this work stem from the want to be "good" and effective teachers, who are not only well-liked by students, but who are also successful at promoting learning, motivating students, and managing the classroom effectively. In addressing these task concerns, this work introduces readers to instructional communication-based concepts/constructs, specifically teacher immediacy and behavior alteration techniques (BATs) and messages (BAMs), along with practical means by which GTAs can utilize them in the classroom. Self concerns experienced by GTAs, such as role conflict due to managing multiple identities, impostor phenomenon, and teacher self-efficacy, are also addressed here, in addition to practical means by which GTAs can reduce uncertainties through taking an active role in the socialization process.

Le chanci est une altération récurrente des peintures de chevalet à l’huile, induite par l’humidité. Elle affecte les vernis et les couches picturales. Selon le degré d’altération, la couche picturale peut être partiellement ou totalement masquée par un voile blanchâtre. L’analyse d’environ 50 micro-prélèvements altérés et non altérés par microscopie électronique à effet de champ a révélé une structure poreuse dans les vernis et les couches picturales altérées, avec une taille de pores comprises entre 50 nm et 4 µm. Pour les chancis de couches picturales, des investigations complémentaires par nanotomographie X à contraste de phase ont démontré que les pores étaient localisés dans le liant. L’apparence visuelle des couches altérées est due à la diffusion de la lumière par les pores, ce qui a été corroboré par des simulations numériques. Un modèle physico-chimique a été proposé pour expliquer la formation des pores. Il repose sur le fait que les vernis et les liants lipidiques peuvent être assimilés à des ionomères dans lesquels les acides carboxyliques et les carboxylates métalliques ségrègent pour former des clusters ioniques. En présence d’humidité, les clusters s’hydratent entraînant la formation de régions aqueuses. Lors de la phase de déshydratation, les pores initialement remplis d’eau se vident mais subsistent. L’apparition des chancis de vernis et de couches picturales est donc directement liée à la quantité d’acides et à leur capacité à former des clusters.Les traitements de restauration seront efficaces et durables, si et seulement s’ils résorbent ou comblent durablement les pores, dans le but de réduire la diffusion de la lumière. Pour les chancis de couches picturales, les traitements actuels sont peu satisfaisants. Un nouveau traitement innovant a été développé et testé sur des échantillons modèles et des peintures anciennes chancies. Les résultats sont très prometteurs en termes de stabilité, d’efficacité, de durabilité et de réversibilité. Cette recherche aura incontestablement un impact majeur, puisqu’elle pourrait répondre à un véritable besoin pour la restauration et la conservation des peintures de chevalet chancies. / Blanching of easel oil paintings is a recurrent alteration, induced by humidity. It affects varnish and paint layers. Depending on the degree of alteration, the paint composition can be partially or totally hidden by a whitish haze. The analysis of circa 50 altered and unaltered paint micro-samples by field-emission gun scanning electron microscopy revealed a highly porous structure in both varnish and paint altered layers, with pores ranging in size from 50 nm to 4 µm. Regarding the blanching of paint layer, in-depth investigation performed by X-ray phase contrast nanotomography highlighted that pores are located in the binder. The visual appearance of altered layers is due to the light scattering by the pores, which was corroborated by computational modeling.A physico-chemical model was proposed to explain the pores formation. It is based on the fact that the varnish and the lipidic binder can be assimilated to ionomers, where carboxylic acids and metal carboxylates segregate to form ionic clusters. In a humid environment, the clusters get hydrated inducing the formation of aqueous regions. During the dehydration, the water is drained out from them, but the pores remains. The blanching emergence is thus directly linked to the quantity of acids and their ability to form clusters. Conservation treatments will be efficient and sustainable only if they resorb or durably fill the pores, in order to reduce the light scattering. For the blanching of paint layers, current treatments are not very effective over time. A new innovative treatment has been developed and tested on mock-ups and ancient altered paintings. The results are very promising in terms of stability, efficiency, durability and reversibility. This research will undoubtedly have a major impact, fullfilling a real requirement for the conservation of blanched easel oil paintings.

The extensive clearing and modification of natural systems from anthropogenic activities is a pressing global concern. Forest habitats and animal communities within forests are among the most highly impacted, globally. Forest destruction has been repeatedly documented as a driver of biodiversity loss. However, little is known about how animal communities respond when altered landscapes are abandoned and left to regenerate into secondary forests. It is thought that the regrowth of secondary forests may help reverse biodiversity loss by restoring habitats to similar conditions as prior to land conversion. Of the forest cover that remains, over half is secondary forest, and in many countries secondary forest cover has been steadily increasing. Therefore, it is important to understand how and if faunal communities recover during secondary forest regeneration. I combined meta-analytic, field-survey-based, and lab-based experimental techniques to determine how amphibians and reptiles respond to habitat change in general, and secondary forest regeneration on landscapes previously cleared for use as pasture. I addressed five specific questions: 1) what are the effects of habitat alteration on amphibians and reptiles?, 2) what are the effects of secondary forest succession on amphibians and reptiles?, 3) what is the relative importance of stochastic and deterministic effects on community assembly during secondary forest succession?, 4) how do amphibian and reptile species composition, probability of occurrence, and species richness change over the course of secondary forest succession?, and 5) is thermal quality of habitat an important mechanism of species response to secondary forest succession? I found that secondary forest has high conservation value for many amphibian and reptile species, environmental changes associated with secondary forest succession have a significant effect on shaping amphibian and reptile community composition, thermal quality is an important mechanism for species response and that strength of response is mediated by species-specific thermal biology. I also highlight the importance of riparian corridors in maintaining species diversity in modified habitats.

Malignant glioma have poor prognosis resulting mainly from high level of cell proliferation and invasion and resistance to conventional therapy. Identification of novel targets that are critical elements in gliomagenesis may help improve therapeutic outcome. Using genome-wide explorations of a comprehensive glioma specimen population, we identified whole gain of chromosome 19 as one of the major chromosomal aberrations in high grade glioma that correlates to patients' outcomes. Our analysis revealed for the first time NOTCH3 as one of the most significant gene amplifications mapped to chromosome 19. This amplification is associated with worse outcome compared to tumors with non-amplified locus. NOTCH signaling pathway is essential for cell proliferation, stem cell maintenance and differentiation and its deregulation has been reported in several human cancers. NOTCHs are key positive regulators of cell-cell interactions, angiogenesis, cell adhesion and stem cell niche development which have been shown to play critical roles in gliomagenesis and glioma drug resistance. Our objective is to determine NOTCH3 molecular roles in glioma pathogenesis and aggressiveness. Here we show for the first time that NOTCH3 plays a role in glioma cell proliferation, cell migration, invasion and apoptosis. We also found a NOTCH3 glioma addiction phenomenon. Therefore, our study uncovers, for the first time, the prognostic value and the oncogenic function of NOTCH3 in gliomagenesis and supports NOTCH3 as a promising target of therapy in high grade glioma. Our studies allow the identification of a subset of population that may benefit from GSI-based therapies. This may lead to the design of novel strategies to improve therapeutic outcome of patients with glioma by establishing medical and scientific basis for personalized medicine.