Résumé confidentiel / Not available

Cette thèse en partenariat industriel s’intéresse aux peintures polyuréthane et époxy utilisées à des fins protectrices pour des applications ferroviaires. L’objectif de ce projet est de développer de nouveaux additifs spécifiques à ces peintures afin d’améliorer les propriétés mécaniques et adhésives des films sur acier, tout en gardant une bonne dispersion des charges minérales présentes dans la formulation. Des additifs polymères ont été développés. Ces polymères miscibles avec la résine ont été synthétisés par polymérisation cationique (technique du monomère activé) ou anionique coordinée, et présentent différents degrés de polymérisation. Ces polymères sont fonctionnalisés d’une part par un groupement réactif vis-à-vis des charges minérales afin d’assurer leur dispersion, et d’autre part par un groupement réactif vis-à-vis de la résine (polyuréthane ou époxy) afin d’optimiser les propriétés mécaniques des films finaux par ancrage des charges au réseau. Des études par analyses thermogravimétrique et granulométrie laser ont permis de sélectionner les additifs les plus pertinents et de mettre en évidence leur efficacité sur la désagglomération des charges, notamment par rapport aux dispersants commerciaux actuellement utilisés. Des essais mécaniques sur des films de peintures libres ont montré l’impact positif des additifs sur les propriétés mécaniques et adhésives des films sur acier, tant pour les peintures polyuréthane que pour les peintures époxy. Ces nouveaux additifs jouent donc le rôle d’agent dispersant et de promoteur d’adhésion. / Polyurethane and epoxy paints are used in rail applications for protective purposes. The aim of this Ph.D thesis was to develop new additives to improve mechanical and adhesive properties of polyurethane and epoxy paints on steel, keeping good dispersion of pigments and fillers present in paint formulation. Additives were designed as dispersing agents. A polymer which is miscible with the resin paint is synthesized by ring-opening polymerization with different polymerization degrees. Post-modifications were realized to introduce reactive functions ensuring the dispersion of fillers and pigments, and to optimize mechanical properties of paint films (anchoring fillers and pigment to the resin). Thermogravimetry analysis and dynamic light scattering were used to select the best additives and to underline their efficiency on the deagglomeration of pigments and fillers, especially compared to commercial dispersing agents currently used. Mechanical tests highlight that new additives enhanced mechanical and adhesives properties of paint films on steel, both for polyurethane and epoxy paints. Additives, designed as coupling agents, are used at as dispersing agents and adhesion promoters.

A influência de variáveis do banho na composição, microestrutura e nas propriedades magnéticas de filmes de CoB preparados por deposição química foi estudada. Dois diferentes tipos de agentes complexantes foram utilizados: citrato de sódio e Glicina. Filmes com menor teor de boro foram obtidos com o uso de Glicina como complexante. A deposição de Co é acelerada em presença de Glicina ou de amônia no banho, porque ambos evitam a diminuição do pH na interface solução/filme de CoB em crescimento. A coercividade dos filmes variou em função do teor de boro, sendo que filmes com maior teor de boro apresentaram mais baixa coercividade. Catalisadores de Co/Al2O3 são utilizados na síntese de combustíveis à partir de derivados do Gás Natural (Síntese de Fischer-Tropsch - SFT). O processo usual de preparação destes catalisadores, denominado impregnação úmida, consiste na impregnação do substrato em solução de sal de Co(II), secagem/calcinação e redução com H2 a 300/350 °C. Uma fração considerável do Co não é reduzida à fase metálica na etapa de redução, o que resulta em perdas de área ativa para a catálise da SFT. Normalmente pequenas quantidades de metais preciosos tais como Pt, Ru ou Pd são adicionadas para catalisar a redução dos óxidos de cobalto e aumentar a área superficial ativa do catalisador, o que representa um grande incremento no custo destes catalisadores. Nesta tese, foram investigadas duas propostas alternativas de solução para este problema: a preparação de catalisadores de Co por deposição química sobre Al2O3 e a preparação pelo método usual, mas com adição de pequenas quantidades de Cu,Ag e Au, dos quais Cu e Ag têm custo mais baixo do que os metais preciosos normalmente utilizados. Co foi depositado quimicamente sobre γ-Al2O3, previamente ativada com pequenas quantidades de Pd, utilizando NaBH4 como redutor. Uma amostra de catalisador de CoB/PdAl2O3 (contendo 13,4 % em massa de Co e c.a. 25% at. de boro) foi obtida e caracterizada por RTP, Quimissorção de H2 e XRD, assim como foram efetuados testes de SFT sob diferentes temperaturas de ativação. Para efeito de comparação, foi preparado por impregnação úmida uma amostra de Co/PdAl2O3 contendo 11% em massa de Co, sobre a mesma alumina ativada com Pd utilizada na preparação dos catalisadores de CoB/PdAl2O3. Embora a amostra de catalisador de CoB/PdAl2O3 tenha tido menor área superficial ativa do que a amostra de catalisador de Co/PdAl2O3, sua atividade catalítica foi sensivelmente maior. Essa diferença pode ser explicada supondo-se que o boro é solubilizado durante a reação, deixando uma fase de Co metálico altamente dispersa. Catalisadores de Co/Al2O3 promovidos por metais do grupo 11 foram preparados por impregnação úmida. Além da caracterização por RTP, Quimissorção de H2/titulação de O2 e XRD, a estrutura das amostras de catalisador foi estudada por XANES/EXAFS. Dos resultados de EXAFS e do fato de que altos teores de Cu e Au levaram à desativação do catalisador, é sugerido que durante a redução, o promotor é segregado para a superfície das partículas de Co. Dos três metais testados, Ag e Au apresentaram maior efeito promotor da atividade catalítica, proporcionando maior área superficial ativa para catálise da SFT. Não houve modificações importantes na seletividade dos catalisadores por conta da presença destes metais. / The influence of bath composition on the boron content, microstructure and magnetic properties CoB films deposited by chemical deposition was studied. Two different complexing agents were used in this study: sodium citrate and Glycine. CoB films with lower boron content were obtained with the use of a Glycine containing bath. The Co deposition is accelerated when either Glycine or ammonia is present in the solution because both substances prevent the decrease of the pH in the region near the CoB film/solution interface. The coercivity of the films varied in function of the boron content, as films with larger boron contents showed lower coercivities. Co/Al2O3 is used as a catalyst for the synthesis of liquid fuels from either coal or natural gas derivatives (Fischer Tropsch Synthesis FTS). The usual preparation procedure of such catalysts, known as wet impregnation, consists in the Al2O3 impregnation with a Co(II) aqueous solution, water evaporation/calcination and reduction with H2 at 300/350 °C. A considerable fraction of the cobalt oxides formed during calcination is not reduced to Co0 during reduction and this leads to active area loss. Normally, small quantities of precious metals like Pt, Ru or Pd are added to promote the reduction of cobalt oxides and therefore increase the active area of the Co/Al2O33 catalyst, yet these metals are extremely expansive. In this thesis, two different approaches to solve this problem are presented: the preparation of Co/Al2O3 by chemical deposition of the metallic phase and the use of Cu, Ag or Au (from which, Cu and Ag are cheaper metals) as promoters on wet impregnation prepared Co/Al2O3 catalysts. Cobalt was chemically deposited on γ-Al2O3, activated with a small quantity of Pd, with NaBH4 as a reducing agent. The resulting CoB/PdAl2O3 sample (with 13,4 % wt. Co and approximately 25 % at. of boron) was characterized by TPR, H2 Chemisorption and XRD, as well as SFT tests were made with the catalyst at different pre-reduction temperatures. For the sake of comparison a Co/PdAl2O3 catalyst sample with almost the same Co loading (11 % wt.) was prepared by wet impregnation on the same Pd-activated Al2O3 used to prepare the CoB/PdAl2O3 sample. Although the CoB/PdAl2O3 has a smaller active surface area (measured by H2 Chemisorption) than that of the Co/PdAl2O3 sample, it presented a much higher catalytic activity for the SFT. This difference may be explained assuming that boron impurities (present in the catalyst as boron oxides) is solubilized during the reaction leaving a highly dispersed Co phase. Group 11 promoted Co/Al2O3 catalysts were prepared by wet impregnation and characterized by TPR, H2 Chemisorption/O2 pulse oxidation, XRD and XANES/EXAFS. From the EXAFS results and from the fact that higher loadings of Cu and Au lead to catalyst deactivation, it is proposed that in the reduced catalyst the SFT inactive promoter is segregated to the surface. Silver and Gold were the most active in promoting Co reduction and therefore increasing catalytic activity for the SFT. No important modification in the selectivity of the reaction was observed.

O uso de antimicrobianos como promotores do crescimento na alimentação animal tem proporcionado uma melhora considerável no desempenho animal. Porém, seu uso vem sendo proibido em diversos países e, face a esta restrição, tem-se buscado alternativas aos antimicrobianos promotores do crescimento. Assim, o objetivo do trabalho foi avaliar extratos vegetais como alternativas aos antimicrobianos promotores do crescimento de leitões recémdesmamados, por meio do desempenho e da morfometria de órgãos dos animais. Um experimento em blocos casualizados, com 35 dias de duração, foi realizado para testar cinco tratamentos: controle - ração basal; antimicrobiano - basal com colistina + tiamutin (75 ppm de cada); extrato de cravo (Ec) - basal com 420 ppm de extrato vegetal (210 ppm de óleo essencial de cravo + 210 ppm do princípio ativo eugenol); extrato de orégano (Eo) - basal com 420 ppm de extrato vegetal (210 ppm de óleo essencial de orégano + 210 ppm do princípio ativo carvacrol) e extrato de cravo + orégano (E c+ Eo) - basal com 420 ppm de extrato vegetal (105 ppm de óleo essencial de cravo + 105 ppm de eugenol e 105 ppm de óleo essencial de orégano + 105 ppm de carvacrol), sendo todos os extratos vegetais encapsulados. Para o desempenho, foram utilizados 80 leitões, com idade média em torno de 24 dias e peso inicial de 7,19 ± 1,55, oito repetições por tratamento e dois animais por unidade experimental. Ao final do período experimental, um animal de cada baia, dos quatro primeiros blocos, foi abatido para morfometria de órgãos. Foram testados contrastes específicos de importância prática. No período de 1 a 14 dias, animais do tratamento antimicrobiano apresentaram melhor conversão alimentar (CA) que a média dos animais dos tratamentos com extratos (P=0,02), enquanto que animais do tratamento Ec apresentaram melhor CA que os do tratamento Eo (P=0,03). No período total, os animais do tratamento antimicrobiano apresentaram maior peso aos 35 dias (P35) (P=0,05) e ganho diário de peso (GDP) (P=0,06) que a média dos animais dos tratamentos com extratos. Os animais do tratamento Ec + Eo apresentaram maior P35 (P=0,02) e GDP (P=0,02) em relação à média dos animais dos outros tratamentos com extratos. Para a morfometria de órgãos os antimicrobianos proporcionaram maior peso relativo dos rins (P=0,01) em relação aos outros tratamentos de extratos. De modo geral, os antimicrobianos proporcionaram os melhores desempenhos de leitões em fase de creche. Quanto aos extratos vegetais, a combinação de Ec + Eo acarretou um desempenho muito próximo àquele obtido com os antimicrobianos, demonstrando ser uma alternativa promissora como promotor do crescimento de leitões recém-desmamados. / The use of antimicrobial as growth promoters in the animal feed has been related to an increase on animal performance. However, due to the restriction of many countries to the use of antimicrobial as growth promoters, alternatives are being studied. So, the purpose of this work was to evaluate herbal extracts as alternatives to antimicrobial growth promoters of weanling pigs based on performance and organ weights. A 35-d randomized complete block design experiment was carried out to compare five treatments: control - basal diet; antimicrobial - basal diet with colistin + tiamutin (75 ppm of each); herbal extract of clove (Ec) - basal diet with 420 ppm of herbal extract (210 ppm of essential oil of clove + 210 ppm of active compound eugenol); herbal extract of oregano (Eo) - basal diet with 420 ppm of herbal extract (210 ppm of essential oil of oregano + 210 ppm of active compound carvacrol); and herbal extract of clove + oregano (Ec + Eo) - basal diet with 420 ppm of herbal extract (105 ppm of essential oil of clove + 105 ppm of eugenol and 105 ppm of essential oil of oregano + 105 ppm of carvacrol ), being all the herbal extracts encapsulated. Eighty pigs (average age around 24 d and initial live weight of 7.19 ± 1.55 kg), eight replications per treatment, and two animals per experimental unit were used for performance data. At the end of experimental period, an animal per pen of first four blocks was slaughtered for organ morphometry data. Specific contrasts of practical importance were tested. For 1-14 d period, pigs fed antimicrobial showed better fed conversion (CA) than the mean of those fed herbal extract treatments (P=.02), while pigs fed Ec gave better CA than those fed Eo (P=.03). For the total period, pigs fed antimicrobial showed higher body weight at 35 days (P35) (P=.05) and average daily gain (GDP) (P=.06) than the mean of those fed herbal extracts. Pigs fed Ec + Eo gave higher P35 (P=.02) and GDP (P=.02) than the mean of those fed other herbal extract treatments. For the organ morphometry data, the antimicrobials provided a higher relative weight of kidneys (P=.01) than the mean of the other treatments with herbal extracts. Overall, antimicrobial agents provided the best performance of weanling pigs. Concerning to herbal extracts, the combination of clove and oregano provided performance close to that of pigs fed antimicrobials, showing that this combination can be a potential alternative as growth promoter of weanling pigs.

Chloroplasten höherer Pflanzen haben kleine Genome. Trotzdem ist ihre Transkriptionsmaschinerie sehr komplex. Plastidäre Gene werden von plastidenkodierten (PEP) und kernkodierten RNA-Polymerasen (NEP) transkribiert. In der vorliegenden Arbeit wurden Promotoren plastidärer Gene und Operons von Arabidopsis thaliana charakterisiert. Zur Unterscheidung zwischen NEP- und PEP-Promotoren wurden erstmals spectinomycinbehandelte, chlorophylldefiziente Arabidopsis-Pflanzen mit fehlender PEP-Aktivität verwendet. Obwohl für einige Gene auch einzelne Promotoren lokalisiert wurden, wird die Transkription der meisten plastidären Gene und Operons an multiplen Promotoren initiiert. Der Vergleich plastidärer Promotoren von Tabak und Arabidopsis zeigte eine hohe Vielfältigkeit der Promotornutzung, die möglicherweise auch in anderen höheren Pflanzen vorkommt. Dabei stellt die individuelle Promotornutzung eine speziesspezifische Kontrollmöglichkeit der plastidären Genexpression dar. Das Kerngenom von Arabidopsis beinhaltet zwei Kandidatengene der NEP, RpoTp und RpoTmp, welche Phagentyp-RNA-Polymerasen kodieren. In der vorliegenden Arbeit wurde die Wirkung veränderter RpoTp-Aktivität auf die Nutzung von NEP- und PEP-Promotoren in transgenen Arabidopsis-Pflanzen mit verminderter und fehlender RpoTp-Aktivität untersucht. Im Keimlingsstadium konnten Unterschiede in der Promotornutzung zwischen Wildtyp und Mutanten beobachtet werden. Fast alle NEP-Promotoren wurden in Pflanzen mit verringerter oder fehlender RpoTp-Aktivität genutzt. Dabei zeigten nur einige von ihnen eine geringere Aktivität, andere wiederum waren sogar verstärkt aktiv. Der starke NEP-Promotor des essentiellen ycf1 Gens wurde in jungen Keimlingen ohne funktionelle RpoTp nicht genutzt. Die Ergebnisse zeigen, dass NEP gemeinsam von beiden Phagentyp-RNA-Polymerasen RpoTp und RpoTmp repräsentiert wird und dass beide sowohl eine überlappende, als auch eine spezifische Rolle in der Transkription plastidärer Gene innehaben. / Although chloroplasts of higher plants have small genomes, their transcription machinery is very complex. Plastid genes of higher plants are transcribed by the plastid-encoded plastid RNA polymerase PEP and the nuclear-encoded plastid RNA polymerases NEP. Here, promoters of plastid genes and operons have been characterized in Arabidopsis thaliana. For the first time spectinomycin-treated, chlorophyll-deficient Arabidopsis plants lacking PEP activity have been used to discriminate between NEP and PEP promoters. Although there are plastid genes that are transcribed from a single promoter, the transcription of plastid genes and operons by multiple promoters seems to be a common feature. Comparison of plastid promoters from tobacco and Arabidopsis revealed a high diversity, which my also apply to other plants. The diversity in individual promoter usage in different plants suggests that there are species-specific solutions for attaining control over gene expression in plastids. The nuclear genome of Arabidopsis contains two candidate genes for NEP transcription activity, RpoTp and RpoTmp, both coding for phage-type RNA polymerases. In this study the usage of NEP and PEP promoters has been analysed in transgenic Arabidopsis plants with reduced and lacking RpoTp activity. Differences in promoter usage between wild type and mutant plants were most obvious early in development. Nearly all NEP promoters were active in plants with low or lacking RpoTp activity, though certain promoters showed reduced or even increased usage. The strong NEP promoter of the essential ycf1 gene was not transcribed in young seedlings without functional RpoTp. These results provide evidence for NEP being represented by two phage-type RNA polymerases RpoTp and RpoTmp that have overlapping as well as specific functions in the transcription of plastid genes.

Die Beschreibung genregulatorischer Ereignisse ist entscheidend um Zelldifferenzierung und -entwicklung zu verstehen. Dynamische Vernderungen der Chromatinstruktur, Histonmodifikationen und das Binden von Transkriptionsfaktoren an Enhancer und Promotoren, koennen mit Hilfe von genomweiten Hochdurchsatz-Sequenziertechniken wie ChIP-Seq, DNase-Seq, ATACSeqund RNA-Seq untersucht werden. In dieser Arbeit entwickele ich mehrere probabilistische Modelle fuer die Analyse von genomweiten Sequenzierungsdaten. Diese umfassen 1. einen Peak-Finder fuer ChIP-/DNase-/ATAC-Seq-Daten, der sich Replikate zunutze macht und praezise Peak-Weiten berechnet, 2. eine Pipeline um das Genom in hoher Aufloesung in eindeutige Klassen von Kombinationen von Histonmodifikationen zu segmentieren, 3. ein Bayes-Netzwerk-Modell welches multiple zeitlich aufgelste Histonmodifikations-ChIP-seq-Daten kombinatorisch clustert Klassen von regulatorischen Elementen zu identifizieren. Mit Hilfe dieser Modelle untersuchen wir die Promotorumgeben und zeigen einen Zusammenhang zwischen Chromatinstruktur und Promotordirektionalitaet. Darueber hinaus verwenden wir ein Modell zur direkten Reprogrammierung von Stammzellen in Motorneuronen durch die gezielte Expression von Transkriptionsfaktoren und analysieren die dadurch induzierten zeitlichen Vernderungen der Chromatinstruktur und Transkriptionsfaktorbindedynamik. Wir beobachten, dass Promotoren verschiedenen Chromatin-Dynamiken zur Aktivierung und Repression folgen, die mit den Chromatin-Dynamiken von Enhancer-Elementen korrelieren. Enhancer hingegen werden durch kooperatives Verhalten direkt induzierter Transkriptionsfaktoren und anderen Faktoren, die in den Stammzellen zu Beginn vorhanden waren oder im Verlaufe der Differenzierung aktiviert wurden, kontrolliert. Diese Arbeit zeigt wie wichtig Chromatin-Dynamik und ihre Beziehung zur Logik von Transkriptionsfaktoren ist, um die Veraenderungen der Genexpression zu verstehen. / Delineating transcription regulatory events is crucial to understand cell differentiation and development. Dynamic changes of chromatin structure, histone modifications and transcription factor binding to enhancers and promotors can be investigated with the aid of genome-wide high-throughput sequencing technologies such as ChIP-Seq, DNase-Seq, ATAC Seq and RNA Seq. In this thesis, I develop several probabilistic models for the analysis of genome-wide sequencing data. These include: 1. a peak finder for ChIP-Seq, DNase-Seq and ATAC Seq data, which exploits biological replicates and accurately demarcates peak widths, 2. a pipeline for high-resolution genome segmentation into unique classes of combinations of histone modifications and 3. a Bayesian network model that can co-cluster multiple time-course histone modification ChIP-Seq data sets into distinct classes of regulatory elements. With the aid of these models we investigate the promoter chromatin environment and show a link between chromatin state and transcription initiation directionality. In addition, we use a system for direct reprogramming of stem cells in motor neurons by the targeted expression of transcription factors to analyse changes in chromatin state and transcription factor dynamics during differentiation. We observe that promoters follow different chromatin dynamics for activation and repression that correlate with the chromatin dynamics of enhancer elements. Enhancers are controlled by cooperative behavior of directly induced transcription factors and other factors present in the stem cells initially, or activated in the course of differentiation. Overall, this work demonstrates the importance of understanding chromatin dynamics and their relationship to transcription factors logic in order to better explain changes in gene expression.

O objetivo dessa dissertação é apresentar as atividades, realizações, avaliações e resultados alcançados no I Curso de Capacitação para Promotoras Legais Populares do Estado do Tocantins (PLPs), que foi realizado pela Casa da Mulher Oito de Março, em Palmas – TO, no período de 10 de outubro de 2003 a 10 de dezembro de 2004. Procurou-se relatar e salvaguardar a memória de uma das mais importantes e completas atividades de formação de mulheres já ocorridas no Estado do Tocantins. O método utilizado para a coleta de dados seguiu os pressupostos da pesquisa histórica, com viés crítico e feminista, orientado pela análise sobre o empoderamento e a emancipação das mulheres, pelo acesso à justiça e a vivência em constantes debates sobre os Direitos Humanos. A partir de uma análise qualitativa dos dados coletados junto às participantes dos Cursos de Formação de PLPs com aplicação de questionários e depoimentos, a pesquisadora figurou como uma intérprete privilegiada pela Pesquisa Participante, responsável por reproduzir a linguagem, as palavras ou não-palavras ditas pelas participantes. Entende-se que a relevância social e profissional desta dissertação consiste em atender à necessidade de ampliar o alcance da educação em Direitos Humanos das mulheres, em descrever e valorizar a experiência já existente no Tocantins, apresentando as suas bases teóricas e práticas de atuação, além de trazer novos segmentos ao processo educativo, nova práxis educativa e instrucional aos cursos de Promotoras Legais Populares no Estado do Tocantins. / The objective of this dissertation is to present the activities, achievements, evaluations and results achieved in the 1st Training Course for Popular Legal Promoters of the State of Tocantins (PLPs), which was held by the Women 's House 8th March in Palmas - TO , in the period from october 10, 2003 to december 10, 2004. We sought to report and safeguard the memory of one of the most important and complete training activities for women already held in the State of Tocantins. The method used for the collection of data followed the presuppositions of historical research, with a critical and feminist bias, guided by the analysis of the empowerment and emancipation of women for access to justice and living in constant debates on Human Rights. Based on a qualitative analysis of the data collected from the participants of the PLP Training Courses with the application of questionnaires and statements, the researcher was a privileged interpreter of the Participant Research, responsible for reproducing the language, words or non-words spoken by the participants. It is understood that the social and professional relevance of this dissertation is to take into account the need to expand the reach of women's Human Rights education, to describe and value the experience already existing in Tocantins, presenting its theoretical bases and practices, in addition to bringing new segments to the educational process, a new educational and instructional praxis to the Popular Legal Promoters courses in the State of Tocantins.

Apesar da comprovada capacidade de melhorar o desempenho de suínos, o uso de antimicrobianos como promotores do crescimento vem sendo progressivamente restringido em diversos países. As novas regulamentações têm forçado a procura por alternativas ao uso de antibióticos e quimioterápicos como promotores do crescimento de suínos. Os extratos vegetais constituem uma dessas alternativas pesquisadas. Sendo assim, o objetivo do trabalho foi avaliar os efeitos de antimicrobianos e extratos vegetais sobre a digestibilidade aparente dos nutrientes, desempenho, morfometria dos órgãos, histologia do epitélio intestinal, microbiologia intestinal e frequência de diarréia de leitões recém-desmamados. Foram realizados três experimentos em blocos casualizados, nos quais foram testados, durante 35 dias, cinco tratamentos: controle - ração basal; antimicrobiano - basal com bacitracina de zinco, olaquindox e colistina (50 ppm de cada); extrato vegetal A, B e C - basal com 700, 1200 e 2100 ppm de extrato vegetal, respectivamente. O extrato vegetal foi constituído de quantidades iguais de óleo essencial de cravo, tomilho, orégano, eugenol e carvacrol. Foram utilizados 40 leitões em cada experimento, com idades iniciais e finais de, respectivamente, 21 e 56 dias. Foram alocados dois leitões (um macho castrado e uma fêmea) em cada baia (unidade experimental). No ensaio de digestibilidade (Experimento I) utilizou-se o método da coleta parcial de fezes, tendo o óxido crômico (Cr2O3) como marcador. Ao final do Experimento I, um animal de cada unidade experimental foi abatido para análise de morfometria dos órgãos e coleta de amostras do epitélio intestinal para análise histológica e microbiológica. Nos Experimentos I, II e III, foram medidas a frequência de diarréia e as variáveis de desempenho. A digestibilidade da matéria seca foi maior (P<0,05) para o tratamento com extratos vegetais em relação ao tratamento controle e com antimicrobianos. Durante os períodos de 1 a 14 e 1 a 35 dias de experimentação, o tratamento antimicrobiano apresentou melhores resultados (P<0,05) de peso vivo, consumo diário de ração e ganho diário de peso que os demais tratamentos. Dentre os níveis de extratos vegetais, o maior nível de inclusão foi o que proporcionou melhores resultados de desempenho. Na análise de morfometria dos órgãos, foram encontradas diferenças (P<0,05) entre os tratamentos apenas para o peso relativo do trato gastrintestinal total e do intestino delgado vazio, sendo que os melhores (menores) resultados foram obtidos para os animais suplementados com antimicrobianos. Para a histologia do epitélio intestinal, novamente os melhores resultados foram obtidos para o tratamento com antimicrobianos, tendo apresentado maior altura de vilosidade (P<0,05) e menor relação altura de vilosidade e profundidade de cripta do íleo que os tratamentos com extratos vegetais. Não foram encontradas diferenças significativas (P>0,05) para os resultados de microbiologia intestinal. A frequência de diarréia dos animais que receberam antimicrobianos foi inferior (P<0,05) àquela do tratamento controle ou extratos vegetais no período de 1 a 35 dias de experimentação, indicando eficácia dos antimicrobianos em controlar a diarréia. Os extratos vegetais apresentaram resultados intermediários entre o tratamento controle e com antimicrobianos para essa variável. / The use of antimicrobials as growth promoters of swine has been gradually restricted in many countries. The new regulations have forced the search for alternatives to the antibiotic use as growth promoters for swine. The herbal extracts are one of these alternatives. The purpose of this work was to evaluate the antimicrobial agents and herbal extracts as growth promoters, based on intestinal morphology, histology, microbiology, digestibility, fecal score, and on performance of weanling pigs. Three randomized complete block design experiments were carried out to compare five treatments: control - basal diet; antimicrobial - basal diet plus Zn bacitracin, olaquindox, and colistin (50 ppm of each); herbal extract A, B and C - basal diet plus 700 ppm, 1200 ppm and 2100 ppm of herbal extract, respectively. The herbal extract consisted of a mixture of equal amounts of essential oils of thyme, clove, oregano, eugenol and carvacrol. In each Experiment, forty 21-d-weaned pigs were allotted to 20 suspended pens, with two pigs (a castrated male and a female) per pen (experimental unit) and four replications per treatment. Digestibility assay (Experiment I) was conducted using chromic oxide (Cr2O3) as fecal marker. On 35th day of experimental period, an animal of each experimental unit was slaughtered for morphological analysis and samples of the intestine epithelium were collected for histological and microbiological analysis. Performance data and fecal score of pigs were collected from Experiments I, II and III. The herbal extracts increased (P<.05) the dry matter apparent digestibility of the diet compared to control and antimicrobial treatments. The antimicrobial agents improved (P<.05) body weight, feed intake and average daily gain of weanling pigs during 1 to 14 and 1 to 35 days of experimental period compared to control and herbal extract. Among all levels of herbal extract, higher levels showed better performance results. The antimicrobial treatment improved the relative weights of the intestinal tract and empty small intestine (P<.05) and improved ileum villus height and the ratio of ileum villus height:crypt depth of animals. There was no statistical difference (P>.05) in microbiological analysis. During 1 to 35 days of experimental period, incidence of diarrhoea of pigs fed antimicrobials was statisticaly lower (P<.05) than those fed control or herbal extract diet, suggesting the efficacy of antimicrobials in diarrhoea control. Pigs fed herbal extract showed intermediary results between antimicrobial and control diets for this variable.

O Brasil é o maior produtor de laranja doce do mundo, mas a história da citricultura brasileira é marcada por sucessivas perdas devido a pragas e doenças que atacam os pomares. Entre as doenças que afetam os pomares de citros, o huanglongbing (HLB) tem merecido destaque nos últimos anos. O HLB já é conhecido desde 1900 na China, mas no Brasil essa doença está presente desde 2004 e tem causado perdas significativas a citricultura. Essa doença é associada a três espécies de \"Candidatus Liberibacter\", mas no Brasil a espécie Candidatus Liberibacter asiaticus (CLas) é a mais comum. Devido à ausência de plantas de laranja doce resistentes a essa doença, a busca por plantas transgênicas que apresentem resistência a essa doença têm se intensificado nos últimos anos. Uma estratégia para projetar uma construção gênica visando a CLas é a utilização de promotores floema-específico, pois a CLas coloniza o floema das plantas de citros infectadas. Entretanto, para provar que uma sequência promotora funciona é preciso desafiar a construção gênica na presnça da CLas. Portanto, conduziu-se este trabalho com o objetivo de multiplicar plantas de Citrus sinensis Osbeck (L.) cv. \'Hamlin\' transgênicas contendo o gene uidA sob controle dos promotores floema-específicos Arabidopsis thaliana phloem protein 2 (AtPP2), Citrus phloem protein 2 (CsPP2) e Arabidopsis thaliana sucrose transporter 2 (AtSUC2), inocular com CLas por Diaphorina citri, avaliar a interdependência entre a expressão do transgene (gene uidA) e a concentração de CLas, para poder inferir sobre o controle da expressão dos promotores quando as plantas são inculadas com CLas. Para isso, cinco eventos de transformação de cada construção gênica, contendo apenas uma cópia do transgene foram selecionados, multiplicados e inoculados com CLas por Diaphorina citri, dezoito meses após a inoculação, o DNA e o RNA das plantas foram coletados. Foi realizada análise para verificar a concentração de CLas em todas as plantas inoculadas e a expressão do gene uidA foi realizada em uma linhagem transgênica de cada construção gênica. Com o auxílio da análise de coeficiente de correlação de Person, foi possível classificar qualitativamente a interdependência entre a concentração bacteriana e a expressão gênica. A frequência média de inoculação de CLas por Diaphorina citri foi de 30 %, demostrando que é possível incular CLas via Diaphorina citri. A análise de coeficiente de correlação de Person mostrou que nas construções com promotores AtPP2 e CsPP2 há baixa interdependência entre o controle da expressão gênica e a concentração de CLas. A construção sob controle do promotor AtSUC2 apresentou correlação forte e positiva, mostrando que quanto maior a concentração de CLas maior a expressão do transgene. / Brazil is the largest producer of sweet oranges in the world, however the Brazilian citrus history is marked by successive losses due to pests and diseases attacking orchards. Among the diseases affecting citrus groves, the huanglongbing (HLB) has been highlighted in recent years. The HLB is known in China since 1900, although in Brazil this disease has been present since 2004 and has caused significant losses to citrus industry. This disease is associated with three species of \"Candidatus Liberibacter\", however, in Brazil Candidatus Liberibacter asiaticus species (CLas) is the most common. Due to the absence of sweet orange plants resistant to this disease, the search for transgenic plants with resistance to this disease have intensified in recent years. One strategy to design a genetic construct targeting the CLas includes the use of phloem-specific promoters, because the CLas colonizes the phloem of infected citrus plants. On the other hand, to prove that a promoter sequence works it is necessary to challenge the genetic construct in the presence of CLas. Therefore, we conducted this study with the objectives of multiplying transgenic Citrus sinensis Osbeck (L.) cv. \'Hamlin\' bearing the uidA gene under the control of the phloem-specific promoters Arabidopsis thaliana phloem protein 2 (AtPP2), Citrus phloem protein 2 (CsPP2) and Arabidopsis thaliana sucrose transporter 2 (AtSUC2), inoculate CLas with Diaphorina citri, and evaluate the interdependence between the expression of the transgene (uidA gene) and the concentration of CLas, to infer the promoter expression when the plants are inoculated with CLas. Five events processing of each gene construct, containing only one copy of the transgene, and inoculated with CLas by Diaphorina citri. The DNA and RNA of plants were collected after eighteen months of inoculation. The concentration of CLas in the inoculated plants and the expression of the uidA gene were performed in each transgenic line of each gene construct, with the aid of the analysis of Person correlation coefficient. Thus it was possible to classify qualitatively the interdependence between bacterial concentration and gene expression. The average frequency of CLas inoculation by Diaphorina citri was 30%, demonstrating that it was possible to inoculate CLas via Diaphorina citri. Person correlation coefficient values suggested low interdependence between the control of gene expression and the concentration of CLas in constructions with promoters AtPP2 and CsPP2. The construction under AtSUC2 promoter control showed strong positive correlation, indicating that the higher the concentration of CLas the greater is the transgene expression.

Les rapides progrès technologiques en matière de techniques de biologie à grande échelle, comprenant notamment les microarrays, conduisent en 2006 au développement d’une nouvelle génération de puces à très haute résolution, capables de cibler à la fois tous les gènes du transcriptome humain, mais également tous les exons de ces gènes pris individuellement. L’avènement de cette puce, communément appelée puce exon, permit d’obtenir une mesure précise des changements transcriptomiques affectant les cellules cancéreuses, en offrant la possibilité de prendre en compte l’expression relative de différents exons d’un même gène.L’épissage alternatif et la transcription alternative sont les deux principaux mécanismes biologiques à l’origine de l’existence de plusieurs transcrits pour un même gène. Ces processus biologiques ont été mis en évidence depuis longtemps mais leur régulation dans les cellules normales ainsi que leurs dérégulations dans les cancers sont encore mal caractérisées de par la complexité des mécanismes impliqués. Par leur design, les puces exons permettent de mettre en évidence la présence de variations d’expression entre plusieurs transcrits potentiels d’un même gène, ouvrant ainsi la voie à une meilleure compréhension de ces processus biologiques.A partir d’un important jeu de données d’échantillons de cancers de la vessie dont le profil transcriptomique fut obtenu par puces exons, nous nous sommes intéressés à l’étude des changements d’épissage alternatif et à l’utilisation de promoteurs alternatifs dans les tumeurs de vessie. L’utilisation d’outils statistiques et mathématiques dédiés à l’analyse de ces puces nous a permis dans un premier temps d’identifier de nombreux gènes dont l’expression relative des différents transcrits est spécifiquement dérégulée dans les tumeurs de vessie. Ces transcrits constituent une nouvelle source pour l’identification de cibles thérapeutiques spécifiques des tumeurs. Nous avons pu montrer qu’avec une approche ciblée sur les changements d’expression relative de transcrits alternatifs d’un même gène, il était possible de constituer un panel de potentiels marqueurs tumoraux permettant le développement de nouveaux tests urinaires utiles à la détection des cancers de vessie et à la surveillance des patients.Par une analyse non supervisée des profils d’exons potentiellement dérégulés, nous avons pu observer une stratification des tumeurs similaire à celle observée par l’étude des profils géniques issus de puces classiques, confirmant alors l’existence d’un sous groupe de tumeurs de vessie présentant des caractéristiques transcriptomiques propres. Nous avons pu associer à ce sous-groupe de mauvais pronostic, une signature d’inclusion différentielle de certains exons. Cette signature impliquant 19 gènes permet d’identifier précisément ces tumeurs de manière très spécifique et constitue par conséquent un outil puissant utilisable en clinique.L’étude ciblée d’une voie de signalisation fréquemment dérégulée dans les cancers nous a permis de mettre en évidence une dérégulation globale de l’expression relative des transcrits alternatifs de gènes impliqués dans la prolifération cellulaire, et d’en identifier de probables régulateurs. Enfin, L’analyse des données de puces exons à la lumière des données de méthylation de l’ADN nous a permis d’identifier un mécanisme épigénétique régulant l’utilisation de promoteurs alternatifs dans un sous-groupe de tumeurs de vessie.L’ensemble des résultats obtenus par l’analyse de ces puces exons a par conséquent permis de caractériser à l’échelle du transcrit les dérégulations spécifiques des tumeurs de vessie, et d’en identifier certains mécanismes. Ces dérégulations permettent non seulement d’identifier spécifiquement plusieurs sous-groupe de tumeurs dont un de mauvais pronostic, mais offrent également de nouvelles possibilités quant-à la recherche de marqueurs urinaires pour la surveillance des patients. / The development of microarray technology in the late 1990’s served as an essential tool to comprehend the scope of transcriptomic deregulations occurring in cancer cells. Signals generated from the first generation of transcriptomic microarrays gave simultaneous measures of expression from a large number of genes, therefore enabling to identify candidate genes involved in cancer progression and putative therapeutic targets. In 2006, through a fast de- velopment of high-throughput technologies, the available large scale analysis tools became enriched with a new generation of high resolution microarrays measuring expression signals both at the gene-level and at the exon-level of each gene. The advent of this high-resolution microarray, commonly called exon array, provided the opportunity to get a more accurate meas- ure of transcriptomic changes affecting cancer cells by enabling to consider relative expression changes of the exons from a same gene.Alternative splicing and alternative transcription are the two main biological mechanisms accounting for the production of several transcripts from a same gene. Although these bio- logical processes have been known for a long time, their regulation in normal cells and their deregulation in cancer still remain challenging to well-characterize, mainly due to the complex- ity of the involved mechanisms. Through their design, exon arrays enable to identify variable expression patterns within several potential transcripts of a same gene, therefore bringing new insight into these biological processes.Based on a large dataset of bladder cancer samples that were profiled on exon arrays, we focused on the study of alternative splicing changes and alternative promoter usage in bladder tumours. Analysis of these exon arrays through the use of adapted statistical and mathemat- ical tools initially resulted in the identification of numerous genes showing differential relative expression patterns of their transcripts between cancer and normal samples. These transcripts represent a new opportunity to define tumour-specific therapeutic targets. We demonstrated that using an approach targeted on relative expression changes of transcripts from a same gene, it was possible to build up a panel of potential tumour-specific markers enabling the development of new urinary test to detect bladder cancer and monitor its evolution.Through an unsupervised analysis of putatively deregulated exon profiles, we observed that the partitioning of bladder tumours was similar to the classification resulting from the study of classical gene microarray expression profiles, consequently confirming the existence of a bladder subgroup with peculiar transcriptomic properties. For this subgroup of bad prognosis, we established a signature based on the differential alternative inclusion of several exons. This signature relates to 19 genes and enables to accurately identify tumours from this subgroup, therefore providing a powerful tool to be used in clinical practice.By studying a specific pathway often deregulated in cancer, we highlighted an overall dereg- ulation of the relative expression of alternative transcripts from genes involved in cell prolifer- ation, and identified potential actors involved in the underlying regulatory process. Eventually, the analysis of exon arrays in the light of DNA methylation array data enabled us to identify an epigenetic mechanism regulating the use of alternative promoters in a subgroup of bladder tumours.Together, the results obtained from exon array analysis consequently provided a character- ization at the transcript level of bladder tumour specific deregulations and brought insight into the underlying mechanisms. The highlighted deregulations not only allow to accurately identify two subgroups of tumours, of which one has a bad prognosis, but also offer new possibilities regarding the definition of urinary markers for patient monitoring.