Selon les nouvelles orientations agroécologiques qui s’imposent largement, il convient d’élaborer des systèmes d’élevage adaptés aux contraintes environnementales, efficients et pourvoyeurs de services écosystémiques bénéfiques pour l’environnement et la société. La question se pose singulièrement dans nos territoires antillais et ceci dans le cadre d’une demande pressante en produits carnés de qualité et à forte valeur patrimoniale comme l’est la viande caprine en Guadeloupe. Les petits ruminants, principalement élevés au pâturage, sont exposés aux infestations par les nématodes gastro-intestinaux (NGI) qui constituent une cause majeure de morbidité et de mortalité. Le déploiement de techniques adaptées et applicables sur le terrain s’avère nécessaire. Aussi des méthodes de gestion intégrée du parasitisme sont préconisées parmi lesquelles sont étudiées les stratégies d’alimentation des animaux. Il convient d’améliorer la capacité de l’animal hôte à tolérer les effets négatifs (résilience) ou à contrôler les infestations par les NGI (résistance) par la complémentation alimentaire. L’objectif de cette thèse était de définir des stratégies de complémentations des chevreaux en croissance, stade physiologique le plus touché par les NGI et dont les performances zootechniques conditionnent directement le revenu des producteurs (la production de viande).L’apport de la complémentation a été combinée à une série de recommandations de la gestion intégrée du parasitisme (voie génétique, méthode Famacha ®) et singulièrement à une stratégie de gestion du pâturage mixte avec des génisses. Ont été obtenus, un accroissement des résultats zootechniques (croissance et carcasse), de la note d’état corporel ainsi qu’une amélioration de la réponse physiologique (taux d’hématocrite). Une diminution du nombre de traitements anthelmintiques est observée aussi. Cet essai a abordé l’opérationnalité de la complémentation pour un éleveur. D’une façon générale, ce travail a ouvert aussi des questionnements scientifiques sur l’interaction nutrition*parasitisme avec un focus sur la nutrition azotée à déconnecter de l’alimentation énergétique. / New agroecological guidelines are needed around the world to develop livestock systems that are adapted to the environmental, efficient and environmentally and socially beneficial ecosystem services requirements. The question arises singularly in our Caribbean territories and this in the context of an urgent demand in meat products of quality and ofhigh patrimonial value as is the goat meat in Guadeloupe. Small ruminants, mainly grazed, are exposed to gastrointestinal nematode (NGI) infestations, which are a major cause of morbidity and mortality. The deployment of adapted and applicable techniques in the field is necessary. Therefore, methods of integrated management of parasitism are recommended among which are studied the strategies of feeding of the animals. The ability of the host animal to tolerate adverse effects (resilience) or to control infestations by NGI (resistance) should be enhanced by food supplementation. The objective of this thesis was to define supplementation strategies for growing kidneys, the physiological stage most affected by NGI and whose zootechnical performances directly affect the incarne of producers (meat production).Discussions focus on the development of targeted complementing strategies and attempt to answer questions: how to complement? (ln energy, nitrogen or both); When to complement? (Delay effects or effects during an established infestation). lt was also a question oftesting the life-size recommendations and on several variables (physio­pathological responses and zootechnical responses including carcass characteristics). In this sense this work has presented a certain originality. There was no statistically significant effect on carcass quality, however, in carcass­infected animals the carcasses were more degraded, especially with a low-protein diet. The complementation contribution was combined with a series of recommendations of integrated management of parasitism (genetic pathway, famacha method) and particularly a management strategy of mixed grazing with heifers. An increase in the zootechnical results (growth and carcass), body condition score and an improvement in physiological response, hematocrit) were obtained. A decrease in the number of anthelmintic treatments is also observed. This trial addressed the operationality of complementation for a breeder. In general, this work also opened up scientific questions about the interaction nutrition * parasitism with a focus on nitrogen nutrition to disconnect from the energy suooly

B. braunii is a green alga that has attracted attention as a potential renewable fuel source due to its high oil content and the archeological record of its unique contribution to oil and coal shales. Three extant chemotypes of B. braunii have been described, namely race A, race B, and race L, which accumulate alkadienes and alkatrienes, botryococcene and squalene and their methylated derivatives, and lycopadiene, respectively. The methylated triterpenes, particularly botryococcenes, produced by race B can be efficiently converted to high quality combustible fuels and other petrochemicals; however, botryococcene biosynthesis has remained enigmatic. It has been suggested that botryococcene biosynthesis could resemble that of squalene, arising from an initial condensation of two molecules of farnesyl diphosphate (FPP) to form pre-squalene diphosphate (PSPP), which then undergoes a reductive rearrangement to form squalene, or in an alternative reductive rearrangement, botryococcene. Based on the proposed similarities, we predicted that a botryococcene synthase would resemble squalene synthase and hence, isolated squalene synthase-like genes from B. braunii race B. While B. braunii does harbor at least one typical squalene synthase, none of the other three squalene synthase-like (SSL) genes encode for botryococcene biosynthesis directly. SSL-1 catalyzes the biosynthesis of PSPP and SSL-2 the biosynthesis of bisfarnesyl ether and to a lesser extent squalene, while SSL-3 does not appear able to directly utilize FPP as a substrate. However, when SSL-1 is combined with either SSL-2 or SSL-3, in vivo and in vitro, robust squalene or botryococcene biosynthesis was observed, respectively. These findings were unexpected because squalene synthase, an ancient and likely progenitor to the other Botryococcus triterpene synthases, catalyzes a two-step reaction within a single enzyme unit without intermediate release, yet in B. braunii, these activities appear to have separated and evolved inter-dependently for specialized triterpene production. Expression of various configurations of the SSL genes in TN-7 yeast demonstrates that botryococcene can be efficiently produced in a heterologous host. Additionally, three triterpene methyltransferase (TMTs) were isolated which efficiently catalyze the transfer of a methyl group from S-adenosyl methionine (SAM) to either squalene (TMT-1 and TMT-2) or botryococcene (TMT-3) in vivo and in vitro. Co-expression of the various TMT genes with either squalene synthase or botryococcene synthase in TN-7 yeast resulted in the accumulation of C31 and C32 methyl derivatives of squalene or botryococcene, demonstrating their potential for heterologous production. The methylation sites were determined by NMR spectroscopy to be identical to C31 and C32 methyl-derivatives of squalene or botryococcene observed in B. braunii race B. Expression studies of various heterologous squalene synthase genes in S. cerevisiae corroborated an earlier but surprising observation reported in the literature. While the squalene synthase gene of S. cerevisiae was able to complement an erg9 (squalene synthase) knockout in yeast, squalene synthase genes from plants and animals were not. Chemical profiles revealed that squalene accumulated to significant levels in yeast expressing the squalene synthase of plant, animal, or S. cerevisiae. This suggested that it was not the ability of these heterologous synthase enzymes to produce squalene, but their inability to feed squalene into the native sterol biosynthetic pathway that prevented them from restoring normal ergosterol biosynthesis in S. cerevisiae. By examining the ability of chimera squalene synthase enzymes to complement the erg9 mutation, a discrete sequence of amino acids near the C-terminus of the enzyme was identified which is necessary and sufficient for allowing any squalene synthase to restore normal sterol metabolism.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

<p>The DNA of a cell operates as its blueprint, providing coded information for the production of the RNA and proteins that allow the cell to function. Cells can face a myriad of insults to their genomic integrity during their lifetimes, from simple errors during growth and division to reactive oxygen species to chemotherapeutic reagents. To deal with these mutagenic insults and avoid passing them on to progeny, cells are equipped with multiple defenses. Checkpoints can sense problems and halt a cell’s progression through the cell cycle in order to allow repairs. More drastically, cells can also prevent passing on mutations to progeny by triggering apoptosis, or programmed cell death. This work will present two separate discoveries regarding the regulation of DNA damage-induced apoptosis and the regulation of the spindle checkpoint.</p><p> The protease caspase-2 has previously been shown to be an important regulator of DNA damage-induced apoptosis. In unstressed cells caspase-2 is present as an inactive monomer, but upon sensing a stress caspase-2 dimerizes and becomes catalytically active. The mechanisms that regulate this dimerization are poorly understood. The first research chapter details our development of a novel method to study dimerized caspase-2, which in turn identified TRAF2 as a direct activator of caspase-2. Specifically, we utilized the Bimolecular Fluorescence Complementation technique, wherein complementary halves of the Venus fluorophore are fused to caspase-2: when caspase-2 dimerizes, the non-fluorescent halves fold into a functional Venus fluorophore. We combined this technique with a Venus-specific immunoprecipitation that allowed the purification of caspase-2 dimers. Characterization of the caspase-2 dimer interactome by MS/MS identified several members of the TNF Receptor Associated Factor (TRAF) family, specifically TRAF1, 2, and 3. Knockdown studies revealed that TRAF2 plays a primary role in promoting caspase-2 dimerization and downstream apoptosis in response to DNA damage. Identification of a TRAF Interacting Motif (TIM) on caspase-2 indicates that TRAF2 directly acts on caspase-2 to induce its activation. TRAF2 is known to act as an E3 ubiquitin ligase as well as a scaffold for other E3 ubiquitin ligases. Indeed, we identified three lysine residues in the caspase-2 prodomain (K15, K152, and K153) important for its ubiquitination and complex formation. Together these results revealed a novel role for TRAF2 as a direct activator of caspase-2 apoptosis triggered by DNA damage.</p><p> During mitosis, when the cell prepares to divide, great care is taken to ensure that the chromosomes are properly segregated between the two daughter cells by the mitotic spindle. This is primarily accomplished through the spindle checkpoint, which becomes activated when the mitotic spindle is not properly attached to each chromosome’s kinetochore. When activated, the primary effector of the spindle checkpoint, the mitotic checkpoint complex (MCC), inhibits the anaphase-promoting complex (APC/C) by binding to the APC/C co-activator, CDC20. This prevents the APC/C from targeting critical pro-mitotic proteins, like cyclin B and securin, to promote mitotic exit. Although the function of the MCC is well understood, its regulation is not, especially in regard to protein phosphatases To investigate this, we activated the spindle checkpoint with microtubule inhibitors and then treated with a variety of phosphatase inhibitors, examining the effect on the MCC and APC/C. We found that two separate inhibitors, calyculin A and okadaic acid (1uM), were able to promote the dissociation of the MCC. This led to the activation of the APC/C, but the cells remained in mitosis as evidenced by high levels of Cdk1 activity and chromosome condensation. This is the first time that phosphatases have been shown to be essential to maintaining the MCC and an active spindle checkpoint.</p> / Dissertation

Phosphoglucosamine mutase (GlmM) is an enzyme of bacterial cell wall biosynthesis. The main aim of this thesis was to find out, whether gene glmM is essential for viability of Streptococcus pneumoniae. Therefore, we prepared merodiploid strain containing two copies of glmM; the genomic gene and ectopic copy under control of zinc inducible promoter. Subsequently, depletion strain was prepared by deletion of genomic copy of glmM. This strain was further used for analysis of viability and phenotype features in the medium containing various concentrations of zinc ions, an inducer of ectopic glmM expression. We found out, that the viability of this strain was strictly dependent on the concentration of inducer and further, that depletion of GlmM resulted in remarkable morphological defects. The rescue of mutant strain was observed after addition of inducer up to the level of the control sample. These results have provided the evidence of glmM essentiality for S. pneumoniae viability. Furthermore, we analyzed, whether phosphorylation of key amino acid residues, S99 and S101, is essential for GlmM functionality. Four different strains were prepared by means of site-directed mutagenesis expressing glmM with substitutions of key serine residues for alanine or glutamic acid. Since deletion of chromosomal locus in...

Este trabalho tem por objetivo identificar as diferenças e semelhanças do intercâmbio comercial de produtos e serviços entre Peru e Brasil a través da evolução das relações bilaterais entre os dois países a partir do ano 2000. Com este estudo se procura evidenciar que uma convivência harmoniosa e uma trajetória de crescimento econômico dinâmico para o Brasil, dependerá da adoção de estratégias bilaterais de comércio, para assim melhor liderar os países integrantes do Mercosul. Houve necessidade, então, de dividir a pesquisa em três frentes: Primeiro, o levantamento de diferentes conceitos teóricos para melhor entendimento do significado de Complementaridade Econômica/Integração Econômica. Segundo, os Perfis Econômicos de Peru e Brasil a partir do ano 2000. Terceiro, As Relações Bilaterais Comerciais entre Peru e Brasil a partir do ano 2000. Assim, constatamos que falta eliminar divergências nas estatísticas de comércio bilateral de ambos países e que ainda não há harmonização na qualificação dos produtos. A pesquisa compreendeu o levantamento bibliográfico e bibliográfico-digital referente a cada um dos capítulos projetados. / This research has as objective identify the differences between e common points of the commercial exchange of goods and services between Peru an d Brazil take into account the evolution of the bilateral relations since 2000. This research aims underline that a harmonic relation and an background of dynamic economic growth, as for Brazil, will depend of developing bilateral strategies of trade. That strategy will allow improve the Brazilian leadership in relation to the MERCOSULs countries. There were necessity of organizing the research in three parts: first, discussion of the basic theoretical concepts to improve the understanding of economic complementation and regional integration. Second, the economic profile from Peru and Brazil since 2000. Third, the commercial and bilateral relations between Peru and Brazil since 2000. Thus, the research conclude that there are divergences in statistics of both of countries , and that there is not still harmony in the qualification of trade products. This research embraces a bibliographical framework and bibliographical-digital framework.

Este trabalho tem por objetivo identificar as diferenças e semelhanças do intercâmbio comercial de produtos e serviços entre Peru e Brasil a través da evolução das relações bilaterais entre os dois países a partir do ano 2000. Com este estudo se procura evidenciar que uma convivência harmoniosa e uma trajetória de crescimento econômico dinâmico para o Brasil, dependerá da adoção de estratégias bilaterais de comércio, para assim melhor liderar os países integrantes do Mercosul. Houve necessidade, então, de dividir a pesquisa em três frentes: Primeiro, o levantamento de diferentes conceitos teóricos para melhor entendimento do significado de Complementaridade Econômica/Integração Econômica. Segundo, os Perfis Econômicos de Peru e Brasil a partir do ano 2000. Terceiro, As Relações Bilaterais Comerciais entre Peru e Brasil a partir do ano 2000. Assim, constatamos que falta eliminar divergências nas estatísticas de comércio bilateral de ambos países e que ainda não há harmonização na qualificação dos produtos. A pesquisa compreendeu o levantamento bibliográfico e bibliográfico-digital referente a cada um dos capítulos projetados. / This research has as objective identify the differences between e common points of the commercial exchange of goods and services between Peru an d Brazil take into account the evolution of the bilateral relations since 2000. This research aims underline that a harmonic relation and an background of dynamic economic growth, as for Brazil, will depend of developing bilateral strategies of trade. That strategy will allow improve the Brazilian leadership in relation to the MERCOSULs countries. There were necessity of organizing the research in three parts: first, discussion of the basic theoretical concepts to improve the understanding of economic complementation and regional integration. Second, the economic profile from Peru and Brazil since 2000. Third, the commercial and bilateral relations between Peru and Brazil since 2000. Thus, the research conclude that there are divergences in statistics of both of countries , and that there is not still harmony in the qualification of trade products. This research embraces a bibliographical framework and bibliographical-digital framework.

Cette étude vise à fournir une description détaillée de l’évidentialité en anglais dans une approche contrastive avec le tibétain. Elle repose sur un corpus spécialement recueilli au Tibet et en Angleterre (TSC et CSC/LAC, 2010-2012, 10 h.). Le tibétain possède un système évidentiel complexe et grammaticalisé dont la description peut fournir une grille d’analyse préliminaire pour notre étude de l’évidentialité en anglais. Des exemples authentiques et des données quantitatives issus du corpus nous permettent d’illustrer et de compléter les descriptions du groupe verbal tibétain dans plusieurs travaux pionniers antérieurs à la présente recherche (Tournadre & Sangda Dorje 1998) afin de poser les bases de la sémantique évidentielle. Les marqueurs évidentiels qui émergent dans les parties tibétaine et anglaise du corpus sont examinés afin de déterminer les paramètres qui motivent leur utilisation. Les marqueurs tibétains sont principalement grammaticaux et intégrés à des paradigmes syntaxiques : copules, suffixes verbaux et enclitiques. Les marqueurs évidentiels anglais sont lexicaux ou semi-grammaticaux : verbes de perception, verbes de cognition, verbes de discours, modaux, adverbes, conjoints, parenthétiques et marqueurs de discours (Nuyts 2001a, Cappelli 2007, Sanders & Sweetser 2009, Mortensen 2010, Whitt 2010, Gisborne 2010, Miller 2008, Boulonnais 2010, Gurajek 2010, Kaltenböck et coll. 2011, Heine 2013). Cette description de l’évidentialité en tibétain et en anglais nous permet d’analyser les conséquences d’un rendu grammatical ou lexical de cette notion (Talmy 2000, Bybee et coll. 1994, Nuyts 2001a, Boye & Harder 2009). Des analyses quantitatives et qualitatives du corpus contrastif et sur large corpus illustrent les différences de complexité, d'optionalité, de fréquence, de restriction sémantique, de prise en charge, de statut informatif, et de stratégie de discours dans les deux systèmes.Enfin, nous réévaluons la dichotomie, souvent considérée comme acquise, entre évidentialité grammaticale et lexicale (Aikhenvald 2004). Nous avançons que les marqueurs évidentiels des deux langues se positionnent à différents endroits sur un continuum multidimensionnel lexique-grammaire. Cette étude ne remet pas en question que le système évidentiel tibétain est plus grammaticalisé que le système anglais, mais démontre que ce dernier présente tous les signes d’une grammaticalisation partielle. Nous concluons ainsi que l’évidentialité est une notion pertinente et nécessaire pour une description linguistique complète de l’anglais. / This study aims to give a detailed description of evidentiality in English in contrast with Tibetan. It is based on a specialised corpus collected in Tibet and in England (TSC and CSC/LAC, 2010-2012, 10 h.).Tibetan has a complex and grammaticalised evidential system, and its description can provide a preliminary analytical grid for a semantic assessment of English evidentiality. Athentic examples and quantitative data from the corpus illustrate and supplement the analyses of the Tibetan verb phrase from previous research (Tournadre & Sangda Dorje 1998), in order to lay the foundation of the semantics of evidentiality. The evidential markers that emerge in the Tibetan and English sections of the corpus are examined so as to determine the parameters that motivate their usage. Tibetan evidentials are mainly grammatical and paradigmatised: copulas, verb suffixes and enclitics. English evidentials are either lexical or semi-grammatical: perception verbs, cognition verbs, speech verbs, modals, adverbs, conjuncts, parentheticals and discourse markers (Nuyts 2001a, Cappelli 2007, Sanders & Sweetser 2009, Mortensen 2010, Whitt 2010, Gisborne 2010, Miller 2008, Boulonnais 2010, Gurajek 2010, Kaltenböck et al. 2011, Heine 2013).This survey of Tibetan and English evidentiality provides precise data for the analysis of the consequences of a grammatical or a lexical rendering of this notion (Talmy 2000, Bybee et al. 1994, Nuyts 2001a, Boye & Harder 2009). Qualitative and quantitative evidence illustrates the differences in complexity, optionality, frequency, semantic restriction, speaker commitment, informative status and discourse strategy in the two systems. Finally, this study reassesses the assumed dichotomy between grammatical and lexical evidentiality (Aikhenvald 2004), arguing that evidentials in both Tibetan and English inhabit a lexicon-grammar multidimensional continuum, merely in different positions. This study does not question that the Tibetan evidential system is more grammaticalised than the English one, but it shows that the latter presents all the signs of partial grammaticalisation. This reassessment leads to the conclusion that evidentiality is a relevant and necessary notion for a thorough linguistic description of English.

<p>This thesis is a survey of the field of languages over infinite sequences. There is active research going on in this field, during the last year several new results where published. </p><p>We investigate the language containment problem for infinite sequences, with focus on complementation of Büchi automata. Our main focus is on the approach with alternating automata by Kupferman&Vardi. The language containment problem has been proved to be in EXPSPACE. We identify some cases when we can avoid the exponential blow-up by taking advantage of properties of the input automaton. </p><p>Some of the algorithms we explain are also implemented in a Sicstus Prolog library.</p>

E. coli SecA is an essential component for protein translocaiton across membrane. SecA can be deleted from its N- and/or C-terminal ends without losing complementation activity. In this study, we determined the dispensity of both ends of SecA molecule. The minimal length at the SecA C-terminus is dependent on the length of the N-terminal region. SecA10-826 and SecA22-829 are the two minimal length SecAs. One more amino acid deleted at the C-terminal end completely abolished their complementation activity. A hydrophobic amino acid is required at the 826th amino acid in the minimal-length SecAs. Both SecA22-828 and SecA22-829 could form a dimer, and have decreased ATPase and protein translocation activities. The active truncated SecA mutants tended to have more soluble form than membrane-bound form, but were stably embedded in membrane. In contrast, the inactive truncated SecA mutants tended to have more membrane-bound form, but were not stable in membrane. Thus, the loss of complementation is not related to dimerization, ATPase and translocation activity but to certain extent related to their biased subcelluar localization and conformation in membrane. Isolated membranes of E coli strains were solubilized and fractionated by sucrose gradient fractionation. These membranes fractions were depleted of SecY and YidC, but contained SecD, SecF and GroEL. Proteoliposomes reconstituted from these fractionated membrane proteins were active in pOmpA translocation which required SecA and ATP. Membrane fractions from strain CK1801 in which the unc gene is deleted were reconstituted into liposomes and also showed translocation activities. Moreover, proteoliposomes reconstituted with Bacteriorodopsin alone were not active in translocation, while proteoliposomes reconstituted with Bacteriorodopsin and CK1801 membrane fractions showed elevated translocation efficiency. These data suggested that proton motive force is not obligatory for, but stimulatory to translocation of pOmA. Purified GroEL was reconstituted into lipsomes and the reconstituted proteoliposomes were active in pOmpA translocation although at lower efficiency. This translocation also required SecA and ATP. These results together suggested that translocation of pOmpA is active in the absence of SecY and YidC. In the absence of SecYEG, translocation of pOmpA requires SecA and ATP. GroEL, SecD and SecF may participate in the SecY-independent translocation.