Les stress abiotiques sont la cause principale des pertes de rendement agricole dans le monde. Aujourd'hui, le développement d'espèces capables de résister à ces stress est d'une importance majeure, en particulier dans le contexte de la croissance démographique actuelle et du changement climatique mondial. La phytohormone acide abscissique (ABA) contrôle divers processus cellulaires et induit un signal de protection des plantes contre les stress abiotiques. Parmi les différents évènements moléculaires impliqués dans la voie de signalisation de l'ABA, les cascades de signalisation des mitogen activated protein kinase (MAPK) jouent un rôle important dans la transmission du signal. Cependant, seulement un nombre réduit de MAPK ont été identifiées et caractérisées jusqu'à maintenant.J'ai isolé 2 proches homologues MEKK-like MAPKKKs d'Arabidopsis, MAPKKK17 et MAPKKK18, dont le niveau d'expression étaient fortement induit en réponse à l'ABA et aux stress abiotiques. Chez les mutants insensibles à l'ABA, pyr1/pyl1/pyl2/pyl4 et hab1G246D, l'expression ABA- et sel-dépendant de ces deux gènes était fortement réduite, indiquant que ces 2 kinases agissent en aval du complexe de signalisation de l'ABA. L'utilisation de plantes transgéniques exprimant, sous le contrôle de son propre promoteur, le gène MAPKKK18 fusionné à une étiquette PC2 ou YFP a permis de montrer par western blot que la protéine s'accumulait suite à un traitement à l'ABA et non pas en réponse au stress abiotiques. Ces données montrent que l'ABA est le régulateur majeur de la fonction de MAPKKK18.Suite à une approche de yeast-2-hybrid, j'ai pu identifier MKK3 comme la seule MAPKK interagissant avec MAPKKK17 and MAPKKK18. Ces résultats ont pu être confirmés via la technique de BiFC. Dans des protoplastes de mésophylle, il apparait que MAPKKK17 et MAPKKK18 activent MKK3, indiquant que ces deux gènes codent pour des kinases fonctionnelles. Afin d'apporter des preuves génétiques, j'ai isolé les T-DNA knockout mutants de ces 3 gènes. Des analyses de germination révèlent que mkk3-1 est hypersensible à l'ABA, au sel et au mannitol tandis que la lignée de surexpression Gain-de-fonction présente un phénotype opposé. Cependant, les doubles mutants mapkkk17/18 ne présentent pas de phénotype de germination. D'autres analyses ont pu montrer que mkk3-1 est sensible à la sécheresse et au stress salin tandis que les lignées surexpresseures sont plus tolérantes. Le double mutant mapkkk17/18 est quant à lui seulement sensible au NaCl. Pris dans leur ensemble, ces résultats indiquent que MAPKKK17/MAPKKK18 et MKK3 forment un complexe régulant la réponse des plantes aux stress abiotiques selon une voie dépendantes de l'ABA. / Abiotic stresses are the principal cause of crop failure worldwide. Developing crop plants better able to withstand these stresses has assumed great importance especially in the context of current population growth and global climatic change. The phytohormone abscisic acid (ABA) regulates diverse cellular processes and transduces signals to protect plants from abiotic stresses. Among the molecular elements working in ABA signaling, the mitogen activated protein kinase (MAPK) cascades play important roles in regulating the signaling network. To date, however, only a handful of MAPKs have been identified and characterized in ABA signaling. I isolated 2 closely related Arabidopsis MEKK-like MAPKKKs, MAPKKK17 and MAPKKK18, whose transcript expressions were highly induced by ABA and abiotic stresses. In 2 ABA insensitive mutants, pyr1/pyl1/pyl2/pyl4 and hab1G246D, the ABA- and NaCl-dependent expression of MAPKKK17 and MAPKKK18 was strongly reduced, indicating that these 2 kinases act downstream of the core ABA signaling complex. Western blot analysis of transgenic plants that expressed either a PC2 or YFP tagged MAPKKK18 under endogenous promoter revealed that MAPKKK18 protein strongly accumulated in response to ABA treatment but not in response to other abiotic stresses. This data indicated that ABA is the major regulator of MAPKKK18 protein function.Using yeast-2-hybrid approach, I identified MKK3 as the downstream MAPKK interactor of MAPKKK17 and MAPKKK18, and confirmed these interactions via BiFC assays. In mesophyll protoplasts, MAPKKK17 and MAPKKK18 activated MKK3, indicating that these 2 genes encode functional kinases. To provide genetic evidence of their functions, I isolated T-DNA knockout mutants of these genes. Germination assays reveal that mkk3-1 mutant was hypersensitive to ABA, NaCl and Mannitol stress whereas the over-expression line was resistant. The double homozygous mutant of mapkkk17/18 was not affected in germination. Further analysis revealed that mkk3-1 seedlings were sensitive to NaCl and terminal drought whereas the over-expression lines were resistant. The mapkkk17/18 seedlings were susceptible to NaCl but not terminal drought. Taken together, these results suggest that MAPKKK17/MAPKKK18 and MKK3 form complexes to regulate plant responses to abiotic stress in an ABA-dependent manner.

Texte remanié de: Th. doct--Hist.--Tours--Université François-Rabelais, 1999. / CDL = Cahiers du livre et du disque.

Th. doct.-ing.--Électrochim., électrochim. anal.--Grenoble--I.N.P., 1980. N°: DI 164.

Th.--Sci.--Bordeaux 1, 1979. N°: 632.

Réduire le sodium dans les aliments transformés est une recommandation de Santé Canada. Or, le NaCl a un effet barrière reconnu sur la croissance des microorganismes. Des souches de L. monocytogenes et S. aureus ont été génotypées et étudiées selon leur tolérance au NaCl. Leur cinétique de croissance a été étudiée dans des caillés modèles Camembert soumis à différentes réductions en NaCl ou substitutions partielles par du KCl. La croissance de L. monocytogenes était légèrement supérieure à la surface de caillés réduits de 30 % de NaCl alors qu’au centre, l’utilisation du KCl permettait une diminution de sa croissance. Les conditions expérimentées ont permis la survie de S. aureus dans tous les caillés. Dans chacun des cas, il y a eu croissance inacceptable des pathogènes du point de vue de l’innocuité alimentaire : le risque relié à leur croissance dans un Camembert est donc peu influencé par les conditions salines.

In recent years, leaders in school divisions across the nation have begun to implement social-emotional learning (SEL) curricula and programs explicitly within the academic day (DePaoli et al., 2017; Graczyk et al., 2013; Oberle et al., 2019). The purpose of this study was to examine teachers' perceptions of their role, as well as the role of school leadership, in the implementation and sustainability of an SEL curriculum. To conduct the study, all elementary teachers in one school division, approximately 220 teachers, were invited to participate by completing a survey regarding their beliefs and perceptions of implementation. Respondents supplied data for the study by providing demographic information, responding to four open-ended questions, and answering 42 questions by indicating their perception on a 5-point scale. The survey received a 27% response rate. The collected data were analyzed using statistics of responses to generate response category means, compile the response rate of data for each question, and code emerging themes to inform findings. Findings indicated the teachers felt it was the responsibility of all stakeholders to teach and model SEL for students. Most respondents, 85%, highly agreed with the belief that SEL practices promoted academic success by selecting almost always or always on the scaled response. Findings also indicated the teachers felt their building leadership did nothing to support SEL implementation, and further stipulated that more time and training were necessary to implement SEL successfully. The findings led to three implications for school leadership. First, teachers should partner with all other staff members and adults in the learning community to model and deliver SEL instruction. Second, data analysis revealed school leadership should identify one SEL curriculum for the school to ensure consistency in training, monitoring, and implementation. Finally, school leaders should dedicate time in the school day for explicit SEL instruction. / Doctor of Education / In recent years, leaders in school divisions across the nation have begun to implement social-emotional learning (SEL) curricula and programs explicitly within the academic day (DePaoli et al., 2017; Graczyk et al., 2013; Oberle et al., 2019). The purpose of this study was to examine teachers' perceptions of their role, as well as the role of school leadership, in the implementation and sustainability of an SEL curriculum. To conduct the study, all elementary teachers in one school division, approximately 220 teachers, were invited to participate by completing a survey regarding their beliefs and perceptions of implementation. Respondents supplied data for the study by providing demographic information, responding to four open-ended questions, and answering 42 questions by indicating their perception on a 5-point scale. The survey received a 27% response rate. The collected data were analyzed using statistics of responses to generate response category means, compile the response rate of data for each question, and code emerging themes to inform findings. Findings indicated the teachers felt it was the responsibility of all stakeholders to teach and model SEL for students. Most respondents, 85%, highly agreed with the belief that SEL practices promoted academic success by selecting almost always or always on the scaled response. Findings also indicated the teachers felt their building leadership did nothing to support SEL implementation, and further stipulated that more time and training were necessary to implement SEL successfully. The findings led to three implications for school leadership. First, teachers should partner with all other staff members and adults in the learning community to model and deliver SEL instruction. Second, data analysis revealed school leadership should identify one SEL curriculum for the school to ensure consistency in training, monitoring, and implementation. Finally, school leaders should dedicate time in the school day for explicit SEL instruction.

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

Pays meurtri par les premières guerres de Religion, le Cotentin est partagé entre la nécessité de panser ses plaies et celle d'en finir avec le péril huguenot. Loin de tout et enclin à la panique, le pays s'imagine menacé par une nouvelle invasion anglaise et l'érection d'une république protestante à Carentan. Éreintée par les guerres, privée très vite de ses chefs, la mobilisation de la noblesse locale doit composer avec ces officiers de bailliage et ce bas-clergé, qui ont leurs entrées à Paris, cultivent la rancune à l'égard de la Couronne, et considèrent que l'ancienne aristocratie n'est plus à la hauteur des enjeux.Ce travail prosopographique s'attache à lever le voile sur les composantes populaires de la Ligue rurale. Petits curés du Val de Saire avec hallebardes, chanoines coutançais portant arquebuses, seigneurs pillards, pirates et naufrageurs, contrebandiers et fermiers d'impôts, sergents véreux, potiers-défricheurs et gentilshommes-verriers de la Forêt de Brix, marchands de drap, foulons et teinturiers de Valognes, soit près d'un millier de fauteurs d'émeutes, composant une faune méconnue, picaresque et souvent interlope dont le dénominateur commun ne se réduit pas à l'anglophobie et l'anti-protestantisme primaires. Mais au lieu de se contenter d'une prosopographie passive, cette recherche se fait histoire politique, persuadée qu'au plus bas de l'échelle sociale, il y a aussi une opinion. dans une presqu'île où rien n'est plus compliqué que de prendre position publiquement et de s'entretuer entre gens de connaissance. Quitte à oublier le passé ou le travestir. / Harmed by the first Wars of Religion, the Cotentin region is torn between the need to mend its wounds and the need to put an end to the huguenot threat. Far away from everything and prone to panic, the region believes that it is threatened by a new english invasion or even worse, by the erection of a Protestant Republic in Carentan. However, the nobility is not leading the fight: exhausted by wars, quickly deprived from its leaders, it must deal with a small circle of bailiffs and lower clergymen with their own contacts in Paris, a small world which nurtures a rancor against the Crown and thinks that the aristocracy will not measure up to the issues at stake.This work focuses on the popular components of the rural League. Priests wielding halberds, canons carrying arquebuses, robber lords, pirates and shipwrecks looters, smugglers and farmer-generals taxing salt and beverages, corrupt sergeants, woodcutter-potters and glassmakers from the Brix forest, drapers, fullers and dyers, that make up to a thousand leaders and troublemakers, part of a an unknown, picaresque and often suspicious fauna whose common denominator is not reduced to primary anglophobia and anti-protestantism.This research is also a political story, convinced that at the bottom of the social scale, there is an opinion, even in Normandy. Hence the necessity to find new documents and confront the individual to the group, his words to his actions, his present to his past, in a peninsula where nothing is more complicated than taking a public stance and killing each other among acquaintances, Then forget about it or lie.