Chez les végétaux, peu de canaux ioniques sont identifiés moléculairement. Nos travaux, par l’apport de preuves fonctionnelles, mettent en évidence les propriétés électrophysiologiques d’une protéine de la membrane mitochondriale externe (MOM) de Phaseolus coccineus, VDAC32. Nous montrons que cette protéine forme un canal partageant plusieurs caractéristiques électrophysiologiques typiques des canaux anioniques voltages dépendants (VDACs) (cinétique d'ouverture et de fermeture, sensibilité au voltage, conductance relativement grande, courbe de voltage dépendance en forme de cloche). <p>Nous avons constaté que la concentration saline avait un effet sur la voltage-dépendance du canal. En effet, le VDAC devient insensible à la différence de potentiel appliquée lorsqu'il est reconstitué dans des concentrations physiologiques en sel. Nombreuses sont les expériences réalisées dans des conditions non physiologiques (1 M KCl), mais nous montrons dans ce travail que le canal ne se comporte pas de la même manière en conditions physiologiques (0,1 M KCl).<p>La première partie de notre travail a été consacrée à l’étude de l’effet du cholestérol et deux phytostérols les plus abondants (sitostérol et stigmastérol) sur la voltage-dépendance du VDAC. Dans ce chapitre, nous avons montré l’effet des stérols sur la fonction des canaux ioniques au niveau moléculaire. Le rôle des stérols sur la sélectivité et la voltage-dépendance du VDAC a été mis en évidence. L’étude des phytostérols a permis de comprendre comment les propriétés du VDAC peuvent être modulées avec le type de stérol et son abondance dans la membrane. De même, la réversibilité de l’effet des phytostérols sur le VDAC en présence de la Méthyle-β-cyclodextrine a été prouvée. La conductance unitaire n’était pas affectée par l’addition des stérols.<p>Le deuxième chapitre de cette thèse a été consacré à l’étude des deux principaux phospholipides membranaires ;la phosphatidylcholine (PC) et phosphatidyl-éthalamine (PE). Il a été montré qu’à des concentrations salines similaires à celles trouvées in vivo, la voltage-dépendance du VDAC est inhibée en présence de membrane formée de PC mais pas en présence de membrane formée de PE et/ou PE méthylé une fois et deux fois. De même, la voltage-dépendance est restaurée suite à l’ajout de 2% de phytostérol ou de 2% de PE ou lorsque le degré de méthylation de la choline diminue. L’effet des stérols sur la voltage-dépendance est réversible. Nous avons montré que la sélectivité aux anions augment lorsque le degré de méthylation de la choline diminue tandis que la conductance unitaire du canal est invariable.<p>Nos résultats indiquent que l’interaction lipide-protéine est essentielle pour la régulation de l’activité du canal VDAC. La nature de la tête polaire des lipides est déterminante pour cette régulation ce qui suggère qu’elle s’effectue au niveau de l’interface membrane-solution. <p>La suite de nos travaux nous a conduit à l’étude de l’effet du cation monovalent, divalent et trivalent sur le VDAC. Nous avons montré que la voltage-dépendance est perdue dans des concentrations faibles en KCl (100 mM) et que cette dernière est restaurée en présence de 800 mmolale en KCl ou 100 mM de calcium ou 30 mM de lanthane. Ces résultats suggèrent que la restauration de la voltage-dépendance à des faibles concentrations en sel (100 mmolale) impliquerait un effet électrostatique/In plants, only some ion channels are identified molecularly. By providing functional evidence, our work highlights electrophysiological properties of the outer mitochondrial membrane (MOM) protein of Phaseolus coccineus, VDAC32. We show that this protein forms a channel sharing several typical electrophysiological characteristics of voltages dependent anion channels (VDACs) (gating kinetics, voltage sensitivity, relatively large conductance, voltage dependence curve bell-shaped).<p>We found that the salt concentration had an effect on the voltage-dependence of channel. Indeed, VDAC becomes insensitive to the applied potential difference when it was reconstituted in physiological salt concentrations. The greater part of the experiments were performed under non-physiological conditions (1 M KCl), but we show in our work that the channel does not have the same behavior under physiological conditions (0.1 M KCl).<p>The first part of our work has been devoted to the study of the effect of cholesterol and the two most abundant phytosterols (sitosterol and stigmasterol) on the VDAC voltage dependence. In this chapter, we have shown the effect of sterols on ion channel function at the molecular level. The role of sterols on the selectivity and the voltage-dependence of VDAC was highlighted. The study of phytosterols helped us to understand how the properties of VDAC can be modulated with the type of sterol and its abundance in the membrane. Similarly, the reversibility of the effect of phytosterols on the VDAC in the presence of Methyl-β-cyclodextrin has been proven. The unit conductance was not affected by the addition of sterols.<p>The second chapter of this thesis was devoted to the study of the two major membrane phospholipids, phosphatidylcholine (PC) and phosphatidylethalamine (PE). It has been shown that in similar salt concentrations to those found in vivo, the VDAC voltage-dependence is inhibited in the presence of membrane formed by PC but not in the presence of membrane formed by PE and/or PE methylated once and two times. Similarly, the voltage-dependence is recovered following the addition of 2% of phytosterol or 2% of PE or when the degree of methylation of choline decreases. The effect of sterols on the voltage-dependence is reversible. We have shown that the anion selectivity increases when the degree of methylation of choline decreases while the unitary conductance of the channel is invariable.<p>Our results indicate that lipid-protein interaction is essential for the regulation of the activity of VDAC channel. The nature of the lipids polar head is crucial for this regulation suggesting that it occurs at the membrane-solution interface.<p>The rest of our work has led us to study the effect of monovalent, divalent and trivalent cation on VDAC. We have shown that the voltage-dependence is lost in low concentrations of KCl (100 mM) and it is restored in the presence of 800 mmolale of KCl or 100 mM of calcium or 30 mM of lanthanum. These results suggest that the restoration of the voltage-dependence at low salt concentrations (100 mmolale) involve an electrostatic effect.<p> / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished

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Plusieurs études ont démontré l’impact de divers facteurs sur l’espérance de vie, dont les caractéristiques liées à l’environnement dans l’enfance et à l’âge adulte. L’objectif principal de ce mémoire est de déterminer si l’exposition à une épidémie durant la période fœtale ou pendant la première année de vie a un impact sur la survie après 40 ans pour les Québécois nés entre 1885 et 1901. Durant cette période, nous avons relevé des épidémies de variole et de scarlatine, ainsi qu’une pandémie de grippe, la grippe russe. L’influence d’autres facteurs sur l’âge au décès est également étudiée, celle du sexe, de l’année et de la saison de naissance, du lieu de résidence à la naissance (urbain ou rural) et des régions d’habitation dans l’enfance et à l’âge adulte. Les données sur les Canadiens français nés au Québec à la fin du XIXe siècle, soit l’échantillon de 5% des ménages du recensement canadien de 1901 (Sager 2001) recueilli par le Canadian Families Project, jumelées aux dates de décès à partir de l’index des décès de 1926 à 1996 de l’Institut de la statistique du Québec (ISQ) et de la Société de généalogie du Québec (Pilon-Marien et al. 2009; Gagnon et Bohnert 2012) ont été analysées. Plus spécifiquement, nous avons effectué une analyse descriptive de la population étudiée, puis une analyse multivariée à l’aide de modèles de Cox et de modèles de Gompertz. Il en résulte qu’une exposition à une épidémie avant l’âge d’un an augmente significativement le risque de décéder après l’âge de 40 ans. L’exposition pendant la période fœtale a également un effet négatif sur la longévité, toutefois cet effet n’est pas significatif dans les modèles fournissant le meilleur ajustement aux données. Enfin, une naissance pendant une épidémie, donc une exposition in utero et durant la première année de vie n’a pas d’impact négatif significatif sur l’âge au décès pour ceux qui survivent jusqu’à 40 ans. / Numerous studies have shown the effects on longevity of early life and adult conditions. The purpose of our study is to analyze the impact of exposure to an epidemic disease during the fetal stage or the first year of life on survival after age 40 for people born in Quebec between 1885 and 1901. During this period, we identified epidemics of smallpox and scarlet fever, and the Russian influenza pandemic. The effects on age at death of other environmental conditions have been studied such as the sex, the season of birth and the year of birth, the urban-rural status at birth, the region of residence in early life and the region of residence at death. The dataset used in this study is based on the 5 percent sample of the 1901 Canadian Census, gathered by the Canadian Family Project (Sager 2001). Individuals were matched to their deaths records through the Quebec Consolidated Deaths Index from the Société de Généalogie du Québec and the Index des décès from the Institut de la statistique du Québec (Pilon-Marien and al. 2009). A descriptive analysis of the population studied has been done and a statistical analysis with Cox models and Gompertz models was made. We observe that individuals who were exposed to an epidemic disease during their first year of life had an increased mortality after age 40. In utero exposure to an epidemic hints at an increase of mortality after age 40 but the effect is not significant. Also, a birth during a pandemic, and therefore exposure both in utero and in the first year, apparently has no significant negatives impacts on longevity.

Master Evil plans to rule the earth and set up his evil empire so that all may worship and adore him. However, six teenagers discover six crosses that have powers that will help them defeat the evil that will soon cross their path. Each cross possesses a quality of God that each of these teenagers must develop in order to stop Master Evil: faith, peace, salvation, truth, righteousness, and the Spirit. These six teenagers pose as a threat to Master Evil's plans, and he'll stop at nothing to defeat them and rule the world. It is the ultimate battle between good and evil. These six young people must have faith themselves and each other, but most importantly, they must have faith in God in order to defeat the ultimate evil.

Master Evil plans to rule the earth and set up his evil empire so that all may worship and adore him. However, six teenagers discover six crosses that have powers that will help them defeat the evil that will soon cross their path. Each cross possesses a quality of God that each of these teenagers must develop in order to stop Master Evil: faith, peace, salvation, truth, righteousness, and the Spirit. These six teenagers pose as a threat to Master Evil's plans, and he'll stop at nothing to defeat them and rule the world. It is the ultimate battle between good and evil. These six young people must have faith themselves and each other, but most importantly, they must have faith in God in order to defeat the ultimate evil.

This project is a discussion of the continuing need to address gender issues while teaching core curriculum in English classes at the secondary level.

This comparative study focuses on the detective genre and is conducted through literary analysis with a feminist critical perspective of two of its most iconic protagonists, Sherlock Holmes and Miss Marple, created by Sir Arthur Conan Doyle in 1887 and Agatha Christie in 1930 respectively. The purpose is to attempt to establish the effect of the gender differences on these two protagonists. Both Holmes and Miss Marple are deemed as iconic in the detective genre, but the protagonists do not have similar experiences and are created by authors of different genders. Thus, the focus is to explore how gender differences are represented in the literary texts A Study in Scarlet (1887), “A Scandal in Bohemia” (1891), and The Murder at the Vicarage (1930) when it comes to their work as detectives. By using a feminist critical perspective and with the help of previous research, the differences in three central issues, that is, work methods, attitudes and method of disguise, are established. The most prominent result from the analysis is that Miss Marple has to work independently from the police force and trust another character, Leonard Clement, with what she knows hoping that Clement will use her observations to make the case move forward. By contrast, Holmes is approached by clients and even assists the police force in investigations, while Miss Marple is dismissed because of gender discrimination and ageism when she reaches out to the police force. Miss Marple is clearly a victim of gender discrimination and ageism, while Holmes is seen as eccentric but fully competent as a detective. Holmes is even described as having “extraordinary powers” while Miss Marple is described as an “old pussy” in a derogatory manner. Therefore, the results are that there is a significant difference in attitude where Holmes as a man encounters more positive attitudes and Miss Marple as a woman encounters more negative attitudes, all because of gender discrimination and ageism. These results are of great importance as it reveals what gender differences Holmes and Miss Marple encounter in their literary texts. It opens up the opportunity for more research in gender differences and gender discrimination in comparisons between protagonists. That Miss Marple is successful in the end, however, functions as a feminist statement.

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