In order to determine the effects that Maillard Reaction Products (MRP) have on Salmonella Typhimurium, growth rates and virulence expression, in the presence of Maillard reaction products, were observed, using the β−galactosidase Miller Assay and Reverse Transcription Polymerase Chain Reaction (RT-PCR). The presence of MRP compounds in liquid media caused no negative effect on the growth rate of Salmonella cells. However, the addition of MRP compounds at a 1% level in the media caused a significant increase in hilA expression in Salmonella Typhimurium, and the highest induction levels were observed in media supplemented with arginine and histidine-MRP compounds. There was no effect on the induction of hilA with the 0.5% addition of the MRP compounds in the amended media as shown by the Miller Assay. However, there was an effect seen when using the Real Time RT-PCR assay that resulted in the same levels of significance seen at 1.0% additions of MRPs being seen at the 0.5% level as well. Since rsmC was shown to be a constitutive gene that had continuous levels of expression in Salmonella based on cell number, Real-Time PCR was then used to assess the hilA expression of Salmonella Typhimurium under different oxygen, pH levels, and osmolarity conditions. The results under low oxygen indicate that the combination of low osmolarity and high pH have the highest inducing effect on hilA expression. The hilA response under the same media conditions and a high oxygen environment showed the same pattern of expression as those bacteria grown under a non-aerobic environment. The media with a pH of 8 and low osmolarity conditions had the greatest effect on the induction of hilA with none of the other media showing any significant effect. The relative expression of hilA did decrease for those bacteria grown under aerobic conditions versus those grown under low oxygen conditions.

The effect of heat shock was observed on the expression of hilA in Salmonella Typhimurium by creating a fluorescence-based reporter strain of Salmonella and by realtime reverse transcriptase polymerase chain reaction (RT-PCR). The hilA gene in Salmonella is known to play an important role in its pathogenesis. hilA is known to be activated when the bacteria encounter stress-inducing conditions. A number of factors have been identified that affect hilA expression, such as, pH, osmolarity, oxygen tension. When Salmonella enter their warm-blooded hosts, they encounter an increase in temperature. Therefore, heat is another stressor that is encountered by Salmonella during infection of their hosts. A fluorescence-based strain of Salmonella was created to study the effect of heat shock. The gene for green fluorescent protein (gfp) was placed under the control of the promoter of hilA on a plasmid. This plasmid was used to transform Salmonella cells to create a fluorescent strain. In this strain, when the hilA promoter is activated, gfp is transcribed, which encodes the green fluorescent protein. This protein can be measured by a fluorescence assay. The results of this study indicated that at 45ºC, hilA is activated. RT-PCR was used to look at hilA expression at different temperature. The results of this study indicated that, compared to 37ºC, higher temperatures like 45ºC and 55ºC significantly activate hilA.

Cette thèse s’intéresse aux processus de conscientisation d’enseignants travaillant auprès d’enfants à risques dans le programme HILA en Israël. Le programme HILA est destiné aux enfants ayant décroché du système éducatif, et sont en situation de haut risque. La conscientisation des enseignants sera définie dans la thèse par leur conviction dans la possibilité des élèves à atteindre la réussite scolaire et à changer l’image qu’ils ont d’eux-mêmes, malgré leurs échecs passés et les risques auxquels ils sont exposés. La thèse se fonde sur des entretiens biographiques avec des enseignants et sur la confrontation de ceux-ci avec deux théories principales traitant de la conscience des enseignants : la pédagogie critique et l’éthique de la sollicitude. Elle analyse également les conceptions pédagogiques européennes antérieures à la deuxième guerre mondiale pour les comparer aux théories examinées. La thèse formule des déductions concernant les éléments motivant la conscientisation des enseignants en situation de travail , ainsi qu’une critique des théories prises en considération. L’une des importantes déductions de la thèse est que la conscientisation des enseignant exige d’appréhender ceux-ci comme des agents de changement. Tout d’abord, les enseignants sont eux-mêmes opprimés. Ils servent le même système oppressif qui provoque le décrochage continu des élèves. Deuxièmement, l’aspiration des enseignants à guider la réussite de ces mêmes élèves, fait partie de leur désir de guérison individuelle ou de réparation de la société - et ce, malgré les écarts considérables entre leurs différentes visions du monde. Les enseignants voient dans leur rôle une vocation. La théorie de la pédagogie critique contribue fortement à la compréhension du contexte oppressif des élèves, mais omet de prendre en considération l’oppression vécue par les enseignants. Elle ne peut donc formuler/ proposer de théorisation de la conscientisation qui prendrait le sujet en compte. L’éthique de la sollicitude, elle, sonde le sujet et se rapproche ainsi bien plus du décryptage de la conscientisation. En revanche, il lui manque toute la dimension que donne le contexte éducatif et social.La thèse conclut finalement qu’une théorie pédagogique pouvant pleinement expliquer la conscientisation des enseignants est un travail qui reste encore à faire. / This dissertation deals with processes of conscious change among teachers working with students at risk in the HILA Program in Israel. The HILA program is designated for children and youth who dropped from the educational system and are in high risk. In this work, conscious change is defined as a teacher's belief in his or her students’ ability to succeed in school and to change their self-image, despite past failures and conditions of risk they had been exposed to. Biographical interviews serve as a main primary source in this dissertation. They are analyzed according to two critical theories in the field which focus on teachers’ consciousness: the Critical Pedagogy Theory and the Ethics of Care Theory. Additional pedagogical concepts, developed in Europe in the interwar period, are considered in relation to those critical theories. This dissertation offers a new critique of the conventional theories in the field, in addition to a discussion of the factors which may produce conscious change among teachers of students at risk. The first argument is that, in order to understand conscious change among teachers, one must view teachers as agents of change. Secondly, teachers should be seen as oppressed individuals themselves – they serve an oppressive system which encourages students from certain backgrounds to drop. Third, it is argued that teachers have a clear interest to lead their students to success as part of a process of self-improvement or social correction; in spite of differences in their world views, the vast majority of teachers see their job as a mission. Finally, while the Critical Pedagogy Theory helps to understand the broader social context of the oppression experienced by students at risk, it fails to see teachers as oppressed individuals as well. The Ethics of Care Theory, on the other hand, comes much closer to deciphering the process of conscious change since it takes the individual into account, although it lacks a deep understanding of the social and educational contexts. Therefore, this thesis concludes that we still have a long way to go before developing a pedagogical theory which will successfully explain conscious change among teachers.