Quantitative resistance is controlled by multiple genes and has been shown to be a durable form of resistance to pathogens affecting cultivated crops including soybeans (Glycine max L. Merr). Root rot of soybean caused by Phytophthora sojae ranks among the most damaging soybean diseases. Quantitative resistance has proven durable in soybean against P. sojae, however the molecular mechanisms underlying this form of resistance are still unknown. The objective of this project is to gain insight into molecular basis of quantitative resistance in the soybean-P. sojae pathosystem. The approach was to use global transcriptional profiling based on microarray technology to identify genes that were differentially expressed in four cultivars of soybeans with varying levels of quantitative resistance at different time points during infection by P. sojae. Our results provide a better understanding of the potential regulatory factors that may contribute to quantitative resistance during early hours of P. sojae infection. / Ph. D.

Energy balance includes energy intake and energy expenditure. Either excessive food intake or insufficient physical activity will increase the body mass and cause obesity, a worldwide health problem. In the US, more than two-thirds of people are obesity or overweight. Conversely, it is well accepted that reducing energy intake can increase the life span and the resistance to age-related diseases. MicroRNAs are highly conserved non-coding RNA molecules with a length of 21-23 nucleotides. Recent studies show that numerous microRNAs are associated with the regulation of oxidative stress, inflammation, insulin signaling, apoptosis, and angiogenesis that relate to obesity. However, the role of microRNAs in the regulation of energy balance in central nervous system remains unknown, especially within the hypothalamus, a primary site of energy balance control. In this project, microRNA, and mRNA were profiled using microarray technology. Furthermore, quantitative proteomics were used to identify differential protein levels during fasting, and in a genetically obese mouse model, Mice were given either a 24-hour fast, or ad libitum access to food. Hypothalamic RNA and microRNA samples were analyzed by microarray, using both the Affymetrix and Toray 3D mRNA and microRNA platforms. No microRNAs were found to be differentially expressed between two treatments, whereas numerous mRNAs were significantly regulated by fasting, including 7 cell cycle related genes. Hypothalamic protein samples from WT and N2KO mice treated either to ad lib feeding or 24-hour fasting were analyzed by MSE quantitative proteomics. Over 650 proteins were identified with some proteins showing significantly different abundances between or among the four groups. Between ad lib fed WT and N2KO mice, 53 proteins were differentially expressed, with some of these linked to neurodegeneration, NAD synthesis, and the citrate acid cycle (TCA). Overall, the results of this study suggest that while microRNA-mediated mechanisms are not significant modulators of hypothalamic gene expression upon a 24 hour fast, cell cycle gene expression changes represent a major contributor to the fasting response. Moreover, Nlhl2 might play an important role in the neurodegeneration and mitochondrial metabolism. / Ph. D.

No / Purpose: The hollow fiber assay is used successfully as a routine in vivo screening model to quantitatively define anticancer activity by the National Cancer Institute. This study investigates whether the hollow fiber assay can be used as a short-term in vivo model to demonstrate specific pharmacodynamic end points, namely microtubule and cell cycle disruption. Experimental Design: The growth of A549 cells was characterized within hollow fibers over 5 days in vivo at both subcutaneous (s.c.) and intraperitoneal (i.p.) sites. Drugs were administered on day 4 (i.p.). Results: At 24 hours, cells were retrieved from fibers at both i.p. and s.c. sites of paclitaxel-treated (20 mg/kg) and combretastatin A1 phosphate¿treated (150 mg/kg) mice. Cell cycle analysis after paclitaxel treatment revealed a mean G2-M phase population of 48.04% (i.p.) and 25.76% (s.c.) compared with vehicle group mice (6.78 and 5.56%, respectively; P = <0.001 and 0.005, respectively). Tumor cells retrieved from combretastatin A1 phosphate¿treated mice had a mean G2-M phase population of 36.3% (i.p.) and 29.36% (s.c.) compared with cells retrieved from vehicle group mice (5.58 and 5.49%, respectively; P = <0.001). Using fluorescence and laser-confocal microscopy, paclitaxel was revealed to induce the formation of spindle asters and tubulin polymerization. Combretastatin A1 phosphate was shown to hold cells in mitosis. Changes in nuclear morphology were also observed. Conclusion: These data demonstrate that the hollow fiber assay can be used as a short-term in vivo model for studying the pharmacodynamic effects of both standard and novel compounds on microtubules. Evidence has also been provided to support the routine use of the in vivo hollow fiber assay for demonstrating the mechanism of action of a drug.

Depuis la publication de Decolonizing Methodologies, l'érudition méthodologique autochtone fut principalement alignée avec la recherche qualitative, tandis que la recherche quantitative est souvent délaissée en raison d'une méfiance associée aux méthodologies positivistes. Cependant, dans les récentes années, on observe une critique émergente des approches quantitatives de la recherche puisqu'elles placent les peuples autochtones dans un discours déficitaire. Effectivement, on note que les statistiques autochtones ont un caractère négatif qui met l'accent sur les différences, les disparités, les désavantages, les dysfonctionnements et les problèmes sociaux. Cette réalité est problématique puisque les statistiques qui proviennent des analyses quantitatives constituent la principale base de données probantes pour la politique autochtone. Par ailleurs, au Québec, on note que très peu de protocoles de recherche ont été établis par les organisations autochtones et communautés, que les formations éthiques sont inadéquates, etc. Dans ce contexte, ce projet de mémoire explore quels sont les stratégies et les obstacles à la décolonisation de la recherche quantitative au Québec. En somme, en analysant les stratégies et protocoles de recherche par les institutions québécoises et les organismes autochtones, on observe que la majorité des organismes mobilisent conjointement les principes de PCAP®, l'approche basée sur les forces et la recherche participative basée sur la communauté. Ainsi, dans l'absence des stratégies, dont les principes FAIR et CARE, on perçoit qu'au Québec les stratégies de décolonisation de la recherche ciblent autant les approches qualitatives que les approches quantitatives. Par ailleurs, les stratégies organisationnelles ciblent principalement les chercheurs dans leurs responsabilités individuelles envers les communautés, tandis que très peu mettent l'accent sur la nécessité d'apporter des changements institutionnels. En addition, nous identifions un ensemble d'obstacles en lien avec la difficulté de préserver l'anonymat, les difficultés de contrôler les données sur internet, le manque de donnée agrégée de qualité, les difficultés d'établir des relations collaboratives en raison de temps, de financement, de ressources humaines, le manque de mécanismes pour l'application de l'ÉPTC2, etc. / Since the publication of Decolonizing Methodologies, Indigenous methodological scholarship has primarily been aligned with qualitative research, while quantitative researchis often neglected due to a distrust associated with positivist methodologies. However in recent years, we have observed an emerging criticism of quantitative approaches toresearch because they place indigenous peoples in a deficit discourse. Indeed, indigenousstatistics are criticized for being highly negative and for emphasizing differences, disparities, disadvantages, dysfunctions, and social problems. This reality is problematicsince the statistics that come from quantitative analyzes constitute the main evidencebase for Indigenous policy. Furthermore, in Quebec, we note that very few research protocols have been established by indigenous organizations and communities, that ethicaltraining is inadequate, etc. In this context, this project explores the strategies and obstacles to the decolonization of quantitative research in Quebec. In short, by analyzingthe research strategies and protocols by Quebec institutions and Indigenous organizations, we observe that most organizations jointly mobilize the principles of OCAP®, the strengths-based approach and community-based participatory research. Thus, in theabsence of strategies, including the FAIR and CARE principles, we see that in Quebec the strategies for decolonizing research target both qualitative and quantitativeapproaches. Furthermore, organizational strategies mainly target researchers in theirindividual responsibilities towards communities, while very few emphasize the need tomake institutional changes. In addition, we identify a set of obstacles linked to the difficulty of preserving anonymity, the erroneous use of secondary data, publicly accessibledata or data protected by law, the difficulties of controlling data on the internet andthe emergence of cybercolonialism, the lack of quality aggregated data, the difficultiesof establishing collaborative relationships due to time, financing, human resources, theabsence of regulation of artificial intelligence, the lack of mechanisms for the applicationof TCPS2, etc.

The analysis of big data points and the use of data analytics have proven successful in improving corporate business efficiencies, growing profits, and increasing competitive advantages. The theory of academic capitalism, which holds that institutions of higher education are becoming more like corporations due to declining operating funds and the need to become more efficient, transparent, and competitive, guided this study. Despite the positive outcomes that analytic tools may produce in advanced efficiencies and competitive growth, college academic administrators have not yet adopted these tools, due in part to barriers facing the administrators. The purpose of this phenomenological study was to explore the nature of those barriers in a community college. Ten academic managers in 6 community college divisions who reported accountability for criterion-based key performance indicators were interviewed on their perceived use of academic analytic tools and barriers in adopting these tools. The interviews were collected and analyzed through preliminary grouping, reducing and eliminating outliers, clustering descriptions into categories, and constructing themes. The managers' narratives suggested that there were 4 perceived barriers that prevented the adoption of tools such as organizational bureaucracy (climate), restricted organizational data (policy), training, and infrastructure. An important area for further research involves identifying the strategies managers could use to overcome these barriers. The findings of this study will assist college administrators in implementing analytic tools. Such tools will improve key performance indicators, resulting in a more cohesive and cost-effective academic experience for students, faculty, administrators, and the community.

Organizations that employ physically demanding jobs want to ensure their selection procedures distinguish qualified applicants from unqualified applicants. However, such selection tools typically result in adverse impact against various protected groups and often lead to litigation. Various factors influence the court’s decision to rule in favor of the plaintiff or the defendant. The purpose of the present study is to identify those factors. The ADA (1990) created strict guidelines for plaintiffs and defendants to follow to be credible in a discrimination case. This study will specifically determine the impact of the ADA guidelines and three additional factors that influence court decisions including job analysis and test validation procedures, and whether the job involves public safety. Organizations can benefit from knowing factors they can control to decrease legal liability. Cases filed from 1992 to the present were reviewed and coded based on each factor. Z-tests for proportions were conducted to determine the proportions of rulings in favor of the plaintiff and defendant based on each factor of interest. Public safety influences the court decisions in favor of the defendant, such that for jobs in which public safety is of concern, the court is more likely to rule in favor of the defendant. Additional factors were not significantly influential. However, some trends are apparent and discussed in the paper. Implications and limitations also are discussed.

No description available.

Nous proposons dans cette thèse plusieurs contributions relatives à la vérification quantitative des systèmes. Cette discipline vise à évaluer les propriétés fonctionnelles et les performances d'un système. Une telle vérification requiert deux ingrédients : un modèle formel de représentation d'un système et une logique temporelle pour exprimer la propriété considérée. L'évaluation est alors faite par une méthode statistique ou numérique. La complexité spatiale des méthodes numériques, proportionnelle à la taille de l'espace d'états, les rend impraticables si les systèmes présentent une combinatoire importante. La méthode de comparaison stochastique basée sur les chaînes de Markov censurées réduit la mémoire occupée en restreignant l'analyse à un sous-ensemble des états de la chaîne originale. Dans cette thèse nous fournissons de nouvelles bornes dépendant de l'information disponible relative à la chaîne. Nous introduisons une nouvelle logique temporelle quantitative appelée Hybrid Automata Stochastic Logic (HASL), pour la vérification des processus stochastiques à événements discrets (DESP).HASL emploie les automates linéaires hybrides (LHA) pour sélectionner des préfixes de chemins d'exécution d'un DESP. LHA permet de collecter des informations élaborées durant la génération des chemins, fournissant ainsi à l'utilisateur un moyen d'exprimer des mesures sophistiquées. HASL supporte donc des raisonnements temporels mixés avec une analyse à base de récompenses. Nous avons aussi développé COSMOS, un outil qui implémente la vérification statistique de formules HASL pour des réseaux de Petri stochastiques. Les ateliers flexibles (FMS) ont souvent été modélisés par des réseaux de Petri. Cependant le modélisateur doit avoir une bonne connaissance de ce formalisme. Afin de faciliter cette modélisation nous proposons une méthodologie de modélisation compositionnelle orientée vers les applications qui ne requiert aucune connaissance des réseaux de Petri. / We propose in this thesis several contributions related to the quantitative verification of systems. This discipline aims to evaluate functional and performance properties of a system. Such a verification requires two ingredients: a formal model to represent the system and a temporal logic to express the desired property. Then the evaluation is done with a statistical or numerical method. The spatial complexity of numerical methods which is proportional to the size of the state space of the model makes them impractical when the state space is very large. The method of stochastic comparison with censored Markov chains is one of the methods that reduces memory requirements by restricting the analysis to a subset of the states of the original Markov chain. In this thesis we provide new bounds that depend on the available information about the chain. We introduce a new quantitative temporal logic named Hybrid Automata Stochastic Logic (HASL), for the verification of discrete event stochastic processes (DESP). HASL employs Linear Hybrid Automata (LHA) to select prefixes of relevant execution paths of a DESP. LHA allows rather elaborate information to be collected on-the-fly during path selection, providing the user with a powerful mean to express sophisticated measures. In essence HASL provides a unifying verification framework where temporal reasoning is naturally blended with elaborate reward-based analysis. We have also developed COSMOS, a tool that implements statistical verification of HASL formulas over stochastic Petri nets. Flexible manufacturing systems (FMS) have often been modelized by Petri nets. However the modeler should have a good knowledge of this formalism. In order to facilitate such a modeling we propose a methodology of compositional modeling that is application oriented and does not require any knowledge of Petri nets by the modeler.

En forêt tropicale humide Amazonienne, les facteurs gouvernant l'évolution des espèces d'arbres restent peu connus et continuellement débattus. En particulier, les micro-variations environnementales attirent beaucoup d'attention car elles induisent de profondes modifications de structure et composition des communautés. Les variations micro-environnementales associées à la topographie ont couramment été évoquées comme facteur de radiations adaptatives chez les espèces d'arbres. Cependant, l'hypothèse de l'adaptation locale n'a jamais été testée au niveau intra-spécifique chez les arbres de forêt amazonienne alors que l'on sait que la diversité génétique des arbres tropicaux est couramment structurée à faibles échelles spatiales par des processus neutres (en particulier du fait de restrictions de flux de gènes). Dans cette étude, j'ai étudié le processus de différentiation génétique d'une espèce d'arbre (Eperua falcata, Fabaceae) dans les paysages forestiers de Guyane française grâce à la combinaison d'une approche phénotypique (génétique quantitative) et d'une approche moléculaire (génétique des populations). Je me suis attachée à répondre à trois questions principales : 1) Comment se distribue la diversité génétique dans les paysages forestiers de Guyane française ? 2) Quelles forces évolutives sont impliquées dans le processus de différentiation génétique à faible échelle spatiale ? 3) Est-ce que le processus d'adaptation locale contribue à structurer la diversité génétique à faible échelle spatiale ? / In the tropical rainforest of Amazonia, the factors driving the evolution of tree species remain poorly understood, and the relative influence of neutral and adaptive processes is continuously debated. In particular, local habitat patchiness draws much attention, as profound changes in the structure and composition of forest communities occur among micro-habitats. Thus, micro-environmental variations related to topography have frequently been invoked as drivers of adaptive radiation leading to sympatric speciation in Neotropical trees. On one hand, the hypothesis of local adaptation has never been investigated at the intra-specific level, i.e. within species currently undergoing population differentiation; on the other hand, many tree species are genetically structured over local scales due to neutral processes, mainly limited gene flow (caused by restricted pollen and seed dispersal). In this study, I used populations of a common tree species of the Guiana Shield - Eperua falcata (Fabaceae) - to study how neutral and adaptive processes shape the distribution of genetic diversity across forest landscapes characterized by local micro-habitat patchiness. I asked three main questions by combining both phenotypic (quantitative genetics) and molecular (population genetics) approaches: 1) How is the genetic diversity structured in forest landscapes of French Guiana? 2) Which evolutionary drivers are relevant to explain the structure of genetic diversity at local scale? 3) Does local adaptation contribute to structure genetic diversity within continuous populations?

La maladie de taches noires (TN ; champignon Leptosphaeria lindquistii) est une maladie importante en France. L'étude présentée dans cette thèse fournit des informations utiles sur l’épidémiologie de TN et sur la résistance quantitative du tournesol contre TN. Des expérimentations ont été menées sur petites parcelles au champ, plantes adultes (serre), et plantules (phytotron) pour (1) caractériser la dynamique spatiotemporelle de TN, (2) identifier les traits morphologiques affectant TN via des processus d’esquive de la maladie et en utilisant une procédure standardisée d'évaluation de la maladie, et (3) identifier des prédicteurs de résistance quantitative à TN. Cette étude suggère que (1) TN est associée à des épidémies monocycliques dans le sud ouest de la France, (2) les niveaux faibles de TN sont associés à des plantes ayant un grand nombre de feuilles vertes et de de grande taille, et (3) des prédicteurs de résistance quantitative à BS peuvent être identifiés expérimentalement. / Phoma black stem (BS) is caused by the fungus Leptosphaeria lindquistii, and is an important disease in France. The study presented in this dissertation provides useful information on BS epidemiology and sunflower quantitative resistance against the disease. Experiments were conducted on plants grown in small plots (field), adult plants (greenhouse), and seedlings (growth chamber) in order to (1) characterize the spatiotemporal dynamics of BS, (2) identify morphological traits affecting BS through disease escape processes and utilizing a standardised disease assessment procedure, and (3) identify predictors of quantitative resistance to BS. This study suggests that (1) BS is primarily associated to monocyclic epidemics in south west France, (2) low BS levels are associated with sunflower plants characterized by a large number of green leaves and large height, and (3) predictors of quantitative resistance to BS can be experimentally identified.