McGill University Thèses et mémoires publiés en 2011

L'inactivation des gènes clk-1 et isp-1, codant tous deux pour des protéines mitochondriales impliquées dans le processus de phosphorylation oxydative, a été démontrée comme augmentant la durée de vie du nématode Caenorhabditis elegans. La présente étude décrit les effets résultants de l'inactivation des homologues de ces gènes chez les mammifères sur le processus du vieillissement ainsi que sur une des principales pathologies reliées au vieillissement, l'artériosclérose. Les souris ne possédant qu'une seule copie fonctionnelle du gène Mclk1, l'homologue du gène clk1 qui code pour une enzyme impliquée dans la formation de l'ubiquinone, ont été montrées comme vivant plus longtemps que …  Lire la suite

Limiter le montant de dilution dans le flux de processus est l'objectif de toute exploitation minière. Les méthodes d'exploitation minière en veine mince par retraite longitudinal sont particulièrement sensible à la dilution en raison de la forme élancée des chantiers. Comprendre les facteurs qui influencent la stabilité de ces murs peuvent aider un ingénieur des mines a réduire au minimum la dilution. Cette thèse présente les resultants d'une étude visant à examiner ces facteurs d'influence et révèle les processus utilizes pour construire un modèle empirique permettant d'estimer la dilution pour un chantier spécifique. Ce travail est centré sur une étude …  Lire la suite

Park, Jeeseon (Internal/Cosupervisor2)  Lire la suite

RésuméCette étude constitue une exploration de l'histoire et de la pratique d'un service infirmier de télétriage, Info-Santé. Un aperçu de l'évolution historique du service Info-Santé à la suite des coupures faites dans le système de soins de santé québécois vient situer l'étude dans les contextes social et politique élargis. Ce regard porte sur la période des coupures qui s'étend du début au milieu des années 1990; il prend en considération les changements structuraux qui en ont découlé sur le plan de la prestation des soins de santé. Il est aussi question de la division du travail dans le système des …  Lire la suite

Il est essentiel, chez les expériences modernes de physique des hautes énergies, de pouvoir comparer les résultats obtenus des cacluls Monte Carlo aux résultats provenant de données expérimentales. Le facteur d'échelle de l'efficacité du «b-tagging» (FE) permet de faire une comparaison légitime entre l'identification des b quarks dans des échantillons de données et des échantillons de Monte Carlo. Cette thèse présente une mesure simultanée du FE (pour l'algorithme SecVtx) et de la section efficace de la production de ttbarre, utilisant 5.6 fb^{-1} de données de collision ppbarre à √s = 1.96 TeV. Ces données furent accumulées par l'expérience «Collider Detector …  Lire la suite

The main focus of the study was on three ionophoric antibiotics, monensin salinomycin and narasin. These three pharmaceuticals were evaluated both in vivo and in vitro setups to understand their fate and behavior in a constructed wetland (CW) environment. The laboratory studies determined the sorption, degradation and photodegradation potential in context of a wetland setup and, the field-scale CW experiments appraised the pharmaceutical removal potential under three flow configurations: free water surface (FWS), horizontal subsurface flow (HSSF) and vertical flow (VF) systems. FWS and HSSF systems were evaluated with two texturally different soils while the vertical system employed sphagnum peat …  Lire la suite

Breast cancer is a major health problem. Metastatic disease is generally incurable. In the majority of patients, the skeleton bears the major metastatic burden. Bony lesions of metastatic breast cancer are usually osteolytic. Osteolytic metastases are formed by the pathological activation of osteoclasts. Anti-osteoclastic drugs are standard of care for patients suffering from breast cancer metastases. We conducted this project to decipher the signalling mechanisms responsible for osteoclasts activation in response to exposure to mediators released from mammary carcinoma cells. We evaluated the apoptotic profiles of osteoclasts in vitro in the presence of soluble factors derived from mammary carcinoma cells …  Lire la suite

Fergusson, Dean (Supervisor2)  Lire la suite

While most studies of Islam in West Africa have focused on the spread and nature of Sufi Islam, there has been a recent dramatic transformation in the political and social influence of Sufi Islam long-believed to characterize "African Islam." The forces of globalization and social and economic changes in West Africa and beyond have resulted in parallel transformations across the Islamic world. In northern Ghana, where Sufi Islam has long been the dominant form of religious practice and politics, the advent of a new, more orthodox, form of Islamicization has taken place that has not yet been adequately studied. One …  Lire la suite

Le but de cette thèse est d'illustrer l'évolution institutionnel du premier ministre au Canada, avec emphase sur le rôle joué par la psychologie individuel en déterminant les résultats politiques. Ainsi, ce project à deux objectifs complémentaires, soit théoretiques et empiriques. Le premier soutient le pouvoir explicatif supérieur de l'individualisme méthodologique contre les explications alternatifs, qui subsument les acteurs politiques aux dynamiques agrégatifs et l'agence humaine obscur. L'analyse empirique vérifie cette hypothèse en examinant comment l'institution du premier ministre a changé pour reflecter les personnages ce certains premiers ministres: John A Macdonald (1867-1873, 1878-1891), William Lyon Mackenzie King (1921-1930, 1935-1948), et …  Lire la suite

This thesis examines how small players change mature organizational fields. Mature fields are characterized by stable pre-existing institutional logics, interlocked relationships between participants, and high levels of practice standardization. In this thesis, I look at the emergence, diffusion, and legitimation of new, niche practices and their embodied logic within the Canadian wine field in the past 30 years. The first phase of this thesis provides a theoretical framework of how niche practices spill over to mainstream markets in mature organizational fields. The second phase is an inductive, theory-building effort to specify how small players change mature organizational fields. Based on …  Lire la suite

Pervious concrete is an innovative material with several environmental advantages. Studies on the properties and performance of ordinary Portland cement (OPC) pervious concrete have been done worldwide. Portland limestone cement (PLC) has recently been introduced into the Canadian market as a greener option than OPC. This thesis explores the possibility of using PLC in pervious concrete to achieve technical and environmental benefits.Since the major application of pervious concrete is pavements, it is important to find a way to accelerate the concrete curing process, as one of the most important factors in determining the cost and impact of road work is …  Lire la suite

Mammalian alkali cation/proton exchangers, more commonly known as sodium/proton exchangers (NHEs) are a family of transmembrane proteins that mediate an electroneutral exchange of Na+ (or K+) and protons across cellular membranes, thereby regulating intracellular pH and volume homeostasis. Eleven different isoforms have been identified, which differ in their tissue distribution, subcellular localization, and function. The organellar-type NHE6 isoform is widely distributed in tissues, but is enriched in brain, heart, and muscle. In order to elucidate the native distribution of NHE6 and to identify some of the mechanisms underlying its trafficking and function, a rabbit polyclonal antibody was generated. Utilizing this …  Lire la suite

This thesis is a study of the Laozi zhongjing, an early medieval Chinese text, preserved in the Daoist Canon (Daozang) in two versions. In the first chapter, I compare the extant versions, inquiring into the relationship between them, and then establish the interval for the text's possible dates of composition. In the second chapter, I argue that the text was deliberately written as an esoteric scripture and analyze the techniques which the text uses to create an atmosphere of secrecy; I then suggest that the best way to approach an esoteric scripture consists in scrutinizing the text in order to …  Lire la suite

La production de la fructosyltransférase (lévansaccharase) par la souche thermophilique Geobacillus stearothermophilus a été investiguée à 55oC pendant 32 h de fermentation dans un milieu de culture minéral supplémenté avec diverses sources d'azote, de fer et de carbones pour l'induction. Les sources d'azotes organiques, tryptone et peptone, ont conduit à une croissance bactérienne optimale et une production maximale de la lévansaccharase. Toutes les sources de carbones utilisées sont parvenues à induire la production de la lévansaccharase, avec le saccharose (1% m/v) étant l'inducteur le plus efficace. L'addition d'une source férrique ou ferreuse n'a eu aucun effet significatif ni sur la …  Lire la suite

Abrahamowicz, Michal (Supervisor1)  Lire la suite

Depuis quelque temps, les contrôleurs de jeux vidéo évoluent en instruments à bases de capteurs qui suivent les mouvements dynamiques et naturelles, et imitent les instruments utilisés dans la vie de tous les jours. La popularité soudaine de ce type de contrôleurs nous mène à considérer si cette nouvelle manière d'interaction naturel va devenir la norme pour l'avenir du divertissement électronique. Cette notion nous a inspiré à investiguer la préférence de l'interaction physique versus les modes virtuels conventionnels. Pour accomplir ceci, un système prototype multiutilisateur a été développé en utilisant des composantes matérielles commerciales à prix modiques. Notre système comprend …  Lire la suite

This thesis critically appraised the Cerebellar Deficit Theory (CDT) which claims to provide a parsimonious explanation of the two most prominent existing cognitive deficit theories of dyslexia, namely the phonological and the speed naming deficit theories. Specifically, a mild congenital cerebellar deficit is proposed to give rise to a series of impairments that eventually lead to difficulties in rapid naming, phonological processing and reading. Conceptual problems with the theoretical model behind the CDT were first identified and discussed. The behavioral evidence related to CDT was then evaluated. Following this evaluation, four major questions related to CDT were examined: (1) Was …  Lire la suite

Fitzpatrick, Marilyn R. (Supervisor1)  Lire la suite

Le conseil de l'Aréopage était une des institutions les plus anciennes et les plus respectées d'Athènes. Son origine, son importance et ses fonctions demeurent ambigües en dépit des efforts des historiens anciens et modernes. La plupart des travaux modernes sur l'Aréopages se concentrent sur des événements isolés dans l'histoire de ce conseil ou sur les particularités de ses pouvoirs. Cela a donné lieu à une série d'études spécifiques qui, lorsqu'on les considère individuellement, ne sont pas d'un grand secours aux historiens pour apprécier le rôle d'ensemble de l'Aréopage dans la culture politique d'Athènes. Cette enquête réexaminera les sources littéraires et …  Lire la suite

This thesis examines systematic sources of variance in raters' judgments of second (L2) language speech, including rater cognitive and experience variables, rating scale properties, and characteristics of the speech, in order to better understand influences on raters' scoring decisions. The thesis culminates in the development of an empirically-based L2 comprehensibility scale that describes, with greater precision, the quality of speech that is characteristic at different comprehensibility levels. Study 1 examines the effect of individual differences in raters' cognitive abilities on their ratings of L2 speech. Thirty music majors and 30 non-music majors rated 40 L2 speech samples for comprehensibility, accentedness, …  Lire la suite

The objective of this work was to examine the hydration performance of Portland cement with variations in their Tricalcium Silicate and Tricalcium Aluminate phases. The performance of Portland cement is affected by its particle size, chemistry, morphology, water availability, thermodynamic reaction rates, and age at which the materials are tested. The majority of research on Portland cement hydration has thus far evaluated each of its different components independently by examining how those phases react with water over time. However, Portland cement has many phases that are all reacting simultaneously depending on many different factors. How the different phases react while …  Lire la suite

Lands, Larry (Supervisor2)  Lire la suite

L'ingénierie des cristaux de solides moléculaires est un domaine en plein essor, combinant de nombreux aspects de la chimie des matériaux. Il est d'une grande importance pour l'électronique, la nanotechnologie ainsi que pour l'industrie pharmaceutique, ou il y a grand besoin de concevoir des réseaux ordonnés de molécules. Alors que la synthèse organique donne accès à un grand éventail de molécules, le contrôle des interactions intermoléculaires entre celles-ci est le défi pris en charge par l'ingénierie des cristaux. Cette thèse se concentre sur l'auto-assemblage d'acides carboxyliques en surface, en utilisant ce dernier comme modèle pour étudier les facteurs généraux gouvernant …  Lire la suite

Hamdy, C Reggie (Supervisor2)  Lire la suite

Curtis, Mark A. (Supervisor1)  Lire la suite

This dissertation is a study of gender transitivity as I see it at work in three of Robert Schumann's dramatic works: the Szenen aus Goethes Faust, WoO 3, the opera Genoveva op. 81, and the oratorio Das Paradies und die Peri op. 50. In this study, I use the term gender transitivity to refer to the fluid movement along feminine and masculine subject positions. While on the surface Schumann created seemingly passive, Gretchen-like female characters in his dramatic works, he also worked with pluralistic ideas about gender drawn from his extensive knowledge of early nineteenth-century literature and philosophy. He explored …  Lire la suite

This thesis examines the physical descriptions - or portraits - of the characters in À l'ombre des jeunes filles en fleurs. It explores the paradox in which these descriptions both build and reveal the characters, and, at the same time, blur them into unrecognizable personalities. The thesis is divided into two sections. The first one deals with the construction of our perception of body images through the examination of Proust's descriptive techniques. The second section discusses the "defeat of the portrait" as an epistemological tool. In particular, this section looks at the "interference" (caused by optical illusions, subject movement or …  Lire la suite

Joseph, Lawrence (Supervisor2)  Lire la suite

The concept of angiogenesis, the formation of new blood vessels from preexisting vessels, is simple and well defined but the execution of this concept is highly complex, involving factors that are poorly understood. What we certainly know, is that angiogenesis is a vital component of life and death; life with respect to the development of the cardiovascular system in the early embryos, and death when angiogenesis occurs in an uncontrollable manner such as during tumor development. Mechanotransduction is the translation of mechanical forces into a signaling cascade that leads to the activation of genes. The vascular endothelial growth factor (VEGF) …  Lire la suite

Located between diplomacy and military action on a scale of intervention, economic sanctions are assumed to be an effective tool to influence global politics. However, assessments of the success of economic sanctions generally indicate that, in most cases, they fail to bring about the desired outcome. Rather, economic sanctions usually hit the wrong targets with innocent civilians often paying the price instead of the ruling elites and their collaborators. Among sectors targeted by economic sanctions, measures taken against civil aviation may place people, airlines, and cities inside and outside the sanctioned country at risk, and consequently may have ramifications on …  Lire la suite

Amabili, Marco (Internal/Cosupervisor2)  Lire la suite

This study examined two different strategies of learning with diagrams: drawing diagrams while learning or learning from pre-constructed diagrams. One hundred ninety six junior high school students were randomly placed in a condition either to draw while learning about how airplanes fly or to study from pre-constructed diagrams. Before the learning, students' prior knowledge and elaboration strategies were measured. During learning in either condition, students reported their mental effort. Afterwards, students' learning was tested on both a similar task and transfer task. Cook's (2006) theoretical framework, which combines prior knowledge and cognitive load theory on visual representations in science education, …  Lire la suite

The cardiovascular system is the first fully functional organ system in the vertebrate embryo. Proper formation of the vasculature is essential for proper embryonic development. Blood flow plays a significant role in the adaptable characteristics of the vessels, as well as innetwork remodelling. As soon as blood flow begins, vessels respond to external stimuli such asshear stress, the tangential force created by the blood flow, which affect the surrounding tissue. Shear stress is the product of both the velocity profile in the vessel and the viscosity of the flowing fluid, and these parameters were determined in vivo. In this research, …  Lire la suite

Au cours des dernières années, plusieurs systèmes d'enseignement assisté par ordinateur ont été développés pour une variété d'instruments de musiques. Cependant, il n'y a toujours pas de développements considérables d'un système éducatif qui soit dédié à l'apprentissage de la basse électrique. Une grande partie des systèmes existant misent beaucoup sur la technologie sans chercher à motiver l'élève en intégrant l'élément de participation interactive que peut générer un jeu électronique éducatif.Ce mémoire présente la conception d'un système d'enseignement de haut niveau qui examine les éléments du jeu dans le cadre de l'apprentissage de la basse électrique. Afin d'établir les fondements de …  Lire la suite

Les protéines phosphatases agissent sur plusieurs substrats qui participent dans différents procédés dans les cellules de mammifères tel que le métabolisme du glycogène, la progression du cycle de la division cellulaire, la différenciation cellulaire, l'apoptose, la synthèse des protéines et la transduction du signal (Cohen, 2002; Berndt, 1999; Shenolikar, 1994). L'isoforme alpha de la protéine phosphatase de type 1 (PP1) peut jouer un rôle important dans la différenciation neurale. Nous avons démontré que le degré de phosphorylation de la PP1 affecte le degré de différenciation des cellules PC12 suite à un traitement au NGF. Cependant, la nécessité de la phosphorylation …  Lire la suite

In this study, the near-limit propagation of detonations in annular channelsis investigated. Stoichiometric mixtures of methane-oxygen, acetylene-nitrousoxide diluted with 50% argon and acetylene-oxygen diluted with 70% argon areused in the experiments. Detonation velocity as well as smoked foil records ofnear-limit detonations are obtained. It is found that by normalizing the channellength scale by the ZND reaction length, ( i.e. L/ΔZND, where L is the channelgap) the velocity variations for different channels coalesces to a single curve.Thus the detonation velocity in annular channels depends on the relative rolebetween the geometry and the chemical sensitivity of the mixture. Detonationvelocities of the order …  Lire la suite

The biggest challenge to islet transplantation is preserving cell mass and function. It is known that the stresses encountered during islet isolation have deleterious effects on beta-cell physiology. The nature of these effects, however, are incompletely known, partly due to the heterogeneity of islet preparations. Using a combination of laser capture microdissection and microarray technology, we therefore sought to determine the beta-cell specific events that occur as a result of islet isolation and in vitro culture. Our data shows that islet isolation and in vitro culture induce a large inflammatory response that is NF-kB dependent and involves the upregulation of …  Lire la suite

The work described involves the study of shock-induced reactions in binary/heterogeneous reactive powder mixtures that produce little or no gas and the possibility that a detonation could be produced in such mixtures. The first task was to identify the mechanism by which these mixtures reacted when shocked. Critical initiating shock pressure and autoignition temperature were determined for a number of mixtures by recovery of shocked samples and differential thermal analysis, respectively. In addition, recovery experiments using Mn+S in two different charge geometries and at two different nominal densities (60% TMD and 90% TMD) were carried out to study the effect …  Lire la suite

Biological evolution is unlike other topics in science. For many students, it is emotionally-charged and conceptually difficult, and yet it is vital to making sense of biology. Considerable research has addressed the unique challenges of teaching evolution, but it has left many questions unanswered. In this thesis, I will provide an overview of the literature on strategies for teaching evolution with an emphasis on those for which there is empirical support. Conclusions that may be drawn from this literature and limitations of the studies will be discussed. Based on the findings, I will argue that the best approach to evolution …  Lire la suite

La sclérodermie systémique ou la sclérodermie (SSc), est une maladie auto-immune du tissu conjonctif qui est rare et chronique. Elle est caractérisée par des défigurements importants et visibles des parties du corps socialement pertinentes, tels que la bouche, le visage, et les mains. Il n'existe aucun remède pour la SSc et les traitements atténuent à peine les changements physiques défigurants qui peuvent être importants et difficiles à dissimuler. Il y a très peu de recherches faites sur la défiguration et sur les préoccupations de l'image corporelle chez les personnes atteintes de la SSc. La recherche actuelle se compose de deux …  Lire la suite

In this thesis, we present the first-principle calculations of inelastic electron tunneling spectroscopy(IETS) in single molecular break junctions. In a two-probe electrode-molecule-electrode setup, density functional theory(DFT) is used for the construction of the Hamiltonian and the Keldysh non-equilibrium Green's function(NEGF) technique will be employed for determining the electron density in non-equilibrium system conditions. Total energy functional, atomic forces and Hessian matrix can be obtained in the DFT-NEGF formalism and self-consistent Born approximation(SCBA) is used to integrate the molecular vibrations (phonons) into the framework once the phonon spectra and eigenvectors are calculated from the dynamic matrix. Geometry optimization schemes will also …  Lire la suite

Social networks play an increasingly important role on the behavior of communication on the Internet. We present a general framework called socially governed networks that provides a network protection scheme at the level of social individual/social organization instead of the traditional level of physical address. The functionalities of socially governed networks are mainly composed of two parts: social accountability and social computation based security policy generation. For social accountability part, we design Gates (Personal Gate and Social Gate) binding users' actions on the Internet with users' social identities issued by given online social network (such as Facebook) instead of physical …  Lire la suite

This thesis presents a study of optimal threshold designs for energy-detection based spectrum sensing in a cognitive-radio network with a pair of Primary-User (PU) transmitter-receiver and a pair of Secondary-User (SU) transmitter-receiver uniformly distributed in their corresponding transmission and interference ranges. Both large-scale path-loss and small-scale fading are considered in the wireless channel model. At first, the optimization problems under three criteria: Risk Minimization, Cost Minimization, and Capacity Maximization are formulated for SU with narrowband sensing capability. Derived under Bayesian framework, Risk Minimization threshold aims to minimize the sum of the miss detection and false alarm probabilities while Cost Minimization …  Lire la suite

The fundamental motivation for the work in this thesis is the study of decentralized dynamical decision systems and their optimization properties. The design of competitive markets to substitute for traditional centralized regulation has been considered in many domains and a key feature of the decentralized decision mechanisms of competitive markets is that, subject to certain hypotheses, they maximize social welfare. Progressive auctions constitute a highly developed form of such market mechanisms and hence in this thesis we construct and analyze them as paradigm examples of decentralized dynamical decision making systems.In the work of Lazar and Semret (1999), a so-called Progressive …  Lire la suite

Mise en contexte: Le taux de polypectomie est lié à des indicateurs d'assurance qualité de la coloscopie de dépistage. Toutefois, il est difficile d'identifier les coloscopies de dépistage des bases de données de santé provinciaux. Objectif: estimer les taux de polypectomie pour la coloscopie de dépistage en fonction des indications selon le patient et l'endoscopiste et de les comparer aux indicateurs de qualité publiés. Méthodes: Une étude de cohorte rétrospective des endoscopists dans 7 hôpitaux de Montréal et leurs patients âgés de 50-75 qui ont eu subi une coloscopie. Des patients consécutifs ont été interviewés par un assistant de recherche …  Lire la suite

Liu, Xue (Internal/Supervisor)  Lire la suite

The recent listing of the polar bear (Ursus maritimus) as 'threatened' under the United States Endangered Species Act occurred despite widespread debate about the validity of, and need for listing. In this thesis, I conduct a Critical Discourse Analysis on a prevalent discourse in the polar bear debate, that of the Center for Biological Diversity. I aim to denaturalize this discourse by addressing two key questions: How is this polar bear discourse constructed through texts? And, what are the broader discursive practices and sociocultural contexts supporting these texts? I find the Center for Biological Diversity's polar bear discourse is comprised …  Lire la suite

A novel approach whereby one can use probiotic bacteria for the purpose of topical and oral therapy is presented. More specifically, a treatment modality using enzymatically active probiotic production of gaseous nitric oxide (gNO) for wound healing, antimicrobial, cosmetic, and dermatologic therapy is presented. In another aspect, a probiotic treatment modality for metabolic disease and metabolic syndrome using nitrate reductase (NiR) active probiotic bacteria is explored. In concurrence to these requirements, several in-vitro methods are designed and discussed in this report. For some of these studies the use of alginate microcapsules is explored. Results show that probiotic patches can be …  Lire la suite

Fung, Joyce (Supervisor1)  Lire la suite