McGill University Thèses et mémoires par auteur commençant par T

Alzheimer’s disease (AD) is defined by amyloid- plaques and tau neurofibrillary tangles, its two neuropathological hallmarks. Advances in fluid and PET biomarkers over the past decade have fundamentally transformed AD research, enabling direct visualization of amyloid- and tau in living individuals and eliminating the historical reliance on autopsy for definitive diagnosis. This transition has moved the field from a symptom-based framework to one that is becoming increasingly centered on biological mechanisms. This shift has enabled clinical trials to enroll participants with confirmed amyloid pathology and to use molecular readouts, such as amyloid-PET, to verify target engagement. Although these advances have …  Lire la suite

This research focuses on the development, evaluation, and application of a mercury (Hg) mass balance model for predicting the accumulation of Hg in fish. This model requires accurate estimates of Hg elimination rate by fish and feeding rates to adequately predict Hg concentration in fish. An empirical model was developed to estimate Hg elimination by fish using data obtained from published experiments. This analysis showed that Hg elimination rate was overestimated in short-term experiments, positively correlated to water temperature, negatively correlated to body size, and that the elimination rate of inorganic Hg was faster than that of methylmercury. This empirical …  Lire la suite

Since the beginning of this work in 1998, it is estimated that 1780 men died of prostate cancer in Quebec. Molecular analysis of prostate cancer will eventually lead to the discovery of key genes involved in its onset and progression. The present project was to compare gene expression profiles in human non-tumorigenic versus tumorigenic prostate cell lines generated in our laboratory. A putative tumor suppressor gene present on 12q13 would be responsible for the non-tumorigenic phenotype of one cell line as discovered earlier by our team. In order to compare gene expression patterns, expression arrays from Clontech, bearing 588 genes …  Lire la suite

L'agriculture en environnement contrôlé (AEC) est une technique de production intérieure où les conditions de croissance sont soigneusement surveillées et contrôlées pour optimiser la production de cultures. Avec la population mondiale et les changements climatiques qui continuent de progresser, ce type de culture agricole sera un acteur clé pour assurer une plus grande sécurité alimentaire aux générations futures. Cependant, de nombreux projets en lien avec l’AEC sont confrontées à des défis, tant au niveau de la viabilité économique que de l’impact environnemental. Une stratégie pour améliorer l'efficacité en AEC est d'acquérir une compréhension plus profonde de la variabilité des conditions …  Lire la suite

This thesis presents a comprehensive numerical method for determining the current distribution on complex wire antennas. Various individual improvements suggested separately in the literature are extended and developed further, and then are combined with a reformulated junction constraint into an amalgamated whole. Thus: (i) The current is represented with subdomain basis functions such that its derivative (the charge density) is continuous; (ii) POint-matching is replaced by a method named herein "average field matching", This method was developed to extend the application of the finite difference approximation in the derivative term in Pocklington's Equation, such that a large step size can …  Lire la suite

Mackay, H. (Supervisors)  Lire la suite

The impacts and invasion success of non-native aquatic species are expected to change with climate warming, particularly in north temperate regions. Goldfish (Carassius auratus) and Prussian carp (C. gibelio) are non-native species that can rapidly invade and alter inland water ecosystems. The goldfish is already well-established in the Great Lakes, and its abundance is increasing, whereas the Prussian carp has been established in western Canada since at least the mid-2000s and is spreading in Alberta and Saskatchewan; invasions of both these fishes could plausibly be facilitated by warmer temperatures. To understand how climate warming can affect the performance of Carassius …  Lire la suite

This thesis is a study of stable perturbations in convex programming models. Stability of a general model is introduced as lower semicontinuity of the feasible set mapping. This stability is shown to be equivalent to the Robinson notion of stability and regularity. In the convex case, it is also equivalent to the full-rank Slater condition. Then, the relationships between various point-to-set mappings are studied for convex models and new implications between these mappings are established. Also, local and global optimality of parameters is studied. A new result here is a characterization of locally optimal parameters that does not require stable …  Lire la suite

We study stability, optimality and duality theory in convex bilevel programming using a parametric lexicographic programming approach. The results are significantly simplified if the constraints functions have locally flat surfaces.  Lire la suite

The purpose of this paper was to characterize and compare pressure patterns in the skate boot of elite and recreational players during the forward crossover turn. In-skate pressure patterns of eight elite varsity level hockey players (mean +/- SD: height (m) = 1.80 +/- 0.07, weight (kg) = 87 +/- 0.06) and eight recreational hockey players (mean +/- SD: height = 1.76 (m) +/- 0.06, weight (kg) = 82 +/- 0.07) were measured using fifteen piezo-resistive sensors per foot during the forward crossover skating stride. Each participant performed three trials in both the clock-wise (CW) and counter clock-wise (CCW) directions. …  Lire la suite

L'introduction de prédateurs peut avoir de nombreux impacts négatifs sur les populations de proies indigènes; la sévérité de cet impact peut être plus important que celle que peuvent avoir les prédateurs indigènes et peut varier lors de l'introduction de plusieurs prédateurs. J'ai étudié la relation qu'il existe entre les assemblages de poissons indigènes et cinq espèces de prédateurs piscivores introduites à grande échelle: l'achigan à grande bouche Micropterus salmoides, le grand brochet Esox lucius, le crapet de roche Ambloplites rupestris, l'achigan à petite bouche Micropterus dolomieu et le doré jaune Sander vitreus. L'analyse de données provenant de plus de 9000 …  Lire la suite

The 'New Order' government, under President Suharto's leadership, has undertaken different initiatives in the face of both 'political' Islam and 'religious' Islam in Indonesia. Since coming into power in 1966, it has exercised strict control over 'political' Islam; on the other hand, its attitude towards 'religious' Islam has generally been tolerant and even supportive. The result has been a considerable weakening of Islamic political forces but a rapidly developing 'religious' Islam. This reality has forced the present-day generation of Indonesian Muslim thinkers to take an approach which is different from that of the previous generation in responding to the government's …  Lire la suite

The topic of Majorana zero modes has been a focal point of the condensed matter physicscommunity in recent times due in part to their potential applications in quantum computation.Most notably, the exotic exchange statistics of Majorana zero modes form the basis oftopologically protected quantum gates. The physical exchange, or braiding, of Majorana zeromodes is often modeled in two-dimensional systems or by using networks of wires. Recentwork has established that Majorana zero modes can be braided in a purely one-dimensionalsetting with a periodic, or Floquet, drive. Specifically, the work of Bauer et al. in Ref.[1] demonstrates that a working braiding protocol …  Lire la suite

Majorana zero modes (MZMs) appear as edge states in topological superconductors and are envisioned as promising candidates for application towards fault-tolerant quantum computation. Quantum information may be stored in a degenerate ground state subspace constructed from MZMs while quantum gates may be performed by braiding MZMs and exploiting their non-Abelian properties. While the topological protection of MZMs ensures that they are robust against decoherence, their dynamical manipulation can nonetheless induce undesirable transitions to excited states, manifesting as a “diabatic error.”This thesis studies the diabatic error accumulated as MZMs are transported across a superconducting wire, which is an essential building block …  Lire la suite

PINK1 est une kinase essentielle dans la voie de contrôle de qualité mitochondriale (CQM). Elle s’accumule sélectivement sur les mitochondries endommagées et phosphoryle l’ubiquitine (Ub) et le domaine « ubiquitine-like » de Parkin (Ubl), une ligase d’ubiquitine E3. Ces événements recrutent Parkin aux mitochondries endommagées et mènent à son activation. Parkin se met alors à ubiquitiner une variété de substrats mitochondriaux. Une boucle de rétroaction s’établi, avec Parkin fournissant de l’Ub à PINK1 qui par la suite le phosphoryle, activant Parkin de nouveau. Décorées avec de l’Ub et de la phospho-Ub (pUb), les mitochondries endommagées sont isolées pour cesser leur …  Lire la suite

Dans le contexte de la poursuite sans relâche du développement, l'expropriation des terres a alimenté l'agitation sociale croissante au Vietnam et en Chine. Malgré leurs nombreuses similitudes, le Vietnam et la Chine diffèrent fortement dans leur façon de répondre aux pressions et aux demandes sociales. La réponse du Vietnam est plus institutionnalisée, tandis que celle de la Chine, plus réactive. Alors que le Vietnam a adopté des réformes délibérées, programmatiques et globales pour réduire le champ du pouvoir discrétionnaire du gouvernement, la Chine a laissé une plus grande marge de manœuvre aux gouvernements locaux pour exproprier des terres à des …  Lire la suite

The present thesis is concerned with the development of an expert system for the preliminary design of point-to-point HVDC transmission systems, TRANSEPT-DC. This expert system module complements other expert system modules concerned with AC design, insulation coordination, and reliability, all of which form the TRANSEPT family of expert systems for the preliminary design of point-to-point power transmission systems. The domain knowledge of the design of HVDC transmission systems is first discussed. This includes possible HVDC system configurations, cost of terminals, cost of transmission lines, cost of losses, and design expertise. The details of converting the HVDC design domain knowledge into …  Lire la suite

The Cold War, in terms of ideological tensions between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc, carved the world into separate spheres of alignment known as the “First World,” the “Second World,” and the “Third World.” As a historically constructed discourse, the three-world model relies on a paradigm of hierarchical knowledge epitomized by Western modernity and creates a space in which such a model is hegemonic. Resistance to such a worldview is also a prominent component of this paradigm, as evident in the alliances between the socialist states and …  Lire la suite

La synthèse protéique est un processus crucial sous-jacent l'homéostasie cellulaire et la réponse aux stimuli environnementaux. La régulation de la traduction d'ARNm en protéines est compliquée et implique de nombreux points de contrôle. Le premier et le plus important de ceux-ci est l'initiation de la traduction, qui permet de prévenir le gaspillage d'énergie que constituerait l'arrêt de la synthèse protéique à des étapes ultérieures. Parmi les acteurs impliqués dans ce mécanisme, les protéines liant le facteur d'initiation de la traduction eIF4E (4E-BPs) jouent un rôle prépondérant de par leur compétition avec eIF4G pour le même site d'interaction sur la protéine …  Lire la suite

Sod1 encodes a superoxide dismutase, the only type of enzyme that directly converts superoxide into hydrogen peroxide, both of which are reactive oxygen species. In humans, the dysregulation of this enzyme has been associated with many diseases such as amyotrophic lateral sclerosis, heart failure, cancer, diabetes, Down’s syndrome, and Parkinson’s disease. Although germline Sod1 knockout mice (Sod1−/−) displayed an accelerated muscle atrophy with age, a ~30% reduction in lifespan, and an increased incidence of liver cancer, their phenotype is milder than what would have been expected from the central roles played by SOD1. Sod1 is highly conserved between species from …  Lire la suite

The CDP/Cux transcription factor is expressed as a 200 kDa protein that interacts rapidly and transiently with DNA. Proteolytic processing generates a shorter isoform, p110 CDP/Cux, that binds stably to DNA. Processing occurs at the G1/S transition of the cell cycle in normal cells, and constitutively in transformed cells. p110 CDP/Cux stimulates cell proliferation by accelerating entry into S phase. Transgenic mice expressing p110 CDP/Cux are more susceptible to different cancers. CDP/Cux was originally described as a repressor of transcription. My goal was to verify whether CDP/Cux might also participate in transcriptional activation and characterize the molecular basis for transcriptional …  Lire la suite

The primary objective of this study was to identify a daily dosage of oral vitamin D for optimal vitamin D status and growth in infants. Breastfed infants (n=32) were randomized to 400, 800, 1200 or 1600 IU/day of vitamin D3 beginning at one month of age. Blood samples collected at baseline, 4 and 8 weeks thereafter were analyzed for serum 25 (OH) D, parathyroid hormone, alkaline phosphatase, and total and ionized calcium. Growth was assessed by anthropometry and bone mineral content and density by dual-energy x-ray absorptiometry. Infants showed normal growth throughout the study. Significant increases in 25(OH) D were …  Lire la suite

This thesis is concerned with the role that consumer demand for news plays in political behaviour. While a great deal of study has been done to examine media supply, very little has looked into the other side of the equation. If we are interested in the distortions media creates, than part of that equation must be a concern with what types of news individuals select -- particularly in the 21st century context of a "high-choice" media-environment. I examine this problem through a new experimental method designed to overcome shortcomings in the existing research. Previous studies have focused their methodologies primarily …  Lire la suite

Canada has seen an uneven temporal and geographical decline in homicide rates since the mid 1970s. In addition, Canada has simultaneously seen a proportionate increase in unsolved homicides. These two trends at first appear incongruent; however, there are a multitude of factors which influence both homicide rate fluctuations and declining clearance rates. This dissertation examines these two separate yet related phenomena in three manuscripts. In the first manuscript homicide clearance is examined at the case level in order to discern which event level features have the strongest affect on clearance outcomes. It compares the differential effects of geo-temporal influences, victim …  Lire la suite

Vigano, Antonio (Supervisor1)  Lire la suite

Cystic Fibrosis transmembrane conductance regulator (CFTR) Cl - channels are rapidly and efficiently deactivated by a type 2C serine/threonine phosphatase (PP2C). The efficiency of this regulation suggests that PP2C and CFTR are associated within a regulatory complex. Previous work has shown that PP2C and CFTR can be co-immunoprecipitated and reversibly coupled by exposing cell lysates to the hydrophilic cross-linker dithiobis [sulfosuccinimidyl proprionate]. While it is clear that PP2C can associate with CFTR, the nature of the interaction between them has not been defined. The goal of this study was to identify specific region(s) within CFTR that mediate this interaction. The …  Lire la suite

Nos sens travaillent de paire avec nos fonctions motrices afin de nous permettre d’interagir avec notre environnent. Cette interaction est communément appelée intégration sensorimotrice. La recherche en intégration sensorimotrice investigue les réponses motrices aux stimulis visuels et auditifs. Plus particulièrement, dans les études d’intégration audio-motrice, les participants chez qui le développement est typique (TD) ont tapé suivant des battements de vitesse et de complexité métrique variable afin d’évaluer une forme spécifique d’intégration aussi appelée synchronisation. Chez les patients diagnostiqués de trouble du spectre de l’autisme (TSA), l’intégration sensorimotrice montre des déficits dans les tâches visuo-motrices et audio-motrices. Malgré que de …  Lire la suite

Dans cette thèse, la théorie de l’inertie de l’élément de pale (TIEP) est utilisée pourmodéliser le rotor-propulseur de petits aéronefs téléguidés dans le but de prédire la pousséeproduite par cette configuration de rotor. Afin de pouvoir utiliser le modèle TIEP, les propriétés géométriques et aérodynamiques du rotor sont obtenues en tranchant les pales depropulsion en plusieurs coupes. La méthode décrite dans cette thèse permet d’extraire lacorde, l’angle de pas et les coordonnées de surface portante. Ces coordonnées permettentde simuler l’incidence de portance nulle et le coefficient de trainée à l’aide du logicielXFOIL du MIT. Des expériences ont été menées pour …  Lire la suite

This research project is situated in the Greek context, one defined by the continuous diversification of Greek society and the rise of extreme right political groups. Drawing from the theoretical frameworks of a critical approach to diversity, the disciplinary approach to history, the principles of historical thinking, and Ross Dunn's three models of world history, this study compares two sets of textbooks: the 1980 and 2015 grades six, nine, and twelve Greek textbooks of modern history. The three research questions of this study trace the development of the textbooks' epistemological stance, their thematic focus, and the narratives of non-Western peoples. …  Lire la suite

Une méthode de génération de signaux analogiques qui est appropriée pour la plupart des méthodes de test digitale comme décrit par le standard de test IEEE 1149.1 est présentée. Cette méthode peut être utilisée pour produire une série de signaux encodés dans la phase et la fréquence à des fins de tests tel que « system test debug » et « system test diagnosis ». La méthode consiste à produire un signal périodique digitale consistant d'une seule valeur binaire à l'aide d'un module « software » externe au circuit intégré et de le décoder dans le circuit intégré à l'aide …  Lire la suite

Les cancers du sein triple négatifs (CSTN) sont les plus agressifs et les plus mortels parmi tous les sous-types moléculaires du cancer du sein. Les patientes atteintes de CSTN disposent de peu d’options de traitement et leur état de santé est le plus souvent cliniquement défavorable. À ce jour, il n'existe ni traitements approuvés ni thérapies ciblées efficaces contre le CSTN, soulignant un besoin médical clairement identifié et non satisfait pour ces tumeurs possiblement léthales. Notre laboratoire a précédemment montré que l'inhibition de l'expression ou de l'activité du gène de la kinase dépendante des cyclines 4/6 (CDK4/6), en utilisant un …  Lire la suite

Based on a critical review of North American odour regulations, it was concluded that current statutory nuisance laws and threshold principles do not meet the requirements of an effective regulatory strategy. An Odour Impact Model (OIM) developed previously helps to solve this deficiency by incorporating the effects of odour hedonics into odour impact assessments. This investigation fit a mathematical expression to the OIM dose-response curves of six pure odorants. A natural extension of this led to the development of the Odour Impact Dispersion Model (OIDM). This model merges the OIM's dose-response profiles with atmospheric dispersion modelling to predict and map …  Lire la suite

This study tests the validity of Holland's (1985a) principles regarding the parent-offspring vocational type agreement in immigrant families. Moreover, it examines and compares the influence of parental ethnicity, SES and level of education on the parental-offspring type agreement in immigrant and non-immigrant families. Finally, it explores the role of child's gender on the parent-offspring type agreement. Data were collected through the administration of (1) The Vocational Preference Inventory (VPI, revised) (Holland, 1985b), and (2) The Personal Data Questionnaire (PDQ) (developed by the researcher) to high school and college students. The immigrant sample consisted of 100 Canadian-born children of Greek-born immigrants …  Lire la suite

McLelland, Dr. Joseph C.  Lire la suite

The study compared competence satisfaction in a ball striking activity, as measured by risk taking and achievement, of individuals with ( N = 16) and without (N = 18) physical disabilities under mastery and performance orientation climates. The students ranged in age from 7-13 years. They were required to strike a ball into nets of three different size-distance combinations. Results supported the first hypothesis of no competence satisfaction differences between the groups under mastery and performance climates. The second hypothesis that the introduction of performance climate would increase risk taking and this would affect achievement accomplishments and competence satisfaction was …  Lire la suite

Steroid hydroxylase activities detected in the rat adrenal preincubation medium (PIM) were located exclusively in the subcellular particulates. The characteristic accumulation of 11-beta-hydroxyprogesterone when 14-C-progesterone was incubated at 37ºC with the PIN obtained from incubations at 37ºC could be reproduced with a dilute homogenate of rat adrenals (2.4 mg/4 ml), and was related to a higher susceptibility of 21-hydroxylase to denaturation, relative to that of ll-beta-hydroxylase. This last conclusion was reached from the observations that: (a) Preincubation of tissue et 0ºC - rather than at 37ºC - followed by incubation of the media at 37ºC led to an increased formation …  Lire la suite

The biosynthesis of adrenocortical steroids has been intensively studied in the last decade or so. Comprehensive reviews have appeared covering multiple aspects of the processes involved in the elaboration of the cortical secretory products under various experimental conditions (1, 2, 3, 3a). [...]  Lire la suite

Isolated bovine adrenal cortical mitochondria (BACM) possess distinctly different transport properties From mitochondria of other tissues. BACM show little citrate uptake in the absence of a specific dicarboxylate, the stimulation is in the order of succinate >= fumarate > malate. Unlike other systems, succinate and malate are transported by two discrete transport systems. BACM stored as long as seven days, and the inner membrane-matrix preparation of BACM retain full and characteristic transport properties of the freshly prepared BACM. The latter observation shows directly that the inner membrane is the only barrier to transport of carboxylates of BACM. The inhibition of …  Lire la suite

Copy number of a copia-like retrotransposon was compared in self- and cross-fertilizing taxa of the annual plant genus, Amsinckia. It was hypothesized that variation in copy number between populations with contrasting mating systems could be used to interpret the relative importance of factors influencing copy number (purging of element-induced mutations, ectopic exchange, and the level of heterozygosity). Populations of Amsinckia spectabilis var. microcarpa and A. furcata, two outcrossing taxa, and their self-fertilizing relatives, A. spectabilis var. spectabilis and A. vernicosa were studied. Probes for Southern hybridisation were generated for each respective taxa through the amplification of a conserved region of …  Lire la suite