McGill University Thèses et mémoires par auteur commençant par Y

La nétrine-1, une molécule de guidage axonale, et ses récepteurs, DCC et UNC5H, contribuent à l'organisation et à la fonction des circuit dopaminergiques mésocorticolimbiques pendant le développement cérébral. Fait intéressant, la nétrine-1 et ses récepteurs continuent à s'exprimer dans les régions du corps cellulaire et des terminaisons nerveuses de la dopamine mésocorticolimbique tout au long de la vie, malgré un changement radical du ratio de l'expression des récepteurs DCC:UNC5H par les neurones de la dopamine mésocorticolimbique dans l'aire tegmentale ventrale (ATV), la région somato-dendritique de la dopamine mésocorticolimbique, à l'adolescence. Ceci suggère que la signalisation induite par la nétrine-1 est …  Lire la suite

Repeated exposure to amphetamine (AMPH) induces sensitization to its behavioral-activating effects. The development of sensitization depends on (1) the direct actions of AMPH in the ventral tegmental area (VTA), the cell body region of the mesocorticolimbic DA system, and (2) AMPH-induced glutamatergic neurotransmission in this region. Moreover, sensitization is accompanied by morphological changes in mesocorticolimbic DA circuitry. During development, the DA system is organized, at least in part, by the netrin-1 family of guidance cues. Both netrin-1 and its DCC and UNC-5 receptors continue to be expressed in the mesocorticolimbic DA system of the adult brain. Importantly, netrin-1 receptor deficient …  Lire la suite

Greer, Charles William (Supervisor2)  Lire la suite

Les déchets organiques municipaux transformés en engrais organiques peuvent remplacer les engrais minéraux pour soutenir la production agricole et le stock de carbone organique du sol (COS), mais peuvent induire des émissions de gaz à effet de serre (GES) du sol, selon les propriétés physicochimiques des engrais organiques. Ce projet a évalué l’effet de trois engrais organiques sur les rendements du maïs (Zea mays L.) et du soja (Glycine max L.), du stock de COS (0 à 20 cm) et des flux de GES du sol. Les engrais organiques étaient les déchets alimentaires compostés (compost; 240 kg N/ha), lisier biosolides …  Lire la suite

Crepeau, Claude (Supervisor)  Lire la suite

Schwartzman, Kevin (Internal/Cosupervisor2)  Lire la suite

Candida glabrata is an emerging opportunistic fungal pathogen which is the overall second leading contributor after Candida albicans in all candidiasis infections, especially in patients with compromised immune systems, such as patients who suffer from AIDS or have received organ transplants. This study focuses on the transcription factor activity of zinc cluster proteins, which are found only in fungi, and their relationship to antifungal resistance. In contrast to Saccharomyces cerevisiae and to some extent C. albicans, the role and mechanisms of zinc cluster proteins in drug resistance in C. glabrata has not been as thoroughly investigated in depth in the …  Lire la suite

Je propose une analyse contextuelle des relations entre les tribunaux britanniques et la Cour européenne des droits de l'homme par rapport à l'interprétation des droits de la Convention européenne des droits de l'homme. Le cadre de révision de la constitution d'Aileen Kavanagh et le modèle constitutionnel du Commonwealth de Stephen Gardbaum servent de base à mon cadre théorique pour analyser la relation entre le pouvoir judiciaire britannique avec le « Human Rights Act » de 1998 et la Cour européenne des droits de l'homme. Plus précisément, j'évalue les obligations et les pouvoirs de contrôle constitutionnel conférés au pouvoir judiciaire par …  Lire la suite

With South Korea as the case study, this thesis analyzes the role, allocation, and productivity of foreign capital. We evaluate hypotheses based on the Harrod-Domar, Solow-Swan, and dual-gap growth models with foreign savings. An econometric growth-with-foreign debt model (consisting of forty three equations) is estimated to test hypotheses and to quantify theoretical conclusions. The econometrics include tests of (a) the Griffin-Enos substitution hypothesis, and (b) the Please hypothesis or effect. We also include South Korea's internal and external economic adjustments in response to the oil-with-recessionary shocks in 1974-1975, and 1979-1980. The econometric model is tested to ensure that its dynamic …  Lire la suite

Wheat (Triticum spp.) is the third most produced cereal crop, being planted on more than one sixth of global cultivated farmlands, and providing 40% of world grain production. Numerous biotic and abiotic challenges can limit its production. Mycorrhizal-colonization of roots is a promising approach for mitigating stresses, has been studied in different plants (ex. rice, pepper, citrus, etc.) and has proven to be beneficial in aspects such as: increasing water absorption, enhancing mineral uptake and improving abiotic stress tolerance. Studies on this mutualistic relationship have been limited in wheat and information regarding alternation of antioxidant capacity of various wheat grain …  Lire la suite

Current visualization methods for large volume angiograms share the difficulty of having to display depth information using conventional two-dimensional screens, while static viewing conditions between two consecutive rotations are often required. This thesis presents new directions towards the interactive display of and navigation through cerebral vessel networks. To reduce the computational load and storage requirements; a method is developed to extract a centerline representation of the vessel network from volume images. Shape attributes such as the position of the center point as well as the cross-sectional size, tangent, curvature, torsion and bifurcation of the vessel, are either contained in the …  Lire la suite

The relationship between the Arctic and sub-Arctic sea-ice concentration (SIC) anomalies, particularly those associated with the Greenland and Labrador Seas' "Ice and Salinity Anomalies (ISAs)" occurring during the 1960s/1970s, 1970s/1980s, and 1980s/1990s, and the overlying atmospheric circulation (SLP) fluctuations is investigated using the Empirical Orthogonal Function (EOF) and Singular Value Decomposition (SVD) analysis methods. The data used are monthly SIC and SLP anomalies, which cover the Northern Hemisphere north of 450 and extend over the 38-year period 1954--1991. One goal of the thesis is to describe the spatial and temporal variability of SIC and atmospheric circulation on interannual and decadal …  Lire la suite

Conventional displacement-based finite element programs do not yield unique values of stress components which ought to be continuous at element interfaces. The errors, being the differences from the correct unique values, become unacceptably large at a bimaterial interface when the moduli of the two materials are significantly different. This thesis formulates and implements new finite elements for obtaining the correct values of the stress components, both continuous and discontinuous ones, at bimaterial interface points under general dynamic loading, assuming linear, isotropic, elastic material behaviour. The constructed finite elements programs, suitable for analyzing two-dimensional and axisymmetric three-dimensional problems, have been validated …  Lire la suite

Text categorization (TC) is the task of automatically categorizing textual digital documents into pre-set categories by analyzing their contents. The purpose of this study is to develop an effective TC model to resolve the difficulty of automatic classification. In this study, two primary goals are intended. First, a Hidden Markov Model (HAM is proposed as a relatively new method for text categorization. HMM has been applied to a wide range of applications in text processing such as text segmentation and event tracking, information retrieval, and information extraction. Few, however, have applied HMM to TC. Second, the Library of Congress Classification …  Lire la suite

The goal of Speech Understanding Systems (SUS) is to extract meanings from a sequence of hypothetical words generated by a speech recognizer. Recently SUSs tend to rely on robust matchers to perform this task. This thesis describes a new method using classification trees acting as a robust matcher for speech understanding. Classification trees are used as a learning method to learn rules automatically from training data. This thesis investigates uses of classification trees in speech system and some general algorithms applied on classification trees. The linguistic approach requires more human time because of the overhead associated with handling a large …  Lire la suite

The androgen receptor (AR) serves as a key driver of the proliferation and survival of prostate cancer (PCa) cells. Current mainstay treatment is to block the AR signaling by androgen deprivation therapy and antiandrogens. Despite the short-term efficacy of suppressing AR signaling, the tumor eventually adapts resistance via constitutive activation of the AR axis and manifests in the form of castration-resistant prostate cancer (CRPC). So far, multiple molecular mechanisms behind castration-resistance have been reported, including persisted androgen synthesis, AR amplification, AR point mutation, AR splice variants and AR transcriptional co-regulators. Unfortunately, current AR-targeting agents are unable to prevent AR reactivation, …  Lire la suite

Le cancer de la prostate résistant à la castration (CRPC) est une forme récidivante du cancer de la prostate des thérapies initiales de privation d'androgènes (ADT), sa progression manifeste une activité de signalisation des récepteurs aux androgènes (AR) réactivée malgré le niveau de castration des androgènes. Lorsque le CPRC se développe, l'ADT de deuxième ligne est proposé aux patients pour rétablir le blocage de la signalisation AR, y compris l'abiratérone (Abi), inhibiteur de la biosynthèse des androgènes ; et les anti-androgènes, tels que l'enzalutamide (ENZ), qui entrent en compétition pour la poche de liaison aux androgènes dans le domaine de …  Lire la suite

A beta-galactosidase gene from Bifidobacterium breve B24 which showed the higher hydrolytic and synthetic activity was cloned in E. coli. The complete beta-galactosidase gene contained 2076 bp nucleotides and encoded 691 amino acids which had a high homology to the other Bifidobacterium species. This beta-galactosidase was homologous to that of the LacA family. The galA gene was successfully over-expressed in E. coli ER2566. To observe any change in the recombinant enzyme, beta-galactosidases from Bifidobacterium breve B24 and recombinant E. coli ER2566 were purified to homogeneity by ion exchange chromatography (Mono-Q) and gel-filtration chromatography (Superose-12 and Superdex 200) columns. The molecular …  Lire la suite

Chang, Xiao-Wen (Supervisor2)  Lire la suite

A fundamental study on the behaviour of flotation column froths is presented. Three main aspects were considered: hydrodynamic, cleaning (rejection of hydraulically entrained particles) and selectivity (separation between particles of different hydrophobicity). Column froth hydrodynamics were studied in a two phase (gas-liquid) system. A model to estimate gas holdup from electrical conductivity was developed. Bubble coalescence was evaluated by means of local measurement of gas holdup and bubble size distribution, consequently bubble surface loss along the froth was determined. Mathematical models are developed to describe liquid entrainment and drainage throughout the froth. The cleaning action was evaluated by monitoring feed …  Lire la suite

This thesis examines the moral, ethical and legal aspects of reproductive human cloning. After examining the facts about cloning, this thesis tackles the difficult question of whether humans should be cloned. This is explored through an in-depth analysis of the moral and ethical acceptability of human cloning. The author concludes that human cloning should never be attempted and that consequently such a practice should be permanently prohibited by a legal norm. This thesis then surveys national legislation and international law to see if there presently exists a prohibition of human cloning. This thesis then examines possible future legal action regarding …  Lire la suite

This thesis presents the design and implementation of a Vital Signs Monitoring System for a Patient Data Management System in an intensive care unit. The Vital Signs Monitoring System provides graphical display of patient data to assist medical decision making. It performs real-time patient data acquisition, and supports data management. Visual coding of information has been investigated to ensure effective graphical representation of patient data, to reduce screen clutter, and to enhance interpretability of graphical displays. A survey of existing patient monitoring systems, and patient data management systems is presented to give an overview of the recent advancements in these …  Lire la suite

Animals can associate orosensory characteristics from food with postingestive effects and adjust meal size to prevent energy deficit. By using odor-fasting duration conditioning, two studies were conducted to test the above hypothesis. In the first study, thirteen male and eleven female adult Wistar rats were given 1.5 hours to ingest a casein-based test-meal odorized by either vanilla or chicken flavor prior to a 4-hour short-fast or a 12-hour long-fast. Rats went through the training phase with a pseudo-random sequence of six duplicates of each odor-fasting pairing over four experimental days, followed by an odor preference test. Gender differences may exist …  Lire la suite

RÉSUMÉCette thèse explore les niveaux variables d’engagement dans l’internationalisme ouvrier parmi les syndicats industriels turcs au cours des deux dernières décennies. Elle cherche à comprendre pourquoi certains syndicats sont plus enclins à développer des stratégies et des pratiques transnationales que les autres, malgré les bénéfices mesurables d’établir des partenariats internationaux—en particulier à travers les relations avec les fédérations syndicales mondiales (FSM). En compliquant les explications conventionnelles qui attribuent ces divergences aux orientations idéologiques ou aux caractéristiques sectorielles, j’argue que ces variations proviennent de différentes formes d’isomorphisme organisationnel, notamment l’isomorphisme normatif tel que défini par Paul J. DiMaggio et Walter W. …  Lire la suite

Turgay, A. Uner (Internal/Supervisor)  Lire la suite

Carlo, Santaguida, (Supervisor2)  Lire la suite

Diaphragmatic myotubes are known to constitutively express CCR1, a chemokine receptor in the C-C chemokine family, when cultured in vitro. It has been shown that CCR1 and its ligand CCL3 (MIP-1α) are directly involved in muscle repair responses in vitro. Furthermore, in vivo experiments, carried out in the MDX mouse model of muscular dystrophy, showed that these molecules were up-regulated in the dystrophic diaphragm muscle thus suggesting a role for CCR1 in inflammation and muscle healing. In this study, indeed, the role of CCR1 was investigated, with focus on inflammatory cell infiltration within the injured muscle using the freeze injury …  Lire la suite

Bajcsy, Jan (Supervisor)  Lire la suite

Operating power tools over extended periods of time can pose significant risks to humans, due to the strong forces and vibrations they impart to the limbs. Telemanipulation systems can be employed to minimize these risks, but may impede effective task performance due to the reduced sensory cues they typically convey. To address this shortcoming, we explore the benefits of introducing simple vibrotactile cues, in addition to auditory and low-level force feedback, on users' performance in a VR mechanical assembly task employing a simulated impact wrench. The vibrotactile effects rendered in this study represent not only collision states, but also simplified …  Lire la suite

Les aérosols atmosphériques sont des suspensions de minuscules particules dont le diamètre varie de 0.001 à 10 μm dans l'air. Ils sont normalement composés d'eau, de matériaux inorganiques, notamment d'ions, et de composés organiques provenant de sources naturelles et anthropiques par le biais de processus primaires et secondaires. Les particules d'aérosols anthropiques sont produites par des activités humaines comme la combustion de combustibles fossiles et les polluants industriels. Les océans, la végétation, les sols et les déserts sont des sources importantes d'aérosols naturels. Bien que petits, les aérosols peuvent avoir un impact important sur le climat de la Terre et …  Lire la suite

Cette dissertation traite de différents aspects reliés à la reconstruction d'objets en 3D à partir d'images provenant de plusieurs caméras dans un environnement immersif de projection vidéo. Un des aspects est la correction des couleurs servant à compenser les différences entre caméras et projecteurs. Plusieurs méthodes sont analysées et une approche basée sur les réseaux neuronaux est proposée comme solution. Le probléme des régions cachées ou uniformes sur la construction des cartes de profondeur est aussi considéré. Comme amélioration, l'information de profondeur est propagée à l'aide de traitement non linéaire de diffusion basé sur des contraintes de gradient d'image. Contrairement …  Lire la suite

This thesis is concerned with development and implementation of an efficient and numerically reliable positioning algorithm based on the combination of code pseudorange (C/A) and carrier phase (L1) measurements with cycle slip detection. In GPS a typical technique for kinematic position estimation is relative positioning where two receivers are used, one receiver is stationary and its exact position is known, the other is roving and its position is to be estimated. We describe the physical situation and give the mathematical model based on the difference of the measurements at the stationary and roving receivers. The model we consider combines both …  Lire la suite

L'objectif de cette thèse est de développer des techniques de modélisation statistique pour caractériser la variabilité phonétique dans la reconnaissance automatique de la parole (RAP). Un problème adressé est la détection fiable des erreurs de prononciation, à l'échelle du phonème, dans des énoncés provenant d'applications de thérapie de la parole. Cette thèse inclut également une étude de l'habilitée des systèmes de reconnaissance à modéliser la variabilité phonétique présente dans les applications indépendantes du locuteur. Ces deux problèmes sont traités comme des occurrences du même problème fondamental qu'est la modélisation robuste de la variabilité phonétique dans la RAP.Les contributions techniques de …  Lire la suite

Nazhat, Showan (Supervisor1)  Lire la suite

La prédiction des propriétés thermodynamiques et des équilibres de phase d'un système d'oxyde peut jouer un rôle important dans le développement et la compréhension des procédés métallurgiques, céramiques et géologiques. Les bases de données thermodynamiques, développées par une évaluation critique et une optimisation de toutes les propriétés thermodynamiques existantes et diagramme de phase, peuvent aider à mieux comprendre le mécanisme de réaction dans divers procédés industriels et à développer de nouvelles technologies pour diverses industries.Dans le cadre d'un grand développement de la base de données thermodynamique pour les applications de fabrication du verre, toutes les phases solides et liquides du …  Lire la suite

Chen, Linan (Internal/Cosupervisor2)  Lire la suite

We study in this thesis the Characteristic Mapping (CM) framework and its application in various scientific computing problems involving transported quantities. The CM framework is a novel numerical approach for general transport equations; it consists in discretizing the deformation map generated by the transport flow instead of the transported quantities themselves. This computation yields the solution operator of the advection equation, called the characteristic map, which can then be used to transport any quantity evolving under the same transport flow. The CM method is distinguished by several unique numerical properties made possible by its geometric approach: any number of transported …  Lire la suite

This thesis presents a survey of the development of economic growth theory, including the latest developments in the relationship between international economic integration through international flows of goods and/or knowledge and endogenous economic growth. Based on the following literature review, a new and more reasonable model for the research and development (i.e., the R&D) sector--a sector which is considered the source of long-run growth--is offered in order to develop and improve the framework built by Rivera-Batiz and Rome (1991), i.e. the RBR model. This new model will make the RBR framework more complete and rational. In this new model, it …  Lire la suite

This PhD. dissertation consists of three essays to fill some gaps in the recent research in international trade and endogenous growth theory. The first essay explores the dynamic effect of interaction of research and development (R&D) activities among countries on endogenous economic growth. It attempts to fill the gap between the current endogenous growth research focused on independent R&D activities and decision-making in the international competition and the interdependent R&D competition in reality. This paper finds that the growth rates, welfare, and investment on R&D in the world do differ between independent R&D activity and interdependent R&D activities among countries. …  Lire la suite

Aluminum gallium nitride (AlGaN) ultraviolet (UV) laser diodes (LDs) are of great research interest due to their wide range of applications and promising future to replace today’s dominant UV lasing technologies, such as gas lasers and solid-state lasers. Nonetheless, the majority of the studies on AlGaN deep UV lasers are still on optical pumping and the development of electrically driven counterparts is relatively slow, mainly rooted in the difficulties in achieving high quality AlGaN epilayers and insufficient p-type conduction. In addition, the AlGaN UV laser research predominantly relies on the structures grown by metalorganic chemical vapor deposition (MOCVD) and the …  Lire la suite

De nombreux matériaux biologiques durs, tels que les coquillages et les os, sont des biocéramiques résistantes qui ont des combinaisons uniques et attrayantes de rigidité, de résistance et de ténacité. Ces matériaux biologiques sont constitués de constituants fragiles et d'interfaces organiques faibles mais atteignent des amplitudes de ténacité bien plus élevées que leur consituants. Les performances exceptionnelles des matériaux biologiques durs proviennent de leur microarchitecture complexe, organisée sur plusieurs échelles de longueur. La taille, la forme et la disposition des blocs de construction rigides dans ces matériaux déclenchent de nombreux mécanismes de durcissement tels que le glissement aux interfaces et …  Lire la suite

Les réseaux neuraux convolutifs (RNC) ont permis des améliorations importantes dans le do-maine de la vision artificielle grâce à une percée dans le domaine de l’apprentissage profond.Avec l’apparition récente de RNC plus profonds, plus larges et plus complexes, la configura-tion manuelle de ces réseaux devient une tâche difficile, en particulier lorsque l’optimisationdoit prendre en compte la performance machine.L’optimisation séquentielle par modèles (Sequential model-based optimization, SMBO)est une technique efficace pour l’optimisation d’hyper-paramètres dans des algorithmes d’ap-prentissage machine (AM) ayant de nombreux paramètres. Elle permet de trouver de bonnesconfigurations avec un nombre relativement bas d’évaluations à l’aide d’un modèle régressifpour prédire la …  Lire la suite

Angeles, Jorge (Internal/Supervisor)  Lire la suite

Les fragments de code (petite portion réutilisable de code source) sont d'importantes ressources afin de comprendre les interfaces de programmation (API) de bibliothèques logicielles. Dans plusieurs scénarios d'utilisation de fragments de code, ils doivent être réduient à l'essentiel. Par exemple, lorsqu'il servent d'indices pour de plus longs programmes, afin de rappeler aux développeurs des idiomes qu'ils connaissent déjà ou encore pour afficher des résultats de recherche. Cette dissertation fait un compte-rendu de la recherche sur la réduction, ou la synthèse, des fragments de code, et apporte trois principales contributions : L'étude de cas sur la génération de résumé de fragments …  Lire la suite

Xinyu Liu (Supervisor1)  Lire la suite

Les troubles comportementaux de navigation spatiale et d'intégration de chemin sont des marqueurs fiables du déclin pathologique au cours des premiers stades de la maladie d'Alzheimer (MA). Pour étudier les opérations du circuit neuronal qui peuvent causer ces déficits de navigation, nous avons effectué des enregistrements électrophysiologiques de neurones accordés spatialement dans le cortex entorhinal médian (MEC) et la région CA1 de l'hippocampe dans le modèle de souris transgénique amyloïde bêta (Aβ) J20. Les cellules de grille entorhinale ont montré une perturbation de la périodicité spatiale, de la stabilité spatiale et de la synchronie avec les interneurones et les cellules …  Lire la suite

In this thesis we use a novel refinement-based technique to formally verify data transfer in an asynchronous timing framework. Novel data transfer models are proposed to represent the implicit relationship between clock and data validity events. We construct comprehensive implementation models for a previously published GALS architecture for on-chip systems [MVK+99]. Applying our techniques on this claimed to be hazard-free architecture, we find several hazards, and other dangers, together with additional delay constraints to avoid some of the detected dangers. We further exam re-design issues of an existing GALS system as compact design, internal structure optimization and reduced power consumption. …  Lire la suite