McGill University Thèses et mémoires par auteur commençant par N

L'épiderme est un épithélium stratifié qui joue un rôle essentiel de barrière protectrice. Par une différenciation en plusieurs étapes, les cellules souches basales et prolifératives remplacent continuellement les cellules de la surface de la peau qui se désquament. Il a été démontré que la voie de signalisation Notch régule la différenciation précoce des cellules basales, mais les ligands spécifiques et les cellules dans lesquels ils sont exprimés restent mal connus. Les données préliminaires de séquençage d'ARN à cellule unique suggèrent que le ligand Notch Jag2 est exprimé principalement dans les cellules souches de l’épiderme. Pour étudier le rôle de Jag2 …  Read more

Wood, Elizabeth (Advisor)  Read more

Formal and cultural analyses of The Wizard of Oz (Victor Fleming, 1939) indicate that Dorothy's passage from Kansas, through Oz and back to Kansas symbolically recapitulates paradigmatic stories of both America (the nation's passage from utopian origin, through history, to utopian destiny) and Christianity (the cosmic passage from paradisian origin, through history, to paradisian destiny). In order to "go home" (the explicit theme), Dorothy must "grow up" (the implicit theme); this link is also paralleled symbolically at both national and cosmic levels. Resonating profoundly with the collective ethos, this movie has come to function in a modern (ostensibly secular) society …  Read more

Contexte : L'enseignement de la neurochirurgie a été facilité ces dernières années par des simulateurs chirurgicaux en réalité virtuelle, qui offrent un environnement de formation sûr aux stagiaires. L'électroencéphalographie (EEG) a été utilisée pour évaluer l'activité électrique du cerveau pendant la performance chirurgicale. Lorsqu'elles sont divisées en différentes bandes de fréquences, les données EEG se prêtent bien à l'analyse par apprentissage automatique, une branche de l'intelligence artificielle. Bien que la classification de l'apprentissage automatique soit traditionnellement difficile à interpréter, les progrès des techniques d'interprétabilité des modèles, telles que celles utilisant les valeurs de Shapley, permettent de déterminer l'importance de chaque …  Read more

Les hélicoptères volent à des altitudes relativement basses susceptibles à la formation de glace sur les composantes portantes. Ce cumul peut entraîner une augmentation du poids et une dégradation des performances du rotor qui soit obligent les pilotes à atterrir ou, pire, peuvent causer des accidents. En raison du coût élevé des campagnes de certification pour vol en mode givrant, rares sont les hélicoptères certifiés pour de tels vols. La simulation numérique du givrage en vol est capable de réduire les coûts en remplaçant efficacement certains essais physiques et en vol.Au cours des deux dernières décennies, la simulation numérique du …  Read more

Au Canada, les Inuits sont confrontés à une transition nutritionnelle rapide loin de la consommation d'aliments traditionnels (TF) qui coïncide avec une prévalence plus élevée de l'obésité, du diabète de type 2 (DM2) et un statut inférieur de vitamine D. Le statut en vitamine D est inversement associé à des risques de développement du prédiabète, du syndrome métabolique (METS) ainsi que le DM2. Cette thèse est composée de 4 études utilisant des données des adultes inuits (≥18 ans) qui ont participé à l'enquête transversale de 2007-2008: International Polar Year Inuit Health Survey; menée dans trois régions arctiques: Nunavut, Nunatsiavut et …  Read more

Jean-Baptiste Boyer d'Argens, a dissident and libertine writer, has played an important role by spreading Enlightenment ideas to Frederic II of Prussia. He began to write in the 1730s, a particularly productive and innovative period. His work is a testimony of the profound transformation of the novel toward the modern approach. By blending different formal genres (novel and memoirs), he made use of an hybrid genre in which moral truth is greater than historical accuracy. His entire repertoire converges toward a principal theme, the emancipation of man. This notion of freedom not only implies to the freedom of thought, conduct …  Read more

Particle tracking is an optical microscopy based technique that can probe very small changes in the dynamics of microscopic objects. However, the information required to make use of this powerful tool is widely scattered in the scientific literature. The purpose of my thesis is to develop a comprehensive approach for single-particle tracking applied to the lateral diffusion of synaptic receptors. This thesis will describe the proper use of particle tracking including the description of how particle tracking algorithms are able to extract trajectories of particles from a set of consecutive digital time series images. Second, several methods to extract coefficients …  Read more

Brynen, Rex J. (Internal/Supervisor)  Read more

Requirements for the development of sustainable farm systems include the generation of site-specific management practices and heightened levels of awareness and empowerment within the farming community. The current model of technology development and transfer does not adequately facilitate the development of these characteristics. This study elaborates an alternative, participatory approach for agricultural extension, and presents the experiences of a group consisting of six farmers and a university co-research team, who employed this approach over a 17-month period to develop more ecologically sustainable farm systems. The stages of a "process of development model" are: General Systems Description, Convergence, Implementation, Exchange, and …  Read more

Le sommeil est un aspect très important, bien que encore peu compris, de la physiologie humaine. Chez l'homme, le sommeil est subdivisé en plusieurs stades de sommeil physiologiquement distincts. La détermination et l'étiquetage précis des stades du sommeil à partir des enregistrements d'EEG sont fondamentaux dans la recherche et la pratique clinique du sommeil. Cette thèse propose unenouvelle architecture neurale profonde pour l'étiquetage automatisé des stades du sommeil à partir de l'EEG. L'architecture utilise une nouvelle technique, des réseaux neuronaux convolutionnels avec des spectrogrammes de données EEG comme entrée, qui ne dépend pas de caractéristiques d'experts ni de prétraitement informé …  Read more

Plusieurs facteurs génétiques et environnementaux ont été liés au trouble du déficit de l'attention avec ou sans hyperactivité (TDAH). Cependant, une caractérisation plus approfondie concernant certains facteurs de risque causatifs est nécessaire. La thèse suivante démontrerait une analyse visée à identifier le rôle d'un polymorphisme dans le gène récepteur dopamine 4 (DRD4) chez les enfants atteints du TDAH. Premièrement, une révision compréhensive des études génétiques, fonctionnelles et comportementales sur DRD4 et le TDAH est présentée. Ensuite, nous avons performé deux analyses pour déterminer le rôle de DRD4 dans l'étiologie du TDAH. Dans notre première étude pharmacodynamique, nous avons examiné la …  Read more

The purpose of this investigation has been to examine the literature on manganese deposits of Canada and to find out what the mode of occurrence of these deposits suggests as to origin. By the study of all of the deposits certain relationships have been indicated by their geographical and geological distribution and their mineralogy. The deposits of Nova Scotia and New Brunswick have been the most fruitful in this respect. The economic possibilities of the manganese occurrences have been investigated.  Read more

This thesis examines the reasons why Walt Whitman has been a "puzzle" to literary critics for well over a century. It shows the correspondence between Walt Whitman's work and the mystical tradition of East as also interpreted by American Transcendentalists. Enquiry into "self" is the central theme of most of Whitman's work. Two aspects of this enquiry have been investigated in this thesis and compared with the Upanishads: the development of self; and the use of contradictions as a means of conveying meaning. Both aspects support the view that Whitman displays a worldview not in accordance with the popular Western …  Read more

Clinical cancer treatment has focused on the use of cytotoxic agents and/or radiation therapy that target both tumor and normal cells. Consequently, current cancer treatments with chemotherapeutic agents are subject to limitations associated with high toxicity and resistance. The cysteine proteinases cathepsin B and L have been linked to the invasive steps during the metastatic process and could therefore provide new targets for drug development. The present work describes our results with a murine Lewis lung carcinoma model which consists of two cell lines, H-59 and M-27, with different patterns of metastasis in vivo. Using this model, we found that …  Read more

L'électro-déshydratation est une technologie à haut rendement énergétique, dans lequel un champ électrique est appliqué pour augmenter la siccité des déchets de biosolides provenant des traitements secondaires des eaux usées de 15% poids/poids à 30-50% poids/poids. L'électro-déshydratation peut également réduire la teneur en bactéries pathogènes en dessous des limites de détection. Toutefois, dans les deux cas, les mécanismes qui provoquent les effets observés restent à définir ou confirmé. Ainsi, les facteurs qui influent sur les limites de la déshydratation, et le taux et l'efficacité énergétique de l'élimination de l'eau ont été étudiés. Une unité d'électro-déshydratation à l'échelle du laboratoire a …  Read more

Cette thèse traite du développement, de la vérification et de la validation des solveurs à ordre élevé (de précision) pour la simulation de l'écoulement turbulent de fluides. Dans une première phase, une méthodologie pour la vérification des solveurs à ordre élevé est proposée qui examine l'implémentation, dans un système logiciel, des modèles mathématiques qui représentent la dynamique de l' écoulement. La méthode des solutions manufacturées est adoptée, permettant d' évaluer les erreurs de discrétisation et les ordres de précision observées de façon exacte. Ces derniers sont comparés aux ordres de précision théoriques pour une multitude de problèmes avec une complexité …  Read more

By extending the diagrams of materials science, the field is broadened in a natural way. For example, binary phase diagrams are like black boxes, used in the design and simulation of microstructures. They explore a balance of two chemical species, but real alloys have several chemical species, and merit a higher dimensional space. The n-dimensional extension is simplified by dividing the problem into discrete and continuous components. "Discrete" is the identification of behavioural regimes, and their interactions, in a network graph. "Continuous" includes the curvature of boundaries, and the motion through the space. In thermochemical phase spaces, a homogenous alloy …  Read more

Current water-cooling technology used in the metallurgical industry poses a major safety concern. In addition, these systems are expensive to operate and result in significant energy losses. The purpose of the research presented in this thesis was to develop a viable cooling system based on novel heat pipe technology which addresses these problems. This technology employs boiling as the means to store and transfer heat energy. The large heat extraction capacity of the device is owed to two design features: firstly, a separate return line that generates a column of liquid working fluid which drains into the evaporator by gravity, …  Read more

The concept of progressive development--the construction of houses in stages--represents a fundamental principle of the sites and services approach, the most popular policy put forth to deal with the present Third World housing shortage. Through an analysis of the development process occurring in a completed sites and services project in Zihuatanejo, Mexico, this thesis investigates such a concept as a physical phenomenon. The physical evolution of the houses towards consolidation is analyzed with regard to two of the factors that shape the development process: the habitable area, and the construction quality, from which the people's physical priorities for housing are …  Read more

Les podocytes/cellules épithéliales glomérulaires (CEG) sont des cellules terminalement différentiées qui font partie intégrante de la paroi capillaire des glomérules et jouent un rôle clé dans le maintien de la perméabilité sélective glomérulaire. Une des fonctions des podocytes comprend la synthèse de protéines complexes dans le réticulum endoplasmique (RE). Le repliement anormal des protéines dans le RE (stress du RE) conduit à l'activation de la réponse UPR (unfolded protein response). La perturbation de la protéostase, ainsi que l'activation de l'UPR et de l'autophagie sont observées dans plusieurs maladies glomérulaires. Le transducteur de l'UPR inositol-requiring enzyme 1α (IRE1α) est une kinase-ribonucléase …  Read more

Results on the development of Ni-based electrocatalysts for hydrogen evolution in an acidic medium are discussed in the thesis. This topic is of a great importance for the development of a PEM-type hydrogen generator, as a global initiative for the development of clean sustainable energy systems. A number of experimental techniques were used in research: linear dc polarization (Tafel), electrochemical impedance spectroscopy (EIS), potential-decay, inductively coupled plasma (ICP), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The first part of the thesis discusses the results on the influence of alloying nickel by left-hand side transition metals (Fe, Mo, W) on …  Read more

Ce mémoire emploie la méthode Complément Orthogonal Naturel (NOC), la méthode de corps articulé (AB) et la structure du Opérateur spacial algébrique (SOA) développée dans le laboratoire de Jet Propulsion à Caltech, Etats-Unis, pour concevoir des pendules inversés et étudier leur propriétés dynamiques.Une méthode de modélisation simplifiée est aussi présentée en utilisant les équations de Newton-Euler. L’approche de modélisation Lagrangienne n’est pas considérée comme pertinente pour les systèmes de ce niveau de complexité.Les attributs des méthodes de modélisation mentionnés sont analysés du point de vue de leur modularité et la flexibilité nécessaire pour la construction de stratégies de commande hybride …  Read more

Juan Caramuel de Lobkowitz (1606 – 1682) a joué un rôle important dans le milieu intellectuel européen du dix-septième siècle. Par ses œuvres, ce polymathe espagnol a touché à plusieurs disciplines. Caramuel est notamment connu aujourd'hui comme l'une principales des figures de son époque en théologie morale, ainsi qu'en tant qu'auteur de la première encyclopédie mathématique. L'influence religieuse et politique de Caramuel est évidente dans le contexte de l'histoire de l'empire espagnol en Europe centrale durant le début de l'époque moderne. En architecture, la contribution majeure de Caramuel est son approche théorique, sous forme d'un traité sur l'architecture. Des manifestations …  Read more

This thesis examines the model(s) of reading proposed by J. Poulin's novels. On the one hand, a phenomenological analysis enables us to observe textual strategies, such as intertextuality and photographs, which guide the empirical Reader through his readings. On the other hand, the representation of fictional Readers' act of reading, another textual strategy, is also analyzed. As the phenomenological approach to the act of reading has not often been put into practice, our essay allows us to evaluate the reliability of different contemporary theories of the act of reading, particularly that of Iser in his The Act of Reading.  Read more

In plants, retrotransposon copy numbers have been shown to vary from several hundreds to several million. The factors that regulate retrotransposon copy number are poorly known. A model by FLAVELL et al. (1997) proposing different effects of selection in genomes with low numbers of copia-like retrotransposons, against genomes with higher copy numbers of this retroelement, was tested. Non-synonymous to synonymous substitutions ratio (d N/dS), together with the frequency of occurrence of stop codons within the reverse transcriptase sequence of copia -like retrotransposons, were analyzed in relationship to copy number estimates of this retrotransposons. Evidence of purifying selection was detected in …  Read more

Pyrithiamine-induced thiamine deficiency in rats is a well-established animal model of Wernicke's Encephalopathy (WE). This thesis project, submitted as four articles, presents an examination of metabolic events that contribute to the selective neuronal lesions observed in the medial thalamus (MT) of thiamine-deficient (TD) rat. In addition, the phenomenon of glucose-precipitated worsening of neurological status in WE patients (Wallis et al., 1978; Watson et al., 1981) is explored. Lactate accumulation is known to occur selectively in regions of the TD brain, which ultimately express neuronal cell death (McCandless, 1982; Munujos et al., 1996). In Article 1, the metabolic origin and cellular …  Read more

Stephanie de Genlis (1746--1830) is amongst the most productive women authors of her generation. We will base our work upon the research of Catherine Rubinger and Roland Bonnel (in Femmes savantes et femmes d'esprit) in order to describe the society of women authors at the end of the 18th century; we will also look at their literary practices, as well as analyze the environment which contributed to their discourse. We will then study the literary styles favored by de Genlis; Georges May's study on the novel (Le Dilemme du roman) will be used as a first step towards understanding de …  Read more

The sanitary collection, transportation, treatment and disposal of human waste promotes health, improves the quality of the environment and thus, the quality of life in a community. Some poor communities in developing countries, rarely consider inadequate excreta disposal a problem. In absence of sanitation facilities, these communities rely on natural processes to dispose of their waste, wherein the practice of defecating in the open fields or on surface water is prevalent. In communities occupying coastal, waterfront and low-lying areas, human waste is directly disposed of into the surface water such as rivers, canals and sea or in the mudflat to …  Read more

Slider-crank mechanisms are widely used in reciprocating machinery, where transformation from rotational into translational motion (or vice versa) is required. Moreover, the use of these mechanisms is quite common in robotic and mechatronic systems when complex motions are to be produced with rotational actuators. However, the velocity ratio of the slider-crank mechanism is configuration-dependent and thus, elaborate algorithms are required to precisely control its performance. In this thesis, a planar cam mechanism with an oscillating follower is proposed as a device that renders the velocity ratio of the slider-crank mechanism constant, an operation that is termed here velocity-ratio rectification ; …  Read more

The synthesis of substituted non-symmetric tropones has proven to be a considerable synthetic challenge. Particularly, a 3,4,6-tnsubstituted tropone which is required for the total synthesis of CP-225,917 is currently being undertaken by our group. Two approaches towards the synthesis of substituted tropones are presented. Both utilize linear diene precursors which are closed to 7-membered cycloheptene rings via ring closing metathesis. In the first method, linear precursors are synthesized by addition of nucleophilic substituents to carbonyl groups to form alcohol groups. After forming the cycloheptene ring, the alcohol groups are eliminated to form the tropone. The second method uses an oxidation …  Read more

This thesis is dedicated to the study of load models and control of residential appliances. A load model base on computing an average dwelling augmented by a diversification process is introduced. This model is well-suited for studying the load group's natural and controlled dynamics. To validate this model, extensive simulations are employed. Two different strategies are proposed for the control of residential appliances: (1) aperiodic ON/OFF switching of the appliances; (2) continuous control of the thermostat temperature settings. A mathematical framework based on Pulse Width Modulation theory is developed for the remote ON/OFF switching of residential appliances. Load Management System …  Read more

Cell cycle quiescence, a state of reversible arrest, is vital for the coordinated development of an organism and is a feature shared by many cell types, including stem cells. Suggested to play a role in protecting stem cells, it may also be adopted by cancer stem cells to their advantage. To enhance our knowledge on the regulation of cell cycle quiescence, we used the G2/M arrested germline of dauer Caenorhabditis elegans larvae as a model. AMP-activated kinase (AMPK) regulates the arrest of these germ cells, where compromised AMPK function leads to cell cycle progression. Using sensitized C. elegans dauer larvae, …  Read more

This thesis describes an investigation of the viscosity of dilute emulsions and suspensions of rigid and flexible thread-like particles. The method of presentation needs some explanation. It has been written to achieve brevity, without loss of clarity, and at the same time to make it possible for its different parts to be published in the scientific literature with little or no modification. For the benefit of the reader, each part has been made complete in itself with separate introduction and bibliography.  Read more

The vasopressin level was measured by the antidiuretic assay after an extraction procedure based on adsorption of the hormone on an ion exchange resin. Modifications and problems related to these procedures have been discussed. The method was applied for: (a) Measurement of plasma ADH in dogs with surgically induced congestive heart failure and in patients with congestive heart failure. There was no definite correlation between the level of plasma vasopressin and the occurrence of cardiac edema. (b) Studying the effect of chlorpropamide administration on the level of urinary ADH in a patient with diabetes insipidus in order to have some …  Read more

Najafabadi, Hamed Shateri (Supervisor2)  Read more

Dans la nature, ainsi que dans le contexte des applications médicales, les bactéries vivent souvent dans des environnements très complexes tels que le sol, les déchets, les tissus végétaux et animaux. Par conséquent, les bactéries ont développé de nombreux modèles de mouvement pour leur croissance et leur survie dans un large éventail d'habitats. La compréhension des mouvements bactériens à travers des micro-confinements créés par l'homme peut être importante pour les applications médicales et industrielles, pour le biocalcul basé sur les bactéries, ainsi que pour les biocapteurs et les contrôles industriels de la fermentation. La majorité des études se sont concentrées …  Read more

The word "Pituitary" is derived from the Greek - pituita, meaning mucus or phlegm (1). In Galenic times (131 - 200 A.D.), it was thought that a by-product of animal spirits passed through this small body and filtered down through cribriform plate into the nose. [...]  Read more

L'objectif de cette étude est d'examiner le changement des habitudes alimentaires des enfants âgés de 8 à 10 ans et de 15 à 17 ans en décrivant les déterminants potentiels des changements alimentaires lorsque les enfants grandissent, parmi lesquels figurent l’indice de masse corporelle (IMC) initiale, le sexe de l’individu, l’obésité maternelle, l'obésité paternelle et le fait de souper en famille. Cette étude a exploité un ensemble de données secondaires qui ont été recueillies à l'aide d'une conception de cohorte longitudinale - la cohorte de l’Enquête sur le l’adiposité et le mode de vie chez les jeunes du Québec (QUALITY). …  Read more

Optical coherence is a fundamental property of broadband light sources and plays a central role in applications such as optical coherence tomography (OCT), biomedical imaging, precision metrology, and ultrafast spectroscopy. The primary motivation of this thesis is to investigate and characterize the coherence properties of pulsed fiber laser and supercontinuum (SC) sources, and to understand how coherence evolves under nonlinear spectral broadening and noise processes. A numerical framework is developed to model a Gaussian pulsed source and supercontinuum generation in a hybrid nonlinear fiber using the generalized nonlinear Schrödinger equation (GNLSE). Coherence degradation of a pulsed laser source due to …  Read more

This study traces the complex development of a relatively "minor" pan-Indian deity---Hayagriva---who, by the 14th century C.E., is revered as a full form of the Supreme Lord Viṣṇu in the Sri Vaiṣṇava tradition of South India. From the perspectives of mythology, iconography, and ritual, the analysis examines both the diachronic and synchronic dimensions of the images of the deity corresponding to the three-fold division of Hindu texts: (1) pan-Indian "mainstream" (Vedas, Epics, Puraṇas), (2) pan-Indian sectarian (Agamas), and (3) regional sectarian (hymns of the Al̲vars and Sri Vaiṣṇava Acaryas). Firstly, the study questions the structural interpretation of Hindu mythology by …  Read more