McGill University Thèses et mémoires par auteur commençant par S

Autrefois considérée comme limitée à l’enfance, la plasticité corticale à l'âge adulte introduit une intéressante opportunité d’étudier comment le cerveau conserve sa capacité permanente à changer et à s’adapter en réponse à un environnement complexe et dynamique. Des travaux récents ont démontré que la plasticité constitue un principe fondamental dans l’organisation neuronale de la vision binoculaire. L’architecture neuronale du système visuel des primates fournit un terreau fertile pour étudier la plasticité corticale en raison à la fois de son étude extensive et de la possibilité d’évaluer les changements dans les fonctions cérébrales par la mesure des changements de la perception …  Lire la suite

This study presents a novel methodology to characterize material plastic behavior within a practical range of stresses, strains, strain rates, and temperatures encountered in the metal cutting process. The methodology is based on integrating a newly developed analytical model with quasi-static tests and orthogonal cutting experiments that incorporate a laser heating system. Friction and heat transfer models are developed to describe the tribological and thermal interactions at the tool-chip interface. These models are implemented in a FEM package in order to improve the accuracy of the simulation of the machining process. The new analytical model, which is developed to predict …  Lire la suite

Fish viscera are produced in large quantities in the fishing industry and represent a waste disposal and environmental pollution problem. However, this material is a rich source of trypsins that may have some unique properties, such as high molecular activity at low processing temperature, low thermostability, and high pH optimum/pH stability, for both basic research and industrial applications. The main objectives of this project were to extract, purify and characterize trypsin from the pyloric ceca of hoki (Macruronus novaezealandiae ), which is by far the most important commercial fish in New Zealand. Trypsin was purified from the pyloric ceca of …  Lire la suite

Le récepteur d'aryl hydrocarbone (AhR) est un facteur de transcription activé par un ligand qui est fortement exprimé dans les poumons. Bien que le rôle de l’AhR dans la médiation des réponses toxiques de la dioxine a été largement étudié au cours des dernières décennies, son importance dans la régulation de la physiologie cellulaire normale n'a été appréciée que récemment. Des études ont montré que l’AhR favorisait la progression du cycle cellulaire et supprimait l'apoptose en régulant à la hausse les voies de survie essentielles dans les cellules tumorales. Dans cette étude, nous avons émis l'hypothèse que l’AhR améliore l'activation …  Lire la suite

Après une lésion médullaire (LM), une personne va devoir modifier son approche à certaines activités quotidiennes (Alizadeh et coll., 2019). Pour aider les personnes ayant une LM à s’adapter et prospérer, des programmes de mentorat par les pairs ont été mis en œuvre dans les milieux communautaires et en réadaptation, afin d'établir une relation ciblée et unidirectionnelle entre un mentor et un mentoré (Shaw et coll., 2019). Ces programmes peuvent être bénéfiques pour les personnes ayant une LM sous nombreux aspects, incluant le plan d’adaptation, la connexion, le développement personnel, l'indépendance, les connaissances, et la participation (Rocchi et coll., 2022). …  Lire la suite

Interactions among zinc deficiency, energy restriction, immunity and Heligmosomoides polygyrus (Nematoda) infection in mice were investigated. Mice were fed zinc-sufficient (Zn+: 60mg zinc/kg diet), zinc-deficient (Zn$-$: 0.75 mg/kg) or pair-fed (PF) diets. Liver and serum zinc concentrations were reduced in Zn$-$ mice, but zinc content of worms was unaffected by host diet. Both zinc deficiency and energy restriction accelerated worm maturation during a primary infection, but zinc deficiency caused stunting of female worms. Energy restriction led to a anteriorad distribution of worms along the intestine whereas zinc deficiency led to a posteriorad distribution. Enhanced parasite survival in Zn$-$ and PF …  Lire la suite

Les matériaux ont façonné les civilisations humaines de l'âge de pierre à nos jours. Outre la modification des constituants chimiques, les matériaux cellulaires ont fourni une méthode de conception de matériaux prometteuse pour obtenir des matériaux avancés légers et performants. En adaptant leurs microarchitectures typiquement périodiques, les métamatériaux offrent de nombreuses propriétés exotiques au-delà de celles trouvées dans les matériaux naturels. Dans la présente étude, nous présentons une stratégie rationnelle pour concevoir des métamatériaux ferroélectriques intelligents et explorer l'influence de la densité relative et de la topologie cellulaire sur les propriétés multiphysiques efficaces. En particulier, des topologies cellulaires alternatives sont …  Lire la suite

Antibiotic resistance is widely recognized as a risk to global public health. The misuse and overuse of antibiotics has promoted the emergence of multi-drug resistant bacterial strains that threaten to compromise the current repertoire of antibiotics. Among the most severely affected classes of antibiotics are the aminoglycosides. The most widely observed mechanism of resistance against aminoglycosides is inactivation through a series of detoxifying enzymes. Aminoglycoside phosphotransferases (APHs), also known as aminoglycoside kinases, are of special clinical concern due to their prevalence and broad substrate spectra. The APHs are a large family of structurally related enzymes, all sharing a fold similar …  Lire la suite

RésuméLes protéines de liaison du GTP de la famille Rab sont bien connues pour le rôlequ'elles jouent dans la régulation du transport vésiculaire intracellulaire requis lors de latransduction de signaux, ainsi que la croissance, la différentiation et le développementcellulaire. Les protéines d'hydrolyse du GTP (les GAPs) agissent comme régulateursnégatifs pour contrôler la durée de vie des Rabs à l'état actif. RN-Tre est un GAP Rabconservé évolutivement et il a été démontré que cette protéine était GAP-active sur Rab5in vitro. Cependant, des cultures cellulaires précédentes sur le RN-Tre mammifère ontmontré des résultats controversés par rapport au rôle du RN-Tre dans la …  Lire la suite

The mechanical behaviour of a rubber-like elastic material is characterized by its strain energy function, which depends on the type of rubber, including its molecular structure and cross-linking. This thesis presents the results of a series of uniaxial tests that were conducted on natural rubber samples, for the purpose of determining the form of its strain energy function. The simplest model that provides a good match with the stress-strain data is chosen to identify the strain energy function. The validation of the model chosen is performed through an experiment involving fluid loading of a natural rubber membrane that is fixed …  Lire la suite

Au cours des cinq dernières décennies, la taille des dispositifs électroniques dans une puce a diminué de manière exponentielle conformément à la loi de Moore. Alors que les appareils électroniques deviennent de plus en plus petits, la réduction progressive de la technologie est de plus en plus mise à mal par de nombreux problèmes émergents. L’un des problèmes les plus importants est la variation d’un dispositif à l’autre provoquée par des dopants discrets aléatoires (RDD) (également appelés impuretés aléatoires). L’effet RDD peut entraîner diverses variations des propriétés du dispositif, telles que les structures de bandes électroniques matérielles et le transport. …  Lire la suite

Dans ce mémoire, nous présentons des simulations à partir des premiers principes pour l'étude des variations dispositif-à-dispositif induites par dopant ponctuel aléatoire (RDD) dans des canaux nanoFET en Si. Nos simulations sont à partir des premiers principes atomiques et libres de paramètre, en combinant les fonctions de Green hors équilibre (NEFG) avec la théorie de la fonctionnelle de densité (DFT). Afin d'adresser le problème de la dispersion dûe au désordre et aux moyennes de configuration, l'approximation du potentiel cohérent (CPA) et la correction vertex hors équilibre (NVC) sont employées. Afin de calculer la variance de la conductance dûe au RDD, …  Lire la suite

Learning deficit has been one of the most difficult disease presentations to understand in neurodevelopmental/neurodegenerative disorders. However, monogenetic disorders permit a better understanding of how loss-of-function (LOF) mutations generate specific learning dysfunctions. One such example of a devastating monogenic X-linked neurodevelopmental/neurodegenerative autism-related disorder is Christianson Syndrome (CS), resulting from SLC9A6 gene mutations. CS patients suffer from epilepsy, ataxia, and learning difficulties; many of them die at a young age. However, treatment options are limited due to our poor understanding of the underlying etiology. It has been described that the SLC9A6 gene encodes (Na+, K+)/H+ exchanger 6 (NHE6), a regulator of …  Lire la suite

This thesis presents a Battery Energy Storage Systems simulation and study platform. Its purpose is specifically to perform energy storage system asset sizing with the objective of rate of return maximization. The simulation platform contains the models for the main components, the controller of the Battery Energy Storage Systems as well as a Return on Investment calculation model.Based on the simulation platform, methodologies for finding the optimal asset sizes are proposed to provide peak shaving service for both front-of-meter and behind-the-meter Battery Energy Storage Systems installations. In the front-of-meter case, the Hydro-Quebec Hemmingford substation peak shaving project is studied by …  Lire la suite

Multiple sclerosis (MS) is a chronic, neuroinflammatory, and demyelinating neurodegenerative disorder that affects central nervous system (CNS) neurons. Neurodegeneration leads to axonal damage and neuronal death, which contribute to neurological symptoms and irreversible disease progression in MS. The pathophysiology and mechanism of neuroinflammatory and neurotoxic insults in MS are complex and poorly understood. 14 neuronal microRNAs (miRNAs) have been reported to be commonly dysregulated in EAE-affected CNS neurons. These miRNAs were predicted to regulate mRNAs implicated in SG assembly by gene ontology analysis. In this thesis, 7 upregulated miRNAs were identified to promote neuroprotection in neurons exposed to multiple MS-relevant …  Lire la suite

The circular economic (CE) model of production and consumption serves as a sustainable alternative to the prevailing linear “take-make-waste” model by significantly reducing the environmental impacts of economic growth. For the CE to be effective, consumer participation is essential. This thesis investigates consumer participation in the CE through four essays, focusing on product purchase and use behaviors that extend product lifespans (PLE), which is vital for the successful implementation of the CE. The first essay examines PLE-oriented product use behaviors, such as product care and upcycling. Based on a systematic literature review, this essay develops a conceptual framework that summarizes …  Lire la suite

Lijun Sun (Supervisor1)  Lire la suite

Chronic ligation of one pulmonary artery results in pulmonary vascular remodelling and bronchial angiogenesis, known as postobstructive pulmonary vasculopathy (POPV). In previous studies of POPV, we found that responses of pulmonary arteries to 5-HT and of veins to histamine were markedly increased, but the role of putative factors, such as structure, endothelial modulation and alterations in receptors remains unknown. First, we examined the role of these mechanisms in the differential responses of pulmonary arteries and veins of normal guinea pigs to histamine and 5-HT, using a novel lung explant technique. We found that veins contracted more to both agonists than …  Lire la suite

Soy proteins have been utilized in many applications such as food ingredient, bio-based films and composites. The advantages of utilizing plant proteins as feedstocks for bio-based polymers are their biodegradability, biocompatibility and low toxicity. Because soy proteins are used in the food industry, and given that it their utilization is becoming controversial due to the bio-based material versus food debate, other protein sources should be investigated as replacement. Therefore, a thorough review of the literature about proteins source which are not commonly used for bio-based polymer applications was performed. Through this review, it was found that canola proteins have an …  Lire la suite

Guthrie, R. I. L. (Advisor)  Lire la suite

La cicadelle de la pomme de terre [CPT, Empoasca fabae (Harris)], qui affecte plusieurs cultures dont la luzerne (Medicago sativa L.), constitue un problème récurrent dans plusieurs régions du Québec. L'objectif du présent projet était d'évaluer différents outils de gestion afin de réduire les effets négatifs causés localement par ce ravageur dans les champs de luzerne. Deux expériences ont été menées à deux sites au Québec pendant trois saisons pour évaluer les effets d’applications d'insecticides, de l'utilisation de cultivars tolérants à la CPT et de mélanges avec des graminées sur les populations de CPT, le rendement fourrager et la valeur …  Lire la suite

Guo, Jin (Supervisor2)  Lire la suite

Actuellement, l'expérience utilisateur des réseaux sociaux en ligne (Online Social Networks) est difficile lorsqu'un utilisateur a à valider des identités d'autres pour se connecter. Compte tenu des attaques rampantes de vol d'identité sur OSN, il est parfois difficile de distinguer si la personne à connecter sur OSN est celle qui l'utilisateur connaît-il dans la vie réelle. Pour cette raison, la construction d'un système de validation d'identité est nécessaire pour protéger l'intérêt des utilisateurs ainsi que pour améliorer de l'expérience utilisateur.Dans cette thèse, nous présentons un système de validation d'identité - CredFinder pour OSN développé en plate-forme des dispositifs mobiles. Trois …  Lire la suite

Silva, Andrey Da (Supervisor2)  Lire la suite

Muis, Krista (Internal/Cosupervisor2)  Lire la suite

Poschke, Markus (Supervisor1)  Lire la suite

Dans le domaine de la dynamique des structures, les systèmes conservatifs autonomes sont caractérisés par la présence de familles continues d'orbites périodiques dans l'espace des phases, communément appelées \emph{modes de vibration}. L'ambition principale de l'analyse modale est le calcul précis des fréquences naturelles et de la forme des modes de vibration correspondants de systèmes mécaniques. En effet, dans le cadre linéaire, ces deux quantités permettent de correctement prédire les conditions selon lesquelles les systèmes forcés associés vont entrer en résonance vibratoire. Caractériser les modes de vibration de systèmes mécaniques non-linéaires mais réguliers (systèmes gouvernés par des équations différentielles ordinaires qui …  Lire la suite

This thesis presents the techniques and results of our x-ray structural studies of strained Ga$ sb{1-x}$In$ sb{x}$As epilayers grown on GaAs (001) by metallorganic chemical vapor deposition. By combining conventional x-ray techniques with newly developed glancing incidence and reflectivity measurements, we study both the out-of-plane and the in-plane structure. We also obtain direct information on the mechanisms of the structural relaxation which occurs in these systems. The techniques we have used are based on using a conventional x-ray source and could be widely used to characterize and study growth processes and sample quality. Using the conventional characterization of the positions, …  Lire la suite

IntroductionPlusieurs études ont démontré que le modèle de soutien à l'emploi « Individual Placement and Support » (IPS - Placement et soutien individuels) constitue une méthode efficace pour aider un grand nombre de personnes qui ont des troubles graves de santé mentale à obtenir et conserver un emploi régulier. Ces études incluent une étude expérimentale menée à Montréal, Canada. Très peu d'études, toutefois, ont évalué la coût-efficacité de IPS en comparaison avec des services traditionnels. Objectif Évaluer la coût-efficacité du modèle IPS en comparaison avec des services d'insertion socio-professionnelle habituels, en utilisant des données de l'étude montréalaise. Méthodes Au total, …  Lire la suite

Vertical Bell Lab Layered Space-Time (VBLAST) is an emerging spatial modulation technique, that provides high spectral efficiency due to its use of multiple transmit and receiver antennas. We present novel schemes; consisting of combinations of Transmit Antenna Selection (TAS) with Power Allocation (PA), to improve the error rate performance of VBLAST systems. Our schemes provide significant performance gain over VLAST because of enhanced transmit diversity introduced by transmit antenna selection. Our scheme may be used for uplink wireless system, where the total power is limited by the mobile terminal battery. The effect of limited rate feedback link is investigated by …  Lire la suite

The major part of this thesis is to obtain basic information in regard to changes of amino acids and middle molecular substances in fulminant hepatic failure (FHF) using a galactosamine induced rat model. The changes of these substances after hemoperfusion were also studied. A generalized elevation of amino acid concentrations is demonstrated in the systemic blood plasma, portal plasma, CSF, cerebrum, liver, kidney and skeletal muscle tissues in GalN-FHF. The skeletal muscle is found to constitute the greatest source of accumulated amino acids in FHF. The other tissues also contribute to the increased amino acids in the body as a …  Lire la suite

Background: Although there is empirical support for peer support programs for individuals with spinal cord injury (SCI), they have not been embedded within most Chinese rehabilitation hospitals. This study is to explore how Chinese adults with SCI needed and viewed hospital-based peer support programs. Methodology: Six inpatients with SCI from Tianjin, China were interviewed twice. The first interview explored participants' background (e.g., family) and life experiences pre- and post-injury. The second interview focused on their perspectives on peer support and their vision of delivering peer support programs. Thematic analysis was conducted. Results: Participants have varied life experiences pre- and post-SCI. …  Lire la suite

Hydrogen is considered to be the fuel of the future as it is clean and abundant. Together with the rapidly developing fuel cell technology, it can sustain an environmentally sound and efficient energy supply system. Developing the technologies of palladium-based membrane for hydrogen separation and palladium nanostructured materials for hydrogen sensing and hydrogenation catalysts makes the "hydrogen economy" possible. This is because these technologies will allow for commercially viable production of comparatively cheap and high-quality hydrogen, and safety of its application. Based on the market requirements and interest in the development of a hydrogen economy, the purposes of this thesis …  Lire la suite

Stephens, David (Supervisor2)  Lire la suite

A full-space optimization framework is developed for aerodynamic shape optimization. Additionally, a convergence of the optimization problem independent of problem size is attained through the use of second-order information, while maintaining a tractable computational and implementation cost by employing automatic differentiation. Furthermore, a novel preconditioner based on the reduced-space is extended to accommodate additional aerodynamic and geometric constraints to avoid ill-conditioning of the resulting enormous full-space system. All the necessary ingredients to perform scalable aerodynamic shape optimization are established, which include a high-order flow solver, geometry and mesh parameterizations, adjoint-based sensitivities, and an optimizer. A primal-dual active-set method is then …  Lire la suite

An approximation of the Hessian matrix is developed and used to accelerate the convergence of an adjoint-based aerodynamic shape optimization framework. Exact analytical formulations of the direct-direct, adjoint-direct, adjoint-adjoint, and direct-adjoint Hessian approaches are presented and the equivalence between the adjoint-adjoint and direct-adjoint formulations is demonstrated. An approximation of the Hessian is obtained from the analytical formulation by partially solving first-order sensitivities to reduce computational time, while neglecting second-order sensitivities to ease implementation. Error bounds on the resulting approximation are presented for the first-order sensitivities through perturbation analysis and eigenvalue analysis. The proposed method is first assessed using an inverse …  Lire la suite

An understanding of the total blood supply of malignant tumours is of fundamental importance not only to the surgeon interested in chemotherapy, but also to the radiotherapist and the medical oncologist. This is because the effect of cancericidal agents depends to a great extent upon the amount of agent delivered directly to the tumour cells within the tumour. [...]  Lire la suite

Before the Second World War, from 1934 to the outbreak of the War, trade between Japan and Canada consisted almost entirely of Canadian experts. Japan imported 4.7 times as much from Canada as she exported to that country. The average value of Canadian imports from Japan in the 1935 to 1939 period was $4,649,000 (Canadian dollars) annually, which accounted for only 0.67 per cent of the average annual value of Canadian imports from the world at this period, (see Table 1.1). After the War, formal Japanese-Canadian trade relations were resumed and by 1951 Japan had a substantial trade deficit with …  Lire la suite

Guillaume Bourque (Supervisor1)  Lire la suite

This thesis examines Pakistani female migrant domestic workers and prostitutes in the United Arab Emirates. Pakistani women are not legally allowed to work as domestic workers in the UAE. This pushes their work into the invisible economy and subjects them to the same vulnerabilities as prostitutes. An exploration of the wider context and the relationship between Pakistan and the UAE helps to understand why and how abuse occurs. Because the UAE is developing at such a rapid pace, it is useful to interpret it as a "heterotopia," or a site where order is subverted. This interpretation helps explain why Pakistanis …  Lire la suite

Cette thèse se propose de décrire l'évolution de l'Islam indonésien et le rôle complexe qu'ont joué les 'ulamà' dans l'histoire moderne de l'Indonésie, et plus particuliérement pendant la période de l'occupation japonaise. Par opposition à la politique hollandaise, les japonais , quant à eux, choisirent les 'ulama' afin que ces derniers participent à leur administration gouvernementale. Les 'ulama' saisirent cette occasion imprèvue pour préparer les indonésiens à obtenir leur indépendance. D'autre part, les japonais essayérent de "nipponiser" l'Islam indonésien mais cet éffort echoua car les 'ulama' les resistérent.  Lire la suite

Cette thèse se propose de décrire l'évolution de l'Islam indonésien et le rôle complexe qu'ont joue les ulama dans l'histoire moderne de l'Indonésie, et plus particulierement pendant la période de l'occupation japonaise.  Lire la suite

Moulds belonging to the Fusarium genus were isolated that are able to utilize coumarin as the sole carbon source in a medium containing inorganic nitrogen and various salts. Factors affecting the growth of the cultures and the rate of coumarin degradation were studied. [...]  Lire la suite

The organic forms of nitrogen in the soil are derived largely from plant residues, such as stubble, weeds, leaves, and pine needles etc. The amount of protein in these organic materials is often very large. For example, the protein content of cereal straw and wood shaving may be as much as 2 or even 15 per cent, and the protein content of certain defatted meals, may be 40 or even 60 per cent. The phenomenon of growth and death of bacteria in ordinary culture media has been studied in considerable detail.  Lire la suite

This monograph documents my effort as well as examines the process of developing sustainable support in the use of instructional technology in a consulting project over a ten month period. It is written in a narrative recording the occurrences and my interventions during this ten-month period, along wdth my reflections in italics in light of the review of the literature and the analysis of the narrative. This results in a deeper understanding and insights in the field of instructional technology, and leads to the elaboration of a mission statement, which represents my present thinking about instructional design and consultation.  Lire la suite

Les infections parasitaires à nématodes représentent une charge de morbidité grand pour le bétail et les populations humaines dans les pays en développement. L'ivermectine est l'un des médicaments antiparasitaires nématocides les plus efficaces, mais son succès est menacé par le développement d'une résistance aux médicaments chez les parasites. Ce projet étudie un marqueur génétique de résistance affectant la morphologie des neurones chimiosensoriels, appelés gènes remplissage-de-teinture dysfonctionnels (dyf). En utilisant le nématode modèle Caenorhabditis elegans, j'ai examiné deux hypothèses expliquant pourquoi les mutations Dyf confèrent une résistance aux médicaments. Premièrement, pour tester si la résistance à l'ivermectine médiée par les gènes …  Lire la suite

This study critically analyzes Critical Buddhism (hihan bukkyo ; hereafter: CB) as a philosophical and a religious movement; it investigates the specific basis of CB, particularly the philosophical categories of critica and topica, vis-a-vis contemporary theories of knowledge and ethics, in order to re-situate CB within modern Japanese and Buddhist thought as well as in relation to current trends in contemporary Western thought. This study is made up of seven chapters, including the introduction and the conclusion. The introduction provides the religious and philosophical context as well as the motivations and intentions of the study. Chapter 2 with the title …  Lire la suite