McGill University Thèses et mémoires par auteur commençant par A

Dans les jeux vidéo, le comportement des personnages non jouables (PNJ) a de profondes implications en tant qu'aspect fondamental de la création d'environnements virtuels immersifs et captivants : les interactions avec les PNJ jouent un rôle essentiel dans l’expérience globale du joueur, qu’il s’agisse de s’aventurer dans des quêtes, d’échanger des ressources ou de participer à des combats. Dans le domaine des jeux d'infiltration, les PNJ jouent généralement le rôle de gardes surveillant une zone, et leur comportement constitue un facteur déterminant qui peut soit entraver, soit faciliter les efforts de dissimulation du joueur. Pour ce faire, les PNJ doivent …  Read more

Septic shock is a leading cause of death in intensive care units. As part of the septic process, the endothelium becomes activated and propagates the septic condition. It has become evident that reactive oxygen species (ROS) are involved in the signaling of mediators of sepsis, such as tumor necrosis factor-alpha (TNF-alpha) and the lipopolysaccharide coating of gram-negative bacteria (LPS). An important source of these ROS is NADPH oxidase, which is a ubiquitously expressed enzyme complex that also exists in endothelial cells (EC). We showed that O2- from NADPH oxidase was important for LPS, as well as TNF-alpha, induction of two …  Read more

Le cancer de l'ovaire (OvCa) demeure le cancer gynécologique le plus mortel avec un taux de survie de 27%, ce taux n'ayant pas changé depuis les 30 dernières années. Durant la progression du cancer épithélial de l'ovaire (EOC), le plus commun des OvCa, les cellules se dispersent dans la cavité péritonéale et peuvent par la suite causer des métastases à d'autres organes. Les vaisseaux sanguins tumoraux désordonnés occasionnent souvent une fuite du liquide lymphatique dans l'abdomen provoquant une accumulation d'ascites favorisant la croissance de cellules tumorales disséminées (DTCs). Les DTCs se retrouvent fréquemment sous forme de sphéroïdes multicellulaires présentant une …  Read more

Marino, Faleh Tamimi (Supervisor1)  Read more

Asthma is a heterogeneous disease which affects 300 million people worldwide. Characterized by airway hyperresponsivness and inflammation, no curative therapy exists to date. Immune cell infiltration into the airways is a major characteristic of the disease. More specifically, T helper (Th) cells with a type 2 profile have been found in asthmatic airways. Moreover, the airway smooth muscle (ASM) cells have been widely studied in the past. These structural cells secrete a multitude of factors that are involved in the pathogenesis of the disease. An increase in the number and the size of ASM cells is also a major feature …  Read more

BACKGROUND: Liver transplant (LT) recipients, patients with type 2 diabetes (T2D), and people with HIV represent at-risk populations for nonalcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC). These populations require monitoring to prevent hepatic failure. We aimed to: 1) provide a review on non-invasive tools (NITs) for NAFLD and liver fibrosis in patients with T2D; 2) determine incidences and predictors of NAFLD and NASH in LT recipients using NITs, namely Fibroscan with controlled attenuation parameter (CAP) and cytokeratin 18 (CK-18), and evaluate the diagnostic performance of NITs compared to liver histology; and 3) determine the rate of surveillance of …  Read more

Cette thèse propose un cadre de système de contrôle de microréseaux distribués (DCS) pour contrôler les atouts de microréseaux, y compris les ressources énergétiques distribuées, les charges et le point d'interconnexion. La conception utilise un système multi-agents, dans lequel chaque atout est affecté à un agent. Les agents utilisent des communications de voisin à voisin pour se coordonner. L'objectif des travaux est de démontrer la capacité du DCS à répondre aux exigences de répartition et de transition des microréseaux. Dans le cadre de la conception de l'agent, l'optimisation distribuée pour chaque fonction de micro-réseau est réalisée par l'algorithme de consensus. …  Read more

This thesis shows that series capacitive compensation of transmission lines by a combination of Static Synchronous Series Compensator (SSSC) and dielectric capacitors lowers the cost of series compensation. The SSSC has two functions: (1) to provide some series capacitive reactance compensation; (2) to damp out incipient unstable Subsynchronous Resonance (SSR) modes. Digital simulation using HYPERSIM shows that for an overall capacitive depth of compensation of 0.7 pu, the SSSC component is only about 1/3 of the capacitive Mvar. Based on the transient stability limit, the transmissibility of the line is increased by a factor of 2.23 for a depth of …  Read more

We examined the hypothesis that maturation ameloblasts degrade enamel matrix in a manner analogous to bone matrix degradation mediated by osteoclasts. Thus, we assessed the distribution of the cation-independent mannose 6-phosphate receptor (MRP) and lysosomal enzymes in the enamel organ and in the alveolar bone surrounding the rat incisor. The MPR was observed on the ruffled border of the ruffle-ended ameloblast (RA) but not on the distal call membrane of the smooth-ended ameloblast (SA), although both cells demonstrated strong immunoreactivity in the Golgi region. Immunogold localization of cathepsin B showed more labelling on the distal end of RA than SA, …  Read more

Les écouteurs personnalisés sont une classe émergente de technologie portable composée d'une résine prépolymère malléable. Les écouteurs sont moulés pendant un processus de durcissement de 60 secondes pour obtenir la forme exacte de l'oreille. La résine est composée d'un mélange de méthacrylates, durcis dans un thermodurcissable photo polymérisable. Les écouteurs sont munis de DEL bleues (λ=470 nm) qui initialisent le durcissement. Cependant, la photopolymérisation est exothermique, ce qui rend le procédé peu sécuritaire pour les utilisateurs. La résine durcie présente également un rétrécissement volumétrique, ce qui entraîne une mauvaise adhésion de la résine à la gaine. Cette étude vise à …  Read more

Meyers, Christine M (Internal/Cosupervisor2)  Read more

Haggard, Daryl (Supervisor2)  Read more

Cellular Cardiomyoplasty (cell therapy for myocardial regeneration) targets the basic pathophysiology of heart failure and represents a novel technique for augmenting the function of the failing heart. Previous studies have demonstrated massive mechanical losses in the first few minutes. Thus, efforts to reduce mechanical losses may prove more beneficial than those directed against biological losses alone. We believe that "Wash-out" into the disrupted blood vessels is responsible for these early losses. In the first part of this study we hypothesized that by increasing the size of the injectate, the amount of immediate losses can be reduced achieving better retention. Using …  Read more

Purpose: The aim of this study is to construct a new drug delivery system for milrinone (Mil) using microparticles. This novel technology enhances drug bioavailability, decreases cytotoxicity and dosage frequency with future implication in the treatment of patients with end-stage heart failure. Methods: Polylactic-co-glycolic acid microparticles (PLGA-MPs) loaded with Mil were prepared by double emulsion-solvent evaporation technique. In-vitro release kinetics was estimated at T: 37C° and PH: 7.4. Twenty-four female Lewis rats were randomized into one of the three groups (n=8 per group), one week after left anterior descending artery ligation: Group I received intravenous (IV) injection of PLGA-MPs (250 …  Read more

As is the case for high-energy photon beam therapy (> 10 MV), secondary neutrons are produced during electron and proton therapy. These neutrons, which extend in energy up to the maximum energy of the primary beam, result in a whole-body radiation dose to the patient that presents a risk for a second, radiation-induced, cancer. To account for the second-cancer risk, it is necessary to understand the spectra of the neutrons involved.In this research project, the spectra of secondary neutrons arising from clinical electron and proton beams were measured. The neutron spectra around electron beams were measured for a Varian linear …  Read more

Meshless Methods such as the Element-Free Galerkin (EFG) method have been proposed as an improvement over Finite-Element Methods because they do not require a mesh. In electromagnetics, they have largely been applied to scalar, quasi-static, deterministic problems. This thesis considers an EFG method for a vector, wave, eigenvalue problem: finding the TM modes of a waveguide using the transverse magnetic field as the unknown. Two approaches are described to represent a vector field using EFG: one approach separates the field into its Cartesian components as in finite elements, and the other separates the field into a rotational and an irrotational …  Read more

Genetic characterization of the mdh-sucCDAB operon, encoding enzymes of the TCA cycle, was performed. Isolation of a sucA knock-out mutant was attempted through homologous recombination with plasmids carrying a mutated fragment of the sucA gene. Several strains were screened for the expected phenotype of a 2-OGD mutant. Carbon-source utilization phenotype of the tested strains did not reveal highly dissimilar growth patterns in comparison to wild-type levels. PCR amplification of these strains did not yield the expected band size of a mutant copy of the gene. Furthermore, Southern blot analysis of the putative mutants was inconclusive in confirming their identity. Therefore, …  Read more

Model Driven Engineering (MDE) research has achieved major progress in the past fewyears. Though MDE research and adoption are moving forward at an increasing pace,there are still few major challenges left to be addressed. Model Transformations (MT)represent an essential part of MDE that is gradually reaching maturity level. Testing MThas been shown to be a challenging task due to a new set of problems. In this thesis weattempt to complement the work done so far by the research community to address MTtesting challenges.We use findings from the research in classical testing to create a prospective view on MTtesting challenges and …  Read more

All-fiber supercontinuum sources have attracted significant interest in numerous applications due to their robustness, compactness, lightweight nature, and easy integration process. Chalcogenide glasses are excellent choices for developing all-fiber supercontinuum sources because of their high nonlinearity and wide transmission windows in the mid-infrared region. However, the majority of the chalcogenide glasses contain toxic elements such as arsenic (As) and antimony (Sb), which limit their applications in healthcare systems, biosensor fabrication, pharmaceutical industry, etc. On the contrary, the chalcogenide glass Ge20Se60Te20, also referred to as GST, is free of these toxic elements, making it suitable for these particular applications. To our …  Read more

La théorie de la dualité est un sujet important dans la théorie des automates qui mène à une étroite relation entre les automates et les logiques modales. Ces dualités sont tout à fait dans l'esprit des dualités classiques de type Stone. Dans un document récent de Hundt et al. cela a été étudié dans le cadre des automates probabilistes équipés d'une notion d'observation. Leur motivation a été de comprendre comment raisonner sur les systèmes avec des états cachés. Il s'est avéré difficile de formaliser cela correctement en utilisant la théorie des catégories, et la notion intuitive de la dualité qui …  Read more

Kahn, Sarilee (Supervisor2)  Read more

Tchervenkov, Christo I (Supervisor1)  Read more

Abdulkarim, Bassam (Supervisor1)  Read more

Rho GTPases are a subfamily of the Ras superfamily of proteins, that are responsible for cell growth and cytoskeletal dynamics. Rho GTPases are positively regulated by guanine nucleotide exchange factors (GEFs), and negatively regulated by GTPase-activating proteins (GAPs), or guanine nucleotide dissociation inhibitors (GDIs). Our main interest is focused on Cdc42 GTPase-activating protein (CdGAP), also called ARHGAP31, a negative regulator of the GTPases Rac1 and Cdc42. Protein acetylation is a post-translational modification that involves the transfer of an acetyl group from acetyl coenzyme A to a specific site on a peptide. Lysine acetylation is predominantly known, but not restricted to, …  Read more

La migration cellulaire est un processus biologique fondamental qui peut se dérouler selon différents modes, notamment par l’intermédiaire d’adhésions intégrines, structures dynamiques reliant la matrice extracellulaire au cytosquelette d’actine. paxillin, une protéine adaptatrice centrale des adhésions focales, joue un rôle essentiel dans la coordination du signalement cytosquelettique au cours de la migration. Cependant, les conséquences de sa perte complète et la régulation spécifique exercée par la phosphorylation de la focal adhésion kinase (FAK) et de la p21-activated kinase (PAK) à leurs sites cibles précis demeurent mal comprises.Afin de disséquer le rôle de la phosphorylation de paxillin par FAK et PAK …  Read more

Thanassoulis, George (Supervisor2)  Read more

In trying to solve nonlinear partial differential equations with time dependence using the Galerkin method, one ends up with solving nonlinear systems of ordinary differential equations, which are not easily solved. In this thesis we introduce a new iterative method based on eigenfunction expansion to deal with the finite non-linear systems sequentially. We apply the new method to integrate the semi-linear parabolic equation ut=12u+fu ,x∈D with homogeneous Dirichlet or Robin boundary conditions. We prove the convergence of the new iterative method, and use it to find the multiple solutions of the system, which are difficult to obtain using the Galerkin …  Read more

Antoniou, John (Supervisor2)  Read more

Psaromiligkos, Ioannis (Supervisor2)  Read more

Emami, Elham (Internal/Cosupervisor2)  Read more

Crawford, John E. (Supervisor2)  Read more

Myelin basic protein (MBP) is a key myelin protein that also is expressed during tooth development. Here, the impact of Mbp mutations on tooth development, especially on the mineralization stage, was investigated using different methods. In the study, two mouse models, including MBP-B6, where the LacZ gene is knocked into the endogenous map locus and the mutant Shiverer (Shi) in which most of the mbp gene is deleted. Micro-computed tomography (Micro ct.) scan was used to detect the effect of the MBP gene mutations on the volume and the density of the 1st and 2nd molar. Moreover, radiography was performed …  Read more

Two chromosomal regions, 5q31 and 17q21, are both among the best replicated asthma-associated regions from genome-wide association studies (GWAS) and share certain characteristics.They are among the highest genome-wide significance allele-specific expression differences: in the 17q region, the childhood asthma-associated allele shows increased expression of gasdermin B (GSDMB) and ORMDL sphingolipid biosynthesis regulator 3 (ORMDL3) genes and in the 5q31 region the asthma-associated allele shows increased expression of the solute carrier family 22 (organic 3 cation/carnitine transporter) member 5 (SLC22A5) genes. This suggests that cis-regulatory mechanisms may influence disease development in these regions. Among children, the prevalence of asthma is higher …  Read more

Barralet, Jake (Supervisor1)  Read more

Quantitative analysis of Drosophila melanogaster gap gene expression data reveals valuable information about the nature and strengths of interactions in the gap gene network. We first explore different models for fitting the spatiotemporal gene expression data of Drosophila gap gene system and validate our results by computational analysis and comparison with the existing literature. A fundamental problem in systems biology is to associate these results with the inherent cause of gene regulation, namely the binding of the transcription factors (TF) to their respective binding sites. In order to relate these expression-based estimates of gap gene regulation with the sequence-based information …  Read more

L'amplitude des mouvements de la colonne lombaire (ou ROM, pour range of motion en anglais) est traditionnellement mesurée à l'aide de multiples mouvements individuels exécutés sur les plans anatomiques. La technique utilisée pour obtenir cette mesure complique la recherche clinique, car elle repose sur l'hypothèse qu'une forte proportion de sujets présente la même déficience. L'objectif de cette thèse était donc d'évaluer la fiabilité d'une nouvelle mesure de mouvement global de la colonne lombaire, qui serait utilisée dans des études futures. Notre étude repose sur l'hypothèse que la fiabilité de cette mesure serait ≥ 0,9; de manière à répondre à des …  Read more

Mayo, Nancy (Supervisor2)  Read more

ABSTRACTThis dissertation analyzes Saudi women’s creative expressions of protest in a number of genres: poetry, novels, memoir, blogs, interviews, videos, and the social media platform Twitter. The aim of this dissertation is to fill the glaring gaps in scholarship about Saudi women, specifically in areas of protesting and social change. I challenge the common or mainstream understanding of what it means to protest and how it fits both into Saudi women’s lexicon and social contexts, specifically I attempt to expand the definition of “protest” to encompass Saudi women’s realities. To place Saudi Arabian feminist protest in a theoretical framework, I …  Read more

Cette thèse explore l’interaction complexe entre le capital, l’idéologie et l’environnement bâti, en se concentrant sur le paysage urbain de la Turquie. La trajectoire d’urbanisation de la Turquie a été profondément influencée par la convergence de l’islamisme (ou l’islam politique) et du néolibéralisme depuis la fin du vingtième siècle. Dans ce contexte, Başakşehir, une ville satellite située à la périphérie nord-ouest d’Istanbul, constitue un site exceptionnel pour examiner les expérimentations spatiales de l’islamisme à différentes échelles. Cette recherche considère cet établissement comme une ville modèle, montrant comment l’idéologie fondée sur la foi et les réseaux de capitaux se sont associés …  Read more

Dental implants are a successful and predictable treatment for partially and fully edentulous patients. However, they require sufficient volume of healthy bone for stabilization and long-term success. Lack of bone volume prevents implant placement and it is usually due to many reasons such as tooth loss, trauma or diseases. A variety of surgical techniques are available for alveolar bone rehabilitation. However, bone onlay augmentation is the most reliable and commonly used one. Different bone grafts can be used for bone onlay augmentation. Autograft onlays are currently the gold standard onlay grafts because of their osteoinductive, osteoconductive, and osteogenic properties. However, …  Read more

Extensive emphasis on selection for milk yield with minimal attention to the animals' functional performance has increased the yield of North American dairy cattle. The high intensity of selection for production traits such as milk yield, protein yield and fat yield has also brought about a rapid increase in genetic relationships among animals. In dairy cattle, correlated response to selection for milk yield includes fertility and susceptibility to diseases. Although the high producing cows have greater net profit, they also have higher mammary and discarded milk costs associated with high production. Long-term genetic selection against clinically diagnosed diseases might be …  Read more

GABAergic interneurons comprise only a small minority of total cells in the CA1 region of the hippocampus, yet they are crucial for hippocampal functioning. Investigating the role of these interneurons is necessary to understand hippocampal network mechanisms involved in the formation of spatial navigation reference memories, the primary role of the dorsal hippocampus.Notably, Oriens-Lacunosum Moleculare (OLM) cells, a subclass of somatostatin-expressing (SOM+) hippocampal interneurons, play a unique role in the regulation of CA1 glutamatergic principal cell (PC) input. They can regulate information flow to CA1 PCs from both the entorhinal cortex (EC) and the CA3 region of the hippocampus. Conversely, …  Read more

Les hydrates gazeux, aussi connus comme des «clathrates d'hydrate », sont des complexes crystallins non-stœchiométriques ayant l'apparence de la glace, mais composés d'une structure différente. Ils se forment quand des molécules d'eau se lient grâce aux liens hydrogène pour former des cavités qui peuvent être occupés par un gaz ou un liquide volatil. L'introduction de ces molécules «invités» stabilise la structure formée par les molécules d'eau. Les hydrates sont une nuisance pour l'industrie de développement de gaz parce qu'ils peuvent obstruer les pipelines et équipements, ce qui interromperait les opérations quotidiennes et ajouterait aux coûts de maintenance. Dans cette étude, …  Read more

Three new quantitative Fourier transform infrared (FTIR) spectroscopic methods were developed for the analysis of edible oils: two procedures to measure free fatty acids (FFA) and one to measure moisture (H2O), the latter two methods ultimately being automated and implemented on an auto-sampler equipped FTIR spectrometer. The methods developed for FFA determination both convert FFAs to their carboxylate salts by means of acid/base reaction without causing oil saponification, one approach using 1-propanol, an oil-miscible solvent, and the other using methanol, an oil-immiscible solvent into which the FFA salts are extracted. The first method involves splitting oil samples into two halves, …  Read more

Jorgensen, Jan J (Supervisor2)  Read more