McGill University Thèses et mémoires par auteur commençant par É

Turner, Sarah (Supervisor1)  Read more

Cette thèse est consacrée à l'étude du groupe de Selmer de la réalisation étale p-adique de certains motifs suivant la méthode de Kolyvagin basée sur les systèmes d'Euler.Dans la première partie de cette thèse, nous exploitons le système d'Euler des cycles de Heegner afin de borner le groupe de Selmer associé à une forme modulaire de poids pair différent de 2 tordue par certains caractères d'un corps de classe. Il s'agit d'une extension du travail de Nekovar basée sur l'article de Bertolini et Darmon.Dans la deuxième partie de cette thèse, nous édifions un système d'Euler à partir de cycles de …  Read more

Cybulsky, Andrey V E (Supervisor1)  Read more

Cytoplasmic male sterility (CMS) is a maternally inherited trait of higher plants that can be suppressed by nuclear restorers of fertility ( Rf) genes that normally down-regulate the expression of a CMS-associated mitochondrial gene. In Brassica napus, nap CMS is associated with the expression of the orf222/nad5c/orf2101 mitochondrial gene region and is suppressed by the restorer gene Rfn. I present here an extensive analysis of the expression of the orf222/nad5c/orf2101 region in nap CMS and fertility-restored plants. Using RT-PCR methodology, I mapped transcript initiation sites, processing sites, and 3' termini. I identified two processing events, one within and one immediately …  Read more

The Non-Local Field Theory owe its origin to an attempt made by the physisists to solve the divergence difficulties arising in the Quantum theory of fields. It has often been sugested in recent years that those difficulties could not be solved without modifying the concepts of the conventional field theory for short distances. Since the early days of quantum electrodynamics, it has been clear that an essential part of the divergencies are due to the use of the point-like picture of the elementary particles.  Read more

This thesis presents a new algorithm to compute the probability that a state in a labeled Markov chain model satisfies an LTL specification. A solution to this problem was given by Courcoubetis & Yannakakis in 1995, but unlike their solution the algorithm presented here requires no transformations of the input model. This advantage may be significant because of the large models which occur in most practical verification problems. The new algorithm is proved correct and shown to be not worse than doubly exponential in the size of the formula and cubic in the size of the model. However limited experimental …  Read more

The conjugated diolefinic hydrocarbons have formed the subject of many investigations during the past forty years. This has been on account of the increasing commercial importance of a few such compounds in the manufacture of synthetic rubbers and similar polymers, and the utilization of by-products of the petroleum and coal-tar industries. In this way much information about the properties and reactions of 1,3-butadiene, isoprene, chloroprene, 2,3-dimethylbutadiene-1,3 and 1,4-diphenylbutadiene-1,3 has been accumulated. The subject of this thesis, 2,3-diphenylbutadiene-1,3, has not been studied to any great extent; but, before dealing with this compound in detail, the general reactions of the conjugated dienes …  Read more

La perte d'une seule copie du gène CTCF est retrouvée chez environ 50% des patientes atteintes d'un cancer du sein. Sur la base des données cliniques du TCGA, nous avons émis l'hypothèse que la perte de CTCF pourrait potentialiser l'expression des gènes cible de TP53 chez les patientes. En utilisant les cellules MCF10A comme modèle, nous avons supprimé une seule copie du gène CTCF à l'aide de la technologie CRISPR/Cas9. En utilisant les techniques de qPCR et d’ARN-seq, nous avons découvert que les cellules portant un faible niveau de CTCF affichaient une réponse au gène TP53 améliorée après exposition à …  Read more

Dans la limite appropriée, une configuration de la théorie des cordes de type IIB comportant des D3-branes, des D5-branes enveloppées, ainsi que des flux sur un conifold, mène généralement à une configuration de supergravité impliquant une version voilée du conifold avec des flux. Nous étudions la supergravité duelle de la branche baryonique de la théorie de Klebanov Strassler en rédigeant une métrique de conifold très générique, soit la métrique de conifold voilée-résolue-deformée non Kählérienne, ainsi qu'un ensemble générique de flux qui satisfont les équations de supergravité du mouvement. Sur cette base, nous dérivons les contraintes nécessaires, lesquelles permettront à la …  Read more

Antibiotic use in farming operations can have repercussions when it comes to antibiotic resistant bacteria and to antibiotic residues consumed by the general population. Nitrofurazone is a synthetic broad-spectrum antibiotic of the nitrofuran family that has been banned since the early 1990’s by most regulatory agencies due to increasing evidence of carcinogenicity. Due to the quick metabolism of nitrofurans by host bodies, their detection relies on the analysis of their common metabolites. In the case of nitrofurazone, semicarbazide is used to monitor its use in farm animals. However, it has been shown that SEM can occur due to sources other …  Read more

Les plantes sauvages, généralement non-consommés dans l'alimentation quotidienne, pourraient représenter une grande source d'éléments nutritifs pour les humains; le pourpier est une plante connue comme une mauvaise herbe, il est connu pour avoir une concentration élevée d'acides gras (α-3 and α -6), des composants essentiels pour la santé de l'Homme. L'objectif de cette étude était de déterminer comment l'azote et la photopériode affectent la concentration des acides gras du pourpier, ainsi que la concentration de l'acide oxalique (composant avec un effet légèrement négatif sur la santé de des humains). Neuf accessions de pourpier en provenance du Canada, d'Afghanistan, d'Arabie Saoudite, …  Read more

Rogers, Colin Andrew (Supervisor1)  Read more

Le processus de conception sismiques actuelles pour les structures à Montréal est basé sur l'édition 2005 du Code National du Bâtiment du Canada (CNBC 2005), qui est basé sur un niveau de risque correspondant à une probabilité de dépassement de 2% en 50 ans. Le code est basé sur le spectre uniforme d'aléa (UHS) et a été dérivé par la Commission Géologique du Canada (CGC) avec une version modifiée du logiciel F-RISK. Cette version du code fut développée sans considérer formellement la contribution de l'incertitude épistémique sur l'aléa. Les sources de l'incertitude épistémique sont reliées à la formulation sources sismiques. …  Read more

Suissa, Samy (Supervisor1)  Read more

This dissertation comprises three essays. In the first essay, we provide results for the valuation of European style contingent claims for a large class of specifications of the underlying asset returns. Our valuation results obtain in a discrete time, an infinite state-space setup using the no-arbitrage principle. Our approach allows for general forms of heteroskedasticity in returns. It also allows for conditional non-normal return inno- vations, which is critically important because heteroskedasticity alone does not su¢ ce to capture the option smirk. The resulting risk-neutral return dynamics are from the same family of distributions as the physical return dynamics. Our …  Read more

van de Voort, F. R. (Supervisor)  Read more

Cancer is the leading cause of death in Canada with the head and neck cancer (HNC) ranked seventh in the rate of incidence. More than 90% of HNCs are squamous cell carcinomas (HNSCC) with an overall survival rate of 64.5%. One suggested cause for cancer treatment failure is the limitation of chemotherapy (CT) efficacy by its severe toxic side effects as the conventional treatment will cause damage to non-cancerous cells along with the cancer cells. Thus, reducing the dose of used CT while maintaining its efficiency is critical for improving the treatment outcome of HNSCC. Another possible cause for treatment …  Read more

Compounds of Emerging Concern (CECs) are compounds found in the environment and suspected to cause harm but which are not yet regulated. CECs include a wide variety of compounds including pharmaceuticals, antiandrogens, and estrogens. Recently focus has been on endocrine disruption such as estrogenic and antiandrogenic activity but very few studies analyzed antiandrogenic activity of wastewater and surface water. Antiandrogenic compounds are endocrine disruptors suspected to cause health concerns including male reproduction diseases. Wastewater treatment plants are one of the biggest contributors to CECs environmental release. Previous studies have reported CECs and antiandrogenic activity in WWTP effluents and surface water. …  Read more

This thesis addresses The Development and The Future of English and Islamic Law within the given historical, political, social and legal context of the Sudan. In so doing it uses a comparative methodology. Part I highlights the genesis and the development of Islamic Law in the Sudan over three centuries. Emphasis is on the legal aspect of this long history, though other relevant factors are highlighted as well. The characteristics of this era are significant in understanding later developments of both English and Islamic Law as well as their future in the Sudan. Part II focuses on the factors that …  Read more

Tanguay, Jean-François (Supervisor2)  Read more

Understanding microorganisms' motility provides valuable insight into multiple fields including infectious disease, environmental microbiology, and astrobiology. However, observing microbial motility using conventional light or fluorescence microscopy allows for accurate localisation in two-dimensional (2D) space only, despite the fact that the natural microbial environment exists in three-dimensional (3D) space. Digital Holographic Microscopy (DHM) has recently emerged as a powerful tool for studying microorganisms within their unconstrained 3D space. Unfortunately, this technique suffers from a poor signal-to-noise ratio (SNR), especially when using unlabeled cells (without fluorescent proteins or dyes). Therefore, automatically tracking the bacterial trajectories using image processing and computer vision methods …  Read more

Hearing loss is the third leading chronic disability after arthritis and hypertension, and the most frequent birth defect. Non-invasive diagnoses and middle-ear prostheses are often unsatisfactory, partly because of a lack of understanding of middle-ear mechanics. The focus of this thesis is to develop a 3-D finite-element model to quantify the mechanics of the gerbil middle ear. An MRM dataset with a voxel size of 45 µm, and an x-ray micro-CT dataset with a voxel size of 5 um, supplemented by histological images, are the basis for 3-D reconstruction and finite-element mesh generation. The eardrum model is based on moire …  Read more

The purpose of the work described herein was to investigate the catalytio activity of solid and molten metals, especially in referenoe to the current theories of the structure of oatalyst surfaces. From the consideration of these theories, liquefaction of metallic catalysts should be aooompanied by the disappearance of the "active patches", whether these are regarded as the "active points" postulated by Taylor, or as the crystalline imperfections and the intercrystalline interstices, as assumed by Schwab and others. [...]  Read more

The purpose of the work described herein was to investigate the catalytic activity of molten metals, especially in reference to tte current theories of the structure of catalyst surf8ces. To this end the decomposition of methyl alcohol on zinc was examined by the static method. A study of other reactions on zinc and tin catalysts was attempted. An attempt to investigate the decomposition of ammonia on a liquid silver surface by the flow method was made employing a rotating reaction chamber. [...]  Read more

Au fil des années, l'intelligence artificielle s'intègre de plus en plus dans l'éducation. La génération des questions est un candidat idéal pour une utilisation pratique dans la domaine d'éducation, car les questions sont une intervention pédagogique majeure observée dans l'apprentissage en ligne et en personne. La recherche pédagogique souligne le pouvoir des questions personnalisées pour améliorer la compréhension et les performances des étudiants. Trouver des moyens améliorés d'appliquer et d'adapter la génération de questions personnalisées peuvent créer un outil utile pour améliorer l'expérience de création de contenu d'un enseignant et l'expérience d'apprentissage d'un étudiant.Cette thèse montre que les variantes de …  Read more

Experimental and numerical investigations of laminar natural convection and interfacial heat flux distributions in pure water-ice systems are presented. The main goals are: (i) Resolution of several issues related to steady, two-dimensional, laminar natural convection in pure water near its density inversion temperature; and (ii) development, testing, and demonstration of a nonintrusive experimental/numerical method for the determination of interfacial heat flux distributions in steady, two-dimensional, pure water-ice systems. Attention was found on pure water and water-ice systems contained in a long cylindrical enclosure of square cross-section. One wall was maintained at a constant temperature equal to or less than $0 …  Read more

Muscle function is governed by interactions between actin, myosin, and regulatory proteins, which are the key constituents of striated muscle fibers. Despite extensive research, the understanding of the impact of oxidation on these proteins and the consequent alterations in muscle contraction remains fragmented. As oxidation events play a significant role in aging and various diseases, comprehending these impacts holds a great therapeutic potential. This thesis addresses this gap by providing a comprehensive investigation of the structural and functional impacts of protein oxidation in striated muscles, particularly focusing on myosin-actin interactions. Spanning from the molecular level of amino acids to macroscopic …  Read more

L'atrophie musculaire qui survient avec le vieillissement entraine une perte d'autonomie chez les personnes âgées[1]. Un des composantes menant à l'atrophie musculaire serait une altération des jonctions neuromusculaires (NMJ) [2]. La dénervation qui survient avec le vieillissement induit une fragmentation des récepteurs d'acetylcholine (AChR) affectant la transmission de l'influx nerveux. Ce mécanisme accélère le processus de l'atrophie musculaire lors du vieillissement. L'objectif principal de ce mémoire est d'évaluer les mécanismes sous-jacents au changement des NMJs pendant le vieillissement. Nous émettons l'hypothèse que l'affinité du récepteur kinase specific des muscles (MuSK) est diminuée avec le vieillissement. Afin de vérifier notre hypothèse, …  Read more

Funnell, W. Robert J. (Internal/Supervisor)  Read more

Acute tryptophan (trp) depletion, which purportedly decreases brain serotonin, lowers mood in normal males with a multigenerational family history of major affective disorder (FH+), but not in male controls. In the present study, the hypothesis that a mood lowering response to acute trp depletion may reflect a susceptibility to depression was investigated further. As both a family history of major affective disorder (MAD) and female sex are considered to be risk factors for depression, the effects of trp depletion on mood were investigated in control and FH+ women. The temporal stability of mood change to trp depletion, when rechallenged at …  Read more

This dissertation represents an attempt to better understand why physically abused children are more likely to develop aggressive tendencies. A sample of adolescents receiving child protection services was administered a battery of self-report measures on maltreatment, health, and well-being; an aggression measure was administered a year later. The specific focus was to determine whether aggressive youth were more likely to (1) have suffered harsher physical abuse, (2) generate violence outcome expectancies that favour recourse to aggression, and (3) report higher levels of abuse-related shame. Respectively, the second and third hypotheses were based on social information processing and shame-rage models of …  Read more

The contemporary fine art auction house is a space where aesthetics and commerce merge into a spectacular experience. Sotheby's, London is one example of an auction house turned entertainment space, which masks its blatant capitalist tendencies through the replication of validated cultural institutions. The auction house mimics museum and theatre space in order to create a legitimate social and cultural experience for its clients. Every aspect of the auction event is choreographed to generate demand for its art and an authentic experience for its patrons. Individuals with the approved educational and economical background have access to these constructed locations, and …  Read more

[...] The major part of this thesis is concerned with the preparation and analysis of chromium trioxide oxy-starch, oxy-amylose and oxy-amylopectin. The latter part of the thesis describes a fairly successful attempt to locate the positions of some of the carbonyl groups in the oxystarch by an application of the Kiliani synthesis.  Read more

[...] The determination of amylose and amylopectin in wheat starch is of particular interest to Canadian agriculture and industry. Indeed, the staling of bread may well be attributed to changes in the physical nature of the starch fractions on standing. (19). Hixon has suggested that if a wheat starch containing no amylose was found, the bread from such flours would not be susceptible to staling. More recently, Noznick (34 has presented evidence that bread staling is associated with changes in the amylopectin fraction. A study of the nature of the polysaccharide fractions in wheat starch, their quantitative determination, and of …  Read more

The High Energy Light Isotope eXperiment (HELIX) is a balloon-borne detector, currently in development, to measure the chemical and isotopic abundances of light cosmic-ray nuclei. One of the primary goals is to measure the 10Be/9Be ratio for 0.2-10 GeV/n over two flights. 10Be is a radioactive isotope with a half-life of 1.39 Myr so its abundance, compared to the stable 9Be, constrains cosmic-ray propagation models. HELIX consists of a 1 Tesla superconducting magnet and a drift chamber tracker to measure the particle rigidity. The velocity is measured with a time-of-flight system and a ring-imaging Cherenkov detector (RICH). The RICH radiator …  Read more

Liquid ionization chambers have characteristics that can remedy some of the drawbacks of air-filled ionization chamber dosimetry: large sensitive volumes, fluence perturbations, and energy dependence. However, high ion recombination rates can be a significant problem in liquid chambers. In this work, we have investigated properties of a new liquid chamber, called the GLIC-03 (Guarded Liquid Ionization Chamber), including chamber stability, reproducibility, and establishing recombination corrections. The response varied by less than 1% over 10 hours, and was reproducible within 1.5% of the mean over different liquid fills. Recombination corrections were established, and were small for low dose rates and high …  Read more

Since the discovery of ascorbic acid oxidase by Szent-Gyorgyi (55) in 1931, an ever increasing number of plant species and parts have been shown to contain the enzyme. The following list (Table I) of ascorbic acid oxidase-containing plants has been compiled from the literature up to and including 1950. The list, though small, includes plants from eleven families of the Monocotyledoneae and Dicotyledoneae. Several investigators (16, 20, 55, 62) consider that ascorbic acid oxidase in these plants plays a terminal role in their respiration but others (2, 7), are not in agreement with this view owing mainly to the limited …  Read more

This thesis proposes methods for detection of the appearance, growth, and disappearance of pathology in serial Magnetic Resonance Images (MRIs) of the brain, specifically in the context of new T2-lesion formation and resolution in subjects with Multiple Sclerosis (MS). Detection of appearance and change in pathology in serial MRI is a difficult problem as information from multiple MRI images over multiple timepoints must be considered simultaneously, and MRI images are subject to image artifact that may not be consistent over serial scans of the same subject. The detection of change in pathology becomes a task of differentiating change of interest …  Read more

Potentially large network delay variability experienced by voice packets when travelling over IP networks complicates the design of a robust voice conference bridge. Intrastream synchronization is required at the conference bridge to smooth out network delay jitter on a given stream and provide a continuous stream of voice packets to the conference bridge core. Interstream synchronization is needed to provide time synchronization between packets in different streams, allowing for a mapping of selected voice streams to the conference bridge output and the creation of a periodic and synchronized output from the conference bridge. This work presents a design and evaluation …  Read more

Lella, Joseph (Supervisor)  Read more