McGill University Thèses et mémoires par auteur commençant par O

Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated transcription factor which controls adipogenesis, fatty acid storage and glucose metabolism. Interestingly, PPARγ agonists lower blood pressure (BP) and improve vascular injury in hypertensive rodents and humans through effects which extend beyond metabolic changes. The mechanism by which PPARγ exerts its vascular protective effects is still unclear and studies investigating PPARγ's direct role in the vasculature are needed. Endothelin (ET)-1, a potent vasoconstrictor peptide produced by the endothelium, plays an important role in the pathophysiology of hypertension (HTN) by causing damage to blood vessels. Transgenic mice overexpressing ET-1 selectively in the endothelium …  Read more

Ubiquitin is a highly conserved 8 kDa protein whose many cellular functions are mediated by its covalent ligation to other proteins. Conjugation of ubiquitin is a multistep process involving a ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzymes (UBCs or E2s), and ubiquitin protein ligases (E3s). The multi-ubiquitination of substrates marks them for degradation by the 26S proteasome. Previously, rat UBC4 isoforms homologous to S. cerevisiae UBC4/UBC5 were cloned and characterized (Wing and Jain, 1995) (Wing et al., 1996). The UBC4-1 isoform is highly expressed in the testis, and the UBC4-testis isoform is induced in round spermatids. This thesis describes the identification and …  Read more

In many sub-tropical and tropical and regions of the world, marly soils (marls) and lime or cement stabilization of marl soils are used as a convenient and expedient means for development of foundation base courses and inexpensive wearing courses for transport purposes. The failure of many of these natural and stabilized marls to perform their function have been reported. This study uses physico-chemical (reaction) factors to explain the general basic causes for deterioration of the support capability for these types of soil. The presence of palygorskite and sepiolite in marl soils provides it with some very unique features in its …  Read more

Aim: Regular repeating patterns are prominent features in a visual scene. Here I consider whether regularity is an adaptable feature that produces a subsequent after-effect and whether a first- or second-order process mediates that after-effect. Method: Stimuli consisted of a 7 by 7 arrangement of elements on a baseline grid. The position of each element was randomly jittered from its baseline position by an amount that determined its degree of pattern irregularity. The elements of the pattern consisted of dark Gaussian blobs (GB), difference of Gaussians (DOG) or random binary patterns (RBP). Observers adapted for 60 seconds to a pair …  Read more

An important part of our understanding of human vision comes from the study of ambiguous figures, a sub-set of which include bi-stable figures, such as the well- known Necker cube, and binocularly rivalrous figures. Key insights into the mechanisms of ambiguous figure perception have come from studying the effects of context on their variable perceptual interpretations. Since a given context tends to result in a predominance of one perceptual interpretation over the other, contextual influences are instructive for our understanding of the process of perceptual binding. In three studies I explore the effects of spatial context on the properties of …  Read more

Phase 2 clinical trials represent the first time a new cancer treatment is tested for efficacy in patients. They outnumber all other phases and require substantial healthcare and research resources. They are vital in bridging basic research and clinical practice. However, because they deliver active doses of a yet unproven drug, they present challenges for risk and benefit. The aim of this thesis was to examine the balance of risks and benefits faced by patients enrolling in phase 2 cancer trials and to resolve the precise ethical justification for exposing patients to unproven treatments in such trials. Chapter 1 assessed …  Read more

Background: Major codes of human research call for minimizing patient burden and maximizing knowledge gains. Some research activities may make better use of patients because their findings have a greater impact on care. In this report, we use a metric of efficiency, the number of patients needed to achieve an FDA approval, to estimate the impact of post-approval research compared to initial drug development that required 12,217 patients.Methods: We created a sample of anti-cancer drugs approved by the FDA between 2012 to 2015. We searched clinicaltrials.gov to identify drug development trajectories launched after FDA approval. We identified the number of …  Read more

Beluga is a functional programming language and proof assistant for specifying formal systems in contextual LF, an extension of the Edinburgh Logical Framework, and mechanically proving theorems about them using recursive programs.To facilitate the incremental development of proofs with commands and automation tactics, the Harpoon interactive proof environment is subsequently implemented as a read-eval-print loop with structural editing features over Beluga programs.Due to architectural limitations in the implementation of Beluga and Harpoon, top-down and out-of-order proof development sessions can lead to invalid proof states and unsound translated programs.This thesis reports on technical challenges and solutions to soundly implementing the structural …  Read more

The purpose of this study was to investigate the results of two long-term fertilization experiments on soil organic C, total N, and mineralizable N in the Jiangsu Province of People's Republic of China. The soil samples that received manure over the years contained more soil organic C, and total N than the inorganic fertilized samples. Soil organic C was closely correlated with total N and there were correlations between crop yields and soil organic C contents and between crop yields and soil total N contents. Plant-available N was estimated using biological and chemical tests. Mineralized N formed under anaerobic incubation …  Read more

It is not many years since all metals were regarded as the personal property of the feudal lord of the region in which they were found, no matter what rights the lord may have granted for the use of the surface. This idea of sovereignty still exists in many countries and as both gold and silver when coined become currency, the manufacture of currency has always been considered a state monopoly, and mines bearing, gold and silver have been termed royal mines and considered as belonging to the sovereign.  Read more

Shaw, Steven (Supervisor2)  Read more

La relation entre les gestes non-verbaux et les capacités linguistiques a été investiguée chez 18 enfants atteints d'autisme et 28 enfants avec le syndrome de suppression 22q13. Les objectifs de cette étude étaient d'examiner si les enfants avec l'autisme et le syndrome de suppression 22q13 ont des modèles d'associations semblables entre les gestes non-verbaux et les capacités linguistiques réceptives et expressives. De plus, il y eu une investigation pour connaitre quels types de gestes non-verbaux étaient le plus significatif pour prédire les capacités linguistiques. Les résultats ont démontré que le modèle d'association entre les gestes non-verbaux et le langage diffère …  Read more

La relation entre les gestes non-verbaux et les capacités linguistiques a été investiguée chez 18 enfants atteints d'autisme et 28 enfants avec le syndrome de suppression 22q13. Les objectifs de cette étude étaient d'examiner si les enfants avec l'autisme et le syndrome de suppression 22q13 ont des modèles d'associations semblables entre les gestes non-verbaux et les capacités linguistiques réceptives et expressives. De plus, il y eu une investigation pour connaitre quels types de gestes non-verbaux étaient le plus significatif pour prédire les capacités linguistiques. Les résultats ont démontré que le modèle d'association entre les gestes non-verbaux et le langage diffère …  Read more

Cavity ring-down spectroscopy (CRDS) is a novel, accurate, sensitive and non-intrusive laser-based technique using multiple-paths molecular absorption to measure weak absolute concentrations of atoms or molecules (ppm range or better). In CRDS, a laser pulse is coupled into an optical cavity equipped of highly reflective mirrors mounted at both ends and containing the absorbing medium. The laser pulse experiences numerous round trips inside the cavity thus considerably increasing the absorption path. The decay of the laser pulse intensity leaking out of one of the cavity mirrors is monitored in real-time and the concentration of the species is obtained by fitting …  Read more

Cette thèse consiste principalement en un article récemment soumis pour publication qui classifie les puzzles à anneaux impairs associés aux complexes de Moebius–Kantor--chapitre 2, accompagné d'une courte introduction au sujet--chapitre 1. L'article a été réalisé en collaboration avec Mikaël Pichot et Sylvain Barré. Les puzzles à anneaux sont des pavages du plan euclidien satisfaisant des contraintes locales autour des sommets, obtenus comme solutions à un problème de puzzle à anneaux. Ceux-ci peuvent apparaître en théorie géométrique des groupes, par exemple, sous-forme de plats plongés dans certains complexes CAT(0) de dimension 2. En général, il n'est pas évident que des solutions …  Read more

Gao, Zu-hua (Supervisor2)  Read more

New digital communication applications, such as multimedia, require very powerful error correcting codes that deliver low error rates while operating at low to moderate ratios (SNRs). Turbo codes have reasonable complexity and can achieve very low error rates if a proper interleaver design is in place. The use of well-designed interleavers result in very low error rates, especially for medium to long interleavers where turbo codes offer the greatest potential for achieving high minimum distance (d min) values. The reliable determination of a code's error performance at very low error rates using simulations may take months or may not be …  Read more

Dans cette thèse, nous présentons deux solutions intégrées pour mesurer les fluctuations dans le timing des signaux numériques, communément appelé “jitter”, et ce dans les systèmes sur puce et les systèmes d'acquisition de données (principalement les CANs). Ces techniques sont aussi employables dans toutes autres applications métrologiques dont le principe de fonctionnement est basé sur la mesure du temps.La première méthode est basée sur l'amplification de la différence de temps à mesurer à l'aide d'un amplificateur de temps (TAMP). Le résultat de l'amplification est ensuite numérisé en utilisant un convertisseur temps-numérique. La conception de l'amplificateur est basé sur le principe …  Read more

We present a practical yet accurate approach for dealing with the problem of inserting repeaters along on-chip interconnect lines to meet delay and transition time requirements. This approach is based on the fact that the transition time and the delay at the far end of an interconnect segment are, respectively, independent and linearly dependent on the driving repeater's input transition time, as long as the ratio of the output to input transition time does not exceed a pre-defined value. In this context, we first derive simple closed form expressions for the optimal repeater spacing and sizing. Then, we propose a …  Read more

The teaching of geography in Canadian universities and its application to public affairs at all levels of government have increased remarkably in the last decade. As Canadian scientists, economists and historians paid more and more attention to the geographical factor in the growth of the nation, courses of instruction in geography were introduced into the Arts curriculum. This began in Toronto in 1906 and then at the University of Montreal in 1910. The University of British Columbia, in the twenties, and McMaster and Western Ontario Universities, in the thirties, followed suit and the ground-work was laid for wartime and post-war …  Read more

Twenty-seven fertilizer treatments with celery were set out in duplicate on muck soil on 1/57.6 acre plots. The yields were recorded by weight, and analysed by the analysis of variance. Nitrogen, phosphorus and potash all gave very significant increases over the nil treatment. Doubling the phosphorus and potash in the basic treatment resulted in further increments in yield. Celery was grown in quartz sand in the greenhouse and nutrients approximating the fertilizers used in the field were applied as nutrient solutions. The effect of nitrogen, phosphorus and potash on the growth of tops and roots and on the number of …  Read more

Nous consid ́erons le problème de suivre une personne avec une drone aérien. Nousposons le problème comme une version du problème de poursuite-évasion (PE) avecles obstacles non-param ́etriques, tels que ceux dans les grilles d’occupation. Noussupposons que l'évadeur n’est ni collaboratif, ni compétitif, mais qu’il va suivre unetrajectoire qui n’est pas connu a priori par le poursuivant. En conséquence, on con-sidère la performance moyenne-cas plutôt que des limites de performance supérieureet inférieure, et proposons un algorithme probabiliste. Contrairement à certainesvariantes de PE, le jeu ne se termine pas si il ya une occlusion, nous permettons ainsile poursuivant de ratrapper l'évadeur.A …  Read more

Free braided pivotal categories are equivalent to free strict monoidal categories on a graph with relations. This is important in the study of knot invariants in that new invariants can be constructed simply by finding suitable strict monoidal categories. This is demonstrated by developing the formal language of strict monoidal categories on a graph with relations, creating categories with relations corresponding to the Reidemeister moves of knot theory and finally showing that these categories are in fact free braided pivotal categories and further equivalent to the categories of link diagrams from knot theory.  Read more

Myelin and axonal debris are cleared very slowly after injury to the adult mammalian central nervous system (CNS). This process of degeneration distal to the site of axon injury, called Wallerian degeneration, can take several weeks to months to complete in the CNS, and is thought to be due to a slow immune cell response. However, rapid myelin phagocytosis can occur in the CNS under certain conditions such as during lysophosphatidylcholine (LPC)-induced demyelination. To understand the factors that regulate and control the immune cell responses that lead to rapid myelin phagocytosis, I first studied the cellular and molecular changes that …  Read more

Bernard, Daniel (Supervisor1)  Read more

This is a study of the vestibulo-ocular and vestibulo-collic reflexes, two neuromuscular control systems providing velocity stabilization of eye and head respectively, relative to space. As well as having a common role in visual image stabilization, the two systems share the same angular velocity sensor, the semicircular canal, and the responses of both are complicated by the occurrence of saccades, or quick re-positioning flicks which permit intermittent velocity stabilization (between flicks), even during movements whose amplitude exceeds the limits of eye or head excursion respectively. In the vestibulo-collic system further complexity arises because of direct mechanical feedback of the canal …  Read more

Des chercheurs modernes ont démontré de manière décisive qu'au Moyen Âge, il n'existait aucune séparation distincte entre la religion et la médecine, mais la véritable importance de ce lien reste à découvrir. Nulle part ailleurs les nuances de la relation entre la religion et la médecine ne se sont présentées plus clairement que dans la tradition du Christ médecin divin, le Christus medicus. Le Christ le médecin divin est né d'une allégorie des Évangiles synoptiques, sa Passion symbolisant les moyens de canaliser la souffrance en processus de guérison. Cependant, le Christus medicus était plus qu'une allégorie. Il avait un impact …  Read more

Les nanomatériaux de basses dimensions aux propriétés électroniques accordables sont appelés à jouer un rôle essentiel dans la conception de dispositifs nanoélectroniques de nouvelle génération. Dans la présente étude, trois méthodes de contrôle des états électroniques ont été étudiées, à savoir la régulation des défauts cristallins, le contrôle des contraintes mécaniques ainsi que la conception d'hétérostructures. La théorie de la fonctionnelle de la densité (DFT), alliée à la méthode NEB, a été utilisée pour scruter les propriétés électroniques et la dynamique des défauts dans ces nanomatériaux bidimensionnels. Les défauts cristallins dans les nanomatériaux bidimensionnels peuvent être à l'origine de niveaux …  Read more

De par l'étude de l'isomorphisme au sein des dichalcogénures de métaux de transitions (TMDs), il est urgent d'appréhender les mécanismes de transition de phases potentielles, ainsi que de leurs applications. Dans cette thèse, afin de proposer une compréhension théorique de l'ingénierie des phases, des calculs numériques par théorie de la fonctionnelle de la densité (DFT) sont exécutés à l'aide de modèles continus tel que la théorie des phonons, des mécanismes d'élasticité, etc. Cette thèse couvre la thermodynamique de transition de phase, l'optimisation des techniques d'ingénierie des phases ainsi que des applications à partir de transformations de phases contrôlables.Pour commencer, les …  Read more

Urea and triple superphosphate (TSP) are important N and P fertilizers, respectively, but they suffer from inefficiency because of NH$ sb3$ volatilization and phytotoxicity and P fixation. Combinations of urea and TSP or KCl might improve N and P use efficiency primarily through pH changes. Mixtures of urea, TSP and KCl, either compacted or blended, were studied as to NH$ sb3$ volatilization, denitrification and P transformation in soils, and N and P use efficiency in crops. Soils studied included a Ste. Rosalie clay (Humic Gleysol), an Ormstown silty clay loam (Humic Gleysol), a Chicot sandy clay loam (Grey Browm Luvisol), …  Read more

Design is concerned with the question of how to construct an artifact or system to meet the desired specification and is normally categorized as either routine, non-routine or creative. Up until now, the study of knowledge-based design has concentrated on routine or non-routine design. In order to explore creativity in design, a new computational model based on the combination of case based reasoning (an approach to solving new problems based on the solutions of similar past problems) and soft computing techniques (such as machine learning, data mining and optimization), is proposed in this thesis. The new model is able to …  Read more

We present a framework of specularity pattern to interpret the interaction between specularities and short-wave specular planes as well as light sources at infinity. The specularity on a short-wave plane is treated as a special kind of texture (specularity pattern) mapping on a flat carrier plane. This concept of specularity pattern acts as an intermediate layer between the 3D scene setting and the 2D image of the scene. Under the framework of specularity pattern, the information on specularities is divided into two parts, appearance and statistics. The appearance provides a texture for mapping to invoke impression of specularities. The statistics …  Read more

Cet ouvrage examine les motifs inhérents à la compréhension de la nature du fruit défendu en tentant de démontrer des parallèles entre le raisonnement des interprètes bibliques d'un côté, et celui des artistes de l'autre. Alors que le texte biblique de la Genèse 2:16-17 offre une représentation abstraite en employant vaguement le mot «fruit», les représentations visuelles, elles, présentent inévitablement une image plus concrète et moins générique en illustrant un fruit spécifique. Ma recherche présente ce phénomène d'abstraction et de concrétisation à travers cinq chapitres qui manifestent la juxtaposition entre le texte biblique et son illustration: en premier, la représentation …  Read more

Contexte et objectifs: Les analgésiques en vente libre, y compris les anti-inflammatoires non stéroïdiens et les corticostéroïdes comme la dexaméthasone, sont couramment utilisés après une blessure. Cependant, des recherches récentes suggèrent que leur utilisation répandue peut supprimer la réponse inflammatoire lors de la douleur aiguë, augmentant involontairement le risque de développer des affections chroniques. Nous avons émis l'hypothèse que l'utilisation de sérum conditionné (CS), qui représente une activation physiologique contrôlée de la réponse immunitaire, pourrait être une approche thérapeutique plus efficace contre la douleur chronique que l'inhibition de l'inflammation.Méthodes: Navons examiné l'effet du sérum conditionné dans deux modèles de douleur …  Read more

Although the action of the Grignard reagent on anthrone and anthraquinone has been known for many years, it is only recently that any study has been made of its reaction with benzanthrone. The published work presents conflicting evidence. [...]  Read more

Seguin, Philippe (Internal/Cosupervisor2)  Read more

Bertrand Russell, the man who was to become the most outspoken and best known philosopher of the first half of the twentieth century, was born in England in 1873, the second son of Lord and Lady Amberley. He knew little of his parents for, when only two years old, both parents died within a year leaving as orphans Bertrand and an older brother, Frank. Russell's life for the next sixteen years was to be spent in the home of his grandparents, Lord and Lady Russell. [...]  Read more

Le comportement d'un thérapeute peut influencer le succès du processus thérapeutique des patients. Cette étude vise à examiner si deux aspects comportementaux de stagiaires thérapeutes –les compétences interpersonnelles et les modes de réponse verbaux (VRM) –ont influencé les processus de la thérapie. Les compétences interpersonnelles et les VRM des stagiaires ont été comparés par intervalle de deux minutes précédant soit les niveaux de l'approfondissement de l'expérience émotionnelle du client (N = 30), soit les niveaux d'expérience émotionnelle invariables (N = 30). Les résultats ne montrent pas de relation entre les compétences interpersonnelles et les VRM, ni selon l'expérience émotionnelle du …  Read more

Dans le but d'améliorer l'issue des traitements prodigués, le domaine de la psychothérapie a de plus en plus adopté un modèle de pratique fondée sur des données probantes (PFDB). Le suivi systématique de l'évolution du patient constitue un élément clé de la PDFP. Le présent mémoire porte sur une méthode de suivi bien précise qui a reçu un fort soutien dans les documents de recherche: le suivi des progrès (SP). Le présent mémoire vise deux objectifs : (a) déterminer l'emploi des méthodes de SP aux sites de formation à l'échelle de l'Amérique du Nord; (b) décrire les facteurs qui viennent …  Read more

Cognition shapes the interactions of an animal with its environment. Species vary greatly in all aspects of cognition, and studying the relationship between this variation and ecology is crucial for understanding how intelligence has evolved. In this thesis, I approach questions about the ecology and evolution of cognition that are often ignored because cognition is difficult to quantify. I use innovation rate as an operational measure and residual brain size as a correlate of general cognition in birds. I first examine the link between cognition and ecology through comparative analyses of the relationships between residual brain size, innovativeness, and measures …  Read more

It is well known that a response learned by an animal in its normal state may be markedly depressed when any one of a number of drugs is administered to the animal. Such drug effects are currently receiving considerable attention. A different type of drug effect is that first noted by Girden and Culler (1937). They observed that, in certain cases, a response learned in a particular drug state would subsequently reoccur only when that drug state was reinstated. Their results draw attention to response decrements produced by a change in the chemical state of the organism, independent of whether …  Read more

dsc-4(qm182), a mutation that suppresses the lengthened defecation cycle of clk-1 also suppresses the delay in germline development. dsc-4 encodes a putative orthologue of microsomal triglyceride transfer protein (MTP), a protein essential for the assembly and secretion of apo-B-containing low density lipoproteins (LDL). The effect of dsc-4 on clk-1(qm30), coupled to studies of apoB homologues in worms led to a model suggesting the possibility of using C. elegans in the study of LDL-like lipoprotein particles. The impact of the level of lipoproteins is particularly evident in the germline developmental rate of the worms. We report here a further elucidation of …  Read more

Cette thèse étudie la représentation symbolique des problèmes sociaux et politiques contemporains dans trois téléfictions historiques, La Pola, amar la hizo libre (Colombie), Martín Rivas, aventuras de un soñador (Chili) et Lo que El tiempo nos dejó (Argentine), toutes diffusées pendant le Bicentenaire de l’Indépendance en 2010 dans chacun de ces pays. J’analyse comment ces fictions télévisées jouent le rôle de médiateurs entre les préoccupations et les valeurs culturelles du citoyen actuel, comment leur contexte de production influence la fiction historique et quelles sont les implications idéologiques et politiques qui en résultent.Sur la base des études théoriques concernant le mélodrame …  Read more

This dissertation comprises three essays that study three distinct derivative contracts. The first essay proves, in a model-free framework, that early exercise of futures-style options on futures, whether calls or puts, is suboptimal. The result is robust to transaction costs, liquidity constraints and collateral requirements. Assuming a frictionless market, three additional model-free results are obtained: (i) put-call parity, (ii) equality of time values of puts and calls with the same strike and expiration, and (iii) positivity of time value before expiration. The second essay develops a new invoice price formula for Treasury bond futures contracts as a more effective alternative …  Read more

It is estimated that more than 55 million people live with a diverse array of diseases that are considered rare. Because of the rarity, little is known about its impact on a child’s life. Families of children with rare diseases are concerned with not having sufficient information about the disease course, treatment options and outcomes. Apart from survival, families are most concerned about the child’s quality of life (QOL). A key challenge is a lack of condition specific QOL measures to quantify the impact of treatment and disease. Instead, generic measures of health-related quality of life (HRQL) are used to …  Read more

Le cancer du poumon demeure la principale cause de décès de tous les cancers au Canada. On estime que 20,000 Canadiens mourront du cancer de poumon chaque année. Le cancer du poumon non à petites cellules (CPNPC) représente la majorité des cas de cancer du poumon et est associé à une survie de 5 ans dans 10 à 20% des cas. L'échec local dans les patients atteints du CPNPC représente un problème majeur après un traitement de chimio-radiothérapie et est un indicateur de développement de métastases à distance. La radiothérapie stéréotaxique ablatif (SABR) est une forme technologiquement avancée de délivrer …  Read more

Marino, Faleh Tamimi (Supervisor1)  Read more

This work treats freeudom of opinion ln France and-Canada. Freedom of assembly; freedom of expression, by such means as speech, press, radio, theatre and cinema; and freedom of association,for trade unions as weIl as polltlcal groups; are compared in the two countries. The conclusion based on this comparative study Is that there is much more freedom of opinion in France than in Canada and that the latter would do weIl to respect in a like manner the principles essential to a free expression of opinions.[...]  Read more