McGill University Thèses et mémoires par auteur commençant par B

Le développement d'outils efficaces pour la caractérisation des propriétés mécaniques des tissus mous est nécessaire. La connaissance du module d'Young et du coefficient de Poisson est essentielle à la modélisation du comportement mécanique et à l'estimation des champs de contraintes et de déplacements. L'objectif de cette étude est de mettre en oeuvre une méthode indirecte permet- tant d'identifier les constantes de matériau de tissus mous à partir de données expérimentales, pour des échantillons de forme et de composition variables. L'approche retenue est la résolution d'un problème inverse sur-déterminé. Des simulations par éléments finis en trois dimensions ont été réalisées, modélisant …  Read more

OBJECTIF: Mettre à l'épreuve l'hypothèse que le modèle de Fitts et Posner en apprentissage de la motricité contribue à l'amélioration de l'habilité motrice autonome. Pour ce faire, nous avons évalué l'automaticité des neurochirurgiens et des résidents séniors et juniors, lors de chirurgies de deux tumeurs identiques qui se sont faites sous la plateforme de réalité virtuelle NeuroVR. MÉTHODE: Pour reproduire un environnement semblable à la pratique actuelle en neurochirurgie, neuf tumeurs simulées identiques, de différente complexité visuelle et haptique, ont été reséquées à deux reprises. Il y a eu un total de 18 résections faites par neuf neurochirurgiens, 10 résidents …  Read more

Evidence is presented which confirms that glucose is a major factor in estrogen loss during hot acid hydrolysis of undiluted human diabetic pregnancy urine. This difficulty can be overcome, for estriol, estrone and estradiol-17x, by diluting the urine with water prior to acid hydrolysis, or by enzyme hydrolysis. [...]  Read more

Monoclonal antibodies (MAbs) have been raised against $ beta$-tubulin of B. pahangi and A. suum. Anti-B. pahangi MAbs were used to investigate the heterogeneity of tubulins from nematodes and mammals. One-dimensional SDS-PAGE showed that MAbs P3D and 1B6 react with $ beta$-tubulin from a number of filarial and intestinal nematodes, but not with tubulin from protozoan and mammalian cells. Two-dimensional SDS-PAGE demonstrated that MAb P3D recognizes two isoforms of $ beta$-tubulin and 1B6 recognizes one. Limited proteolysis showed that MAb 1B6 reacted with the amino-terminal fragments and MAb P3D with the carboxyl-terminal fragments of $ beta$-tubulin. The effect of anti-B. …  Read more

Benedicto, Roberto (Supervisor2)  Read more

FPGAs have been among the fastest growing segments of the semiconductor industry and this growth is expected to continue over the next several years. The complexity of FPGAs makes manual designs time consuming and error prone; design automation tools are essential to the effective use of FPGAs. Routing is one part of the design process of VLSI chips that is computational complex and hence very time consuming. The arrival of the interior-point method proposed by N. Karmarkar was an important event in linear programming and several variants have been developed since then. Recent experiments in a variety of areas report …  Read more

Lorsqu'ils marchent dans la communauté, les individus doivent contourner des objets et autres piétons. Bien que cette habileté soit souvent compromise chez les populations de patients présentant une incapacité physique, son évaluation et son entraînement en milieu clinique ou en laboratoire demeurent difficiles. La réalité virtuelle (RV) est un outil qui permet de reproduire les conditions de la vie réelle tout en permettant aux personnes de se déplacer dans un environnement sécuritaire et contrôlé. Néanmoins, les évidences démontrant que la RV génère des comportements moteurs naturels sont rares et aucune étude n'a spécifiquement examiné le contournement de piétons dans un …  Read more

Introduction: La marche implique de coordonner une séquence alternée de mouvements des membres inférieurs qui doit être ajustée en fonction des exigences de l’environnement. En milieu communautaire, les piétons utilisent les informations visuelles pour détecter les obstacles et adapter leur locomotion ; toutefois, les dynamiques corticales sous-jacentes à ce comportement restent peu connues. Cette lacune est d’autant plus importante que les troubles neurologiques affectant le cerveau entraînent souvent des difficultés à franchir les obstacles, ce qui augmente les risques de chutes et de blessures. Pour analyser l’environnement et guider l’exécution des ajustements locomoteurs, le cerveau traite les informations visuelles permettant …  Read more

Background: Current nutrition trends indicate that malnutrition and food insecurity are not only a matter of undernutrition but also overnutrition. This nutrition transition not only affects individuals of low income levels, but all corners of the world and individuals of all ages, sexes, and income classes. This is especially important in the middle income class where demands for processed foods are at a high.Objective: To explore the effect of the size of national middle class on global food security, as well as to determine the factors impacting this relationship. Methodology: Data were collected from the 2014 Gallup World Poll cross-sectional …  Read more

An object recognition system called ORB1 is proposed and implemented for use on a mobile robot. ORB utilizes the QUADRIS sensor platform developed at the Centre for Intelligent Machines (CIM) at McGill University, which is composed of two BIRIS2 laser rangefinders. ORB performs a series of sensory and perceptual tasks in conjunction with a mobile robot control architecture called SPOTT. ORB's main task is to sense the mobile robot's surroundings and provide laser range data, in the form of line segments, for SPOTT's map database. In an office environment, ORB also identifies and labels the structural objects (i.e., walls, doors) …  Read more

Hydrated electron (e-aq) dosimetry uses absorption spectrophotometry to monitor the concentration of e-aq, leading to the determination of absorbed dose. This technique has been employed in radiotherapy applications in the high dose-per-pulse regime (~ 10-100 Gy per pulse) for the past 60 years; however, our recent prototype has confirmed its suitability in the low dose-per-pulse regime (< 1 cGy), under clinically relevant beam energies. There were three objectives for the prototype in this study. Firstly, radiochromic film measurements were performed to verify dose results obtained from the prototype. The dose-per-pulse between the EBT3 Gafchromic laminated films and prototype were in …  Read more

The production of phenotypic variation, and the mechanisms underlying it, are of fundamental importance to evolutionary processes, as natural selection acts only upon existing variation. Therefore, understanding the processes and mechanisms that give rise to morphological diversity is critical to evolutionary biology. The study of morphological variation also serves as a gateway to understanding the evolution of biological complexity. In the context of vertebrate animals, the evolution of a complex axial column provides a compelling case study in the development and evolution of biological complexity. The transition from a relatively simple, undifferentiated vertebral column to a complex structure capable of …  Read more

During high frequency stimulation, synaptic efficacy decreases due to the depletion of the readily releasable pool (RRP), and its replenishment is vital in maintaining synaptic transmission. According to the 'mobilization by liberation' model, stimulation and subsequent calcium accumulation frees vesicles from their cytoskeletal constraints, leading to the replenishment of the RRP. Additionally, okadaic acid (a phosphotase inhibitor) and staurosporine (a protein kinase inhibitor) have been shown to affect vesicular mobility. In this thesis, the 'mobilization by liberation' model is tested by evaluating how the dynamics of the vesicular system change with stimulation, calcium, temperature, and compounds which affect vesicular mobility. …  Read more

Sleiman, Hanadi (Supervisor1)  Read more

Modern and ancient sediments are complex biogeochemical systems where multiple sulphur isotopes may be useful in tracing previously unseen processes. Multiple sulphur isotope signatures of pore water sulphate from methane-rich marine sediments indicate different microbial pathways involved in the overall sulphur cycling. Particularly in chapter 2, we found that sulphate reduction is the only microbial process controlling the sulphur cycling at station 12 but at station 5 up to 60% of sulphide produced from sulphate reduction re-oxidizes back to sulphate. We are only able to tell this difference with multiple sulphur isotopes. (Chapter 2- Hidden sulphur cycle stimulates the microbial …  Read more

Étant donnée la complexité du cancer du sein, des modèles de souris génétiquement modifiés (GEMMs) ont contribué à la compréhension des bases génétiques et moléculaires de la transformation en tumeur maligne. Les canaux des glandes mammaires sont constitués de cellules épithéliales très organisées pour assurer le maintien de l'homéostasie et l'intégrité architecturale du tissu par deux grandes classes d'adhésion cellulaire : cellule à cellule, et cellule à la matrice extracellulaire (ECM). La dégradation progressive de ces types d'adhésion cellulaires coopère avec l'activation oncogénique ou la perte d'un suppresseur de tumeur pour amener à une transformation maligne. Grâce à l'utilisation de …  Read more

This thesis analyzes the relationship between the exclusivity clauses of the Warsaw and the Montreal Conventions (Warsaw Regime), and the impossibility that these clauses posse upon States to simultaneously comply with some primary obligations under International Human Rights Law (IHRL). A detailed analysis of the core obligations of the IHRL regime would require a research beyond this master thesis; thus, I decided to limit the scope of this research to obligations under two key IHRL treaties: the International Convention on the Elimination of all Forms of Racial Discrimination (CERD) and the Convention on the Rights of Persons with Disabilities (CRPD). …  Read more

A statistical analysis of water quality data collected on paired agricultural watersheds was undertaken. The objective of the study was to evaluate trends in water quality. The data sets that were used to determine the changes in water quality were taken from the project "Gestion de leau dans le bassin versant de la partie superieure du ruisseau St. Esprit". For the period from 1994 to 1996, the analysed water quality parameter were nitrate, phosphate, ammonium, potassium, total Kjeldahl nitrogen, total phosphorus and suspended sediment. The data sets were analysed using descriptive statistics, graphical techniques and non-parametric methods to detect trends …  Read more

The management of natural resources has greatly improved over the past decade. Despite advances in modelling the fate of nutrients or in modelling socio-economic effects of different farm management strategies, tools that integrate the advances made in these fields are still lacking. To develop a tool to overcome this gap, this research focused on the development of a multi-objective decision support system (MODSS) to alleviate phosphorus (P) contamination from agricultural fields and small watersheds. A decision supporting framework was designed to allow technical and public users to run the MODSS. The MODSS consists of the following elements: nonpoint source pollution …  Read more

Gibberella zeae (anamorph: Fusarium graminearum) is the causal agent of fusarium head blight (FHB) and maize ear rot, two major diseases of wheat and corn in Eastern Canada. In Quebec, Microsphaeropsis sp., an antagonist of Venturia inaequalis, the causal agent of apple scab, was isolated from the apple leaf litter. This fungus, well adapted to Quebec climate, can reduce the initial inoculum of V. inaequalis. FHB and Gibberella ear rot are similar to apple scab because the major inoculum source comes from melanized structures produced on crop residues. Consequently, we evaluated the potential of Microsphaeropsis sp. (isolate P130A) to inhibit …  Read more

Depuis leur découverte, les caractéristiques structurelles de l'ADN, incluant ses propriétés de reconnaissance moléculaire, sa synthèse programmable et son assemblage coopératif en double hélice ont grandement inspiré les sciences modernes. Parmi ces disciplines, la nanotechnologie en ADN a évolué au cours des trois précédentes décennies et est devenue une approche accessible qui permet le design et l'assemblage de nanostructures d'ADN bien définies au nanomètre près, pouvant atteindre l'échelle millimétrique et ce, avec un contrôle sans précédent. Sur la base de leurs propriétés, on prévoit que ces objets en ADN pourront être utilisés en bio-détection, en informatique moléculaire, en photosynthèse et …  Read more

Everyone would agree that there is little action in Jacques Poulin's works. This minimalism, which characterizes his writing, is based on solitary individuals who share similar difficulties with social interactions. In Poulin's novels, every interaction seems like an event in itself, as if communicating with others was an adventure. Poulin places the interactions at the heart of his narrative writing. This thesis studies the similarities of these social interactions throughout his eleven novels published to date. The interaction will be analyzed in three phases: as recurring ritual, in connection with the representation of the reader, and with regard to the …  Read more

Les matériaux composites, en particulier, les polymères à fibres de carbone (FC), sont largement utilisés dans l'industrie aérospatiale en raison de leurs propriétés supérieures par rapport à leurs homologues métalliques. Ces structures, éventuellement, subissent des dommages pendant leur fonctionnement en raison de leur longue durée d’opération et de l'environnement hasardeux dans lesquelles elles opèrent. Cependant, restaurer l’intégrité de ces structures composites demeure l’un des principaux défis. Des réparations composites collées in-situ offrent une approche prometteuse pour restaurer l’intégrité d’une structure composite endommagée. Cette technique de réparation est réalisée en faisant polymériser simultanément la pièce de réparation et le film d’adhésif …  Read more

The purpose of the present study was to investigate the extent to which physical education teachers perceive that they use competency-based instruction and to assess some of the factors that influence them to use competency-based instructional strategies. It was also the intent of this study to design the Perceived CBI questionnaire specifically for this study. The results indicated that physical educators did not utilize many of the CBI strategies frequently or all the time. Most evident was the lack of involvement of parents and volunteers in the instructional planning of individualized programs. Also evident was the limited use of the …  Read more

Hydatidiform mole (HM) is an abnormal human pregnancy characterized by the absence of, or abnormal, embryonic development and hydropic degeneration of the chorionic villi. In both Canada and the United States, the incidence of HM is 1 in every 1000 pregnancies. Recently, NLRP7 has been found to be responsible for recurrent hydatidiform moles (RHM) after the identification of various mutations in this gene. To investigate the functional consequences of NLRP7 mutations on IL-1β maturation and secretion, I used site-directed mutagenesis to introduce the various mutations found in patients with RHM into WT-NLRP7. HEK293 cell lines were cotransfected with WT-NLRP7, procaspase-1, …  Read more

This thesis brings a corrective to the secondary literature that addresses women's participation in the Islamic intellectual tradition in premodern Islamic societies. While some studies have discounted the role of women in Islamic intellectual production, other studies have affirmed that large numbers of women obtained advanced training in religious sciences in the premodern era, especially in ḥadīth studies. This latter observation has depended predominately or entirely on positivist readings of ṭabaqāt sources (biographical dictionaries) as historical data. They have noted particular chronological trends in the levels of women's educational participation. Specifically, they have described women's education to be limited from …  Read more

The purpose of this study was to describe the process used to select elementary school principals in Quebec. The results of the study indicated that the majority of school boards do not have written selection policies and procedures to guide the selection of elementary school principals. In addition, the majority of school boards do not have written job descriptions, written selection criteria or written selection techniques. Although there was an absence of written job descriptions, respondents considered educational leadership as the main expectation for elementary school principals. In the absence of written selection criteria, it was noted that respondents had …  Read more

Skeletal development and homeostasis is comprised of complex events characterized by the presence of cell specific regulators and markers. Aberrant expression of any of the regulating factors usually results in metabolic bone disease. Therefore understanding the mechanisms of skeletal homeostasis may disclose new therapies for treating these disorders. While the complete pathway that defines normal osteoblast differentiation remains indeterminate, several regulatory factors have already been identified and characterized. Using gene targeting technology, the importance of parathyroid hormone-related peptide (PTHrP) in skeletal biology has been well established, as PTHrP^-/- and PTHrP^+/- mice demonstrate skeletal abnormalities. Several lines of evidence from in …  Read more

The subject experiment was carried out to investigate the effect of varying the oxygen concentration on flame propagation at elevated preheat temperatures. The experimental runs were made for three oxygen concentrations (.2045, .2320 and .2750 by wt.) at preheat temperatures varying from 293 K to 913 K. It was observed that the blow-off and burning velocities increased considerably with preheat temperature and oxygen concentration increase. Increasing the oxygen concentration increased the flame temperature appreciably.  Read more

The behaviour of electrolytic solutions is to-date not well understood. It is universally accepted that when a solute capable of forming a conducting solution is dissolved in a suitable solvent, it dissociates spontaneously into ions. The phenomena of electrolytic conduction have provided us with the most powerful arguments in favor of this ion concept, but, at the same time have provided much conflicting evidence with regard to the degree of dissociation. [...]  Read more

Zsombor-Murray, Paul J. (Supervisor)  Read more

Acrylamide disc electrophoresis was employed to characterize the isoenzymes of creatine phosphokinase. Three main isoenzyme bands were demonstrated. A specific antiserum against skeletal muscle creatine phosphokinase (CPK) has been obtained. The antiserum was organ rather than species specific. A technique was developed to visualize CPK in precipitin lines. In solution the antiserum inhibited the enzymatic activity of muscle CPK. By means of the immunofluoresence technique, CPK was localized in the intermyofibrillary space of normal human skeletal muscle fibers. A higher concentration of the enzyme was found in fibers which have primarily an anaerobic enzyme profile (type II fibers).  Read more

Ce mémoire examine les relations entre les expériences des enseignantes et enseignantsnoirs avec le racisme envers les Noirs, le racisme institutionnel et la santé mentale dans uncollège en Alberta. Le cadre discursif guidant cette étude décrit les principaux concepts etthéories relatifs au racisme envers les Noirs et la race, et ce, dans un contexte de colonialisme depeuplement. La revue de la littérature synthétise la recherche empirique sur le racisme envers lesNoirs, le racisme et la santé mentale en général, et dans les contextes éducatifs au Canada enparticulier. Sur la base méthodologique de la théorie ancrée, et en conduisant des entrevues …  Read more

Les véhicules aériens sans pilote (UAV) sont de plus en plus proposés pour les tâches de surveillance aérienne, de cartographie et de livraison. Historiquement, ces véhicules se divisent en deux catégories: les aéronefs à voilure fixe conventionnels, qui sont capables de voler efficacement sur de longues distances mais manquent de maniabilité, et les giravions, qui sont capables de voler agilement et manœuvrablement mais manquent de l’efficacité et de l’endurance. Les progrès récents dans la conception des véhicules aériens visent à intégrer les caractéristiques des giravions et des aéronefs à voilure fixe conventionnels, créant enfin des avions capables de voler à …  Read more

Anthropogenic pollution is a growing problem of serious environmental concern. Effects of pollutants are diverse, strongly pollutant-specific, and potentially include modification to the rate at which new mutations arise. Despite theory predicting that stressor-driven modifications of the mutation rate may be important in determining the evolutionary response of populations to stressors, few empirical studies of this phenomenon exist. Further, there are reasons to think mutation rates may generally be evolutionarily optimized within species and buffered from environmental effects. Empirical evidence is particularly lacking in multicellular organisms and this incomplete knowledge likely hinders effective management of wild populations exposed to stressors. …  Read more

Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants that are recognized as global environmental contaminants and a potential health risk. They have been shown to elicit neurodevelopmental toxicity through disruption of the cholinergic neurotransmitter system in rodent models, but the effects of environmentally relevant exposures in wildlife species are unknown. The objective of this study was to assess the effects of the commercial pentabrominated diphenyl ether mixture DE-71 on cholinergic parameters in captive mink (Mustela vison) following dietary exposure of adult females and in utero, lactational and dietary exposure of their offspring. Adult females were fed diets …  Read more

Les oligodendrocytes (OLs) sont les cellules myélinisantes du système nerveux central (SNC). Les OLs matures formant la myéline sont dérivés des précurseurs d'OLs, qui se différencient pendant le développement. La myélinisation engendre la formation de différents domaines axonaux autour des nœuds de Ranvier, zones non-myélinisées de l'axone. Le maintien de ces domaines est essentiel pour la conduction axonale saltatoire, et plusieurs protéines de la myéline contribuent au maintien de la structure et de la fonction de la myéline. La nétrine-1 et son récepteur DCC sont impliqués dans le maintien des jonctions paranodales in vitro, mais leur rôle in vivo n'est …  Read more

Species of the genus Lotus (Leguminosae) are principally located in two geographic areas: the Pacific coast of North America and the Mediterranean region. In addition, endemic species are found in such widely scattered places as South Africa, Australia and Japan. [...]  Read more

The limitations of traditional patient monitoring systems (audio and visual displays) are well-documented and have prompted research into haptic methods for conveying physiological data. Many approaches rely on distributed tactors placed across the body to convey complex information about multiple physiological parameters. This thesis explores a compact haptic-only wearable, which was designed and implemented to deliver heterogeneous tactile feedback through two integrated actuating mechanisms. The device conveys heart rate (HR) and blood pressure (BP) information without relying on visual or auditory channels. Its functionality was evaluated in the context of an experimental study during which we compared participants' performance in …  Read more

At the present time, with coronary disease in such prominence, it is interesting to glance back briefly over the development of our knowledge from the time Heberden first described angina pectoris in England, in 1768, (120). Many well known men have been active in the development of this knowledge. Such names as Fothergill, Hunter, Hammer, Osler, and many others will be familiar to most readers. Hammer, in 1878, was probably the first to diagnose coronary occlusion clinically, and to confirm this diagnosis at autopsy, (117).  Read more

Chez le macaque, le cortex préfrontal, plus spécifiquement la région dorso-latérale 8A, antérieur au sillon arqué et postérieur au sillon principal, serait impliquée dans la génération de comportements dirigés à partir de signaux visuels. Les neurones de cette région démontrent des réponses tant visuelles que saccadiques lors de tâches oculomotrices. Plusieurs tendances relatives à l'encodage spatial sont observables chez les régions impliquées dans les activités visuelles et oculomotrices: les champs récepteurs et champs de mouvements sont organisés de manière rétinotopique, ont une forme Gaussienne et sont proportionnels à l'excentricité. Malgré le fait que ces tendances aient été démontrées dans les …  Read more

Nadeau, Lucie (Supervisor2)  Read more

Cette thèse examine l'opinion du président de la Cour suprême des Etats-Unis, John Marshall, sur l'arrêt _Johnson and Graham's Lessee v. William M'Intosh_ (1823), au regard de l'histoire fictionnelle qu'il employait pour justifier la décision de la Cour. Cette thèse étudie la conception d'Hannah Arendt du mythe et de la légende comme correctif de l'Histoire, et conclut, en accord avec Milner S. Ball, que la transcription légale de la coutume en loi trouve un corollaire naturel dans la licence poétique exercée dans la construction de la préséance de l'obiter dicta. Puisque épopée et loi peuvent être formellement similaires, je soutiens …  Read more

This study's goal is to quantify the influence of large-scale forcing on surface cyclogenesis. This is accomplished by considering seventy surface cyclones, whose maximum deepening occurs in the western North Pacific Ocean. Cyclone classification is based on this pressure change, ranging from +10 to $-$40 hPa/24 h. Composite surface, 850 and 500 hPa analyses for each class, constructed from NMC gridded data are used to diagnose quasi-geostrophic omega and frontogenetical forcing and static stability. Explosive cyclones are distinguished by strong downstream 850 and 500 hPa frontogenesis, suggesting deep baroclinicity's importance during the maximum deepening phase. Cyclogenesis, embedded in a deep, …  Read more