McGill University Thèses et mémoires par auteur commençant par B

Avec l’âge, les artères s’épaississent, se calcifient et accumulent de la plaque. Ce remodelage est typique de l’athérosclérose, une maladie inflammatoire causant des lésions artérielles. La dysfonction endothéliale est un élément déclencheur de l’athérosclérose. Les plaques d’athérome peuvent obstruer la circulation sanguine ou se rompre provoquant ainsi de dangereuses complications telles que les crises cardiaques et les accidents vasculaires cérébraux. Elles se trouvent principalement dans les régions de la vasculature ou le flux est turbulent. D’ailleurs les cellules endothéliales (CE) s’alignent sous la contrainte de cisaillement de flux laminaire. Les méthodes actuelles pour étudier le vieillissement vasculaire sont souvent limités …  Read more

La demande croissante pour les terres rares (ETR), en particulier les ETR lourds, a lancé une forte hausse de l'exploration minérale et de la recherche scientifique sur les gisements de carbonatites à terres rares, en particulier ceux avec un enrichissement en ETR lourds. Le gisement d’ETR d’Ashram est un gisement de type carbonatite enrichi en ETR lourds. Cette étude utilise des observations texturales des minéraux d’ETR pour établir une paragenèse minérale. L’étude rapporte aussi les compositions en éléments majeurs et traces de ces minéraux. Les variations minéralogiques, géochimiques et lithologiques sont évaluées à l’échelle du gisement. Basé sur les résultats …  Read more

It has become increasingly more obvious during the past few years that various hormones have an effect upon renal structure. The fact that thyroxin is capable of producing kidney enlargement has been known for some time. In 1934, during the course of some experiments to determine the effect of androgenic extracts upon the accessory sex organs of castrate rats, it was incidently noted that the weight of the castrate kidney returned to normal after the injection of these extracts. No systematic study of the effect of steroid hormones on the kidney was made, however, until 1939. At that time testosterone …  Read more

Objectives. The main objective of this thesis is to contribute to a better understanding of clinical insight by refining our understanding of its psychological and neuroanatomical determinants in enduring schizophrenia, through the integration of current knowledge on the etiology of insight, and by addressing limitations of previous work in this field. In pursuit of this objective, two studies were performed using data collected from the same sample of enduring schizophrenia patients. The aims of the first study were to 1) examine the relative contribution of different social cognitive abilities and self-reflectiveness to clinical insight, and 2) to identify the strongest …  Read more

Hes1 is a mammalian basic helix-loop-helix (bHLH) transcriptional repressor that inhibits neuronal differentiation and acts together with the corepressor Gro/TLE. Hes1 interacts with Gro/TLE through its WRPW motif and recruits Gro/TLE to specific DNA sites. In contrast, a related Hes family member, Hes6, promotes neuronal differentiation. Little is known about the molecular mechanisms underlying the neurogenic effect of Hes6. To address this question, a structure/function analysis was performed to identify domains of Hes6 important for its biological activity during the differentiation of cortical neurons. It is shown here that the nuclear translocation of Hes6 is required to promote cortical neurogenesis. …  Read more

Depuis la découverte que l'allèle ε4 de l'apolipoprotein E (apoE) est associé avec un risque plus élevé de développer la maladie d'Alzheimer (MA), un nombre grandissant d'études démontre que le cholestérol joue un rôle important dans les mécanismes pathophysiologiques reliés à cette maladie. Plusieurs gènes impliqués dans le métabolisme du cholestérol ont fait l'objet d'études et démontré une associationgénétique avec la MA. PCSK9 est une proprotein convertase qui récemment, fut associée à l'hypercholestérolémie familiale. Cette convertase est un régulateur principal des niveaux de cholestérol plasmatique par sa capacité à promouvoir la dégradation d'un récepteur de surface, le récepteur des lipoprotéines …  Read more

Contexte: La rétinopathie du prématurés (ROP) est une maladie de la rétine affectant les nouveau-nés prématurés, et causant des déficiences visuelles à long terme telles que la cécité. Les traitements actuels pour la ROP sont invasifs et visent à prévenir la progression des dommages rétiniens, mais ne réparent pas ces dommages.Objectif: Étudier l'effet thérapeutique du sildénafil sur la structure rétinienne et la vascularisation dans un modèle de ROP chez le rat.Methodologie: Des rats Sprague-Dawley ont été exposés à l'hyperoxie (80% d'oxygène) interrompue par trois périodes de normoxie de 0,5 heure (21% d'oxygène) par jour ou à l'air ambiant seulement (21% …  Read more

This thesis analyzes the relationship between collaboration and learning to cope with grief in Denise Desautels' poetic works. It shows that this writing strategy influences the representation of mourning and contributes to the learning process, which is characterized by a constant oscillation between opposing poles, such as life and death, the past and present, the self and other, the private and public realms, as well as art and writing. The thesis further demonstrates that Desautels' development of an interdisciplinary approach gives rise to a community of the bereaving and enables the poetic subject to distance herself from melancholy in order …  Read more

La période de l'entre deux guerres est frappée du sceau de la révolution. Tout comme le XIXe siècle confirmait l'établissement du libéralisme, la révolution industrielle, les prétentions démocratiques et le nationalisme intransigeant; la période Versailles-Munich marque l'éclatement des cadres posés au siècle dernier. [...]  Read more

Coordination of complex bimanual movements is essential for the execution of purposeful movements required to manage our daily lives. Because the motor system involves not only the primary motor cortex but also the premotor area, the prefrontal cortex, the parietal cortex, the cerebellum and the basal ganglia, it is no surprise that patients suffering from neurological disorders often present a decline in motor abilities. Due to the lack of a norm-based testing method, few studies have described the normal evolution of gross motor skills across the life span of the normal population, and consequently evaluation in clinical settings remains difficult. …  Read more

NAD-Dependent methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase is a mitochondrial folate-dependent enzyme apparently expressed only in transformed mammalian cells and tissues containing undifferentiated cells. The cloning of both the cDNA and the gene encoding this bifunctional enzyme have led to a better understanding of the regulation of its expression in normal and transformed cells. Southern blot analyses revealed that the gene has a similar organization in normal and transformed cells and no major rearrangement or amplification were detected. The gene encodes two messenger RNAs which differ only by the length of their 3$ sp prime$-untranslated region and are derived by the use of …  Read more

Mutations in the parkin gene are responsible for an early-onset autosomal-recessive form of Parkinson's disease. Parkin is an E3 ubiquitin ligase that acts in the covalent attachment of the small protein ubiquitin to substrate proteins. Although many parkin substrates have been identified, none can fully account for the relatively specific death of the dopaminergic neurons in the substantia nigra that occurs in Parkinson's disease. Using an assay that reconstitutes the ubiquitination reaction completely in vitro, I found that not all disease-associated mutations affected parkin's ligase activity. I used this assay to test a potential parkin substrate identified in our lab, …  Read more

The morphology and properties of polymer blends are closely related to processing conditions. The minor phase dimensions usually range from 0.1 to 10 $ mu$m. A skin/core morphology, with a minor phase undergoing variations in orientation and aspect ratio from the surface to the core of the material is observed in processes such as the injection molding of blends. The use of optical inspection is a potential tool to control the stability and the quality of the product on-line. In this thesis, polymer composites made from different glass fibers and glass microspheres embedded in a matrix of PS are used …  Read more

This study compares how English and French Canadian intellectuals viewed American society from 1891 to 1945. During the period under study, the Dominion experienced accelerated industrialization and urbanization, massive immigration, technological change, and the rise of mass culture. To the nation's intellectuals, many of these changes found their source and their very embodiment in the United States. America, it was argued, was the quintessence of modernity, having embraced, among other things, secularism, democracy, mass culture, and industrial capitalism. In the late nineteenth and early twentieth centuries, Canadian hostility to the United States and continental integration was expressed in two conservative …  Read more

My thesis studies rewriting in the works of Madeleine Ferron. I analyze passages Ferron took from her own writings and rewrote in later texts. Between 1960 and 1995, Ferron produced 114 texts; they include tales, short stories, articles, novels, ethnographic studies and biographies. The author rewrote twenty-two passages and four complete texts. My study describes and analyzes the functions of the rewriting process in these texts: it explores, among others, literary devices, thematic structures and the manner in which the rewritings determine editorial strategies. Rewriting is at the core of the Ferronian esthetic and is here characterized by the transposition …  Read more

Part I. In this work we show that P2X3 currents are acutely modulated by the GPCRs mGluR5 and P2Y2, and by the neurotrophin TrkA receptor, expressed in nociceptors, in the recombinant Xenopus oocyte system. The intracellular C-terminal domain of P2X 3 plays an important role in its functional coupling to TrkA. Preliminary studies suggest a role for PKC in the P2X3-TrkA cross-talk, but other routes may also contribute. Part II. Neurogenic and pharmacological stimulation of vascular smooth muscle P2X1 elicits a contractile response that we found was potentiated by serotonin acting through 5HT2A. We also found in Xenopus oocytes that …  Read more

In this thesis, we introduce SableJIT, a retargetable just-in-time compiler for the SableVM Java virtual machine. Our design attempts to minimize the amount of work required to port (or to retarget) our compiler to a new platform. We accomplish this in three ways. First, we introduce a retargetable backend where the amount of work required to port it is reduced to the implementation of simple well-defined primitive functions. Second, we keep all code related to the internals of the virtual machine in the frontend, making knowledge of the target architecture sufficient for a port. Finally, we provide a good development …  Read more

Historically, development practice and theory has been focused on increasing the productive capacity of the poor towards the modernization of their society. More than often, this approach resulted in excluding the poor from fully participating in their own development. This research project is a qualitative study in the practice of resistance to the domination of expert knowledge and the economic growth model, a resistance focused on developing an authentic solidarity with the poor. Using narratives as a method of inquiry, an attempt was made at defining the commonality upon which our relationship with the poor can be initiated and from …  Read more

To improve the existing methods based on phenotype and/or genotype a new genotyping method was investigated to identify Lactobacillus species. The method used the polymerase chain reaction (PCR) to amplify specific sequences of aminopeptidase (pepN) genes. The primers for the PCR reactions derived from a pepN sequence of Lactobacillus rhamnosus S93. PepN amplification products of 387 bp were obtained from forty three Lactobacillus strains and from some strains of Lactococcus (3), Streptococcus (2) and Bifidobactertium (5). Restriction fragment length polymorphisms (RFLPs) and single-strand conformation polymorphisms (SSCP) methods were used to detect polymorphisms among amplified aminopeptidase DNA fragments from the different …  Read more

L’étude des perceptions et des évaluations morales des enfants liées à l’honnêteté et au mensonge est d’une grande importance, étant donné le lien entre ces processus de pensée sous-jacents et la prise de décision et les comportements moraux ultérieurs chez les enfants (par exemple, Carl & Bussey, 2022 ; Talwar & Lee, 2008b). Alors que la majorité des recherches antérieures ont mis l’accent sur le rôle des facteurs cognitifs (par exemple, la théorie de l’esprit), un petit nombre d’études ont mis en évidence l’effet significatif de deux différents mécanismes importants d’information sociale, les messages verbaux/la prédication et la modélisation sociale, …  Read more

Rodriguez, Rosario (Supervisor1)  Read more

This thesis elaborates three aspects in the field of flow-induced vibrations associated with annular geometries. A method to find the unsteady fluid forces on a cylinder oscillating in annular turbulent flow is developed by considering the superposition of the turbulent fluctuating quantities on potential flow. The theory is compared with experiments. Then, the unsteady fluid forces acting on the vibrating cylinder walls of non-uniform annular configurations are computed by a method which performs the accurate time integration of the Navier-Stokes equations. It is the extension for unsteady flows of the method of artificial compressibility used for steady flows. A time-discretization …  Read more

Preventing the spread of nuclear weapons has been an important objective of the United States since the detonation of the first atomic weapon, but even more so since the end of the Cold War. While Washington has shown some leniency toward allies between the 1950s and 1970s, since then it has engaged in extensive nonproliferation efforts against friends and foes alike. This is because nuclear proliferation has been deemed a security threat for the United States and its allies. However, considering the existential threat, as well as the large shift in the balance of power, nuclear proliferation represents, it has …  Read more

The idea of the control of the sex ratio is not a recent one. According to Gordon (1958), men have been attempting to control or predict the sex of their offspring for thousands of years. This subject was discussed in a Chinese Manuscript about 4,400 years ago. An Egyptian papyrus of 2,200 B.C. noted that a pregnant woman with the use of greenish cast was certain to bear a son. Aristotle believed that the placing of the marriage bed in a north-south direction favored the conception of boys. These are examples of the many beliefs that have been reported regarding …  Read more

Afin de reconnaître la contribution de la biodiversité à la santé humaine, de solides preuves scientifiques additionnelles sont requises. D'autre part, la nature multifactorielle de cette relation nécessite l'élaboration de cadres de recherche innovateurs. Ce mémoire présente une étude de cas multidisciplinaire sur la contribution d'éléments de la biodiversité, en particulier les légumes feuillus cultivés et sauvages, en relation avec la prévention de la cataracte liée à l'âge dans le contexte rural de l'Inde du Sud. Au coeur de ce projet, une étude ethnobotanique a permis d'identifier les facteurs déterminant la consommation de légumes feuillus, et de démontrer l'influence significative …  Read more

Cette recherche vise à évaluer la mécanique d'adhérence d'une nouvelle technique de rénovation utilisant des géosynthétiques en fibre de verre rigide et en polypropylène ductile comme mortier armé de textile (MAT) sur des structures en maçonnerie non armée (MNA) dans l'est du Canada. Dans cette région, de nombreux bâtiments URM vieillissants nécessitent des solutions de réparation et de réhabilitation abordables, une nécessité qui est également stipulée par le Code national du bâtiment du Canada dans le cas de rénovations majeures ou de changements d'utilisation des bâtiments. En raison des importantes fluctuations de température dans la région, les géosynthétiques – connus …  Read more

Methylobacterium extorquens ATCC55366 is an interesting candidate for large-scale production of recombinant proteins. Development and optimization of this recombinant expression system were done using the green fluorescent protein (GFP) gene cloned into expression vectors (pRK310 and pCM110) as model systems. Selection of efficient GFP-expressing clones, long-term production stability without selection in flasks, effects of selection, oxygen and methanol supplies, were studied during fed-batch fermentations in a 20-l bioreactor. Sequential batch-culture cultivations in shake flasks showed that specific GFP production was constant in the presence of tetracycline. However, the GFP production decreased in the absence of this selective pressure. In fed-batch …  Read more

The goal of this study is to identify factors which may be preventing use of an experimental health care program in the People's Republic of Benin. While previous surveys have focused more specifically on the impact of fees on use and demand, our aim to identify a wider range of factors. There are two principle methods by which this can be done. One is to extract possible factors from a review of the relevant literature. The other is to carry out an exploratory, qualitative study in the field. We have used both these methods. A qualitative study is a necessary …  Read more

Lower vertebrates have an active neurogenic stem cell niche located in a peripheral domain of the retina called the ciliary margin zone (CMZ). Müller glial cells and the retinal pigment epithelium (RPE) also behave like latent progenitors. These three cell types can produce neurons throughout life. The production of de novo neurons allows retinal regeneration and growth. Unlike the lower vertebrates, the mammalian retina is unable to restore following injury. However, it also contains some of these latent progenitor sources, such as the Müller glia and the RPE. To which extend these sources of cells produce or could be activated …  Read more

PROBLÉMATIQUE : La plupart des gens à travers le monde, incluant 90% des adolescents canadiens, n’atteignent pas les niveaux d’activité physique recommandés. Une meilleure compréhension de comment, quand, et pourquoi les niveaux d’activité physique des adolescents décline est essentielle. OBJECTIFS : Chez les adolescents, 1) documenter comment les conditions météorologiques influencent la participation à l’activité physique; 2) déterminer si les participants impliqués dans des activités physiques organisées maintiennent des niveaux d’activité physique plus sains; 3) identifier les périodes où la participation à des activités physiques spécifiques décline de façon marquée; et 4) décrire les profils de participation à l’activité physique …  Read more

In this thesis, passive and active 3-branch Ti:LiNbO$ sb3$ waveguide devices were investigated. A multimode field-matching technique was employed to predict the power division in a passive 3-branch waveguide power divider. The limitation and range of validity of this method were pointed out. An alternative method was also employed to predict the power division when coupling between two neighbouring branches is not negligible, as is the case when the branching angle becomes small. The multimode field-matching method was also employed to predict the power division in an active 3-branch waveguide switch, where switching is achieved through the electrooptic effect of …  Read more

Déterminer la fréquence des porteuses d’une mutation du gène BRCA1 et les voies de signalisation moléculaires impliquées dans le cancer de l’ovaire (CO) est important puisqu’il a été proposé que ces patientes pourraient bénéficier de nouvelles chimiothérapies, telles que les inhibiteurs de PARP (Poly (ADP-ribose) polymerase 1). Dans le présent projet, nous rapportons la fréquence des mutations de BRCA1 récurrentes chez les cas de CO de la population Canadienne-Française (CF) qui présente des effets fondateurs. Nous avons également décrit les anomalies génomiques retrouvées chez les porteuses de mutations atteintes de CO. Le dépistage des mutations, utilisant des méthodes basées sur …  Read more

Baum, Shari (Internal/Supervisor)  Read more

The objective of this thesis was to validate the dynamic model SAFE (Soil Acidification in Forested Ecosystems) in a small deciduous watershed of southern Quebec. SAFE could then be used to: (1) identify which processes are governing acidification, and (2) assess the rates of acidification according to various forest conditions. Soil and soil solution chemistry between unburned and burned zones following fire disturbance seventy-five years ago was examined within the watershed. Results showed two major, statistically significant, differences: (1) higher base status, and (2) lower soil solution N in the burned zone. High quality leaf litter of aspen and birch …  Read more

This thesis is concerned with optical self-inscription in solgel derived nanocomposite waveguides. During self-inscription, an electromagnetic wave propagating in a photosensitive medium induces a permanent local increase in refractive index. In turn, this change in refractive index creates a waveguide for the electromagnetic wave that induced it. We discuss similarities and differences between optical self-inscription and the well-known optical spatial solitons which arise in media supporting a transient change in refractive index. In particular, we show that, as for spatial solitons, optical self-inscription can give rise to straight waveguides, waveguides with periodic corrugations and two counterpropagating self-writing beams can undergo …  Read more

In spite of the crucial importance of the Russian front in the outcome of the Second World War, this aspect of the conflict has been studied relatively little in the West since 1945. This omission can be attributed to several factors including linguistic complexity, the difficulty of access to Soviet archives, and the political constraints caused by the ideological climate of the Cold War. Since the time of glasnost' and the collapse of the Soviet block, however, a new era has begun for historians thanks to the release of many documents which had been secret and to the improved ideological …  Read more

Prasher, Shiv (Supervisor2)  Read more

Hristov, D. (Supervisor)  Read more

The discovevy of aldosterone can be considered as a hallmark in the field of mineral metabolism. The elucidation of its role in the maintenance of salt and water balance has resulted into the accumulation of a huge literature mainly concerned with the renal effects of the hormone and with the mechanisms controlling its production. [...]  Read more