McGill University Thèses et mémoires par auteur commençant par B

L'intensification de l'agriculture menace les écosystèmes à l'échelle mondiale, entraînant une perte drastique de biodiversité et de services écosystémiques. Les insectes pollinisateurs sauvages qui peuplent les paysages proches des agroécosystèmes de canneberges fournissent d'importants services de pollinisation, mais sont aujourd'hui confrontés à la perte de leur habitat et au déclin de leur population. À l'aide de mesures basées sur les traits fonctionnels, cette étude évalue les services de pollinisation des canneberges fournis par les pollinisateurs sauvages dans un gradient de paysages de la région du Centre-du-Québec. Des pièges Malaise installés dans six types d'habitats différents pendant les saisons de floraison …  Lire la suite

The 45kDa isoform of TC-PTP is a ubiquitous, predominantly nuclear protein. Reports demonstrate that it can exist outside the nucleus; however, immunofluorescence and cellular fractionation techniques point to an almost exclusive residence in the nucleus, and even within the nucleolus. Though the conditions of nucleolar enrichment appear to be serum-dependent, and may involve S52 phosphorylation, the exact circumstances necessary for this localization remain unknown, though TC-PTP C216S mutant, and not an S52A/C216S double mutant had the ability to trap a phosphorylated substrate of ~105kDa, thus encouraging further research into the identity of this phosphoprotein. There is also data implicating TC-PTP …  Lire la suite

A study was undertaken from 1993 to 1994 to determine the effects of intercropping (with Glycine max L Merr., Lupinus sp., Trifolium pratense L.-Lolium multiflorum Lam., or Secale cereale L.) and mechanical weeding (with a rigid tines cultivator, Danish tines cultivator or ridge cultivator) on the population dynamics of insect pests (Diabrotica longicornis Say, Lygus lineolaris Palisot de Beauvois, Ostrinia nubilalis Hubner, and Pseudaletia unipuncta Haworth) on corn (Zea mays L.) in L'Assomption and Sainte-Anne-de-Bellevue, Quebec, Canada. D. longicornis or P. unipuncta populations did not increase. In 1994, intercropping with T. pratense-L. multiflorum (Sainte-Anne-de-Bellevue) or weeding with the Danish tines …  Lire la suite

The thesis is mainly concerned with the initial-value problem for barotropic Rossby waves linearized around a parabolic zonal flow, U (y) = U$ sb0$ + U$ sp prime$ y + U$ sp{ prime prime}$ y$ sp2$/2. It is shown that the non-dimensional equation for the perturbation depends on only one essential parameter, a = $-$2 ($ beta -$ U$ sp{ prime prime}$)/U$ sp{ prime prime}$. The associated Rayleigh-Kuo equation has a continuous spectrum of singulars modes for all values of "a" and an infinite number of discrete Rossby waves for a $< -$.25. In Fourier space the problem has a …  Lire la suite

This study examined the relationships between social physique anxiety (SPA) and physical activity and sedentary behaviours among older adolescents. The research was grounded in self-determination theory (SDT; Deci & Ryan, 1985). Three hundred and eighty one males and females completed scientifically-supported questionnaires. Multivariate and univariate analyses of variance revealed that male adolescents reported lower SPA and higher competence, relatedness, self-determined motivation, and physical activity levels compared to females. Regression analyses supported the integration of SPA in SDT, and the main tenets of SDT were maintained. Specifically, the basic psychological needs were important correlates of motivation, and motivation was a positive …  Lire la suite

This research program involved three studies. Study one was a qualitative study, grounded in constructivist epistemology, in which semi-structured interviews with 11 breast cancer survivors were conducted to better understand women's perceptual, attitudinal/cognitive, affective, and behavioural experiences with their changed physique following treatment for breast cancer. Appearance was important to these women. They had negative perceptions of their changed physique and this evoked primarily negative emotions. These women engaged in appearance management strategies to camouflage the unwanted side effects of cancer treatments and used diet and physical activity to try to alter their physique. Study two involved the completion of …  Lire la suite

Moodie, Erica (Supervisor2)  Lire la suite

Objectifs principaux : Estimer la prévalence du tabagisme chez des patients investigués pour la tuberculose au Cap, Afrique du Sud et vérifier la validité de l'auto déclaration par la mesure de la cotinine sérique. Objectif secondaire : Explorer l'association entre le tabagisme et la tuberculose, de l'infection à la maladie. Méthodes : Il s'agit d'une analyse transversale d'une étude de cohorte dans trois cliniques du Cap, Afrique du Sud. Résultats : Parmi les 424 patients, 56.6% étaient fumeurs et 15.6% étaient d'ex fumeurs. De plus, 28.8% des ex fumeurs ont arrêté moins d'un an avant d'être recrutés. La sensibilité et …  Lire la suite

This is an investigation of the response of a double fixed-ended pultruded fiberglass tube subjected to large lateral displacements, in both quasi-static and dynamic conditions. The experiments yield a two-mode response of the tubing to loading. The first mode, referred to as the local mode, is dominated by crushing of the cross-section. The second mode, referred to as the global mode, consists of beam flexure and shear components. An analytical model, based on deformed geometry, has been developed to predict the response of the tubing under quasi-static loading conditions. Model results compare well with experiments and minimal computation time is …  Lire la suite

Plusieurs experts dans le domaine de la recherche nordique clament qu'un nouveau paradigme émerge, un paradigme caractérisé par une participation communautaire accrue en science. Cette affirmation d'un nouveau paradigme de recherche en science nordique a été exprimée dans de nombreux autres domaines, notamment dans le cadre théorique du mode 2. Comme il n'y avait pas de preuves empiriques d'un changement de paradigme, notre premier objectif était de tester cette affirmation. En utilisant le cadre mode 2, nous avons trouvé que les changements vers les approches de recherche mode 2 au fil du temps ont été modestes et progressifs et que …  Lire la suite

Torsade de pointes (TdP) is a proarrhythmic side effect of antiarrhythmic drugs that prolong the QT interval. The exact electrophysiologic mechanism of TdP is under intense investigation. To study the mechanisms and characteristics of TdP requires an animal model in which the arrhythmia occurs at a high incidence, predictably, reproducibly and resembles the characteristics of the clinical arrhythmia. We have developed such a model in the isolated rabbit heart (chapter II). This model is based on our earlier work showing that in isolated ventricular preparations from the rabbit heart, class III drugs, such as d-sotalol induce a greater increase in …  Lire la suite

Verhaegen, Frans (Internal/Cosupervisor2)  Lire la suite

La glace de mer joue un rôle fondamental dans la régulation du système environnemental arctique et du climat global. Cette couche océanique gelée est un milieu hautement dynamique : sous le forçage des vents et des courants, la glace de mer dérive jusqu'à plusieurs kilomètres par jour. Le mouvement de la glace de mer contribue à la prévisibilité de la banquise, un domaine de recherche actif où des efforts d'observation et de modélisation sont nécessaires pour améliorer nos capacités de prévision en Arctique. L'objectif de cette thèse est d'améliorer les ensembles de données sur le mouvement de la glace de …  Lire la suite

Deux projets de recherche ont été menés afin de déterminer le potentiel du millet perlé fourragé pour la nutrition des vaches laitières. Pour l'étude 1 nous avons évalué les effets de remplacer l'ensilage de maïs (CS; contrôle) par 2 cultivars de millet [c.-à-d., le millet régulier (RM) et le millet sucré (SM)] dans l'alimentation des vaches; alors que pour l'étude 2 nous avons évalué 2 différents stades de maturité du millet sucré [c.-à-d., stade gonflement (EM) ainsi que stade pâteux au stade mature (MM)] en les comparant à l'ensilage de graminée (GS; contrôle). Les paramètres évalués dans les deux études …  Lire la suite

This thesis examines peer education-based harm reduction practices for peoplewho use drugs (PWUD) at music festivals and raves in Montréal/Tiohtià:ke. Given the ongoing drug poisoning crisis and the criminalization of PWUD, exploring the underresearched practice of peer education is vital to the health and well-being of PWUD.Using narrative inquiry, this project draws from my personal experiences as a harmreduction volunteer and interviews with research participants to answer the overarchingresearch question: What do these narratives reveal about peer-led harm reductionpraxis? Participants are recruited from the Groupe de recherche et d'interventionpsychosociale (GRIP). The GRIP offers education and peer support in festival andnightlife …  Lire la suite

Long-acting insulin analogues (glargine, detemir, and degludec) and Neutral Protamine Hagedorn (NPH) insulin are recommended for the treatment of patients with type 2 diabetes whose glycaemia is poorly controlled with other glycose-lowering drugs. Randomized controlled trials reported similar efficacy of long-acting insulin analogues and NPH for glycaemic control, but data on their real-world utilization, effectiveness, and safety are lacking. The overall goal of my thesis was to evaluate the real-world utilization, comparative effectiveness, and hypoglycaemic risk of long-acting insulin analogues and NPH insulin among patients with type 2 diabetes. In the first manuscript, I conducted a population-based study to evaluate …  Lire la suite

I examine the concept of "culture" being promoted in the Canadian policy of multiculturalism and by Tamil refugees safeguarding their culture in Quebec. I take culture in its relation to power as my focus. I explore what culture means to the Tamils, and how the Canadian ideology of multiculturalism is implicated in the way Tamil "culture keepers" (re)construct their cultural identity. This research addresses popular "multiculturalism" movements which use anthropological notions of culture but fail to problematize the notion of culture itself. I illustrate how and why the concept of culture is itself culturally embedded and historically shaped, and thus …  Lire la suite

Free and microencapsulated hepatocytes in an alginate-polylysine-alginate artificial membrane (APA), were implanted intraperitoneally into the Gunn rat, the animal model for Crigler-Najjar syndrome, to reduce serum bilirubin level. Hepatocytes from guinea pigs, Wistar and Sprague-Dawley rats whether free or microencapsulated were equally effective in lowering serum bilirubin levels in the Gunn rat. Buffalo rat hepatocytes however, were immunorejected unless microencapsulated. Decrease in serum bilirubin was concomitant with the appearance of conjugated bilirubin in the bile of Gunn rats as demonstrated by HPLC analysis. Microcapsules containing guinea pig hepatocytes showed less fibrosis than microcapsules containing hepatocytes from different strains of rats …  Lire la suite

McKenzie, Grant (Supervisor1)  Lire la suite

This thesis presents for the first time direct structural measurements of both reversible and irreversible structural relaxation and the glass transition in the metal-metalloid glass Pd$ sb{40}$Ni$ sb{40}$P$ sb{20}$. The techniques have been x-ray diffraction and Mossbauer spectroscopy, and a new analysis method for changes of amorphous diffraction patterns was developed. It is found that irreversible relaxation proceeds by many local shear-type motions involving the metal atoms, and that it is accompanied by a small densification. Reversible relaxation at high annealing temperatures entails the same microscopic processes, but it does not change the density of the glass. The type of …  Lire la suite

Brown, Ernest, 1878-1949 (Supervisor)  Lire la suite

Countries worldwide are becoming increasingly aware of the existing relationship between the economy and the regulatory environment. The pressure exercised by International Organizations, Financial Institutions and Multinational Corporations is spurring this awareness continuously. Lawmakers across the globe are moulding key areas of their legal systems to get an alleged competitive boost on the international economic markets. One of these key areas is secured transactions. According to the studies conducted by prominent economists, by the European Bank for Reconstruction and Development (EBRD), by the United Nations Commission on International Trade Law (UNCITRAL) and by the World Bank (WB), access to credit …  Lire la suite

Pshezhetsky, Alexei (Internal/Supervisor)  Lire la suite

Depuis que l'hypothèse cholinergique sur la dysfonction de la mémoire chez la personne âgée a été proposée par Bartus et collègues en 1982, toutes les études cherchant à mettre en évidence l'implication du NGF chez les sujets normaux âgés et ceux atteints de la Maladie D'Alzheimer (MDA) ont échoué à la fois chez l'homme et chez l'animal. L'hypothèse émise fût que la dégénérescence des Neurones Cholinergiques du Cerveau Antérieur Basal (NCCAB) liée à l'âge pourrait être due soit à une maturation altérée du NGF endogène soit à une réponse réduite au NGF, par un transport déficient, ou bien encore à …  Lire la suite

The area studied in the following notes comprises some 4 square miles, and lies immediately to the southwest of the town of Guysboro proper. The first reference to the geology of the district occurs in Dawsons Acadian Geology (Edinburgh 1855) but details are not described. [...]  Lire la suite

Past studies of the Tuareg have been chiefly concerned with nomadic or semi-nomadic pastoral society. This work is an examination of a sedentary community of former vassals or slaves of the Tuareg who reside at Aouderas, a village of the Saharan Air Massif of northern Niger (West Africa). The economy of Aouderas is multi-sectoral, and is composed of: small-scale irrigated agriculture (which has been analytically separated into subsistence and cash crops); stock-raising of camels, small ruminants, and cattle; and a caravan trade based on the exchange of salt and grain. An analysis of more recent economic developments, namely migration to …  Lire la suite

Our goal is to make progress towards learning auctions from limited access to value distributions. Towards this, we know that VC dimension cannot be used to efficiently obtain the uniform convergence property with respect to the empirical distribution. We show that in fact a more rened tool, the Rademacher Complexity, also requires an exponential number of sample points in the dimension to satisfy uniform convergence. However, given access to approximations of the true value distributions, we show in different settings how to construct auctions that are oblivious to the true distribution, yet yield close to optimal revenue  Lire la suite

Chapter One of this thesis looks at psychoanalytical object relations theory dealing with early childhood, with an aim to outline the shift that has taken place within critical thinking on personal development--from an emphasis on oedipal relations to the auspicious re-exploration of pre-oedipal states. Here the main theme derives from the paradoxical nature of the human skin, whose fluid sensory and communicative qualities profoundly shape our psychological functioning, and thus ultimately our creation of (gendered) knowledge in all its forms. Chapter Two seeks to establish some of the possible socio-political implications of a recovered pre-oedipal sensibility, by way of situating …  Lire la suite

Hydrate-liquid-vapor phase equilibria for systems with binary gas hydrate formers was investigated. The Gibbs phase rule was applied to establish the number of variables needed to specify the systems of interest as well as one additional intensive variable to justify the equilibrium. A novel method was used to map the equilibrium planes for nitrogen+carbon dioxide+water and methane+ethane+water under hydrate-liquid-vapor equilibrium. For the nitrogen+carbon dioxide+water system it was found that along any given isotherm the equilibrium pressure increases with an increased mole fraction of nitrogen in the vapor phase. The methane+ethane+water system forms both structure I and structure II hydrates and …  Lire la suite

The author argues that Nietzsche's discussion of Kant in Twilight of the Idols illuminates a very troubling tension at the heart of political philosophy. By looking at two sections, the author shows the way in which Nietzsche understands Kantian philosophy as an outcome of a historical movement he refers to as the "devaluation of values". Nietzsche's claim is that Kantian critique, rather than establish grounds, ultimately exposes the lack of ground truth and value have in objective reality.  Lire la suite

The purpose of this study is to decipher the means by which the identities of particular people, specifically unaccompanied and separated child asylum-seekers, are socially constructed as risk. Theorized here as "risk identity", this has occurred within a global context increasingly preoccupied with security. Racialized and imbued with ideological notions of citizenship, this preoccupation and the anxieties contained within it, are effectively yet unduly transferred onto individuals, who for a variety of reasons not innately related to security, are seen as undesirable. The "risk identity" classification becomes the means by Which their exclusion is legitimized and perpetuated. The increased movement …  Lire la suite

Anatomically the lung consists of two conducting systems to bring the inspired air and venous blood into contact. The effectiveness of gas exchange is largely dependent on the efficiency of these distribution systems. If parts of the lung are ventilated but not perfused, or perfused but not ventilated, no gas exchange will occur in these areas. Furthermore, ventilation in excess of perfusion, or perfusion in excess of ventilation are relatively inefficient. The optimum distribution is clearly when the quantities of ventilation and perfusion are matched, that is, the Ventilation/Perfusion ratio is equal in all lung units. To predict gas exchange …  Lire la suite

Les maladies glomérulaires sont caractérisées par une perturbation de la perméabilité glomérulaire, souvent due à des lésions aux cellules épithéliales glomérulaires (GEC) ou des podocytes, qui sont des cellules hautement différenciées de la paroi capillaire glomérulaire. Les mécanismes sous-jacents aux lésions des podocytes convergent vers une perturbation du cytosquelette. La kinase de type Ste20 SLK est une protéine kinase de type sérine/thréonine qui régule la migration cellulaire et la structure du cytosquelette. Bien qu’une délétion complète de SLK soit létale pendant l'embryogenèse chez la souris, les souris avec une délétion de SLK étant spécifique aux podocytes présentent un dysfonctionnement accru …  Lire la suite

A glance at a large scale map of Labrador-Ungava brings to the forefront the fact that a myriad of lakes abound in the area. Schefferville, Quebec, the site of the McGill Sub-Arctic Research Laboratory and of the field work included in this thesis, is in an extremely advantageous location for the study of lakes, both large and small, for besides being in a formerly glaciated area, it is located on folded sedimentaries surrounded by the Canadian Shield. [...]  Lire la suite

The scope of the indium-mediated allylations in aqueous media has been successfully expanded and an improved understanding of the synthetic utility of the reaction has been developed. The range of useful functionalities that can be efficiently produced by the methodology has been increased and the concise construction of naturally occurring and/or biologically significant substrates has been undertaken. We have demonstrated how N-acylimidazoles could be allylated under controlled temperature conditions, in aqueous media furnishing predominantly 4-alkyl-1,6-heptadien-4-ols. The intermediate alpha-alkyl-beta,gamma-unsaturated ketones were present in significant amounts only when the bulk of the acyl or alpha substituents were such that it interfered with …  Lire la suite

The balsam woolly aphid, Adelges piceae (Ratz.), is an introduced pest of European origin. It was discovered in Maine and New Hampshire in 1908, in Nova Scotia in 1929, and in Newfoundland in 1949 (Balch, 1952). True firs, Abies spp., are the only hosts of the aphid which causes severe damage to balsam fir, A. balsamea (L.) Mill., the predominant fir species in the Atlantic Provinces. Severe damage is caused by high numbers of aphids feeding in the crowns and on the stems of trees. In Newfoundland, rapid deterioration of tree crowns predominates; stem attack occurs infrequently and in widely …  Lire la suite

Strong, Teresa (Supervisor1)  Lire la suite

Purpose. The purpose of this study was to examine the relationships between women's perceptions of their childbirth experiences and their early postpartum parenting behaviours and to determine the factors that predict the birth experience. Methods. Of all women giving birth on Prince Edward Island between October 27, 2004 and December 31, 2005, 652 women and their newborns were recruited from the postpartum units of two general hospitals. Initial data were collected at 12 to 48 hours postpartum using three self-report questionnaires and chart review. Women's childbirth perceptions were then scored, and a sub-sample of these mother-infant pairs (n=175) was assigned …  Lire la suite