McGill University Thèses et mémoires par auteur commençant par N

Les protéines sont des macromolécules riches en groupements fonctionnels. L'utilisation de protéines comme matière première pour la synthèse de matériaux a été sous-évalué dans une large mesure. Beaucoup de sous-produits riches en protéines proviennent de l'industrie de l'élevage, de l'agriculture et de la production alimentaire. Toutefois, ces sous-produits sont traditionnellement utilisés dans la formulation de nourriture pour animaux. Les chercheurs ont exploré l'utilisation de protéines comme monomères pour la production de matériaux fonctionnels. Parmi les matériaux polymères, les hydrogels à base de protéines sont attrayants en raison de leur biocompatibilité, biodégradabilité et de leur sensibilité aux stimulations environnementales. Par conséquent, …  Lire la suite

Les nanomatériaux en or ont beaucoup d’applications dans les domaines allant de la thérapie photothermique à la catalyse. Cependant, l'accès à de telles applications nécessite souvent des modifications en surface des nanomatériaux où des stratégies de liaison à d'autres matériaux. Dans ce contexte, cette Thèse rend compte du développement des modifications et des applications des nanotiges d'or (AuNRs) et des nanoparticules d'or (AuNPs).La réaction de Diels-Alder à demande inverse (IEDDA en anglais) a été adaptée pour lier de manière covalente des AuNRs à des nanotubes de carbone monofeuillets (SWCNTs en anglais). Cette méthode de préparation thermiquement douce permet l'introduction potentielle …  Lire la suite

Les hydrogels adhésifs résistants trouvent une utilisation croissante dans l'ingénierie et la médecine en raison de la ténacité élevée de la matrice et de la forte adhérence à divers substrats. Dans de nombreuses applications, les hydrogels adhésifs résistants sont exposés à diverses conditions environnementales et de charge. Un exemple est le chargement cyclique prolongé lorsque les hydrogels sont utilisés comme adhésifs tissulaires s'interfaçant avec des tissus à déformation répétée tels que le cœur et les poumons. Un autre exemple est le gonflement lorsque des hydrogels implantés entrent en contact avec des fluides corporels, ce qui détériore les performances mécaniques. Bien …  Lire la suite

Acid sphingomyelinase (ASM), a member of the saposin like protein (SAPLIP) family, is a lysosomal hydrolase that converts sphingomyelin to ceramide. The deficient activity of ASM causes a variant form (i.e., type A/B) of the inherited disorder Niemann-Pick disease. The lysosomal targeting mechanism of ASM has not been conclusively identified. Previous studies suggested that ASM could use another membrane-associated receptor as well as M6P receptor to target lysosomes. Sortilin, a type I transmembrane glycoprotein, belongs to a novel family of receptor proteins. Both the luminal domain and the cytoplasmic domain of sortilin show structural features typical of receptors involved in …  Lire la suite

The fundamentals of chlorine dioxide bleaching of softwood kraft pulp are studied by measuring the development of the inorganic chlorine species: chloride, hypochlorous acid, chlorite, chlorine dioxide and chlorate, as well as organically bound chlorine in the pulp and bleach solution. The pulp delignification is characterized by determining the development of the concentration of methanol and methoxyl group containing material in the bleach liquor and that of the functional groups in the residual lignin. A complete chlorine mass balance was obtained throughout the bleaching reaction. Based on the development of the chlorine containing species, a series of reactions are formulated …  Lire la suite

Six experiments tested the assumption that, in visual perception, observers have reliable and direct access to the equivalence of shapes in projective geometry (I call this "the invariance hypothesis in the theory of shape constancy"). This assumption has been made in the study of vision since Helmholtz's time. Two experiments tested recognition of the projective equivalence of planar shapes. In another four experiments, subjects estimated the apparent shape of a solid object from different perspectives. Departure from projective equivalence was assessed in each study by measuring the cross ratio for the plane. This measure of projective invariance is new to …  Lire la suite

Isac, Mihaiela (Supervisor2)  Lire la suite

Spalanzani (1768) was the first to study regeneration in vertebrates. He discovered this phenomenon in the limbs and tails of newts and frog tadpoles. Since then and particularly during the last seventy odd years, regeneration in vertebrates has been an attractive field of research. The studies have been directed both towards discovering the presence, absence or extent of regenerative capacities in different animals as well as towards reaching an understanding of the actual processes involved.  Lire la suite

Building practices in rural areas have developed in response to a variety of interrelated factors like climate, local physiography and socio-cultural traditions. The rural house is as much an agrarian product as the crops and livestock depending on a balanced eco-system. It is characterised by a dependence on the immediate natural environment for materials, high labour and low energy inputs in construction. Unfortunately, depletion of natural resources, changes in resource management structures and rapid monetisation of the rural economy have had abrupt and often detrimental effects on the condition of rural shelter. This research attempts to understand the characteristics of …  Lire la suite

We investigate a particular type of geometry, namely median metric spaces. This encompasses median graphs, as well as simple combinatorial structures known as spaces with walls. The group-theoretic applications are towards the Kazhdan property and the Haagerup property.  Lire la suite

The identification of nicotinic acid as the pellagra-preventative factor has necessitated the development of accurate methods for its estimation. Most chemical methods are colorimetric procedures based upon the Konig reaction (52) in which the pyridine ring is ruptured with cyanogen bromide. The slight color produced is intensified by the addition of an aromatic amine. This reaction is not specific for nicotinic acid but is given by any alpha-unsubstituted pyridine compound (34). The natural-occuring nicotinamide and related compounds which are biologically active must be converted to the free acid by hydrolysis with acid or alkali prior to the application of the …  Lire la suite

The hippocampus is an instrumental brain region for a number of important functions, including spatial information processing, learning, and memory. To fully understand the mechanisms underlying these functions, it is critical to understand the interaction between hippocampal inputs and local interneurons. One input of particular interest is direct input from the entorhinal cortex (EC), which contributes to the generation of hippocampal theta rhythm and which transfers vital sensory information to the hippocampus. An interneuron population likely to play a role in modulating this input is the oriens lacunosum-moleculare (OLM) interneuron. A number of characteristics, including the position of their axon …  Lire la suite

Hemmeon, J. (Supervisors)  Lire la suite

Acute promyelocytic leukemia (APL) has become a highly curable disease with contemporary treatment, with all-trans retinoic acid (RA) serving as the cornerstone of therapy. Interactions between the retinoic acid receptor alpha (RARA) and co-regulators play a key role in coordinating gene transcription and myeloid differentiation. In the majority of APL cases, RARA is fused with the promyelocytic leukemia (PML) gene, resulting in the expression of the fusion protein, PML/RARA. Here, we report that Nucleophosmin (NPM) associates with, and negatively modulates, PML/RARA transcriptional activity. Furthermore, increased levels and association of NPM underlies resistance to retinoic acid (RA) in a model APL …  Lire la suite

This thesis studies the intellectual development of the painter and writer Wyndham Lewis (1882-1957). His career is seen as an unique expression of the creative and critical intelligence within modern society. The liberal, secular, and individualistic aspects of Lewis's thought are stressed. The thesis concentrates on four aspects of Lewis's life and work. First, Lewis's relationship with T. E. Hulme, usually described as one of direct influence, is shown to be adversarial and complicated by basic differences of their worldview. Second, the nature of Lewis's fascism is discussed using a new reading of Hitler (1931). Third, Lewis's view of the …  Lire la suite

The general view of pragmatism holds that universal moral norms cannot be justified within a pragmatic perspective. Pragmatism, thus, is associated with relativism. C.I. Lewis says that pragmatism without universal norms is a self-contradiction. I defend the view that there are two dimensions to pragmatism. I claim that Lewis' philosophy encompasses both. I argue that there are two different pragmatic justifications implicit in his philosophy; while one is associated with relativism, the other is not. I call them: "the pragmatic choice of the best" and "the pragmatic justification of the non-repudiable," respectively. What is justified by the first is a …  Lire la suite

Cette thèse explore les pratiques et les représentations du système de justice pénale écossais dans la période 1678-1688. À l'aide de nombreuses études de cas, cette thèse examine les motivations politiques et les principes juridiques derrière les politiques du gouvernement écossais, et comment les gens naviguaient ce système. Le récit historique traditionnel portant sur la Restauration écossaise (1660-1688), très souvent influencé par les événements contemporains en Angleterre, est habituellement celui d'un royaume despotique en raison de ses politiques sévères et souvent persécutrices envers les dissidents religieux. En réalité, le gouvernement écossais de la Restauration était conscient de sa mauvaise réputation …  Lire la suite

The experimental work embodied in the following thesis has been carried out during the last four years and has been published from time to time in varions journals, as each phasewas brought to completion. These experiments were designed to investigate the reaction of the gastro-intestinal tract to temperature variations, to the action of drugs, such as adrenaline, pilocarpine, acetylcholine, atropine and ergotoxine, and, finally, to sympathetic and parasympathetic nerve stimulation. For the last an anatomical, histological and physiological study of the vascular supply of the gastro-intestinal tract was necessary, because, as will be shown, the sympathetic nerves are distributed to …  Lire la suite

With a view to securing an unknown highly substituted cyclopropane ketoester, E. E. Massey in this laboratory carried out a series of reactions based on the work of previous investigators, and obtained a substance having the correct analysis and showing some of the expected properties. In certain respects, however, abnormalities were observed, and from the evidence marshalled in this thesis it must be ooncluded that the substance is actually α,β-diphenyl-γ-benzoylbutyrolactone.  Lire la suite

The qualitative identification of organic halogen compounds has always been a matter of difficulty. For many years the only method was dependent upon the physical constantsof the compound, such as melting and boiling point, refractive index, and density, in combination with a quantitative estimation of the halogen. [...]  Lire la suite

My dissertation is concerned with two central issues: analysis of theory-practice gaps in aesthetic theories applied to avant-garde musics, and problems of visibility and respect in theorizing across cultures. In the first chapter, I examine a case study, John Coltrane's successive improvisations on "My Favorite Things," under two different theories in order to show how theories shape our view of the practices we are trying to explain. In the second chapter, I take up Coltrane's practices and their relations to theories once again but, in a reversal of the previous chapter's focus, I show how examining theories through practices can …  Lire la suite

Gomori 's silver methenamine stain was adapted for use in the electron microscope and applied to the mouse duodenum to investigate the endocrine cells claimed by other researchers to be argentaffin and argyrophile. After paraformaldehyde fixation it was observed that both biconcave and spherical granule endocrine cell types were argentaffin. By employing densitometry on the granules within these cell types and also by determining their percentages of spherical granules, it was discovered that the distinction between the cell types was poorly defined. It was concluded that the duodenum possessed one family of argentaffin cells with variation in number, shape and …  Lire la suite

The laws which govern the flow of fluids in regular conduits have been extensively studied and definite patterns of behaviour have been resolved. However, there is still much work to be carried out before the principles underlying the flow of fluids through irregular channels--such as those formed between the particles in a packed bed--are thoroughly understood. The problem is admittedly difficult, not so much because of the large number of variables involved, but rather because of the complex nature of some of the latter. [...]  Lire la suite

In 1933 F. A. Gibbs, by his description of a thermoelectric blood flow recorder of small bulk and simple construction, enormously expanded the application of the well known physical principle of the thermocouple to physiological research. Since its introduction, and that of the somewhat similar invention of Schmidt, the instrument has been of especial·value in problems relating to the cerebral circulation. Much of the work, such as that of Lennox and Gibbs (1933, 1934, 1935), is based on qualitative estimations of variations in the total blood flow through the brain. The thermocouiple has been put to a yet more interesting …  Lire la suite

La traçabilité est un outil utile pour raisonner à propos de nombreux aspects d’un logiciel grace aux connections entre les artéfacts qui constituent ce logiciel. Par exemple, les parties prenantes peuvent utiliser la traçabilité pour évaluer la qualité d’un logiciel selon de nombreuses dimensions, comme la conformité réglementaire. Le contenu sémantique de ces liens ou, ce qu’ils communiquent à une partie prenante reste cependant notablement inexploré. De plus, les systèmes de suivi des problèmes fournissent une grande quantité de données sur les événements de traçabilité et leur contexte, en particulier dans le cas des projets logiciels en source libre ou …  Lire la suite

This thesis is an investigation of St. Petri Church via relevant drawings and photographs by Sigurd Lewerentz. It explores his design through the Lutheran liturgy and theology revealing possibilities of an architecture based on spiritual harmony and bodily experience. It is an attempt to view Lewerentz's architecture outside limitations of style---demonstrating his spiritual belief in a harmony between both visible and invisible elements of architecture, as well as the act of making architecture through the relationship between drawing and building. Seen in such a context Lewerentz's work at St. Petri points to valuable strategies for the practice of architecture today.  Lire la suite

According to the structuralist Claude Levi-Strauss, all myth has but one same structure. The purpose of this study is to expose the mythico-initiatory edifice that informs Vendredi ou les limbes du Pacifique, Le Roi des Aulnes, as well as Les Meteores, Michel Tournier's "trilogy". To write, according to Tournier, cannot be a matter of literary creation, but simply of literary renewal. Vendredi ou les limbes du Pacifique, Le Roi des Aulnes and Les Meteores represent literary reflections on the primordial importance of Myth, for the Artist and above all, for Man; it is this mythic dimension that makes Tournier's entire …  Lire la suite

Carcinoembryonic antigen (CEA) is a cell surface protein attached to the membrane by a glycophosphatidylinositol (GPI) anchor, a common modification of cell surface proteins. CEA is overexpressed in many human cancers, and plays a role in tumor progression through its ability to activate certain integrins, thereby blocking cellular differentiation, inhibiting anoikis, and disrupting normal tissue architecture. Previous work established that the CEA GPI anchor contains important and specific information directing these functions, which served as the basis for an investigation of the underlying mechanisms involved. The ability of the GPI anchor to determine protein function was examined using a chimera …  Lire la suite

This thesis presents a deep learning framework, along with key insights and design decisions, for the problem of Multiple Sclerosis (MS) lesion segmentation and detection. Our approach, inspired by nnU-Net ('No-New-Net'), confirms that a baseline UNet, properly configured and optimized, can achieve state-of-the-art performance on medical image segmentation tasks. Our approach shows significant performance gains over previously published results on the same dataset. Next, we examine the segmentation-detection tradeoff that exists when segmenting MS lesions of different sizes. Specifically, in cases where there is a mix of small and large lesions, standard binary cross entropy loss will result in better …  Lire la suite

Cette thèse comprend une partition pour un ensemble à vent symphonique et une soprano, whole beauty now lies in memory (2012) ainsi qu'une analyse de cette ouvre. L'introduction de ce texte détaille les méthodes de la réorganisation et de l'emprunt musicaux, à partir desquelles cette œuvre a été composée. Les chapitres suivants discutent successivement des aspects de la tonalité, du rythme, de la forme et de l'orchestration. Chaque chapitre s'attache à montrer comment le concept de réorganisation est appliqué suivant l'aspect respectivement étudié et développe ainsi la méthodologie du compositeur.  Lire la suite

This thesis focuses upon Clyde River Inuit knowledge, concerns, and attitudes to community tourism development and protected area establishment. The findings suggest that a cross-section of residents have a positive attitude toward community tourism development because it may provide local economic benefits. Residents also support the Igalirtuuq Conservation Proposal because it protects the endangered bowhead whale and its critical habitat, while at the same time stimulating tourism development. Clyde Inuit are reluctant to attribute social and environmental costs to these initiatives but are, nevertheless, able to point out some specific negative impacts that such projects might have on their village. …  Lire la suite

One of the more recent and alluring phrases used by development and resource management practitioners and theorists is "traditional ecological knowledge." Although there is a substantial amount of the literature on this subject, these studies have unfortunately an inadequate characterization of the way in which indigenous people view, order, internalize, and manipulate environmental information. This deficiency indicates a need to (a) improve our understanding and use of indigenous knowledge as an instrument for sustainable development and resource management and (b) revise some of our present conceptual, theoretical, and methodological understandings. This dissertation examines these issues by investigating the ecological knowledge …  Lire la suite

La présente thèse doctorale explore les marqueurs électro-physiologiques des mécanismes sous-jacents du traitement de la phrase. Les deux études qui la constituent établissent les bases d'une réévaluation d'un des modèles les plus influents à l'heure actuelle (Friederici, 2002). Un point central de ce dernier est connu sous le nom de « Blocage sémantique ». Cette hypothèse prédit qu'une erreur de catégorie syntaxique, mettant en échec la formation syntagmatique, « bloque » l'analyse sémantique du mot qui comporte cette erreur. Friederici, Steinhauer et Frisch (1999) semblent appuyer cette hypothèse. Ils rapportent en effet que la composante N400 (index de traitement sémantique) …  Lire la suite

Insulin-like growth factors have well characterized mitogenic and antiapoptotic effects in a number of normal and transformed cell types that are mediated through binding to the IGF-I receptor. IGF activity is modulated by at least six insulin-like growth factor binding proteins (IGFBPs) that bind IGFs with high affinity. Recently, it has been proposed that IGFBPs may play an important role in regulating apoptosis. This thesis provides evidence that IGFBPs induce apoptosis in vitro, and are associated with involution of ventral prostate and with regression of androgen-dependent and estrogen-dependent tumors in vivo. We show here that IGFBP-3 induces apoptosis in MCF7 …  Lire la suite

Nemes, J. (Supervisor)  Lire la suite

Brierley, John E. C. (Supervisor)  Lire la suite

Fourier transform infrared (FTIR) spectroscopy was employed to monitor the oxidation of edible oils in the absence and presence of antioxidants. Three synthetic antioxidants (butylated hydroxyanisole, propyl gallate and tert-butylhydroxyquinone) were added to menhaden oil at three different concentrations (1%, 0.1%, and 0.01%), and the FTIR spectra of the oils under conditions of oxidative stress were recorded as a function of time. The efficacy of each antioxidant was assessed by monitoring bands at 3444 cm$ sp{-1}$, characteristic of hydroperoxide formation, 971 cm$ sp{-1}$ for trans double bond formation, and 3008 cm$ sp{-1}$ for cis depletion. An FTIR spectroscopic method was …  Lire la suite

Whey protein isolates (WPI) have been indicated to have potent cholesterol lowering and antioxidative properties. Such effects, however, are not consistently observed, which could be the result of major differences in the processing, isolation and composition of WPI. Moreover, the mechanisms of action or the bioactive component(s) in WPI are poorly understood although the relatively high cysteine content in WPI has been suggested to play an important role. Although high dietary cysteine has been shown to lower plasma homocysteine concentrations, the impact of WPI in this regard has not been investigated. The overall objective of this thesis was to examine …  Lire la suite

Bergevin, Yves (Supervisor1)  Lire la suite

It has often been suggested that bilingual children might have enhanced metalinguistic awareness, as compared to monolingual children. In this paper, the evidence for such a stance was reviewed. In contrast to most previous thinking, it is suggested here that if metalinguistic awareness were enhanced at all by exposure to a second language, it might be the process of learning a second language that draws children's attention to their knowledge about language. Accordingly, a group of preliterate second-language learners was compared with monolinguals and bilinguals on word and phonological awareness tasks. It was found that, for the most part, there …  Lire la suite