McGill University Thèses et mémoires par auteur commençant par N

L'embolisation endovasculaire est une procédure médicale peu invasive utilisée pour occlure un vaisseau sanguin malade. Cependant, les agents emboliques actuels sont limités dans leur utilisation et ont été associés à une mauvaise biocompatibilité et à de faibles propriétés mécaniques. Inspirés par les caillots sanguins autologues—utilisés par les premiers pionniers de l'embolisation—nous présentons les Caillots Sanguins Ingénierée (Engineered Blood Clots, EBC), comme un nouveau matériau embolique temporaire conçu pour tirer parti des avantages inhérents aux caillots autologues, tout en offrant la robustesse et la précision d'une solution ingénierée. Les EBC sont formés à l'aide de la chimie bioorthogonale, qui permet la …  Lire la suite

La maladie de Parkinson (MP) est un trouble neurodégénératif caractérisé par l'accumulation d'alpha-synucléine dans les corps de Lewy et la perte progressive de neurones dopaminergiques. Cette maladie débilitante peut s'étendre sur plusieurs décennies, entraînant des troubles moteurs et cognitifs tels que la bradykinésie, les tremblements, des problèmes d'équilibre et de démence. Bien que plusieurs mutations génétiques aient été associées au développement de la MP, elles ne représentent qu'une minorité des cas. La majorité des cas de MP sont sporadiques, et leurs causes restent largement corrélatives. Les recherches récentes se sont de plus en plus concentrées sur l'axe intestin-cerveau (AIC), qui …  Lire la suite

Natriuretic peptides form a family of structurally-related peptides known to regulate salt and water homeostasis and to cause vasodilation. Synthesis of atrial (ANP), brain (BNP), and C-type (CNP) natriuretic peptides occurs mainly in the heart and brain and has been identified recently in the female reproductive tract. The expression of ANP and CNP, as well as their cognate guanylyl cyclase receptors (NPR-A and NPR-B, respectively), have been detected in the rat ovary. We have shown previously that the expression of the natriuretic peptides and their receptors, in the rat ovary, is modulated by the estrous cycle. Since estrogen and the …  Lire la suite

Laporte, Stephane (Supervisor2)  Lire la suite

Nicolau, Belinda Farias (Supervisor1)  Lire la suite

Cap‘n'Collar (CNC) and Maf families of basic-leucine zipper (bZIP) transcription factors play important roles in mammalian gene regulation, stress response and carcinogenesis. NFE2L3 also named Nrf3 (Nuclear Factor erythroid-derived 2 related factor 3) was the last of the CNC transcription factors to be described in 1999 with yet unknown function. We investigated the regulation of NFE2L3 and found that it is stringently regulated by the proteasome pathway. Furthermore, we detected three different forms of human NFE2L3 in immunoblot analysis. Our data showed that these distinct forms of NFE2L3 can be post-translationally modified and are located in different cellular compartments; the …  Lire la suite

Prolactin is a key mammary gland differentiation factor. However, the contribution of prolactin (PRL) to breast carcinogenesis is less clear. Accumulating evidences indicate that in established breast carcinomas autocrine/paracrine PRL can enhance growth/viability of breast cancer cells. Still, it is not known whether the ascribed pro-oncogenic activity of PRL describes fully the role of PRL in regulating breast carcinogenesis. On the other hand a critical role for Ras-Erk1/2 and TGF-beta (Transforming Growth Factor beta) pathway in breast cancer progression has already been established. Our results indicate that blocking PRL signal leads to activation of Ras-Erk1/2 pathway and TGF-beta pathway, two …  Lire la suite

La division cellulaire est le processus par lequel une cellule se divise en deux cellules filles. Chacune de ces cellules filles doivent hériter d'une copie complète du génome. Sinon, cela mène à la mort cellulaire ou au cancer. Ainsi, il n'est pas surprenant que la vie a fait évoluer des mécanismes pour s'assurer que la division cellulaire est dénuée d'erreurs. Ces mécanismes, appelés « points de contrôle », empêchent la division cellulaire de se produire si des erreurs apparaissent ou si chaque cellule fille n'a pas hérité d'une copie complète du génome. Une molécule exerçant un rôle majeur dans la …  Lire la suite

A user interface to EDS (Electromagnetic Design System) is designed using the X window System and the X Toolkit. The grammar of expressions provided by the user is validated using a bottom-up parser. Equations are converted to postfix/prefix notation, and later displayed in binary tree representation inside pop-up widgets. The interface allows the user to determine equation interdependencies, and to generate flow graphs for different sets of equations within the same application. Equations may be added or deleted from any set of entered equations at any time. Flow graph nodes and links may be queried for equation information. Retrieved information …  Lire la suite

Bone is a dynamic tissue maintained through remodeling whereby it is constantly broken down and repaired through an equilibrium of osteoclast and osteoblast activity. However, when various cancers invade the bone, they disrupt this balance, leading to harmful bone structure and function changes. Radiotherapy, chemotherapy, and surgical resection are the main clinical approaches to bone metastases. Studying cancer cells in vitro relies on 2D monolayer cultures, which in no way represents the physiological tissue microenvironment in vivo. Therefore, preclinical and translational cancer research trends move toward organoid studies and 3D biomimetic models to provide more clinical relevance. Here, we set …  Lire la suite

The mammalian proprotein convertases (PCs) of the secretory pathway are calcium-dependent serine proteinases related to bacterial subtilisin and yeast Kexin. As Kexin and subtilisin, all basic aa-specific convertases contain a comparable N-terminal structure starting with a signal peptide followed by a prosegment and a conserved catalytic domain. The convertases possess additional domains at their C-terminus following the catalytic domain. All PCs exhibit a P-domain prior to the C-terminal architecture, which is specific to each convertase. Three of the basic-aa-specific convertases, furin, PACE4 and PC5 display the presence of a Cysteine-rich domain (CRD). The function of the CRD has not been …  Lire la suite

Since its standardization in the 1960s, the bandwidth of traditional telephony speech has been limited to the 0.3–3.4 kHz narrowband range. Wideband speech reconstruction through artificial bandwidth extension (BWE) attempts to regenerate the highband frequency content above 3.4 kHz in the receiving end, thereby providing backward compatibility with existing networks. BWE schemes have primarily relied on memoryless mapping to capture the correlation between narrowband and highband spectra. In this thesis, we investigate exploiting speech memory—in reference to the long-term information in segments longer than the conventional 10–30ms frames—for the purpose of improving the cross-band correlation central to BWE. With speech …  Lire la suite

Manual wheelchairs (MWC) are critical mobility aids for people with impairments (e.g., stroke, spinal cord injury, multiple sclerosis), promoting independence and participation. Yet users face two major challenge clusters: (1) user-related issues such as inefficient propulsion that cause upper-extremity pain and overuse injuries, and (2) systemic barriers including inaccessible built environments and ableist social attitudes.This thesis adopts the social model of disability and embodied cognition theory, using virtual reality (VR) as a dual-purpose tool to improve both propulsion skills and societal empathy.Key biomechanical factors for low-injury propulsion, semicircular (SC) pattern, appropriate cadence, and large contact angle, are well established, but …  Lire la suite

The advent of next-generation sequencing (NGS) has substantially contributed to our understanding of underlying factors of different cancers. In the first chapter of this thesis, I used NGS (whole-exome sequencing (WES)) to investigate genetic abnormalities associated with metastatic gastric cancer. In the second chapter of this thesis, I used NGS data (targeted sequencing) to investigate association between mutational status of PBRM1 (the second most commonly mutated gene in renal cancer) and clinical variables of affected patients. I have also extended my work to analyze function of PBRM1 in an in vitro model of renal cancer.Chapter-1: Gastric cancer is one of …  Lire la suite

Abstract: Coordination of bilateral hand movements is crucial for daily life. These tasks are classified as ‘bimanual’ or ‘bilateral’ and require precise coordination between both hands. Bimanual movements accomplish a common goal, but bilateral actions like finger tapping do not have a common goal. Stroke alters coordination in bilateral movement, reducing quality of life. Understanding the neural mechanisms of bilateral movement control is crucial to enhancing stroke rehabilitation.Objectives and hypothesis: This study examined the role of the corticospinal tract (CST) in the coordination of bilateral wrist movement. We tested two hypotheses based on motor control theory. Hypothesis 1: In bilateral …  Lire la suite

This thesis focuses on Mean Field Game (MFG) theory with applications to consensus, flocking, leader-follower and major-minor agent systems. The MFG methodology addresses a class of dynamic games with a large number of minor agents in which each agent interacts with the average or so-called mean field effect of other agents via couplings in their individual dynamics and cost functions. A minor agent is an agent which, asymptotically as the population size goes to infinity, has a negligible influence on the overall system while the overall population's effect on it is significant. The thesis is presented in three main parts.The …  Lire la suite

A Phishing attack is a type of identity theft attempting to steal confidential and personal data like Credit Card or banking account information. Different approaches have been proposed to defeat phishing attacks. Most of the approaches rely on a database lookup approach. In this thesis, we present a framework called CASTLE that allows a collaborative approach to build and maintain the databases containing information needed for anti-phishing services. We provide the full design and discuss how phishing sites can be captured using CASTLE. A prototype of this social frame- work for collaborative anti-phishing databases is partially implemented to evaluate the …  Lire la suite

Le cloud computing est idéal pour le stockage d'image et le traitement parce qu'il fournit le stockage énormément évolutif et des ressources de traitement au bas prix. Un des inconvénients majeurs de cloud computing, cependant, est le manque de mécanismes robustes pour les utilisateurs pour contrôler la vie privée des données qu'ils mettent en gérance aux clouds comme des photos. Une façon d'améliorer la vie privée et la sécurité de photos stockées dans des clouds est de crypter les photos avant le stockage d'eux. Cependant, utilisant le chiffrage pour garantir les informations tenues dans les photos écarte appliquer n'importe quelles …  Lire la suite

Potato ranks fourth after wheat, rice and corn as a major food crop. It is an excellent source of nutrients and at the same time relatively inexpensive, therefore it is the mainstay in the diets of people in both developed and developing countries. Potato losses and quality degradation due to the effect of storage variables or processing conditions must be reduced to increase the world food supply. To accomplish these objectives, studies have been conducted to evaluate: (a) quality changes in potatoes during cooking and frying, (b) quality changes in raw potatoes as influenced by storage conditions, (c) changes in …  Lire la suite

L'amortissement thermo-élastique (TED) est un mécanisme fondamental d'amortissement des matériaux où l'énergie est dissipée par la conduction irréversible de chaleur à travers des gradients de température thermo-élastiques présentent dans une structure oscillante. Les premières études de TED ont été réalisées il y a plus de 85 ans. Depuis, l'amortissement thermo-élastique a été intensivement étudié, particulièrement quand il a été démontré en 1990 que le TED peut être un mécanisme d'amortissement majeure dans les systèmes micro-électromécaniques. Cependant, une revue approfondie de la littérature a révélé de nombreux aspects de TED qui restent à être étudié et à comprendre. Dans cette thèse, …  Lire la suite

La gestion de la quantité importante de déchets générés par les activités humaines est un défi majeur actuel. Les activités de traitement de déchets dangereux ont pour but de réduire leurs impacts sur l'environnement et de limiter l'exposition aux substances dangereuses, en contrôlant la quantité de déchets rejetés dans l'environnement sans traitement préalable. Bien que l'objectif de ces activités soit favorable en soit, elles sont la source de problèmes environnementaux involontaires, puisque le traitement de déchets nécessite un apport additionnel en matériaux et énergie, et peut générer la formation de substances intermédiaires nocives. Par exemple, il a été prouvé que …  Lire la suite

Contexte: Le système de soins dentaires au Canada est principalement privatisé. Enconséquence, il a permis une accessibilité limitée aux soins dentaires pour les populations à faible revenu. Ces populations ont le plus grand besoin de soins dentaires dans notre société.Le système de soins dentaires a connu une tendance lente vers les soins centrés sur la personne (PCC) par rapport aux autres disciplines de soins de santé. La plupart des recherches sur PCC ont été réalisées par des chercheurs et des cliniciens qui ont essayé de progresser loin des soins axés sur la maladie. Cependant, les perspectives et les expériences des …  Lire la suite

Kobiela, Marta (Supervisor1)  Lire la suite

Planar and channel optical waveguides fabricated by field-assisted $K sp+$-$Na sp+$ ion exchange in soda-lime glass are studied. An optical characterization of planar surface guides for a given set of fabrication conditions has been performed to determine the refractive index profile. Parallel to this, the ion-exchange diffusion process has been modelled numerically to predict the concentration profile of these waveguides. Direct measurements of the profiles using electron microprobe analysis has been carried out. The results of the characterization were used in the design and fabrication of a novel vertically integrated optical directional coupler. This device, composed of single-mode surface and …  Lire la suite

Planar optical waveguides made by purely thermal and electric field-assisted $K sp{+} - Na sp+$ ion-exchange in soda-lime glass substrates are investigated. Buried waveguides fabricated by a purely thermal backdiffusion process have been demonstrated, for the first time, on soda-lime glass. The diffusion properties, such as the potassium-ion concentration, are determined experimentally using a scanning electron microscope (SEM) and electron probe microanalyzer (EPMA). These properties are then compared to the numerical modeling of the non-linear ion-exchange process and correlated to the waveguide propagation characteristics, such as the refractive index profile. The single-mode dispersion curves are computed by a simple Runga-Kutta …  Lire la suite

The assessment of joint venture appears to be one of the most difficult issues in European competition law. A rational and well-balanced treatment is long awaited. Indeed, the artificial distinction between co-operative and concentrative joint ventures was based on complex and contradictory criteria. The European Commission applied them flexibly at the expense of predictability, damaging the legal certainty that is so necessary for these transactions. The existence of two distinct regimes, one for concentrative and one for co-operative joint ventures, with more favourable treatment for the former, explains why firms wished to subject their transactions to the Merger Regulation rather …  Lire la suite

The objective of this thesis is to investigate the proteins interacting with specific DNA sequences, termed origins of DNA replication in vivo. Two previously described origin binding proteins, OBA/Ku and CBP/14-3-3 were analyzed. Previously, Ku was shown to bind to A3/4, a 36-bp origin sequence, in vitro, and 14-3-3 isoforms were identified as cruciform binding proteins (CBP) which interact with cruciform structures present in mammalian replication origins. Here, the in vivo association of Ku and 14-3-3 with mammalian origins of DNA replication was analyzed by studying its association with the monkey (CV-1) replication origins ors8 and ors12, by formaldehyde cross-linking, …  Lire la suite

In the investigation of the properties of nitrodicyandiamidine, a flashless propellant component, it was found that the substance is a weak acid since a number of stable metal salts could be isolated. Salt formation of nitrodicyandiamidine may be used as a basis for its quantitative estimation. Similar to other urea and guanidine derivatives it couples with aryldiazotates to yield arylazo substituted nitrodicyandiamidine, reacts with hydrazine hydrate to form N (1,1 bishydrazino) methyl N1 nitrourea, and decomposes when formaldehyde is added to its aqueous alkaline solution. Also at elevated temperatures it undergoes rearrangement reactions. The formation of the N (1, 1 …  Lire la suite

Ross, J. H. (Supervisor)  Lire la suite

The stigmatization of people with mental illness is present in all facets of modern society. Many studies have shown that even mental workers trained to work with this vulnerable population held stigmatizing attitudes about mental illness and people with mental illness. This study: (1) examined if the functioning of graduates from mental health agencies was impacted by the attitudes of workers. (2) Compared the attitudes of the mental health professionals of four local agency settings to the US general population. (3) Examined the relationship between worker attitudes and stated agency policies. (4) Examined the relationship between the levels of stigma …  Lire la suite

Foulkes, William (Supervisor2)  Lire la suite

This thesis describes efforts toward iminium ion catalysis of the Claisen rearrangement with a diazepane carboxylate catalyst developed within the Gleason group and illustrates a modular synthetic approach towards chiral hydrazide catalysts.Previously in our group, we have applied a diazepane carboxylate catalyst in iminium ion catalysis of various reactions such as the Cope rearrangement, the Diels-Alder reaction and polyene cyclizations. Inspired by our success in organocatalysis of these reactions, and others, we sought to apply the diazepane carboxylate catalyst to the Claisen rearrangement. The Claisen rearrangement is a [3,3] sigmatropic rearrangement in which a single bond is broken and a …  Lire la suite

[...]The investigation described in the present thesis represents an attempt to develop a satisfactory, simple method of estimating aldehydes in fats and oils. Attention has been largely concentrated on the Schiff reaction, and the objective has been the development of a modification of the Schiff test which will be at once more effective and more adaptable to routine use than existing modifications of the Schiff test.  Lire la suite

L’objectif principal de cette thèse est d’améliorer les stratégies de contrôle prédictif du modèle afin qu’elles puissent étre utilisées pour améliorer davantage l’efficacité et l’optimisation des coûts d’un microréseau. Les systémes de gestion de l’énergie basés sur le contrôle prédictif du modèle actuels peuvent nécessiter beaucoup de calcul et devenir trop lents pour une optimisation en ligne. Une approche améliorée, basée sur le contrôle prédictif du modèle fut développé pour améliorer le temps de calcul et l’évolutivité des schémas de commande actuels basés sur le contrôle prédictif du modèle. À cette fin, les problèmes d’engagement de l’unité et de répartition …  Lire la suite

This thesis aims to explore evidence of Odawa lifeways, or elements of daily life and sustenance practices, in the Waganakising Village during the 1740s from phrases related to agriculture, hunting, and mobility in Father Pierre-Luc Du Jaunay’s (c. 1705-1780) Odawa-French dictionary titled Dictionarium Gallico-ȣtaȣaku[m] (1740). Father Du Jaunay missionized among Odawa in Michilimackinac from around 1735 until 1765, following the community to what the French called the L’Arbre Croche region situated along the Northwest coast of Lake Michigan around 1741. Du Jaunay’s influence remained in the generational memory of the same community from the 1740s until the 1830s. This lasting …  Lire la suite

Rationale: Calcium (Ca2+) activation of the thin filament cannot solely explain force regulation in cardiac muscles, including the rates of force development, force responses to mechanical perturbations, and relaxation. Cooperative activation between myosin cross-bridges induced by the strong-binding between myosin•actin•ADP has been suggested to also contribute to thin filament activation and force development. Little is known about ADP-induced activation in striated muscles. Hypotheses: ADP-induced activation and cooperativity between myosin cross-bridges contributes to cardiac force regulation with Ca2+. Methods: MgADP-induced activation in myofibrils isolated from cardiac muscles were investigated for their force development, force redevelopment following shortening-stretch protocols, and relaxation, and …  Lire la suite

This thesis is a critical examination of the history of philosophies governing public education in the United States. The first half, chapters one through six, outlines American conceptions of the role of the school in relation to the state and to democracy. The second half is an account of critical progressive philosophies that have challenged the American status-quo since the independence. The main argument that I propose here is that the creation of an education system in America has followed the philosophies of federalism and private democracy. These philosophies are economically centered and define the citizen in economic terms. Progressive …  Lire la suite

This thesis presents a new approach to the theory of the labor-managed firm, based on the case of the Yugoslavian labor-managed economy. Instead of income per worker maximization, we suggest that a labor-managed firm in a certain environment and given institutional setting maximizes revenue, while under uncertainty another approach is taken, namely that of social welfare maximization. Inefficient allocation may result in a labor-managed firm whose workers have no transferable property rights. We explore creation of an internal shares market as the means to acquire efficiency. Internal market for shares is also seen as a possible form of transition of …  Lire la suite

Les images de la tomographie par emission de positrons (TEP) ont souventbesoin de segmentation pour l'analyse. En pratique, la segmentation est eectueemanuellement par un expert sur les images, ou des regions d'interet sont delimiteessur les images anatomiques co-enregistres. Cependant, les methodes manuellesdependent de l'operateur et prennent beaucoup de temps, et le recalage entre lesimages anatomique et fonctionnelles du meme sujet peu etre inexact. En outre, lesinformations anatomiques ne sont pas necessairement utiles pour la segmentationde regions fonctionnelles. Pour surmonter ces limitations, nous proposons unsysteme de segmentation automatique base sur un enregistrement TEP-a-TEPoptimise. La segmentation des images est realisee par alignement …  Lire la suite

L’imagerie par résonance magnétique (IRM) est une technique non invasive avec de nombreuses applications en recherche et en clinique. En combinaison avec des données cliniques ou psychologiques, l'IRM structurelle du cerveau humain peut être utilisée pour étudier des questions concernant la nature de la relation entre la structure du cerveau, la santé et le comportement. L'IRM structurelle peut être aussi utilisée pour obtenir des biomarqueurs quantitatifs qui peuvent être combinés avec des algorithmes de classification et utilisés à des fins diagnostiques et pronostiques en clinique. Ces applications nécessitent la segmentation des structures anatomiques. Bien que l'étiquetage manuel par un expert …  Lire la suite

A balanced appreciation of poetry requires both the objective and subjective methods of literary criticism, but it is generally agreed, as W. W. Lawrence writes of the Canterbury Tales, that “the further we recede from our own times, the less can impressionistic analysis stand by itself, no matter how penetrating the imagination behind it.” The main direction of recent Chaucerian scholarship had been to show the inadequacies in purely subjective appreciation. Since in the Middle Ages literature was largely the preserve of the aristocracy and the Church, a knowledge of medieval society and religion is required in understanding poetry dealing …  Lire la suite

The idea of this treatise was conceived and foundations to it were laid last summer during the author's studies in the Department of Finance in Ottawa. At that time the author undertook at the request of the distinguished scholar the late Dr. William Clifford Clark, Depouty Minister of Finance, the preparation of a report on the Canadian Federal Succession Duty. This study convinced the author of the need for detailed legal study of the whole Canadian fiscal law, such an analytical study as would be the legal counterpart to Mr. Perry's descriptive economic work. [...]  Lire la suite

Every human society is a complex organism. Even primitive human society can function only if its operation is ordered in all its basic aspects. This applies in an increased degree to modern civilized societies. We can analyze any society from different viewpoints. From the purely physical viewpoint we will perceive that human and social life can proceed only within the limiting framework of the laws of nature. […]  Lire la suite

In this thesis, we review spectral theory of Laplace-Beltrami operartor on closed manifolds and manifolds with boundary, concentrating on the properties of eigenfunctions in the high energy limit, including asymptotic distribution of eigenfunctions, as well as results about nodal sets. We also discuss results about isospectrality. Finally, we discuss "Quantum Ergodicity" type results for metrics with jump-like discontinuities, including the so-called branching billiards.  Lire la suite

The fast-skeletal-muscle-fiber-specific expression of the troponin I(fast) (TnIfast) gene is driven by an Intronic Regulatory Element (IRE) located within the first intron of the gene. The IRE is a 148 bp transcriptional enhancer that contains several known and suspected cis-regulatory elements. These include the E-box, the closely-spaced MEF2 site and CACT box, the CACC site, and the CAGG element. Previous loss-of-function studies performed using the quail TnIfast IRE suggest that its activity depended on the MEF2 and CACT elements. The goal of my thesis research was to determine whether the MEF2 and CACT sites were not only necessary, but also …  Lire la suite