McGill University Thèses et mémoires par auteur commençant par Y

E-commerce is a new way of doing business. It is becoming increasingly important to everybody. The objective of this thesis is to compare various design approaches and to find out the best solution for small businesses. Some commonly used technologies in developing e-commerce systems are introduced in the first three chapters. The topics covered are from Web standards and protocols to Web planning and design, from Web servers to server side programming, and most importantly, Java technology and IBM's WebSphere. Based on these technologies, two solutions are presented: building from scratch with Java servlets and building with IBM's WebSphere. We …  Lire la suite

Colletotrichum coccodes is being developed as a bioherbicide to control velvetleaf. An effective and economic process for mass production of C. coccodes sports is required for its possible development as a bioherbicide. A modified Richard's solution containing V-8 juice has been used to produce C. coccodes spores in shake flasks. However, V-8 juice is not available as a bulk commodity and is too expensive for commercial production of a bioherbicide. Soy protein and casamino acids were equal to and can replace V-8 juice for sporulation of C. coccodes . Using the Plackett-Burman experimental design, the effect of the various components …  Lire la suite

Problems of Rock Mechanics related to mines are usually concerned with stress distributions and the properties of the rock mass surrounding mine excavations. Neither aspect at present can be reduced to absolute values. Stress distribution in mines is being studied mathematically, photoelastically through various types of models, and also by measurements in situ. [...]  Lire la suite

Interleukin-8 is a chemokine which is chemotactic for neutrophils and T-lymphocytes and plays a crucial role in the pathogenesis of inflammatory bowel disease. Intestinal mucosal epithelial cells produce IL-8 in response to pathogens which mediates bidirectional communication between pathogen and host. The objective of this study was to investigate the molecular mechanisms involved in IL-8 gene regulation in T84 human colonic epithelial cells. To determine if IL-8 plays a role in the pathogenesis of intestinal amebiasis, the effect of Entamoeba histolytica on IL-8 gene expression was investigated. E. histolytica secreted components enhanced IL-8 mRNA expression and protein production in the …  Lire la suite

This thesis examines the reconfiguration of life trajectories of Chinese women in the face of challenges as a sandwich generation through two unconventional pathways: remaining single or immigrating to Canada. The sandwich generation refers to individuals bearing simultaneous responsibilities for their aging parents and young children. Under the evolving family planning policies in China, a “sandwiched couple” may find themselves as the sole caregiver for four elders plus one or more children. This informal care work, on top of formal employment work, poses significant risks to the physical and mental well-being of the sandwich generation. In response to the challenges …  Lire la suite

Levine, Martin D.  Lire la suite

The kinetics of the functionalization of linear and cross-linked poly(methyl acrylate) (PMA) and its low-molecular-weight analogs by reactions with various amines in a series of binary solvents or in the solid state have been studied in situ by $ sp{13}$C NMR. Fitting the kinetic data of reactions of PMA with ethanolamine and n-hexylamine (HAN) in DMSO-rich solvent by use of the neighboring-group model shows an auto-acceleration effect due to hydrogen-bonding and/or polar interactions, and hydrophobic interactions; however, PMA and cyclohexane-methylamine shows an auto-retardation effect due to strong steric hindrance. At low extent of reaction the steric effect dominates the kinetics …  Lire la suite

Retrotransposition is an active process in mammalian gene evolution. It involves the reverse transcription of an mRNA transcript and the subsequent re-integration of the resulting cDNA into genomic DNA. This study was to derive a complete picture of the role of gene retrotransposition in the genome evolution of vertebrates, particularly in mammals. A robust procedure to annotate putative retrogenes (PRs) was applied to eight vertebrate genomes (human, chimp, dog, cow, rat, mouse, chicken and the puffer-fish T. nigriviridis). Mammalian genomes were estimated to contain 400-800 PRs (up to ~4% of genes). For the eight genomes studied here, no significant correlation …  Lire la suite

The sequencing of eukaryotic model organisms has provided us an unprecedented opportunity for a genome-wide characterization of Transposable Elements (TEs) and the study of TE-host relationships. By developing methodologies on database mining, we explored the existence of MUtator (Mu)-Like Elements (MULEs) in Arabidopsis thaliana and Oryza sativa. Mu elements were first discovered in Zea mays; so far, a dozen of the elements have been identified in the genome. We identified a total of 1392 MULEs from the sequenced Arabidopsis genome. They represent one of the most abundant, diversified, yet still mobile DNA transposon families in eukaryotes. The Arabidopsis MULEs are …  Lire la suite

In order to determine the role of biogenic monoamines in the control of pancreatic secretion, the metabolism and disposition of 5-hydroxytryptamine (5-HT) and dopamine in rat exocrine pancreas was studied. Pancreatic acinar cells contained 5-HT which was located exclusively in the zymogen granule fraction. Aromatic amino acid decarboxylase activity was located exclusively in the cytosol of acinar cells and was substrate specific for the L-isomers of hydroxylated aromatic amino acids 3,4-dihydroxyphenylalanine(L-DOPA) and 5-hydroxytryptophan (L-5-HTP). Each substrate competitively inhibited the decarboxylation of the other. When incubated with {('14)C}5-HT dispersed acinar cells took up the amine and concentrated it in zymogen granules. …  Lire la suite

Objective. To examine the temporal change in fetal death risk in the U.S. from 1991 to 1997 and to assess the extent to which changes in registration practices and labor induction have contributed to that change. Setting. United States. Design. Cohort study. Participants. All singleton pregnancies 20--43 weeks of gestation in 1991 and 1997. Main outcome measure. Fetal death risk (fetal deaths per 10,000 fetuses at risk at each completed gestational week). Results. From 1991 to 1997, the overall fetal death rate fell from 77.7 to 67.8 per 10,000 total births. However, fetal deaths at 20--22 weeks as a proportion …  Lire la suite

Newly synthesized soluble lysosomal proteins are transported from the Golgi apparatus to the lysosomes by two mannose 6-phosphate receptors. However, the sphingolipid activator protein prosaposin is targeted by the alternative trafficking receptor, sortilin. Prosaposin is the precursor of four lysosomal saposins required for the hydrolysis of sphingolipids. A previous study demonstrated that the removal of its C-terminus abolished the trafficking of prosaposin to the lysosomes. To identify the sequences and amino acids involved in the interaction of prosaposin to sortilin and its transport to the lysosomes, we generated six prosaposin deletion constructs and examined the effect of truncation by co-immunoprecipitation …  Lire la suite

Preservice teachers (PSTs) often complete their undergraduate programs feeling unprepared or reverting to traditional methods for teaching science in elementary classrooms. In Québec, although English-language teacher preparation emphasizes practice-based pedagogies and elementary PSTs learn about inquiry-based methods in their science methods courses, they may have few opportunities to practice teaching science during their field placements. Yet, limited research examines PSTs’ perceptions of integrating inquiry-based science teaching methods into their field placements. This qualitative case study addresses the following research questions: RQ1) What are elementary PSTs’ perceptions of effective inquiry-based science teaching? RQ2) What are elementary PSTs’ expectations for teaching science …  Lire la suite

Straw, William O. (Supervisor1)  Lire la suite

A polaron forms when a charge carrier distorts its surrounding atoms and becomes self-trapped by the potential energy well produced by the distorted lattice. Polaron formation severely limits the conduction properties of a range of materials, which inhibits the development of various technologies including batteries, oxide electronics, photocatalysis, and sensors. Therefore, to optimize the performance of such devices, it is essential to understand the mechanisms of polaron formation from a fundamental point of view. In this thesis, a comprehensive study of the initial stage of polaron formation is presented. The initial stage here refers to the transition from a delocalized …  Lire la suite

In vitro studies will contribute significantly to an understanding of cell growth and differentiation in the adult pancreas. This thesis reports on the changes occurring when acinar cells, terminal ducts and islets are grown in culture. A number of methods for adult pancreatic duct epithelial isolation and culture from different species have been reported. However, there are no reliable methods for the large scale isolation and culture of the terminal segments of the pancreatic duct system. Acinar fragments of the hamster pancreas are isolated by partial digestion with collagenase. Culture is achieved by embedding in a matrix of rat-tail collagen …  Lire la suite

Sites contaminated with polyaromatic hydrocarbons (PAHs) pose serious health and safety risks to the surrounding environment due to their toxicity, persistence and accumulation in the environment. Because certain members of this class have been demonstrated to be both carcinogenic and mutagenic, PAHs are considered as environmental priority pollutants (US EPA). The studies in this thesis provide an efficient, economical and environmentally benign technique for the remediation of PAH contaminated soil/sediment by means of PAH mobilization with surfactant followed with a catalytic hydrogenation in supercritical carbon dioxide (scCO2). Catalytic hydrogenation of naphthalene, acenaphthylene, ancenaphthene, anthracene, phenanthrene, chrysene and benzo[a]pyrene over alumina …  Lire la suite

Chlorinated aromatic compounds are an important group of compounds. Many of them have been produced in large quantities and they are indispensable to technological and societal benefits. But regulatory agencies have tightened regulations on the use and release of chlorinated aromatic compounds because of the scientific understanding of their toxicity, persistence, behavior in the environment and their potential to cause adverse effects on the ecosystem and human health. Pentachlorophenol (PCP), octachloronaphthalene and decachlorobiphenyl are all highly chlorinated aromatic compounds, of which, PCP has been used mainly as a biocide. Octachloronaphthalene and decachlorobiphenyl don't have practical use, but their congeners have …  Lire la suite

Constant improvements in computer communications, microprocessors and operating systems are finally making wide-area public computing utilities (PCUs) a reality. The core idea of a CU is to connect resources that are geographically distributed and potentially heterogeneous into a single networked system such that clients can obtain on-demand the necessary resources for their computing needs from this system. Several PCUs have been created in the recent past using the Grid technology for both research and commercial purposes. Because PCUs often bring together resources from geographically distributed locations, they are ideally suited for applications that have geographically distributed resource demands. An example …  Lire la suite

The objective of this thesis is to demonstrate, through analysis of the current Canadian Copyright Act and related cases, how the rapid development of Internet technology has challenged the legal protection of musical works under Canadian copyright legislation and jurisprudence. Canadian government and courts have begun contemplating these issues and attempted to formulate constitutional reform policies and effective measures for Canada. These initiatives related to copyright protection of musical works reflect a sophisticated analysis of each participant involved in music transmission through the Internet and are unique in this way. More flexible business mechanisms may contribute towards the achievement of …  Lire la suite

La composition corporelle pendant la petite enfance est un facteur déterminant de la santé tout au long de la vie. Plusieurs études ont permis de constater que le statut maternel en acides gras polyinsaturés (PUFA) influence la composition corporelle du nourrisson. Par contre, il existe peu de données sur la relation entre le statut en PUFA du nourrisson et la composition corporelle. L’objectif de cette thèse est d’examiner en détail si la composition en PUFA de la membrane des globules rouges (RBC) du nourrisson est reliée à la composition corporelle infantile. Soixante-dix paires mère-nourrisson en santé ont été recrutées à …  Lire la suite

Accurate and efficient methods have been developed for the quantitative electron-induced X-ray microanalysis of homogeneous materials in order to calculate the chemical composition from the characteristic X-ray intensities measured using energy-dispersive spectrometry (EDS) or wavelength-dispersive spectrometry (WDS). However, for heterogeneous materials, quantitative X-ray microanalysis still faces some difficulties. For example, the accuracy of forward modeling, i.e., to predict X-ray emission with prior knowledge of the specimen and experimental setup, is influenced by the secondary fluorescence effect. Also, the complex structures of heterogeneous materials make it difficult to develop a universal inverse modeling algorithm to extract the compositional and structural information …  Lire la suite

This thesis discusses the design and implementation of a relational database programming language, focusing on the domain algebra for nested relations. While the relational algebra provides operations to manipulate relations as data primitives, the domain algebra allows the manipulation of the attributes of relations. With the nested relational model, the domain algebra subsumes the functionality of the relational algebra. The conventional relational operations (e.g. selection and projection) may be applied to the attributes of a relation. The domain algebra for nested relations has many advantages. For example, the domain algebra makes the nesting and unnesting of relations very easy. This …  Lire la suite

This thesis focuses on the design, implementation and evaluation of a coordinates-based mechanism to compute network positions of Internet hosts in the resource addressable network. This mechanism is based on absolute coordinates calculated from modelling the Internet as a D-dimensional Cartesian space. A small distributed set of infrastructure hosts called landmarks is chosen to first compute their coordinates and serves as a frame of reference for other hosts. I study two algorithms for landmark positioning: distributed spring algorithm and spring equilibrium algorithm. The position of the non-landmark host is calculated using a centralized algorithm. I also evaluate a schema to …  Lire la suite

When the isolated heart is perfused with a constant flow, the perfusion pressure (PI) can be considered to be the sum of those pressures required to overcome autoregulation (PA), critical closure (PCC) and the resistance of the relaxed vascular bed (PO). PA can be estimated from the difference between PI and the pressure obtained 10 seconds following a 30 second period of stop flow (PR). PA increases from 0 to 50 mm Hg with increasing flow. PR was found to be linearly related to flow with a positive pressure intercept on the pressure axis. This intercept was interpreted as PCC …  Lire la suite

Reed, Bruce Alan (Supervisor1)  Lire la suite

Anisotropic chalcogenide microsphere is introduced for coupling theoretical analyzing and coupling experiment. Whispering Gallery Modes (WGMs) of isotropic microsphere is introduced and the TE & TM WGMs dispersion relationship is derived from electromagnetic vector equations in the spherical coordinate. The Maxwell equations can be solved in 2D model for the 3D model of axisymmetric or Rotational symmetry isotropic microsphere. First 4 TE&TM WGMs are simulated in 2D model using finite-element weak method. The binding capability, mode volume V and quality factor Q depend on the refractive index and size of the microsphere. Plane wavefront light wave is assumed to propagate …  Lire la suite

L'augmentation rapide des réseaux sociaux en ligne a attiré un nombre croissant d'utilisateurs malveillants. Les spammeurs sociaux sont capables de compromettre la communauté en envoyant divers contenus dangereux. Au cours des dernières années, des chercheurs ont étudié plusieurs stratégies de détection de spam. Toutefois, beaucoup de méthodes de détection semblent inefficaces, car les spammeurs se développement constamment pour échapper à la détection. Dans ce mémoire, on cherche à concevoir un système de détection de spam plus fort qui rend difficile la fuite des spammeurs. Afin d'atteindre cet objectif, on fournit d'abord une analyse approfondie sur différentes propriétés des comptes de …  Lire la suite

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice. Although AF has been recognized and studied extensively since the early twentieth century, AF management is far from ideal. A better understanding of AF mechanisms is essential in order to improve treatment of AF. The objectives of this study were designed to determine the cellular, ionic, and molecular bases of tachycardia-related AF. To achieve our goals, we developed a dog model of tachycardia-related AF, and studied ionic and molecular determinants of atrial repolarization under normal physiological conditions, as well as the ionic and molecular determinants of tachycardia-induced …  Lire la suite

Cholesterol oxidase is a bifunctional flavoenzyme which catalyses the oxidation and isomerization of 3beta-hydroxyl steroids with a double bond at Delta5-Delta6 of the steroid ring. The FAD noncovalently-bound form of the enzyme obtained from Streptomyces sp. SA-COO was crystallized. The structure was solved by molecular replacement, and refined to 1.5 A resolution. The final model contains 498 amino acid residues, the FAD cofactor, and 662 solvent molecules. In addition, the H449N and E363Q mutants of this protein were crystallized. The structures were solved and refined to 1.8 A and 1.65 A, respectively. The superposition of the native structure with the …  Lire la suite

The influence of protein-calorie malnutrition (PCM) on the anti-inflammatory activity (suppression of carrageenan-induced paw edema and pleurisy) of salicylate was studied in Sprague-Dawley male rats. For this purpose, animals were fed a 21% (control) or a 5% (PCM) protein diet ad libitum or a control diet in restricted amounts (pair-fed). A significant increase in the anti-inflammatory activity of salicylate was observed in PCM but not in pair-fed rats. PCM caused a decrease in plasma salicylate (assayed by HPLC) concentration (due to increased synthesis of glycine conjugate and elimination), no change in tissue distribution, and a moderate decrease in serum protein …  Lire la suite

We implement a general procedure for incomplete data estimation problems proposed by Gu & Li (1998) and Gu & Kong (1998). The procedure can be used to find the Maximum Likelihood Estimate (MLE) or solve estimating equations in problems such as estimations with censored or truncated regression model, nonlinear structural measurement error model and random effects model. The procedure is based on the general principle of stochastic approximation (Robbins & Monroe 1951) and Markov Chain Monte Carlo method (Metropolis et al. 1953, Hastings 1970). A new stopping criterion is proposed and simulation studies indicate that the algorithm converges consistently to …  Lire la suite

The Enhanced Dynamic Wedge (EDW) is an intensity modulated radiation therapy technique found in certain linear accelerators used in radiation oncology. Invoking the EDW causes one collimating jaw to move across the field to produce a predefined wedged dose distribution. Measured dose profiles were compared with plans calculated by a treatment planning system for various fields. EDW fields were examined for various wedge angles currently available for clinical use. EDW fields for non-clinical angles, which are not currently available, were also produced by applying the ratio of tangents method and delivered with the use of the Dynamic Beam Delivery (DBD) …  Lire la suite

[...]In our detailed study of the synthesis, results dis_closed a number of difficulties encountered in the Reformatsky reaction and a seriousirregularity in the last step in the oxidation to the quinone. A compound, also a quinone, always appeared in the oxidation product as acontaminant but no mention of it was made in the original literature. Attempts were made, therefore, to determine the optimum conditions forsecuring the amphi-ohrysenequinone in good yield. In the following section we have presented a description of the work dealing with the Reformatskyreaction, the intermediate steps and the final oxidation. The evidence which ultimately led us to …  Lire la suite

Les chaises roulantes jouent un rôle important pour les gens présentant desdifficultés de locomotion. Cependant, les utilisateurs de chaises roulantes électriquesrapportent des accidents autant mineurs que majeurs. Le but de cette thèse est depromouvoir l’utilisation de technologies robotiques, plus précisemment la détectionà base de senseurs et la classification automatique d’activités dans le but de traqueret caractériser les activitées à bord de chaises roulantes intelligentes.Cette thèse présente une méthode pour détecter et classifier précisemment lesactivités des chaises roulantes à partir de données d’accéléromètre en utilisant desméthodes d’apprentissage automatique et de traitement de signaux. D’abord, uneplateforme de collecte de données enregistrant dans …  Lire la suite

La programmation orient´ee-aspect (POA) est un paradigme ayant pour but d’am´eliorerla modularit´e du logiciel en localisant les pr´eoccupations ´eparpill´ees dans des aspects.La refactorisation orient´ee-aspect ´etend les avantages de la POA par l’identification etl’encapsulation des pr´eoccupations existantes `a l’aide du forage d’aspects (aspect mining),et par leur refactorisation en aspects `a l’aide de transformations de code. Cependant,certains r´esultats du forage d’aspects ne correspondent pas `a des pr´eoccupations´eparpill´ees, et les languages aspects existants ne supportent pas la refactorisation de tousles pr´eoccupations en aspects. Cette th`ese d´ecrit une approche pour extraire les pr´eoccupations´eparpill´ees dans une forme qui se prˆete `a la refactorisation. Le processus …  Lire la suite

Jakobson, Dmitry (Supervisor1)  Lire la suite

Drew, R. A. L. (Supervisor)  Lire la suite

Cette thèse examine les implications pratiques de la reconnaissance étatique dans les relations internationales à travers une étude de cas approfondie de Taïwan. Bien que Taïwan ne bénéficie pas d’une reconnaissance formelle de la part de la communauté internationale, il participe activement aux affaires mondiales, remettant en question les hypothèses traditionnelles sur la nécessité de la reconnaissance pour l’exercice effectif de la souveraineté étatique. En recourant à une méthodologie contre-factuelle novatrice, la thèse construit un Taïwan « reconnu » - identique en tous points, à l’exception de son statut de reconnaissance internationale - et le compare au Taïwan actuel selon …  Lire la suite

Although the prevalence of severe neurocognitive impairment has fallen to below 5% since the introduction of combination antiretroviral therapy, HIV-associated neurocognitive impairment affects approximately 30-50% of adults living with HIV. Cross-sectional studies have identified associations between several sociodemographic or clinical risk factors with neurocognitive impairment in HIV, but the results have been inconsistent. A scoping review identified the three main methods to measure neurocognition over time in published longitudinal studies on risk factors of neurocognitive decline were single measures, neuropsychological test batteries or clinical evaluation; but there were no qualitative differences in reported study results between measurement strategies. To overcome …  Lire la suite

This thesis explores some of the legal implications of communication satellite constellations in Low Earth Orbit (LEO), specifically the satellite systems that plan to provide Personal Communication Services (PCS). The thesis begins with a brief history of long distance communications and their evolution from wire systems to space-based technology; the types of service providers and users are also indicated. Next, some of the perceived shortcomings of the current telecommunications technology are examined and suggestions are made as to how they could be overcome by LEO-based PCS satellites. The legal requirements, national and international, that need to be met to secure …  Lire la suite

Il est prévu que la demande pour les données sans fil continuera d'augmenter dans les décennies à venir. Un des facteurs principaux de cette croissance est la disponibilité des données dans les réseaux cellulaires. Les technologies 4G et LTE ont rendu possible la vidéo en direct et autres applications qui exigent beaucoup de débit dans les appareils mobiles. Il est prévu que la cinquième génération des réseaux mobiles ait besoin de fournir une capacité suffisante pour fournir la vidéo en direct de plus haute qualité pour plus d'appareils que les réseaux précédents. De plus, l'Internet des objets causera une augmentation …  Lire la suite

Durley, R. (Supervisors)  Lire la suite

Les salmonelles sont responsables de diverses maladies allant de la simple gastroentérite aux formes plus graves telles que la fièvre typhoïde. Les infections à Salmonella empruntent généralement la voie digestive et posent un problème de santé publique dans des régions du monde où il y a peu d'accès à l'eau potable. La sensibilité de l'hôte dans la réponse à l'infection peut s'expliquer par plusieurs facteurs localisés à l'interface de l'interaction hôte (gènes de prédisposition), pathogène (dose infectante, virulence) et environnement. L'utilisation du modèle murin par approche génétique a permis de mieux comprendre la physiopathologie des infections à salmonelles. Chez la …  Lire la suite

Cette étude a été entrepris pour examiner le fonctionnement adaptif chez les enfants ayant des délais développementals dans un contexte d'une intervention précoce. Les gardiens de 60 enfants ayant des délais développementals qui reçoivent des interventions précoces multidisciplinaires ont completés une évaluation standardisée du comportement adaptif de leurs enfants ainsi qu'un questionnaire démographique. Les variables adaptives ont étés analysées parmi 6 catégories diagnostiques pour déterminer si et comment les enfants ayant des délais développementals ont montré des profils adaptifs uniques parmi des contextes d'intervention précoce. Des profils distinctifs du comportement adaptif ont été dévoilés chez les enfants dans chaque groupe …  Lire la suite

The success of pregnancy is dependent on the adaptability of the maternal immune response, as the uterine environment must simultaneously permit the growth of a semi-allogeneic fetus while protecting against bacterial or viral infections. These transformations are initiated prior to implantation with the recruitment of leukocytes such as neutrophils, macrophages and regulatory T cells (Tregs) into the uterus. In particular, the immunosuppressive function of Tregs is critical to limit the extent of pro-inflammatory activation that arises from implantation. The following resolution of inflammation and sustained anti-inflammatory, tolerant and pro-angiogenic environment supports placental development and fetal growth until term. Indeed, dysregulated …  Lire la suite

L’analyse de la stabilité des systèmes linéaires boucle fermée à rétroaction négative est souvent effectuée avec la marge de gain et de phase définis par Bode. Cependant, ces marges devraient être utilisées uniquement pour les systèmes à phase minimale. Pour tous autres cas, le critère de stabilité de Nyquist peut être utilisé, mais les courbes de Nyquist sont difficiles à interpréter et n’inclue pas de concept de marge de stabilité. Si les marges de gain ou de phase sont appliquées pour analyser des systèmes à phase non minimale, les résultats peuvent être incorrects ou inconcluant.Cette thèse propose une nouvelle métrique …  Lire la suite