McGill University Thèses et mémoires par auteur commençant par J

Kris J J Jacobs (Internal/Cosupervisor2)  Read more

Chiral auxiliary 1,2-O-cyclopentylidene-5-deoxy-5-isopropylamino-alpha- D-xylofuranose 51 and its enantiomer 52 were synthesized from D-xylose and L-xylose respectively and treated with PC13 to form cyclic phosphochloridites 58 and 67, and then reacted with 5'-O- t-butyldimethylsilylthymidine to give diastereornerically pure cyclic phosphoramidites 60 and 68. They were coupled with 3'-O-t-butyldimethylsilylthymidine in the presence of 2-bromo-4,5-dicyanoimidazole 46 as catalyst, and then sulfurized with Beaucage's reagent to form protected dithymidine phosphorothioates 62 and 72 stereoselectively. After deprotection, Sp and Rp dithymidine phosphorothioates 65 and 66 were obtained respectively in 98% diastereomeric excess. The mechanism of the coupling reaction which involves only one inversion in the …  Read more

Immersive video communication has emerged as a transformative technology for remote interaction, but its widespread adoption on daily devices is hindered by challenges including privacy risks, hardware dependencies, and inefficient resource utilization. This thesis addresses these barriers through three interconnected research directions, developing innovative systems to make immersive communication more accessible, secure, and efficient.First, a privacy-preserving gaze-assisted immersive video streaming framework is proposed, integrating three core modules: Privacy Protection, Viewport Prediction, and Bitrate Allocation. The Privacy Protection module introduces a tailored differential privacy approach accounting for spatial-temporal correlations in viewport/gaze data, using Gaussian noise and Fourier perturbation to safeguard user …  Read more

Liu, Xue (Internal/Supervisor)  Read more

The global push to transition from fossil fuel-based resources towards more sustainable alternatives has greatly increased over the turn of the century. Within this space, sustainable functional materials development has sparked intense interest in both academia and industry alike, fostering interdisciplinary research on the borders of materials science, chemistry, and engineering. One major area of sustainable materials development relies on using more benign resources. However, attention must be taken in ensuring that the methods taken to create such materials are sustainable, while allowing for reliable and competitive downstream application. In this respect, nanomaterials synthesis in particular must also heed these …  Read more

Dust of Fire est une pièce écrite pour grand orchestre : bois par 2, 4 cors, 2 trompettes, 2 trombones, tuba, timbales, 3 percussionnistes, harpe, piano, célesta, et cordes (16-14-12-10-8). Cette œuvre est la continuation de ma recherche sur la création de liens entre des images visuelles et des environnements sonores en usant de textures musicales spécifiques dans la partition. La pièce est entièrement construite autour de deux textures elles-mêmes issues de deux contours symbolisant la poussière et le feu. Le feu et la poussière symbolisent respectivement les structures de pouvoir et l’oppression. La forme de cette œuvre est A …  Read more

Juncker, David (Supervisor1)  Read more

The central nervous system is extremely sensitive to global and local changes in pH, which are important to neural survival and excitability. Ion transporters that move acid-base equivalents regulate cellular pH and can therefore influence neuronal homeostasis. The SLC9a family of mammalian alkali cation-proton exchangers, commonly known as sodium-proton exchangers (NHE), are transmembrane proteins that normally catalyze the electroneutral exchange of extracellular sodium (and/or potassium) for intracellular protons. Thus, NHE contribute to the regulation of intracellular pH and volume homeostasis. The NHE family consists of eleven isoforms that have differential tissue distributions, subcellular locations and regulatory functions. Within the nervous …  Read more

Timely and accurate nowcasting of hail events has significant societal and economic benefits yet remains a challenge due to the limitation of existing numerical weather prediction models in resolving mesoscale convective weather and the complex interactions of factors relevant to hailstorms. The evolution of hail in thunderstorms is a complex process that depends on several interacting factors, including atmospheric instability, updrafts strength, supercooled water content, and dry air in the troposphere. We investigated the possibility and skill of a machine learning method called Random Forests (RF) to nowcast hailstorms. This study applies the RF algorithm to nowcast hail in the …  Read more

Background: Accurate and timely detection of adverse health events across healthcare institutions, such as deep vein thrombosis (DVTs), is essential for both patient safety and the reduction of health care costs. Current methods are time consuming and inefficient. However, with the advent of electronic health records (EHR), clinical narratives are becoming readily available for automated analysis through machine learning methods.Objective: The aim of this project was to use two distinct analytic methods, logistic regression (LR) and random forest (RF), to assess the accuracy of identified unigrams and bigrams in radiological exams that are descriptive of DVT. Methods: A random sample …  Read more

Peterson, Alan (Supervisor)  Read more

Mitchell, Claudia A. (Supervisor2)  Read more

Hydrostatic pressure has been demonstrated to induce major changes in secondary structure of whey proteins resulting in an increased digestibility in vitro, and possibly an improvement of the glutathione (GSH) inducing effect of whey proteins in vivo. Micro filtration and ion-exchange, two commonly used processing techniques in whey protein manufacture, generate whey proteins with different compositions. Two animal studies were designed to compare the digestibility and GSH inducing effects of whey protein isolates (WPIs) treated with three repeated pulse cycling of pressure (3-cycle) or single pulse of high pressure (1-cycle) and pressurized microfiltrated and ion-exchange WPIs. The results indicate that …  Read more

Friedreich ataxia (FRDA) is a neurodegenerative disorder caused by reduced expression of the mitochondrial protein frataxin and characterized by a debilitating loss of coordination. In yeast, complete loss of frataxin causes mitochondrial iron accumulation and oxidative stress. Although FRDA cells exhibit impaired respiratory complex activity and greater sensitivity to hydrogen peroxide-induced apoptotic cell death, an increase in steady-state mitochondrial iron levels has not been conclusively shown. Pulse-chase experiments using FRDA fibroblasts suggest that severe disturbances in iron metabolism occur following supplementation with iron levels sufficient to overwhelm residual frataxin in these cells. Moreover, frataxin appears capable of forming high molecular …  Read more

Mahajan, Aditya (Supervisor2)  Read more

ABRÉGÉ Le glycérol est le principal sous-produit de la production de biodiesel. Enterobacter aerogenes a une capacité connue à convertir le (glycérol) en hydrogène et en éthanol au cours d'une fermentation. Afin de démontrer le potentiel d'un procédé en continu de valorisation du glycérol, les conditions optimales de culture ont été déterminées dans des bouteilles afin d'optimiser le rendement en hydrogène et puis appliquées à un bioréacteur de 3.6 L. Les conditions de culture optimales, déterminées à l'aide de la méthodologie de réponse de surface de Box-Behnken, sont un volume d'inoculation de 18%, une concentration d'oxygène de 7.5% lors du …  Read more

Neurodegenerative diseases are a vast grouping of conditions which invariably result in the loss of neurons. This loss is irreversible, and is one of many reasons why these diseases are notoriously difficult to treat. However, a glimmer of hope rests with the neurotrophins and their receptors, a family of proteins highly involved in survival, differentiation, and migratory processes. Employing trophic factors therapeutically has been a grand failure, despite a deeper understanding of their biology as well as methods for their delivery. By and large, bulky proteins possess poor pharmacological properties, many of which are inescapable. Slow and unpredictable diffusion, instability, …  Read more

Joos, Geza (Supervisor2)  Read more

A fundamental question concerning the legal effects of the notwithstanding clause is whether courts could conduct judicial review of legislation invoking the clause. The received wisdom on this question has been that the notwithstanding clause precludes judicial review. But in recent years, scholars have argued in different ways that the notwithstanding clause permits judicial review. This thesis critically builds on the arguments that the notwithstanding clause permits judicial review of protected legislation. It points out the problems with those arguments and proposes a revised theory of the notwithstanding clause which addresses the difficulties with those arguments. Along the way, it …  Read more

Ericsson, Jan Edvard (Supervisor2)  Read more

La création de catégories de différences raciales biologiques telles que le teint de la peau et la texture des cheveux étaient des sites clés par lesquels l’humanité des personnes Noires était refusée et que les esclavagistes blancs utilisaient pour positionner les Africains comme inférieurs. Comment les femmes Noires assujetties dans l’Empire français ont-elles maintenu leurs pratiques de coiffure et d’habillement et qu'est-ce que cela signifie qu'elles l'ont fait face à de multiples obstacles? Cette thèse examine les pratiques vestimentaires, de soin capillaire et de coiffure des femmes Noires au XVIIe et XVIIIe siècle dans l'Empire français, en particulier la Nouvelle-France/Québec, …  Read more

Through the close reading of four poetry collections by Patrice Desbiens (L'Homme invisible / The Invisible Man, Poèmes anglais, Le Pays de personne et La Fissure de la fiction), this thesis aims to show how the particular use of metaphor and simile participate in a global strategy of irony in the poet's work. According to Northrop Frye's literary theory, the literature we call "ironic" separates the writer's mind from a world of frustration and absurdity. The writer's imagination reconfigures the outside world and envisions a new reality that suits the writer's ideals. This reinterpretation of reality is accomplished by associative …  Read more

This thesis reports on an investigation of unstable detonations near the limits of gaseous mixtures, which has been carried out in a continuous loop of 5 cylindrical tubes, of 11 m length each, of decreasing diameter (from 152, to 38 mm). The experiments were carried out for different mixtures of hydrogen, ethylene and propane in air, and also hydrogen-oxygen with argon as diluent. It is reasonable to seek a dependence of detonability limits on the geometry length scale of the system, i.e. the tube diameter d, and on the characteristic of the cell width $ lambda$. A d/$ lambda$ criterion …  Read more

Thermal processing involves application of heat to destroy pathogenic microorganisms of public heath concern and to reduce the activity of microorganisms and enzymes that spoil the food. However, the technique is associated with considerable degradation of taste, color, texture, flavor and nutritional quality of processed foods. Data on kinetics of changes in quality factors and their temperature dependence, as well as the heat penetration behavior of the food during processing are necessary to predict and optimize the extent of quality retention. The objectives of this study were: (a) to evaluate the kinetics of thermal softening, color degradation and loss of …  Read more

Rehn and Hebard (1915) listed forty-seven names in synonymy under the original name, Acheta assimilis Fabricius, 1775. Recent studies by Fulton (1952), Alexander (1957), Alexander and Bigelow (1960) and Bigelow (1958 and 1960) have revealed the presence of a number of distinct, reproductively isolated species. All these writers recognized biological evidence as being of primary importance in taxonomic studies of American field crickets.  Read more

Mallory, J. R. (Supervisor)  Read more

This work is an attempt to evaluate the contribution of Jean Baptiste Meilleur to the development of education in Quebec. It was suggested to me several years ago that I should make a translation of Meilleur’s Memorial de lfEducation which, in addition to containing a history of educational institutions up to his time, reveals many of the difficulties and problems with which he was faced as first Superintendent of Education for Lower Canada 1842-55* However, on becoming familiar with this period of history whence our present educational system is derived, I was prompted to make the present study. [...]  Read more

Mutations in the parkin gene result in early-onset, autosomal recessive Parkinson's disease (PD). Parkin is an E3 ubiquitin (Ub) ligase that promotes the covalent attachment of Ub to specific substrate proteins that are targeted for proteasomal degradation. Here, we identify the synaptic PDZ protein PICK1 (Protein Interacting with C-Kinase 1) as a novel substrate for parkin-mediated ubiquitination. We establish that the PDZ domain of PICK1 interacts with the extreme C-terminus of parkin, which encodes a type II PDZ-binding motif. We demonstrate in vitro that parkin directly ubiquitinates wildtype PICK1 but not a PDZ domain mutant, PICK1 KD/AA. In cells, ubiquitination …  Read more

To improve the mechanical properties of the most widely used Al-Si foundry alloys, small amounts of magnesium are often introduced. However, the effect of magnesium on the eutectic microstructure is unclear. The aim of the present work is to investigate the effect of magnesium on the eutectic microstructure and to clarify its role in the silicon solidification. Experiments were performed on hypoeutectic and eutectic alloys (Al-7%Si, Al-11%Si, Al-13%Si and 413.2 alloys). Assessment of the eutectic microstructure was done using thermal analysis and metallography. The silicon phase was quantified by image analysis in terms of its perimeter, shape factor and aspect …  Read more

Lower Earth orbits (LEO) have become the residence for a significant number of large space debris, most of which are defunct satellites and rocket upper stages. The said debris jeopardize regular spacecraft operations in LEO and act as sources of smaller debris as a result of collisions and degradation. To mitigate the adverse effects of space debris and to remediate the LEO region, active debris removal (ADR) missions have been proposed. A mission plan for de-orbiting multiple pieces of large space debris is formulated and evaluated. Within this mission plan, low thrust orbital manoeuvres are used to achieve the necessary …  Read more

In this thesis, I discuss how practitioners of martial arts in the Republican era of China were engaged in a process of reinventing what embodied the field of martial arts during a time when physical culture was treated as an instrument of nation-building in response to colonial discourses and the process of modernization. Martial arts were repositioned from being a loosely associated field of practice for people who engaged with a set of combative skills that focused on weapons training that championed archery and spear fighting, towards being a recreational activity with a formalized body of knowledge, skills and practices …  Read more

A microscopic model is presented which describes in some detail a possible mechanism for vortex states enclosing trapped flux in simply connected superconductors. The energy associated with such states is calculated by using a formalism similar to the Bardeen - Cooper - Schrieffer formalism but using cylindrical rather than plane waves as the basis. [...]  Read more

The dissertation deals with four issues affecting Employer Sponsored Pension Plans: (a) the rationale for their existence and growth, (b) the impact of taxation on funding decisions, (c) the development of an investment model for such funds, and (d) the evaluation of the historical investment performance of 83 Canadian pension funds. The proposed investment model integrates the fund's assets with the firm's assets. It is operationalized for four Canadian firms, using a universe of 192 common stocks and eleven bond portfolios. The results indicate that the optimal pension fund is firm-specific, in terms of both asset mix and security selection. …  Read more

The gut microbiota provides important functions integral to host health. Metabolism of microbiota-accessible carbohydrates leads to the production of short-chain fatty acids (SCFAs), which are anti-inflammatory and provide energy to intestinal epithelial cells. Bacterial activity is therefore important for gut homeostasis. Here, we study bacterial activity by using bacterial physiology, specifically relative nucleic acid content, as a proxy. Data from other bacterial systems have suggested that high nucleic acid-containing bacteria (HNA) are more metabolically active than low nucleic acid-containing bacteria (LNA) within a given ecosystem. Thus, we hypothesized that relative nucleic acid content is connected to bacterial activity in the …  Read more

[...]The manner in which the density of a gas depends on its pressure and temperature has been studied ever since chemistry became an exact science.[...] With a view to the low pressures at which the density measurements, given later in this thesis, were made, only those methods employed atcorresponding pressures, and yielding results of fairly high precision, will be given. [...]  Read more

Contexte. L'atrésie de l'œsophage (AO) est une anomalie congénitale rare souvent accompagnée de malformations congénitales supplémentaires, ce qui pose d'importants défis pour les résultats des patients. Malgré des progrès notables dans le traitement, les patients atteints d'AO sans comorbidités présentent encore des taux de mortalité significativement élevés et souffrent de complications à long terme qui affectent considérablement leur qualité de vie. Cette étude visait à étudier l'impact de l'âge gestationnel sur les complications gastro-œsophagiennes et respiratoires après réparation de l'AO. Objectif Étudier l'impact de l'âge gestationnel sur l'incidence des complications gastro-intestinales et respiratoires au cours des 5 premières années après …  Read more

L’industrie mondiale du transport aérien s’appuie fortement sur les données pour améliorer la sûreté, la sécurité et l’expérience de voyage tout en abordant les problèmes environnementaux et sanitaires. Cependant, la transmission cruciale des données des passagers à des fins de sécurité des frontières et de lutte contre le terrorisme est compliquée par des réglementations nationales incohérentes et parfois contradictoires en matière de protection des données. Ces réglementations ne sont pas adaptées à la nature unique de l’aviation civile internationale, ce qui crée des défis considérables pour les gouvernements et les transporteurs aériens en termes d’application et de mise en œuvre. …  Read more

Un specialiste de marketing doit faire face a un aboutissement fondamental lorsquTil met au point une strategie de marketing: un choix entre d’une part l’adoption d’une strategie mettant en valeur lfimage d!un certain produit, comme le recommende David Oglivy, et d*autre part 1Tinfluence du choix du consommateur au moyen d!une proposition de vente exceptionnelle, comme le recom- -mende Rosser Reeves. En termes plus simples, lTattrait de l’emotionnel contre l’attrait du rationnel/fontionnel. Afin de l1aider a prendre cette decision, le specialiste de marketing doit etudier les motivations du consommateur et determiner pour la categorie de son produit/service si le choix du …  Read more

La méta-analyse sur des données individuelles des patients (IPD-MA) est une approche de plus en plus populaire à cause de ses bonnes propriétés analytiques. L'IPD-MA des études observationnelles fait face au problème des variables confusionnelles, lesquelles peuvent mener à un estimateur biaisé de l'effet de traitement. Une meilleure alternative consiste en l'appariement des scores de propension pour régler le problème des facteurs confondants. Jusqu'à très récemment, plusieurs approches basées sur cet appariement ont été utilisées pour les données en grappes. L'IPD-MA peut être considérée comme une approche en grappes à deux niveaux où les méthodes basées sur l'appariement sur les …  Read more

A two-step non-asymptotic approach for parameter and state estimation in ReproducingKernel Hilbert Space (RKHS) is presented in this thesis. It begins with the understandingand derivation of double sided kernel representation for a fourth order linear system andproceeds into discussing and developing methods for state and parameter estimation fromsingle noisy realizations of the system output on a time interval [a; b]. Once the parametersare estimated the output is reconstructed by projection onto the span of fundamentalsolutions and this in turn is used to reconstruct the time derivatives of the system output  Read more

Ngadi, Michael O. (Supervisor1)  Read more

In a group of predominantly light smokers (N = 10), EEG was recorded before and after cigarette smoking both during rest, and while engaged by two cognitive/perceptual tasks (i) the video game Tetris, and (ii) a computerized reverse mirror drawing task. Increases in beta2 power occurred 0-2 minutes after smoking, which were significant in half the subjects. Significant decreases in peak alpha power and an increase of 0.7 Hz in peak alpha frequency existed 1-2 minutes after smoking. Alpha frequency and power were examined again 11 minutes post-smoking and were found to still be altered, although this did not reach …  Read more