McGill University Thèses et mémoires par auteur commençant par Y

Les observations d’émissions décalées vers le rouge à 21 cm à ≤30 MHz sont cruciales pour sonder les âges sombres cosmiques de l’histoire de l’univers. Les âges sombres cosmiques ont commencé après la recombinaison et ont duré jusqu’à la naissance des premières étoiles. Les avant-plans galactiques, les interférences radioélectriques (RFI) d’origine humaine et les interférences ionosphériques posent des défis pour les observations à basse fréquence. Une mesure précise du signal de 21 cm nécessite le développement de cartes de premier plan précises puisque les émissions de premier plan galactique sont généralement beaucoup plus lumineuses que le signal cosmologique. ALBATROS (Array …  Read more

Kok, Robert (Internal/Cosupervisor2)  Read more

This dissertation examines the history of enslaved women and girls in British Mauritius from 1810­ to 1845. Through an exploration of British colonial interventions in slaveholding, this study focuses on the narratives of enslaved women and girls to reveal intersections between colonialism, motherhood, violence, and resistance to bondage. The British colonial government introduced a series of measures to reform slavery conditions in Mauritius prior to the Emancipation Act (1833), as they did in several Atlantic colonies. This included the establishment of a Commission of Eastern Enquiry to investigate slaveholding and manumission practices, and make recommendations related to the amelioration of …  Read more

Ce mémoire de maîtrise puise dans quatre romans afin de représenter la conscience dans la fiction irlandaise de 1922 à aujourd'hui, soit Ulysse de James Joyce (1922), «La trilogie: les filles de la campagne» de Edna O'Brien (1960-64), et The Infinities (2013) et The Singularities (2022) de John Banville. Ces romans s'inscrivent dans un continuum historique débutant parle néoréalisme d'Ulysses, passant par le modernisme des «Filles de la compagne», et se terminant pare le postmodernisme de The Infinities et The Singularities. Afin de comprendre comment ces romans représentent la conscience, je fais appel à une méthodologie narrative féministe. D'une certaine …  Read more

Le maïs Bt (Bacillus thuringiensis - Zea mays L.) est reconnu contenir plus de lignine et être plus résistant que les maïs hybrides conventionnels (NBt). Ces derniers sont affectés par la pyrale du maïs (European Corn Borer ou ECB, Ostrinia nubilalis H.), qui peut augmenter le dépôt de «lignine causée par le stress» dans les tissus et changer la décomposition des résidus de maïs. L'objective de cette thèse est d'évaluer les différences de composition en fibres, C et N entre les maïs BT et NBt, et d'étudier l'effet de l'herbivorie par ECB sur la décomposition les différentes parties résiduelles du …  Read more

Asghar, Anila (Supervisor1)  Read more

Synthesis of a novel conformationally rigid dimer 106 containing a cyclopropyl-phosphonate linkage is described. A novel 3'-phosphonate building block 105 is synthesized and characterized. During the synthesis of the common precursor 86, unusual base-promoted desilylation of epoxide 80 and vinylselenides 85 and 87 are reported. The instability of the tert-butyldimethylsilyl (TBDMS) and the tert-butyldiphenylsilyl (TBDPS) protecting groups may be attributed to the participation of the uracil C2-oxygen anion. The synthesis of a number of novel bicyclic phosphonate analogs 92b to 95b is described. In search of alternate cyclopropanation methods, dimesylate 113 was synthesized and characterized. Dimethyl methyl phosphonate anion treatment …  Read more

Many flow systems in engineering operations involve the simultaneous transport in pipes of a gaseous (or vapor) phase and a liquid phase. Examples of such systems are numerous; among them are water-steam mixtures in boiler tubes, petroleum liquids and their vapors in tube-stills, liquid-vapor mixtures in refrigeration systems, oil-laden compressed air, condensate return lines, gasoline engine manifolds, partial condensers in fractionation equipment, etc.  Read more

L'approche basée sur le temps de rétention et la masse déterminée de façon précise (ou approche AMT, Accurate Mass and Time tag) de la protéomique à haut débit fait appel à la RPLC (chromatographie liquide en phase inversée) couplée à la spectrométrie de masse de haute précision pour mesurer les masses et les temps de rétention des peptides trypsiques d'un mélange complexe. Ces mesures sont comparées aux masses et aux temps de rétention prévus de peptides d'une banque pour identifier les séquences associées. Cette thèse est constituée de deux articles de journaux, d'un article présenté dans une conférence et d'un …  Read more

This thesis consists of a critical introduction and three short Ii stories. In the introduction, an attempt is made to show in what specific ways the stories belong or do not belong to the tradition of modern realism and to the genre of the short story. Three elements are emphasized: the significance of commonplace events, the use of the first person narrator, and the effect of a longer, expanded short story. The stories, themselves, are meant to stretch the conventional limits of the short story not only in length, but also in the impression they make on the reader. Meaning …  Read more

A total of 596 milk samples with varying fat (3.0 to 4.0%) and protein (3.0 to 4.0%) contents were used to make laboratory-scale cheese and to determine coagulating properties. Higher levels of fat and protein in milk were associated with higher cheese yield. Milk protein has greater effect on cheese yield than milk fat. Adjusted yield increased by 1.91 and 1.29% for every percentage increase in the protein and fat of milk, respectively. Higher levels of fat in milk produced a cheese containing higher fat content and lower protein content. Similarly, higher levels of protein in milk produced higher protein …  Read more

Future wireless systems will have to support multimedia services such as voice, data and video. Issues in providing multimedia services on wireless systems include multiple access, bandwidth rationing, scheduling and power control. In this thesis, we address the last issue. CDMA is assumed to be the access method. Each of these services has different Quality of Service (QoS) requirements, maximum power and packet time-out constraints; in order to achieve the required QoS, they can alter their transmission. In this work, we present a novel Power Control With Priority Scheduling (PCWPS) algorithm for a wireless CDMA system, which achieves reliability and …  Read more

Les troubles du sommeil, y compris l'insomnie et les troubles du comportement en sommeil paradoxal (TCSP), ont reçu une attention croissante en tant que marqueurs/symptômes prodromiques (c'est-à-dire avant de poser un diagnostic clinique) de maladies neurodégénératives telles que le parkinsonisme et la démence. La connaissance des premières phases de la neurodégénérescence peut faciliter l’étudie de la maladie à ses débuts et la conception de futurs essais cliniques visant à prévenir ou à ralentir la neurodégénérescence précoce. Cette thèse est ainsi consacrée à l'étude des facteurs de risque et de la neurodégénérescence associés au TCSP (Section 1) et à l'insomnie (Section …  Read more

ABRÉGÉLes lymphocytes T régulateurs CD4+Foxp3+ (TREG) sont des pivots dans le maintien de la tolérance immunitaire aux antigènes autologues et agissent en tant que régulateurs des réactions auto-immunes. Il y a deux sous-ensembles de TREG : les naturelles (nTREG) qui se développent dans le thymus et les inductibles (iTREG) qui sont générés à partir des lymphocytes T effecteurs Foxp3- conventionnels (TCONV) en périphérie ou in vitro. Bien que les deux sous-ensembles requièrent l'expression de Foxp3 pour fonctionner, les lymphocytes iTREG régulent graduellement de manière négative Foxp3 in vitro et perdent leur capacité suppressive. En revanche, les lymphocytes nTREG présentent une …  Read more

Nous avons étudié l'effet des troncatures de l'Apolipoprotéine A-I (Apo A-I) sur la réponse immunitaire de l'hôte et le métabolisme lipidique dans la maladie de Chagas. Nous avons utilisé des modèles de souris transgéniques Apo AI humains pour imiter l'environnement Apo AI chez les humains et confirmé la présence de troncatures d'Apo AI précédemment observées in vitro et dans des échantillons de patients humains et ont étudié les différences dans l'activation immunitaire et le métabolisme lipidique en réponse à Trypanosoma cruzi (T . Cruzi) en présence ou en absence d'Apo AI humaine. Apo A-I est connu pour ses propriétés anti-inflammatoires …  Read more

La polykystose rénale autosomique dominante (ADPKD) est la maladie rénale génétique la plus répandue, causée principalement par des mutations du gène PKD1. L'ADPKD se caractérise par la formation et l'élargissement progressifs de kystes rénaux bilatéraux, processus provoqués par des mécanismes cellulaires dérégulés tels que l'hyperprolifération médiée par l'AMPc et la sécrétion excessive de liquide. La croissance progressive des kystes about à l'insuffisance rénale à l'âge moyen de 50 ans. Le seul traitement médicamenteux approuvé pour l'ADPKD, le Tolvaptan, est efficace seulement chez un sous-ensemble de patients. D'autres candidats thérapeutiques restent donc à explorer. Comme la croissance des kystes dans l'ADPKD …  Read more

Despite recent advancements in our understanding of its pathogenesis, measles virus (MeV) remains a major concern for human health. In developing countries, the impact of MeV infection is particularly dire in part due to vaccine quality issues and malnutrition. Although the mechanism remains poorly understood, the morbidity and mortality due to MeV infection in undernourished children can be significantly improved by vitamin A (VA) supplements. Small animal models can be very helpful to better understand the activity of defined micronutrients in viral infection. Unfortunately, there is no appropriate small animal model for MeV infection due to the limited host tropism …  Read more

Les signaux vibrotactiles sont omniprésents dans la vie quotidienne. Ils se manifestent soit quand on manipule les objets soit lorsque l'on touche des machines. Afin de donner aux "systèmes ambiants" la possibilité de communiquer aux utilisateurs par l'haptique, les signaux vibrotactiles s'avèrent être un moyen efficace, tant au point de vue de leur perception que de la consommation énergétique. fr Les téléphones portables sont, de loin, les appareils ayant des capacités haptiques les plus communs. Ils sont munis de moteurs vibrants ayant une bande passante limitée. Nous avons réalisé un transducteur vibrotactile à large bande passante et qui permet de …  Read more

The MicroTactus is an instrument designed to detect signals arising from the interaction of a tip with soft or hard objects and to magnify them for haptic and auditory reproduction. An enhanced arthroscopic surgical probe was developed using an accelerometer and a custom-designed actuator for haptic feedback. Measurements were made to characterize the device and the results showed that numerous factors such as gripping method and gripping force influenced the system response in a complicated manner. The device was tested with the task of detecting surface defects of a cartilage-like material. Subjects were asked to detect the cuts of different …  Read more

Waldispuhl, Jérôme (Supervisor1)  Read more

This thesis presents a theoretical approach to Ostwald ripening of droplets in arbitrary dimensions. A mean-field theory is constructed to incorporate screening effects among the competing droplets. The mean-field equations are solved to all orders in the volume fraction to provide analytic expressions for the coarsening rate, the droplet distribution function, and the time-dependent droplet number. These results are in agreement with experiments in three-dimension and with very large scale and extensive numerical studies in both two and three dimensions undertaken in this thesis. The numerical study also provides the time evolution of the structure factors, wherein lengths scale with …  Read more

The ornithine decarboxylase (ODC) and growth hormone (GH) genes are candidate genes for milk production traits in dairy cattle. In this study, the bovine ODC gene was cloned and characterized, followed by studies of genetic variations of the ODC and GH genes in Holsteins. A cDNA coding for bovine ODC was first isolated and analyzed. The clone (1758 bp) consists of 5’-and 3’-untranslated regions of 185 and 187 nucleotides, respectively, and an open reading frame of 1383 nucleotides encoding an ODC protein of 461 amino acids. Cloning and sequence analysis of the ODC genomic gene (9452 bp) revealed that the …  Read more

Mili, H. (Supervisor)  Read more

Detecting (and recognizing) human arm motion in a typical classroom environment is a challenging task due to the noisy and highly dynamic background, varying light conditions, as well as the small size and multiple number of possible matched objects. A robust vision system that can detect events of students' hands being raised for asking questions is described. This system is intended to support the collaborative demands of distributed classroom lecturing and further serve as a test case for real-time gesture recognition vision systems. Various techniques including temporal and spatial segmentation, skin color identification, as well as shape and feature analysis …  Read more

Drosophila development has provided a useful model system to study the molecular mechanisms that regulate neurogenesis. Recently much progress has been made in our understanding of how neural progenitor cells undergo commitment and become mature neurons. Studies have shown that a series of transcription factors plays fundamental roles in these neuronal developmental events. From Drosophila to mammals, evolutionarily conserved molecules regulate similar biological processes. The major hypothesis advanced in this thesis is that mammalian homologues of the Drosophila protein Groucho, namely the TLE proteins, share a conserved function in the regulation of mammalian neurogenesis. To investigate the molecular mechanisms regulating …  Read more

Designers hold primary responsibility for shaping the user interface (UI) and user experience (UX) of a product, a task that goes beyond aesthetics and usability when users interact with technology, but also includes the privacy outcomes of users experience. Previous studies on enhancing privacy for technological products primarily focused on the roles of developers—understanding their needs and challenges—but limited effort is devoted to examining how UI/UX designers consider and approach privacy in their work. Through 12 semi-structured interviews, we explore the perceptions, influencing factors, challenges, and adaptive methods of UI/UX designers toward the implementation of privacy. Our study reveals how …  Read more

Dumont, Marie-Josée (Internal/Cosupervisor2)  Read more

Complementary Metal-Oxide-Semiconductor (CMOS) based sensor systems continue to play an important role in various biomedical, chemical, industrial, food safety, national security and defense, and environmental applications. This is because CMOS fabrication processes would allow one to produce miniaturized systems with low cost, low power and mass-producibility. This dissertation deals with the development of integrated CMOS optical and CMOS electrochemical sensor microsystems for biochemical sensing applications for monitoring of oxygen and bacteria. The CMOS optical sensor microsystems developed as part of this dissertation are based on the luminometric intensity and lifetime measurement techniques and use sol-gel derived xerogel based sensing elements …  Read more

Le gène Cut homeobox 1 (CUX1) code pour plusieurs isoformes avec des activités bicohimiques et biologiques distinctes. Afin the comparer le potentiel oncogénique de certaines isoformes dans la glande mammaire, nous avons utilisé la méthode de transgénèse spécifique pour insérer les transgènes dans le locus hprt. Chaque transgène comprenait les séquences codantes d'une isoforme particulière sous le contrôle transcriptionnel de séquences régulatrices provenant du " Mouse Mammary Tumor Virus (MMTV). Dans cette étude, j'ai caractérisé le phénotype des souris de la souche FVB qui portait le transgène MMTV-p200 CUX1. Ces souris ont développé des tumeurs mammaires avec une pénétrance de …  Read more

Cette thèse se compose de trois essais qui étudient les problèmes d'inférence dans l'évaluation des prévisions macroéconomiques avec des données en temps réel. Le premier essai (chapitre 2) propose une approche d'amorçage par blocs pour l'inférence hors échantillon lorsque des données en temps réel sont utilisées pour produire des prévisions. En particulier, nous établissons sa validité asymptotique de premier ordre pour les tests de capacité prédictive de type West (1996) en présence de révisions régulières des données. Cela permet à l'utilisateur de mener une inférence asymptotiquement valide sans avoir à estimer les variances asymptotiques dérivées de l'extension de West (1996) …  Read more

The usual practice of smelting copper is to smelt for matte first. [...] Cutting down the copper content of slag by a few one-hundredths percent does not seem important at first glance. Since an enormous amount of slags is produced, its economic significance, however, can not be too over-estimated. It is the aim of the present investigation to throw some light on slag losses of copper. In view of the complexity of the problem, attempts are made to eliminate variables as much as possible. In ferrocalcic-silicate slags produced from matte-slag smelting, answers are sought for (1) whether oxidized copper could …  Read more

Recent studies have demonstrated that multivariate machine learning algorithms can decode the orientation of grating stimuli from coarsely sampled (3×3×3 mm3) functional magnetic resonance imaging (fMRI) data. Unraveling the mechanisms underlying decoding of information conveyed in the fine scale cortical organization of orientation preference will enable informed search for other fine scale organizations in relatively unknown areas such as the frontal cortex. We therefore aimed to analyze the mechanisms underlying decoding of information conveyed by orientation columns and maps. To this end, we have analyzed contributions from four out of the six hypothesized mechanisms as candidate contributors to the decoding …  Read more

An associative memory, unlike conventional memory systems, is a device or data structure that maps input-output patterns directly, without the need to construct an explicit address before retrieving the information content. The retrieval complexity grows in the data dimension, independent of the amount of data stored. Recently Gripon and Berrou propose a new type called clustered sparse associative memory (CSAM), which adopts a particular sparse encoding and non-linear iterative retrieval algorithms. The construct, extremely resilient to noise and errors, is able to store and reliably retrieve considerably more messages than other models.This thesis comprises three main parts. First, we implement …  Read more

Data from nine smoke sampling stations in the Montreal area showed high smoke concentration (~2 Coh) for 5-15% of the time during three winter months. A tenth station in the central downtown area showed highconcentrations 50% of the tille, with a mean value of 2.2 Coh. In this downtown area, the rate of smoke production often appeared more daminant than the meteorological conditions in detennining the pollution level.[...]  Read more

Plasmodium chabaudi AS infections in mice result in lethal and non-lethal infections in a strain-dependent fashion. Resistant C57BL/6 mice exhibit moderate levels of peak parasitemia and anemia and survive the infection. Susceptible A/J mice develop significantly higher parasitemias, severe anemia and succumb to infection. Resistance is controlled by a single or tightly linked, dominant, autosomal, non-H-2 linked locus(i), and is associated with the development of enhanced splenomegaly during infection and enhanced reticulocytic response to phenylhydrazine-induced hemolytic anemia. In this thesis, the relationship between the splenic erythropoietic response and resistance to infection is examined. Impairment of splenic erythropoiesis is demonstrated in …  Read more

In the early 1900's, investigators (1-6) using ammonium sulfate for the precipitation of serum proteins established an association of lipids with the serum globulins. Upon acidification of a solution of horse serum globulins half-saturated with ammonium sulfate from neutral pH to pH 3.9, Macheboeuf isolated what is now regarded as the first well defined lipid-protein complex of constant composition (5). [...]  Read more

Botulinum A toxin (BTX) has become increasingly recognized as a treatment option in the management of spasticity in children with cerebral palsy (CP). Preliminary evidence suggests that certain baseline characteristics of the child may affect responsiveness to BTX. However, the contribution of these factors has not been fully elucidated. The primary objective of the study was to examine whether specific intrinsic and extrinsic characteristics of the child were associated with responsiveness to BTX. The results indicate that age, number of treatments, parenting stress and child's motivation were associated with the degree of change in gait pattern, level of ambulation, gross …  Read more

Sporocytophaga strains were isolated from soil and manure and the bacteria were purified by plating enriched cultures on glucose agar. The effects of nitrogen compounds, carbohydrates and growth factors, on the metabolism of the isolated strains were studied. Glucose, mannose and cellobiose were the only carbohydrates utilized by the cellulose decomposing Sporocytophaga strains. High concentrations 4.5 per cent, M/4 of glucose inhibited glucose but not endogenous respiration. The optimum glucose concentration for strain 5-80 was M/200. [...]  Read more

Soundless Chemical Demolition Agents (SCDA) are powdery cementitious substances that, when combined with quicklime (CaO), produce a substantial increase in volume due to chemical reactions and expansive pressure. SCDA has been commonly employed in civil engineering to demolish concrete foundations when the use of explosives is prohibited or restricted. However, the potential application of SCDA in mining, specifically for breaking oversized boulders under sub-zero Celsius conditions remains relatively unexplored. This study aims to investigate the effectiveness of SCDA as an environmentally friendly alternative to secondary blasting in cold climate conditions. Laboratory tests were conducted using concrete and granite blocks with …  Read more

Antel, Jack P. (Supervisor1)  Read more

Brox, Alan (Advisor)  Read more

L'irrigation à débit variable (IDV) est une technologie émergente qui optimise la consommation énergétique et en eau et augmente les rendements des cultures, tout en minimisant les impacts environnementaux. Les objectifs de cette recherche étaient donc évaluer la performance de l'IDV, évaluer la variabilité spatiotemporelle des champs agricoles pour délimiter des zones de gestion d'irrigation, quantifier le potentiel en économie énergétique et en eau de l'IDV, et les avantages de la productivité des cultures de l'IDV pour deux types de cultures dans le sud de l'Alberta. Cette étude inclut une expérience sur le terrain d'une durée de quatre ans, entre …  Read more

The Large Hadron Collider at CERN, Switzerland, was built to both refine current Standard Model measurements, as well as discover new physics beyond the Standard Model. Using data from the general-purpose ATLAS detector, we take a step towards answering one of these questions: are quarks point-like, or do they themselves have sub-structure? By investigating the angular correlations in photon+jet events we address this question. The final goal of this thesis was to produce a feasible method to test deviations from the Standard Model using 2012 ATLAS data. A new data-driven background estimation analysis technique was developed to test for significant …  Read more

The myth of Circe and Odysseus has been told, interpreted and retold from Homer's time to the present. This thesis begins with a detailed study of Homer's balancing of positive and negative elements of the myth and argues that Homer's Circe is connected with age-old traditions of goddess worship, particularly of Artemis of Ephesus. Chapters III and IV investigate the cultural context in which the purely negative Circe of the Homeric allegorists developed and how this allegorical Circe affected works by other ancient writers, particularly Virgil and Ovid. Later chapters demonstrate how this negative allegorical view of Circe prevailed through …  Read more

Spring-born ram lambs were used to examine: (1) sexual maturational changes in LH, FSH and prolactin (PRL) secretion, testicular gonadotropin receptors, and testicular size and function; (2) predictability of yearling ram reproductive function from juvenile testicular size and reproductive hormone measurements. Despite continuous increases in testis size, serum LH-profile characteristics became greatest between 2 and 4 months and declined thereafter. However, LH-peak frequency increased by about 2-fold between 6 and 7 months; this was associated with marked increases in testosterone (T) secretion and spermatogenic function. Mean FSH and PRL levels were maximum at 2 months and 3 to 5 months, …  Read more

Daycare of children includes a wide variety of formal and informal arrangements which parents choose for the care of their children within or outside of their homes during daytime. Although needs tor supplementary,r child care arises out of many family circumstances, the most frequent cause ls maternal employment.  Read more

La croissance exponentielle des appareils sans fil a conduit à une demande accrue de transmission de données à haut débit, exacerbant les pénuries de bande passante et créant des défis dans la gestion des connexions entre les stations de base et les utilisateurs déployés de manière dense. La technologie massive à entrées multiples et sorties multiples (mMIMO) répond à ces défis en utilisant des réseaux d'antennes phasées à grande échelle pour servir simultanément plusieurs utilisateurs. Cependant, le rayonnement non intentionnel dans des directions non ciblées entraîne des interférences multi-utilisateurs (MUI) et dégrade les performances globales du système. Les méthodes actuelles …  Read more