McGill University Theses and dissertations by author name (P)

The lectins Ulex europaeus 1 (UEA 1), Ricinus communis 1 (RCA 1), Wheat Germ Agglutinin (WGA), and Lens culinaris agglutinin (LCA) which are specific for L-fucose, D-galactose, N-acetylglucosamine, and D-mannose respectively, have been used to localize cytochemically the presence of these sugar residues in certain human, mammalian, and amphibian cell types. Thin sections of Lowicryl K4M-embedded human distal colon, rat duodenum, and frog dorsal root ganglion were incubated with UEA 1-gold, RCA 1-gold, WGA/ovomucoid-gold, or LCA-gold. UEA-1, RCA-1, and LCA binding sites were present in the nuclei of human colonic cells, rat duodenal goblet and columnar cells and frog dorsal …  Read more

Les gènes codants pour l’ADN ribosomique (ADNr) sont transcrits dans le nucléole pour produire l’ARN ribosomique (ARNr). Ils sont répétés en tandem et constituent des régions instables du génome. Les cassures double brin de l’ADN (CDB) générées à l’intérieur des gènes ADNr provoquent une réponse cellulaire unique impliquant une forte répression transcriptionnelle et une ségrégation de l’ADNr endommagé dans des structures de coiffes nucléolaires. Ce processus est coordonné par la protéine d’échafaudage nucléolaire TCOF1, qui recrute plusieurs protéines de réparation de l’ADN, y compris NBS1 et TOPBP1, vers les nucléoles, permettant une activation efficace des voies ATM et ATR pour …  Read more

Isac, Mihaiela (Supervisor2)  Read more

In this thesis, resource allocation problems relevant to multicarrier DSL environments are considered. The resources in a multicarrier DSL environment are bandwidth (i.e., subcarriers), the power allocated, the bits loaded and possibly the coding scheme used on each subcarrier. The major impairments in DSL environments are crosstalk and external noise . Crosstalk (predictable and controllable) is the interference caused by other DSL users sharing the same medium. External Noise (unpredictable and uncontrollable) consists of relatively high energy bursts due to electromagnetic interference from physical phenomena, electrical switches, motors and home appliances which are invariably present in the close vicinity of …  Read more

Les récents progrès en matière d’intelligence artificielle ont mis en évidence les atouts des grands modèles pré-entraînés dans diverses applications. Cependant, ces modèles ont souvent du mal à gérer les transformations des données d'entrée, ce qui est crucial pour les tâches exigeant l'invariance ou l'équivariance. Repenser chaque composant des architectures existantes pour atteindre l'équivariance est difficile et coûteux en termes de calcul. Nous étudions le cadre de canonisation pour la conception d'une architecture équivariante et proposons une nouvelle régularisation préalable pour aligner les entrées canoniques avec les orientations présentes dans les ensembles de données de pré-entraînement. Les résultats expérimentaux indiquent …  Read more

Two-dimensional convolution is one of the basic operations in image processing, where it is used as a filtering tool. A kernel of values corresponding to the spatial-domain impulse response of the filter is applied to the original image in order to perform desired operations such as low-pass filtering or edge enhancement. Since convolution is basically a two-dimensional multiply and accumulate operation, it is computationally intensive. General-purpose computer architectures are often ill-suited to perform two-dimensional convolutions, since they lack the required processing speed or memory bandwidth. This motivated the project to design and build a specialized device which can compute the …  Read more

The Lac Raudot complex is an Fe rich layered troctolite-anorthosite intrusion located in the Grenville province of southern Quebec. Corona textures developed between plagioclase and olivine indicate the Lac Raudot complex must have equilibrated at pressures of at least 6 to 8 kbar corresponding to depths greater than 15 km. The crystallization sequence of the layered series is olivine, followed by plagioclase and then ulvospinel. The mineralogy and chemistry of the layered series indicate differentiation by crystal fractionation along an Fe enrichment trend with olivine compositions varying from Fo 72 at the base of the layered series to Fo 57 …  Read more

La protéine von Hippel Lindau (pVHL) est un suppresseur de tumeur qui joue un role intégrale dans le développement de ccRCC. À date, plusieurs efforts ont été dirigés pour mieux comprendre ce role en tant que charactérizer sa function dans la dégradation de HIF et durant le processus de remodeler de la matrice extra-cellulaire (MEC). Le but de notre recherche était de charactérizer le méchanisme moléculaire par laquelle pVHL règle l'assemblée de la MEC. Pour attainder ce but, nous avons établis trois objectifs. Premièrement, nous avons voulu cerner si le role dont pVHL joue comme ubiquitine-ligase est indépendant de son …  Read more

Un nouvel appareil utilisant le principe de transfert de chaleur pour le séchage des céréales a été conçu et un prototype a été construit. Le sable est d'abord chauffe et ensuite mesure dans un espace cylindrique ferme avec une quantité prédéterminée de mais à haute teneur d'humidité. Les deux produits granuleux sont melanges pendant une période contrôlée et par la suite séparés. Les grains chauffes sont diriges dans un reservoir d'entreposage et l'intrant approprie (sable) est recirculé pour être chauffé à nouveau. Toutes les operations ont été pensées pour accomplir d'après les phases d'un procédé continu. Les résultats indiquent que …  Read more

La ville de Montréal a longtemps été un centre de changement et d'agitation politique et sociale au Canada. Abritant de nombreux courants migratoires au Canada, ces vagues de migrants ont exercé leur action politique à Montréal pour se tailler une forme d'autonomie et d'identité. Les Italo-Canadiens ont eu un impact unique sur le tissu sociopolitique de Montréal ; par contre, des événements tels que la Révolution Tranquille, la Crise d'octobre et le référendum québécois de 1980 ont divisé la diaspora quant au nationalisme québécois et à sa décision de s'y engager.Malgré leur perception monolithique par le grand public, la communauté …  Read more

Remarkably enough, there was no such thing as a problem of moral freedom for the ancients. More remarkably still, perhaps, there was no such thing for them as the concept of will, such as we know it today# Even though some explanation can be given of the reasons which prevented the problem from arising for the thinkers of antiquity, it nevertheless remains a most remarkable fact that it did not. Upon closer examination, this fact proves itself important as it is remarkable. For the concept of moral freedom serves as the basis for a thoroughly different approach to ethics, a …  Read more

English abstract The current study captured a deep understanding of physical education (PE) teacher perceptions about the inclusion of students with behavioural difficulties (BD). A mixed-methods research design was used to gain descriptive information about 11 PE teachers who participated in semi-structured interviews following completion of an attitudinal survey about inclusion in PE. Data analysis revealed five core themes: affordances & barriers, teacher-personal issues, teaching actions, future suggestions, and other. Findings demonstrated teachers' perceived constraints to inclusion, the complexity of BD, lack of adequate support, and inconsistent school communication. Many teachers suggested academic preparation about BD was inadequate. A majority …  Read more

En réponse à l'augmentation pré-ovulatoire de l'hormone lutéinisante (LH) , les cellules de la granulosa des follicules ovulatoires subissent la lutéinisation et forment le corps jaune (CL). Au cours de ce processus, les cellules de la granulosa acquièrent la capacité de synthétiser le progestérone, un processus qui nécessite beaucoup d'énergie. En effet, la LH est connu pour sont effet stimulant sur l'absorption du glucose dans l'ovaire lutéinisé chez le rat, mais les mécanismes n'ont pas été explorés. L'absorption du glucose par les cellules est médiée par une famille de transporteurs de glucose (GLUT) qui permettent le transport passif de glucose. …  Read more

Last year (1992) marked the 50th anniversary of wartime housing in Montreal. Built as temporary shelter for workers engaged in the war industry, these homes were to be demounted after the war. Public demand for inexpensive housing however, forced authorities to allow workers and veterans to purchase a unit. No bigger than a 1000 ft$ sp2$ (100 m$ sp2$), the wartime home can be investigated as a prototype for today's small affordable housing. Downsized homes, tailored to suit modern lifestyles and provide opportunity for ownership, have been criticized by theorists like Ruth Madigan, Moira Munro and Constance Perin for their …  Read more

A modified LoSurdo discharge tube has been designed suitable for investigation of Stark-effect in metals having high melting point. Stark-effect in iron has been observed in the region 6500 - 3400 A at field strengths in excess of 110,000 volts/cm. Two hundred and twenty one lines were photographed, twenty eight of which were found to be displaced. Stark-effect manifests itself by simple small displacements of the lines. Many lines reported by previous observers as being displaced in a field of about 30,000 volts/cm are shown to be undisplaced at any field up to 110,000 volts/cm and over. The relation between …  Read more

Adolescence is a dynamic developmental period of increased psychiatric vulnerability. Social stress in adolescence has detrimental effects on mental health, impacting boys and girls differently. Indeed, the prevalence rates of psychiatric disorders of adolescent onset is skewed between males and females. Understanding how exposure to social stress in adolescence interacts with the prominent dimorphic maturational changes occurring in the adolescent brain, is critical to develop prevention strategies to decrease the incidence of psychopathologies. In chapter I, I provide an overview on psychiatric susceptibility in adolescence and how it coincides with the protracted development of the prefrontal cortex (PFC) dopamine system. …  Read more

E-cigarettes are battery-powered devices that heat a liquid containing nicotine and flavouring agents to produce an aerosol that is inhaled by the user. Although initially marketed to cigarette smokers as safer alternatives to smoking, e-cigarettes today are predominantly used by youth, including children, adolescents, and young adults. Currently, there are thousands of different devices and flavoured e-liquids available on the market, but limited health information related to their use. This lack of basic safety information is hampered in part because there is no standard preclinical model to study e-cigarette toxicology. Because of this, there is conflicting evidence about the effects …  Read more

Ainsi voyons-nous comment saint-Vincent-de-Paul a influencé l'éloquence de son siècle. D'abord, par ses instructions, par ses avis, par son exemple surtout, et par les succès apostoliques obtenus, par le genre de prédication qu'il préconisait, il sut inspirer à tous les prêtres qui l'approchaient, l'amour de ce qu'il appelait modestement, sa "petite méthode". si, à cette influence directe et personnelle, on ajoute celle qu'il exerça indirectement, par les prêtres de sa "Compagnie des prêtres de la Mission" dits aujourd'hui Lazaristes, soit dans les missions, soit dans les séminaires, et aussi par les membres da la Conférence du mardi, formés par lui, …  Read more

Sediment cores in the North Atlantic show evidence of periodic large-scale ice discharge events between 60 kyr and 10 kyr before present. These so-called Heinrich Events (HEs) occurred with a typical period between 5 kyr and 10 kyr. During each HE, a significant amount of ice was discharged from the Laurentide ice sheet into the North Atlantic. This input of freshwater through the melting of icebergs is thought to have strongly reduced the strength of the Atlantic thermohaline circulation. One theory for HEs is that they are due to an internal oscillation of the ice sheet under constant forcing. This …  Read more

This doctoral thesis analyzes the plays of Tristan Tzara, specifically La Premiere Aventure Celeste de Monsieur Antipyrine (1920), La Deuxieme Aventure Celeste de Monsieur Antipyrine (1920), Coeur a Gaz (1921) et Mouchoir de Nuages (1924).  Read more

The purpose of this study was to address two specific issues related with the clinical application of Modulated Electron Radiation Therapy (MERT). The first was to investigate radiation-tolerant solutions for automated motion control of a Few Leaf Electron Collimator. Secondly, we implemented a fast, Monte Carlo-based, parameterized beam model for characterization of the electron beam in modulated deliveries.Two approaches were investigated for the implementation of a radiation-tolerant position feedback system: (i) the use of CMOS-based optical encoders protected by a prototype shield and (ii) the use of an analog device, such as a potentiometer, whose radiation tolerance is significantly higher. …  Read more

This PhD thesis pertains to the subject of small field dosimetry. Small photon fields, generally referring to fields smaller than 2 × 2 cm2, are routinely used in the clinic during modern radiotherapy treatment deliveries. However, several investigators have raised questions regarding the accuracy of the dosimetry in such conditions. An important issue involves the significant perturbations that are caused by most detectors in small field conditions. These perturbations will result in erroneous dose calculations during treatment planning and affect the treatment outcome. Currently it is still not clear which detector system should be preferred in small fields. In this …  Read more

During the last several years, there has been a dramatic growth of digital services, such as digital wireless and wireline communications, satellite communications and digital voice storage systems. Such services require the use of high-quality low bit-rate coders to efficiently code the speech signal before transmission or storage. The majority of such coders employ algorithms that are based on Code-Excited Linear Prediction (CELP). The goal of this thesis is to improve the quality of CELP coded speech, while keeping the basic coding format intact. The quality improvement is focused on voiced speech segments. A Pitch Pulse Averaging (PPA) algorithm has …  Read more

La traduction des ARNm en protéines est un processus important et finement régulé dans la biologie de la cellule. Dans les cellules de mammifères, la phosphorylation de la sous unité alpha du facteur d'initiation de la traduction 2 (eIF2alpha) est un mécanisme important du contrôle de la traduction. Cet événement est induit par une famille de kinases activées par différentes formes de stress cellulaire. Notre travail s'intéresse aux nouveaux rôles de la voie de phosphorylation d'eIF2alpha dans la régulation du facteur induit par l'hypoxie 1-alpha (HIF-1alpha), un facteur clef activé par des conditions hypoxiques dans le microenvironnement de la tumeur. …  Read more

Professional learning communities (PLCs) have become increasingly prevalent as a strategy for engaging teachers in school planning and distributing leadership function within schools in Quebec. While many scholars have praised the potential of PLCs, their effectiveness in practice has been called into question. This qualitative study offers a close examination of PLCs by exploring the experiences that teachers and pedagogical consultants have had in PLCs, and by outlining how these experiences have shaped their perceptions of PLCs. This research, consequently, seeks to contribute to the literature on professional learning communities through an exploration of PLCs within a particular context – …  Read more

St-Pierre, Julie (Supervisor1)  Read more

A field lysimeter experiment was conducted on a sandy loam soil during the 1990 and 1991 growing seasons. The experiment tested the effects of different watertables on soybean yields, and on moisture distribution and nitrogen concentration of the soil profile. The watertable depths were 40, 60, 80, and 100 centimeters (cm). Yields were measured in terms of number of beans per plant, number of pods per plant, number of beans per pod, and seed protein content at harvest. Soil samples collected at depths of 30 and 70 cm from the soil surface were analyzed for moisture content and NO$ sb3 …  Read more

Robots with four legs offer a good tradeoff between stability, load carrying capacity, and mechanical complexity when compared to bipeds and hexapods. In order to achieve the best mobility, speed, and energy efficiency, dynamic walking and running operation is preferable to static gaits. This requires leg compliance to reduce impact forces and energy consumption. At the Ambulatory Robotics Laboratory, (ARL), we have pursued an agenda of low mechanical complexity in our Scout I and II robots, in order to decrease cost and increase reliability. Research previously undertaken at the ARL group has accomplished walking and stair climbing with Scout I …  Read more

Dans cette thèse, nous étudions le problème d'estimation des canaux en cas de défaillances matérielles sur les grands systèmes MIMO. Les grands systèmes MIMO sont équipés de dizaines à centaines d'antennes sur la station de base, offrant de nombreux avantages par rapport aux systèmes MIMO traditionnels, tels que de meilleures performances et une efficacité énergétique accrue. Les grands systèmes MIMO sont souvent fabriqués à partir de composants à faible coût, ce qui peut conduire à des imperfections matérielles et se solder par du bruit de distorsion au niveau de la station de base et des utilisateurs. Afin d'élaborer un modèle …  Read more

The function of the normal cellular human prion protein (PrPC), a highly expressed protein of the brain, is presently unclear. Based on the amino acid sequence homology between PrPC, Bcl-2, and Bax proteins, we propose that PrPC may be implicated in modulating neuronal survival and death as a member of the Bcl-2 family of proteins. The present study investigates interactions between human PrPC, Bcl-2, and Bax in human primary foetal neurons as well as in, human foetal and adult brains by crosslinking and co-immunoprecipitation. The PrPC-Bcl-2 interaction was also tested by the yeast-two-hybrid system. Results indicate an interaction between PrPC …  Read more

Elevated brain levels of amyloid-β (Aβ) and transforming growth factor- β1 (TGF-β1) are thought to contribute to the cognitive and cerebrovascular alterations of Alzheimer's disease (AD). Here, we sought to investigate the role of simultaneous increases of Aβ and TGF-β1 on cerebrovascular, neuronal, glial and mnemonic function using a bitransgenic mouse model concurrently overexpressing a mutated form of the human amyloid precursor protein (APPSwe,Ind) and a constitutively active form of TGF-β1 (A/T mice). In addition, we attempted to counter these deficits using three different pharmacological agents: the peroxisome proliferator-activated receptor (PPARγ) agonist pioglitazone (20mg/kg/day), the 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitor simvastatin (40mg/kg/day) …  Read more

Urotensin-II (U-II) and its receptor UT are upregulated in the pathological setting of various cardiovascular diseases including atherosclerosis. However, their exact role in atherosclerosis remains to be determined. In the present study, we hypothesized that selective overexpression of UT in an SMC-specific fashion would increase atherosclerotic lesion formation in a hypercholesterolemic mouse model. The objectives were to demonstrate the role of UT in this mouse model of atherosclerosis, and to elucidate some of the mechanism involved in the process. We used four strains of mice; wildtype (WT), UT+ (a transgenic strain expressing human UT driven by the alpha-SM22 promoter), ApoE …  Read more

The perturbative regime of Quantum Chromodynamics (QCD) is considered and certain aspects related with higher order corrections (HOC) are studied. Certain large correction terms in the perturbative expansion are determined, in particular for large transverse momentum $(p sb{T})$ direct photon production. The origin of these terms is specified and simple forms, called K-factors, are provided (soft gluon approach). Furthermore, for processes initiated by 2 $ to$ 2 particle subprocesses the structure of the complete HOC is analyzed. It is shown that when structure functions and/or fragmentation functions are involved, there is a gauge invariant part that dominates HOC over a …  Read more

The purpose of this research is to investigate the emotions of pre-school children. The research task was to elicit children's affective responses to music through the act of drawing. Three pre-school children with no formal musical training or formal schooling participated in the study. During three sessions of "play" they played musical instruments, listened to music selected for sharp contrasts in mood, and drew pictures. The children expressed their feelings about the musical selections by drawing on large sheets of paper with coloured pencils. Afterwards they discussed how they felt about the music and they described how their drawings related …  Read more

The De miseria humane conditionis (1191--1195) by Lotario di Segni (Pope Innocent III) was a greatly influential text in medieval culture, and was translated and reworked in many European languages. Early translations of the work, however, have been usually overlooked by scholars. This is true in particular of Della miseria dell'uomo, composed in the second half of the 13th century by the Florentine judge Bono Giamboni. My thesis consists in an extensive comparison of Bono's Della miseria dell'uomo with Lotario's De miseria humane conditionis. My purpose is twofold: to detect the differences between the two texts; and to understand how …  Read more

Sarkar, Mekhala (Internal/Cosupervisor2)  Read more

In this study a model of collective bargaining is proposed in which collective bargaining is considered as an ongoing process with component activities recurring periodically. The eight component activities identified are: (1) influential variables, (2) perception and evaluation of the influential variables, (3) bargaining power, (4) prediction, (5) negotiation, (6) mechanism of dispute settlement, (7) feedback loops, and (8) the collective agreement. In addition to the model, an evolution of collective bargaining by teachers in the CEGEP sector of Quebec is presented. This is achieved by descriptive case studies of the first four rounds (1967-1980) of collective bargaining in this …  Read more

The effect of fatty acids on energy metabolism has been shown to be dependent on their acyl structure. In humans, following short term feeding, medium chain triglycerides (MCT) have been shown to increase the thermic effect of food and fat oxidation as compared to long chain triglycerides (LCT). Short term results in animals have been comparable. In longer term, animal studies, MCT vs. LCT have resulted in less weight gain during overfeeding or refeeding after weight loss. However, observations of the longer term effects of MCT in humans beyond 7 days are sparse and inconclusive. Hence, the objective of the …  Read more

Ouellet, Jean Albert (Supervisor2)  Read more