McGill University Thèses et mémoires par auteur commençant par A

Memory is one of the cognitive functions that is most affected in schizophrenia and memory dysfunctions have a major impact on the functioning and quality of life of these patients. Functional brain imaging can help us identify the brain structures that are affected during the performance of a memory task. Identifying these regions can help us identify the specific cognitive processes that are affected in schizophrenia. [...] The identification of selectively intact and deficient processes involved in memory encoding has potential clinical relevance for the development of more focused cognitive remediation strategies.  Read more

The control of nonholonomic systems is a challenging theoretical problem that has numerous engineering applications. One such interesting application is the control of wheeled mobile robots. This thesis presents four approaches that can be used to control these nonholonomic systems. The first three approaches are used to stabilize a robot mounted on a two-wheeled cart, while the fourth one stabilized a robot mounted on a four-wheeled cart. Feedback linearization can stabilize or track the position but not the orientation of the cart, so practical stabilization can be achieved by tracking a continuously moving reference cart. A geometric approach can stabilize …  Read more

Mise en contexte : Parmi le peu de stratégies de prévention de la prééclampsie (PE), une des causes de mortalité maternelle et infantile, un champ d'étude récent implique son association avec la la vitamine D. L'indicateur biologique clé pour la détermination du statut en vitamine D est la 25-hydroxyvitamine D (25(OH)D). Toutefois, la valeur seuil de réduction du risque de PE n'a pas encore obtenu de consensus. Objectifs: 1) Quantifier la relation entre les concentrations sériques de 25(OH)D en début de grossesse et le diagnostic ultérieur de PE; 2) Déterminer s'il existe une relation dose-effet entre les niveaux sériques de …  Read more

Normal development of the placenta is crucial for embryonic survival and growth. Tmed2 is a gene, which has been found to be necessary for the formation of the labyrinth layer of the placenta, as well as for embryonic development. The objectives of this thesis are to: describe the transcripts of Tmed2 using Northern Blot analysis; elucidate the expression pattern of Tmed2 in the developing embryo and placenta using whole mount and section in situ hybridization; determine whether homozygous mutant embryos (Tmed299J/99J) are undergoing ER stress using RT-PCR. Tmed2 has three transcripts; however, only one of these transcripts contains exon 1 …  Read more

The purpose of this study was to examine the role of the secondary school principal in anglophone Quebec. A sample of eighteen experienced principals were interviewed in-depth about their role expectations, sources of role conflict, and their sense of ambiguity. Role ambiguity appeared to be non-existent in the principalship. Expectations and conflicts were identified with regard to students, teachers, parents, community members, and principal's superiors. The principalship was clearly more a managerial than leadership role. Principals were responders to a series of problems and issues. They orchestrated responses. Instructional leadership was not a part of their role.  Read more

In the early stages of visual processing (primary visual cortex) shapes are sampled by discrete, localized, visual filters. The integration of the outputs of these local filters allows us to detect global shape information. Although this integration process is critical for visual processing beyond the primary visual cortex, it remains poorly understood. This thesis investigates what limits the performance of the mechanisms used to detect global structure. In particular, we asked four questions: (1) What information is important for detecting global form? (2) How well can we detect shape defined by changes in contrast? (3) Do the spatial properties of …  Read more

Simpson, Benjamin K. (Supervisor1)  Read more

Stearn, Colin W. (Supervisor)  Read more

Chapman, Lauren (Supervisor1)  Read more

In spite of a broad body of theoretical discussion on generativity, empirical research has yet to confirm many central tenets of the theory. Within 2 research studies, 3 questions were addressed. A study of 98 midlife men and women pursued (1) the relationship between generative concerns and 4 indicators of adjustment, positive affect, negative affect, life satisfaction, and work satisfaction, and (2) the role of agency and communion as predictors of generative concerns, with attention to sex differences in these predictive roles. A study of 75 largely pre-midlife women and men provided a conceptual replication of the results of the …  Read more

La fibrose kystique (FK) est une maladie mortelle causée par des mutations dans le gène cystic fibrosis transmembrane conductance regulator (CFTR). La protéine CFTR, exprimée dans plusieurs cellules épithéliales et immunitaires, joue un rôle critique dans le maintien de l'homéostasie ionique et des liquides aux membranes cellulaires auxquelles se localise la protéine. Alors que la maladie touche surtout l'appareil respiratoire, les organes de la voie digestive sont aussi affectés. En revanche, les souris modèles de la maladie de FK ne démontrent que très peu de pathologies respiratoires, tout en possédant un important phénotype intestinal caractérisé par l'obstruction, l'inflammation et l'excroissance …  Read more

The core of this research project revolves around the development of knowledge and expertise in the field of sequence homology identification techniques, as applied towards the discovery of Bcl2 family members. The use of such methods resulted in the uncovering of a Bcl2 Homology 3 (BH3) domain in a ubiquitin ligase enzyme known as upstream regulatory binding protein 1 (UreB1). A complete biochemical analysis unequivocally demonstrated binding of the UreB1 BH3 domain to MCL-1, an antiapoptotic member of the Bcl2 protein family. Furthermore, the discovery of a BH3 domain in UreB1 may provide a link in the established involvement of …  Read more

Les méthodes the modélisation sont devenues un outil inestimable dans le processus de découverte et de développement de nouveaux médicaments. Au cours de cette thèse va être décrit le développement et l'application de méthodes utilisés à chaque stage de la découverte et du développement de produits pharmaceutiques. Le Chapitre 2 est un aperçu sur l'utilisation de méthodes computationnelles vers le développement de deux nouveaux inhibiteurs des protéines Bcl-2, Obatoclax et ABT-737, en développement pour le traitement du Cancer. L'étude propose certains mécanismes d'ABT-737 qui expliquent ca sélectivité envers les membres de la famille Bcl-2. De plus, nous proposons un mécanisme …  Read more

Cette thèse explore comment les technologies numériques modernes peuvent être exploitées pour enrichir la pédagogie de la pratique instrumentale, avec un accent particulier sur l’enseignement de la trompette. En commençant par un examen approfondi des outils éducatifs et des logiciels existants, cette recherche identifie un potentiel inexploité des technologies numériques afin de fournir un retour en temps réel sur la performance musicale et soutenir un apprentissage autonome de l’élève.Afin d’exploiter ce potentiel, nous avons utilisé un environnement modulaire et open-source dedié à la création d’applications éducatives, et permettant le développement de solutions sur navigateur et mobiles hybrides grâce à des …  Read more

The effects of taurine deficiency on aspects of retinal cGMP metabolism were examined. Rats were made taurine deficient by the administration of 1% GES. The activities of the key enzymes of cGMP metabolism, phosphodiesterase and guanylate cyclase, were indirectly determined by the response of retinas to light and to low calcium. Dark-adapted retinas of rats treated with GES for 4 and 8 weeks exhibited significantly smaller decreases in cGMP in response to light exposure as compared to control retinas. Retinas from 4 and 8 week GES-treated rats also exhibited smaller increases in cGMP when they were exposed to 0.1nM calcium. …  Read more

A technique was developed to study the effect of surfactant (frother) on individual bubble motion in swarms. The technique was based on high speed cinematography and tracking of multiple moving objects. Image processing algorithms were implemented in Matlab to isolate and measure geometric properties of the bubbles in image sequences recorded at 1 ms interval; and these properties were compiled into a data structure. To track a bubble, the geometric properties and a matching criterion were applied on consecutive pictures to identify the bubble. The bubble trajectory was reconstructed from the data structure for the matched objects. To maximize the …  Read more

The important and exemplary role that Internet technology played in enhancing the publicity campaign of the Chiapas insurgents in their struggle for political reform in Mexico, is the focus of this thesis. By examining the Internet as an alternative distribution network for Subcomandante Marcos' communiques, it can be conjectured that the technology provided him with a space through which his voice could be heard in the international political arena. It was a space both external to Mexican government control, and through which Macros disseminated a powerful discourse representing the insurgents' political goals and grievances--one contrary to that being transmitted by …  Read more

Le droit coutumier et les institutions traditionnelles constituaient auparavant l'ensemble du système judiciaire Camerounais. Ce système régulait un vaste champ d'activités au Cameroun. Pourtant, ce système de droit qui existe dorénavant dans le contexte du pluralisme légal est confronté à plusieurs défis, vu que le système judiciaire Camerounais peine à trouver un équilibre approprié dans la mise en pratique des différents ordres légaux coexistant. Plusieurs facteurs peuvent expliquer les raisons d'une régression du droit coutumier en tant qu'institution. Ceci est certainement le cas du Cameroun dont l'histoire coloniale démontre une absence de l'indigène dans la création et l'évolution des appareils …  Read more

Therien, Denis (Supervisor1)  Read more

The notion of communication complexity was introduced by Yao in his seminal paper [Yao79]. In [BFS86], Babai Frankl and Simon developed a rich structure of communication complexity classes to understand the relationships between various models of communication complexity. This made it apparent that communication complexity was a self-contained mini-world within complexity theory. In this thesis, we study the place of regular languages within this mini-world. In particular, we are interested in the non-deterministic communication complexity of regular languages. We show that a regular language has either O(1) or O(log n) non-deterministic complexity. We obtain several linear lower bound results which …  Read more

The stomach has the unique ability of being able to contain an acid solution as distinct from the property of the parietal cell mass to secrete acid. Using a method of measuring in situ volume and ionic changes within innervated and denervated gastric pouches developed by Wlodek and Leach, this function of the stomach was studied using various stimuli. Feeding in Heidenhain pouches produced an increased competency of the gastric mucosal barrier as measured by the decreased exchange of hydrogen for sodium ions. Antrectomy did not reduce this effect significantly indicating that intestinal or pancreatic factors may be important in …  Read more

This thesis contains an account of the nature and uses of sponge iron, the conditions theoretica1ly necessary for its production and methods that have been proposed for its production. It also describes experiments made by the writer to obtain information regarding the conditions essential for the production of sponge iron by heating hematite and magnetite ore with charcoal, peat, lignite, bituminous coal, coke and anthracite. There was no attempt made to devise or test any process tor the commercial production of sponge iron. The purpose of the work was to obtain information which would be fundamental for the design of …  Read more

In this thesis, we will discuss an extension of the classical Galton-Watson process called Branching Process in Random Environments. The first chapter will be concerned with necessary and sufficient conditions for certain and noncertain extinction of the process and we will see that just as the mean number of offspring per individual was important in determining whether the classical Galton-Watson process had certain or noncertain extinction, it is now E log m(~ 0 ) which will play the role of criticality parameter. […]  Read more

We questioned whether adrenergic amines extracted from the Seville orange Citrus Aurantium (CA) increases metabolic rate and enhance the thermic response to a 1.7MJ mixed meal (TEF) in lean and obese men and women; the latter had upper-body obesity, a condition associated with defective TEF, attributed to altered SNS. Nine lean (7M, 2F; BMI: 23 +/- 1 k g/m 2; waist circumference: 78 +/- 2 cm) and 13 obese (4M, 9F; BMI: 35 +/- 1 kg/m2; waist circumference: 105 +/- 3 cm) subjects were studied. With CA: (1) RMR increased more in men vs women (94 vs 42 kJ over …  Read more

This thesis is composed of two parts, one a translation, the other a commentary on the material that has been translated---a set of three well known identically entitled works by the famous Indian Buddhist scholar, Kamalasila (c. 740--795 C.E.). The Bhavanakramas are here translated from both Sanskrit and Tibetan sources. The commentary takes the form of an extended critical Prologue to the texts and is centred around an examination of the notions of meditation and insight as found therein. The first chapter of the commentary examines the various terms for meditation found in the texts and argues for a specific …  Read more

The transferrin receptor is a membrane protein which is involved in the binding and endocytosis of transferrin, the main Fe$ sp{3+}$ carrying protein. The receptor and transferrin function to provide cells with iron, an essential nutrient. As red cells mature and lose their ability to make hemoglobin, they also lose their capacity to bind transferrin and take up iron. The transferrin receptor in sheep reticulocytes has been shown to undergo externalization in vesicular form during maturation of sheep reticulocytes in vitro. Microscopic studies show that the receptor is internalized into endosomes and externalization, in vesicular form, occurs via formation of …  Read more

$ beta$-Hexosaminidase (Hex) is an essential lysosomal enzyme whose absence in man results in a group of disorders, the G$ sb{ rm M2}$ gangliosidoses which includes Tay-Sachs and Sandhoff diseases. There are two major isoenzymes of Hex, Hex A ($ alpha beta$) and Hex B ($ beta beta$). Two cell types, apical and narrow cells, in the initial segment of the rat epididymis immunolocalized Hex. Principal cells of the epididymis were intensely reactive for Hex only in the intermediate zone, caput and proximal corpus regions. Clear cells were reactive in the regions of the epididymis where they were found. Electron …  Read more

Balbuzard is a musical composition of approximately twelve minutes in length, scored for solo clarinet, wind symphony and electronics. It focuses on cluster-like sound masses and explores ways of using these to give the music a clear sense of direction. To this end, tools were developed using a variety of computer applications or programming languages, such as Lisp, OpenMusic and Cubase. These tools made possible a kind of graphic composition where diagrams of different shapes were entered into a computer interface and converted into source material. The generated source material consisted of several rhythmic strata whose pitches, mainly part of …  Read more

Ferguson, Sean Alastair (Supervisor2)  Read more

Les études récentes d’imagerie cérébrale humaine ont tendance à augmenter les résolutions d’acquisition d’images par résonance magnétique (IRM), cherchant des niveaux de détails plus fins et une morphométrie cérébrale plus précise pour mieux étudier le développement, le vieillissement et les maladies du cerveau. Cependant, les images à plus haute résolution contiennent intrinsèquement plus de bruit, ce qui entraîne une morphométrie cérébrale de moins bonne qualité si ce niveau de bruit n’est pas pris en compte adéquatement. Au lieu d’acquérir un grand nombre d’acquisitions afin d’augmenter la qualité de l’IRM par moyennage -ce qui est long et coûteux- des méthodes de …  Read more

Le travail présenté analyse l'influence des conditions météorologiques sur la demande de cyclisme urbain en suivant deux objectifs : 1) étudier l'impact des conditions météorologiques et de la demande de vélos à l'aide de modèles de séries temporelles et 2) effectuer une analyse climatique pour estimer la demande de vélos en 2050 selon différentes projections de modèles climatiques. Pour le premier objectif, la méthodologie proposée a caractérisé la dynamique temporelle des profils de fréquentation quotidiens et hebdomadaires, identifié les tendances des modèles utilitaires et déterminé les tendances de la fréquentation d'une année sur l'autre tout en contrôlant l'influence des variations …  Read more

Melzack, R. (Supervisor)  Read more

Starch xanthates were first prepared over 50 years ago, and since then little has been learned about their chemical structure; even suggestions for their industrial utilization have been very few. In the meantime, the emergence of the viscose process and the rayon and cellulose film industries has stimulated a great amount of research on cellulose xanthates all over the world but, nevertheless, little knowledge has been gained about the distribution of the xanthate groups in the cellulose macro-molecule, and particularly within the anhydroglucose units. Only recently, attempts were made in these laboratories to locate the xanthate groups in samples of …  Read more

In general, metal deposition is the process by which ions are electrolytically reduced and deposited in the solid state on an electrode. For example, when a direct current is passed through a copper sulphate solution between two copper electrodes, copper dissolves from the anode and deposits upon the cathode. The flow of current is accompanied by the development of cathodic and anodic polarization, which represent increases in potential above the single electrode or equilibrium value for the metal in contact with the same solution in the absence of current flow.  Read more

Most people place their sincerest hopes for emotional fulfillment on a rewarding family life. The "loved ones" that constitute our nuclear and extended familial worlds are the primary beneficiaries of our affections and of the fruits of our labors. In return for the primacy we accord our family members, we expect their behavior to demonstrate their loyalty to the clan. However, at a certain point obligations to the family can conflict with the needs of the individual. In this thesis I examine how filial duties influence the plights of the tragic heroines in Sophocles's Antigone and Shakespeare's King Lear. Both …  Read more

Sexual 'arousal' in Helix aspersa can be divided into 2 components, sexual proclivity (the tendency of a snail to respond to conspecific contact with courtship) and sexual arousal (the intensity with which the snail courts). Sexual proclivity and sexual arousal have different effects on feeding and locomotion and are differentially affected by sexual isolation, daily conspecific contact, and by a courtship pheromone found in the digitiform gland mucus. Therefore sexual arousal and sexual proclivity are probably mediated by 2 separate physiological mechanisms. Behavioural state, or the animal's general level of activity, correlates positively with mating behaviour. However, although a central …  Read more

This study is an inquiry into the impact of a mentally retarded child upon the family unit. The research group interviewed forty-four families with a mentally retarded child, known to the Mental Assessment and Guidance Clinic of the Montreal Children's Hospital. The areas of investigation include the roles of mothers, fathers and siblings of a mentally retarded child, the stresses experienced in fulfilling these roles, and the adaptations made to the existing stresses. [...]  Read more

Viennese Expressionism 1909-1913 encompasses parallel evolutions in the disciplines of visual arts and music. Ideas from fin-de-siecle Vienna's intellectual milieu inspired the awakening of the Modern artist, from Ur-schrei to the formation of a new aesthetic theory. In this thesis, I examine the origin of iconic Expressionist aesthetic values and their technical expression in works by Arnold Schoenberg, Egon Schiele, Oskar Kokoschka, and Wassily Kandinsky. Topics covered are divided into two broad thematic categories whose central tenets originate in preoccupations with, on the one hand, an emerging understanding of the unconscious and psychic pathology; and on the other hand, the …  Read more