McGill University Thèses et mémoires par auteur commençant par W

This thesis aims at providing stakeholders with an improved transparency of machine learning models by investigating various augmentations to model predictions, both throughout the model life cycle and across different inspection scales.We begin by examining the process of selecting a bandit policy from logged data in environments with large action spaces. We focus on identifying conditions on action vector representations that enable accurate estimation of the value of a policy without live deployment. This allows us to efficiently provide accuracy information to the policy designer and facilitates offline policy selection.We then move from the model design level to focus on …  Lire la suite

Aujourd'hui, la qualité des ovocytes maturés in vitro n'est toujours pas satisfaisante. En effet, seulement 5 à 10% des ovocytes peuvent intrinsèquement engendrer in vitro des embryons avec entière compétence développementale. Récemment, des études ont montré l'importance qu'a l'épigénome, mécanisme qui active ou inhibe l'expression des gènes, dans le développement embryonnaire. Effectivement, plusieurs protéines reconnues capables de modifier les histones telles que l'histone déacétylase 1 (HDAC-1), la déméthylase spécifique aux lysines 1 (LSD-1), ainsi que le gène brahma related 1 (BRG-1), ont été démontrées vitales aux premiers stades développementaux. Nos expériences ont pour buts de décrire par immuno-détection la présence …  Lire la suite

À l'époque de la globalisation de l'enseignement supérieur, on fait appel à des projets de recherche qui étudieraient les expériences de transition interculturelle vécues par des étudiants internationaux et leur besoin de services en orientation professionnelle. Si l'on sait beaucoup sur l'adaptation initiale au pays hôte, on est moins bien informé sur la transition que vivent ceux qui regagnent leur pays d'origine. Les études disponibles avancent l'idée que les étudiantes internationales font face à plus de difficultés que les étudiants internationaux au moment de rentrer chez eux. Or, il est rarement question des contextes d'ordre social ou concernant le sexe …  Lire la suite

The objectives of this study were (1) to examine the nature and extent of cultural diversity in Japan; (2) to ascertain the meaning of multicultural education in both the North American and Japanese contexts; and (3) to make judgements concerning the relevance of multicultural education to Japanese education. It was determined that Japanese society is indeed a culturally diverse one, that the cultural minorities are relatively small in numbers and that the Japanese government has traditionally followed a policy of the cultural assimilation of minorities. Using conceptual analysis to investigate the meanings of multicultural education, the study found that the …  Lire la suite

La littérature académique abonde d'écrits portant sur les objets du racisme, ainsi que sur ses effets en tant que système de domination pour les populations racisées. Par contre, on retrouve peu de textes qui traitent des populations qui maintiennent le racisme et qui en profitent. Au Québec, les écrits sur la « blancheur » sont très rares en anglais et inexistants en français. Historiquement, la blancheur a été construite comme étant supérieure à travers un processus de racialisation, où l'autre racisé était exclu de toute humanité. Cette exclusion était justificative de l'exploitation de son labeur, de ses ressources et de …  Lire la suite

Of all the major vegetational regions recognized on the earth's surface the tropical grasslands are those which most defy definition and on which least agreement has been reached concerning their origin and present environmental controls. The literature on the subject is already extensive, these grasslands having attracted the attention of a large number of natural scientists, in particular botanists, geographers and zoologists, yet almost all this work suffers from 'inadequate field data, and an almost total lack of experimental evidence’. {J. S. Beard, 1953; p. 149.) In consequence, interpretations tend to be highly coloured by, one, the nature of the …  Lire la suite

Cette thèse explore les effets involontaires de la subdivision des terres dans un environnement de pâturages semi-arides dans le comté de Laikipia, Kenya. Il est argumenté que les rapports de propriété où plusieurs types de propriétés existent côte à côte sont complexes, en particulier lorsque les utilisateurs des terres adjacentes produisent selon des stratégies différentes (par exemple, la production d'élevage mobile vs limites fixes de ranchs privés). Selon cette étude, la propriété privée telle que pratiquer par les pasteurs à Laikipia, représentée par les zones subdivisées occupées et utilisées, ne se conforme pas aux hypothèses largement répandues de la théorie …  Lire la suite

Studies were conducted to determine the effect of phenelzine on the pharmacology and metabolism of ethanol. Pretreatment for one half hour with phenelzine (40 mg./kg. i.p.) prolonged the mean ethanol sleeping time in mice by more than 350%, but, unexpectedly, decreased the toxicity of ethanol, as reflected in a change of LD 50 from a control value of 4.14g./kg. to 5.16 g./kg. A partial explanation of these results was thought to reside in the effect of phenelzine on the rate of ethanol degradation. Determinations of ethanol concentrations in whole mice over a 4 hour period indicated that phenelzine caused a …  Lire la suite

L'utilisation, par des individus sains, de médicaments pour améliorer leurs fonctions cognitives suscite l'attention autant des bioéthiciens que des médias. L'importante couverture médiatique de ce récent phénomène soulève la préoccupation qu'une fausse représentation des données scientifiques, relativement à la sécurité et à l'efficacité de ces médicaments, pourrait, par conséquent, éveiller l'intérêt du public. Potentiellement, cela pourrait causer des effets négatifs au plan social, par exemple, en encourageant la conformité et donc une perte de la diversité.Un médicament en particulier, le donépézil, s'est vu reconnu comme étant un « produit d'amélioration des fonctions cognitives ». Cette affirmation est basée essentiellement sur …  Lire la suite

Best, E. (Supervisor)  Lire la suite

Previous research has concluded that individuals develop relatively invariant problem solving 'styles' which cause them to be more comfortable and effective in certain task environments. This study of management consultants, employing a self descriptive questionnaire, found that fifteen measured attributes clustered onto three factors: a line/staff orientation, a grounded/ungrounded approach to problem conceptualization, and a rational/instinctive approach to conclusion drawing. Attributes were analyzed by functional area, consulting firm, task effectiveness, potential to become a partner, etc. Task performance ratings and personality assessments were provided by supervisors. It was found that many of the attributes studied did not correlate with task …  Lire la suite

This thesis investigates the phenomenon of for-to complements in several dialects, focusing primarily on Appalachian English, though Belfast English and Ottawa Valley English are also examined. Following Chomsky's Government and Binding theory, we develop an analysis of for-to that predicts the distribution of for-to complements based on the requirements of Case, and the varieties of licit movement of features allowed by each dialect. To do this, we propose a Revised Case Filter which requires functional categories bearing Case features to discharge Case. We also show that the features of functional categories can move either by head movement (allowing movement of …  Lire la suite

Mason, S. (Supervisor)  Lire la suite

Progress, in the design of machinery and in the knowledge of operating conditions, is made as a result of research in which various factors are balanced against each other and the less efficient discarded. Such experimental work is much simplified if there exists some accurate method by which true efficiency can be measured. Conversely, if this efficiency cannot be measured then the work is much more difficult and some relative method of comparison must be resorted to. Only too often this results in disagreement as to a suitable usable unit and confusion in interpreting experimental data obtained. [...]  Lire la suite

Experimental characterisation of rubber in uniaxial, equi-biaxial and planar tension under cyclic quasi-static loading shows strain-induced stress softening, hysteresis and unrecoverable strain. The objective of this work is to study the applications and limitations involved in predicting the behaviour of rubber with hyperelastic models. To assume a preconditioned perfectly elastic material, the data obtained from experiments must first be simplified. The data is then fitted to popular hyperelastic models in the finite element analysis (FEA) software ANSYS(TM). A single hyperelastic model (with given coefficients) is shown to only provide a good fit to a single characterisation test and level of …  Lire la suite

Security and privacy of photos stored in the clear in third party servers has been the biggest concern for customers in recent years. One way of enhancing the privacy and security of photos stored in third party servers is to encrypt the photos before storing them. However, using encryption to secure the information held in the photos precludes applying any image processing operations while they are held in the third party servers. To address this issue, we have designed and implemented a distributed image storage system that is based on the Chord protocol which enhances privacy using chaotic map transformations …  Lire la suite

In recent years there has been a notable increase in the number of suicides amongst South Asian youth in the Region of Peel in Ontario. Using a six-page questionnaire, an exploratory descriptive study was conducted with 104 participants. The purpose of the study was to inquire into the number of South Asian youth that had ever considered committing suicide; determine whether there were any predicting factors; and gain insight as to "why." It was found that close to 30% of the sample had considered suicide and that gender, place of birth and a self-rating scale of depression were significant variables. …  Lire la suite

Introduction. Numerous studies have suggested that maternal care can influence the development and expansion of an individual's self-esteem. Yet the neural mechanisms of this relationship remain unexplored. Incidentally, it has already been demonstrated that a brain region, namely the Hippocampus (HC) is associated with both self-esteem and maternal care. Thus suggesting that there may be a three-way relationship. This also provided the impetus to speculate that a similar interaction could be observed in other brain regions like for example, the Dorsolateral Prefrontal cortex (DLPFC) and the Medial Prefrontal Cortex (MPFC). Therefore, the aim of this study is to scrutinize the …  Lire la suite

Les grandes éruptions siliciques formant une caldeira sont peu fréquentes, mais leur impact sur l’humanité et son environnement peut être dramatique. Cela souligne l'importance d'une bonne compréhension de ces systèmes dits “supervolcaniques” et des processus qui se déroule dans les chambres magmatiques sous-jacentes. Valles caldera est un système idéal pour étudier ces processus: sa séquence continue d'éruptions fournit une fenêtre à la fois sur la chambre magmatique prête pour l’éruption, et sur le rétablissement de la chambre magmatique entre deux superéruptions.Les volatiles jouent un rôle clé dans les chambres magmatiques, aussi bien en tant qu'espèces gazeuses dissoutes dans le magma …  Lire la suite

In the field of education, the Islamic educational institutions, both formal and non-formal, have played a major role in educating Indonesians from the colonial era 1600-1945, to the present day. One of the Islamic educational institutions famous for its Islamic approach is the pesantren. This institution, however, is facing major challenges at present and is being asked to update, develop and change many of its programs in order to enable its graduates to participate more fully in Indonesian national life, particularly in the field of national development. As a result, some pesantrens began modernizing their educational systems. The modernization process …  Lire la suite

Potato proteins were isolated from industrial by-products potato fruit juice (PFJ) and potato pulp, using several conventional extraction techniques. Of the conventional methods assessed ammonium sulphate precipitation resulted in the highest protein recovery yield, with isolates enriched in non-denatured patatin, as demonstrated by best preservation of its lipid acyl hydrolase (LAH) activity. The novel enzymatic approach began with the use of pure enzymes, for the opening of the pectin network and the isolation of potato proteins. The protein recovery yield and recovered patatin was found to be antagonistically affected by temperature and units of endo-polygalacturonase, whereas the recovered protease inhibitors …  Lire la suite

Phillips, J. (Supervisor)  Lire la suite

The work of John Dee (1527-1608) posits an approach to architecture based upon the concept of wonder. Sympathetic correspondences permeate Dee's disparate practical activities and architectural discourse. His contributions to astronomy, alchemy, cartography and navigation are grounded in the intersubjective cosmology of the Renaissance. It is in Dee's Mathematicall Praeface (1570), which promotes mathematics as a natural philosophy, that the architect's metier is aligned with the marvellous and established as an art encompassing numerous disciplines. Dee's syncretic formulation of architecture is distinctly attuned to the alchemical and magical discourses pervading the Renaissance and established in relation to his hieroglyphic "Monas" …  Lire la suite

Using a theoretical model incorporating recent work in the field of historical epistemology and Michel Foucault's concept of governmentality this dissertation reconsiders key moments in the history of Canadian audiovisual policy as sites for examining the production of knowledge about national cultural activity. Drawing upon archival records, interdisciplinary research and a discursive analysis of policy documents, I argue that the resolution of questions regarding the nature of cultural expertise and the evidentiary value of different forms of knowledge accompanied changing state rationale towards film and broadcasting and foreshadowed the refashioning of Canada's audiovisual sector. To illustrate, I focus on a …  Lire la suite

Pastinen, Tomi Markku (Supervisor2)  Lire la suite

This study describes the resource management practices of a rural community located in Morobe Province, Papua New Guinea. Lababia, a community of 500 people, is located in a coastal rainforest environment and is dependant for its livelihood on swidden agriculture and fishing. Lababia is also the site of an integrated conservation and development project facilitated by a non-governmental organisation based in a nearby urban centre. The key resources on which Lababia depends are managed as the common property of either the village-as-a-whole or the various kin groups resident in the village, and for that reason common property theory has been …  Lire la suite

A partially purified preparation of in vivo activated human heat shock transcription factor (HSF) has been obtained from HeLa cells and its interaction with the heat shock response element (HSE) in the human Hsp70 gene promoter was investigated. A variety of DNA-protein binding studies including DNAse I protection, hydroxyl radical protection, and diethylpyrocarbonate interference analysis were used to investigate recognition of the HSE by human HSF. Direct contacts to bases within the 5 basepair recognition motif were detected and the overall pattern of binding was compared with the Drosophila results. Analysis of the high resolution protection patterns to extended HSE …  Lire la suite

La maladie de Parkinson est parmi les maladies neurodégénératives les plus répandues. Elle se caractérise par la perte des neurones dopaminergique dans le mésencéphale. Bien que la majorité des cas soit sporadique, environ 10% des patients ont une forme familiale de la maladie. Des mutations pathogènes de PRKN ou PINK1 cause la maladie de Parkinson à début précoce. La voie PINK1/parkin est responsable de l’élimination des mitochondries endommagées via mitophagie. PINK1 est une kinase qui régule l’activité de la E3 ligase parkin assurant que parkin ne devient actif qu’à la suite de dégâts aux mitochondries. Malgré le progrès dans les …  Lire la suite

Premièrement publié en 2013, le recueil de nouvelles, Cuerpo adentro : Historias desde el clóset, édité par Rául Serrano Sánchez, constitue une des premières œuvres équatoriennes présentant des histoires spécifiquement par et sur les corps cuy(r). Les deux nouvelles que le mémoire examine, "Princesa de Navidad" de Jennie Carrasco Molina et "La Venus Impropia" d'Eduardo Adams, traitent des personnages non normatifs alors qu'ils naviguent dans la vie urbaine du Quito contemporain, et détaillent les manières complexes dont leurs identités sont mises en évidence, élidées, contestées, fragmentées et (hyper)sexualisées. En examinant les processus de la désidentification, de l’abjection et de l’imaginaire …  Lire la suite

The Purpose of this thesis is to present a comprehensive survey of Kant’s political theories, and to compare them with earlier thinkers to which they are related. The choice of this topic is due in the main to two considerations. First, the writer has observed with concern the social and political ills of our Western Civilization - the disintegrating family life, the individual's disillusion with democracy, his selfish, cynical disregard towards his fellow man, his attitude towards the state of getting the most and giving the least, the slow erosion of values and the prevalent contempt of inspiring ideals.  Lire la suite

Horseradish peroxidase (HRP) enzyme catalyzes the oxidation of aqueous phenols by hydrogen peroxide resulting in the formation and precipitation of polymeric products. The technical feasibility of this enzymatic process for the treatment of industrial wastewaters that contain phenols was investigated. Bench-scale experiments were conducted in which the influences of selected components in the waste matrix on treatment efficiency were assessed. Experiments with synthetic phenol solutions revealed that the toxicity of HRP-treated phenol solutions declines with time and is dependent on the presence of protective additives, the mode of reagent addition, and the presence of wastewater constituents. Also, many phenolic solutions …  Lire la suite

The goal of this thesis is to develop a binocular controller for artificial vision systems, based on principles used in biological binocular control. The controller is a symmetrical, two-sided system utilizing feedback across the midline. In spite of its simple topology, the controller allows for the integration of various aspects of eye movements, which are often modelled as independent systems. In addition, the controller topology naturally lends itself to sensory-fusion. The controller was applied to an artificial vision system and its 3-D tracking performance was evaluated. Eye (camera) movements consist of an appropriate mix of slow (tracking) and rapid (reorienting) …  Lire la suite

In 1905 Langevin gave the first satisfactory account of the magnetic properties of materials. His work was based on the configuration of the electron shells and sub-shells in the atom, that is, on the magnetic moment of the atom. With the exception of some additions resulting from the quantum theory of the solid state, Langevin’s work still remains the basis for the modern theory of magnetism. Now the experimental work carried out by the writer involved a study of the diffraction patterns of silver (diamagnetic) and tin (paramagnetic). The nature of these diffraction patterns depends on the crystal structure of …  Lire la suite

A microscopic examination of thin sheets of certain kinds of mica, notably biotite, reveals the presence of small areas containing groups of concentric circles darker in colour than the surrounding mica. Usually a minute particle, more or less transparent, is observed at the centre of each circle. The circular marks are called pleochroic haloes and the particle at the centre is commonly referred to as the nucleus. Joly and Rutherford (1) were the first to show that the haloes are due to darkening of the mica by alpha particles emitted by radioactive material associated in some way with the nucleus. …  Lire la suite

The purpose of this study was to examine the effects of a school-based wellness program, Looking Good...Feeling Great! (Zacour & Zacour, 1991), on ninth grade students' wellness levels, and to evaluate student and teacher impressions of the program. Experimental groups (n = 62) from one urban and two suburban secondary schools participated in the four day 175 minute Looking Good...Feeling Great! program, while control groups (n = 37) from the same schools followed their regular academic schedules. All participants completed TestwellTM (National Wellness Institute, Inc., 1994), a wellness inventory for high school students, as a pretest, one week later as …  Lire la suite

Vector fields arise from experiments and simulations in many scientific and engineering disciplines. The visualization of this data is important to understanding the inherent, nature of the field-generating process as well as providing an intuitive notion of the system's behavior. This thesis addresses some of the limitations in the flow visualization technique of Langer et al. [19]. One drawback of their method is that it uses a static uniform resolution grid. It cannot add more resolution in highly varying areas of the field without increasing the resolution for the entire grid, which comes at a substantial cost. We extend the …  Lire la suite

Hamdy, C Reggie (Internal/Supervisor)  Lire la suite

La transcriptase inverse (RT) du virus de l'immunodéficience humaine de type 1 (VIH-1) possède deux activités: polymérase et ribonucléase H (RNase H), en faisant l'enzyme clé pour le cycle de vie du VIH puisqu'elle convertit l'ARN viral génome en ADN à double brins. Des études portant sur des acides nucléiques modifiés chimiquement sont ici décris afin de: (1) mieux comprendre les procédés biochimiques sous-tendant la transcription inverse du VIH-1, (2) synthétiser des agents antirétroviraux dirigés contre de nouvelles cibles de la RT, et (3) développer des méthodes de criblage incorporant des analogues de nucléobase fluorescente afin de découvrir de nouveaux …  Lire la suite

Dhahran, Saudi Arabia is home to the largest transnational oil corporation and gated suburban residential compound in the world. In exploring Saudi ARAMCO, I will undoubtedly be opening to the centerfold of all socio-cultural, religious, political, economic and pedagogical forces affecting today's geo-political affairs. The theoretical focus of my thesis comes from both a global and critical pedagogy framework that investigates the nature of asymmetrical power relations on micro, meso and macro levels. Additionally, the multiple perspectives I have gained while living in Dhahran and mediating between identities including girl, woman, South-Asian, Canadian, expatriate, student and artist have provided me …  Lire la suite

Gélatine, un biopolymère de protéine peut être facilement dérivé la biomasse marine. Études ont été menées sur des sources différentes de gélatine marine, cependant, il n'y a encore peu de recherches sur les films formés à l'aide de la gélatine de calmar. Pour cette étude, la gélatine a été extraite des taupes de calmar (Illex argentinus) en utilisant une méthode enzymatique assistée par plus précisément de la pepsine, dans des conditions de réaction différente; concentrations de l'enzyme de 25, 15 et 5 U de pepsine/g de calmar déshydratés, températures d'extraction de chaleur de 45 °C, 55 °C et 65 °C …  Lire la suite

This study investigated the possibility of using ground-based remotely sensed hyperspectral observations with a special emphasis on detection of water, weed and nitrogen stresses contributing towards in-season decision support for precision crop management (PCM). A three factor split-split-plot experiment, with four randomized blocks as replicates, was established during the growing seasons of 2003 and 2004. Corn (Zea mays L.) hybrid DKC42-22 was grown because this hybrid is a good performer on light soils in Quebec. There were twelve 12 x 12m plots in a block (one replication per treatment per block) and the total number of plots was 48. Water …  Lire la suite

Cette thèse analyse les caractéristiques des radiations d'un téléphone mobile cellulaire semi-peuplé utilisant deux antennes imprimées en F-inversé (PIFAs). L'enquête est réalisée à trois fréquences différentes; la bande LTE 13 (746-786 MHz), GSM-900 (890-960 MHz) et GSM-1800 (1710-1880 MHz). Le téléphone mobile est constitué d'une batterie et d'un écran LCD dont le but est de rendre le modèle étudié plus réaliste. Le modèle utilisé vise d'abord à représenter la conception des PIFAs et ceci avec d'autres composants. Par référence a la méthode de conception qui a été décrite, les antennes de trois semi-peuplées téléphones mobiles sont conçus pour satisfaire des …  Lire la suite