McGill University Thèses et mémoires par auteur commençant par K

Nicolau, Belinda Farias (Supervisor1)  Lire la suite

Lewis' theory of meaning is barely touched by the contemporary trend to substitute a patient examination of the use of words for theorizing in the traditional manner. By way of contrast, some of his epistemological and ethical writings look as if Lewis had fulfilled the promise of linguistic analysis before it was made by Wittgenstein. Lewis' discussion of the good looks like an anticipation of the linguistic method. The question "what is good?" is answered as if it read "how is the word 'good' used?" (1) In comparison, his discussion of meaning has an anachronistic air about it. [...]  Lire la suite

Methods are presented for improving the accuracy of the value of the diffusion coefficient used in continuum theory based simulation of ion channel permeation. A mathematical framework is derived for computing the diffusion coefficient of a spherical species undergoing diffusion confined within an arbitrarily defined container. Methods for standardizing the coordinates of the atoms constituting biological ion channels are presented. From its standardized coordinates, a method is described for rendering the channel's pore lining surface. This surface representation is used as the definition of the container in application of the mathematical framework for diffusion coefficient estimation within the channel's pore. …  Lire la suite

Requirements of electronic systems are increasing, as the applications for these systems become more complex and require more bandwidth. Optical interconnection can help satisfy these system requirements. In order for an optical interconnect to be successful, system design must satisfy new demands on the packaging of the optically interconnected devices, different from those encountered in packaging electronic interconnects. This thesis addresses the issues faced in designing the packaging for a two-dimensional array of surface active optoelectronic devices, within the framework of a free-space optically interconnected backplane. Two demonstrator systems' packaging are presented, as well as a general discussion of the …  Lire la suite

Acetylcholine has been implicated in the reorganization of cortex using lesion studies. These studies suggest that biochemical changes take place in the cortex following peripheral nerve injury. Using microdialysis, we studied the time-dependent change in the release of acetylcholine in control and sciatic-nerve-sectioned cats. Our first finding was that there is intra-animal variability in the release of acetylcholine. Using each cat as its own control we studied the acetylcholine release on days 1, 3, 5, 7, 9, 11 and 15 after nerve injury. We found that the release of acetylcholine was significantly higher than normal one day after nerve injury. …  Lire la suite

Mutations in the Cu/Zn-superoxide dismutase (SOD-1) gene are responsible for a familial form of the motor neuron disease, amyotrophic lateral sclerosis (fALS). Aggregation of mutant SOD1 and formation of cytoplasmic inclusions are pathological hallmarks of the disease in patients and in transgenic mouse models of fALS, and their occurrence suggests overload of proteolytic and protein chaperoning pathways. We studied proteasomal function in transgenic mice over-expressing human SOD-1 carrying the fALS-related mutation G93A (SOD1 G93A). Reduction in proteasomal activities in the lumbar spinal cord (containing vulnerable motor nuclei), but not thoracic spinal cord (less affected area) of pre-symptomatic SOD1G93A transgenic mice …  Lire la suite

This thesis is a description of educational retardation, or academic underachievement, in a stable, rural, Indian community in Quebec. It is a result of the writer's interest in the problem of educational retardation as distinct from mental retardation. The opportunity for first-hand study of this community developed during three and a half years' service as teacher in the one-room Oka Country Indian Day School.  Lire la suite

In recent years, there has been an increasing interest in kernel methods in areas such as machine learning and signal processing as these methods show strong performance in classification and regression problems. Interesting "kernelized" extensions of many well-known algorithms in artificial intelligence and signal processing have been presented, particularly, kernel versions of the popular online recursive least squares (RLS) adaptive algorithm, namely kernel RLS (KRLS). These algorithms have been receiving significant attention over the past decade in statistical estimation problems, among which those problems involving tracking time-varying systems. KRLS algorithms obtain a non-linear least squares (LS) regressor as a linear …  Lire la suite

En linguistique et en philosophie du langage, la sémantique et la pragmatique sont présentées comme deux aspects complémentaires et imbriqués du sens du langage. Le premier s'intéresse au sens littéral des mots et des phrases, un sens qui ne dépend pas du contexte, tandis que le second se concentre sur le sens implicite et dépend du contexte. Alors que dans le passé la recherche en traitement automatique de la langue (TAL) s'est concentrée principalement sur la sémantique, l'objectif de cette thèse est de développer des modèles qui exploitent cette connaissance pragmatique du langage qui est cruciale pour effectuer correctement de …  Lire la suite

Tarik Möröy (Internal/Cosupervisor2)  Lire la suite

L'extraction des métaux précieux à partir de minerais polymétalliques nécessite des approches géométallurgiques innovantes, en raison de la complexité croissante des gisements miniers. Cela est particulièrement crucial pour optimiser l'extraction des ressources provenant des gisements de métaux du groupe du platine (PGMs), dont la demande mondiale est en hausse. Les méthodes actuelles de comminution et de flottation s’avèrent souvent insuffisantes en raison de la variabilité des propriétés minéralogiques et de la baisse des teneurs, ce qui complique l’optimisation des paramètres de traitement et des taux de récupération.Cette thèse intègre l’analyse géométallurgique, l’apprentissage automatique (ML) et l’optimisation par essaim particulaire (PSO) …  Lire la suite

Schipper, Hyman M. (Supervisor1)  Lire la suite

Les alliages de magnésium de corroyage présentent une formabilité limitée à cause de leur structure hexagonale compacte et leur orientation cristallographique préférentielle. Plusieurs approches ont été envisagées pour modifier ou affaiblir leur texture défavorable et notre étude s’est focalisée sur la capacité des précipités, formés pendant et après déformation, à améliorer la formabilité.Deux alliages, Mg-3Al-2Sn (AT32) et Mg-3Al-3Sn (AT33) (en % en poids) ont été conçus à l’aide de la méthode CALPHAD dans le but de former, dans le cas de l’alliage AT33, des quantités significativement plus élevées de précipités en cours de déformation ou au cours d’un recuit post-déformation, …  Lire la suite

Organochlorine (OC) compounds that include several pesticides as well as an array of industrial chemicals were very efficacious for their intended use but were also characterized by deleterious environmental impacts when released either intentionally or inadvertently. Their lipophilic nature, long persistence in the environment and threat to human health caused all the developed countries to ban the production of these chemicals as well as restricted the use of formulations containing these material for food production. A number of scientists have become involved in the development of intentional degradation methods/techniques for these compounds using zero-valent metals or bimetallic mixtures. To date, …  Lire la suite

Mycorrhizal fungi are a major component of agricultural systems and play a key role in plant nutrition. Little is known about the effects of tillage practices and manuring on arbuscular mycorrhizal fungi (AMF). The purpose of this study was to evaluate the effect of soil disturbance on winter survival, development and distribution of AMF in soil and on plant nutrient uptake and productivity. This research was conducted in long-term corn plots in two soils and under controlled conditions. A growth chamber study with field soil demonstrated that most of the fungal hyphae with mycorrhizal plants were mycorrhizal rather than saprophytic. …  Lire la suite

Signal and power integrity have become a dominant performance limiting factor in the designof integrated circuits. This has led to the need for accurate time-domain models for signalinterconnects, power delivery networks, and other passive structures used for signal and powerdelivery. Such models are difficult to obtain using analytical physics based approaches. However,it is possible to characterize such structures by using measurement or full-wave simulationin order to obtain their sampled frequency-domain S - or Y-parameters. The objective of thisthesis is to develop a systematic and automated algorithm for obtaining a time-domain SPICEcompatiblemacromodel from measured or computed frequency-domain S - or Y-parameterdata. …  Lire la suite

Rhizoctonia solani (AG-3), the causal agent of Rhizoctonia disease of potato, overwinters as sclerotia on potato tubers. To develop a biocontrol strategy based on the prevention of the sclerotial germination, an isolation of microorganisms colonizing sclerotia of infected potato tubers (cultivars Norland, Atlantic and Souris), was conducted. In vitro screening was used to select effective antagonistic fungi against Rhizoctonia solani. Fifty fungal isolates were selected in order to cover all identified genera and potato variety and examined for their ability to inhibit germination of sclerotia which were incubated with the test fungus for 14 days. Twenty-four (24) fungal isolates were …  Lire la suite

Les histones jouent un rôle essentiel dans la régulation de l'expression des gènes au cours du développement alors que la dérégulation de ces processus entraîne des maladies telles que le cancer et des troubles neurologiques. Le gliome pédiatrique de haut grade (pHGG) est un cancer très agressif dont le taux de survie après deux ans est inférieur à 30 %. Grâce à la technologie du séquençage du génome entier (WGS), des mutations somatiques récurrentes dans les histones H3 en combinaison avec des mutations partenaires ont été identifiées comme étant à l'origine d'un sous-ensemble de cancers. Les mutations de la lysine …  Lire la suite

Quantitative microstructure characterization is commonly performed on thin foils using a transmission electron microscope (TEM) at the atomic scale spatial resolution. The main drawbacks of TEM include time consuming and destructive thin foil preparation, limited field of view and statistically unreliable results in the case of heterogeneous microstructures. Alternatively, quantitative microstructure characterization is performed on bulk specimens using field emission gun scanning electron microscope (SEM) at the nanoscale spatial resolution. In comparison to TEM, the main advantages of SEM include fast and non-destructive bulk specimen preparation and statistically reliable results from a large field of view in a bulk specimen. …  Lire la suite

Astrocytes are one of the most abundant glial cell types in the central nervous system (CNS). They extend highly ramified branches into the neuropil, between axons and dendrites, and encapsulate synapses. These small, neuropil-associated processes allow astrocytes to fulfill important functions including regulating extracellular neurotransmitter and ion levels. At the same time, specialized astrocyte processes known as perivascular endfeet cover nearly the entire cerebrovasculature. Perivascular endfeet are involved in activity-dependent regulation of cerebral blood flow, the formation of vascular basement membrane (BM), and the regulated exchange of substances across the blood-brain-barrier. Within astrocyte processes in the neuropil and in perivascular …  Lire la suite

Les sentiments d'être personnellement autonome et d'agir volontairement sont universellement associés au bien-être et à la vitalité psychologiques (Ryan et Deci, 2017). Aucune recherche jusqu'à date n'a étudié l'impact, sur l'autonomie personnelle, de ressentir que les groupes sociaux auxquels on appartient jouissent d'autonomie collective dans un contexte intergroupe. Le programme de recherche faisant l'objet de la présente thèse introduit le concept de l'autonomie collective, soit la perception subjective d'un individu que le groupe auquel il/elle appartient est libre de déterminer et de pratiquer sa propre identité culturelle, sans l'influence indue d'autres groupes dans la société. Par l'intégration de la théorie …  Lire la suite

RÉSUMÉLa plupart du temps, le domaine de motivation humaine est étudié du point de vu de l'individu, en prenant en compte seulement le contexte immédiat qui l'influence. Certes, cette approche est approprié : pour expliquer le comportement d'un individu, l'individu devrait être l'unité d'analyse. Par contre, de la recherche récente faite part Taylor (2002) et Oyserman (2007, 2009) suggère que les groupes sociaux, et les identités collectives auxquelles ils sont associés, influence la motivation personnelle et la capacité de s'autoréguler des membres individuels. Pour continuer cette recherche, nous proposons que pour comprendre l'état d'une personne individuelle, nous devons aussi prendre …  Lire la suite

A structural model in the frequency domain is developed to obtain aeroelastic solutions of a NACA64A010 in the transonic regime. Results from a fully nonlinear frequency domain flow solver and the structural model are compared to a state of the art time accurate flutter code. The prohibitive cost of using time accurate methods to solve problems in transonic aeroelasticity is introduced and then followed by an analysis of using a Non-Linear Frequency Domain (NLFD) approach. The computational cost and accuracy associated with using the NLFD method are compared with already established time accurate methods. In this work, an accurate representation …  Lire la suite

The liver is a major site of production of circulating levels of insulin-like growth factor-I (IGF-I) and IGF-binding proteins (IGFBPs). We have used primary cultured rat hepatocytes maintained under serum free conditions to explore the regulatory role of various hormones on hepatic IGF-I and IGFBP-1 mRNA levels. IGF-I mRNA levels were stimulated 2.0 to 2.5 fold by bovine growth hormone (bGH) and 1.8 to 2.0 fold by glucagon but on combining bGH and glucagon, a synergistic effect was observed and IGF-I mRNA level was augmented 10 to 12 fold. Octreotide blocked the hGH induced stimulation of IGF-I production in serum …  Lire la suite

In this dissertation, I reconceptualize the concept of violence to consider its physical, sexual, psychological and economic dimension. I attempt to add to existing meanings of "violence" to include not only forms of abuse on the individual and group level but also abuse practiced by legal, political, ideological and economic institutions in a collective and systemic manner. Due to the significance of child maltreatment around the globe, I focus on the impact of law on this problem specifically through a study of domestic and international use of the best interests' doctrine; evidentiary issues relating to children; child abuse reporting mechanisms …  Lire la suite

This thesis is a study of the Saundarya Lahari, a Sanskrit poem associated with the Srividya Sakta Tantric tradition. It traces the movement of meaning between textual, ritual, and cultural spaces in order to understand the performed possibilities of the text. The Goddess as Sakti (power) both grants enjoyment and is the principle of that enjoyment: beauty, love, and worldly powers. These powers follow the movements of the text: its scanning of the Goddess from shining head to toe; the twinned movements of publicity (exoterism) and secrecy (esoterism); and the gestures and utterances of ritual performance. First the text is …  Lire la suite

Farran, Andrea (Supervisor1)  Lire la suite

Zetka, Monique (Supervisor2)  Lire la suite

Candida glabrata is the second most common cause of candidiasis after Candida albicans. Recent studies on resistance to the antifungal drugs echinocandin and azole among Candida bloodstream infection isolates showed the prevalence of C. glabrata isolates. Zinc cluster proteins are fungal transcriptional regulators of genes involved in a wide variety of cellular processes including chromatin remodelling, gluconeogenesis and respiration, nitrogen utilization, meiosis and mitosis and drug resistance. However, the role played by zinc cluster proteins in C. glabrata is poorly understood. We have performed phenotypic analysis of 36 genes encoding C. glabrata zinc cluster proteins including 33 putative factors of …  Lire la suite

The integration of digital games into education has seen a marked increase in recent years, with a national survey indicating that more than half of K-8 teachers in the US use games in their weekly lessons. Despite its popularity, the effectiveness of this approach remains a matter of debate, with questions surrounding which factors contribute to its success. The quality and types of games, as well as the way in which teachers integrate games into their lessons, are the main factors that affect the effectiveness of game-based learning. These factors have been separately explored in previous studies, while others are …  Lire la suite

Dietary assessment methods are often plagued with inconsistent or inaccurate data. Self-reported intakes are particularly susceptible to error as research has shown that humans habitually report food intake inappropriately. Self-reported intakes have been used to create energy recommendations for populations. In order to assess energy intake, a novel 4 day multimedia dietary assessment method was developed utilizing a tape-recorder and camera in an attempt to more accurately quantify energy intake than traditional methods. The Recommended Nutrient Intakes for Canadians ( RNIC) provide population mean energy estimations. An objective was to determine whether the RNIC provides an accurate index of energy …  Lire la suite

Klissouras, Dr. Vassilius  Lire la suite

Background The ability to accurately determine extubation readiness in extreme preterm infants is important but difficult. Clinical decision making results in a 20-40% rate of extubation failure and strategies developed to predict successful extubation have shown limited success. Heart rate variability (HRV) and respiratory variability (RV) can distinguish weaning outcome in ventilated adults but have never been assessed in preterm infants undergoing disconnection from MV. Objectives Studies performed in extreme preterm neonates evaluated differences in HRV and RV prior to extubation between infants that would fail or succeed extubation. An additional study evaluated HRV and RV in healthy full-term newborns …  Lire la suite

Rytina, S. (Supervisor)  Lire la suite

Le diabète de type 2 (DT2) est une maladie complexe et progressive résultant del’interaction entre des facteurs génétiques et environnementaux. Cette maladie affecte la fonctiondes cellules-β ainsi que la sensibilité à l’insuline tissulaire. Le taux de progression de la maladieest principalement lié aux anomalies de la cellule-β. Une défaillance dans la compensation descellules-β, pour la résistance à l'insuline tissulaire prédominante est le principal déclencheur duDT2. De nombreux facteurs mènent à la défaillance des cellules β et à leurs décompensationséventuelles tels que l'hyperglycémie, l'hyperlipidémie, la stimulation chronique et l'effet altéré del'incrétine. Ces facteurs de stress ainsi que la capacité limitée de …  Lire la suite

The goal of WITS Welding Intelligent Tutoring System is to provide a realistic and safe virtual reality environment to train electrical workers in performing standard alumino-thermal ground welding procedures on equipment in an electrical switching station yard. The WITS training system allows users to practice a variety of welding scenarios which satisfy company practices and provides help, feedback, and a performance evaluation. The Virtual Reality Interface, Expert System, Virtual Environment, and Monitoring modules of WITS are presented. This thesis focuses on the monitoring of human interactions in the WITS Welding Intelligent Tutoring System. The Monitoring module design includes welding task, …  Lire la suite

Upon encountering sub-optimal conditions, early Caenorhabditis elegans larvae are able to alter their developmental program and enter the dauer diapause, an alternative stage that allows larvae to endure long periods of starvation and overcrowding. During this quiescent state, the germline stem cells, which normally proliferate during reproductive development, arrest their proliferation and are consequently rendered quiescent. Previous work has implicated a role for LKB1, AMPK and PTEN orthologues in germline stem cell quiescence. AMPK is a well-characterized downstream target of LKB1, but intriguingly the hyperplasia observed in LKB1 (par-4) mutants is more severe than AMPK-compromised dauer larvae, suggesting that LKB1/par-4 …  Lire la suite

Incompressible hyperelastic materials are used extensively in construction and manufacturing and are often reinforced with fibers aligned in a single direction. There are numerous mathematical constitutive models that are used to model the behavior of hyperelastic materials but few of them have been accurately applied to reinforced hyperelastic materials. The goal of this work is to develop a simple model that will allow a researcher to predict the effective shear modulus of a reinforced hyperelastic material in plane strain and model the material as if it were a homogenous material. A series of computational simulations were performed with reinforced hyperelastic …  Lire la suite

The gravitational field of objects such as primordial black holes should create an image pair of the waveform of a fast radio burst (FRB), where one image is delayed in its arrival time and has a smaller flux magnification than the other image. We search for a copy of FRB waveforms in observations from the Canadian Hydrogen Mapping Intensity Experiment (CHIME) by performing a time-lag auto-correlation with a matched filter. A gravitational lensing signal in the time-lag domain will appear as a statistically significant excursion. We model the statistics and test statistical significance with the use of the off-pulse telescope …  Lire la suite

The complex nature of Netochka Nezvanova, one of Fyodor Dostoevsky's early pieces, makes this work an interesting and revealing point from which to study the evolution of the writer's craftsmanship. Written under the influence of major Russian, French, and German prose works of the period, it reflects Dostoevsky's process of creative emulation of the achievement of European realist writing and a process of reworking of Russian Romanticism into what would later be called "psychological realism." The unfinished nature of Netochka Nezvanova testifies to Dostoevsky's struggle with the previous literary tradition and to his search for a new literary form. The …  Lire la suite

The transfer of an artistic work from the literary medium to the filmic medium presents technical, personal, social and political factors for consideration which are capable of revealing important information about the times in which both the literary work and the film work were created. In a Russian context, where both literature and film have played roles of central cultural importance, the study of this interaction can be particularly fruitful. The first chapter of this dissertation considers the theoretical aspects of adaptation, namely fidelity to the original work and questions of metaphor and narrative structure. After examining these issues in …  Lire la suite