McGill University Thèses et mémoires par auteur commençant par J

Les caillots sanguins sont des solides gélifiés formés par la coagulation du sang en réponse à des blessures. Ils scellent mécaniquement les vaisseaux sanguins endommagés pour assurer l’hémostase et servent biologiquement de structures temporaires favorisant la régénération des tissus. Cependant, les caillots sanguins sont intrinsèquement lents à se former et présentent une faiblesse mécanique en termes de résistance à la rupture et d’adhésion. Cela constitue un risque important de complications graves, telles qu’une hémorragie menaçant le pronostic vital et une régénération compromise en raison de la formation défaillante, de la rupture ou du détachement des caillots. Ces limitations des caillots …  Lire la suite

Kinsella, Joseph (Supervisor1)  Lire la suite

Carrieri, Francesca (Supervisor1)  Lire la suite

A mining complex is an integrated mineral value chain that consists of multiple interconnected components, from the extraction of ore to a set of sellable products. Over the last decade, advancements made in the field of mine planning have led to the development of simultaneous stochastic optimization of mining complexes. The cutting-edge framework of simultaneous stochastic optimization moves away from considering the economic value of blocks to the value of final products, allowing integrated value chain modelling and optimization. This thesis studies the simultaneous stochastic optimization framework through two real-world case studies, applying the methods and assessing the ability, impact, …  Lire la suite

Ahi-1 was initially identified as a common helper provirus integration site on mouse chromosome 10 in 16% of Abelson pre-B-cell lymphomas and shown to be closely linked to Myb proto-oncogene. By using long-range restriction mapping, we have mapped the Ahi-1 locus approximately 35 kbp downstream of the Myb gene. To test whether provirus integration in the Ahi-1 region enhances the expression of Myb by cis-acting mechanism, we have also examined Myb gene expression in A-MuLV-induced pre-B-lymphomas. Our data have revealed that there is no clear evidence for such activation in the tumors we have tested, indicating that provirus insertion in …  Lire la suite

Tyler Churchward-Venne (Supervisor2)  Lire la suite

Crop yield prediction and mapping are essential for crop management and decision-making. Advances in remote sensing (RS) and machine vision have significantly facilitated the development of non-destructive crop mapping in precision agriculture. In recent years, lightweight unmanned aerial vehicles (UAVs) have been widely used for the acquisition of high-resolution imagery for monitoring and evaluating crop growth and development. In this study, a cost-effective yield mapping workflow was designed and implemented in a commercial setting. Two UAVs were deployed to rapidly obtain RGB and multispectral images of many spinach fields in multiple stages of growth to assess spinach physiological attributes in …  Lire la suite

L'adaptation de maillage pour la simulation de grands tourbillons (LES) est un problème non trivial. Le défi de l'estimation des erreurs pour l'adaptation de maillage dans LES repose sur deux aspects. Premièrement, la source d'erreur dans LES inclut le couplage inhérent de l’erreur de modélisation et de l’erreur numérique, et la dissipation numérique joue une contribution importante à l'erreur totale dans LES puisqu’elle change l’énergie cinétique turbulente capturée (TKE) et son impact est difficile à estimer. Deuxièmement, les équations LES représentent un système chaotique pour lequel de nombreux estimateurs d'erreur prometteurs ne peuvent pas être appliqués, y compris l'estimateur d'erreur …  Lire la suite

Lessard, Larry (Supervisor1)  Lire la suite

Van de Ven, Theodorus G. (Supervisor)  Lire la suite

This study examined the effects of three computer-assisted cuing programs on the observational learning of a Tai Chi action sequence by thirty-one novice adult learners. Digital video demonstrations with visual cues, verbal cues, and both visual and verbal cues as well as no cues were presented. On the first and fifth trial participants completed a cognitive resequencing task, and on each of five learning trials attempted to physically perform the sequence. A retention test was also administered. The Pictorial Cognitive Resequencing Task results were somewhat equivocal as some of the treatment programs facilitated enhanced performance but participants in the "control" …  Lire la suite

Le maïs est une culture vivrière d'importance mondiale. Le rendement optimal et la qualité de la culture du maïs dépendent de l'absorption de l'azote (N), qui est fourni principalement par le nitrate (NO3-) dans le sol. Comme la transpiration contrôle la quantité d'eau du sol contenant du NO3- qui atteint la surface des racines, le manque d'eau pourrait limiter l'absorption de NO3- par le maïs. Ma recherche de doctorat a évalué la plasticité du système racinaire du maïs, en tant que stratégie adaptative qui pourrait soutenir l'absorption d'azote dans des conditions de manque d'eau et de limitation de l'azote. Les …  Lire la suite

Silicon (Si) has many beneficial effects on plants. Its cycling in terrestrial ecosystems plays a vital role in the global biogeochemical cycle. Temperate tree species differ greatly in their capacity to accumulate Si, but the implications for such variations for soil biogenic silica (BSi) concentration remains poorly understood. This study aims to (i) explain the effect of tree species on soil BSi by assessing leaf and soil BSi in 19 temperate tree species; (ii) study the effects of species and functional diversity on leaf and soil BSi; and (iii) link leaf Si to plant functional traits. The study was conducted …  Lire la suite

31P NMR spectroscopy was further developed for the structural elucidation of lignin by undertaking a series of systematic studies. More specifically, a detailed model compound investigation showed that 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane is an additional phosphitylation reagent which may provide further quantitative structural information about lignin. Correlation analysis using the Hammet principles revealed that the 31P chemical shifts of lignin- related phenolic hydroxyls with various substitution patterns strongly depend on the nature of the substitution. Such structure-chemical shift correlations led, for the first time, the development of a set of empirical parameters that permits the accurate prediction of 31P chemical shifts of lignin-related …  Lire la suite

Previous studies suggest an interesting divergence between the visual system’s response to contrast at threshold compared to suprathreshold levels. Despite a strong reduction of contrast sensitivity at, for example, high spatial frequencies or increasing eccentricities, suprathreshold perceived contrast is largely independent of these factors, remaining consistent across different spatial frequencies or eccentricities, demonstrating “contrast constancy”. While it is established that human red-green colour vision has a more dramatic decline in sensitivity across eccentricity than achromatic vision, there have been relatively few measurements of suprathreshold contrast effects. Here, we use a suprathreshold contrast matching paradigm to measure how perceived contrast differs …  Lire la suite

Cette thèse propose un examen critique des romans shouchao ben (manuscrits recopiés à la main) dans la Chine socialiste. Bien que la Révolution culturelle chinoise (environ 1966–1976) soit souvent étudiée comme une période de rigidité politique et de pénurie culturelle, les romans recopiés à la main, parmi d’autres formes de culture populaire, circulaient de manière informelle parmi les jeunes et les intellectuels. En m’appuyant sur des manuscrits collectés en Chine, j'explore comment les domaines de la littérature populaire et de la littérature officielle ont interagi pendant cette période. À travers une analyse approfondie de thèmes clés tels que la temporalité, …  Lire la suite

Cette thèse se compose de trois essais sur l'implication de trading multi-marchés sur la liquidité et les spreads de CDS. Le premier essai d'évaluer les avantages de la diversification potentiels de la détention d'actions transversales inscrites dans une perspective du risque de liquidité. En examinant la structure de dépendance entre le portefeuille du marché des États-Unis et de cotations croisées 1950-2012, je trouve que la corrélation linéaire moyenne, corrélation de rang, et la queue dépendance des innovations de liquidité sont notamment inférieurs à ceux des rendements du portefeuille. La solution du problème d'optimisation de portefeuille dans le cadre Mean-Variance-liquidité montre …  Lire la suite

De nouvelles fenêtres d’observation de l’univers à haut redshift s’ouvrent, remettant en question le modèle cosmologique standard. Les fluctuations gaussiennes prédites par le modèle standard de mati`ere noire froide Lambda rencontrent des difficultés à expliquer certaines observations à haut redshift. Les cordes cosmiques, en tant que perturbations non gaussiennes supplémentaires dans l’univers primordial, pourraient accélérer la formation des structures et résoudre certains de ces problèmes. Cette thèse explore l’impact des cordes cosmiques sur la formation des structures à haut redshift. Après une introduction générale, elle se compose de trois articles publiés. Le premier article calcule analytiquement la distribution des halos …  Lire la suite

L’observation de nombreux quasars à grand décalage vers le rouge ayant une masse supérieure à 10^9 M_⊙, ainsi que la fusion récente de deux trous noirs de masse intermédiaire, augmentent l’intérêt pour l’origine des trous noirs supermassifs (SMBH) et des trous noirs de masse intermédiaire (IMBH), qui représentent des énigmes dans le modèle ΛCDM. Les cordes cosmiques supraconductrices permettent de résoudre conjointement ces deux mystères. Les cordes en boucles créées tôt dans l’évolution de l’univers génèrent des surdensités non linéaires, qui pourraient constituer les germes de ces trous noirs. La mise à l’échelle des boucles donne lieu à une distribution …  Lire la suite

Eutrophication resulting from phosphorus (P) accumulation in water systems has been a worldwide concern for three decades. Agricultural soils are known to be an important non-point source of P in waterways. The objectives of this research are to identify agricultural management practices that reduce the risk of P loss from soils, and to investigate the underlying mechanisms of P retention and loss from soils. In the short term (4 years), dissolved P loads were not affected by tillage and were similar in corn (in a continuous corn rotation) and soybean (in a soybean/corn rotation) production systems. Soils amended with composted …  Lire la suite

L'analyse des valeurs propres est largement utilisée dans les études de stabilité des réseaux électriques. En utilisant les ordinateurs personnels disponibles aujourd'hui, le calcul de la totalité des valeurs propres de plusieurs grands réseaux électriques interconnectés requiert beaucoup de temps. Étant donné que les lignes de transport d'électricité sont connectées et déconnectées et que les charges ne cessent de varier, le suivi des valeurs propres en temps réel nécessite des calculs en parallèles. Récemment, une méthode de calcul en parallèle des valeurs propres, la Break et Bind (B & B), a été proposée par le Dr. H. M. Banakar à …  Lire la suite

In this dissertation, we study the relationship between eye movements and visual attention. Different types of eye movements are investigated including microsaccades, eye fixation, and eye pursuit. First, we demonstrate that microsaccades occur during pursuit and they are linked to covert attention shifts. Employing a psychophysical task that involves covert attention shifts to a peripheral square, we detect if microsaccades occur during eye pursuit, and, if so, whether, and in what way, microsaccades are related to attention shifts. Microsaccades are found to occur during pursuit and they present in similar patterns as those occurring during eye fixation. We discover that …  Lire la suite

Murai, Keith (Supervisor2)  Lire la suite

A review of psychiatric classifications in use throughout the world (STENGEL, 1960) reveals that only four out of 38 diagnostic systems provide a classif1ing label for a condition as familiar to clinicians as the schizophrenic residual, or "defect", state.+ The Diagnostic and Statistical Manual ot the A.M.A. (1952) reserves the term Schizophrenic reaction, residual type, for "those patients who, after a definite psychotic, schizophrenic reaction, have improved sutficiently to be able to get along in the community, but who continue to show recognizable residual disturbance of thinking, affectivity, and/or behavior." [...]  Lire la suite

Pain does not discriminate in the way it makes us feel. Men do not feel pain differently than women, but they do experience it differently, perhaps due to encultured patriarchal hegemonic ideals of masculinity. Upholding ideals of Hegemonic Masculinity have shown profound influence on both genders in the society. However, the extent to which it affects men’s health, their help-seeking behavior, coping mechanisms, therapeutic outcomes and health-related quality of life, still remains unclear. A person’s wellbeing is a multidimensional phenomenon and hence reducing it to just their biology is ineffective in understanding its complexity. In order to develop a holistic …  Lire la suite

This dissertation examines representations of the city and media art in Hong Kong from the late 1980s to the present to establish a link between the ways in which the city's place identity is re-imag(in)ed. Charting the course of media art in Hong Kong in relation to the parallel development of contemporary art in the region, it provides critical analyses of dominant urban metaphors that play a significant role, both locally and internationally, in the current representation of Hong Kong and its artistic practices. Specifically, the study explores how media artists have been dealing with four central urban metaphors that …  Lire la suite

Degeneration of the lumbar disc, which frequently leads to low back pain, is an age related disease that often diminishes a patient's quality of life. Despite the continued efforts of research in this area, biological understanding of the disease remains unclear. The treatment strategies are few, with the gold standard being fusion of the motion segment, which permanently prevents any motion at the treated level of the spine. Although there are several new treatments available that attempt to recover some mechanical function of the motion segment, such as arthroplasty, they all remain unsatisfactory in doing so. The biggest challenge that …  Lire la suite

Matthew Harrington (Supervisor2)  Lire la suite

La modélisation et la simulation multicorps sont devenues impératives pour plusieurs applications, allant de la rétroaction des boucles de contrôle aux simulateurs d'apprentissage à haute fidélité. La présence de corps déformables dans les systèmes multicorps a été étudiée considérablement dans la littérature, aboutissant à des formulations remarquables qui expliquent leur comportement. Cependant, les scénarios impliquant des corps subissant de grandes déformations et des rotations continues posent encore des défis considérables dans la recherche d'algorithmes qui sont efficaces, mais qui demeurent compatibles avec les formulations employées pour représenter le reste du système.Par conséquent, l'objectif principal de cette investigation est de simuler …  Lire la suite

Relaying techniques, in which a source node communicates to a destination node with the help of a relay, have been proposed as a cost-effective solution to address the ever increasing demand for high data rates and reliable services over the air. As such, it is crucial to design relay systems that are able to not only provide high spectral efficiency, but also fully exploit the diversity of the relay channel. With this objective in mind, this thesis investigates achievable rates, power allocation schemes, and code designs for half-duplex (HD) and full-duplex (FD) amplify-and-forward (AF) single-relay systems.The first part of the …  Lire la suite

Diversity is a powerful technique to improve the reliability of digital communications systems over wireless channels. In this thesis, the error performance and precoder design of a bandwidth-efficient bit-interleaved coded modulation with iterative decoding (BICM-ID) system over a non-orthogonal amplify-and-forward (NAF) half-duplex single-relay channel is investigated to effectively combine cooperative, time and modulation diversities. At first, a tight union bound on the asymptotic bit error probability (BEP) of the NAF-BICM-ID system employing signal space diversity (SSD) via a precoder is derived for an arbitrary cooperative block length of 2N. This bound provides a useful tool to predict the error performance …  Lire la suite

Kuhnlein, Harriet V. (Supervisor)  Lire la suite

The vestibular system is essential to ensure that self-motion information is processed, giving rise to vital reflexes alongside perception. Here we investigated the feasibility of using viral vectors to express opsins within neurons in central vestibular pathways of non-human primates (NHPs). Importantly, we chose our vector constructs while considering the functional relationships and anatomical differences between our regions of interest, which span from the brainstem to the cerebral cortex. Using optogenetics would allow for fine manipulation of vestibular pathways in vivo, increasing the potential of our understanding of how vestibular neurons represent sensory input. Due to our shared bipedality and …  Lire la suite

Optical transmission measurements were made through samples of CuInSe2 at room temperature, in the wavelength range 1300 to 1600 nm, beyond the energy gap absorption edge. The samples used were polished wafers about 1 mm thick, obtained from Bridgman ingots of monocrystals of the compound, grown from melts containing from 0 to 11 atomic % of elemental sodium (Na), plus excess over stoichiometry, x of selenium, corresponding to the formula CuInSe_(2+x), where x varied from 0 to 0.4. From the measured transmission, thickness and an assumed reflectivity value, absorption coefficient values (α) were obtained, which were found to decrease to …  Lire la suite

Uveal melanoma (UM) is a rare but deadly disease that currently lacks effective preventative or systemic treatment. Key genetic events at different stages of disease progression have been identified in recent years. However, a clear understanding of the mechanistic role of each event in the development of the disease is still lacking. We are interested in one of the early mutations identified, guanine nucleotide-binding protein G(q) subunit ???? (GNAQ). Interestingly, GNAQ mutations have also been found in over 80% of nevi cases, which mostly remain benign. This indicates that GNAQ mutation alone is not sufficient for malignancy in UM. In …  Lire la suite

The dynamic characteristics of engineered-to-order (ETO) environments are in conflict with the basic assumptions of Manufacturing Resource Planning (MRP) systems, which makes MRP based manufacturing planning systems fail to meet the needs of ETO companies. ETO environments are complex and require sophisticated planning techniques. In fact, the shortcomings of planning and scheduling systems are exacerbating the ability of ETO companies to reduce manufacturing cycle times. This thesis presents an overview of ETO environments and related manufacturing planning and scheduling systems. The reasons for the failure of present MRP systems to address ETO environments are discussed along with an analysis of …  Lire la suite

In the recent years, we have witnessed an increased interest in space-time coding, because of its effectiveness in overcoming the impairments due to the signal fading phenomenon. A large number of such codes require channel knowledge for decoding. Therefore, research in the area of channel estimation for space-time coding is very important. This thesis deals with the application of the Kalman Filter (KF) to channel estimation in space-time coded systems. For the purpose of deriving such an estimator, we model the multiple antenna channel as a first order Autoregressive process. As test cases, we employ the Alamouti's code as well …  Lire la suite

The traditional way of processing milk is the application of heat to destroy undesirable microorganisms. Though heat is an effective means of doing the job, it is associated with several limitations. High pressure (HP) processing has the potential for eliminating microorganisms without affecting the natural quality of the raw material. As a result, it has become a promising technique in recent years. Many factors are reported to influence HP destruction of microorganisms, the most important ones include food composition (i.e., lipid, carbohydrate and protein contents), water activity, process temperature, and mode of pressure treatment. Therefore, the objectives of this research …  Lire la suite

Contexte : La modulation conditionnée de la douleur (MCP) est un phénomène de "douleur contre douleur" par lequel un stimulus nocif atténue la douleur perçue causée par un autre stimulus nocif sur une autre partie du corps. Un stimulus nocif induit des signaux oscillatoires neuronaux dont les rôles fonctionnels restent à déterminer. Par exemple, la synchronisation des rythmes bêta a été proposée pour refléter la modulation descendante de stimuli douloureux. Par conséquent, l'examen de la façon dont la MCP affecte les signaux cérébraux induits par la douleur pourrait permettre de mieux comprendre les processus corticaux impliqués dans la MCP et …  Lire la suite

Le code de Reed-Solomon (RS) fait parti d'une importante classe de codes à maximum distance séparable (MDS), et a été largement utilisé dans plusieurs systèmes de communications (avec ou sans fil) pour contrôler les erreurs de transmission. Il est bien connu que le code RS peut corriger plus d'effacements que d'erreurs et donc le Décodage d'Erreur-et-Effacement (EED) peut potentiellement surperformer le Décodage d'Erreur (ED). Pour marquer les symboles à basse fiabilité en tant qu'effacements, il faut établir une technique convenable pour marquer les effacements. Les études effectuées antérieurement ont montré qu'un seuil peut être utilisé pour marquer les symboles en …  Lire la suite

Every underground excavation technique has shortcomings (e.g., low productivity, high cost). Heating rocks with microwave energy before excavation can change their mechanical properties and reduce rock strength. Microwave-assisted rock fragmentation not only reduces equipment maintenance costs, but increases drilling penetration rates and productivity. Mineral processing can also benefit from the micro-fractures created by this promising novel technique. The effect of the presence of water during rock microwave heating of rocks is poorly understood and serves as the objective of this thesis. Temperature distributions and mechanical properties (abrasiveness and tensile strength) were measured in stacked basalt disks in saturated and dry …  Lire la suite

In many exciting modern video games, one of the player's main tasks is to move and control the "hero" or alter-ego on a curved path. This is also a key issue in more serious applications like an automobile driver training simulator. In order to determine where the vehicle is at any time, while the speed is controlled with the trainee's accelerator pedal, we need a computationally efficient way to establish this position by, say, defining an arc length parameterized curve to represent the "road" or other trajectory constraint. To compute the are length of a parametric curve or define the …  Lire la suite

Mucciardi, Frank (Supervisor)  Lire la suite

Pinsonneault, Alain (Supervisor2)  Lire la suite

Electrophoretic deposition (EPD) of graphene oxide (GO) has obtained growing attention due to its deposition simplicity and cost-effectiveness. Moreover, EPD is an environmentally friendly process and has easy scaling up possibilities towards large substrate size with almost no limitation in substrate shape. Adhesion between the film and the substrate is critical for functional coating applications and electronic devices as it dictates coating lifetime and electron transport between the two layers. Although, EPD has shown to promote good adhesion of GO on various substrate materials, no in-depth study has been performed on interfacial development or dynamic mechanical behavior of EPD GO …  Lire la suite

The purpose of this study was to investigate the psychometric properties of swimming rubrics. The 10-level rubrics were designed to assess the front crawl. Participants were children, aged 8 to 13 years, with and without a physical disability (n=19) from a "reverse integration" school in Montreal. Participants swam 20 meters with each deciding if a floatation device was necessary. They evaluated themselves as well as peers using the rubric format. The physical education teacher and two teaching assistants participated as teacher assessors. Teacher, peer, and self assessments produced similar scores. In peer assessment, students with disability produced lower scores than …  Lire la suite

Malgré l’intérêt grandissant pour la veille concurrentielle, il existe peu d’études empiriques traitant du travail des professionnels oeuvrant dans ce domaine. La présente étude pose trois questions de base: qui sont les professionnels faisant de la veille concurrentielle; quelles sont leurs tâches et activités et comment sont elles réalisées; et finalement, quels facteurs limitent leur performance et capacité de compléter ces tâches et ces activités. À travers le Canada, 28 professionnels de la veille concurrentielle ont été recrutés pour l’étude représentant 24 organisations différentes dans 12 industries générales et 16 de type spécifique. Ces professionnels représentent des analystes, des gestionnaires …  Lire la suite

"Changing-look" quasars are a new class of highly variable active galactic nuclei that have changed their spectral type over surprisingly short timescales of a few years.The origin of this phenomenon is currently debated, but is likely to reflect some change in the accretion flow. To investigate the disk-corona systems in these objects, I use new Chandra X-ray observations and optical spectroscopy to measure optical/UV-X-ray spectral indices and Eddington ratios of ten previously discovered changing-look quasars at two or more epochs. By comparing these data with simulated results for X-ray binaries undergoing accretion state transitions,I find a likely similarity in spectral …  Lire la suite

A thorough taxonomic revision of the tribe Phisidini is completed. Fourteen genera and 96 species (of which 8 genera and 59 species are new) are described, redescribed or diagnosed and illustrated. Five previously described species are synonymized, one homonym is renamed. African species formerly assigned to Phisis are now excluded. The morphology of the tribe, particularly the terminology of the male genitalia, is clarified. A phylogeny of the tribe, upon which the classification is proposed, is suggested. Keys at both supraspecific and species levels are given. Details of known geographical distribution ranges and patterns for each species are indicated; the …  Lire la suite