McGill University Thèses et mémoires par auteur commençant par J

Near-field blast effects for centrally initiated spherical heterogeneous explosive charges have been investigated experimentally. The charges consisted of a packed bed of reactive particles saturated with a liquid explosive. Once the charge was detonated, the particles accelerated to high velocities and impacted a rigid plate or cantilever gauges. The positive phase pressure impulse at the rigid plate surface and the cantilever bend angles were measured at various distances. Comparison of the results for large diameter Zirconium (millimetre-sized) and small diameter Aluminum particles (sub-micron) suggested that the impact and fragmentation of the former contributed to the overall loading of the blast …  Read more

Kuhnlein, Urs (Supervisor)  Read more

The peculiar laws of quantum physics offer a mechanism for exploring fundamentally new types of information processing that promise unprecedented speed and security. Realizing this technology requires a quantum system that can be controlled with exquisite precision, and which can be duplicated and combined into a scalable quantum network. Quantized magnetic moments in diamond, controlled using light via an atom-like defect called the germanium vacancy center, are an example of such a system. The central goal of the work pursued in this thesis is to develop an efficient optical interface for such defects through coupling to an optical cavity, thereby …  Read more

Piotr Przytycki (Supervisor1)  Read more

The aim of this thesis is to address the dating, attribution, patronage, formal motifs, structural solutions, stylistic associations and historical context of the Chapel of the Assumption of the Virgin in the Slovakian town of Spissky Stvrtok. In the course of the text, it is revealed that the structure is a contained and coherent system of architectural forms that represents an international transmission of ideas, a continuous development of the architectural vocabulary of the Gothic, and the relevance of "the periphery" to a comprehensive understanding and appreciation of the Late Middle Ages. To that end, the chapel is shown to …  Read more

Mercier, Francois (Supervisor1)  Read more

This study examined two different strategies of learning with diagrams: drawing diagrams while learning or learning from pre-constructed diagrams. One hundred ninety six junior high school students were randomly placed in a condition either to draw while learning about how airplanes fly or to study from pre-constructed diagrams. Before the learning, students' prior knowledge and elaboration strategies were measured. During learning in either condition, students reported their mental effort. Afterwards, students' learning was tested on both a similar task and transfer task. Cook's (2006) theoretical framework, which combines prior knowledge and cognitive load theory on visual representations in science education, …  Read more

Les acides aminés azabicycloalcanes sont des mimétiques bicycliques de dipeptides appartenant à la classe des peptidomimétiques. La substitution d'acides aminés naturels par des acides aminés azabicycloalcanes maintient souvent l'efficacité et la tolérabilité élevées des médicaments peptidiques tout en améliorant leurs propriétés pharmacocinétiques. Par conséquent, au cours des dernières années, de nombreuses études concernant la conception, la conformation et la préparation de ces acides aminés bicycliques ont été menées.Dans cette thèse, nous avons tiré profit de ces structures bicycliques pour concevoir de nouveaux inhibiteurs doubles et covalents comme agents thérapeutiques contre le cancer. La prolyl oligopeptidase (POP) et protéine-α d'activation du …  Read more

Ragep, Faiz (Internal/Cosupervisor2)  Read more

La molécule BORIS (Brother of Regulator of Imprinted Sites) est une protéine de liaison à l'ADN qui est présente dans les testicules mais qui est exprimée d'une manière aberrante dans plusieurs types de cancer, d'où la désignation de BORIS comme un antigène du cancer testiculaire. La présence aberrante de BORIS dans certains cancers altère l'expression des gènes et engendre des modifications épigénétiques qui impactent des processus biologiques clés. Dans le cas des mélanomes, l'expression de BORIS est plus élevée dans les métastases que dans la tumeur primaire, ce qui indique que BORIS joue un rôle dans la progression des mélanomes. …  Read more

This dissertation is a comparison of local church conditions in three German Protestant church districts during the National Socialist era: the Nauen district in the Brandenburg Church Province of the Old Prussian Union Church, the Pima district in the Saxon Evangelical Lutheran Land Church and the Ravensburg district in the Wurttemberg Evangelical Land Church. It focuses on the attitudes and roles of the pastors, curates and vicars who served in the primarily rural parishes of these districts, analyzes the effect of the 'national renewal' that accompanied the National Socialist seizure of power upon the church conditions in their parishes, and …  Read more

Ivermectin has been a very useful drug for the control of diseases caused by helminths. However, the occurrence of drug resistant parasites is a major concern. In an attempt to mimic the conditions under which ivermectin resistance is selected for in the field, James and Davey (2009) generated the IVR6 and IVR10 Caenorhabditis elegans strains from a wild-type strain by growing them in the presence of sub-lethal doses of ivermectin for several generations. To better understand the mechanisms by which ivermectin resistance might arise, I have investigated the IVR6 and IVR10 strains. I found that the IVR6 and IVR10 strains …  Read more

La galaxie la plus brillante d’un amas (brightest cluster galaxy, BCG) se trouve au centre des plus grandes structures gravitationnelles de l’univers. Bien que certaines techniques de recherche d’amas identifient la position de cette galaxie et l’utilisent comme centre de l’amas, d’autres techniques peuvent ne pas inclure ces coordonnées. Pour les études de grande envergure, il est donc nécessaire de trouver un moyen rapide et fiable d’obtenir les coordonnées des BCG. Nous proposons l’apprentissage profond pour accomplir cette tâche et formons un réseau neuronal pour identifier les positions des BCG candidats en utilisant seulement des images photométriques multibandes. Nous obtenons …  Read more

We produce a nonpositively curved square complex, X, containing exactly four squares. Its universal cover, X̃ ≅ T4 x T 4, is isomorphic to the product of two 4-valent trees. The group, pi1X, is a lattice in Aut (X̃) but π1X is not virtually a nontrivial product of free groups. There is no such example with fewer than four squares. The main ingredient in our analysis is that X̃ contains an "anti-torus" which is a certain aperiodically tiled plane.  Read more

This dissertation explores representations of plants in German-language film and literature at the beginning of the twentieth century. Five examples serve as case studies, demonstrating the widespread preoccupation with the motif of the "dynamic plant" at the turn of the century. I argue that the preoccupation with the motif of the "dynamic plant" demonstrates the interconnectedness of two broad cultural transformations that helped to change the public's perception of plants from one that viewed plants as nearly inanimate objects to a world view that that saw plants as living, dynamic life forms similar to animals and humans. The first transformation …  Read more

The goal of the present research was to provide a structure for understanding the combinations of client attachment concerns, therapist interventions, and therapist interpersonal qualities that facilitate the development of strong therapeutic relationships by drawing upon the propositions of attachment theory and interpersonal theory. The first study supported the hypothesis that relationship incidents provide the relational information required for the client to feel secure enough with their therapist to explore in session. Following their third session, thirty volunteer clients seen by therapist trainees nominated an incident they felt was important to the development of their therapeutic relationship. General attachment was …  Read more

The HIV-1 protein Nef is a critical factor in the viral pathogenesis and decline of CD4 T-cells during HIV infection. Nef has been implicated in modulating several cellular pathways, including apoptosis. This thesis herein describes our attempt to elucidate the mechanism by which Nef modulates apoptosis in T-cells. Using Jurkat cells inducibly expressing wild-type Nef, we observe that Nef renders cells more sensitive to apoptosis upon cross-linking with anti-Fas or TRAIL. Enhancement of Fas-mediated apoptosis required the presence of Lck, as apoptosis was abrogated in Nef expressing Lck-/- cells as compared to wild type Jurkat cells. Nef does not modulate …  Read more

The prevalence in psychotherapy research of studies conducted with European-American clients has created a need for research on the impact of ethnicity and culture on the process of psychotherapy. This study tested a model examining the impact of client acculturation, individualism-collectivism and match in worldview between client and counsellor on the development of the therapeutic alliance and premature termination. Client openness was hypothesized to mediate the relationship between the cultural variables and the working alliance. Therapist multicultural competence was tested as both a mediator and a moderator of the impact of the independent variables on client openness and the working …  Read more

Cette thèse est composée de trois études portant sur des sujets liés aux différences de fécondité, des préoccupations de la consommation relative et de l'inégalité des revenus. Le premier chapitre étudie le lien entre l'inégalité des revenus et l'augmentation de l'endettement des familles à faible revenu causé par des préoccupations pour la consommation relative. Dans un environnement de l'augmentation de l'inégalité des revenus aux États-Unis les familles à faible revenu ont pu faire correspondre les nouvelles "normes de consommation" mises en place par les plus riches familles seulement en raison de la disponibilité accrue du crédit qui, contrairement à la …  Read more

Clarke, F. (Supervisors)  Read more

Strain rates ranging from 20% to 100% per second were used in consolidated-undrained triaxial tests, to investigate the influence of rate effects on the behaviour of cohesive soils. To apply the required loading rates, a hydraulic test unit was designed. Techniques were developed for producing saturated remoulded samples and for measuring the applied stresses, strain and pore pressures in the dynamic test. Electrical instrumentation was used for sensing and recording the transients. No pore pressure measurements were obtained in the dynamic tests conducted. For the same consolidation pressure, the strength of samples as determined in a triaxial test increased with …  Read more

Cette thèse explore comment les enseignants de langues des établissements post-secondaires de Montréal | Tio’tia:ke | Mooniyang conçoivent et mettent en œuvre des stratégies plurilingues pour soutenir leurs étudiants aux profils divers dans le contexte complexe du Québec. Fondée sur la théorie du plurilinguisme (Piccardo et al., 2022 ; CECR, 2020), cette étude examine la relation entre la perception des enseignants de leur propre compétence plurilingue et pluriculturelle, et leurs croyances et connaissances sur les langues et stratégies pédagogiques plurilingues telles que le translanguaging dans l’enseignement supérieur ; un environnement traditionnellement reconnu pour promouvoir le prestige de la langue dominante …  Read more

A detailed study of the evaporation of levitated copper droplets in presence of homogeneous condensation over a range of temperatures, from 1800 K to 2200 K, pressures, from 10 kPa to 101 kPa and inert gas flowrates, from 0.07 * 10-4 m3 s-1 to 7.40 * 10 -4 m3 s-1, was undertaken. Several calibration techniques to measure the temperature of a 5 mm copper droplet using a two-color pyrometer are described. The levitated droplets required a short time to reach steady temperature with the result that the average measured loss of copper by evaporation was less than steady state evaporation …  Read more

Cooper, Vincent Anthony (Supervisor2)  Read more

triggerings est une pièce pour mezzo-soprano et quatuor à cordes qui explore trois types dediscours définis comme suit: "Politique," "Ambigu," et "Poétique." D'une durée de 15 minutes, la pièce en un seul mouvement met en évidence les disparités entre chaque type de discours, chacun d'eux correspondant à un forme de "musicalisation" propre nommée "état musical" (musical state). Au cours de la pièce ces états musicaux coexistent mais parfois s'opposent violemment les uns aux autres, cherchant à monopoliser l'attention. La pièce utilise également le "Moment Form" dans une approche incrémentale. Bien que les troisétats musicaux s'entrecoupent régulièrement, et ce de façon …  Read more

The cap structure, m7GpppX (where X is any nucleotide), is present at the 5' end of all nuclear encoded mRNAs. Previous studies demonstrated that this structure facilitates the unwinding of mRNA 5' secondary structure through the action of eukaryotic initiation factors eIF-4A, eIF-4B and eIF-4F. eIF-4F contains three subunits of which one, eIF-4E, contains the cap binding site. To investigate the possible regulation of eIF-4E, an initiation factor whose limiting nature and activity have been implicated in the regulation of translation and cell growth, several murine cDNAs were isolated and characterized. Multiple mRNAs were shown to exist for eIF-4E, which …  Read more

La fabrication de plate formes anatomiquement et biomécaniquement correctes (communément appelées « fantômes ») sont des outils avantageux pour supporter le développement de dispositifs médicaux. Les fantômes conventionnels utilisent des matériaux qui ne peuvent pas reproduire toutes les propriétés des tissus biologiques de telle sorte que la validation des technologies médicales requière des tests pratiques avec des animaux. Le fantôme de coeur humain pour l’évaluation de la navigation des cathéters reproduit les propriétés de l’environnement in-vivo et biomécaniques du système cardiovasculaire humain en utilisant des hydrogels de polyvinyle d’alcohol (PVA). Des méthodologies pour créer les hydrogels de PVA afin qu’ils …  Read more

[...] In order to throw further light upon the exact nature of this polymer-thiol interaction, it was felt that it would be of interest to carry out a careful study of the role of atmospheric oxygen and other oxidizing agents whioh may be present in Systems of this kind. The work presented in this thesis, therefore, represents a study of these factors in the interaction of polybutadiene and polystyrene with a thiol in an emulsion medium.  Read more

A brief history of the application of mathematical methods to the study of fossils is followed by a fairly extensive treatment of the derivation of the formulae used in statistical studies of this kind. The mathematics has been kept as simple as possible. The main section of the paper is divided into four parts. Part One establishes the validity of the use of statistical methods in the field of Biology. In Part Two the use of graphical methods in the study of fossils is discussed. Scatter diagrams and pure statistical methods are reviewed in Part Three, whilst in Part Four …  Read more

Six experiments were conducted to address the role of phonological information in visual word recognition. A semantic decision task was used to ensure that word meanings were accessed. Experiments 1-4 showed that subjects make more false positive errors on homophone foils (e.g. living thing-FLEE) than on spelling controls (e.g. living thing-FLEX) only when both members of the homophone pair are uncommon and are similarly spelled. In Experiment 5, there was an increase in errors on low but not high frequency homophone category exemplars when they were preceded by a word related to the other member of the homophone pair (e.g. …  Read more

The importance of spatial variation in abundance for the assessment of climate change impacts was examined using the North American beaver ( Castor canadensis) in Quebec as a model species. A preliminary characterization of the beavers' range edge improved the core-sampling bias and revealed that beavers are present at low densities, in shrubby riparian habitats as far north as the communities of Tasiujaq and Umiujaq. Spatial variation in beaver abundance across the province follows a roughly logistic pattern, with abundance peaking in southern Quebec, declining steeply around 49°N, and remaining uniformly low as far as 58°N. Although climate sensitivity of …  Read more

La planification précise de l'irrigation est critique à l'amélioration de son rendement. C'est un outil technique et de gestion qui permet d'évaluer avec précision la quantité et la fréquence d'application de l'irrigation afin de répondre à la demande pour une croissance optimale des cultures. Cette planification est particulièrement difficile dans les régions humides, comme celles du sud-ouest ontarien, où l'humidité des sols est influencée par des pluies périodiques. Le but fondamental de ce projet de recherche de trois ans était d'étudier les différentes stratégies de planification de l'irrigation pour la production de tomates à Leamington, Ontario. Il y a eu …  Read more

Netrin-1 and its receptors play crucial roles during embryogenesis, guiding axon and neuronal cell migration. Here, roles of netrins and their receptors in glial function were investigated. In the embryonic spinal cord, netrin-1 expressed at the ventral midline orients axon extension. Spinal oligodendrocyte precursor (OP) cells are born close to, and migrate away from, the ventral midline. We find that OPs express DCC and UNC5 netrin receptors and, in an in vitro microchemotaxis assay, are repelled by a netrin-1 gradient. In the absence of netrin-1 or DCC function in vivo, fewer OPs migrate from the ventral to the dorsal embryonic …  Read more

Transportation infrastructure like railways and roadways is highly vulnerable to moisture-induced subgrade failures, particularly in areas with soft, fine-grained soils. Conventional drainage systems, including geotextiles, perform well under saturated conditions but poorly in unsaturated soils due to low hydraulic conductivity at high suction. This limits their ability to manage surface infiltration and capillary rise from a high water table. Wicking geotextiles offer a promising alternative, transporting moisture through capillary action to enhance drainage under unsaturated conditions. Most existing wicking geotextiles are woven and serve both drainage and reinforcement functions. However, the performance of nonwoven wicking geotextiles remains largely unexplored. This …  Read more

The use of aqueous film-forming foams (AFFFs) for extinguishing fuel fires has introduced poly- and perfluoroalkyl substances (PFAS) into different environmental media, including soil. Such contaminated sites are long-term sources of PFAS pollution, posing a threat to drinking water supplies in many locations. In situ soil stabilization using sorbent amendments, such as granular activated carbon and modified clay minerals, has demonstrated efficacy in immobilizing PFAS in contaminated soil. The measure is expected to be highly effective in reducing PFAS bioavailability to earthworms, the predominant soil invertebrates, but limited experimental evidence is available. Therefore, PFAS uptake from contaminated soils by earthworms …  Read more

There is experimental evidence suggesting that ethanol alters the activity of the endogenous opioid peptide systems in a dose and brain region dependent manner. These ethanol-induced alterations in opioid activity may influence the processes of ethanol reward and reinforcement. However, the precise nature of the link between ethanol-opioid interactions influencing reward and reinforcement is not clearly understood. Thus, it was the objective of the present study to investigate the response of the three major opioid peptide systems (endorphins, enkephalins, and dynorphins) to acute ethanol administration, at the level of the ventral tegmental area (VTA), a brain region important for drug, …  Read more

Satellite telecommunications, global navigation and remote sensing systems are key drivers in the ongoing transformation of an industrial based global economic order to one increasingly dominated by information services. A growing number of States are establishing an independent presence in outer space and all States (and indeed, individuals) can access a broad range of affordable space-related products and services (e.g., Google Earth imagery, GPS receivers, and global voice and data transmissions). Consistent with broad historical trends, these technologies are inevitably influencing the way States think about, plan for, and conduct warfare. Inspired by the prospect of seizing the ultimate "high …  Read more

This thesis addresses Les Faictz de Jesus Christ et du Pape, the first illustrated book of the French Reformation, printed by Pierre de Vingle in 1534, in Neuchatel. Historical analysis, close reading of the text, interpretation and commentary revealed that, contrary to what had until recently been believed, Les Faictz was more than a mere translation of Passional Christi und Antichristi, an anti-papal Lutheran satire, issued in 1521, in Germany. The analysis of the classical sources employed by the anonymous writer(s) also exposed the virulent attack directed by the radical French reformers against the medieval institution of the papacy. Moreover, …  Read more

Associative memories retrieve stored information given partial input patterns without requiring an explicit address as in indexed memories. A new family of associative memories based on Sparse Clustered Networks (SCNs) has been recently introduced that can store many more messages than classical Hopfield Neural Networks (HNNs). Hardware implementation of such memories benefits applications, where fast and parallel lookup operations are required, such as cache memory in processors, database search engines, network routers, pattern recognition in image processing, and even virus intrusion detection in data centres.In this dissertation, we first present a proof-of-concept hardware implementation of SCNs, and analyze its limitations. …  Read more

Les émotions ont des implications importantes pour l'apprentissage, la réussite, la rétention, et le bien-être. Cependant, le rôle de la régulation des émotions demeure un sujet de recherche peu exploré. Le but de cette dissertation est de combler cette lacune en explorant d'importantes questions théoriques, méthodologiques, et empiriques sur la régulation des émotions dans l'enseignement supérieur. Un examen des théories actuelles portant sur les émotions et leur régulation indique que les conceptions actuelles sur le sujet ne peuvent expliquer les mécanismes de régulation des émotions par rapport aux situations de réussite. Sur la base de cet examen, un cadre novateur …  Read more

This research examines the type of emotional responses medical students experience while solving virtual patient cases using BioWorld, a technology rich learning environment that provides feedback on diagnostic reasoning performance. Convergent methodologies were used to examine the physiological, behavioral and experiential emotional responses experienced when students encountered expected and unexpected events while problem solving. Participants (N = 15) were asked to solve two virtual patient cases in BioWorld by gathering relevant evidence such as ordering diagnostic laboratory tests. The results of these tests were either abnormal (expected) or normal (unexpected). As predicted, in response to the normal (unexpected) test results …  Read more