McGill University Thèses et mémoires par auteur commençant par T

Cette thèse examine les schémas interlinguistiques de production et de perception des effets intrinsèques de f0 des voyelles (VF0) et des consonnes (CF0). Il existe de nombreuses preuves que les effets intrinsèques de f0 sont une source principale de processus de changement phonétique tels que la tonogenèse et les répartitions tonales. Pourtant, il reste à déterminer la raison pour laquelle ces processus se produisent plus souvent par effets CF0 que par effets VF0. D’abord, une étude de corpus a été réalisée pour examiner la distribution des effets VF0 et CF0 en production dans 20 langues, en se servant de vastes …  Lire la suite

RésuméPréambule: Il existe des preuves que les forces passives produites par titine des muscles squelettique sont liées avec la concentration de Ca2+. Plusieurs études montrent qu'il existe un lien positif entre la longueur des sarcomères et la force passive générée lorsque les tests sont faits dans des hautes concentrations de Ca2+ et lorsque les interactions actine-myosine sont abolies. Objectifs: Tester l'hypothèse qu'il y a un lien positif entre la concentration de Ca2+ et l'augmentation de la force passive lorsque les pontages croisés sont abolis. Hypothèse: La force passive augmente parallèlement avec l'augmentation de la concentration de calcium.Méthodologie: Les fibres musculaires …  Lire la suite

Developments in lithium-ion batteries for energy storage are currently focused on improving energy density, increasing cycle life, and reducing cost to match targets set by the automotive industry. An important class of cathodes known as Li-rich layered oxides is considered promising for next-generation electrode materials. However, a poor understanding of a number of detrimental processes that occur in Ni-containing materials, for which the underlying mechanisms are not clear, has hindered their commercialization. Numerous model systems have been studied in an effort to fully understand the discrete mechanisms taking place during battery operation. Herein, we build upon the previous work on …  Lire la suite

The present investigation has attempted to examine the cellular differentiation events which occur within T and B lymphocyte cell lines during the course of antigen-induced humoral antibody formation in the mouse. The data have supported the conclusion that the T cell line acts throughout all stages of the primary and secondary humoral antibody response to quantitatively but not qualitatively amplify the production of antibody by members of the B cell line. This amplification was demonstrated whether sheep erythrocytes or brucellin was employed as the immunizing stimulus. The data have also supported the hypothesis that the sequential production of humoral antibody …  Lire la suite

Quelles sont les causes des conflits gaziers russo-ukrainiens? Cet article soutient que, pour répondre à cette question, il faut synthétiser deux grandes théories des relations internationales (RI) : le modèle de négociation de guerre et la théorie de l'action. L'article applique ces cadres théoriques à la crise du gaz de 2008-2009 entre l'Ukraine et la Russie, en se basant sur des études de cas qualitatives. Les relations gazières bilatérales peuvent être modélisées comme des interactions de négociation de crise - jusqu'à un certain point. La Russie et l'Ukraine ont tous deux recours à des pratiques de négociation de crise pour …  Lire la suite

L'émergence de systèmes de communication hors-ligne de cinquième génération (5G) témoigne de l'utilisation croissante des systèmes MIMO massifs. Lorsque l'on compare le standard de quatrième génération (4G) qui utilise MIMO, on remarque que l'implémentation de systèmes à grande quantité d'antennes offre plus de degrés de liberté. Cependant, les systèmes de 4G atteignent rapidement leur limite en performance et l'augmentation constante d'utilisateurs les rendra obsolètes dans les prochaines années. Les systèmes MIMO massifs donnent la possibilité d'avoir des liaisons avec plus de vitesse, de capacité et de fiabilité. Néanmoins, comme dans le case MIMO, la connaissance de canal affecte directement la …  Lire la suite

The first major contribution to the theory of electrolytic conductivity was made by Kohlrausch (ll) who found that molar conductivity could be expressed as the sum of two quantities - the individual conductances of the anions and cations. He called this the "Law of' Independent Movement of Ions”. The next advance to the theory was made by Arrhenius (13). He assumed that a solution is composed of ions and neutral molecules and that the proportion of ions increased with increasing dilution.  Lire la suite

Laboratory experiments, genetic simulation, and theoretical analyses were performed to address several objectives related to the use of genetic markers in plant breeding programs. Two software packages were developed: GREGOR provides flexible and efficient computer algorithms for performing genetic simulation experiments, and KIN provides improved methods for estimating coancestry from known pedigrees. Random amplified polymorphic DNA (RAPD) markers were investigated in elite barley lines, and estimates of genetic distance based on RAPD markers were compared to estimates based on coancestry. Both types of estimate can provide information that is useful to breeders and geneticists. Genetic simulation was used to investigate …  Lire la suite

Dickson, B. (Supervisors)  Lire la suite

A bicyclic thioglycolate lactam chiral auxiliary was previously developed in our group for the asymmetric formation of quaternary carbon stereocenters via enolate alkylation. This method is notable for the stereocontrolled generation of alpha, alpha-disubstituted amide enolates, without reliance on the steric differences of the alpha-substituents. Coupled with excellent facial discrimination in electrophilic approach, this led to a general and practical method for enantioselective preparation of quaternary carbon centers via alkylation reactions. This thesis describes the extension of this methodology to the stereoselective formation of alpha, alpha-disubstituted beta-amino carbonyl compounds via the Mannich reaction and also the application of the alkylation …  Lire la suite

De nombreuses études ont montré que les granitoïdes de type A sont enrichis en éléments à fort champ ionique (HFSE) tels que les éléments de terres rares (ÉTR), le Zr et le Nb. En revanche, leur potentiel d’enrichissement en scandium demeure mal compris et peu exploré. Le complexe syénitique de Crater Lake, situé dans le nord du Québec, au Canada, constitue le premier gisement de scandium à affinité de type A documenté en Amérique du Nord, et potentiellement dans le monde. Le complexe contient des ressources de 16,3 Mt à 278 ppm Sc₂O₃ dans la catégorie indiquée, et présente les …  Lire la suite

During the last few years, G.W.H. Norman of the Department of Mines and Resources, Mines and Geology Branch, Ottawa, mapped in detail an area extending from Malartic on the west to Louvicourt Township on the east. This work yielded so much information, and prospecting was so extensive in this area, that the Geological Survey extended the work eastward from Norman’s sheet. Three parties were organized in 1946 each to map one township at a scale of 1000 feet to one inch. One party under H.C. Norman mapped Vauquelin Township, the writer mapped Pershing Township, and the third party under K. …  Lire la suite

Nathan Hall (Supervisor1)  Lire la suite

Brain deposition of the $ beta$-amyloid protein is an early marker of Alzheimer's disease (AD). AD is a neurodegenerative disorder characterized by learning and memory impairments. Here, mice (B6C3, 8 and 20 months old) transgenic for a human $ beta$-amyloid fragment were compared to normal litter mates in spatial and non-spatial learning tasks in the Morris water maze, according to standard procedures. Four measures of learning and performance were analyzed statistically: latency, total distance swam, mean distance to a platform, and number of trials correct in reaching a platform. Transgenic mice were impaired relative to their litter mates in spatial …  Lire la suite

Declarative learning entails the internalization of facts and events. This type of learning depends on the integrity of the hippocampal system. In rodents, spatial learning is studied as a model of declarative learning. In this thesis, electrophysiological and behavioral experiments assessed the role of NMDA receptors in synaptic plasticity and rats' spatial learning and memory. Primed burst potentiation (PBP), a form of synaptic strengthening, was studied in freely-behaving rats treated with NMDA receptor antagonists. The impairments caused by the antagonists correlated with those observed in behavioral studies. The results support the idea that NMDA receptors in the hippocampal system mediate …  Lire la suite

Bone-restricted-IFITM-like (BRIL) est une protéine transmembranaire de 132 acides aminés exprimée presque exclusivement dans les ostéoblastes. L’expression de BRIL favorise la minéralisation in vitro, mais sa fonction a été jugée non essentielle in vivo. Les mutations dans la séquence de BRIL sont responsables pour deux formes d'ostéogenèse imparfaite (OI), qui sont héritées de manière autosomique dominante. Le premier est l’OI de type V, provoqué par une mutation 5’-UTR c.-14C>T, qui introduit un site d’initiation de la traduction en amont et code pour les acides aminés « MALEP ». La deuxième forme est l’OI atypique de type VI et est causée …  Lire la suite

La fonction cardiaque repose sur une boucle intégrée d'activité électrique, de signalisation calcique et de contraction mécanique. Pourtant, la plupart des études in vitro continuent de traiter ces processus de manière isolée, limitant notre capacité à modéliser et comprendre des phénomènes clés comme la rétroaction mécano-électrique. Cette thèse s'attaque à ce défi en étudiant comment la rigidité du substrat et les signaux mécaniques influencent le comportement électromécanique des cardiomyocytes humains dérivés de cellules souches iPSC et des fibroblastes cardiaques.La thèse commence par une revue complète de la mécanobiologie cardiaque, mettant l'accent sur l'interaction entre la rigidité et le couplage excitation-contraction …  Lire la suite

Over the last years, important advances have been made in developing in-vitro models of different biological conditions. This has significantly contributed to our understanding of how biological systems interact with their environment, how they respond to their changes and how we can engineer this interaction. Polymeric substrates with tunable stiffness have played a major role in this end. These polymers can mimic various in-vivo conditions, at least from the mechanical point of view, and provide us with the opportunity to get one step closer to what actually happens in our body. However, many in-vivo conditions are dynamic and their mechanics …  Lire la suite

Stringer, Ronald William (Supervisor1)  Lire la suite

Vibrotactile feedback - a type of haptic feedback, is a popular area of research. Aside from widespread applications in video games and mobile phones, vibrotactile feedback is also implemented in Digital Music Instruments (DMIs) to improve the quality of interaction for performers, or as general-purpose interfaces for conducting experimental research. Musical interaction is known to involve high cognitive expertise, requiring responsive and highly accurate tools. When implementing such devices, the outputs of the vibrotactile implementations are characterized and equalized. However, these implementations are often “one-of-a-kind”, bulky (>8 kg), expensive (<1000 $), and impractical to some musical applications, whereas, inexpensive and …  Lire la suite

Mitchell, Denis (Supervisor1)  Lire la suite

The behaviour of captive mallards (Anas platyrhynchos) and black ducks (Anas rubripes) was studied from the end of March to mid-June in 1991 and 1992 to determine the extent of interspecific aggression exhibited and the effect of sympatry and allopatry on interactions between the two species. Mallards were more aggressive than black ducks regardless of sex and origin, though both species were equally attacked in both years, male ducks were more aggressive and more attacked than female ducks regardless of species and origin in both years, and ducks of sympatric origin were more aggressive than ducks of allopatric origin in …  Lire la suite

Tissue-cultured shoots and plantlets usually have leaves with non-functional, open stomata and little epicuticular and cuticular wax, resulting in excess evapotranspiration after transplantation. Various strategies were evaluated to decrease ex vitro acclimatization difficulties for 'Silvan' blackberry, including transplanting unrooted shoots, increasing the medium agar concentration from 6 to 9 or 12 g/l and diluting the basal medium. Increased medium agar concentrations and medium dilution did not improve survival or growth. Stomatal function resumed sooner in new leaves of plantlets than shoots. High relative humidity ($>$95%) and low light intensity (90 $ mu$mol s$ sp{-1}$ m$ sp{-2}$) negatively affected stomatal closure …  Lire la suite

Choksi, Rustum (Supervisor1)  Lire la suite

Our objectives were to measure concentrations of glucose, insulin, insulin-like-growth-factor-binding-protein-1 (IGF BP1) and beta-hydroxybutyrate (BOHB) in amniotic fluid (AF), and establish if these concentrations were associated with emergence of maternal gestational diabetes mellitus (GDM). AF samples (n=408) were collected following routine amniocentesis (12-22 weeks gestation). Glucose and insulin concentrations were elevated in our GDM mother-infant pairs, where GDM was associated with a 176g increase in birth weight. Logistic regression showed that AF glucose but not insulin was associated with developing GDM. Non-linear Bayesian probability plots showed that when 2nd trimester glucose was plotted against insulin increases in both were predictive …  Lire la suite

Riches, Caroline Joan (Supervisor1)  Lire la suite

The need for the development of rigorous analytical models of the knee joint to clarify the role of mechanical factors in joint disorders such as that caused by meniscal tears, long been recognized. In response to this need, a general three dimensional nonlinear finite element model has been developed as part of this work and has been applied to the investigation of the meniscal responses when the joint itself is subjected to 3D complex loading. The geometry of the model has been obtained from the results of in vitro measurements performed on three adult human knee specimens. The method of …  Lire la suite

With a generally conserved function for locomotion, paired fins have an extensive evolutionary history that has resulted in highly disparate morphologies in a wide diversity of taxa. Two-dimensional geometric morphometrics offers a means to quantitatively describe disparity and changes in the shape of pectoral fins. Actinopterygians lend themselves well to a study of this nature due to their prolific diversity and prevalence in the fossil record. As a result of changes in skeletal fin structures and the lack of homologous elements throughout the group, three morphological modules are used as the unit of comparison rather than individual elements of the …  Lire la suite

Cette étude examine les connaissances incarnées de femmes âgées entre 20 et 25 ans, concernant leurs expériences vécues dans leurs relations sexuelles et amoureuses, ainsi que leurs expériences avec une éducation sexuelle formelle et informelle. Les participantes à cette étude étaient sept jeunes femmes qui ont fréquenté l'école secondaire en Ontario et qui ont obtenu leur diplôme entre 2011 et 2015. Les participantes venaient de différentes régions de la province et toutes, sauf une, fréquentaient l'école publique. Cette recherche donne aux participantes l'occasion de faire le lien entre leur éducation et leurs expériences vécues dans leurs relations. Les méthodologies utilisées …  Lire la suite

Human, Jacqueline (Supervisor2)  Lire la suite

À l'heure actuelle, aucun article ne décrit une analyse cinématique du comportement du pied et de la cheville lors de la course sur terrain en pente transversale. Le principal objectifs de cette étude était d'évaluer l'effet d'une pente transversale de dix degrés sur les variables cinématiques au niveau du pied durant une activité de course. Un modèle représentant le pied en trois segments a permis d'évaluer l'exursion angulaire des segments adjacents dans les trois plans de l'espace. Dix coureurs masculins ont participé à cette expérience et ont couru pieds nuds à vitesse modérée pour réaliser les répétitions. L'analyse statistique a …  Lire la suite

Mean seasonal cross-sections along 80 degrees west were constructed from daily analysed data. By this procedure it was possible to formulate means and standard deviations with respect to various jet stream cores and selected temperatures as well as the usual geographical means. A set of such sections for the period June 1959 - May 1960 is presented and discussed.  Lire la suite

La démence de la maladie d'Alzheimer (MA) se caractérise par l'accumulation de plaques amyloïdes-β (A), d'enchevêtrements neurofibrillaires (T) et de neurodégénérescence (N). Elle serait une combinaison de processus pathologiques commençant des années avant l'apparition des symptômes cognitifs, avec l'accumulation d'amyloïde-β provoquant l'accumulation d'enchevêtrements neurofibrillaires, déclenchant à son tour la neurodégénérescence pour finalement aboutir aux symptômes cognitifs. Le diagnostic clinique chez les personnes vivantes est de plus en plus étayé par des biomarqueurs validés cliniquement, qui sont des substituts des changements neuropathologiques susmentionnés de la MA. Les chercheurs ont donc créé une construction biologique permettant l'identification in vivo de la MA …  Lire la suite

This dissertation sets out to determine the social function of paraenesis ("moral exhortation") within Valentinian Christianity. In order to explicate this social function, this study places the discussion within the context of ancient rhetorical practices of ethical admonition; i.e., how did paraenetic discursive practices act as rhetorical devices for affecting social formation? In order to establish the function of paraenesis, it is necessary to engage both literary and social aspects of the paraenetic genre. The latter is most challenging, given the methodological difficulties inherent in moving from textual context to socio-historical reconstruction of the situation behind a text. To address …  Lire la suite

Chang, Xiao-Wen (Internal/Supervisor)  Lire la suite

Accessory hydrogen uptake genes have been identified in a region of the Azotobacter chroococcum genome about 5 kb downstream of the hydrogenase structural genes (hupSL). DNA sequencing has revealed six genes (hupABYCDE) in this region. These genes are probably transcribed in the same direction as hupSL but are probably in a different operon. Mutational analysis had shown that disruption of the hupB, hupY, hupD and hupE genes gives a Hup$ sp-$ phenotype. In the present work additional mutational analysis, using Tn5, a Tn5 -derivative containing a promoterless lacZ gene, and a kanamycin resistance gene, confirms the direction of transcription and …  Lire la suite

This thesis is an examination of the political and educational implications of environmentalism. This movement has been characterized by oversimplifications which have led to confusion about the proper role of humans with respect to the natural world. The modern world system was founded on the concept of human domination of nature, and this led to degradation of both the natural and the social environment. The radical ecological response to this view rejected any role for human subjects other than protection, and called for a rejection of technology and a return to pre-modern conditions. This investigation proposes that citizens in a …  Lire la suite

La mentalisation, ou le raisonnement sur les états mentaux des autres, est un processus cognitif social dynamique qui aide à comprendre des autres. La nature dynamique de la mentalisation découle de sa capacité à s'étendre suite à l'exposition à des perspectives diverses et à des contextes socialement différents, tels que les contextes bilingues. En effet, les individus bilingues obtiennent de meilleurs résultats que les individus unilingues dans les tâches basées sur la mentalisation, et l'exposition environnementale au bilinguisme renforce également la mentalisation chez les enfants unilingues. Cependant, si l'exposition à diverses perspectives par le biais du bilinguisme renforce la mentalisation …  Lire la suite

Heiningen, A. R. P. Van (Supervisor)  Lire la suite

Depuis 20ans, on observe l'intensification des entreprises porcines et la concentration régionale de la production de fumier. Cette concentration a engendré des problèmes de qualité d'eau et de sol, ainsi que de contamination de l'air par les odeurs. Comme solution, la zéolite pourrait être ajoutée à la ration des porcs pour améliorer l'ingestion des nutriments et réduire l'effet de concentration des fumiers. Dans ce contexte, deux essais furent réalisés pour mesurer l'impact d'ajouter de la zéolite dans les rations pour porcs à l'engraissement : le premier visait les propriétés physico-chimiques des fumiers, et ; le second visait la productivité porcine. …  Lire la suite

Depuis plus d'un demi siècle, la transition de la phase métallique vers la phase isolante du dioxyde de Vanadium a captivé les physiciens du solide. Dans sa phase haute température, VO2 est métallique, avec une structure cristalline tetragonale rutile. Dans sa phase basse température, le matériau possède des propriétés eléctroniques de semi-conducteur correlé ainsi qu'une structure de réseau monoclinique similaire à une onde de densité de charge.La détermination de l'influence des intéractions électrons-électrons et électrons-phonons sur la structure électronique de la phase à basse température est à l'orignine de l'inérêt de la communauté pour ce matériau.Au cours des deux dernières …  Lire la suite

Coish, William (Supervisor2)  Lire la suite

Jonathan Le Roy Sievers (Supervisor)  Lire la suite

This thesis describes the development of new palladium and nickel catalyzed carbonylation reactions to efficiently and rapidly generate products with minimal waste. These reactions can be carried out using commercially and/or readily available starting materials, including imines, acid chlorides, aryl iodides, alkynes, alkenes and carbon monoxide. In chapter 2, we describe a palladium catalyzed carbonylative synthesis of polysubstituted imidazoles. This transformation involves a tandem catalytic process, where a single palladium catalyst mediates both the carbonylation of aryl halides to form acid chlorides, as well as cyclocarbonylation of -chloroamides, to generate 1,3-dipoles. Finally, a regioselective 1,3-dipolar cycloaddition with electron poor imines …  Lire la suite

The Alfred Bog wetland is the largest high quality bog ecosystem and one of the most important natural areas in southern Ontario. The 4,200 hectare bog provides habitat to a large number of rare and endangered species and plays an integral role as a natural water filter. This study used the contingent valuation survey method to estimate respondents' willingness to pay for the preservation of the Alfred Bog wetland, which is threatened by the competing activities of drainage, burning, and the extraction of peat. A multiple bounded discrete choice model was used to analyze the survey results. Results indicated that …  Lire la suite

The objective of this dissertation is to ascertain empirically whether there are non-linearities between interest rates and selected macroeconomic variables in the monetary policy transmission mechanism. This is accomplished by using recently-developed econometric techniques to uncover, and model, the non-linearities. We consider relationships between five variables along the path of the transmission mechanism (commercial interest rates, consumption, investment, output growth and inflation changes) and interest rates over which the central monetary authority has significant control (such as a long-short yield spread or a short-term money market rate). Our findings reveal that there is evidence in favor of non-linearities, with expansionary …  Lire la suite

Olga Huk-Papanastasiou (Internal/Cosupervisor2)  Lire la suite