McGill University Thèses et mémoires par auteur commençant par T

A method is given for applying one-dimensional analysis to an injector with constant diameter mixing. A review is made of the theory for the turbulent mixing of air streams. Some of the difficulties of applying this theory to injectors are considered. An outline of experimental work is given for a simple air injector with constant diameter mixing at low temperatures. In this injector a single convergent type primary nozzle was used operating at higher than critical pressure ratios.  Lire la suite

Contained within the parameters of postmodern thought, particularly feminist critical perspectives on western epistemology, this thesis proceeds from the following arguments: that knowledge is political: that it possesses a reflexive and dialectical nature and that it is based upon interpretations of reality which are in potential, indeterminate in range. Within these boundaries, knowledge is viewed as a phenomenon subject to influence from social power structures. And western culture is observed to breed situations of epistemological inequality where knowers may become unjustly privileged or oppressed. Focusing on arguments expounded by Lorraine Code, Patti Lather and Catherine Walsh, this thesis aims to …  Lire la suite

This thesis offers Plato's readers a different approach to reading the Gorgias. Chief consideration is given to Plato's artistic plan as a rhetorician, rather than a strict moral philosopher. The display of his rhetorical genius works to support his arguments in favour of a certain kind of rhetoric. The usual argument that Plato is attacking rhetoric is rejected here. In its place the reader will see a Plato refuting his contemporaries' spurious form of rhetoric, as the rhetoric Plato represents and displays is a true craft, as genuine as the dialectic. Rhetoric is not without its shortcomings, but neither is …  Lire la suite

Through the 137Cs mass balance method, annual consumption rates were estimated for juvenile Atlantic salmon parr and precocious males, as well as brook trout from 4 sites within the Ste Marguerite river system, Quebec. With explicit age analysis, feeding rates and growth rates were derived on an individual fish and age class basis. These represent the first consumption estimates for Atlantic salmon in the wild. The individual fish approach provided a range of data for a single site, as opposed to a single estimate per age class, allowing for an evaluation of the relationship between consumption and growth for each …  Lire la suite

Eggs of many organisms contain a store of mRNA which supports protein synthesis during early embryonic development and various regions of the egg cytoplasm are not identical with respect to developmental potential. I investigated the extent to which sea urchin embryogenesis results from a progression of developmental events directed by the embryo, or an expression of a pre-formed maternal program. By the use of two-dimensional electrophoresis I demonstrated that cellular determination during embryonic development at the 16-cell stage is not accompanied by qualitative changes in the distribution within the embryo of abundantly-synthesized proteins, virtually all of which are coded by …  Lire la suite

Classical models of differentiation assume that cell fate is determined by the concentration of a static morphogen gradient. In contrast, we provide a setup for in silico differentiation and patterning of embryos under the action of a temporal morphogen signal. We analyze a simplified model for neural tube patterning and use dynamical system theory to uncover the emergence of a slow timescale due to a saddle-node bifurcation. Using the theory of slow manifolds, we give an analytic solution for the canalization of gene expression in phase space. We generalize the patterning mechanism and find gene networks with higher number of …  Lire la suite

During the process of neuronal lamination, the developing nervous system must provide newly born neurons with precise instructions for their final destination. The decision of where to place a cell body is essential to the formation of appropriate synapses and to the function of the mature circuit. Whether, and precisely how, early life experiences in the form of activity in the developing circuit influence neuronal lamination remains unexplored. Using the mammalian retina as a model for the emergence of a highly laminated structure, we showed that light- evoked activity during development acts in a cell-extrinsic manner to control the lamination …  Lire la suite

This thesis is a discussion of the origin of the chert in the Ordovician limestone of the Saint Lawrence lowlands. The chert is dark grey to black in colour. It occurs as beds and variously shaped nodules, and in one outcrop, as vein-like or dyke-like tabular masses. The chert appears at three different horizons. At the base of the Beekmantown group, the top of the Black River group, and near to the base of the Trenton group.  Lire la suite

L'éthologie de kwashiorkor, une forme de malnutrition severe et aigu chez les enfants, peut-etre lié a l'inflammation et le stress oxydatif. La biodiversité peux contribuer des propriétés qui favorise la santé et qui adresse l'inflammation et le stress oxydatif qui se trouve dans le kwashiorkor. Six plantes medicinal, cinq légumes à feuilles vertes et deux fruits sauvages ont été recueillis par Kaiti Division, Makueni County, Eastern Province, Kenya et examiné pour des propriétés antioxydant et anti-inflammatoire en utilisant les dosages ORAC et des phénols totaux et un dosage TNF- α in vitro, respectivement. Tous les plantes médicinales et plusieurs LGV …  Lire la suite

This thesis investigates the importance of forest products for Hmong highland minorities in Sa Pa district, Lao Cai province, northern Vietnam. Since their migration from Yunnan nearly two centuries ago, the Hmong in upland Vietnam have remained relatively autonomous, relying on a diverse production system including wet rice terraces, swidden fields, livestock, non-timber forest products and, more recently, for a limited number, handicraft and tourist-related activities. In 1992, the Vietnamese Government, via Decree 327, officially banned all forms of slash-and-burn practices and opium cultivation, thus cutting off highlanders from important sources of income. Drawing on qualitative field work, I examine …  Lire la suite

The importance of host factors in determining susceptibility to systemic Candida albicans infections is evident in both humans and mice. We have used a mouse model to study the genetic basis of susceptibility, using the inbred strains A/J and C57BL/6J, which are susceptible and resistant to infection, respectively, based on different parameters of response to infection. To identify genes responsible for this differential host response, brain and kidney fungal load were measured in 128 [A/J x C57BL/6J]F 2 mice 48 hours after infection with 5x104 C. albicans blastospores. Segregation analysis in this informative population identified complement component 5 (C5/Hc) as …  Lire la suite

The potential of dielectric heating with microwaves at 2450 MHz for drying grapes into raisins was studied. Feasibility studies in a conventional microwave oven were successful. A new microwave drying system equipped with specialized instrumentation and data acquisition components and permitting full control of microwave power levels and duration of application was then developed and used for detailed experimental work. It was found that when the grapes were dipped in surfactants, as is common practice in the raisin industry, microwave drying was not only faster than convective drying but also had a much lower specific energy requirement. However, it was …  Lire la suite

The geographical location of the Island of Montreal, where the St. Lawrence River meets the Ottawa, is perhaps the most significant factor contributing to Montreal’s commercial importance. Geology has assisted in making Montreal an entrepot between the Atlantic and the St. Lawrence - Great Lakes hinterland. The Sault St. Louis or Lachine Rapids, at the south-west corner of the island, are composed of extremely hard rock which resists the erosive character of the river. The Lachine Rapids are turbulent and dangerous, so that the port of Montreal at the foot of them is the farthest point accessible to ships ascending …  Lire la suite

Molecular self-assembly (MSA) was used to fabricate multilayered composites on silicon, silicon monoxide and silica substrates. 3-mercaptopropyltrimethoxysilane (MPTMS) was grafted onto the substrates, followed by chemisorbed silver colloidal nanoparticles. 1,4-benzenedimethanethiol (BDMT) was used to chemisorb gold to silver colloidal nanoparticles forming an MPTMS-silver-methyl-BDMT-gold heterostructure. A self-poling stilbazole dye---(E)-[4- N,N-(octadecylmethylamino)styryl]pyridine (ODMASP)---was integrated with a mercaptoacetic acid (MAA) spacer into an MPTMS-silver-MAA-ODMASP heterostructure by MSA of ODMASP C18 alkyl tails. ODMASP on fractal silver aggregates enhanced the 2nd-order nonlinear susceptibility implying that silver colloid intensified the electrical field to produce a c2 of 1.48 x 10-22 C3/J 2 (4.00 x 10-8 esu). …  Lire la suite

The challenge in measuring and training attention is demonstrated by the cognitive construct’s divergent definitions and hierarchical nature. This program of research argues that a measure of an individual’s ability to complete everyday tasks and learning capability can serve as a functional assessment of attention. Specifically, Attention Resource Capacity (ARC), or an individual’s capability to allocate attentional resources from their limited reserve to relevant information while suppressing the allocation of resources to irrelevant information, is typically associated with competency. Thus, the foundation of this dissertation is based on repurposing the traditional Multiple Object-Tracking (MOT) paradigm to (i) characterize the attention-learning …  Lire la suite

This study explored the limits of distributed attention using a three-dimensional multiple object-tracking paradigm (3D-MOT), a measure of dynamic, distributed, sustained and selective attention. Traditional MOT studies have for the most part used two-dimensional paradigms that lack object occlusion, object collision, and do not present objects in depth. The inclusion of these three components represented in everyday vision provides a better balance between empirical and ecological measures of tracking multiple objects. The limits of distributed attention were explored through the manipulation of the task’s cognitive load (task difficulty) by varying the number of target items. Furthermore, the integration of feedback …  Lire la suite

Synucleinopathies, such Parkinson's disease (PD), like all neurodegenerative disorders, present a significant health burden globally. Synucleinopathies manifest with a spectrum of motor, as well as non-motor symptoms, attributed to the accumulation of misfolded alpha-synuclein (aSyn) protein first observed postmortem in the brains of suffering patients. However, the exact mechanisms underlying brain atrophy and disease progression remain elusive, but evidence suggests aSyn spreads in a prion-like manner throughout the brain, contributing to the Lewy pathology in the brain. Despite these advancements in understanding aSyn spreading, its translation to atrophy and clinical symptoms remains unclear. This thesis investigates the hypothesized prion-like aSyn …  Lire la suite

The subcortical structures of the brain, such as the striatum and thalamus, are positioned deep within the brain and are heavily implicated in the regulation of mood, reward, and memory function. Further, these structures are heavily connected to the frontal lobes of the brain, which include regions that are implicated in complex cognitive tasks. Despite their importance in daily functioning and implication in neuropsychiatric disorders (such as schizophrenia and geriatric depression) and in movement disorders (such as Parkinson's disease and Huntington's diseases), these regions are under-studied, in part due to the paucity of methods available for accurate visualization and extensive …  Lire la suite

This thesis presents the various methods of assessment and repair of damage to concrete bridges. The current repair and replacement techniques are identified and evaluated. Plausible repair-in-place techniques being used presently are reviewed along with the relevant details. Guidance is also provided for inspection and assessment of damage from accidents, fire, design and construction defects, and other causes. Suggested guidelines for damage assessment and for selection of repair methods are presented along with some examples from the existing practice. The repair methods have been evaluated on the basis of load requirements, speed of repairs, durability, relative costs, aesthetics, materials, methods, …  Lire la suite

Cette thèse se consacre à la comparaison de deux romans de science-fiction utopique, Woman on the Edge of Time (1976) et He, She and It (1991) par Marge Piercy et soutient que l’évolution de la vision utopique de l’auteure est emblématique de l’évolution de sa vision politique en tant qu’activiste, romancière et poète. En suivant Ruth Levitas, qui définit l’utopie comme « l’expression du désir pour une meilleure manière d’être », cette thèse analyse la forme, le contenu et la fonction des utopies de Piercy en comparant le déplacement spatial et temporel de leurs lieux utopiques. De plus, cette thèse …  Lire la suite

With the development of free-economy relations and with the changes in the social life of Russia that continue to this day, a construction boom in the low-storied housing market, which began in 1991, continues. However, despite the rapid development of the low-storied market itself, the construction industry was unable to adapt to the new economic relations and the high consumer demands being placed on it. This led to an increase in prices for low-storied housing and made it unaffordable for most strata of the population. This paper will consider the peculiarities of applying new construction technologies in the market for …  Lire la suite

Oncolytic virus therapy is a new form of cancer treatment that uses viruses that preferentially infect and lyse cancer cells. Vesicular stomatitis virus (VSV) is a strong oncolytic virus candidate that infects multiple tumor cells, produces rapid viral replication in malignant cells and spreads quickly in the tumor. Defects in the interferon (IFN) antiviral pathway are common in tumor cells and such defects are accountable for the sensitivity to VSV infection and replication in several malignant cells. The intrinsic mitochondrial apoptotic pathway plays a crucial role in VSV-induced apoptosis and disturbance of this pathway is responsible for resistance to VSV …  Lire la suite

This thesis examines the symbolic use of space in the trilogy of Giorgio Bassani: Gli occhiali d'oro, Il giardino dei Finzi-Contini and Dietro la porta. All written in the first person, the novels are part of a continuum since in each one the same narrator remembers a different event from his past. All three novels recreate events which took place prior to the Second World War; two make direct reference to the grueling period of antisemitism under the Fascist regime. Through the spatial element we analyze the moral and psychological states of the various characters, in particular of the young …  Lire la suite

Les alliages d'aluminium (AA) sont très demandés dans les secteurs de l'aérospatiale et de l'automobile, principalement en raison de leur résistance spécifique élevée. Les progrès récents dans la fabrication de composants industriels avec des alliages d'aluminium à l'aide de la fabrication additive (AM) ont ouvert de nouvelles voies dans la production de composants ultralégers et des économies considérables de carburant dans le secteur des transports. Le processus de fusion laser sur lit de poudre (LPBF) a permis de fabriquer avec succès des supports et des tuyères pour l'aérospatiale avec une architecture intelligente et des caractéristiques fines. C'est pourquoi l'AM des …  Lire la suite

An understanding of the behaviour of rocks subjected to stress is of great importance in engineering practice. Many large engineering projects utilise rock materials either directly, as part of the structure, or indirectly, as the foundation upon which the structure ,or indirectly, as a function upon which the structure will rest. [...] Amongst others the United States Bureau of Mines (2) (3) (4) and Association of Mine Managers in South Africa (5) have published data relating to the physical properties of quartzites. Some of these data are included for comparative purposes.  Lire la suite

Sarkar, Mekhala (Internal/Supervisor)  Lire la suite

Al powder metallurgy (P/M) offers several advantages over traditional manufacturing methods, such as near-net-shape production and eliminating or reducing material waste. However, the native oxide layer of Al prevents the sintering of Al particles and must be eliminated, but the stable character makes physical means of reducing the layer ineffective. Some strategies to disrupt the oxide layer are liquid phase sintering or forging of sintered compact. Forging is more attractive in terms of near-net-shape processing, as heterogeneous shrinkage that can arise during liquid phase sintering can lead to dimensional inaccuracies. Another alternative, spark plasma sintering (SPS), is a pressure and …  Lire la suite

The Quebec Education Program (QEP) provides educators with detailed descriptions of competencies of learning achievement. However, current approaches used by educators to instruct and assess their students do not target the relevant QEP competencies. The goal of this thesis is to document efforts of one teacher to implement digital portfolios in her grade one and two classroom in order to instruct and assess her students according to the relevant QEP competencies. The study documents the kinds of technology and skills that are needed to implement digital portfolios in order to instruct and to assess and communicate student learning to their …  Lire la suite

Cette étude a pour but d'observer les effets de l'apprentissage autodidacte —en anglais «self-regulated learning» (SRL)— sur les capacités de résolution de problème des élèves en mathématiques. Particulièrement, elle s'adresse à la question de si les élevés peuvent profiter de l'utilisation de l'enregistrement vidéo pour réviser leur propres essais à résoudre des problèmes de mathématiques. 40 élèves de huitième année ont initialement participé à cette étude en résolvant un problème sur le rapport et la distance. Par la suite, les 20 élèves qui étaient incapables de résoudre le problème sont invités à une reprise. À leur deuxième essai, 11 élevés …  Lire la suite

Cette thèse étudie le rôle des cellules souches et progénitrices hématopoïétiques (HSPC) dans la régénération des systèmes sanguin et immunitaire lorsqu'elles sont exposées à un stress génotoxique, à une blessure et à une inflammation chronique. En particulier, nous étudions la réponse au stress des cellules souches et progénitrices hématopoïétiques dans le contexte du stress génotoxique et des maladies inflammatoires auto-immunes. La première partie de la thèse explore la réponse des HSPC à l'irradiation du corps entier chez la souris. En utilisant p53 ChIP-Seq et des souris p53-knockout, notre étude a révélé de nouveaux gènes régulés par p53 et a examiné …  Lire la suite

The stretch reflex is an involuntary contraction produced in response to muscle stretch. Despite extensive research, its role in the control of movement and posture remains controversial. One reason for this is that the torque output produced by reflex activity has been studied in only a limited number of tasks and behaviours. The main thrust of this thesis is to examine whether the central nervous system (CNS) modifies stretch reflex properties to suit the task. An electro-hydraulic actuator applied perturbations to the ankles of five subjects while they performed position-matching (PM) and torque-matching (TM) tasks. Stretch reflex properties were determined …  Lire la suite

In recent years the development of radio communication and of allied techniques such as radar and television has involved the use of higher and higher frequency signals. This trend has arisen, either from the need of more channels in the useful frequency spectrum, or, as in radar, from the need of directional antenna systems of reasonable size. In tubes of conventional design the upper limit of the useful frequency range is set by considerations of transit time of electrons, radiation losses and inductance of leads.  Lire la suite

The mathematical technique of dynamic programming may be used to determine the control function which will optimize the performance of a system with respect to some given performance criterion. To illustrate this, the optimal control function for a second order system was calculated, subject to constraints on the state variable es as well as the control function. [...]  Lire la suite

Here I compare the temporal characteristics and processing of binaural cues for sound localization in the auditory sensory neuron ON 1. I compare the ability to produce cues for sound localization in two field cricket species (Teleogryllus oceanicus and Gryllus texensis) with highly different calling songs. G. texensis has a trilling calling song with a pulse rate of 78 pulses per second. T. oceanicus has a more complex calling song with a behaviourally relevant pulse rate of 16 pulses per second. By using information theory, I found that ON 1 in G. texensis is able to code amplitude modulation frequencies …  Lire la suite

Studies of the phenomenon of language acquisition conducted prior to 1950 were mainly theoretical in nature and dealt alomost exclusively with the acquisition of the primary or native language in the young child (40). Subsequent to 1950, an increasing amount of experimental research has been devoted to language acquisition. [...]  Lire la suite

An empirical rule which predicts which enantiomer will be preferred by lipases (triacylglycerol hydrolases) based on the relative sizes of the substituents has previously been developed for secondary alcohols. This rule was then extended towards primary alcohols for lipase from Pseudomonas cepacia (PCL). However, the rule for primary alcohols shows an opposite enantiopreference compared to the rule for secondary alcohols. Furthermore, it is no longer valid when an oxygen lies at the stereocentre. This thesis explores the molecular basis for the empirical rule for primary alcohols and why the rule is no longer valid when an oxygen lies next to …  Lire la suite

A reinforced concrete ductile flexural wall requires the placement of well-detailed concentrated reinforcement at the ends of the wall. This often results in congestion in these heavily reinforced regions, resulting in labourious construction. Two flexural wall specimens, containing structural steel boundary elements, were constructed and tested under reversed cyclic loading to evaluate the performance of this new construction technique. For comparison, a third wall specimen meeting the requirements of a standard reinforced concrete ductile flexural wall was constructed and tested under reversed cyclic loading. One of the composite walls used rectangular hollow structural sections (HSS) as boundary elements which were …  Lire la suite

This dissertation addresses the roles that Armenian, French, and Russian musicians and music scholars played in shaping ideas about “authentic” Armenian music during the fin-de-siècle (1880s to the 1920s). I argue that their efforts, which involved analyzing and repositioning Armenian folk music, resulted in codifying what many may recognize today as Armenian art music. Their work unfolded in specific homeland and diaspora contexts. Both Armenians and non-Armenians in the group were motivated by the concept of national music in the final decades of the Ottoman and Russian Empires (respectively dissolving in 1922 and 1917). Given the Armenian nation’s geographical proximity …  Lire la suite

The key to understanding Islam and civil society is the state. However, this key issue has been decentered due to the prevailing focus in the literature, that is the compatibility/incompatibility between Islam and civil society. The findings of this thesis reveal emergent Islamic sensibilities and capacities that lead to transitions in state-Islam interaction. These findings call for a rethinking of the theories on civil society and Islam. The study is based on an extended empirical research project undertaken in Turkey and Kazakhstan between 1997--1999. It focuses on the leading Islamic community-movement in Turkey, Gulen Community, which is not only national(ist) …  Lire la suite

The subject of this thesis is the production of electromagnetic radiations during relativistic heavy ions collisions. Since they constitute one of the major ways to probe the presence of a quark-gluon plasma (QGP), their evaluation through theoretical models is very important. The photon production at low-to intermediate transverse momentum (pT) is first studied. The photon production rate in a mesonic gas is evaluated within a massive Yang-Mills (MYM) approach. Earlier calculations are reexamined with additional constraints, including new production channels and with the inclusion of form-factors. Adding primordial N-N contribution and existing baryonic and QGP production rates, we can reproduce …  Lire la suite

Moodie, Erica (Supervisor1)  Lire la suite