McGill University Thèses et mémoires par auteur commençant par É

Un lecteur au courant des oeuvres essentielles de la littérature française ne laisserait pas entrevoir une lacune considérable dans ses connaissances, s'il demandait en lisant le sujet de cette thèse, qui est Pierre de Coulevain et à quel titre mérite-t-elle une étude approfondie de ses oeuvres? Il est vrai que très peu de place lui est accordée dans la critique littéraire de son pays. Il a fallu môme des recherches opiniâtres pour établir la date exacte et le lieu de sa naissance.[...]  Read more

We show that all fundamental barriers to simulations of various supersymmetric field theories in 3 and 4 dimensions with a lattice regulator can be removed with known and established methods and provide detailed procedures to accomplish this end for N=1 Super-Yang-Mills theory in 3 dimensions and N=4 Super-Yang-Mills theory in 4 dimensions. We also describe generalizations to various other 3 and 4D theories with varying levels of detail where appropriate and analyze a novel new approach to lattice supersymmetry: discretization of a particular topological twist of Super-Yang-Mills in 2 and 4 dimensions.  Read more

We show how 3-dimensional, N=2 supersymmetric theories, including super QCD with matter fields, can be put on the lattice with existing techniques, in a way which will recover supersymmetry in the small lattice spacing limit, with O(a) lattice spacing suppressed SUSY breaking effects.  Read more

Alters, Brian Josiah (Supervisor2)  Read more

Mcintosh, D. (Supervisors)  Read more

Unravelling the complexities of biological communities has long interested community ecologists. Molecular, computational and conceptual advances in the last fifteen years have led to the increasing incorporation of phylogenetic information into ecological analyses, creating a new field of 'community phylogenetics'. Although the field of community phylogenetics has improved our understanding of the processes determining community composition, more recently the field has been challenged because of its reliance on several critical assumptions. In this thesis, I address some of these critiques by exploring novel empirical and analytical approaches. In Chapter 2, I describe the major challenges to sampling a comprehensive species …  Read more

This study explores the nature of teachers' understandings of theoretical orientation to reading and the relationships between theoretical orientations to reading and instructional practice. The participants were eleven Grade Five classroom teachers, seven female and four male, in one particular school board in Southern Ontario. A series of three in-depth, phenomenological interviews were conducted with each teacher-participant. Utilizing the concept of theoretical orientation to reading, understandings of and relationships between, theoretical orientation to reading and instructional practice were identified and described by the teachers in this study, from an 'emic' (insider) perspective. The themes of teachers' knowledge and beliefs, personal …  Read more

The paradox of tropical forests is that they are simultaneously the most diverse, the least understood, and the most imperiled terrestrial ecosystem in the world. Dramatic increases in the atmospheric carbon dioxide (CO$ sb2$) concentration threaten to adversely affect fundamental climatic and ecosystem processes, gradually changing many things which we do not yet understand. Although the impacts of this rise have been studied in temperate areas, little research has investigated tree responses in the tropics, especially under natural frost conditions. This thesis examines three central issues in tropical ecophysiology and global change. First, it investigates the feasibility of in-situ measurements …  Read more

Evidence to show that rusted wheat can fix elementary nitrogen was reported by d'Oliveira in 1939. If this be true the infection of this host by this parasite would have the rare property of fixing nitrogen in common with mycorrhiza, leguminous plants infected with root nodule bacteria and the few other possible associations. The fact that there is a short initial mutualistic symbiosis between rust and wheat makes this possibility of nitrogen fixation by the rusted wheat not entirely unlikely. However, d'0liveira's studies were admittedly preliminary ones, in which he used the Kjeldahl method of nitrogen analysis. [...]  Read more

The- present study aims to discover the theological content and background of the term logos as used in the Prologue to the Fourth Gospel. The use of the term was traced through primary sources of possible influence on the Evangelist,-on the Greek side, the fragments of Heracelitus, Plato, Aristotle, and the Iiterary remains of the Stoics from Zeno through Cleanthes. A study was also made of certain key concepts in the mythological tradition.  Read more

Factors responsible for variable results in small chamber fumigation tests were studied to develop a reliable and sensitive method for detecting susceptibility differences between insect strains. Quart Mason jars; weighed fumigant-filled glass capillary tubes; absorbent paper; and screen cages attached under jar lids and charged with insects through readily sealed openings constituted the apparatus selected. At room temperature a two-hour evaporation period, five-hour exposure period and 14- to 20-day post-exposure period proved best. The effects of day-to-day variability were minimized by testing each material along with a standard and making comparisons based on susceptibility indices. [...]  Read more

Although 70 years have passed since Friedrich Miescher made this statement it is only during the last two decades that the full significance of the fundamental and central role of phosphorus in biological systems has been recognized. The presence of phosphorus as a key constituent in biological substances was first noted by Liebig (2) who isolated from marnma1ian muscle a crystalline material which was subsequently identified as inosinic acid. With the isolation during the present century of other naturally occurring phosphate esters, it has become apparent that phosphorylated compounds are invariably associated with the production of chemical energy.  Read more

Adams, Frank Dawson, 1859-1942 (Supervisors)  Read more

There have been many attempts to measure the crop of animals on the sea bottom in north European waters, where large numbers of benthonic species are economically important as stocks of food for commercial fish. Although the methods have also been applied to a few arctic localities (see page 8), very little is known about the size of the crop in the vast region between Greenland and the Pacific coast of Alaska. Quantitative surveys of the marine benthos were therefore made in Baffin Island during 1954 and 1955 and in West Greenland during 1956 in order to estimate the standing …  Read more

In 1817 - 78 the Howgate Polar expedition wintered in Cumberland Sound, Baffin Island, at the little harbour of Annanactook. The position of the camp is now uncertain, but it was probably at the head of the Sound, on the east shore, within thirty or forty miles of Pangnirtung. Included in the personnel of the expedition were two scientists, Sherman and Kumlien, who were responsible for the meteorological and biological observations. Kumlien was the first professional biologist to examine the shores of Baffin Island (Kumlien, 1879).  Read more

L'approche de la chaîne de valeur a été appliquée pour améliorer la performance des entreprises au cours des années et récemment dans les chaînes de valeur agroalimentaires. Bien que la production des activités de la chaîne de valeur soit ciblée vers le consommateur, sa satisfaction est largement ignorée dans l'analyse de la chaîne de valeur. Il n'y a pas de cadres qui ont été élaboré pour saisir de manière adéquate le lien entre les chaînes de valeur alimentaires, les préférences des consommateurs et la sécurité alimentaire. Pour combler cette lacune, un cadre méthodologique pour l'analyse de la chaîne de valeur …  Read more

Crop insurance is designed for managing crop production risks through the compensation of farmers in the event of a hazard or crop failure. The continued dependence on rain fed production by farmers increases their vulnerability to risk leading to variability of production and income. Since crop insurance is a risk management tool with the potential of dealing with risk more efficiently, the study uses a dichotomous contingent valuation method to elicit the willingness to pay for crop insurance among cereal farmers in the Eastern region of Ghana. A sequential decision was considered. An initial decision regarding the willingness to purchase …  Read more

This dissertation addresses the impact of principles of soft law on the development of international regimes for environmental protection. It focuses on three such principles that have attracted a certain degree of consensus in international environmental law and are therefore influential in international environmental regimes: namely, the principle of common but differentiated obligations; the principle of common heritage of mankind and its corollary, the principle of common concern of humankind; and the precautionary principle. The regimes analysed are the Antarctic regime, the regime for control of trade in endangered species, the regime for protection of the stratospheric ozone layer, and …  Read more

The methods of overcoming the problem of high diagonal tension stresses in flat plate construction are: (1) to change the building dimensions or the concrete strength or both, (2) to use grillages, (3) to use a reinforcement system made from ordinary reinforcing bars. An increase in the concrete strength is the most economical method but does not permit the diagonal tension stress to be increased by more than 33 percent. The second method is about eight times as costly as the increase in concrete strength and about four times as costly as the third method. The second method has been …  Read more

The processing of sensory signals is an important, yet complex task in which a system must extract behaviorally relevant stimulus patterns from a vast array of sensory cues. When a neuron within a major sensory area is presented with a stimulus, one of the important characteristics used to distinguish between types of input is frequency. Often sensory neurons are tuned to narrow stimulus frequency ranges and are thus charged with the processing of subtypes of sensory signals. The weakly electric fish Apteronotus lepthorhynchus senses it's environment through modulations of a self-generated electric field. Two main types of sensory signals can …  Read more

Whyte, Lyle (Supervisor1)  Read more

This thesis consists of an original translation of three chapters of the early Tantric Buddhist text called the Mañjuśrīmūlakalpa. I argue that the straightforward set of ritual instructions and simple pronouncements of efficacy that the text makes conceals its conceptual and doctrinal complexity. First, I analyse the strategies the text uses to legitimate the practices it teaches, along with the production and iconography of a cloth painting called a paṭa. Then I examine the various components of the ritual including ascetic and preliminary practices, the specified times and locations for carrying out the ritual, offerings and fire oblations, and the …  Read more

The purpose of the present investigation was to demonstrate transformation in the genus Rhizobium, using strains of R. meliloti and R. trifolii as the test organisms. The initial work was directed towards an understanding of the metabolism of these organisms and the selection of stable mutants suitable for use in such a study. Five chloramphenicol-resistant strains of R. trifolii were obtained by a "Crystal Violet-tolerance" technique developed during the course of the present research. Suitably resistant strains of R. meliloti could not be isolated. Streptomycin resistance was subsequently selected for among the chloramphenicol-resistant strains.  Read more

In conclusion, this study has shown that the combined effect of several "barriers" can be used in conjunction with low oxygen modified atmosphere and high barrier packaging films to inhibit or reduce aflatoxin to safe and acceptable levels, particularly at abusive temperatures encountered during storage.  Read more

Walter, H. (Supervisors)  Read more

In this work, we review some of the major steps in the construction of the Laplacian overgeneral self-similar fractal sets, and study properties of its spectrum and eigenfunctions ofthe constructed formulation. After a detailed exposition of self-similar sets and their characterisation, functional analytic and measure-theoretic techniques are used to develop aviable Laplacian over self-similar fractal sets equipped with a regular harmonic structure.An exposition of the properties of eigenfunctions and a Weyl’s-type law is presented forthe corresponding eigenvalues. The work concludes with a discussion of the heat ker-nel, and possible methods of heat kernel embeddings of post-critically finite fractals intoHilbert spaces, …  Read more

Interaction between rigid and flexible track-grouser systems with a clay soil is examined in order to obtain a better understanding of the manner in which energy is transferred and dissipated in the bearing soil substrate. Analytical framework is developed for the establishment of the kind of mechanisms involved in this interaction with a view to obtaining a rational prediction of track-soil performance. The method of visioplasticity is used to determine the specific participants contributing to the expenditure of energy at different soil levels beneath a simple representative multiple grouser element. Subsoil reponse behaviour and dissipated energy components are investigated for …  Read more

Aptamers are single-stranded DNA or RNA oligonucleotides that can fold into tertiary structures, enabling them to bind target molecules with high specificity and selectivity. With advances in solid-phase oligonucleotide synthesis, aptamers have become known for their low-cost production, batch-to-batch reproducibility, and ease of chemical modification. These advantages make them attractive alternatives to antibodies in biotechnology, diagnostics, and therapeutics. However, when compared to their protein counterparts, aptamers face several limitations, including restricted chemical diversity, susceptibility to enzymatic degradation, and rapid biological clearance. To address these challenges, various chemical modifications such as base and sugar modifications, backbone alterations, and end-group functionalization have …  Read more

In combinatorial graph theory, decomposable graphs are such type of graphs that are guaranteed to be decomposable into conditionally independent components, known as maximal cliques. In statistics, decomposable graphs are widely used in the field of graphical models or Bayesian model determination, where the dependency structure among high dimensional data or model parameters is unknown. Decomposable graphs are hence used as functional priors over large covariance matrices or as priors over hierarchies of model parameters. One such example is the Gaussian graphical model (lauritzen 1996, whittaker 2009), which has seen success in a variety of applications. Beyond this framework, decomposable …  Read more

Tolerating and minimizing the overhead of communication/synchronization are crucial for getting good performance on parallel machines. In this thesis we evaluate one of the approaches proposed to achieve this goal. This approach is to provide architectural support, consisting of an extra processor, on every node of a parallel machine. This processor is responsible for communication/synchronization and scheduling threads of computation. As a mean to achieve this, we built a user-level communication/multi-threading package called the Threaded Communication Library (TCL) which provides communication/synchronization primitives for programs running under a multi-threaded program execution model. This library was implemented on the GMD MANNA parallel …  Read more

Les stéréocentres de carbone α-quaternaire sont un motif commun mais difficile rencontré dans la synthèse de nombreuses molécules organiques, allant des produits naturels aux molécules utilisées dans les efforts de chimie médicinale. Ici, des stéréocentres de carbone a-quaternaire cycliques ont été synthétisés à partir de substrats bisélectrophiles et d'un sulfonyl lactame bicyclique chiral facilement préparé. Ceci a été réalisé en deux étapes par spiroalkylation, en utilisant des conditions de réaction biphasique avec un catalyseur de transfert de phase, suivi par une réduction et une alkylation avec une série d'électrophiles d'halogénure d'alkyle. Les produits de cette méthode ont été isolés en …  Read more

The use of cellular networks for massive machine-type communications (mMTC) is attractive due to the availability of existing infrastructure. However, the large number of user equipment (UEs) in mMTC poses significant challenges to the random access channel (RACH), particularly due to congestion and overloading. Existing RACH designs typically assume single-priority systems with uniform preamble selection, in which each UE randomly selects a preamble from a predefined set. To mitigate congestion, schemes such as UE backoff and preamble partitioning have been proposed, which either defer transmissions or assign subsets of preambles to different UE classes. Nonetheless, after the backoff period or …  Read more

Outre la perte d'habitat, les espèces envahissantes constituent l'une des plus grandes menaces pour la biodiversité. Par conséquent, la détection et l'identification précoces des espèces perturbatrices sont essentielles pour la formulation de stratégies de prévention et de gestion. En utilisant l'imagerie hyperspectrale (IHS) aéroportée, une méthodologie a été établie pour identifier et cartographier le roseau Phragmites australis subsp. australis, une espèce envahissante présente à travers le parc national des Îles-de-Boucherville (Montréal, Québec), l'un des cinq sites d'études de l'Observatoire Aéroporté Canadien de la Biodiversité (CABO). Aucune recherche de CABO n'a été menée auparavant pour cartographier les phragmites sur ce site …  Read more

Hamel, C. (Supervisor)  Read more

Increasing levels of nitrate (NO3-) in groundwater have become a major environmental and health concern. In situations where NO3-concentrations in the soil-water system pose an environmental hazard, water table management may be a desirable practice to reduce such pollution. Careful management of N applications is also believed to reduce NO3- levels. A field experiment was conducted in 1996 and 1997 at St. Emmanuel, Quebec, about 30 km South-West of Macdonald Campus of McGill University, to investigate the effect of water table management (WTM) and N fertilizer combinations on potentially leachable NO3- and denitrification rates in the top soil layer (0--0.15 …  Read more

The objective of this thesis is to examine price performance, and estimate the aggregate export and food crop output response to output price and non-price variables in tropical Africa and its four main agro-climatic regions. The analysis of real producer prices indicates that there are more countries that exhibited a statistically significant decrease in real producer prices than a significant increase. Moreover, nominal protection coefficient analysis shows that African crop exporters, on average, received a small proportion (50 to 60 percent) of border prices. Using pooled cross-section and time series data, a partial adjustment model was then specified to estimate …  Read more

ContexteLes méthodes visuelles participatives (MVP) impliquent les parties prenantes, y compris les groupes vulnérables et marginalisés, en recueillant leurs perspectives et leurs expériences sur des enjeux qui les concernent. Bien que de nombreux chercheurs considèrent l'impact sur les créateurs de médias comme un avantage important, cet aspect reste peu exploré, notamment chez les adolescents en Afrique subsaharienne.ObjectifCette thèse présente une revue de la littérature examinant l'impact des MVP sur les créateurs de médias adolescents en Afrique subsaharienne. Les objectifs sont triples : (i) décrire l'éventail des résultats étudiés en lien avec l'impact sur les créateurs de médias, (ii) résumer les …  Read more

The last decade has seen an exponential increase in the magnitude and consumption of digital information. Online video streaming, cloud storage, the growing number of devices connected to the web via the “Internet of Things”, and artificial intelligence, are emerging applications that require low-latency, high-speed networks. With optical carrier frequencies operating at 100s of THz for common communication wavelengths and optical fibers having both high bandwidth and low attenuation, optical communications in data centers is imminent. However, the bottleneck lies at the interface between optics and electronics, where information is converted from one domain to the other. This work explores …  Read more

Multiphase flow in porous media is a wide-ranging phenomenon, covering such topics as the motion of immiscible fluids, where the interaction with the medium is by exchange of heat and/or mass between phases, to fluid-solid phase flow accompanied by clogging and leaching. The present study is limited to the flow of immiscible fluids (oil and surfactant), where fine solids (clay) migration occurs during the motion. It is divided into two parts: (a) experimental and (b) theoretical. The experimental investigations have been performed in order to evaluate: (a) the factors (e.g., porosity, temperature and injection pressure) that affect the injected surfactant …  Read more

My dissertation provides the first full-length study of representations of domestic material culture in contemporary Canadian women's fiction. The first chapter presents two metaphors, the elephant in the living room, and the open secret, and indicates their usefulness in explaining the cultural and critical tendency to overlook the meanings communicated by contemporary domestic material objects and spaces. Drawing on cultural anthropologist Grant McCracken's research into the role of consumption in the preservation of hopes and ideals, the second chapter examines gendered patterns of consumption in Joan Barfoot's first two novels. I suggest that Barfoot's female protagonists reject their suburban homes …  Read more