McGill University Thèses et mémoires par auteur commençant par R

Goldfish, an exotic originally from Asia, are frequently released into North American waters, causing unknown impacts on native fauna and flora. In the wild, diet overlap between feral goldfish (Carassius auratus) and native red-spotted newts (Notophthalmus v. viridescens) is high, leading to potential interspecific competition over food. In the laboratory, we manipulated densities of goldfish and red-spotted newts to test competition for benthic food organisms between these unrelated species. No intraspecific interference was noted for either goldfish or newts at any density. However, as density increased food resources were more rapidly depleted by both species, suggesting scramble competition. Foraging strategies …  Lire la suite

Valproic acid (VPA) during pregnancy leads to congenital anomalies, possibly by disrupting folate metabolism. Mild deficiency of methylenetetrahydrofolate reductase (MTHFR), an enzyme of folate-dependent homocysteine metabolism, is common due to a polymorphism at bp 677, and may influence response to VPA. To examine interactions between VPA and MTHFR in vivo and in vitro, VPA-induced teratogenicity was studied in Mthfr -deficient mice, and the effects of VPA on MTHFR expression in HepG2 cells were investigated. Mthfr+/+ and Mthfr+/- pregnant mice were injected with VPA on gestational day 8.5; resorption rates and occurrence of neural tube defects (NTDs) were examined on gestational …  Lire la suite

The present experiment was designed to investigate the effects of staging (the sequencing of information) and readers' prior content knowledge on the on-line processing and acquisition of procedural text information. An "expert model" of the procedure was used to manipulate text staging as well as to evaluate readers' processing and comprehension of the procedure. The experimental design consisted of four experimental groups, with six subjects in each group. Subjects at two levels of prior knowledge, experts and novices, were randomly assigned to read one of two differently staged texts, hierarchical and enactment. Various properties of the frame model were used …  Lire la suite

The comprehension of illustrations and text was studied from a cognitive discourse processing perspective. Typically, learners must construct conceptual knowledge representations that integrate different types of information from diverse sources and modalities (e.g., text and illustrations). Currently, little is known about how such integrative processing works in "multimedia" learning situations. This study focused on the semantic representations that low prior knowledge learners constructed as they read from text and static illustrations presenting multiple types of information (structural, functional, and energy) describing a functional system. Both the text and the illustrations were modified so that structural information would be highlighted over …  Lire la suite

Different individuals react differently to infection with similar pathogens and weakly pathogenic organisms can cause life-threatening infections in some, while highly virulent microbes may go undetected in others. The basis of these differences lies within the genetic makeup of each individual, which determine their response to infection. Unraveling the genetic determinants of susceptibility to infection brings a much clearer understanding of the pathogenesis of diseases and paves the way to potential prophylactic and therapeutic interventions urgently needed in the context of increasing antimicrobial resistance, globalization of infectious diseases, and emerging or re-emerging pathogens. Salmonella spp are highly successful pathogens that …  Lire la suite

The goal of the present study was to measure the reactivity of the salivary cortisol in depressed patients and controls exposed to emotional and neutral memory tasks. We recruited 21 depressed patients, 9 in an active phase of depression, 12 in remission and 17 controls. The 3 groups were similar. The protocol consisted of a task to assess explicit memory in two separate conditions: neutral and emotional words to learn consciously on two separate days. During both assessments, we took salivary samples each 10 minutes to assess the concentration of free cortisol before, during and after the memory task. A …  Lire la suite

Typically, when a robotic manipulator undergoes rapid acceleration, there is a commensurate loss in end-effector positional accuracy. To achieve high accuracy of the working end, massive links are usually required. Conversely, to achieve high accelerations, thin and flimsy links have to be employed, only to be plagued by large end-effector vibrations and long settling times. However, this traditional tradeoff can be circumvented through the application of high-performance materials such as graphite/epoxy which exhibits high stiffness-to-weight and strength-to-weight ratios as well as good damping properties. This thesis describes the process of designing and fabricating the three principal mechanisms of an anthropomorphic …  Lire la suite

Ce mémoire a pour objet une lecture de Bouvard et Pécuchet (1881) de Gustave Flaubert à travers le prisme du « comique qui ne fait pas rire ». Le point de départ de ce mémoire est une question : comment expliquer que le comique de Bouvard et Pécuchet, explicitement revendiqué par le romancier dès les premiers balbutiements du projet, ait embarrassé bon nombre de critiques, comme s'il était inadéquat au roman ? Nous verrons comment cette hésitation — Bouvard et Pécuchet est-il comique ou non ? — est inscrite dans le roman, qui déploie un espace, Chavignolles, ambigu et indocile …  Lire la suite

Bovine mammary glands respond to infection by foreign pathogens such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) through changes in gene expression. Monitoring the gene expression profiles will contribute to better understanding of the pathology of mastitis, and provide important selective markers for future animal breeding programs. Using cultured bovine mammary duct epithelial cells and somatic cells from infected bovine mammary glands, this study first examined the existence of Toll Like Receptors in these two systems. In cultured duct epithelial cells stimulated with E. coli LPS, both TLR 4 and 2 mRNA up regulation was detected at …  Lire la suite

Extracellular vesicles (EVs) represent a biologically native system for intercellular communication that is increasingly studied for applications in biomarker discovery and therapeutic delivery in neuropsychiatric disease. This manuscript-based thesis integrates two complementary lines of work that together interrogate EVs both as platforms for engineered central nervous system (CNS) therapeutics and as dynamic molecular readouts of pathology- and treatment-emergent processes. First, we synthesize mechanistic and engineering evidence addressing how EV properties govern their interaction with the blood–brain barrier, their biodistribution, and their capacity for pathology- and cell-type–specific targeting within the CNS. Second, using neuron-derived EVs isolated from peripheral blood, we examine …  Lire la suite

Cette thèse commence en investiguant la modélisation d'une simple chaîne sous la force de la gravité du point de vue d'un modèle Hamiltonien implicite à multiplicateurs Lagrangiens. Un modèle Hamiltonien est ensuite utilisé pour une approche de contrôle moderne d'un «pendubot» avec contrôle basé sur la passivité.Un contrôleur d'oscillation d'énergie amenant le «pendubot» sur une orbite homoclinique destinée à être utilisée avec un autre contrôleur, qui attraperait alors la chaîne en position verticale.Un deuxième modèle, décrivant le système avec des masses ponctuelles est également construit dans le but d'une éventuelle comparaison avec le premier modèle  Lire la suite

There is good reason to believe that the known human cysteine protease repertoire is currently incomplete. Recently, two peptide sequences (i.e. CTLA-2alpha and CTLA-2beta) have been identified in the mouse T-lymphocyte. These peptides have been shown to be similar to the propeptide of human cathepsin L. In this project, computer based searches for human homologues to these mouse peptide sequences has been made. One entry from the TIGR express sequence tag database has been identified. As part of this project, the tag was isolated from the human Jurkat cell mRNA, a cell line compatible with the source of RNA used …  Lire la suite

We consider the problem of rendezvous between two robots exploring an unknown environment. That is, how can two autonomous exploring agents that cannot communicate with one another over long distances meet if they start exploring at different locations in an unknown environment. The intended application is collaborative map exploration. Ours is the first work to formalize the characteristics of the rendezvous problem, and we approach it by proposing several alternative algorithms that the robots could use in attempting to rendezvous quickly while continuing to explore. The algorithms are based on the assumption that potential rendezvous locations, called landmarks, can be …  Lire la suite

This dissertation analyses the convergence of primitivism and nationalism in late-nineteenth and early-twentieth century French and Russian art. The discourse of primitivism has yielded a number of critical studies focusing on the artistic appropriation of aesthetics derived from "tribal" arts, Asian arts, medieval icons, outsider art, and peasant arts and crafts. Within that scholarship, modern European art that appropriates the aesthetics of folk arts and themes of the peasantry is frequently considered to be representative of national identity and myth. The artistic elucidation of the peasantry as emblematic of national identity combined with their incorporation into primitivism produces a tension …  Lire la suite

This thesis describes a simple technique for the quantitative in vivo analysis of nonradioactive iodine. The method uses the X-ray absorption discontinuities for the detection of iodine in the presence of any other absorbing substance. [...]  Lire la suite

Les distributions pour les données non-Gaussiennes sont fréquemment nécessaires pour les processus spatiaux et spatio-temporels, ce qui mène les analystes à recourir à des hypothèses Gaussiennes après une transformation appropriée des données. Cependant, modéliser les données sur leur échelle originale tout en accommodant le comportement non-Gaussien est préférable pour mieux quantifier l’incertitude des prédictions. Des difficultés surviennent aussi lorsque la variabilité des processus montre des patrons que les méthodes de transformation ne peuvent pas facilement accommoder. Des modèles proposés récemment qui évitent les transformations arbitraires utilisent deux processus Gaussiens (GP) indépendants. Un mélange de localisation d’un GP utilisant un log-GP …  Lire la suite

Fragmentation is the process by which bare quarks dress themselves up as hadrons. Since we cannot get reliable calculations of this process using perturbative quantum chromodynamics, the fragmentation properties of quarks must be obtained empirically. We report on the signal extraction and relative transverse momentum (pT) spectrum determination that will lead to a high precision measurement of relative fragmentation fractions of b quarks into B hadrons, in 1.96 TeV pp¯ collisions. Using 1.9 fb-1 of data taken with the CDF-II detector, we fully reconstruct 473 +/- 42 B0s→D-sp + , 15206 +/- 203 B0 → D-pi+, 1483 +/- 45 B0 …  Lire la suite

Measurements of vertical and horizontal components of hydraulic conductivity were made by the falling head permeameter, the standard piezometer and the piezometer with packing device on 4 farms in the Saint-Lawrence lowlands of Quebec, Canada. All fields are considered to be between imperfectly and slowly drained. The values obtain by the 2 types of piezometer were calculated with the aid of 3 different equations and were compared. The falling head permeameter technique was found to be not appropriate to study anisotropy in clay and clay loam soils due to its high variability and small volume of soil sampled. Both piezometers …  Lire la suite

Curieux objet d’étude que les traductrices de la Renaissance! Dans leurs écrits liminaires, prenant la parole en leur propre nom, elles se façonnent une image morale propre à capter la bienveillance du lecteur et elles exposent, plus ou moins directement, leur conception de l’acte traductif. Mais les voies qu’elles empruntent varient singulièrement. Hélisenne de Crenne, traductrice de l’Énéide, emploie un vaste appareil paratextuel pour camper son ethos d’humaniste. La traduction, pour elle, est un labeur méritoire, un exercice d’érudition, un don au public, un ressort de la translatio studii, enfin, un moyen de couronner son parcours auctorial. Rien de tel …  Lire la suite

The mechanism of natural resistance to endotoxin was studied in inbred strains of mice. Characteristic patterns of sensitivity to lipopolysaccharides (LPS) extracted from strains of S. typhimurium (Keller, SR-ll, M-206) were observed in inbred mouse strains A/J, C57BI/6J, A/HeJ and C3H/HeJ. Toxicity of acetone dried cells was also investigated in A/J and C57BI/6J mice using strains of S. typhimurium with complete (Keller, and M-206) and incomplete (Rb3 and Re) chemotypes. The susceptibility of the mouse strains to S. typhimurium infection did not parallel their sensitivity to endotoxin. The amount of 51Cr-labelled LPS found in the liver of mouse strains A/J, …  Lire la suite

This research wanted to test if the Job Characteristics Model was good to study school principals' motivation in the province of Quebec. To run the study, the Job Diagnostic Survey created by Hackman and Oldham was used to collect school principals data. To this questionnaire, a part was added to collect sociodemographic data. Using these data, one way analysis of variance was used to find out if there were significant differences between the means of school principals. The results obtained indicate that the Job Characteristics Model is not exactly the right means to study school principals' motivation. But the analysis …  Lire la suite

Environmental regulation of nitrogen cycling processes, denitrification and nitrification, was studied in sediment of Hamilton Harbour, with particular emphasis on the role of CH$ sb4$ metabolism (production and consumption). Through extensive sediment sampling and numerical analysis, it was found that particulate carbon was the best predictor of potential for anaerobic production of CH$ sb4$ and CO$ sb2$. The only predictor of denitrification capacity was anaerobic CO$ sb2$ production, indicating that beside NO$ sb3 sp-$ and O$ sb2$, a biotic factor involved in carbon metabolism may be important in the control of this activity. Suppression of aerobic N$ sb2$O production in …  Lire la suite

This thesis endeavors to render anarchist thought more appropriate to contemporary political life. It attempts to show that what is needed is not an overarching theoretical system, but rather explorations of new organisational forms. I will try to demonstrate that supported by anarchistic trends in social theory, anarchical organisational forms are taking place to some extent in practice. These transformations, it is maintained, are a desirable political response to contemporary technological change.  Lire la suite

This study compares the willingness to pay values from two different stated preference methods, choice modeling (CM) and contingent valuation (CV). The CV approach used was a multiple bounded discrete choice (MBDC) format. The WTP values were estimated for different food products that contained different environmental and health attributes. The two methods were found to generate statistically different WTP estimates for tomatoes and pork and were statistically similar for milk. The difference seems to reside in the model specification; when the attributes were analyzed as non-linear, the WTP estimate using the CM method was statistically similar to the one estimated …  Lire la suite

The main objective of this research is to explore new economic methods to evaluate and promote ecosystem services from agriculture. The three studies present economic methods to assess and improve the sustainable development of the agricultural sector.The first study evaluates agricultural land as a source of natural capital in the province of Quebec using a geographic information system coupled with a spatial hedonic pricing model of agricultural land transactions during the period 1990-2010. The results show that although the total area has increased slightly, the average real value per hectare has decreased over time suggesting the average quality has decreased. …  Lire la suite

The current study explored gender differences in groups of boys and girls in a limited resource context. Forty same-sex groups of four children from kindergarten and grade four were observed during sessions in which groups played first with two different toys and then two different games. The toy and game sessions were constructed so children had to negotiate for a scarce resource (attractive toy and game winner's certificate). In the case of one of the toys the end of a player's turn was obvious to group members (explicit turn-taking toy), in the case of the other toy the end of …  Lire la suite

This Master's Thesis analyses the work of Charles Cotin an abbot and a poet who, between 1630 and 1665, successfully proved himself in the Literary Salons of France. This thesis will try to determine how his work illustrates well the Gallant esthetics and how his poetical choices reflect but also challenge the great tendencies of the Gallant literature. The analysis of Cotin's Work divides itself into three facets: Lampoons, Religious texts and Gallant poetry. The Gallant esthetics is shown differently as Cotin progressively extricates hermeneutic rules and then try to adapt Theology to the King's entourage. Cotin's work will also …  Lire la suite

Les indolizines sont une cible de choix en chimie médicinale. À ce titre, plusieurs approches permettant de générer cette structure ont été développées. Toutefois, la plupart des méthodes existantes soit requièrent la préfonctionnalisation des réactifs de départ, soit permettent peu de variations dans la position et l’identité des substituants du produit. Ainsi, une synthèse efficace qui générerait rapidement des indolizines aux structures variées à partir de réactifs simples reste élusive. Pour pallier ce problème, le chapitre 2 décrit la synthèse d’indolizines via une réaction multicomposants et monotope catalysée au palladium à partir de 2-bromopyridines, d’imines, de monoxyde de carbone et …  Lire la suite

The 5$ sp prime$ untranslated region of human immunodeficiency virus type 1 (HIV-1) mRNAs comprises the cis-acting target sequence TAR responsive to the viral transactivator protein Tat. The TAR sequence folds into a stable stem and loop structure and interacts with two proteins: Tat and the cellular double-stranded RNA dependent protein kinase P68. The Tat-TAR interaction is centered on a tri-nucleotide bulge in the RNA. It is thought to bring Tat in proximity to the transcription complex and augment, in an ill-defined manner, the processivity of the RNA polymerase. The P68-TAR interaction is dependent on the integrity of the RNA …  Lire la suite

The first three studies in this thesis address the mechanism for the aberrant fall in serum 1,25-dihydroxyvitamin D$ sb3$ (1,25-(OH)$ sb2$D$ sb3 rbrack$ and increase in renal 1,25-(OH)$ sb2$D$ sb3$-24-hydroxylase(24-hydroxylase) activity in X-linked hypophosphatemic mice (Hyp). The 24-hydroxylase is the first enzyme in the C-24 oxidation pathway that degrades the vitamin D hormone to its final inactivation product, calcitroic acid. We demonstrated that: (i) the aberrant increase in 24-hydroxylase activity in Pi-deprived Hyp mice is specific to the kidney and is the result of an increase in enzyme Vmax, immunoreactive protein and mRNA abundance; (ii) the increase in 24-hydroxylase mRNA …  Lire la suite

Old Harry is an oil and gas prospect located in the Gulf of St. Lawrence on the border between Quebec and Newfoundland. It has neither been drilled nor exploited yet, but the Government of Quebec has demonstrated openness to its exploration and the federal government has yet to adopt any statute regulating offshore oil and gas exploitation in Quebec. However, the 2010 BP Deepwater Horizon case has shown there are important risks that come with this exploitation. The purpose of this study is to analyze Newfoundland’s legislation to highlight the strengths and weaknesses of its civil liability regime for oil …  Lire la suite

The design and mechanical performance of a helicopter horizontal stabilizer slat made by resin transfer moulding (RTM) can be evaluated with finite element analysis (FEA). To verify the validity of the assumptions used in the modelling of the slat structure, static mechanical tests were performed on prototype slats which were half of the full-size length. The slat complex boundary conditions were simplified to make static mechanical testing possible. Two fixtures were designed and built to introduce simplified loads in specimens with two different bracket configurations: a full and a half bracket. A finite element (FE) model of the specimens was …  Lire la suite

Naseem, Anwar (Internal/Supervisor)  Lire la suite

Faces provide important information necessary for social communication. The current study aimed to evaluate Event-Related Brain Potentials (ERPs) as a method of exploring face processing abilities in fragile X syndrome (FXS), a genetic disorder where social deficits lie at the core of the cognitive phenotype. Neural changes were investigated in three children with FXS across various conditions such as upright vs. inverted faces, intact faces vs. faces with no eyes as well as faces vs. cars. Relative to chronological age matched controls, children with FXS displayed greater N170 amplitudes and shorter latency peaks across conditions. In addition, the FXS group …  Lire la suite

From the early 1900s to the mid-1910s, the Japanese colonial regime in Taiwan launched a series of brutal military operations aimed at conquering the island’s aborigines territories. As the Japanese army and police secured their control of aboriginal lands, anthropologists also began traveling to Taiwan. Hoping to develop theories that would link Japan’s ethno-racial ancestry to the South Pacific, these anthropologists constructed various racial taxonomies to divide up the island’s various tribes. These taxonomies helped justify deployment of Japanese police forces across Taiwan’s aboriginal lands during the period of violent military campaigns undertaken by the colonial state from the early …  Lire la suite

A two-dimensional numerical investigation was performed to determine the effect of a Gurney flap on symmetric and cambered airfoils at very low Reynolds number. A Gurney flap is a device consisting of a small tab attached at the trailing edge and perpendicular to the chord line of the airfoil. Originally installed on a race car wing, a Gurney flap was proven to have a positive influence on the lift to drag ratio, and leading therefore to better efficiency and performance. First studies of Gurney flap showed that the optimal length of such a device is in the order of 1-4% …  Lire la suite

There is growing evidence that the achievement of biodiversity conservation objectives at the regional scale will have to take into account not only habitats within reserves, but also the contribution of semi-natural habitats in production landscapes. This requires knowledge of the conditions that maintain or enhance biodiversity in these suboptimal habitats. I focused on a system of forest patches and hedgerows in an agricultural landscape as habitats for dispersal-limited native forest herbs to (1) identify species-specific traits that appear to either limit or facilitate survival or colonization of forest herbs in hedgerows compared to forest patches, and (2) to evaluate …  Lire la suite

The society is becoming increasingly more energy and environmentally conscientious, which has forced development of construction materials, which are both inexpensive and require very little energy to produce. One way of producing such materials is to utilize by-products of industrial processes. High-volume fly ash cement based grouts are tributary of such developements. This thesis outlines the results of a detailed study of the grain size distribution, three rheological properties and five mechanical properties of high-volume fly ash grouts (60% cement replacement for fly ash by weight) with or without the use of superplasticizers and/or anti-washout agents. The rheological properties are …  Lire la suite

This dissertation is an analysis of writings and illustrative material by Canadian travel writers Anna Jameson, Mina Hubbard, and Margaret Laurence, that attempts to reconcile the masculinist focus of postcolonial criticism and the charges of cultural imperialism levied against feminist criticism with the role postcolonial and feminist theories play in understanding women's travel narratives. I argue that Jameson's 1838 Winter Studies and Summer Rambles in Canada, Hubbard's 1908 A Woman's Way through Unknown Labrador, and Laurence's 1963 The Prophet's Camel Bell provide maps of the political, cultural, and physical features of the areas through which the women travelled, and of …  Lire la suite

The whole problem of racial division of labor in Canada dates from 1760. Amherst's capture of Montreal in that year broke down the political barrier established by the French Empire and opened the St. Lawrence frontier to the expanding commercial communities of the Atlantic seaboard colonies. The clash which followed between the profit-seeking Yankee and British trader, eager for new fields to exploit, and the French-Canadian habitant, resulted in social and economic complications which have been written deeply into Canadian history. The invading commercial groups secured control ot the fur trade--the French-Canadian remained a "coureur de bois"--and their eoonomic dominance …  Lire la suite

Long suspected of being frivolous, of cultivating bad taste and of encouraging its reader's chimerical daydreams, the novel, at least after Cervantes, curiously turned against itself in the name of the reality it was once accused of fleeing. In doing so, it changed radically, of course, since it separated itself from the old idealistic romances which it now named as its enemies; but it also remained, more discreetly perhaps, faithful to its origins, i.e. to the lies and illusions whose profound and secret necessity novelists have never ceased to reaffirm. This dissertation is a meditation on the paradoxical foundation of …  Lire la suite

Fictional characters who mistake reality for fiction can be considered as parodies, beings invented by the author to denounce the illusions of which they are victims. But this viewpoint is not valid if the novels in which those "mistaken readers" exist suggest, to the contrary, that reality is problematic; it is therefore impossible to judge the characters without "afterthoughts", since these characters, in a way, are pointing to the fact that the reality they live in is "unreal". Such is the case with Madame Bovary and Don Quijote. These two novels, as a result of different "techniques", essentially tell their …  Lire la suite

Orsat, Valérie (Internal/Cosupervisor2)  Lire la suite

This thesis aims to show how the Narrator's illness, in À la Recherche du Temps Perdu (In Search of Lost Time), enables him to lay the foundations of a unique interaction with Time. The assumption that underlies this study is that illness becomes for the Narrator the passive manifestation of his resistance to consensual norms, including a certain conception of reality and Time. This thesis explores how beneficial living in a state of illness can be for the Narrator, allowing him to create his own temporal space, the "time of illness", instead of experiencing the normal "time" of daily life. …  Lire la suite