McGill University Thèses et mémoires par auteur commençant par B

The objective of this investigation was to establish an in vitro counterpart to the in vivo graft-versus-host reaction. The generation in vitro of plaque-forming cells from spleen of rabbits previously immunized with sheep red blood cells could he completely suppressed by the simultaneous incubation of the memory cells with allogeneic circulating lymphocytes, sacculus rotundus, appendix or Peyer's patches cells (collectively referred to as SAPP effector cells). Spleen and lymph node cells were less effective in inhibiting the in vitro immune response whereas thymus and bone marrow exhibited no inhibitory activity. It was demonstrated that the inhibition of the generation of …  Read more

Chromik, Richard (Supervisor1)  Read more

Inherited germline pathogenic variants are responsible for ~5% of breast cancer and ~10% of ovarian cancer. BRCA1 and BRCA2 were established as breast cancer susceptibility genes over twenty-five years ago, and since then, several other genes have been seen to play a role in breast or ovarian cancer predisposition, such as PALB2 and RAD51C. Through rapid expansion and isolation since immigration in the early 17th century, French Canadians are a relatively genetically homogenous population due to genetic founder effects and therefore represent a unique demographic for genetic contributions to disease. To date, twenty variants in BRCA1, BRCA2, and PALB2 that …  Read more

CONTEXTE: Le poids à la naissance est un bon indicateur de la survie infantile et néonatale. Plusieurs études dans divers pays ont comparé les résultats périnataux en fonction de la lieu de naissance des parents. Cependant, la plupart de ces études sont axées sur la lieu de naissance de la mère et d'autres caractéristiques, en négligeant celle du père. OBJECTIF: Le premier objectif est de déterminer si le poids d'un bébé à la naissance diffère parlieu de naissance de la mère et du père.Le deuxième objectif est d'analyser si il y a une relation entre la dureé de residence au …  Read more

A series of studies were conducted to investigate differences in voluntary and evoked contractile properties of trained, untrained and previously immobilized ankle fracture subjects before and following fatigue. Measurements included twitch contractile properties, maximal voluntary contractions (MVC), electromyography (EMG) and muscle activation (interpolated twitch (IT) ratio and second order polynomials). Although second order polynomials were found to be a more precise measurement of muscle activation ($ sim$6% error) than the IT ratio (superimposed evoked torque/potentiated resting evoked torque), both techniques provided a general estimate of muscle activation before and following fatigue. Prior to fatigue, trained plantarflexor subjects exerted greater force …  Read more

This thesis explores the consequences of the shift from active to passive investing, analyzing its diverse impacts on asset pricing, expected returns, investor demand, and price elasticity. The first essay, titled "From Active to Passive: The Consequences for Demand Elasticity'', investigates how the transition to passive investing influences asset demand and price elasticity in the U.S. equity market. It presents a new metric for assessing stock-level passive ownership, which is then incorporated into the existing demand framework. The findings reveal a notable decrease in the price elasticity of demand among all investor types, with passive investment pressure mainly affecting larger-cap …  Read more

The process of metastasis is initiated through the acquisition of inherent and autonomous motile and invasive properties by tumor cells. These phenomena are initiated through a balance between forward cancer cell membrane protrusion and tail retraction, and occur via cell cytoskeleton remodeling, actin reorganization, and coordinated focal adhesion assembly and disassembly events. Among the vast network of cytoskeletal proteins, the actin-bundling protein fascin plays a major function in cell cytoskeleton remodeling. It is a 55-kDa protein involved in the formation of filopodia and cell migration, and found to be upregulated in many cancers. We report herein key functions for fascin …  Read more

Unlike most rodents, the guinea pig (Cavia porcellus) is born with its eyes open. It has been claimed that most of the functional and structural maturation of the retina takes place in utero. In fact, to our knowledge, no study has specifically examined if there was a postnatal maturation of the retina in guinea pigs. The aim of this study was to determine whether the retinal development of the guinea pig continued after birth. The results showed that both photopic (cone) and scotopic (rod) function continue to develop after birth, the former taking more tune to reach maturity than the …  Read more

This thesis analyzes Kenneth Burke's rhetoric of identification. I will examine the extent to which Burke's earliest critical writings, which focus on the suasive nature of literary forms, affected the writing of his later critical works, which deal with how language functions as a type of symbolic action. In his later texts, Burke breaks with his earlier concern with literary discourse by attempting to expound a critical theory that accounts for historical change, human motivation and the role of language in collective communities. He argues that language motivates people to identify with a certain sets of beliefs by transcending an …  Read more

This thesis provides the first systematic measurements of respiratory mechanics in humans anesthetized with halothane. Measurements were made both in anesthetized and anesthetized-paralyzed states. Both active and passive elastance and flow resistance values of the total respiratory system are presented. Next, the passive mechanics data are partitioned into lung and chest wall components. As this partitioning is based on measurements of esophageal pressure, a simple method for validating the esophageal balloon-catheter technique for indirect measurement of pleural surface pressure has also been developed, and applied to anesthetized subjects. In addition, lung mechanics has been studied in awake normal subjects in …  Read more

Martineau, Paul Andre (Internal/Supervisor)  Read more

Joint destruction after intra-articular glucocorticoids was investigated applying histological, biochemical and tracer methods. Adult rabbit knees received 2 – 12 weekly injections of hydrocortisone acetate and were sacrificed thereafter. Fissures and cysts occurred in the midzone of weight bearing joint areas. Their number increased with the amount of hydrocortisone given. A linear decrease of hexosamine to less than 50 percent after 12 injections was accompanied by a marginal change in DNA find hydroxyproline content. The synthesis of proteoglycans and proteins was reduced to one third, while the production of collagen dropped to less than 20 percent. The changes in thymidine …  Read more

The RasGAP—SH3-domain Binding Protein (G3BP1) is an endoribonuclease that links Ras-signalling pathways and mRNA stability. Though implicated in many cellular roles, a well defined function for G3BP1 has yet to be determined. The aim of the following dissertation is to further implicate G3BP1 in mammalian cellular responses to environmental stress, most notably that of Ultraviolet Radiation. We observe G3BP1 transverse from the cytoplasm to the nucleus upon treatment of HeLa cells with apoptotic levels of UVC. Interestingly, forcing its nuclear accumulation in the absence of stress is sufficient to induce apoptotic characteristics. Preliminary observations suggest that plasma membrane signalling and …  Read more

The objective of this study is to evaluate the effect of corrosion on the bond characteristics between the reinforcing steel and the surrounding concrete. The results indicate that as the corrosion level increased, the tension stiffening of the concrete decreased and also the bond between the reinforcing steel and the concrete diminished considerably. Further, the comparison was made between the normal portland cement (NPC) concrete with a water-cement ratio (w/c) of 0.32, NPC concrete a with w/c ratio of 0.52 and NPC concrete with high volume (58% by total weight of cementitious materials) fly ash content, in terms of bond …  Read more

Barrington-Leigh, Christopher (Supervisor1)  Read more

Corriveau, Francois (Supervisor1)  Read more

The US military has considered the possibility of space transportation since the Cold War, but high costs and technological limitations were prohibitive at the time. The rise of commercial space has led to advances in space technology and decreasing launch costs. Private companies are making rapid strides in the development of orbital and suborbital space transportation. Consequently, the US military is assessing the viability of contracting commercial space transportation services. However, the current international space legal regime was not designed for such a scenario. Many aspects of space law and regulation have been developed under the assumption that states would …  Read more

The reverse transcriptase (RT) of HIV-1 contains two active sites, polymerase and ribonuclease (RNase) H that are both absolutely necessary for viral replication and disease progression. While several drugs currently used in the clinic to treat HIV-1 target the polymerase activity of RT, none currently target the RNase H activity specifically. The work contained in this thesis describes a potential intrinsic biochemical obstacle to the development of the most common class of RNase H inhibitors, namely steric competition with the natural substrate. Two active site RNase H inhibitors are studied in detail, β-thujaplicinol and GSK5750. Both bind to the RNase …  Read more

Mazancourt, Claire Seizilles de (Internal/Supervisor)  Read more

There is an historical debate in which the role and importance of the serotoninergic (5-HT) and noradrenergic (NE) systems as being the key components in the antidepressant response is disputed. Alternatively, this contentious debate has directly led to the hypothesis which posits that a combined pharmacological action on both these systems might result in an enhanced antidepressant efficacy. The development of the dual 5-HT/NE reuptake inhibitor venlafaxine has allowed to put to the test this hypothesis. Hence, clinical insight into this problem was provided by studies that documented a greater efficacy of venlafaxine in major depression when used at high …  Read more

Automatic repeat request (ARQ) is a widespread technique for error control in data communication systems. This research examines the performance of conventional ARQ schemes over fading channels. The basic Gilbert-Elliott two-state Markov model is used to represent these channels. This basic model is recursively extended to a 2$ sp{n}$-state Markov chain suitable for n-bit block codes. Using this 'Extended Gilbert-Elliot' model, an approximation of the throughput efficiency of the conventional ARQ schemes is derived. This approximation is particularly valid for slow fading channels. Furthermore, performance plots are obtained, showing the effects of channel fading on throughput efficiency: ARQ performance deteriorates …  Read more

Malgré le succès des thérapies antirétrovirales dans la suppression à long terme de la virémie du VIH-1 chez les personnes infectées, le VIH-1 continue d'infecter deux millions de personnes chaque année et provoque près d'un million de décès. Les approches de guérison et les vaccins sont les priorités de la recherche sur le VIH afin de mettre fin à cette pandémie de plusieurs décennies. Mon projet de recherche vise à comprendre les mécanismes de restriction de l'hôte qui ont posé une barrière à la transmission inter-espèces du VIH, des primates non-humains aux humains. Le but est d'élucider les mécanismes moléculaires …  Read more

Luis, Miranda-Moreno, (Supervisor1)  Read more

The development of two different classes of optical sources for TD-OCT and FD-OCT are presented in this thesis. The design of several low-cost, high-performance BBSs, based on the ASE of two SOAs and EDF, are presented. Two different configuration types that were designed in this thesis are found to be effective BBSs. These sources are implemented in a TD-OCT system and therefore imaging performance is discussed as well. Secondly, two different WSSs based on mode-locked SFRLs with applications in SS-OCT are presented. From our experimental results with BBSs, we conclude that: (1) S/C-band output produced by the ASE emitted from …  Read more

Members of the HSAG family of genetic elements stimulate amplification of the pSV$ sb2$DHFR vector in cis, such that HSAG-pSV$ sb2$DHFR transfected cell populations generate methotrexate resistant cells at a higher frequency than pSV$ sb2$DHFR transfectants. Repetitive DNA sequences such as Alu elements were found in HSAG-1, HSAG-2, and HSAG-5; HSAG-1 and HSAG-2 also contain poly purine-pyrimidine tracts. Analysis of subfragments of HSAG-1, HSAG-2, and HSAG-5 demonstrated that the interaction of multiple positive-acting elements was necessary for maximum amplification stimulatory activity. Proposed positive-acting elements include Alu-like sequences, poly purine-pyrimidine tracts, A/T rich regions and potential stem-loop structures. For HSAG-1, the …  Read more

Al-Saji, Alia (Supervisor1)  Read more

Ce resume analyse le phenomene du racisme dans les oeuvres de l'auteur peruvien Julio Ramon Ribeyro comme etant le reflet de la societe peruvienne contemporaine. L'auteur se sert d'arguments percutants pour confronter l'ordre etabli; un ordre qui refuse toujours d'acquiescer l'existence de ce phenomene. Pour nous, ce fait social transgresse la constitution de cette nation equitable envers tous ses membres, et par le fait meme, merite qu'on l'examine de plus pret et qu'on lui porte une attention toute particuliere. Le premier chapitre decrit le contexte historique de ces recits. De plus, il va inclure une presentation des faits politiques majeurs …  Read more

This work consists of a combination of approaches to understanding the mythological workings of the death and life of Eva Peron. Using the Foucauldian notions of discursive regularities, the study of materialization and meaning in the 'body that matters' by Judith Butler, along with Baudrillard's definition of simulacra and simulation, this thesis traces the diverse constructions and significations of the 'names' and 'bodies' surrounding Evita's life, the treatment of her death, and the period which followed. Throughout the course of this analysis, her names and bodies are subjected to the conception of 'myth' as defined by Roland Barthes, bringing to …  Read more

Since the rise of citizen reporters, blogging, wikis, and pro-am newsroom collaborations, both the professional and academic spheres have come to contest the very definition of a journalist. These analyses, however, often fail to consider the historical complexity of the processes of professionalization in journalism, its systematic institutionalization as an intellectual endeavor, and the fact that there is not – and never has been – a single unifying activity defined as journalism. The lack of a consensual body of knowledge within journalism studies as a field of inquiry, and journalism's problematic status as a discipline within the critical humanities and …  Read more

CONTEXTE: Les innovations en chirurgie thoracique, telles que la thoracoscopie assistée par vidéo (VATS) et les plans de rétablissement renforcé, visent à améliorer les résultats après une résection pulmonaire. Cependant, l'implémentation d'innovations nécessite une augmentation des coûts. Leur évaluation d'un point de vue économique requiert des mesures basées sur les préférences, qui reflètent le concept de rétablissement postopératoire et nécessite sa quantification. Actuellement, il n'existe pas une mesure validée pour le rétablissement postopératoire après résection pulmonaire. L'EuroQol-5 dimensions (EQ-5D) est une mesure générique standardisée de qualité de vie liée à la santé, utilisée à des fins d'évaluation clinique et économique …  Read more

Les matériaux naturels come l'os, les dents, la nacre ou la soie d'araignée offrent des combinaisons de rigidité, résistance et résilience uniques et intéressantes. Pour cette raison ces matériaux commencent à servir de modèle pour de nouveaux matériaux biomimétiques à haute performances. Remarquablement, la structure de ces matériaux aux échelles nanoscopiques ou microscopiques semble suivre un « motif universel » qui consiste en des inclusions rigides fortement allongées (fibres ou tablettes), échelonnées et collée ensemble par une matrice organique ductile et résiliente qui permet de dissiper de l'énergie mécanique de manière substantielle. Cette étude présente des règles de conception unifiées …  Read more

In the first two chapters of this thesis, we address the One-Warehouse Multi-Store (OWMS) problem, a critical inventory control challenge in supply chain management. Motivated by our collaboration with a leading fast-fashion retailer in Europe, we investigate this problem in two scenarios: when the demand is uncensored and when it is censored. For the uncensored demand case, we propose an algorithm based on sample average approximation and the empirical distribution function, enabling continuous learning of the demand and real-time inventory control decisions. This approach delivers significant theoretical and empirical performance improvements. In the censored demand scenario, we develop a primal-dual …  Read more

Beckett, Andrew (Internal/Cosupervisor2)  Read more

The original theory of J.R. Pierce and A.V. Haeff pertaining to the problem of the existence of waves within a narrow beam of electrons of two different average velocities, is discussed. The theory is then extended to the case of wide beams separated by a finite distance. A special case of this theory is then considered, that of a wide pencil of two superimposed streams and the variation of signal amplification that may occur under suitable conditions is studied, as a function of beam width. The results indicate considerable discrepancies between the two theories in cases of narrow beams. As …  Read more

The diffraction of an acoustic wave by an aperture in an infinite plane screen is investigated experimentally and theoretically. Measurements are restricted to circular and square apertures illuminated by an acoustic wave of wavelength of about 3 cm. The diffracted field is examined over a considerable range of distances relative to the plane of the aperture.  Read more

Devic, Slobodan (Internal/Supervisor)  Read more

Despite efforts in developing targeted therapies, cytotoxic chemotherapy remains the standard treatment method of most primary tumours. However, the emergence of tumour chemoresistance contributes to the majority of cancer-related deaths. Understanding the mechanisms that underscore chemoresistance is critical for the development of therapies that target tumour relapse and drug resistance. A key regulator of cellular homeostasis that responds under conditions of low energy is the AMP-activated protein kinase (AMPK). AMPK is a modulator of cell viability in response to metabolic stress. AMPK activation promotes activation of the tumour suppressor p53 following cytotoxic stress. However, the involvement of AMPK in the …  Read more

Indium Phosphide epitactic layers grown by MOCVD and lightly doped with Zn and Mg (p-type) have been studied by Hall effect measurements and secondary ion mass spectroscopy (SIMS). The Zn-doped samples showed a uniform distribution of the acceptor concentration as a function of depth. Mg doped samples showed strong Mg concentration gradients, with substantial diffusion into the substrate. An electrical transport model has been developed for each of the previous cases. These models provided excellent agreement with experiment. The uniformly Zn-doped samples have been used for a detailed study of hopping conduction. Excellent quantitative agreement can be reached between theory …  Read more

The rapidly evolving field of coacervate research has demonstrated that systems generated via liquid-liquid phase separation (LLPS) can serve as simple yet powerful compartmentalization tools. The unique ability of coacervates to sequester target molecules is controlled by their droplet microenvironment, which is in turn dictated by its composition. The development of short peptide-based coacervates further expand the field by allowing for the formation of highly hydrophobic compartments while minimizing the design of their components from polymers and macromolecules to as simple as dipeptides. Despite their versatility and tunability, however, a vacancy is found in the landscape of coacervate systems reported …  Read more

Alzheimer's disease is characterized by (1) senile plaques formed of aggregated amyloid peptides of 40 to 42 amino acids (A$ beta sb{1-40}$ and A$ beta sb{1-42}$) which are derived from the metabolism of the amyloid precursor protein, (2) by neurofibrillary tangles involving a dysfunction of the cytoskeleton due to the hyperphosphorylation of the tau protein, and (3) by amyloid-laden cerebral vessels. The goal of this project is to determine if there is a link between the presence of aggregated amyloid peptides and tau hyperphosphorylation. We incubated the human fetal primary neuron cultures with A$ beta sb{1-40}$ and A$ beta sb{1-42}$ …  Read more

Si les écrivains venus d'ailleurs ont toujours existé au Québec, ils sont désignés et célébrés, après 1987, sous le vocable d' « écrivains migrants ». L'émergence, la nomination et la valorisation des écritures migrantes font écho au discours politique interculturaliste qui prône l'ouverture à l'altérité et une intégration des immigrants respectueuse de leur spécificité culturelle. Le gouvernement du Québec, dans divers documents officiels, jette les bases de sa politique de gestion de la diversité, misant d'une part sur la contribution des communautés culturelles à la vie québécoise, et d'autre part sur la promotion d'attitudes favorables à l'immigration et à la …  Read more

A research version of the Canadian regional finite-element (RFE) model is used to evaluate the capability of the operational model in reproducing the meso-$ beta$-scale structure and evolution of three different types of midlatitude squall-line systems, and to advance our understanding on the development of these features. In this thesis, we use the well-documented 10-11 June 1985 squall line as a test bed to examine the appropriate incorporation of various physical representations and their coupling with RFE's model components. It is demonstrated through a series of sensitivity studies that the operational prediction of squall lines can be improved if more …  Read more

Chaque année, l'industrie des jus génère des milliers de tonnes de résidus de pressage, appelés "marc", qui sont riches en polyphénols. Compte tenu du tonnage annuel généré par l'industrie, la gestion du marc de fruits représente un défi majeur même si cette biomasse est sous-utilisée, peu couteuse, et présente un potentiel industriel de valorisation. Une part des composés phénoliques, qui sont des pigments naturels responsables de la protection contre le stress oxydatif, reste piégée dans le marc (peau et graines) après le pressage du jus. Leur activité antioxydante élevée et leur couleur naturelle pourraient offrir de nouvelles perspectives d'utilisation commerciale …  Read more