McGill University Thèses et mémoires publiés en 2001

The dosimetric characteristics of a standard Varian 52-leaf multileaf collimator (MLC) and BrainLAB m3 micro-multileaf collimator (micro-MLC) have been investigated for square, rectangular, and irregular fields for 6 MV and 18 MV photon beams provided by a Varian Clinac 2300 C/D linear accelerator (linac). The percentage depth dose data and the conventional collimator factor are unaffected by the addition of MLC or micro-MLC shaped field unless, in the latter case, the tertiary field is much less than the jaw setting. However, relative dose factors for a given MLC or micro-MLC field size depend on the jaw setting. The penumbra is …  Lire la suite

Oshima-Takane, Yuriko (Supervisor)  Lire la suite

Idiopathic central precocious puberty may compromise adult height. Gonadotrophin-releasing hormone analogues (GnRHa) suppress puberty and increase final height prediction, but their influence on final height is unclear, especially in girls with pubertal onset just below eight years of age, the traditional limit of normal. At seven children's hospitals, we identified 53 treated and 24 untreated patients (24 and 7 to final height, respectively) whose pubertal onset was between ages 5--8 years. At baseline, bone age advancement and predicted adult height were similar in the two groups. In both groups, the predicted adult height slightly overestimated the final height. What role, …  Lire la suite

This study was conducted using the Leadership Scale for Sports research instrument on 61 high school, 62 CEGEP, 86 university, and 34 professional football players to determine if these players' preferences for five leadership behaviours differed with respect to level of play, unit of play (offensive and defensive), and team success. The leadership behaviours investigated in this study are training and instruction, autocratic, democratic, social support, and positive feedback. In addition, the data collected was analysed to determine if differences were present between football players' preferences for and perceptions of their unit co-ordinator coach's leadership behaviours taking into consideration level …  Lire la suite

Reactive oxygen species (ROS) and nitric oxide (NO) modulate normal and septic skeletal muscle contractility and redox state. We evaluated the involvement of NO synthases (NOS) and heme oxygenases (HO) in nitrosative and oxidative stresses in sepsis-induced diaphragmatic contractile dysfunction. Sepsis was elicited by injecting rats and transgenic mice deficient in either inducible (iNOS) or neuronal (nNOS) isoforms with 20 mg/kg E. coli lipolysaccharide (LPS). Peroxynitrite formation was monitored by measuring nitrotyrosine immunoreactivity with selective antibodies. Oxidative stress was assessed by measuring protein oxidation (carbonyl groups), lipid peroxidation (hydoxynonenal protein adducts), and muscular glutathione concentrations. HO expression was evaluated using …  Lire la suite

The present experiment was conducted to explore the time-course of lexical ambiguity resolution in normal control (NC) subjects and the nature of right hemisphere-damaged (RHD) and left hemisphere-damaged (LHD) patients' impairments in this process. NC, RHD and LHD subjects performed a cross-modal lexical decision task, in which they heard sentence contexts that were biased toward the dominant or subordinate meanings of ambiguous words occurring before the end of the sentence. Written target words related to the dominant or subordinate meaning of the ambiguous words were introduced either at the onset of the ambiguous word (immediate condition), or 1000 ms later …  Lire la suite

Artistic appropriation constitutes a technique that has been widely used by artists for centuries. It seems to have transcended most artistic movements. Appropriation consists of reproducing a pre-existing work, or of being inspired by it, in order to create a new and distinct work of art. Appropriation poses several problems for copyright law because it challenges the basic principle of copyright which provides that a substantial reproduction of a work without the authorisation of the copyright owner amounts to an infringement. Unlike the United States where it was held that an appropriationist work infringed the copyright of a photographer, the …  Lire la suite

Background. Benzodiazepines are sedative-hypnotic medications frequently prescribed in elderly patients for several clinical indications. An association with increased risk for falls has been reported but there is continued debate regarding which specific benzodiazepines are associated with this risk. Objectives. To estimate the risk of injuries from falls associated with benzodiazepine use in an elderly cohort taking into account patient characteristics and changes in patterns of use over time. Methods. Using information from provincial administrative health databases, 462,543 community-dwelling, 66 year old Quebec residents were screened for benzodiazepine use in 1989. Subjects who did not use benzodiazepines in 1989 were observed …  Lire la suite

High pressure (HP) processing has been emerging rapidly as a novel technique for non-thermal preservation of foods. Application of HP processing for shelf life extension of orange juice was the principal objective of the current research. To accomplish this objective, and to establish a scientific basis for HP processing of orange juice, a systemic approach was used which included the evaluation of: (a) HP inactivation kinetics of pectin methyl esterase (PME, the key enzyme in orange juice implicated with respect to quality changes), (b) destruction of spoilage microorganisms and changes in product quality, (c) HP process verification and finally, (d) …  Lire la suite

Fusarium oxysporum M12-4A fungus is being evaluated for the biocontrol of Striga hermonthica, a parasitic weed of African cereal crops. The production of M12-4A inoculum was assessed in four Malian villages using local technology and substrates. A delivery system using arabic gum to temporarily glue inoculum powder onto the crop seed was tested. In controlled conditions, coating of sorghum seeds with arabic gum and inoculum powder did not affect seed germination or inoculum viability. However, one week at 40°C significantly decreased the viability of the inoculum by 31%. Fungus growth and chlamydospore germination were also reduced by temperatures of 34 …  Lire la suite

Receveur, Olivier (Supervisor)  Lire la suite

Fiber Reinforced polymer composite materials offer great potential for waterfront structural applications due to their excellent corrosion resistance, and high strength to weight ratio. The purpose of this thesis is to develop a deflection based design approach for composite sheet pile wall, based on the traditional free-earth support method, but modified to allow the use of deflection criterion. With a simplified earth pressure loading on the wall, the relationship between maximum bending moment and maximum bending deflection and the relationship between maximum shear force and maximum shear deflection were established. 16 case studies were carried out to include walls ranging …  Lire la suite

The critique entitled "L'ecriture du deuil" studies ten contemporary works of literature in light of psychoanalytical theories on mourning. The authors of the chosen pieces are always a grieving narrator going through the long process of mourning and relating the past with the lost loved one. The objective of this memoire is to verify whether or not writing permits the narrators to come to terms with the death, in other words, if it helps them to detach themselves definitively from the lost or inversely, leads them to pathological grievance aimed at reviving the deceased. The work of fiction entitled "Un …  Lire la suite

Since cranberry skin is thick and has low porosity, skin pretreatments were considered before drying in order to facilitate water diffusion. Mechanical and chemical pretreatments were considered, by cutting the fruits in half, by making pin holes in each cranberry, and by dipping the fruits in an alkaline solution. A second pretreatment seemed necessary when drying cranberries in order to reduce their tartness. Cranberries were osmotically dehydrated, by immersing them in osmotic solutions of sucrose or high fructose corn syrup. Once the pretreatment conditions were selected, four drying methods were tested on the pretreated cranberries. These methods included hot air …  Lire la suite

The research presented in this thesis entailed an investigation of heavy metal uptake by Palmaria palmata, a red marine alga. The alga was dry and organically certified. The heavy metals of interest were those commonly found in the wastewaters of the printed wiring board industry, namely Cu2+Pb2+, Cd2+, Zn 2+ and Ni2+. The ultimate objective of the work was to determine whether or not the factors expected to influence the metal uptake to the greatest extent could be optimized within functional ranges, leading eventually to process design (beyond the scope of this thesis). These factors were pH, temperature, initial concentration …  Lire la suite

Degenerating spinal motor neurons in amyotrophic lateral sclerosis (ALS) are characterized by a reduced expression of neurofilament light (NF-L) mRNA and by the presence of inclusions composed of peripherin and neurofilament (NF) proteins. This thesis examines questions related to the formation and toxicity of inclusions containing peripherin. Transfection studies demonstrated that the organization of the penpherin network is disrupted by the larger NF proteins NF-M and NF-H in context of NF-L deficiency. To further investigate the in vivo assembly of peripherin, transgenic mice overexpressing the mouse peripherin gene were generated and then bred with NF-L null mice. Mice overexpressing peripherin …  Lire la suite

Gyorkos, Theresa W. (Supervisor)  Lire la suite

This study examines modern relationships among salt marsh plant species and their pollen in three salt marshes located on the northwest coast of the Bay of Fundy, New Brunswick. Linear regression analysis of pollen in 35 surface sediment samples and vegetation cover on small (<15 m) and broad (>15 m) scales show that, with the exception of Poaceae and Cheno Am, pollen corresponds well with fine-scale patterns of salt marsh vegetation. Scatter diagrams of paired pollen and cover data illustrate that cover of Triglochin is over-represented by its pollen, Glaux is under-represented, and Poaceae, Cheno Am, and Plantago are inconsistent. …  Lire la suite

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 …  Lire la suite

Hristov, D. (Supervisor)  Lire la suite

The mechanisms involved in morphine tolerance are poorly understood. It was reported that calcitonin gene-related peptide (CGRP) immunoreactivity was increased in the spinal dorsal horn during morphine tolerance and an in vitro repetitive morphine treatment was able to mimic the in vivo results by inducing increases in CGRP- and substance P (SP)-immunoreactive (IR) neurons in cultured dorsal root ganglia (DRG). The aim of this study was to validate the DRG cell culture model by establishing which subtypes of opioid receptors are involved in the induction of CGRP and SP in cultured rat DRG neurons and to examine the signaling pathway …  Lire la suite

A method is described that allows one to assess heritability of brain structures using magnetic resonance images (MRI). We have obtained MRI images for a group of identical twins and another group of fraternal twins. Each MRI image was segmented into white and gray matter then smoothed to estimate white and gray matter density at each 3D image element or voxel. At each voxel, we use the intraclass correlations of the two groups in order to compute a 3D image of a measure of heritability, as well as a test statistic for detecting those regions with significant heritability. To our …  Lire la suite

Specific immunotherapy (SIT) treatment of allergies is the controlled administration of a specific allergen to an allergic patient towards the alleviation or remediation of the disease. Successful immunotherapy is associated with a shift in the immune response from type 2 to type 1 phenotype away from IgE production. But the main obstacles in SIT include the need for a standardized source for the allergen and for an adjuvant/delivery system that would promote type 1 immunity to allergens. This work focuses on the recombinant expression of European birch (Betula verrucosa) pollen's main allergen Betv1a with covalent modifications with hydrophobic structures whose …  Lire la suite

This dissertation asserts a strong connection between democratic culture and the novel form in the period 1832--1867. As England debated constitutional reform and the extension of the franchise, novelists Charles Dickens, Elizabeth Gaskell, and George Eliot endeavoured to define human communities on democratic terms. Drawing on work of contemporary political philosopher John Rawls to develop a methodology that considers constitutions and novelistic representations as analogous contexts for reasoning about shared political values and citizenship, this study provides readings of Bleak House, North and South, and Felix Holt that emphasize each novel's contribution to the period's ongoing deliberations about pluralism, justice, …  Lire la suite

At the beginning of the twentieth century, the primitive played a crucial role in the emerging European modernist aesthetic. While art historians have been exploring the role of primitivism in modern art for decades, this area of research has received little attention in musicology. In this dissertation I examine how primitivism is constructed in modern French culture as manifest in three of the most important avant-garde stage works of the first part of the century: the Ballets Russes's Le Sacre du printemps (1913) and Les Noces (1923), and the Ballets Suedois's La Creation du monde (1923). Relying on primary sources …  Lire la suite

Studies of sexual dimorphism in the corpus callosum (CC) have employed a variety of methodologies for measurement and normalization but have yielded disparate results. The present work demonstrates how in some cases different manipulations of the same raw data, corresponding to different commonly used methodologies, produce discordant results. Midsagittal CC area was measured from magnetic resonance images (MRIs) of 137 young normal volunteers. Three strategies intended to normalize for average differences in brain size between the sexes, as well as five different normalization variables, were contrasted and evaluated. The stereotaxic method normalizes for inter-subject differences in overall brain size by …  Lire la suite

Objectives. (1) To estimate cancer incidence in systemic lupus erythematosus (SLE) as compared to the general population. (2) To estimate the sensitivity and specificity of methods of cancer ascertainment. (3) To determine the prevalence of malignancy risk factors in SLE. Methods. (1) We determined the incidence of malignancy in the Montreal General Hospital (MGH) lupus cohort, through linkage with the Quebec tumor registry. Standardized incidence ratios (SIRS) were generated, using Quebec population rates. In addition, a meta-analysis was performed by pooling data from eight cohort studies of malignancy in SLE. (2) We administered a postal survey to cohort members to …  Lire la suite

Automated visual recognition and detection processes are becoming increasingly prevalent in almost all scientific fields and being currently implemented in many fields of industry. In most cases, systems are painstakingly designed and developed in order to detect only a single and specific object or property of an object. The objective of this project was to create a framework of development in which any object distinguishable in a two-dimensional digital image could be analyzed and subsequently detected in other images. Furthermore, as new methods are developed, they could be easily incorporated into this framework to ultimately improve the performance of the …  Lire la suite

The phosphodiesterase (PDE) inhibitors Pentoxifylline (PTX), a general inhibitor, and Rolipram (ROL), a type 4 inhibitor, have been shown to have anti-inflammatory effects. They elevate intracellular CAMP levels and suppress the production of inflammatory cytokines such as tumor necrosis factor (TNF)alpha, interferon (IFN)gamma, and interleukin-12 (IL-12). These drugs have also been reported to modulate the immune response in favor of Th2 responses and to be therapeutically effective in various models of autoimmune and/or inflammatory disorders. Their effects on nitric oxide (NO) production are not well studied. Inflammatory cytokines and NO are important mediators implicated in islet beta-cell destruction. In the …  Lire la suite

Gerwin, Donald (Supervisor)  Lire la suite

Heat transfer enhancement under a single semi-confined turbulent slot jet for planar and non-planar surfaces was studied experimentally by modification of flow region using several configurations of nozzles and turbulence generators (turbulators). The results show both positive and negative effects of heat transfer compared with those for a smooth slot nozzle with the same equivalent width (and length) under the same experimental conditions. The experimental results show that the heat transfer rate for the narrower nozzle of 5 mm width is much higher than that for the wider nozzle of 7.5 mm width at same jet Reynolds number. For planar …  Lire la suite

An experimental investigation into the characteristics of the unsteady laminar shear layer developed over a wall-mounted cavity was conducted, and the effects of the addition of a flush-mounted rotating cylinder to the leading edge or trailing edge of the cavity were quantified through extensive velocity and frequency measurements. It is shown that the injection of circulation resulting from the rotation of the leading edge cylinder caused the shear layer deflect into the cavity and re-attach to the cavity floor at greater cavity depths; also, the additional momentum caused a delay of the formation of shear-layer vortices, interrupting the cavity vortex …  Lire la suite

Chiu, Ray C. J. (Supervisor)  Lire la suite

Curtis, Mark A. (Supervisor)  Lire la suite

Mathematical models and numerical solution methods for the computer simulation of solid particle trajectories in flows of molten aluminum subjected to steady, uniform, electric and magnetic fields are presented in this thesis. The underlying subject is electromagnetic (EM) filtration of molten metals. Attention is focused on steady, laminar, fully developed flows of molten aluminum inside a straight separation chamber of uniform rectangular cross-section. The walls of this chamber are assumed to be electrically non-conducting. The investigation is limited to solid inclusions (particles) that are electrically non-conducting and have an effective diameter in the range 5 mum to 100 mum. Steady, …  Lire la suite

Purpose. There are reports indicating that diuretics may increase the risk of gastrointestinal bleeding. The study was conducted to verify this hypothesis and to assess whether the risk varies with the different types of diuretics. Methods. Using the Saskatchewan health database, a nested case-control design was used, conducted within a population-based cohort of 47,865 new users of antihypertensive medications in Saskatchewan, from 1980 to 1983, and followed up to mid 1987. 753 subjects hospitalized for gastrointestinal bleeding were identified during this period, each of whom was matched with 10 randomly selected controls from a risk set formed at the index …  Lire la suite

Nitrogen and sulfur deposition and water table level fluctuations have the potential to influence the C biogeochemistry in peatlands. Processes in peatland mesocosms were examined under steady state and dynamic conditions at different rates of N and S deposition, and water table levels. Net turnover rates were calculated from diffusive-advective mass-balances of pore water constituents. The limitations of the approach were tested with tracer experiments, which showed that diffusive-advective transport adequately described the flow of dissolved substances in peat columns. Incubation experiments quantified potential CO2, CH4, DOC, H2S and Fe 2+ production rates. The vegetation assimilated most of the deposited …  Lire la suite

Cotler, I. (Supervisor)  Lire la suite

The main scope of this study consists in analyzing how the poetic and ideologic universe of Dante is implanted and transformed in the Russian culture of the late XIXth---early XXth century. Particular emphasis is made on the role of Dante's heritage in the philosophy and poetry of the first Russian philosopher and symbolist poet---Vladimir Soloviov, as well as on the further impact of dantesche images on some major representatives of the Russian Symbolist movement. This analysis will be done through a demonstration of major point of interference between Soloviov and Dante: these can be examples of direct influence (as is …  Lire la suite

The aim of this study is to test the assumption that the depictions of ancient boxing found on Attic Black and Red Figure pottery are accurate. Due to the scarcity of ancient written material and physical evidence, most of our knowledge of the sport must be based on the depictions themselves. This thesis sets out to discover whether or not our basis of knowledge, the vases and their depictions, are accurate and reflect what truly happened in a boxing match. To accomplish this, two main variables are put to test: the ratio of left- and right-handed boxers, and the occurrence …  Lire la suite

The purpose of this investigation was to examine the relationship between quality of work life and motivation of French-speaking Correctional Services Officers (CSOs) working in the Montreal area. Three hundred and forty-seven male and female CSOs (ranging from 19 to 58 years of age) working in four different provincial correctional establishments were assessed. Each participant completed an introductory questionnaire, Pelsma, Richard, Harrington, and Burry's (1989) French-translated 8-item Quality of Work Life Survey (QWL-F) and Blais, Briere, Lachance, Riddle, and Vallerand's (1993) French-translated 8-item Work Motivation Inventory (BWMI-F). Assessment of quality of work life and motivation for CSOs were analyzed with …  Lire la suite

The ideology of jihad as propounded by the Islamic Resistance Movement of Palestine (H&dotbelow;amas) is the subject of this thesis. It examines what this organization specifically means by jihad. To properly ascertain this meaning, the ideology of jihad from two different time periods has been examined. In the first period, the "classical" age, the ideology of several jurists concerning jihad is introduced. It can be seen that during this period jihad was applicable to both the expansion and protection of Islamic social/political hegemony. In the second, or modern period, the interpretations of jihad by four thinkers commonly known as "Islamic …  Lire la suite

The technique of ion transfer in radio frequency quadrupole (RFQ) systems is described. Computer simulations of the gas filled RFQ mass filter system located at Argonne National Laboratory (ANL) in Argonne, Il. are performed and compared to data obtained from the transfer of radioactive ions produced from the fragmentation of an off-line 252Cf fission source put before the system. The device is used to transport radionuclides created in on-line fusion evaporation reactions from a 150 torr helium filled gas cell to a high vacuum mass spectrometer. Operation parameters and performance results for the gas filled RFQ mass filter system are …  Lire la suite

Protein translation in mammalian cells can be divided into three stages: initiation, elongation, and termination, which require several factors. The peptide elongation factor 1A (eEF1A-1), which was formerly referred to as eEF-1alpha, is a guanosine triphosphate (GTP) binding protein and it is responsible for bringing aminoacyl-tRNA to the ribosomes in the process of protein synthesis. The S1/eEF1A-2 factor also referred to as S1, is an isoform of eEF1A-1. Both proteins are expressed from two distinct genes and share 92% identity in their amino acid sequences. Besides the tissue specific expression S1/eEF1A-2, little is known about the functions of the S1/cEF1A-2 …  Lire la suite

Circulation and mixing processes in the St. Lawrence Estuary are examined using both newly acquired and historical observations, as well as numerical modeling. In the Summer of 1997 a field experiment was undertaken to verify the prediction of a three-dimensional numerical model on the occurrences of shear instabilities within the upper estuary. The instabilities were found as predicted and documented from acoustic imaging, current profiler and density measurements. The instabilities, as in the case of Kelvin-Helmholtz instabilities, first develop in the form of wavelike disturbances before they break. The unstable waves have wavelength of around 140--150 m and a vertical …  Lire la suite

The Lame polynomials naturally arise when separating variables in Laplace's equation in elliptic-spherical coordinates. The products of these polynomials form a class of spherical harmonics, which are the joint eigenfunctions of a quantum completely integrable system of commuting, second-order differential operators P0 = DSN , P2,..., PN -1 acting on Cinfinity( SN ). These operators depend on parameters and thus constitute an ensemble. In the main result presented in this thesis, we compute the limiting mean level spacings distribution for the zeroes of Lame polynomials in various thermodynamic, asymptotic regimes. We give results both in the mean and pointwise, for …  Lire la suite

Background. A growing number of patients suffering from ischemic cardiomyopathy are not eligible for conventional revascularization. This has prompted new research in the field of angiogenesis. This study hypothesized that since inflammation is probably the mechanism behind TMR induced angiogenesis; a larger inflammatory response induced by thermal injury may lead to increased angiogenesis. Methods. The model used for this study was coronary artery ligation in the Rat. Four groups of animals were used to compare the novel experimental approach with conventional TMR and with ischemia alone. Neovascularization was determined by immunohistochemical techniques using anti-Factor VIII antibody. Evaluation of VEGF, Ang-1 …  Lire la suite

This thesis examines representations of trust in selected British sentimental novels of the eighteenth century. It focuses principally on the manner in which sentimental prose fiction reflects and participates in the shift from premodern to modern formations of trust. Commenting on the nature of modern trust, Anthony Giddens claims that, with the move to modernity, trust relations in the intimate sphere become increasingly dependent on emotional mutuality, while trust in institutions becomes increasingly impersonal and disengaged from assessments of moral character. My work explores this dual shift in three sentimental novels. It first analyzes Samuel Richardson's Pamela (1740) and contends …  Lire la suite

This research evaluates Quebec's health care policy by analyzing how the partnership metaphor is implemented in policy and practice. The partnership construction is identified in 4 interpretive communities within long-term community services to the elderly population. This analysis focuses on the placement decision for cognitively impaired clients in home care. Interpretive policy analysis is employed to examine 3 policy documents and 3 client files, while grounded theory serves to analyze 13 semi-structured interviews with 2 administrators and 3 open triads of client, caregiver, and case manager. The findings show partnership to be an egalitarian, collaborative ideal widely adopted but with …  Lire la suite

Fischler, Raphaël (Supervisor)  Lire la suite