McGill University Thèses et mémoires publiés en 1989

Les eleves inscrits en immersion longue a la commission scolaire laurenvai, qui ont reçu leur diplôme de sixième année aux écoles primaires prince charles et souvenir en juin 1988, ont été identifies au secondaire 1 et 2.  Lire la suite

Rhabdomyosarcoma is a class of malignant neoplasms composed of cells histologically resembling fetal striated muscle. It is the most common soft tissue tumor of children, adolescents, and young adults. In this Thesis, I demonstrate that the rhabdomyosarcoma tumor class is delimited in molecular genetic terms by the expression of the MyoD gene, and that loss of alleles on chromosome 11 distinguishes between the embryonal and alveolar subtypes. The elucidation of this genotypic distinction resolved the paradox between phenotypic variation and an apparent histogenetic relatedness between and among rhabodmyosarcomas. It also allowed for the construction of a two-tiered scheme for the …  Lire la suite

Simulations based on a month of radar data from Florida, and a summer of radar data from Nelspruit, South Africa, were used to quantify the errors in the measurement of mean areal rainfall which arise simply as a result of the extreme variability of convective rainfall, even with perfect remote sensing instruments. The raingauge network measurement errors were established for random and regular network configurations using daily and monthly radar-rainfall accumulations over large areas. A relationship to predict the measurement error for mean areal rainfall using sparse networks as a function of raining area, number of gauges, and the variability …  Lire la suite

The Beam Propagation Method (BPM) together with an accurate Effective Index model is used as a Computer Aided Design (CAD) tool for the analysis, design and optimization of integrated optical devices. The performance of both active and passive 3-branch Ti:LiNbO$ sb3$ waveguide devices as a function of various design parameters is investigated. Then, the device design required to match a specified performance is deduced, and the theoretical performance predictions are verified experimentally through device fabrication and measurements. In particular, a 3-branch passive power divider, a linear mode confinement modulator, and an active 3-branch switch were studied through their design and …  Lire la suite

The human health risk associated with exposure to pesticide formulations applied to New Brunswick forests was examined for 31 sites of cancer, using measures of exposure based on the proximity of non-city population centers to spray areas. Two organochlorine and two organophosphate exposure indices were developed by using maps of areas sprayed each year during the period 1952 to 1976. These data were analyzed in relation to cancer incidence rates during the period 1977-l980 for 254 New Brunswick municipalities. Follow-up case-control studies of the cancer sites considered does not seem to be a matter of high priority at present. However, …  Lire la suite

Textural evidence, high carbonate concentration and septarian cracks in dolomite and calcite concretions and beds of the Middle Ordovician Cloridorme and Cow Head formations indicate early carbonate precipitation during very shallow burial in uncompacted or little compacted host-sediments. These carbonates started to form at a depth not exceeding 5 m from the seafloor, where porosities were as high as 90%, and continued to grow in the sediment column to subsurface depth of 150 meters. Concretions of the Silurian La Vieille Formation and Lower Ordovician Levis Formation started to form at somewhat greater depths of 50 and 350 meters, when porosities …  Lire la suite

The requirement of mitochondrial precursor proteins for cytosolic factors was investigated. The precursor to rat ornithine carbamyl transferase (pOCT) was imported into isolated mitochondria when synthesized in either animal or bacterial extracts. Neither it nor several engineered hybrid proteins could enter mitochondria in the absence of cytosol; import was reconstituted by adding back reticulocyte lysate. The use of one of the chimeras, pO-DHFR, showed that the requisite factor in lysate functions to maintain precursors in an import-competent conformation. pO-DHFR diluted from urea in the presence of mitochondria was imported, but this competence was lost when urea was removed in the …  Lire la suite

Continuous phasing is a technique for cell culturing that is able to reveal metabolic responses during the cycle of cell growth and division. This is accomplished by the correspondence between the periodic addition of a limiting nutrient and the time required for the growth of a generation of cells. The utility of the technique was greatly improved by the development of a feedback system to control the period of nutrient addition. The production of the biosurfactant surfactin was studied using Bacillus subtilis ATCC 21332. The feedback control system was effective in optimizing the period of nutrient addition, resulting in an …  Lire la suite

In this thesis, we establish tight bounds on the maximum size of maximum hidden sets, minimum guard sets, and minimum partitions and covers of polygons, using link-visibility. These results unify and generalize the guard set results (and combinatorial method) of Chvatal and O'Rourke. Our method also provides tight bounds on independent and dominating sets in triangulation graphs, and almost-tight bounds on the size of hidden sets, guard sets, covers, and partitions of polygon exteriors. We also prove that, using link-visibility, the optimization problems of finding maximum hidden sets, minimum guard sets, or minimum covers are NP-hard. Link-visibility is an extended …  Lire la suite

The usefulness of frontal lobe (FL) dysfunction as a conceptual model for Attention Deficit Hyperactivity Disorder (ADHD) was investigated. Twenty-four ADHD and 24 normal control (NC) children were tested using tasks sensitive to FL deficits in motor control and problem solving skills and memory tasks sensitive to temporal lobe (TL) dysfunction. ADHD children differed significantly from NCs on measures of FL function, but not on tests of TL functions. Wherever norms were available for normal children on the same FL tests, ADHD subjects performed like 6 to 7 year olds, in spite of their mean age of 10 years and …  Lire la suite

A study has been made of certain features of the fabrication of a Se-CdO photovoltaic cell having a layer structure usually of the form Al-Bi-Se-CdO-metal. It was found that increasing the substrate temperature during the selenium deposition between 80 and 140$ sp circ$C increased the illuminated short circuit current density in the cell. This clearly demonstrated the necessity of having well-crystallized selenium, as opposed to amorphous selenium, as the active absorber layer in this cell. The CdO layer was normally deposited by d.c. reactive sputtering from a cadmium target in an ambient of argon plus residual air and, as a …  Lire la suite

This exploratory study was designed to identify a range of variables distinguishing long-term unattached (LTU) from long-term committed (LTC) adults between the ages of 30 and 50. Specifically, it attempted to identify explanations for, and consequences of, long-term unattachment. LTU subjects selected were those who had not been in a committed, intimate relationship for eight or more years; LTC subjects selected were those who had been in a marital, or equivalent, relationship for eight or more years. The study was done in two parts. The preliminary study was qualitative and consisted of interviews of 14 subjects--seven LTUs and seven LTCs. …  Lire la suite

Injection molded Short Glass Fiber Reinforced Thermoplastics (SFRTP) are widely used in industry because of advantages in material properties, availability, economics and ease of processing. The thermo-mechanical history experienced by the material during processing produces significantly anisotropic microstructural and consequently mechanical properties, varying not only spatially, but directionally. This work attempts to examine quantitatively various aspects of microstructure and the effect of processing conditions in SFRTP. The matrix phase properties, such as crystallinity, morphology and molecular orientation distribution, as well as the fiber phase microstructure such as concentration, length and orientation distributions have been analyzed quantitatively, and explained. Experimental techniques, …  Lire la suite

The Pd(0) catalyzed coupling reaction of o-dibromobenzene with acetylenes afforded bis acetylenic compounds which were used as precursors for the synthesis of 10, 11, 12, 13, 18 and 20-membered ring systems. The 10-membered benzo-oxadiyne ring 29 is a model compound of the core of antitumor antibiotic calichemicin $ bf{ gamma sp1 sb1}$. Molecular modeling calculations on 29 indicated the possibility of two conformers. A method for the conversion of aryl carboxylic acids to their iodides has been developed. Intermediates were prepared as model compounds towards the synthesis of the antitumor antibiotic neocarzinostatin.  Lire la suite

The objective of this thesis was to determine whether altered transport of a novel sarcosinamide analog of chloroethylnitrosourea (SarCNU) may account for its increased antitumor activity in primary and established glioma cells as compared to BCNU, the agent of choice for chemotherapy of brain tumors. These studies were done in the SarCNU-sensitive SK-MG-1 glioma cells and the 20-fold more resistant SKI-1 cells. Indirect evidence for a sarcosinamide-related uptake for SarCNU was obtained by using cytotoxicity as an indicator for transport in SK-MG-1 cells. The transport of radiolabelled sarcosinamide was shown to proceed via facilitated diffusion, an energy-independent, carrier-mediated process which …  Lire la suite

The mechanism of protein translocation into mitochondria has been investigated by studying properties of precursor proteins destined for the mitochondrial matrix. Characterization of the amphiphilic properties of the signal sequence for pre-ornithine carbamyltransferase has led to the conclusion that precursors can not translocate across the inner membrane via a lipid route alone (i.e. in the absence of proteins). A correlation was established between the rate of precursor import and the degree of hydrophobicity of a short region in the presequence, suggesting that precursor binding to the two-dimensional phospholipid surface of the outer membrane may enhance the rate of diffusion to …  Lire la suite

The Space WARC resulted in significant changes to the regulatory regime of satellite telecommunications. This dissertation examines the Space WARC and its effects. The basis for an understanding of the relevant issues is established by an overview of the resources and technology involved in satellite telecommunications, a summary of the institutional framework, and a review of the events leading to the Conference. The legal and regulatory regime applicable to satellite telecommunications before the Space WARC is examined, including aspects of international space law and international telecommunications law, and the goal of the Conference--equitable access--is analyzed. Both sessions of the Space …  Lire la suite

Policy research in education is a relatively new discipline which deals with the analysis of public policies governing education. The professional literature provides both a conceptual and methodological basis for defining what constitutes a public policy and the means to carry out different types of analysis. Using such a framework, this study analyzes the policy of the Government of Quebec with respect to the education of exceptional children. More specifically, the study focuses on the policy goals and legislative action of the Government. Three separate research questions are each addressed by a systematic analytical framework using a form of qualitative …  Lire la suite

Meredith, T. (Supervisor)  Lire la suite

The main objective of this study was to examine the effects of intraspecific competition on the growth and reproduction of yellow nutsedge. A field experiment was conducted to examine twelve tuber densities of yellow nutsedge, ranging from 1 to 1000 tubers/m$ sp2$. Results indicate that spring tuber populations of 100 tubers/m$ sp2$ and lower require close to 100% control of the infestation in order to prevent the yellow nutsedge population from increasing. Yellow nutsedge spring tuber population does not appear to influence tuber distribution in the soil profile. All tuber densities examined produced the greatest proportion of tubers in the …  Lire la suite

The effects of glucocorticoids and agents affecting membrane phospholipid metabolism on $ beta$-adrenergic receptors ($ beta$AR) have been studied in A549 cultured human lung tumor cells and in IM-9 cultured human lymphocytes. Various glucocorticoids increased the density of $ beta$AR in A549 lung cells but not in IM-9 lymphocytes, although they did increase insulin receptor density in IM-9 lymphocytes. In contrast, bee venom phospholipase A$ sb2$ (0.05-0.2 units/ml), but not phospholipases C or D., downregulated $ beta$AR in IM-9 lymphocytes, but did not affect $ beta$AR in A549 lung cells. Upregulation of $ beta$AR by glucocorticoids was partially reversed by …  Lire la suite

Questionnaires were constructed to measure dieter's beliefs in their abilities to (1) adhere to a diet in eating situations, (2) perform various dieting behaviors, and (3) reach their dieting goals. The three questionnaires were called the Situation-, Behavior-, and Goal-Based Dieting Self-Efficacy Scales. Preliminary work examined the reliability of the three scales. The Situtation-Based scale demonstrated a high level of test-retest reliability over a two to four week period in the two college samples. Examination of scale intercorrelations in the clinical sample indicated that the scales were correlated at only a low level, suggesting that the scales measure different aspects …  Lire la suite

Pseudomonas aeruginosa ATCC 9027 grew in a chemically defined medium with n-hexadecane or glucose, 0.5% (v/v or w/v, respectively), as the sole carbon source, and the K$ sb2$HPO$ sb4$, concentration was either 0.6 mM or 2.3 mM with both carbon sources. Only cells grown on n-hexadecane and 0.6 mM K$ sb2$HPO$ sb4$ produced pyocyanine. The variable lag period associated with cells grown on n-hexadecane was regulated by the state of the inoculating culture, grown on glucose and 2.3 mM K$ sb2$HPO$ sb4$. It was found that organic phosphate was more prevalent in cells grown on both phosphate concentrations with glucose …  Lire la suite

The aim of this work is to offer a quantitative assessment as to what extent the texture and the microstructure influence the cold headability of steel wires. For this, a set of cold drawn low carbon steel wires/AISI 1030 were prepared. The samples were drawn, without heat treatment, in between passes of up to 78% reduction in area (RA) in 5 passes. The deformed samples were then heat treated according to various schedules. Texture development was studied at a given thickness, by measuring the (110), (200) and (211) pole figures by X-ray diffraction; furthermore, the results were represented and using …  Lire la suite

The erosion of copper electrodes in a concentric cylinder geometry with magnetically driven arcs was studied at steady state for currents up to 250 A in a variety of gases and gas mixtures, magnetic field strengths and gas flow rates. The effects of arc velocity, gas composition, current density and heat transfer to the cathode on erosion rates were examined. The arc velocity varied with the magnetic field strength and arc current accordingly to a newly developed equation, V $ alpha$ B$ sp{0.60}$ I$ sp{0.56}$, when the cathode surface was slightly contaminated with C, Cl, O or N. The composition …  Lire la suite

Neurotensin (NT) is a putative neurotransmitter, the central actions of which appear to be mediated by specific high affinity binding sites. Radioautographic studies using emulsion-coated sections have selectively localized a major proportion of NT binding sites over nerve cell bodies in the rat midbrain tegmentum and basal forebrain. In the present studies, it was shown that the vast majority of $ sp{125}$I-NT-labeled neurons in the rat midbrain tegmentum were dopaminergic, while those in the magnocellular basal forebrain of both rats and humans were predominantly cholinergic using adjacent-section light microscopic $ sp{125}$I-NT radioautography combined with either tyrosine hydroxylase (TH) immunohistochemistry or …  Lire la suite

This Study shows that the Shehu's social writings are the reflection of his concept and method of implementation of tajdid. The basic goal of the tajdid was to recreate what he considered the ideal Sunni Islamic society. In order to achieve his objective he unfolded a plan of action which aimed at winning the support of the common people and the 'ulama'. For the people, he mounted a mass mobilization to boost religious learning, acquaint them with local beliefs adjudged as bad innovations, and exhort them about the impending End of Time. For the 'ulama', his plan was a reorientation …  Lire la suite

The standardized patient is one method which can be used in the measurement of clinical competence. The accuracy of reproduction of important features of the patient case by the standardized patient was evaluated in Studies 1 and 2. In 839 encounters reviewed, only 13/89 patients provided an accurate reproduction of the case. Attributes of the patient, training process and evaluation procedure were associated with better patient accuracy. A significant inverse relationship was found between patient accuracy and competence score. In Study 3, the use of standardized patients as raters of behaviour was assessed. There were systematic differences in the scoring …  Lire la suite

The importance of host heterogeneity in generating aggregation was investigated using Heligmosomoides polygyrus (Nematoda) in laboratory mice. The protocol compared parameters of infection between inbred and outbred mice, primary and challenge infections, and gavage and natural exposure, to investigate the relative effects of innate resistance, acquired resistance and behaviour, respectively. The results show that heterogeneity in acquired resistance is the most consistent factor contributing to the variability and aggregation of H. polygyrus. When groups of mice did not acquire resistance, either in certain inbred strains or when mice were immunosuppressed, variability after the challenge was comparable with that after a …  Lire la suite

This thesis presents a method for evaluating the performance of computer systems. The method is based on generating a graphical model of the system using Petri nets and simulating that model to obtain the required performance measures. The collected performance indexes are then analyzed to determine the functionality of the modeled system. The method we present is a hybrid implementation of two very powerful strategies, namely: Petri nets and object-oriented programming. The Petri net model is used to generate precise graphical representations that can model such aspects as synchronization, parallelism, control flow, and data flow. Furthermore, we will emphasize the …  Lire la suite

Bone marrow transplantation (BMT) involves the use of maximal doses of chemotherapy and total body irradiation. As a result, even well-nourished patients exhibit negative nitrogen balance and hypoproteinemia in the post-transplant period, despite a high energy and protein intake from Total Parenteral Nutrition (TPN). The purpose of this research was to investigate the impact of cytotoxic therapy, with a view toward explaining and improving the response to nutritional support. Stool, urine and serum biochemistry were studied prospectively in 10 BMT patients. Analysis of stool revealed increased sodium and decreased potassium. Examination of serum electrolytes indicated hyponatremia and hyperkalemia. A significant …  Lire la suite