McGill University Thèses et mémoires par auteur commençant par N

A survey of Table of Isotopes, published in 1958 by Strominger, Hollander and Seaborg / 64 /, will reveal on first glance in the area of the neutron-deficient isotopes near number 180 that much information, and in particular, decay schemes and disintegration energies, are missing. This applies for ytterbium, Yb166 and Yb167, lutetium, Lu169, 171, Lu174, 178/9, hafnium, Hf170, 171, 172, 173, tantalum, Ta173, 174, 175, and tungsten, W176, 177, 178, 179.  Lire la suite

"In any adequate program of research development, or operation it is necessary to understand the climatic influences involved." (Thornthwaite & Mather, 1955, WB, p. 7). Climate plays an important role in many phases of our contemporary society, whether it be in military or civilian aspects or applied to the past, present, or future events. The bulk of this study was occupied with evapotranspiration studies, and some space is herewith devoted to the history of the project.  Lire la suite

Little, Donald P. (Supervisor)  Lire la suite

Identifier l'application (ou autre classe plus générale) qui génère un flux de trafic Internet, sans compter sur le numéro du port ou inspecter la charge des paquets, est devenu une nécessité pour les opérateurs de réseau. Les opérateurs peuvent utiliser cette information pour surveiller leurs réseaux et fournir une qualité de service propre à chaque classe. Il y a eu beaucoup de travaux de recherche portant sur la classification du trafic Internet effectué récemment et de nombreuses techniques ont été proposées. Bien que les techniques actuelles puissent obtenir une grande précision pour classer le trafic Internet, offrir des garanties de …  Lire la suite

Demographic transition theorists posit that, beginning in the 1960s, biomedical contraceptive technologies and foreign countries, the United States in particular, have been primarily responsible for changes in medical fertility control ideas and practices in Peru. This dissertation argues that biomedical technologies and transnational political actors have played a role, but not always in the ways that demographic transition theorists indicate. The mass distribution of contraceptives such as the pill and the intra-uterine device, for example, depended on the existence of US-funded birth control organizations. However, these birth control organizations did not justify their existence in Peru only in terms of …  Lire la suite

This thesis presents new and efficient analytical solutions for the unsteady subsonic compressible flows past rigid and flexible airfoils executing low frequency oscillations. These solutions are obtained using an especially developed method based on velocity singularities associated with the airfoil leading edge and ridges, which define the changes in the airfoil boundary conditions. The velocity singularity method has been initially developed by Mateescu. Closed form solutions are presented for the unsteady lift and pitching moment coefficients and for the chordwise distribution of the unsteady pressure difference coefficient in the general case of rigid airfoils executing oscillatory pitching rotations and translations, …  Lire la suite

A new method for the determination of the composition of poly($ beta$-hydroxybutyrate-co-$ beta$-hydroxyvalerate) (P(HB-co-HV)) copolyesters, by using optical rotation dispersion (ORD) spectra, was proposed. A linear equation based on the "optical superposition principle" has been shown to relate the specific rotation ($ alpha$) of P(HB-co-HV) samples with their content of $ beta$-hydroxyvalerate determined by $ sp1$H NMR. The microstructure of P(HB-co-HV) copolymers, based on fast atom bombardment mass spectrometry (FAB-MS) analysis of the partial methanolysis or ammonolysis products, is described. The interpretation of the data indicated that the sequence distribution of all samples were statistically random (Bernoullian model), and permitted …  Lire la suite

Adhesion molecules are present throughout embryonic development and during several physiological and pathological processes. Biliary glycoproteins (Bgp) are cell adhesion molecules that belong to the carcinoembryonic antigen (CEA) family, a member of the Ig supergene family. In an attempt to develop a relevant mouse model, we characterized the gene organization, regulation and expression patterns of the mouse Bgp1 gene. The mouse Bgp1 gene is down-regulated upon tumor transformation. This phenomenon has been correlated with a change in the methylation state of the promoter region of the mouse Bgp1 gene. Two other Cea-related genes, called the Bgp2 and Bgp3 genes, that …  Lire la suite

The object of this investigation was to gain insight, by experimental means, into the presumed role of the reticular core in the mechanisms of generalized seizures. Denis Williams, in his recent review article, The Thalamus and Epilepsy (1965), has posed the question in a somewhat different form: "Is the intact centrencephalon essential for the propagation of seizures?" It is not realistic to consider the reticular formation either functionally or structurally in isolation. Its extent, events and effects are by very definition widespread and diffuse. Current concepts of epileptic pathway propagation unfortunately lack precision.  Lire la suite

Since the discovery of the hyperons, that is, the ^ particle and the E particle, and their classification as baryons of strangeness S = 1 by Gell-Mann (1953), there has been considerable interest in the nature of the interaction of these particles with the nucleons. It has been established that the hyperon-nucleon interaction is of the strong type which arises from the exchange of bosons, that is, which is present in the nucleon-nucleon interaction. At low energies, the effects of the exchange of kaons on the nucleon-nucleon interaction may be neglected and the interaction may be taken as arising from …  Lire la suite

Le cancer du sein, le cancer féminin le plus répandu au monde, dont l'incidence augmente au cours des dernières décennies a eu une baisse de mortalitégrace aux nouvelles thérapies. Le sous-type de cancer du sein, répondant différemment aux traitements. Le sous-type triple-négatif, du à l'absence de trois marqueurs moléculaires, de dispose actuellement d'aucun traitement efficace. Le "transforming growth factor β" (TGFβ) est impliquée dans de nombreux processus biologiques allant du dévelopement embryonnaire à la croissance, la différentiation, à l'homéostasie et a un rôle majeur dans le cancer où il joue un rôle double. Dans les cellules normales et dans les …  Lire la suite

This thesis is a study of the effects produced by the intrusion of a basic magna into an impure crystalline limestone. The small area under consideration was mapped and photographs taken of the outcrops. A petrographic study of thin sections was made and photomicrographs taken of the various rock types. From the results obtained during this work, conclusions were arrived at which have a bearing on the theory of the origin of alkaline rocks. [...]  Lire la suite

Humphries, Murray Mitchell (Supervisor1)  Lire la suite

This study examined the effect of density on rhizome bud production in quackgrass (Elytrigia repens (L.) Nevski). The treatments consisted of two biotypes (L8 and L9), and nine density levels ranging from 1 to 22 plants m$ sp{-2}$. The results showed that bud production per plant diminished with increasing density in both biotypes. However, biotype L8 was less productive at low densities, but almost equal to L9 at higher densities. A second experiment was undertaken to measure the expansion of clonal colonies and the distribution of shoots within these colonies. For both biotypes the growth rate was highest in late …  Lire la suite

Objectives. (i) to develop a computationally efficient algorithm of tree-growing for censored survival data, (ii) to assess the performance of two validation schemes, and (iii) to evaluate the performance of computationally inexpensive model selection criteria in relation to cross-validation. Background. In the tree-growing literature, a number of computationally inexpensive model selection criteria were suggested; however, none of them were systematically investigated for their performance. RECursive Partition and AMalgamation (RECPAM) is one of the existing tree-growing algorithms that provide such built-in model selection criteria. Application of RECPAM's different model selection criteria leads to a wide range of models (40). Since RECPAM …  Lire la suite

The impact of different methods of analysis of longitudinal pulmonary data was assessed using computer simulation and a real data set. Thirty data sets were generated: ten without random error, ten with a 10% random error and the other ten with a 20% random error. In each data set, three methods of analysis of longitudinal pulmonary data, i.e., piecewise-linear regression, linear regression and the proportional change model, were employed. In the generated data sets the piecewise-linear regression showed a 26% and 20% increase in precision of estimation of effect of exposure over the linear regression and the proportional change approaches, …  Lire la suite

The effects of the March 1990 deregulation policy on the marketing of agricultural products are examined in terms of price levels, price variability and market integration for maize, tef, noug and sorghum for the Bako, Tibe and Shoboka markets of the Wollega and Shoa regions of Ethiopia. Weekly price data from 1986 to 1993 are used. The price level and price variability changes are tested using a T-test and F-test respectively while market integration is tested using traditional price correlation analysis and Granger's and Johansen's methods of cointegration analysis. Deregulation has resulted in an increase in real prices which has …  Lire la suite

Estradienolone (ED, 17beta-hydroxy-[1,5]-estradien-3-one) is a novel steroid hormone identified in pregnant women. It is an isomer of estradiol which binds the progesterone receptor and sex hormone binding globulin with high affinity. Since levels of ED remain high throughout pregnancy and decrease in association with term or preterm labour, ED may be involved in the maintenance of pregnancy. The objectives of the present study were to, (i) purify ED from pregnancy samples in quantities sufficient for chemical analysis to confirm its structural features, and (ii) identify its binding proteins and receptors. Our results show that ED binds the novel methyltrienolone (R1881) …  Lire la suite

Accessibility, the ability of individuals to reach destinations, has gained increasing prominence in transport planning. Over the past decade, attention has expanded beyond calculated measures of accessibility, which assess the performance of transport and land use systems, to include how individuals perceive accessibility based on their subjective experiences and personal characteristics. As accessibility becomes more integral to planning practice, understanding the impacts of both its calculated and perceived dimensions on travel behaviour is essential for professionals and decision-makers seeking to operationalize it effectively. The main research aim of this dissertation is to contribute to transport planning research and practice by …  Lire la suite

When businesses invest in information technology (IT) they typically do so with the intention of driving a benefit for their various stakeholders. Generally, it has been argued that for IS to generate business value, IT investments need to be made strategically so as not to represent merely bandages to operational problems and inefficiencies and the resulting IS use has to be assessed for its effectiveness in addition to its efficiency (Brynjolfsson 1993). As a result, not only does the IS have to enable and to support the business goals and objectives (Oh and Pinsonneault 2007), but the IS has to …  Lire la suite

Au cours du XXe siècle, les études sur le livre et l’édition ont été inscrites dans le cadre des histoires culturelles ou intellectuelles, d’études sociologiques ou même de l’anthropologie. C’est à partir du siècle actuel que la nécessité de souligner la valeur de l’aspect littéraire et de la littérature dans le domaine éditorial et des livres s’avère fondamentale et que ces questions commencent à être abordées à partir des études littéraires.L’objectif de cette recherche est d’explorer les possibilités de l’édition en tant que pratique créative pour étudier les façons dont différents discours littéraires se manifestent à travers le langage éditorial, …  Lire la suite

Soit $p$ un nombre premier et soit $\Gamma=\SL_2(\Z[1/p])$. Dans l'article \emph{Singular moduli for real quadratic fields: a rigid analytic approach}, Darmon et Vonk ont introduit les cocycles rigides méromorphes et analytiques, qui peuvent s'interpréter comme des symboles modulaires invariant pour l'action du groupe $\Gamma$ et à valeurs dans le $\Gamma$-module des fonctions rigides méromorphes et analytiques sur le demi-plan supérieur $p$-adique de Drinfeld. Soit $k\geq 3$ un entier impair. Nous construisons une correspondance $\mathcal{C}$ à la Shimura-Shintani entre un certain $\bar{\Q}$-espace vectoriel de formes paraboliques de poids $k+1/2$ et l'espace des cocycles rigides analytiques de poids $2k$.La correspondance classique de …  Lire la suite

Arsenic exposure is a major public health problem worldwide. Epidemiological and experimental studies have shown that arsenic exposure is associated with an increased risk of atherosclerosis. The goal of this thesis was to define the role of arsenic biotransformation in the pathogenesis of atherosclerosis. Arsenic is metabolized through a series of oxidative methylation reaction by arsenic (III) methyltransferase (As3MT) to yield methylated intermediates. Using mouse models, we show that methylated arsenicals are pro-atherogenic, and that As3MT is required for arsenic to induce reactive oxygen species (ROS) and promote atherosclerosis. Importantly, As3MT is expressed and functional in multiple plaque-resident cell types, …  Lire la suite

Traditionnellement, les recherches sur la cytoarchitecture corticale ont été menées de manière qualitative par l'examen microscopique du type, de la taille et de la distribution des neurones au sein des couches corticales. Cependant, avec les progrès de la technologie, des méthodes quantitatives (par exemple des méthodes qui quantifient les caractéristiques cytoarchitectoniques) ont été développées pour compléter ou remplacer les analyses qualitatives de la cytoarchitecture du cortex cérébral. Le but de cette étude a été de déterminer les bordures entre les zones cytoarchitectoniques distinctes en utilisant des méthodes quantitatives de parcellisation. Pour atteindre notre objectif, nous avons adapté la méthode d’échantillonnage …  Lire la suite

La nanotechnologie se trouve à l'interface de la physique, de la chimie, de l'ingénierie et de la biotechnologie. Au cours de la dernière décennie, les produits de taille nanométrique, appelées nanoparticules, sont devenus de nature et forme de plus en plus diversifiée menant à un grand essor de la nanotechnologie. Malgré leur immense potentiel, l'application généralisée des nanoparticules est actuellement limitée en raison du manque d'information sur leur biocompatibilité et leurs conséquences néfastes sur les cellules et autres composants biologiques. Nous avons sélectionné des nanocristaux fluorescents de propriétés optiques supérieures, appelés points quantiques (QD), afin d'étudier les interactions entre les …  Lire la suite

In order to understand the development of physical education in Quebec in its proper historical context, it is first of all necessary to understand the general education development in the province. The divisions that are seen to evolve in the one complete education system may help to explain why physical education has grown as it has in the province, and why the division of chapters is as it is in this thesis. This province is the oldest of the Canadian Confederation, European settlement coming in 1608 when Champlain founded the city of Quebec. It is also the largest province in …  Lire la suite

La microturbine Rankine est un microsystème de récupération d'énergie qui convertie un surplus de chaleur en énergie mécanique et électrique à l'aide d'un cycle fermé Rankine qui utilise de l'eau comme fluide. L'appareille est une structure rectangulaire à 5 couches, les dimensions de l'ensemble sont de 1.5 cm x 1.5cm x 1.75 mm. La couche centrale contient deux structures : un rotor qui a un diamètre de 4 mm et un isolant thermique. L'alliage de titan Ti-6Al-4V a été identifié comme un matériel idéal pour les deux composantes. À l'aide d'une revue de la littérature et des essais d'usinages il …  Lire la suite

A digestibility study was conducted in which an identical diet was fed to five species, namely, rats, pigs, sheep, guinea pigs and humans. The diet consisted mainly of whole wheat. As fed, it was found to be unsuitable for digestibility studies with guinea pigs. With sheep, a basal hay diet was fed and digestion coefficients determined indirectly. Variability between individuals was relatively low, for all species, for food fractions other than crude fiber and ether extract. Humans digested crude fiber to the same extent as pigs and rata. The range of the digestion coefficients for crude protein, nitrogen-free extract and …  Lire la suite

During the 1946 field season, three prospecting parties engaged by Mistassini Explorations Ltd. worked in, and northeast of, the Lake Mistassini region. The purpose was to investigate reports of lead, zinc, silver, and iron occurrences, and to outline the geology of the region as a basis for future prospecting. In addition, it was hoped that the contact of the Mistassini sediments and the Grenville gneisses to the east could be traced. The writer was in charge of No. 1 field party, which spent the season in the Lake Albanel area. Two other parties prospected the Takwa River country to the …  Lire la suite

There have been many attempts to elucidate the dynamics of the repeatedly observed increased urinary nitrogen exertion following the administration of adrenocorticotrophin and adrenal steroids. Dr. J. S. L. Browne postulated that these hormones might exert their effect by mobilizing, or "loosening", the body tissue proteins from the internal body sources for the purpose of supplying protein building materials to loci where they might be needed (1). It was suggested that this hypothesis might be tested in the plasma protein depleted rat by studying the effects of these hormones on the regeneration of plasma protein.  Lire la suite

Neisseria meningitidis SD1C exhibited a low tolerance to penicillin G (0.03 (mu)g/ml). Loss of viability was independent of the concentration of antibiotic above the minimum inhibitory concentration, whereas the rate of bacteriolysis was concentration dependent. Penicillin-induced lysis was secondary to cell death. At low but lethal levels of this antibiotic, rapid loss of viability was accompanied by specific ultrastructural changes, yet growth characteristics appeared normal. Subminimal inhibitory concentrations of penicillin G decreased cell numbers and altered the colonial morphology, cellular ultrastructure, as well as the division rate. N. meningitidis SD1C was shown to have six penicillin binding proteins. The binding …  Lire la suite

Embryonal tumors of the central nervous system are the most frequent malignant solid cancers found within the pediatric population. These are currently being researched around the world due to their complex genetic origins, unusual aggressiveness and tendency to be treatment-resistant. Recent work has reclassified a subset of these cancers as embryonal tumors with multilayered rosettes or ETMRs. It has been demonstrated that almost all ETMR patients have one specific epigenetic alteration in common, a chromosomal fusion between the promoter of the tweety family member 1 (TTYH1) gene (which encodes a chloride ion channel expressed in the brain) and chromosome 19 …  Lire la suite

When a beam carries a load, which does not act through its shear center, torsional stresses are introduced along with the flexural stresses. Torsion may be a serious factor in producing beam failures. Rib reinforcement can reduce torsional stresses and angles of twist. The purpose of this investigation was to determine the influence web stiffeners have on these stresses and twist angles.  Lire la suite

A. Results of analyses of tumors produced on beets by Phytomonas turnefaciens confirm the values of previous workers and show that the tumors utilize sucrose for the synthesis of protoplasm and cell wall material rather than for storage as is the case of the normal tissue. B. The first known studies on the metabolism of living slices of plant tumors have been made. c. Comparison of the metabolism of the tumor and normal tissue (of the beet root) shows striking differences in the mode and rate of sugar metabolism. Special attention has been paid to the Pasteur Effect which is …  Lire la suite

The photosynthesis of carbohydrates by the chloroplasts of green plants is an important process, and one that has received considerable study. Most of these studies have been concerned with the effect of external factors, such as light, temperature, and carbon dioxide concentration on the rate of photosynthesis by the plant. These studies have yielded valuable information, but the actual mechanism of photosynthesis is yet unknown; a new line of attack is necessary before the chemioal changes involved in the photosynthesis of carbohydrates by the whole plant can be elucidated because these changes are complicated by other processes, such as respiration, …  Lire la suite