McGill University Thèses et mémoires par auteur commençant par H

Positron emission tomography (PET) studies of the human brain reveal pain-related activation in several regions of the cerebral cortex. Nevertheless, patterns of activation vary among studies. This study used the more sensitive method, functional magnetic resonance imaging (fMRI), to assess variability between and within subjects, for both pain and tactile-related activation. Four subjects participated in two fMRI sessions each. Thermal and tactile stimuli were applied to the skin on separate runs. Activation maps were generated comparing painful to neutral heat and tactile to rest. Group analysis revealed pain- and tactile-related activation consistent with the majority of PET studies. Comparison of …  Lire la suite

L'activation aberrante des réseaux de signalisation de protéines-tyrosine kinase est reconnue comme un facteur déterminant de la plasticité du cancer du sein et aussi de sa sensibilisation thérapeutique. La redondance fonctionnelle et l'adaptabilité du kinome de la tyrosine ont entravé des réponses cliniques durables aux inhibiteurs de la tyrosine kinase. La plupart des réseaux de signalisation de la phospho-tyrosine ont en commun l’utilisation de protéines adaptatrices pour la transduction de signaux mitogéniques. ShcA est l'une de ces protéines adaptatrices essentielles à la progression du cancer du sein. ShcA utilise deux domaines de liaison à la phospho-tyrosine (domaines PTB et SH2) …  Lire la suite

The study of the transcriptome, which consists of all RNA molecules in a cell, has been important for elucidating the underlying mechanisms involved in the regulation and expression of genes. Here we describe two studies that apply current high-throughput techniques to investigate two genetic phenomena at the transcriptome level in humans: alternative splicing using whole-transcript gene expression microarrays, and gene fusions using massively parallel transcriptome sequencing (RNA-Seq). Alternative splicing is a post-transcriptional mechanism that allows for the production of multiple transcript isoforms of the same gene, resulting in increased transcriptome diversity. Recently, the global analysis of AS has been facilitated …  Lire la suite

Turcotte, Bernard (Supervisor)  Lire la suite

Ringed seal (Phoca hispida) is a major component and a major source of mercury (Hg) in the Inuit traditional diet. A high correlation between Hg and selenium (Se), as different forms of Hg-Se complex, has been reported in many species of marine mammals. The chemical form of the Hg-Se complex in ringed seals has never be characterised. In this study, Hg and Se concentrations in different seal tissues: liver, kidney, muscle and brain, were measured. The highest Hg and Se concentrations were found in the liver and a strong linear correlation was also observed between Hg and Se concentration in …  Lire la suite

Biochemical sensors have a wide range of applications in medical diagnosis, drug discovery and even food quality monitoring. It is crucial to be able to detect very small concentrations of molecules in a sample with a high selectivity. Here, a cantilever-based sensor to measure changes in the surface stress due to binding or adsorption of molecules is used. This gold-coated cantilever acts as a working electrode and is electrically connected through a potentiostat to a counter and reference electrode in solution. This electrochemical set-up allows the performance of potential-driven measurements. The binding of oligonucleotides to the surface is measured through …  Lire la suite

Le Code d'Atmosph'ere Plane d'Hydrog'ene de McGill (McPHAC) calculela structure en équilibre hydrostatique et le spectre émergent d'une atmosph'ered'hydrog'ene enti'erement ionisée, avec l'approximation en plan parall'ele, pour desgravités de surface comparable 'a celle des étoiles 'a neutrons. McPHAC incorporeprincipalement deux améliorations par rapport aux codes existants pour lesquelsdes spectres modélisés (sous forme de tables) sont disponibles: (1) La dispersionde Thomson est traitée de mani'ere anisotropique, ce qui résulte en une correctionde l'ordre de 0.2-3% pour le flux du spectre émergent dans la bande 0.1-5 keV.(2) La discrétisation de la variable de profondeur dans le cadre du probl'eme detransfert radiatif est …  Lire la suite

While the overall annual incidence of tuberculosis (TB) on the Island of Montreal has been stable at 10 per 100,000 in recent years, incidence varies tremendously by country of birth and by neighbourhood. It is not clear how much of this variation reflects population distribution, and how much reflects localized risk factors and/or local transmission. Precise mapping and spatial statistical analysis allowed for the identification of two types of TB concentrations: hotspots---raw concentrations of cases, and high-incidence zones---where TB incidence significantly exceeds the rate expected. The high-incidence zones were not fully explained by known risk factors for TB, such as …  Lire la suite

Normal outbred rabbits responded to antigenic stimulation with antibody formation through activation of either a two cell (antigen-reactive cell and antibody-forming cell) or one cell (antibody-forming cell) pathway system. Similarly multiple pathway systems were observed to be operative in the induction of cell-mediated immunity. This latter conclusion is based on the fin ding that lymphoid cells of a sensitized rabbit lost the capacity to transfer the delayed hypersensitivity skin reactivity to a normal recipient or to be inhibited in their migration in vitro by the specific antigen although the cell donors were still capable of giving optimal delayed hypersensitivity skin …  Lire la suite

We study the interaction between dislocations and smooth elastic strains in thin film growth. In the first part of the thesis, a continuum model is introduced which, for the first time, includes nucleation, interaction, and dynamics of dislocations in an external stress field in two spatial dimensions. The model implicitly includes the presence of boundaries and their coupling to the elastic strains in the system. In particular, it naturally gives rise to the two well-known strain relaxation modes in thin films: the Asaro-Tiller-Grinfeld (ATG) morphological instability, leading to a grooved morphology of the film-vapor interface, and the nucleation of misfit …  Lire la suite

This study was performed with two main goals in mind. The first objective is to identify the existing problems with current systems and the way they handle the criminal proceedings following an aviation accident. The second goal is to study the need for a unified system which could diminish uncertainty and enhance safety with a growth of trust within and in between the industry and the judiciary. Research and studies performed by many esteemed well-recognized personnel involved in the industry, ranging from lawyers to professors as well as aviation professionals were used in this paper. A comparison was also made …  Lire la suite

To the alchemist it became an apparent fact that certain transmutations would proceed readily whereas others would not. To the modern scientist the processes of transmutation of substances into other substances in the supra-atomic field -- to be distinct from subatomic transmutations -- would be a closed book; if by prededuced constants of the elements and compounds involved he could calculate the state of equilibrium for the transmutation, and by set general principles and rules he could determine the rate of transmutation. The problem of determining the state of equilibrium of a reaction or transmutation belongs to the field of …  Lire la suite

Munz, R. J. (Supervisor)  Lire la suite

Franco, Eduardo (Supervisor)  Lire la suite

Kamal, M. R. (Supervisor)  Lire la suite

The introduction of the tissue slice technique by Warburg and his associates markedly facilitated in vitro metabolic studies. In 1924 Warburg reported that rat brain cortex slices incubated in a glucose-Ringer medium yielded an oxygen quotient (Qo2) of 10.7. Though higher rates have been recorded for the Qo2 of brain cortex slices in normal physiological media, these values have invariably been round to be lower than those calculated for the brain in vivo. Elliott estimating the respiratory rates of the whole brain invitro found that they approximate the rates observed in vivo in conditions of diminished functional activity.  Lire la suite

The subject matter of this thesis is concerned mainly with two aspects of intestinal absorbtion. The first problem deals with the transport of amino acids and amino acid mixtures across the intestinal wall. The second is devoted to the study of transport of simple sugar mixtures. It was thought that the subjects could be more easily reviewed if the literature pertaining to the two problems was reviewed separately. The term intestinal absorbtion implies the passage of substances from the lumen into the blood stream in the intact animal, or from the mucosal solution into the outer serosal solution in in …  Lire la suite

Mutations in the Parkin gene cause a juvenile-onset form of Parkinson's disease (PD) that is transmitted in an autosomal recessive fashion. Studies have shown that Parkin mutations account for far more cases of PD than all other known genetic causes combined. Further, mutations have been identified even in apparently sporadic cases, suggesting a broader role. There is now strong evidence that Parkin functions in the ubiquitin proteasome pathway (UPP), the main system for protein degradation in the cell. Ubiquitin (Ub), a small 76 amino acid protein, can be covalently attached to other proteins. Proteins tagged with Ub are recognized and …  Lire la suite

Glial cells represent the most abundant cell population in the central nervous system (CNS), and yet, have historically been thought of as merely support cells for neurons. Over the past few decades, however, the number of identified roles that glial cells play in the CNS has expanded at an exponential rate, revealing new and exciting functions in neuron-glial communication. At synapses, astrocytes are now recognized as part of a "tripartite" complex with pre- and postsynaptic structures and can modulate synaptic transmission and plasticity. Accumulating evidence has also revealed new roles for oligodendrocytes in regulating axon diameter and integrity, and ion …  Lire la suite

So it’s true, I’ve gone too far pour le quatuor de saxophones et le quintette à cordes joue avec l'étrangeté qu'un auditeur peut ressentir lorsque ce qu'il voit est différent de ce qu'il entend. J'ai découvert que dans les médias fixes, qu'ils soient audio ou vidéo, la réalité perçue est subjective et en constante évolution. Cette idée s'est manifestée dans un projet vidéo surréaliste dans lequel un poulet en caoutchouc est filmé dans de courtes vignettes qui sont généralement existentielles et imprévisibles par nature. Par le biais du timbre, de l'harmonie et de la variation théâtrale, mon travail développe mon …  Lire la suite

An attempt is made to measure the loss tangent of dry air (a non-polar gas) using a resonance-curve method in a spherical Cavity at 1350 mc. The apparatus used is described and is show to possess a high order of frequency and amplitude stability. Although a large number of measurements are made in order to try to obtain a statistical average, the results are indeterminate. The conclusion is reached that the quantity being measured is too small for the apparatus to resolve.  Lire la suite

This dissertation is an exploration of the uniqueness of Canadian law Faculties as sites of meanings about legal education. Through an empirical study, it aims to tease out the institutional cultures of three law teaching institutions: the Legal Sciences Department at the University of Quebec in Montreal, the Faculty of Law at the University of Alberta and the Faculty of Law at the University of Moncton. The thesis notably focuses on the goals they each attribute to legal education, the structures surrounding it and its academic modalities. The findings show that each Faculty associates to such elements a set of …  Lire la suite

Although cities are often conceived as existing in isolation from nature, cities are inherently connected to non-urban ecosystems and cause ecological impacts in rural areas around the world. The demand for most ecosystem services (ES) in cities far outweighs local capacity to produce them, leading cities to appropriate resources from ecosystems outside the city boundary, shaping ecosystems both nearby and far away. Some ES can be provided locally from within a city or nearby (e.g., air purification, recreation) while other ES are sometimes exploited remotely from a rural hinterland (e.g., food, carbon storage). Yet the links between the ES demand …  Lire la suite

Various aspects of Ca2+ uptake into greenhouse-grown potato plants and micropropagated potato plantlets were examined, including the movement of Ca2+ into potato plants and tubers, identification of Ca-packing genotypes and assessment of the effect of improved medium Ca2+ level on different parameters such as plantlet growth, microtuber induction, yield and tissue Ca concentration. The effect of exogenous vitamin Ds and UV-elicited endogenous vitamin D synthesis on regulation of 45Ca 2+ uptake into plantlet shoots was also examined. Safranin dye was not as suitable as the tracer 45Ca2+ for monitoring translocation of Ca2+ into tubers. Uptake of Ca2+ into tubers occurred …  Lire la suite

This thesis describes experiments designed to improve microtuberization efficiency, and to evaluate a range of dormancy-breaking agents for microtubers and minitubers. Provision of continuous darkness, agitation to cultures, mechanical resistance to stolons, or lower levels of medium nitrogen did not improve microtuberization. The 16/8 h d/n cycle at step 1 of microtuberization was significantly better than 12/12 or 8/16 h d/n cycles based on microtuber yield. Cultures exposed to prolonged step 2 or 2 successive harvests, rather than a single harvest at 30--35 d, had significantly improved microtuber yield. In a series of chemical and mechanical treatments applied to microtubers …  Lire la suite

There is currently much work focused on developing packet-switched optical networks to overcome the limitations of existing optical networks. Switch design for packet-switched optical networks is particularly challenging, in part due to the lack of a practical optical memory system. As a result, optical labels and all-optical label processing have attracted much attention. This thesis examines a crucial label processing component of an optical packet switch, namely the label swapper. In this thesis, three different tabletop topologies for low-cost all-optical swapping of spectral amplitude code labels for packet-switched networks are examined in a proof-of-concept phase. The first uses cross-absorption modulation …  Lire la suite

Auclair, Karine (Internal/Supervisor)  Lire la suite

The family of Ismail Sidky participated in the public affairs of Egypt throughout the mid 19th century. His father was Ahmad Shukri Pasha, and his mother was Fatima Hanum, daughter of Muhammad Sayyid Ahmad Pasha, chief of cabinet to Said Pasha, son of Mehemet Ali Pasha founder of modern Egypt. Sidky's father on the other hand was Governor of Cairo, and after the Mahdi rebellion in the Sudan became the Director of the administration of the main territories of the Sudan and its dependencies. When he retired from this position he became Under-Secretary of the Interior.  Lire la suite

The method of drilling and blasting with explosives is widely used in the mining industry for mine development and ore production. However, the use of explosives is associated with rigorous safety and environmental constraints as blasting creates toxic fumes, ground vibrations and dust. The following study is conducted on Soundless, Explosive-Free Chemical Demolition Agents (SCDAs), a more environmentally friendly method for the fragmentation of rock as a potential replacement of explosives. SCDAs are powdery materials similar to Portland cement, which when mixed as a slurry and poured into blind drilled holes, an expansive pressure is produced upon curing and eventually …  Lire la suite

Le forage et le dynamitage avec des explosifs est une technique largement utilisée pour la fragmentation de la roche dans l’industrie manière pour le développement minier et la production de minerai. Pourtant, l’utilisation d’explosifs est associée à des risques sécuritaires et contraintes environnementales rigoureuses tel que le dynamitage génère des émissions de gaz à effet de serre, des vibrations du sol et de la poussière. En conséquence, l’intérêt pour le développement de technologies sans explosifs comme alternatives a augmenté pour la fragmentation de la roche dans les mines souterraines. Cette thèse se concentre sur les agents de démolitions chimique silencieux …  Lire la suite

Most students with neurodevelopmental conditions (NDC) have an impaired ability to communicate, attend to tasks, and appropriately control their body movements (Richler et al., 2010). Repetitive and off task behaviors significantly affect functioning for students with NDC and impede development by interfering with academic activities and limiting social opportunities. Increasing physical activity (PA) in the classroom has recently been explored as a novel teaching method which may address these challenges (Lord, 2010). PA’s such as jogging in place, weight-training, and bike riding have been found to increase social skills as well as improve self-regulation for students with NDC (Lang, 2010; …  Lire la suite

The application of controlled potential electrolysis for the elemental analysis by the inductively coupled plasma for atomic emission spectrometry using a direct sample insertion device will be described. The purpose of the technique is to improve the ICP detection limits over those obtained by conventional nebulization of liquid samples and to separate trace metallic elements from a complex matrix. Preconcentration and separation are achieved by electrodeposition using different electrode types. A conventional graphite electrode, a hanging mercury drop electrode, a reticulated vitreous carbon electrode and a tubular graphite electrode are studied. Advantages and limitations of the different electrodes and techniques …  Lire la suite

Des facteurs internes à l’hôte (facteurs intrinsèques) ou extérieurs à l’hôte (facteurs extrinsèques) interagissent avec le microbiote intestinal et modifient le microbiome. L’étude de ces facteurs fournit des connaissances sur des stratégies de contrôle du microbiote intestinal afin d’améliorer l’état de santé de l’hôte ou de prévenir la maladie. Cette thèse émet l’hypothèse que les métabolites intrinsèques tels que les acides biliaires et les métabolites extrinsèques tels qu’un extrait de pomme de terre riche en composés polyphénoliques (PRPE) modifient individuellement et en coopération la diversité et la composition microbiennes de l’intestin et ont un impact distinct sur le statut métabolique …  Lire la suite

Cette thèse examine le comportement après poinçonnement des raccords dalle-colonne en béton armé dans le but de fournir le renforcement adéquat pour assurer l'intégrité structurale. Les résultats d'essais sur sept raccords dalle-colonne intérieurs sont présentés. L'étude portait sur les effets de l'épaisseur de la dalle, de la longueur des barres d'armature pour l'intégrité structurale, de la distribution de l'armature d'intégrité structurale dans les dalles avec colonnes rectangulaires et sur le placement de l'armature d'intégrité structurale dans les dalles avec des goussets. Les résultats de cette série d'essai et ceux d'autres chercheurs ont été comparés aux prévisions des équations de calcul …  Lire la suite

The design of modern aircraft turbofan engines with low noise emissions requires a thorough understanding of noise generation and absorption phenomena in turbulent mixing jets as well as passive noise reduction devices, e.g. lobed mixers or acoustic liners. At the design stage, such understanding should be provided by reliable and accurate prediction tools to avoid prohibitively expensive experiments. Common acoustic prediction tools are either based on semi-empirical models limited to specific applications, or high-order computational fluid dynamics (CFD) codes, involving prohibitive costs for complex problems. The present study investigates the application and validation of a relatively novel approach in Computational …  Lire la suite

L'émergence généralisée de bactéries résistantes aux antibiotiques a incité les scientifiques à agir rapidement pour développer de nouveaux traitements et pratiques cliniques. La majorité des antibiotiques utilisés en médecine humaine sont des produits naturels avec des structures chimiques complexes et élaborées. Les peptides synthétisés ribosomiquement et modifiés après traduction (RiPPs) constituent une classe de peptides issus de produits naturels qui remplissent de nombreuses fonctions biologiques, y compris une activité antibiotique. La biosynthèse des RiPPs nécessite généralement une maturation en plusieurs étapes de peptides codés génétiquement, souvent catalysée par des enzymes multifonctionnelles.Les lanthipeptides, une classe émergente de RiPPs, sont modifiés séquentiellement …  Lire la suite

The objectives of this study were (l) to screen out active proline-specific peptidases from Lactobacillus casei subspecies, (2) to study growth kinetic and enzyme production from enriched medium (MRS) and cheese whey medium, (3) to purify and characterize two active proline-specific enzymes, and (4) to investigate the action of purified enzyme on bitter tryptic digests of $ beta$-casein as well as bitter enzyme-modified cheese. Lactobacillus casei subsp. casei LLG and Lactobacillus casei subsp. rhamnosus S93 were examined for extra- and intra-cellular proline-specific peptidase activities. Both strains showed strong activity for x-prolyl dipeptidyl peptidase and proline iminopeptidase but had weak activities …  Lire la suite

Considerable attention has been directed towards chemically modified nucleic acid analogs, owing to their rising number of promising applications, ranging from nucleoside analogs as potent antiviral/anticancer agents, modified oligonucleotides for gene silencing purposes, diagnostic agents, functional genomics and target validation. Among various nucleic acid modifications, the work in this thesis is primarily focused on the design, synthesis, and characterization of ring-expanded oxepane nucleosides, 2′-5′ linkage modified siRNAs, and base modified parallel siRNAs. Structural and biological properties imparted by these modifications are investigated, with an emphasis on their structure, drug-like properties, and activity in cell based systems. Our work on oxepane …  Lire la suite

Omanovic, Sasha (Supervisor1)  Lire la suite

Antoniou, John (Internal/Cosupervisor2)  Lire la suite

Borck, Cornelius (Internal/Supervisor)  Lire la suite