McGill University Thèses et mémoires par auteur commençant par N

L’IL-17A (IL-17), une cytokine associée à l’asthme sévère chez les êtres humains, régule à la fois positivement et négativement les réponses des cellules Th2 chez les modèles murins de la maladie respiratoire allergique. En plus des cellules Th17, les cellules T γδ ont aussi été décrites comme étant une source d’IL-17 chez certains modèles murins de l’asthme. Alors que les cellules Th17 semblent agir en tant que régulateurs positifs, certaines données suggèrent que les cellules T IL-17-γδ agissent comme régulateurs négatifs aux réponses allergiques des voies respiratoires induites par les cellules Th2. Afin de mieux comprendre l’effet de l’IL-17 sur …  Lire la suite

The behaviour of second phase particles in molten steel processing vessels was investigated, using the E.S.Z. (Electric Sensing Zone) method, in conjunction with aqueous modelling and molten steel systems. 1. Slag droplet entrainment/dispersion is an axisymmetric gas injection stirred system was investigated: A tank containing a water-olive oil simulation of stirred ladles of molten steel was used. Extensive numerical predictions of the oil (slag) droplet population distributions within the vessel were also carried out, and reasonable agreement with the experimental data achieved. Droplet dispersions were shown to be time and spatially dependent. 2. Inclusion separation characteristics in tundishes of continuous …  Lire la suite

The reticular activating system has attracted the interest of psychologists for more than a decade. Theories have been developed, and the concept of arousal has become quite popular in a number of fields of psychology. There are, however, not many behavioural experiments directly dealing with this system, in spite of its theoretical importance. In this thesis, an attempt will be made to reveal the role of the mesencephalic reticular formation, which constitutes a part of the activating system, in some aspects of behaviour. A series of experiments, in which the method of intracranial injection was used, will be reported after …  Lire la suite

Even though the power of supercomputers has increased extraordinarily, there is still an insatiable need for more advanced multi-disciplinary CFD simulations in the aircraft analysis and design fields. A particular current interest is in the realistic three-dimensional fully viscous turbulent flow simulation of the highly non-linear aspects of aero-icing. This highly complex simulation is still computationally too demanding in industry, especially when several runs, such as parametric studies, are needed. In order to make such compute-intensive simulations more affordable, this work presents a reduced order modeling approach, based on the "Proper Orthogonal Decomposition", (POD), method to predict a wider swath …  Lire la suite

The hypothetico-deductive method, which involves an iterative process of hypothesis generation and evaluation, has been used for decades by physicians to diagnose patients. This study focuses on the levels of support that medical information systems can provide during these stages of the diagnostic reasoning process. The physician initially generates a list of possible diagnoses (hypotheses) based on the patients' symptoms. Later, those hypotheses are examined to determine which ones best account for the signs, symptoms, physical examination findings, and laboratory test results. Hypothesis generation is especially challenging for medical students because the organization of knowledge in medical school curricula is …  Lire la suite

Dans le système nerveux central (SNC), la myélinisation réalisée par les oligodendrocytes permet la formation d'une couche de myéline protectrice autour de la membrane axonale, qui constitue la base structurelle de la propagation des potentiels d'action. Quatre études sont présentées dans ce manuscrit de thèse, au cours duquel j'étudie deux aspects clés de la biologie de la myéline dans le SNC : l'organisation moléculaire des paranodes, et la régulation et la distribution des organelles dans la gaine de myéline. Tout d'abord, je présente différents modèles de la distribution des protéines paranodales à l'échelle nanométrique, qui diffèrent des modèles actuellement prédominants …  Lire la suite

This thesis deals with two aspects of operators within the framework of Government and Binding theory; (i) how they are assigned their scope, and (ii) how they are licensed. In an attempt to answer these questions, the relation of Move $ alpha$ (such as scrambling, NP-movement, and wh-movement) to the scope of operators and the licensing of wh-elements, negative polarity items, and adverbs are examined. It is argued that scope assignment is dictated by the Scope Principle and the Empty Category Principle. It is also argued that licensing of operators is determined by the Feature-Dependent Item Criterion. These principles and …  Lire la suite

This thesis investigates chain formation processes in syntax within the general framework of the Minimalist Program (Chomsky 1993, 1994, 1995), where comparison among derivations plays a central role. It is primarily concerned with interactions between Grammatical Function changing (Baker 1988a) and wh-movement. Constructions such as antipassive, applicative, and Object Preposing: (special "passive") from typologically different languages are examined together with their implications for extraction. On a theoretical level this thesis proposes a modification of the notion of reference set (Chomsky 1994, 1995), which fixes the domain of comparison for the purpose of economy. In particular, the notion of reference set …  Lire la suite

Richards, John Brent (Supervisor1)  Lire la suite

Anthropometcic measurements and 24h-recall interviews were conducted on Dene/Metis and Yukon children, and food choice questionnaire interviews were conducted on the mothers of the children. On average, 32% of the children were above the 85th percentile of BMI-for-age in the 2000 CDC Growth Charts. The dietary nutrient intakes were compared to the DRI values. Vitamin A, calcium, phosphorus, vitamin D, vitamin E, dietary fiber, omega-6 fatty acids, omega-3 fatty acids, and magnesium intakes were low. Excessive nutrient intake was not observed. Imbalance of energy intake from carbohydrate and fat and excessive energy intake from total sugar and saturated fat were …  Lire la suite

Several hypotheses concerning the role of fishes in influencing nutrient dynamics in freshwater ecosystems were examined in Lake Memphremagog (Quebec-Vermont). Phosphorus excretion by fishes provides a negligible amount (< 0.33%) in comparison to the quantity taken up by the seston. The phosphorus pools present in the seston and fish community were approximately equal and both were twice the phosphorus content in the zooplankton. Part of this nutrient reservoir is released during the decomposition of fish carcasses. The potential is dependent upon post-spawning mortality rate, the fate of phosphorus in decomposing fish tissue, and the concentrations of allochthonous phosphorus entering the …  Lire la suite

This thesis focuses upon the traditional ecological knowledge of southeastern Hudson Bay Inuit. It provides a detailed assessment of Inuit use and knowledge of a single species, the Hudson Bay Eider (Somateria mollissima sedentaria). Data collected on Inuit classifications of animals reveal the highly-ordered systems whereby Inuit structure their extensive knowledge of the biological diversity of their environment. A lexicon of Inuktitut terms illustrates the refinement of their anatomical knowledge, while detailed data on one anatomical element, the eider skin, serve to indicate the considerable volume of information lying behind these labeled categories. Furthermore, Inuit knowledge of eider ecology provides …  Lire la suite

The second World War which began in 1939 set off a chain of reactions which resulted in the evacuation of all people of Japanese racial origin from the Pacific coasts of both Canada and the United States. It was to be expected that unpleasant consequences for this minority group would occur as a result of Japan’s close affiliation with the axis countries, but it was a surprise to many that mass evacuation was the result of the declaration of war between Japan and the Allied Powers. In times past historians have recorded other evacuations. The British army fearing possible aid …  Lire la suite

Frueh, A. J. (Supervisor)  Lire la suite

Le succès de la réponse antivirale de l'hôte repose sur plusieurs familles de récepteurs qui reconnaissent des structures conservées d'agents pathogènes (PRRs) et qui abouti à la production de cytokines et de chimiokines pour lutter contre l'infection virale et induire une réponse antivirale acquise. Au niveau cellulaire, la production d'interféron (IFN) de type I est régulé à plusieurs niveaux. L'action synergique des facteurs de transcription activés tels que AP-1, NF-kB et IRF sur les promoteurs des gènes de l'IFN de type I déclenche une réponse immédiate qui est amplifiée par la voie de signalisation JAK-STAT. Jusqu'à présent, trois grandes familles …  Lire la suite

We exploit the temporal coherence of closed-form animated implicit surfaces by locally re-evaluating an octree-like discretization of the implicit field only as and where is necessary to rigorously maintain a global error invariant over time, thereby saving resources in static or slowly-evolving areas where per-frame updates are not necessary. We treat implicit surface rendering as a special case of the continuous constraint satisfaction problem of set inversion, which seeks preimages of arbitrary sets under vector-valued functions. From this perspective, we formalize a temporally-coherent set inversion algorithm that localizes changes in the field by range-bounding its time derivatives using interval arithmetic. …  Lire la suite

Kubes, George J. (Internal/Cosupervisor2)  Lire la suite

Daneman, Denis (Supervisor2)  Lire la suite

Our ability to interpret the environment we see does not only lie in processing visual information conveyed through the retina, but it involves more complex dynamics and brain structures that strongly influence our perception. Anatomical evidence has shown the extensive connectivity present between cortical regions allowing information flow in feedforward/feedback manner as well as information flow between areas that are at the same hierarchical level (intermediate-type connections). Feedforward connections have been well characterized functionally and mechanistically. Feedback connections contribute functionally to figure-ground segregation, motion disambiguation, selective attention and several other functions; however mechanistically they have not been well understood. Intermediate-type …  Lire la suite

ABSTRACTBackground and aims:Network meta-analysis allows to draw inferences about the relative efficacy of different agents, even in the absence of head-to-head clinical trials. The purpose of this research was to assess the comparative effectiveness of therapies used for the induction of remission in adult patients with moderate to severe Crohn’s disease based on a network meta-analysis.Methods:A systematic review (SR) of MEDLINE, EMBASE, Cochrane Central Register of RCT/ SR, and Clinicaltrials.gov was performed from 1990 to October 2015. Twenty-eight randomized controlled trials were identified comparing corticosteroids, immuno-suppressants and biologic agents either with an active comparator or with placebo. Relative treatment effects …  Lire la suite

Synaptotagmin I (Syt I) is thought to act as the calcium sensor during regulated exocytosis. We have discovered two novel splice forms of Syt I in the nervous system of Aplysia californica. In the first one, an alternative exon entry site adds two amino acids, V and Q, to the juxtamembrane region that separates the transmembrane domain from the first C2 domain. This splicing event is conserved over the evolution. Overexpression of this form, called Syt IVQ, blocked the ability of serotonin (5-HT) to reverse synaptic depression, while overexpression of Syt I did not. This effect was specific to the …  Lire la suite

Phosphorylation of calcium-activated protein kinase Cs (PKCs) at threonine 634 (T634) and/or threonine 641 increases during long-term potentiation or associative learning in rodents. We have raised an antibody to a peptide from PKC Apl I phosphorylated at T613 and T620 (sites homologous to T634 and T641). This antibody recognizes PKC Apl I only when it is phosphorylated at T613. Both phorbol esters and serotonin increase the percentage of kinase phosphorylated at T613 in Aplysia neurons. Furthermore, the pool of PKC that is phosphorylated at T613 in neurons is resistant to both membrane translocation and downregulation. Replacement of T613 with alanine …  Lire la suite

BackgroundWhile radiotherapy is considered a primary treatment for most head and neck cancers, it can cause debilitating side effects such as hyposalivation, mucositis, and limitation in the mouth opening. These side effects of radiation depend on several risk factors including the radiation dosage and field, tumor size and location, and the existence of temporomandibular disorders (TMD) in patients prior to their cancer diagnosis. Unfortunately, the quality of life of head and neck cancer patients drops dramatically due to TMD disorder symptoms, such as pain and limitation in mouth opening. The development of TMD disorders and hypofunction in oncology patients is …  Lire la suite

Beef heart succinate dehydrogenase (SDH) was solubilized from mitochondrial membranes by a medium containing 4% Triton X-100/4M urea ipH8.6). It was subsequently purified to homogeneity via ion-exchange chromatography on DEAE-Sepharose CL-6B and gel filtration on BioGel A-O.Sm. The pure SDH preparation had a specific activity of 14 - 15.5u moles succinateoxidized/min/mg biuret protein at 38°C in the ferricyanide reductase assay. The pure SDH was composed of two polypeptide subunits (30k and 70k) present at a molar ratio of 1. The N-terminal amino acid residue of the 70k subunit was found to be isoleucine whereas the 30k subunit may have a …  Lire la suite

Ray, Saibal (Internal/Cosupervisor2)  Lire la suite

The state of aggregation of the molecules in a liquid is a problem which has not yet been solved. In a gas it universally considered that there is a random distribution of the molecules, the kinetic energy of the molecules being sufficient to over come any forces of attraction between the atoms or molecules of the gas. In the solid state on the contrary, there is a definite structure. Each atomoccupies a definite position in a crystal lattice, these small units of structure being arranged in a definite manner to make up a larger crystal, which may or may not …  Lire la suite

Le carcinome basocellulaire (CBC) est la forme de cancer de la peau la plus fréquente, mais ses caractéristiques moléculaires demeurent encore partiellement comprises, en particulier en ce qui concerne les phénotypes précoces à haut risque. Ce mémoire de maîtrise présente une étude génomique et transcriptomique intégrée du CBC, s’appuyant sur les plateformes de séquençage à courtes lectures (Illumina) et à longues lectures (Oxford Nanopore) pour l’ARN et l’ADN. Nous avons profilé les mutations somatiques, les gènes différentiellement exprimés (DEGs) et les fusions géniques dans des échantillons de CBC et de tissus normaux appariés, identifiant des signatures moléculaires distinctes associées aux …  Lire la suite

Asim Biswas (Supervisor2)  Lire la suite

Analysis on hydroclimatic variables can provide information on how the climate has evolved over time. This can be accomplished through time series analysis. Trend analysis in hydroclimatic variables is challenging due to their non-stationary nature and the presence of noise and stochastic components in them. The principal objective of this study is to detect and analyze trends in mean surface air temperature, total precipitation and mean streamflow obtained from several stations in Ontario and Quebec, Canada. To accomplish this, we co-utilized the wavelet transform (WT) technique (more specifically, the discrete wavelet transform (DWT)) and the Mann-Kendall (MK) trend test. The …  Lire la suite

Plasticizers are widely used as additives for the production of PVC and other types of plastics. They have been observed to leach out of the solid matrix over the course of the lifetime of the finished product. These compounds have now been observed across the globe and in different environments. The main focus of this work is the study of the interactions of industrial plasticizers with soil microorganisms including bacteria, yeast and fungi. This research is concerned with the microbial degradation of plasticizers such as di-2-ethylhexyl phthalate (DEHP) and di-2-ethylhexyl adipate (DEHA). In particular, the study has focused on the …  Lire la suite

More than one billion pounds of plasticizers are produced each year to supply the plastics industry. Some of these plasticizers, particularly phthalates, are suspected endocrine disruptors. However, few studies have been conducted to determine if they are susceptible to biodegradation by naturally occurring bacteria once they are released into the environment. Six organisms were tested for their ability to grow in the presence of six different industrial plasticizers. Two bacteria, Rhodococcus rhodochrous and Arthrobacter paraffineus, grew well in media containing n-hexadecane and one of the plasticizers. Fermentations in a 2-liter reactor were performed with Rhodococcus rhodochrous and three plasticizers: bis …  Lire la suite

Holt, Richard (Internal/Cosupervisor2)  Lire la suite

The Natural Referent Vowel (NRV) framework developed by Polka and Bohn (2011) proposes the existence of an acoustic-phonetic bias whereby high-salience vowels are preferred over low-salience vowels, resulting in perceptual asymmetries. This dissertation explores the applicability of the NRV framework to consonant manners by conducting two adult and two infant experiments. The first adult study examines the acoustics of stops and fricatives selected for this dissertation and explores English, French and Korean listeners' mapping of English and Persian stops and fricatives to their respective native phonemes. Results of acoustics show that rise time serves as a reliable stop-fricative distinction cue, …  Lire la suite

The problem of causality and its relation to the unity of existence is one of the peculiar themes of Mulla Sadra (1571-1640). Although the treatment of and solutions to the problem of "causality" and the problem of "unity of existence" were considered by previous Islamic philosophers, no one considered these two problems could complement each other. Sadra, through the law of causality, proves the unity of existence. The applications of Sadra's principles (of the fundamental reality of existence and the analogical gradation of existence) which are the central principles of his entire thought, provide his unique theory of "unity of …  Lire la suite

Mir Abu al-Qasim Findiriski (970/1560 1050/1640) a prominent scholar of the Ṣafwid period (906/1501 1148/1736) played an important role in the development of Shi'i Irfan and Ḥikmah. He was a classmate and close friend of Mir Damad (950/1543 1041/1631) and Shaykh-i Baha'i (953/1546 1030/1622). Beside the other major juridical, traditional, philosophical, and mystical accomplishments of the School of Isfahan, the philosophical and mystical contributions of Mir Findiriski are invaluable. Although he was not a fertile writer, the uniqueness of his works has drawn remarkable attention. Many considered him a great teacher of peripatetic philosophy. This thesis aims to display Mir …  Lire la suite

This thesis consists of three studies with the general aim of investigating controlled attention and working memory in the visual and auditory modalities in monolingual and bilingual children equated in visual and verbal working memory as well in bilingual children with and without language impairment. The first study attempts a replication of previous research findings showing a bilingual advantage in controlled attention by altering the methodology to equate children on measures of verbal and visual working memory, as well as adequately measuring language knowledge in each of the bilingual child's languages. In the second study, we performed a preliminary investigation …  Lire la suite

The Canadian government introduced its Multicultural and Employment Equity policies in a series of attempts to induce federally-controlled institutions to reflect the racial diversity of the Canadian population in their programs and workforces. This is a case study of one institution's response to these policies. It examines the implementation of the six-year New Initiatives in Film (NIF) program begun in 1990 by the now-defunct women's filmmaking unit, Studio D of the National Film Board of Canada (NFB) and exposes the fault lines along which the goals of the NFB's various constituent parts clashed and meshed with the diverse goals of …  Lire la suite

Funnell, W. Robert J. (Internal/Supervisor)  Lire la suite

Data presenting two or more sets or related observations may arise in many fields of activity. It is often desirable to measure the relationship which occurs between these two or more statistical series. This relationship may be established and measured by means of correlation techniques. In many statistical problems the relationships among the variables are so complex that simple correlation gives a very incomplete and inadequate answer to the question. In some problems the variables are studied simultaneously in order to find out their interrelations; in others there is one particular variable of interest and the remaining variables are studied …  Lire la suite

Background: Cutaneous melanoma is a cancer with metastatic potential that rapidly increase in incidence in Canada. Recent studies suggest that melanoma progression may involve X-linked genes like FGD1, coding for a GEF protein that activates the RhoGTPase Cdc42. FGD1 influences processes such as cell cycle progression, motility, and extracellular matrix degradation.However, FGD1 specific role in melanoma remains unexplored.Results: Analysis of TCGA melanoma datasets of 500 patients revealed that high FGD1 expression correlates with poor overall survival, particularly in patients harboring BRAF mutations. Gene Set Enrichment Analysis showed that elevated FGD1 levels were associated with a proliferative transcriptional state, whereas low …  Lire la suite

Cette thèse explore des questions fondamentales en gravité quantique à travers l'holographie, employant des méthodes semiclassiques pour sonder la structure des micro-états de la gravité et extraire la physique locale du bulk à partir d'observables de bord. Le thème unificateur est l'utilisation systématique des limites semiclassiques d'intégrales de chemin quantiques pour la gravité et les champs quantiques, chacune révélant différents aspects de la dynamique quantique sous-jacente. Un nouveau point de selle gravitationnel est identifié qui correspond à une observable spécifique pour la cosmologie holographique, et des actions de ligne d'univers de particules uniques sont employées dans la limite haute énergie …  Lire la suite

This thesis discusses the notion of tax evasion in Rwanda. It looks at the role of tax administration and fiscal codes in Rwanda in the implementation of tax anti-evasion measures in the country. The tax administration and fiscal codes provide opportunities for the Rwandan people to realize a tax evasion free society not only because of the tax administration departments in place to curb tax evasion, the types of taxes, the measures of collection, but also the reasonable fiscal procedure process in tax payment and also in allowing the taxpayer participation in the tax assessment process, an essential component of …  Lire la suite

Goudie, Catherine (Supervisor1)  Lire la suite