McGill University Thèses et mémoires par auteur commençant par A

Résumé Ce Mémoire discute de l‟influence de la charge de surface (i.e. potentiel de la surface) sur la cinétique et la thermodynamique de l‟adsorption du sérum de l‟albumine bovin (BSA) sur la surface d‟acier inoxydable de calibre biomédical. La technique de la spectroscopie de modulation de polarisation en réflexion infrarouge (PM-IRRAS) fut efficacement utilisée pour cet objectif. Il fut observé que la cinétique d‟adsorption du BSA sur une surface de 316LVM est fortement dépendante sur le potentiel de surface. Lorsque le potentiel de surface augmente, les valeurs de plus en plus négatives, le taux d‟adsorption initiale de BSA ainsique sa …  Read more

The design of subsurface structures associated with transportation and other underground facilities, such as buried pipes and culverts, requires an understanding of soil-structure interaction. These structures are usually subjected to heavy loads from the backfill material in addition to substantial traffic loads, particularly when the structure is buried at shallow depth below ground surface. The soil-structure interaction of these systems depend on several factors including the method of construction and the relative stiffness between the structure and the surrounding backfill material. To reduce earth pressure acting on buried structures, different techniques have been proposed by researchers including the installation of …  Read more

In this study, we address the factorization problem in the Hardy H('p) spaces, and provide a fast algorithm for its implementation with applications to some important engineering problems. The Thesis is presented in three autonomous papers. In the first paper we lay down the technical foundation of the new approach in the scalar case. First, the factorization problem is formulated in the H('p) spaces. A formulation with sufficient generality to encompass practically all such engineering problems. Necessary and sufficient conditions for the existence of the spectral factors are derived, and a characterization of the class of functions admitting a canonical …  Read more

The effects of various steroid hormones on human chorionic gonadotropin (hCG) production and placental viability were investigated using an explant culture model of human placenta. Placental hCG production was assessed using two different methods: (a) hCG concentrations in media recovered from cultures were measured by radioimmunoassay and (b) tissue levels of hCG in cultured placentae were determined immunohistochemically; both were evaluated before and after exposure to steroid hormones. In first trimester placentae, progesterone and dehydroepiandrosterone (DHEA) increased hCG concentrations both in collected medium and levels in cultured placentae. Estradiol increased the levels of hCG in tissues but not in media. …  Read more

As XML gains popularity as the standard data representation model, there is a need to store, retrieve and update XML data efficiently. McXml is a native XML database system that has been developed at McGill University and represents XML data as trees. McXML supports both read-only queries and six different kinds of update operations. To support concurrent access to documents in the McXML database, we propose a concurrency control protocol called LockX which applies locking to the nodes in the XML tree. LockX maximizes concurrency by considering the semantics of McXML's read and write operations in its design. We evaluate …  Read more

The present qualitative study examines the lived experiences of six first-generation NorthAfrican immigrant parents in QC who received services from the Direction of Youth Protection(DYP). Guided by a phenomenological approach, the primary data collection method was indepthinterviews. The data were coded and analyzed according to the research questions.The research resulted in four major themes that emerged from the stories shared by theparticipants: (a) child-protection from the parents' perspective; (b) parents' perception of DYPservices; (c) help and services received: expectations versus reality; and (d) partnerships withresources and bridging cultural distance. I analyzed these themes through the theoreticalframework of intersectionality and cultural …  Read more

Soixante pour cent de tous les agents anticancéreux en développement sont sous forme orale. Les agents anticancéreux oraux (AAO) sont aussi efficaces, moins invasifs, et plus faciles à prendre que leur équivalent intraveineux (IV). Cependant, comme les AAO sont administrés endehors des environnements cliniques supervisés, la responsabilité de leur gestion tombe sur les patients et les proches. Les personnes sur AAO ont des besoins distincts par rapport à celles sous traitement IV, tels que des rappels pour prendre les AAO, de l’information personnalisée et suivi des effets secondaires, ainsi que du soutien provenant de la pharmacie communautaire.L'adhésion aux médicaments est …  Read more

The province of the present study is a legal and geo-political inquiry into the status of the navigable air-space. The fundamental law of the status of the air-space was restated or reaffirmed in 1944 at Chicago by the Convention on International Civil Aviation. Article 1 of this convention provided that 'every state has complete and exclusive sovereignty over the air-space above its territory.' [...]  Read more

Aux cours de ces dernières décennies, la question du « fondamentalisme religieux » est devenue l'un des fils conducteurs de débats controversés et de plus en plus répandus au sujet de la modernité, la sécularisation et l'extrémisme, qu'ils soient de nature religieuse ou non. Historiquement, on peut retracer le concept de « fondamentalisme » jusqu'aux début du XXème siècle aux Etats-Unis. En revanche, l'utilisation de ce terme a évolué au cours du siècle pour cibler de plus en plus des mouvements appartenant à différentes traditions religieuses, notamment islamiques. En effet, après la révolution iranienne de 1979, le terme « fondamentalisme …  Read more

There is growing consensus that health-related quality of life (HRQL) outcomes are important for the allocation of scarce medical resources and for facilitating clinical decision-making. However, because most instruments of HRQL are self-report measures inappropriate conclusions may be drawn from studies that assess changes in HRQL over time or between groups. If the individuals evaluating themselves experience a response shift (defined as changes in their internalized standard of evaluating their level of functioning, in their values, or in their conceptualization of the target construct), then measures taken over time or between groups are no longer comparable. To date, response shift …  Read more

The main objectives of this prospective cohort study were to examine the construct and predictive validity of the STREAM, and estimating its responsiveness. Sixty three acute stroke patients were evaluated on the STREAM and other measures of impairment and disability during the first week post-stroke, four weeks later, and three months post-stroke. The results of the study showed that STREAM scores were associated with measures of impairment and disability, and could discriminate subjects based on Balance Scale and Barthel Index scores. Moreover, the STREAM during the first week post-stroke was found to be an independent predictor of discharge destination after …  Read more

This dissertation explores the relationship between uses of the Bangladeshi immigrant press in Montreal and the reinforcement of its readers' ethnic identity. The work is based on information gathered from two Bangladeshi newspapers published in Montreal---Probashbangla and Banglabarta . The study views ethnic identity as being perceived, enacted, and maintained symbolically through communication activities of ethnic group members. The Bangladeshi immigrant press is considered to be a major vehicle for its readers' perception of ethnic identity, and as a strong stimulus for its reinforcement. It is suggested that the nature and extent of use of the Bangladeshi immigrant press serves …  Read more

The basic research question this thesis addresses is how the secondary status of Bangladeshi women is reinforced through household labour. It is argued that gender relations and housework shape each other. To develop this, it examines the degree of participation of women in different areas of housework and family decisions. The thesis further explores whether the autonomy of women coming from the traditional Bangladeshi family set-up has increased as a result of their immigration to Canada and their exposure to Canadian family values. This is done by a comparison of the family experiences of Canadian and Bangladeshi women. Finally, it …  Read more

Electrical energy demand is likely to grow at a pace more than envisaged with the pen- etration of plug-in hybrid electric vehicles(PHEV) into the grid. In other to meet this demand more expensive generation methods may be invoked. A potentially less expensive alternative is the management of demand to meet available supply through active partici- pation of consumers. In order to do so the system operators needs to establish a framework that allows control of demand to achieve economic and system reliability purposes. This framework also provides information on the ability of users to provide curtailment with respect to varying …  Read more

A substrate structure rule to predict the enantioselectivity of Candida rugosa lipase (CRL) towards $ alpha$-substituted carboxylic acids is proposed. Lipase from Candida rugosa resolved methyl $ alpha$-substituted phenylacetates -5. These substrates were examined to understand the influence of steric and the electronic nature of the substituents at the chiral center on the enantioselectivity. Crude CRL was partially enantioselective towards substrates -3, and highly selective towards and, E $>$ 100. Partial purification of crude CRL by 2-propanol extraction and separation by an ion exchange chromatography, dramatically improved the enantioselectivity towards -3, E $>$ 100. One main lipase fraction, F$ sb{ …  Read more

This study introduces and investigates a general method for measuring the flow of granular material through orifices. During the last decade or so, the phenomenon of the mechanization of material handling in modern industry has developed into immense proportions. But the problem of the handling of granular material through orifices lies, obviously, at the very root of this tremendous development. The present study is an attempt to contribute to the solution of this problem. Laboratory investigations were conducted with Ottawa Sand, glass bins, sand-paper bins and circular orifices. The effect of head, diameter of bin, diameter of orifice, roughness of …  Read more

Cette thèse explore les défis associés à l’estimation de la position et de l’orientation relatives entre des robots, c’est-à-dire leur état relatif, en utilisant la radio à bande ultra-large (UWB). Une estimation précise de leur position et orientation relative est essentielle pour la coordination des robots dans une variété d’applications, telles que les missions de recherche et de sauvetage, l’exploration de l’environnement, ainsi que la surveillance et l’évitement des collisions. Les capteurs UWB, qui sont bons marchés et légers, permettent d’obtenir des mesures de distance entre des robots mobiles et des ancrages fixes situés à des endroits connus. Avec des …  Read more

The Belle II experiment at the KEK laboratory in Tsukuba, Japan is currently undergoing commissioning, with first physics data anticipated in 2018. Understanding the material distribution of detector components is of critical importance for precision e^+e^- collider experiments like Belle II, as the density and distribution of this material impacts tracking and vertex reconstruction, as well as other aspects of detector performance. Two complementary approaches undertaken to carry out material studies at Belle II are presented here. The first part involves a comparison of precise 2D images of the material profile of the vertex detectors, obtained using test beam experiments …  Read more

This thesis describes the search for a charged Higgs boson (H±) decaying to a pseudoscalar particle (A) and a W boson in top-quark pair events. The analysis selects events with one electron and two muons in the final state and three or more jets, at least one of which is b-tagged. The signal model considers an H± that is produced in top quark decays, while the A decays to muons. The mass range for the H± is between 100 GeV and 160 GeV, and that of the A is between 15 GeV and 75 GeV. This study uses 139 inverse …  Read more

Gravel, Simon (Internal/Cosupervisor2)  Read more

L'imagerie par résonance magnétique dynamique avec agent de contraste («Dynamic Contrast Enhanced Magnetic Resonance Imaging», ou DCE-MRI) permet la visualisation de la perfusion par l'acquisition de plusieurs images qui montrent le passage de contraste injecté lorsqu'il circule dans le système cardiovasculaire. Cette information est utile en oncologie parce que les tumeurs ont généralement une perfusion anormale. L'analyse quantitative de DCE-MRI exige un modèle mathématique qui décrit la cinétique du contraste. Dans cette thèse, un modèle existant est modifié pour obtenir une nouvelle version qui réduit le nombre de paramètres. Il est démontré par des simulation et sur données in-vivo que …  Read more

Background: Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) provides quantitative information on tissue blood supply by fitting a model to the acquired data. Conventional models require the arterial input function (AIF) which is difficult to measure.The reference region model (RRM) can quantify perfusion by using a reference tissue to circumvent the AIF.However, the RRM suffers from some major limitations: (i) it is only valid for simple tissues, (ii) it requires prior knowledge of the reference tissue parameters, and (iii) it requires a well-characterized healthy tissue, such as muscle, near the tissue of interest.Methods:Four advances were contributed to reference region modelling …  Read more

This thesis aims to build the groundwork for a distributed network of collaborating, intelligent video surveillance cameras. This work is implemented on a system of low-cost embedded-microprocessor-based camera modules. Each camera develops a person detection classifier using the Winnow algorithm for unsupervised, online learning. Training examples are automatically extracted and labelled from the current frame, and the classifier is then applied to the image to detect and locate person instances. To improve detection accuracy, multiple cameras with overlapping fields of view collaborate to confirm their results. We present a novel, unsupervised calibration technique that allows each camera module to understand …  Read more

It is a common practice to retrieve code from an outside source, execute it and return the result to the user. During execution secure data can enter the program by user input or access of a data resource. It is important to track the secure data once it enters the program to identify possible information flows to unwanted regions of the code which would permit undesirable data output to a user. Most approaches to restrict information flow in programs have fallen short of providing a practical solution for mainstream programming languages. To address this issue, this thesis presents two context-sensitive …  Read more

Drag reduction is beneficial in most fluid flow applications. In this thesis, the drag reduction potential of superhydrophobic surfaces fabricated by femtosecond (fs) laser micromachining is investigated under both internal and external flows. As fs laser material interaction is not well understood, its application for the fabrication of textured surface is studied in detail. New surface structures were fabricated on titanium, stainless steel, aluminum, and copper samples. The resulting structures were characterized, and the evolution of structure formation was mapped with two irradiation models, namely the fluence and pulse-per-spot (F-PPS) model and the accumulated fluence profile (AFP) model, consisting of …  Read more

Resistance responses of Abutilon theophrasti were investigated to determine defense mechanisms of the weed against Colletotrichum coccodes and to verify if some chemical suppression of the resistance mechanism could be exploited to enhance the virulence. Induced resistance in A. theophrasti has been confirmed in treatments with C. coccodes, benzothiadiazole, bentazon, and acifluorfen. Induction of peroxidase and phenylalanine ammonia lyase (PAL) activities in the leaves that did not contact with the inducing agents was observed after the localized stresses to the first leaf or the root of the plant with those agents. alpha-Amino-oxy acetic acid (AOA), 2-deoxy-D-glucose (DDG), mannose, oxalic acid, …  Read more

Enameling steel, used in a vast range of applications, can suffer from a surface defect resembling fish scale. In this study, the effects of several microstructural, physical and coating factors on the hydrogen diffusion in low carbon steel were investigated using an electrochemical permeation apparatus, to find out the way to prevent the surface defects on the enamel coatings. A new mechanism explaining the formation of the surface defects on the enameling steel was proposed after summarizing the experimental results. Then, the effects of porosity, dislocation density, the surface roughness of a steel substrate, oxide passive layer and Pd coating …  Read more

Whey media, containing 2% (w/v) whey powder, 1% (w/v) glucose, and 0.5% (w/v) yeast extract, were fermented with nine Lactobacillus strains to produce angiotensin I-converting enzyme (ACE) inhibitory peptides. Lb. brevis, Lb. helveticus, and Lb. paracasei were most effective in producing whey hydrolysates that contained potent ACE inhibitors, with the inhibition rate ranging from 93.3 +/- 0.3 to 100%. The hydrolysates of three Lactobacillus strains were partially purified by dialysis (6,000--8,000 Da cut-off) to remove larger molecules, and subsequently subjected to RP-HPLC, equipped with a Delta Pak C18 column. Each chromatogram displayed at least three distinct peaks at the hydrophobic …  Read more

The transferrin receptor (TfR) is a membrane protein whose function is to deliver transferrin-bound iron into the cell. Erythroid precursor cells and reticulocytes require huge amounts of iron for hemoglobin synthesis and express large numbers of TfRs. However, as the reticulocyte matures into an erythrocyte, TfRs are lost from the cell, as are a number of other membrane proteins. Nearly a decade ago, it was shown that TfRs are released from the sheep reticulocyte in vesicular form (in exosomes) during culture. Exosome formation may be the mechanism for remodelling of the plasma membrane during reticulocyte maturation. In this thesis, we …  Read more

Les signalisations par tyrosine kinases dans les cellules malignes sont essentielles pour la progression du cancer. Shc1, un régulateur critique et un point de convergence de la signalisation de la tyrosine kinase, a été ultérieurement montré comme favorisant la suppression immunitaire du cancer du sein. Cependant, le mécanisme moléculaire était inconnu. En combinant des modèles in vivo, des techniques de biologie cellulaire et de la bioinformatique, nous avons identifié des noyaux de signalisation de phospho-tyrosine spécifiques (Y239/240 ou Y313) de protéines adaptatrices Shc1 qui régulent des voies inflammatoires importantes, permettant finalement aux tumeurs d'échapper à la réponse immunitaire anti-tumorale. Nous …  Read more

Radiolabelling is the final and critical step in producing positron emission tomography (PET) radiotracers involving complex chemical reactions. To enhance production efficiency and minimize radiation exposure, the process has been broken downinto basic automated unit operations, executed within a synthesis module placed inside a hot cell. Within the synthesis module, radiation detectors play a key role by allowing the radiochemists to monitor radioactivity transfer across compartments and ensure the progression of reactions. However, these detectors come at a high cost per channel, motivating the need for more affordable alternatives. This thesis aims to develop a compact and cost-efficient detector using …  Read more

Emotions are multicomponent psychological constructs that are expressed in multiple channels, including through affect, physiological, and behavioural processes. While this conceptualization has been embraced in the field of traditional educational psychology, it is unclear whether such adoption is the norm in medical education. Such adoption and pursuit of investigating the emotions of learners is particularly important in understudied subject domains such as anti-harassment education. The importance stems from emotions’ role in fostering or hindering achievement, and therefore the need for researchers and educators to provide emotions-aware educational experience for learners. This dissertation identifies the current gaps in simulation-based education regarding …  Read more

Cette recherche entend contribuer à l'étude de l'hindouisme en diaspora. Elle s'appuie sur une documentation historique et un travail de terrain de caractère ethnographique. Elle est centrée sur l'évolution du culte de la divinité Mardévirin/Maduraivīraṉ entre l'Inde du Sud où il prend naissance et l'île Maurice, une des sociétés de plantation du XIXe siècle où l'a amené l'engagisme. Ma recherche m'a conduit à une étude parallèle de l'histoire culturelle des communautés pratiquant le culte de Mardévirin. J'ai d'abord replacé les origines de ce culte dans l'Inde précoloniale afin de pouvoir situer certains thèmes importants, tels que le symbolisme politique, l'ambiguïté …  Read more

Au Québec, fréquenter une institution scolaire ayant le français comme langue d’enseignement est une exigence pour une population grandissante d’élèves issus de l’immigration (OQLF, 2024). Les politiques linguistiques et interculturelles de la province placent l’usage et l’apprentissage du français au cœur de l’intégration sociale et scolaire des élèves issus de l’immigration plurilingues (EIIP) (Bouchard, 2012; MCCIQ, 1990; MEQ, 1998). Ces politiques limitent l’utilisation de l’ensemble du répertoire linguistique des EIIP à l’école, ce qui va à l’encontre de la recherche qui démontre que de telles pratiques peuvent être bénéfiques pour les apprenants de minorités linguistiques sur les plans scolaire et …  Read more

Cette étude de cas exploratoire traite des expériences et de la collaboration entre pairs liées à l'apprentissage du français de huit élèves du primaire issus de l'immigration (EII) dans une école de la région métropolitaine de Montréal. Les croyances et perceptions d'enseignants sont aussi analysées afin d'offrir un portrait détaillé des besoins et défis que vivent les participants dans ce contexte académique. Les résultats divulgués découlent d'entrevues avec les élèves, enseignants et parents, d'observations en classe ainsi que d'interactions entre pairs durant des activités de français. Ces différentes méthodes permettent de se renseigner sur les expériences d'apprentissage et d'enseignement du …  Read more

Guo, Jin (Supervisor1)  Read more