McGill University Theses and dissertations published in 2013

Collin, Rachel (Supervisor2)  Read more

Childhood blindness due to hereditary retinal disease represents a huge clinical problem. Morbidity, blindness but also a major lack of understanding the molecular genetic events that lead to blindness in very young children hamper clinical management of this important and common problem. One way to get entry into the disease mechanism of childhood retinal blindness is to study Mendelian disease entities that are caused by relatively straightforward links between mutations in genes that lead to aberrant retinal protein function and the resulting disease phenotype. These discoveries in the Mendelian model would lead to understanding of the genetics, proteomics and most …  Read more

La présente thèse aborde le développement d'une nouvelle analyse et technique de recherche pour des resonances massives dans les distributions angulaires des états finaux dits photon+jet parmi les données récoltées en 2012 parle détecteur ATLAS du LHC. Une nouvelle variable angulaire développée sur mesure pour le canal photon+jet a d'ailleurs été définie afin de pouvoir distinguer le bruit de fond du signal plus efficacement. La sensitivité de cette observable a été optimisée en utilisant des échantillons Monte Carlo de quarks excités ainsi que du programme JetPhox. Une classification optimale en terme de masse a aussi été dérivée à partir de …  Read more

Habashi, Wagdi George (Supervisor2)  Read more

Voice problems often involve physical injury and they have serious emotional, functional and economic consequences. The present research project contributes to the development of an injectable biomaterial for potential use in treating vocal fold (VF) lamina propria (LP) scarring disorder. A new biomimetic hydrogel system, based on hyaluronic acid (HA) and gelatin (Ge), with hierarchical structural organization was designed, characterized, and evaluated in vitro and in vivo. This hierarchical composite hydrogel was constituted from hybrid HA–Ge microgels, fabricated through water-in-oil mini-emulsification polymerization, embedded in a secondary HA network. Experiments were performed to investigate the suitability of such hierarchical network for …  Read more

Gupta, Indra (Internal/Cosupervisor2)  Read more

Afin d'étudier l'effet de la digestion sur la structure et la fonction des polyphenols, les études in vitro qui reproduisent les conditions enzymatiques et chimiques de l'estomac et de l'intestin grêle sont utilisées. Malheureusement, la majorité de ces études, ne prennent pas en compte l'effet de la microflore intestinale. Le Modèle gastro-intestinal humain dynamique contrôlé par ordinateur (modèle GI) est composé de cinq récipients/bioréacteurs qui représentent respectivement les compartiments du système digestif humain: l'estomac, l'intestin grêle, le côlon ascendant, le côlon transverse, et le côlon descendant. Le bute de cette thèse était d'évaluer le changement du profil polyphénolique et de …  Read more

The stringent response (SR) is a conserved bacterial stress response mechanism that allows bacteria to survive during stress and starvation. This response is mediated by (p)ppGpp, a hyperphosphorylated guanosine signal that regulates expression of genes to inhibit cellular proliferation and induce genes important for survival and adaptation. This study investigates the role of the SR in regulating oxidative stress pathways in Pseudomonas aeruginosa (PA), a human opportunistic pathogen that can cause infections in immunocompromised patients, and patients suffering from cystic fibrosis. Our results demonstrate that inactivation of the SR significantly increased susceptibility to killing by multiple oxidants, impaired anti-oxidant defenses, …  Read more

Energy-awareness is an urgent need to tackle the challenges raised by the high demands of wireless traffic and energy consumption, and orthogonal frequency division multiplexing (OFDM) is a multi-carrier modulation technique that has been widely used in broadband wireless systems in order to mitigate the adverse impacts of frequency-selective fading. In this thesis, we consider the problem of energy-aware resource allocation in a downlink (DL) transmission scenario of multi-user OFDM systems. At first, an optimal and fast resource allocation algorithm is proposed for maximizing the energy efficiency (EE) of a DL multi-user OFDM system subject to a constraint on the …  Read more

Chmura, Gail L. (Internal/Supervisor)  Read more

Recent years have seen a huge growth in the demand for online virtual worlds. The type of these online systems can range from virtual meeting setups, to a more video game like competitive environment. An equally large number of virtual worlds have been developed to meet this demand, and the competition between these system is very strong. Developers of such systems can benefit from any edge they can get in terms of technical quality of the system or the enjoy ability of the online experience.We propose that a monitoring system designed especially for virtual worlds will be able to provide …  Read more

This thesis examines the experiences of the first wave of Pakistani immigrants to arrive in Canada after the immigration reforms of the 1960s and 1970s. It focuses largely on the Pakistani community in Toronto. Its primary thesis is that while the immigration reforms and accompanying national policy of multiculturalism of this era were intended to foster democratic, humanitarian, and egalitarian principles, Pakistanis, like other immigrants of colour, actually saw their efforts to join the social and economic mainstream thwarted by discrimination both at the hands of government officials and within Canadian society. The thesis makes extensive use of a wide …  Read more

Les gouttelettes lipidiques (GL) sont des organites phylogénétiquement conservées et impliquées dans plusieurs fonctions cellulaires. Durant les deux dernières décennies, notre compréhension des rôles biologiques et physiologiques des GL a augmenté de manière draconienne. Plusieurs observations suggèrent fortement que les GL jouent un rôle important dans l'inflammation, ainsi que dans les désordres métaboliques tels que le diabète de type 2 (DT2). Malgré cette avancée, plusieurs aspects de la biologie des GL et de leurs rôles dans des maladies demeurent méconnus.Le centre des GL est riche en lipides neutres qui peuvent se mobiliser et servir comme source d'énergie. La couche phospholipidique …  Read more

Evans, Michael (Internal/Cosupervisor2)  Read more

Toutes les cellules vivantes, selon leur fonctions physiologiques, sont soumises à différentes stimulations mécaniques. L'ampleur et la fréquence de ces stimulations mécaniques varies considérablement d'un organe à un autre. Les stimulations oscillantes dues notamment à la marche, la respiration et la circulation sanguine sont largement étudiées. Par contre, les travaux concernant les stimulations a très faibles fréquences sont rare. Cette recherche examine les effets sur différents types de molécules, des stimulations mécaniques à relativement basse fréquence, à l'échelle moléculaire. Tout au long du travail présenté ici, l'accent a été mis sur la différenciation des cellules souches et la dedifférenciation des …  Read more

Dans cette recherche, le modele de transition γ-Rẽ<sub>θt</sub> est combine avec le modele de turbulence k-ω SST afin de predire la transition vers le regime turbulent et d'obtenir des formes aerodynamiques au frottement visqueux minimal. Nous presentons les modifications necessaires a l'amelioration de la robustesse du modele de transition et etudions la precision du modele pour une large gamme d'angles d'attaque et de nombres de Reynolds. Le modele de transition est utilise pour predire le point de transition, pour evaluer les mecanismes de transition ainsi que les differents effets relies au nombre de Reynolds, et pour etudier les caracteristiques et …  Read more

Bartlett-Esquilant, Gillian (Internal/Supervisor)  Read more

Les experiences traitant de la statique et de la dynamique d'une seule molecule d'ADN dans des systemes nanoconfines sont generalement effectuees par microscopie de fluorescence, donnant acces a l'information concernant la conformation moleculaire, mais aucune information directe concernant les forces a l'echelle nanometrique. Dans cette experience, nous combinons deux outils de manipulation d'une seule molecule, le piegeage optique et le nanoconfinement, an de developper un nouveau test pouvant donner des informations a la fois sur la conformation de la molecule et sur les forces subies en confinement. Des billes de polystyrene de 200nm sont piegees a l'interieur de nanocanaux de …  Read more

Les structures de gouvernance de la santé mondiale n'ont pas su répondre à la crise sanitaire mondiale à l'égard des maladies soient transmissibles ou non transmissibles. Je démontre que la gouvernance de la santé mondiale se caractérise par une approche à la santé de justice de marché et un manque de leadership en santé mondiale, comme en témoigne la négociation de règlements mondiaux sur la propriété intellectuelle et l'accès aux médicaments pour les maladies non transmissibles. Ceci soulève trois défis pour la santé mondiale: (i) aborder la question d'une large participation, (ii) l'affaiblissement du sens à donner à la santé …  Read more

La modification post-traductionnelles des protéines est un mécanisme cellulaire essentiel par laquel la structure et la fonction des protéines peuvent-être affectées. Les modifications sont présentes dans la grande majorité de voie cellulaire et les protéines cibles possèdent une grande diversité de fonction et de localisation cellulaire. L'acétylation des lysines a émergé comme une modification de grande importance, ayant un impact majeur sur les cellules, à l'instar de la phosphorylation. Effet, des études récentes de protéomique ont révélées que de 5 à 10 % des protéines bactériennes et animales étaient affectées par l'acétylation des lysines. Cette mondification est catalysé par l'effet …  Read more

Global climate change has been considered in many engineering studies due to its drastic impacts on the design and planning of various infrastructures. In order to reduce the risks of those impacts, the present study focuses on accurate prediction of daily temperature extremes for future periods under different climate change scenarios. The main objectives of this study are therefore: (a) to detect the evidences of climate change from the statistical analysis of existing observed daily extreme temperature data; (b) to assess the performance of single-site and multi-site statistical downscaling (SD) approaches in order to identify the best SD model that …  Read more

This study explores the perspectives and experiences of eleven adolescent girls in Cameroon on the meanings, purposes and barriers to education. Arts-based and visual methodologies are used to engage the girls in critical dialogue. A participatory approach gives value to the knowledge of local people as expertise and insight, which is often unknown to outsiders (NGOs, researchers, policy makers), in identifying issues specific to their own communities. With limited research done with girls, as opposed to on girls, this study seeks to hear the voices of girls, in-school and out-of-school, and make those voices heard in offering their inside-stories and …  Read more

Les systèmes de télécommunication futurs doivent supporter d’importants taux de débit de données afin de répondre à la demande croissante d’applications et contenus à grosse échelle dans le domaine du multimédia. Des systèmes de communication pratiques fonctionnent sur des canaux de communications à bande limitée en temps continu, transmettant des symboles sur ces canaux au taux de Nyquist qui est proportionnel à la largeur du spectre du canal. La transmission de la fréquence de Nyquist a traditionnellement été motivée par l'architecture simple de l’émetteur et du récepteur. Cette thèse explore les avantages de la transmission de données plus rapide que …  Read more

Histone deacetylase inhibitors (HDACi) are anti-cancer agents, which have shown promising activity in hematological malignancies. However, only a small percentage of patients initially respond to treatment and all will eventually develop resistance. HDACi are known to inhibit deacetylation of histones as well as various non-histone proteins. Revealing mechanisms of HDACi resistance will help elucidate their modes of action, as well as help overcome de novo and acquired resistance in the clinic. We chose to conduct our studies on vorinostat, which is a pan-HDACi and the first HDACi to be approved by the FDA for cancer treatment. To study HDACi resistance …  Read more

The Bowone and Binebase Au (Ag-Cu) deposits are related prospects, located 1 km apart on the volcanic island of Sangihe, Northeastern Indonesia. The deposits occur at the southern and oldest end of the island, and are hosted in Quaternary volcanic and volcaniclastic formations. Each deposit has a supergene and hypogene mineralized zone, although only the supergene zone of the Binebase deposit is of significant thickness. This thesis focuses on the hypogene zones of the deposits, and was undertaken with the goal of understanding the formation of high-sulphidation epithermal precious metal (Au, Ag) deposits. The hypogene mineralized zones at both Bowone …  Read more

Mannor, Shie (Supervisor2)  Read more

In the first chapter, the author examines the impact that companies have on human dignity. He states how human dignity as a concept is being consecrated in a multitude of international treaties, but notes the lack of definition surrounding this concept. Thus, he examines how the concept of human dignity has been defined in both the legal and philosophical terms. Then, the author explains how businesses by their actions directly impact on human dignity. He finds that this impact seems inevitable considering an inherent characteristic of companies the pursuit of profit. The author then concludes by stating the necessity of …  Read more

This dissertation examines a novel type of standardization in medicine by investigating the production and regulation of clinical practice guidelines. As an important tool of the Evidence Based Medicine (EBM) movement, guidelines have been at the center of polarized debates in which they are praised for rationalizing medicine and criticized for undermining humanism in health care. Based on document analysis, interviews and (participant) observation, this dissertation examines how 'evidence based' guideline developers respond to such contradictory demands and critiques. In doing so, I present an empirical examination of the way EBM practices construct, avoid or reconcile tensions between supposed binaries …  Read more

Le potentiel d'écoulement est due à la présence de charges fixes négatives sur les glycosaminoglycanes de la matrice extracellulaire du cartilage. Son évaluation arthroscopique peut potentiellement détecter les lésions localisées et fournir de l'information diagnostique quantitatif. La filtration d'électrolyte est également un phénomène découlant des glycosaminoglycanes. Généralement supposé négligeable malgré un manque de validation expérimentale, il peut être important pour la conception et l'interprétation des measurements du potentiel d'écoulement et pour le choix des suppositions de modélisation. L'objectif de cette thèse est donc de quantifier le phénomène de filtration d'électrolyte et d'estimer son effet sur les mesures de potentiel d'écoulement. …  Read more

L'appauvrissement des cellules B en périphérie est un traitement effectif chez les patients atteints de la SP et ce type cellulaire semblerait être un important médiateur lors des rechutes associés à la maladie. Toutefois, ils peuvent aussi induire les réactions inflammatoires compartimentées dans le SNC qui semblent être à la base des stades chroniques-progressifs de la maladie. La persistance des plasmocytes dans le SNC et les agrégations cellulaires riche en cellules B, cellules T et en cellules ressemblant aux CDFs dans les méninges des patients suggèrent que le SNC inflammé lors de la SP fonctionne comme étant un environnement favorisant …  Read more

In an industrial society it is critical that techniques be developed for the measurement of chemical species in the environment, in humans and as both intended and unintended products of manufacturing. Initially, these techniques were developed around sophisticated instruments and often involved complex procedures. It is obviously advantageous if the cost of analyses can be reduced and the experimental procedures simplified, while still maintaining the quality of the data collected. Furthermore, it is often desirable to have measurements performed rapidly, with on-site measurement sometimes deemed useful or even essential. All of these desirable outcomes may, in some cases, be obtained …  Read more

Les techniques de Matching Pursuit (MP) ont été considérées récemment pour le débruitage des signaux. L'algorithme MP peut reconstruire un signal pur à partir d'une observation bruyante à travers une estimation gloutonne (greedy) des moindres carrés (MC) comme une combinaison linéaire des éléments (atomes) d'un dictionnaire. Cette méthode de reconstruction évite les calculs intensifs de la solution de MC pour de larges problèmes, et elle exhibe une performance améliorée pour enlever du bruit, particulièrement dans le cas où le signal est creux. L'algorithme MP original et d'autres algorithmes de type MP, comme Orthogonal Matching Pursuit (OMP), résolvent itérativement le problème …  Read more

Les protestations sociales et les « révolutions électorales » sont des actions collectives qui se caractérisent par des processus de mobilisation. Ces évènements politiques complexes sont fréquemment à l'origine de résultats inattendus comme le déclanchement de la participation en masse qui provoque une action décisive. La diffusion d'information et l'appel à l'action collective sont des facteurs clés dans ce processus qui sont facilités par des connections au réseau d'activistes. L'étude systématique de ces mécanismes peut contribuer à repérer le point de basculement de l'action collective. Celle-ci est souvent atteinte lorsque des événements à plus petite échelle sont liés et déclenchent …  Read more

Adverse drug reactions (ADRs) present heavy burdens for the public health care system, and current pharmacovigilance activities are challenged by the under-reporting of ADRs in spontaneous reporting systems and a lack of incentive for industry to conduct rigorous post-approval research. As part of a new lifecycle approach to drug regulation, Health Canada recently announced plans to develop a new health product vigilance framework that will allocate drug safety resources using prioritization schemes focused on higher risk. These plans include the development of official policy requirements for industry to submit formal Risk Management Plans to Health Canada. This thesis argues that …  Read more

This thesis examined the Simple View of Reading (SVR; Hoover & Gough, 1990) in predicting writing performance. Specifically, the present study measured whether unique variance is explained by both decoding and language-related variables in predicting sixth-grade writing performance. The contribution of working memory in predicting writing was also examined, guided by the multi-component model of working memory (Baddeley, 2000). This thesis looked at the intra- and cross-linguistic prediction of these variables in English and French writing from the fall and spring of kindergarten, and the end of grade 1. This thesis does not offer support for the use of the …  Read more

Gait stability is perhaps the most important characteristic of locomotion. Maintaining gait stability poses a great challenge for the motor system since walking is a dynamical state and hence inherently non-stable. This challenge is greater in older adults and especially in post-stroke individuals, populations with increased fall risk. Despite its importance, gait stability is defined and quantified differently in different studies. Some studies measure coordination implying that more coordinated gait is also more stable. Finally, conflicting evidence relates gait stability with gait speed in different populations. The overall objective of this thesis was to evaluate the effect of aging and …  Read more

This thesis describes our advances in the preparation of lipophilic fluorogenic probes for the specific imaging of reactive oxygen species (ROS) in the lipid membrane of live cells. The work revolves around a simple design involving the preparation of a two segment receptor-reporter type free radical scavenger-fluorophore probe (an off-on fluorogenic antioxidant indicator). The receptor segment in the probe mimics the structure and activity of the naturally occurring antioxidant α-tocopherol. A covalently tethered lipophilic fluorophore serves the purpose of reporting, via emission enhancement, structural changes at the receptor end following its reaction with free radicals.In this thesis we initially explore …  Read more

The original goal was to use a downcomer to create swarms of solvent-coated bubbles to scale-up the air-assisted solvent extraction (AASX) process. The downcomer provides a close-packed bubble bed considered attractive for solvent coating and fast extraction kinetics. During initial testing, the bubble bed was observed to collapse upon introduction of solvent, evident from decreasing gas holdup, decreasing aspirated air rate, and formation of air slugs. Neither changing solvent introduction technique, solvent composition nor addition of frother or salt alleviated the situation. In many cases collapse was complete (air rate became zero) at less than 900 ppm solvent. Thus, the …  Read more

Background Temporal lobe epilepsy (TLE) is the most common drug-resistant epilepsy in adults. Hippocampal sclerosis, the hallmark epileptogenic lesion of TLE, is characterized by neuronal loss and gliosis. The hippocampus is composed of cytoarchitechtonically distinct subfields which are differentially affected in TLE. Indeed, neuronal loss is observed primarily in the CA1 and to a lesser degree in the subiculum, CA3, CA4 and dentate gyrus. Purpose. Our goal was to develop an anatomy-driven manual hippocampal subfield segmentation protocol on sub-millimetric MRI. We applied this protocol to TLE patients and controls to assess group-wise and individual differences in subfield volumes. Methods. We …  Read more

Introduction: Le cancer de la bouche est l'un des cancers les plus répandus dans le monde. Ses principaux facteurs de risque sont le tabagisme, la consommation d'alcool, et les infections au VPH ; et en Inde le chiquage de bétel, la consommation de beedi à fumer, et de tabac sans fumée. L'Inde a la plus forte incidence de cancer de la bouche dans le monde, avec plus de 69000 nouveaux cassignalés chaque année. Bien que des études récentes aient montré une association entre une mauvaise santé parodontale et le cancer de la bouche, aucune étude n'a évalué cette association dans …  Read more

Arsenic trioxide (ATO) is an effective treatment for acute promyelocytic leukemia (APL). While it is undergoing clinical trials for numerous malignancies including multiple myeloma, myelodysplastic syndrome, lymphoma and solid tumors, it has demonstrated only limited efficacy as a single agent. However, it may hold promise as part of a combination therapy. Thus investigation to elucidate the mechanisms of action underlying these clinical responses may lead to generation of rational combination therapies to increase its therapeutic spectrum. Previous work has described a pathway required for ATO-induced apoptosis in APL cells involving the generation of reactive oxygen species (ROS), and the subsequent …  Read more

Using procedural narrative generation in video games provides a flexible way to extend gameplay and provide more depth to the game world at low cost to the developers. Current examples of narrative generation in commercial games, however, tend to be simplistic, resulting in repetitive and uninteresting stories. We approach these challenges and develop a system for narrative generation that uses a context-aware graph rewriting framework. We use a graph representation of the game world to create narratives which reflect and modify the current world state. These narratives are all validated to ensure that they are completable and we design a …  Read more

Baker, Don (Internal/Supervisor)  Read more

Cell death and inflammation are two central, tightly coupled, innate immune processes. The inflammasome triggers both in response to pathogens and tissue damage. This cytosolic signalling complex contributes to host-defence, tissue repair and inflammatory disease, but the factors governing inflammasome activity are poorly characterized. This thesis examines the function of inflammasome modulators in infection and immunity. Inflammasome activity is antagonized by caspase-12. In humans, caspase-12 expression is limited to populations in geographical locations that overlap with regions endemic for malaria. We found that caspase-12 dampens the inflammatory response to Plasmodium, the malaria-causing parasite, resulting in impaired parasite clearance, but protection …  Read more

The two rounds of cell division that constitute meiosis are a conserved process that generates the gametes required for sexual reproduction. Given the importance of this specialized cell division in forming new life it is imperative for meiotic cells to ensure that the homologous chromosomes (at meiosis I) and subsequently the sister chromatids (at meiosis II) are properly segregated to avoid aneuploidy and infertility. As a first step in this process the maternal and paternal chromosomes (the homologs) have to be able to recognize each other and align along their length (pairing). In many organisms this culminates in the formation …  Read more

Le suicide est un problème qui résulte de l'interaction entre plusieurs facteurs. Un de ces facteurs, l'adversité durant l'enfance se définissant par une histoire d'abus sexuel et/ou physique de même que par la négligence parentale, est un des facteurs de risque les plus importants en ce qui à trait à l'augmentation des risques de développer des comportements dépressifs et suicidaires à l'âge adulte. Or, si une histoire d'abus augmente les risques de dépression et de suicide, les mécanismes responsables de ces effets comportementaux demeurent néanmoins méconnus. De récentes avancées laissent présager que l'impact comportemental d'une histoire d'abus serait transmis par …  Read more

Bernatsky, Sasha (Internal/Supervisor)  Read more

Guichard, Frederic (Supervisor1)  Read more

This thesis focuses on two phenomena that have challenged private international law in the 1990s. Firstly, the Supreme Court of Canada initiated a major transformation of the field in order to fit the internationalisation of private relations in the XXIth century. Secondly, the number of private relationships in cyberspace dramatically increased, along with a perception that state borders – the main tool used in private international law to identify the applicable law and to assert jurisdiction – were increasingly permeable. Today, this perception seems to be aggravated by "global" technological innovations such as cloud computing ... or at least that …  Read more

Cette autoanalyse parcoure l'étude narrative de la violence sexuelle, le processus de déconstruction identitaire, et la (re)négociation. À l'aide de la théorie du féminisme de la troisième vague, je remets en question les étiquettes de 'victime' et de 'survivante' présentes dans les études existantes sur la violence sexuelle faite aux femmes. En tant que femme ayant vécu une expérience similaire, je présente une introspection de ce qui m'est arrivé.Cette narration mène inévitablement à la vulnérabilité, et ouvre la voie à l'introspection et à la (re)négociation de l'identité. Ces explications peuvent être garants d'épisodes marquants d'introspection et d'analyse sociale pour les …  Read more