McGill University Thèses et mémoires publiés en 2016

Recent studies have demonstrated that multivariate machine learning algorithms can decode the orientation of grating stimuli from coarsely sampled (3×3×3 mm3) functional magnetic resonance imaging (fMRI) data. Unraveling the mechanisms underlying decoding of information conveyed in the fine scale cortical organization of orientation preference will enable informed search for other fine scale organizations in relatively unknown areas such as the frontal cortex. We therefore aimed to analyze the mechanisms underlying decoding of information conveyed by orientation columns and maps. To this end, we have analyzed contributions from four out of the six hypothesized mechanisms as candidate contributors to the decoding …  Lire la suite

Metrakos, Peter (Internal/Supervisor)  Lire la suite

In Caenorhabditis elegans, two mutations that affect mitochondrial electron transport chain subunits (isp-1 and nuo-6) result in increased mitochondrial reactive oxygen species (mtROS). These mutations cause a significant increase in lifespan relative to the wild type. Treatment with the pro-oxidant paraquat (PQ) can also significantly increase wild type lifespan, but is not additive to the lifespan of the two mutants. Using gene arrays, we determined a large overlap of differentially expressed genes between isp-1, nuo-6 and PQ treatment. These and other results are contrary the Free Radical Theory of aging and suggest that increased levels of mtROS act as a …  Lire la suite

Cette recherche examine Deutéro-Isaïe 42:14 et 49:15 pour démontrer que ces deux passages se réfèrent à une métaphore maternelle. La plupart des sources secondaires ont négligé l'aspect maternel de YHWH dans ces versets. Cette recherche réexamine les problèmes interprétifs et exégétiques qui ont été utilisés autrefois comme des arguments contre les aspects maternels de YHWH, tel que ce qui constitue comme une métaphore et comment les lieux communs associés peuvent affecter la langue de la maternité. En montrant que l'imagerie maternelle est attribué à YHWH, cette recherche met en évidence l'importance de considérer YHWH comme comme étant imagé dans les …  Lire la suite

Hatami, Hamed (Supervisor2)  Lire la suite

Wheat (Triticum spp.) is the third most produced cereal crop, being planted on more than one sixth of global cultivated farmlands, and providing 40% of world grain production. Numerous biotic and abiotic challenges can limit its production. Mycorrhizal-colonization of roots is a promising approach for mitigating stresses, has been studied in different plants (ex. rice, pepper, citrus, etc.) and has proven to be beneficial in aspects such as: increasing water absorption, enhancing mineral uptake and improving abiotic stress tolerance. Studies on this mutualistic relationship have been limited in wheat and information regarding alternation of antioxidant capacity of various wheat grain …  Lire la suite

The androgen receptor (AR) serves as a key driver of the proliferation and survival of prostate cancer (PCa) cells. Current mainstay treatment is to block the AR signaling by androgen deprivation therapy and antiandrogens. Despite the short-term efficacy of suppressing AR signaling, the tumor eventually adapts resistance via constitutive activation of the AR axis and manifests in the form of castration-resistant prostate cancer (CRPC). So far, multiple molecular mechanisms behind castration-resistance have been reported, including persisted androgen synthesis, AR amplification, AR point mutation, AR splice variants and AR transcriptional co-regulators. Unfortunately, current AR-targeting agents are unable to prevent AR reactivation, …  Lire la suite

Chen, Linan (Internal/Cosupervisor2)  Lire la suite

Les fragments de code (petite portion réutilisable de code source) sont d'importantes ressources afin de comprendre les interfaces de programmation (API) de bibliothèques logicielles. Dans plusieurs scénarios d'utilisation de fragments de code, ils doivent être réduient à l'essentiel. Par exemple, lorsqu'il servent d'indices pour de plus longs programmes, afin de rappeler aux développeurs des idiomes qu'ils connaissent déjà ou encore pour afficher des résultats de recherche. Cette dissertation fait un compte-rendu de la recherche sur la réduction, ou la synthèse, des fragments de code, et apporte trois principales contributions : L'étude de cas sur la génération de résumé de fragments …  Lire la suite

Gene-by-environment interactions influence brain development from conception to adulthood. In particular, prenatal brain development is a window of vulnerability to the interplay between environmental and genetic factors. Rodent and human research demonstrates that prenatal maternal stress (PNMS) alters hippocampal volumes. In Project Ice Storm, it has been demonstrated that increased levels of objective, but not subjective, PNMS are associated with increased right hippocampal volumes in early adolescent females. However, although PNMS affects hippocampal size on average, similar degrees of PNMS lead to different effects in different individuals. This differential susceptibility to the effects of PNMS may be due to genetic …  Lire la suite

La migration cellulaire est un processus hautement intégré et fondamental à de nombreuses fonctions biologiques passant par le développement, la réponse immunitaire et la cicatrisation des plaies, ainsi que la métastase dans le cancer. À fin de migrer, les cellules doivent générer et transduire des forces de traction à leur environnement. Cependant, aucune technologie à ce jour a fourni une solution à haut débit pour mesurer ces forces de traction.Je présente ici une nouvelle méthode analytique pour mesurer les forces contractiles cellulaires utilisant des plaques de culture multi-puits et robustes: En utilisant un format de plaque à 96 puits, des …  Lire la suite

It has long been recognized that egg-based manufacturing is an important limitation of current influenza vaccine production. In particular, this platform cannot meet the surge requirements in the event of an emerging virus. There is therefore a strong impetus to develop updated technologies that do not rely on traditional manufacturing processes. Medicago Inc. has developed a highly efficient platform to produce influenza virus-like particles (VLPs) in plants that can produce a candidate vaccine in three weeks, once sequence information is released. Although the company has both seasonal and pandemic vaccines based on the hemagglutinin (HA) protein in advanced clinical trials, …  Lire la suite

Chez la drosophile, le développement de la jonction neuromusculaire dépend d'une signalisation rétrograde d'élément musculaire vers la terminaison présynaptique des motoneurones. Le ligand de BMP (Bone Morphogenic Protein), libérée par la cellule musculaire post-synaptique, induits une signalisation rétrograde impliquant la phosphorylation et la translocation au noyau du facteur de transcription Mad dans le neuron présynaptique. Nous avons démontré récemment que l'accumulation normale de Mad est régulée par la kinase Nemo (Nmo) agissant sur un site distinct que celui pour du récepteur à la BMP. Des mutants de la Nmo induisent des changements de structures de la synapse sans moduler l'efficacité …  Lire la suite

Identifying the mechanism(s) of interaction of nanoparticles (NPs) with cell membranes is key to understanding their potential cytotoxicity and their biomedical applications such as nano-carriers for targeted drug delivery, cancer therapy and bioimaging. Cell membranes are a complex matrix of biomolecules; they are very difficult to isolate and manipulate for systematic studies with NPs. Given the fact that the mechanical and physicochemical properties of cell membranes are mostly determined by the abundant phospholipids of the membrane, supported phospholipid bilayers (SPBs) are commonly used as simplified models of cell membranes. However, SPBs are soft thin films, and, as such, their properties …  Lire la suite

Les salmonelles sont responsables de diverses maladies allant de la simple gastroentérite aux formes plus graves telles que la fièvre typhoïde. Les infections à Salmonella empruntent généralement la voie digestive et posent un problème de santé publique dans des régions du monde où il y a peu d'accès à l'eau potable. La sensibilité de l'hôte dans la réponse à l'infection peut s'expliquer par plusieurs facteurs localisés à l'interface de l'interaction hôte (gènes de prédisposition), pathogène (dose infectante, virulence) et environnement. L'utilisation du modèle murin par approche génétique a permis de mieux comprendre la physiopathologie des infections à salmonelles. Chez la …  Lire la suite

Beverlea K Tallant (Supervisor2)  Lire la suite

Institutions, defined as rules, norms and strategies, play an important role in shaping socio-ecological interactions and determining human behavior. In Quebec, agro-environmental policies were introduced within the last 15 years to reduce the degrading effects of intensive agricultural production on land and water. However, the disturbance of water ecosystems remains a problem in agricultural areas in part due to producers' difficulties in complying with the present agro-environmental regulation. This research assesses the role of institutions in encouraging the compliance of hog farmers with Quebec's Règlement sur les exploitations agricoles (REA) in the Missiquoi Bay. This regulation is meant to reduce …  Lire la suite

This thesis presents a convolutional neural network (CNN) based approach for detection and segmentation of Multiple Sclerosis lesions in brain magnetic resonance imaging (MRI). Automated pathology segmentation was presented in literature, starting from the early 1990s, and although reported to be a challenging task, could be highly beneficial for clinical trials labeling where large amounts of images are at hand. Robust detection of such pathology is still an open problem, and is prone to variabilities in: image non-uniformity, intensity distributions, acquisition artifacts, brain-structures, patients, scanners, configurations and sites. A CNN-based approach is proposed due to its recently reported high quality …  Lire la suite

A common and well-accepted green vegetable, broccoli (Brassica oleracea L.) plays a significant role in both domestic and international markets. While rich in nutritional compounds, it is difficult to preserve. When dealing with broccoli spoilage issues in Quebec and elsewhere, drying presents a method to extend the shelf life of broccoli. A brief review of drying is followed by a more specific discussion and experimental investigation of broccoli's drying behavior under both hot air and microwave-assisted drying. The results of this investigation served to formulate practical recommendations for the vegetable processing industry.The drying kinetics under different conditions were determined. Overall …  Lire la suite

Luis, Miranda-Moreno, (Supervisor1)  Lire la suite

Rappaport, Jamie M (Internal/Cosupervisor2)  Lire la suite

Background and Aim: Fibrillins are the major components of microfibrils in the extracellular matrix of elastic and non-elastic tissues. They are multi-domain proteins, containing mainly calcium-binding epidermal growth factor-like domains and 8-cysteine/TB domains. Fibrillin-1 contains one evolutionarily conserved Arg-Gly-Asp (RGD) sequence in its fourth TB domain which is required to mediate cell-matrix interactions by binding to cell-surface integrins. Mutations in this domain lead to heritable disorders, including Marfan syndrome and stiff skin syndrome. This study aims to determine the cell signaling function of the fibrillin-1 RGD sequence in regard to microRNA (miRNA)-dependent gene regulation.Experimental Procedures: Two recombinant fibrillin-1 fragments were …  Lire la suite

Protein synthesis is indispensible for cells to execute various functions such as proliferation, survival and development. The majority of mRNAs in eukaryotic cells are translated in a cap-dependent manner, which is dependent on the activity of the rate-limiting component known as the eukaryotic translation initiation factor eIF4E. eIF4E is overexpressed in a variety of human malignancies including breast, prostate, and lymphomas, but the role of eIF4E in the biology of melanoma remains elusive. The overarching hypothesis for this thesis work is that eIF4E promotes cell survival and facilitates acquired resistance to therapeutic inhibitors in human melanoma. We assessed eIF4E expression …  Lire la suite

Marco, Fossati, (Supervisor2)  Lire la suite

Asgharian-Dastenaei, Masoud (Internal/Supervisor)  Lire la suite

La cure précoce de la carbonatation des produits préfabriqués en béton accélère la résistance initiale et permet de promouvoir l'utilisation du dioxide de carbone. Le béton armé représante la majorité des produits de béton préfabriqués, ainsi, l'application de la technologie de de la carbonatation précoce sur la cure du béton armé est capable d'améliorer le potential d'utlisation du dioxyde de carbone par les produits fabriqués en béton pour la réduction des émissions et l'amélioration de la péreformance. Cette thèse vise a développer un processus spécial de cabonatation adapté à l'affaissement du béton préfabriqué. Le fonctionnement du béton composé de ciment …  Lire la suite

Molecular oxygen plays an important role in the metabolic activities of aerobic cells, it is essential for oxidative phosphorylation, which produces the most energy for cell activities. Oxygen shortage, i.e. hypoxia, induces adverse cellular events, such as increased glycolysis, cell apoptosis, and even necrosis. However, hypoxia and even anoxia (absence of oxygen) often occur during tissue engineering, organ preservation, and wound healing, due to the low solubility and limited effective diffusion distance of oxygen in water, a lack of or compromised oxygen supply by blood vessels. Various approaches and materials have been developed to deliver oxygen to tissues and cells, …  Lire la suite

Majewski, Jacek (Supervisor1)  Lire la suite

Efflorescence is a salt deposit which is formed on or near the surface of a porous material such as Portland cement concrete. Although efflorescence is not an indication of internal damage, it alters the aesthetic quality of the product. The primary goal of this work was to investigate whether early-age carbonation can help reduce, or altogether eliminate, efflorescence formation on concrete paver blocks. The devised carbonation technique involved curing concrete pavers in a chamber filled with either pure or 20% carbon dioxide gas under a pressure of 5 bar. The carbonated pavers were evaluated by a newly developed test method …  Lire la suite

Meeting food demand for ever increasing global population can be attained through sustainable management of soil resources. This requires a thorough understanding of soil properties and processes and calls for methods to quantify and display spatial variability of soil. Three dimensional digital soil mapping (3D-DSM) with its ability to quantify both the horizontal and the vertical variability has become popular in recent days. The state-of-the-art data mining techniques including 3D regression kriging (RK) has been used to uncover complex soil-landscape relationships but not assessed at small scales. In addition, recent advances in proximal soil sensing allow measurement and prediction of …  Lire la suite

Tourism, which the Chinese state advocates as a vehicle for modernization and poverty alleviation, has been established in Dali Prefecture, Yunnan Province, since the mid-1980s. Building upon scholarly literature on cultural tourism and sustainable livelihoods, this thesis examines the growth and structure of the cultural tourism sector in Dali and its impacts on Bai culture and livelihoods over three generations. I completed fieldwork during May–August 2014 in Dali City, the prefecture's main tourist destination, employing five qualitative research methods: participant observation, unstructured interviews, semi-structured interviews, oral histories, and Photovoice. My results point to certain negative impacts of cultural tourism growth …  Lire la suite

Les objets tels que les arbres, arbustes et herbes hautes sont composés de milliers de petites surfaces distribuées dans un volume 3D. Une tâche visuelle naturelle est d'estimer la profondeur des objets dans une scène encombrée de surfaces en désordre. Par exemple, un humain peut estimer la distance d'un prédateur ou d'une proie, et peut décider si un fruit, parmi le feuillage, est accessible. Pour estimer la profondeur dans un fouillis 3D, un système visuel peut utiliser la disparité binoculaire et des mouvement parallaxes, mais ces indices de profondeur sont moins fiables dans un fouillis 3D parce que les surfaces …  Lire la suite

Phenomena related to the spin degree of freedom of electrons are an important aspect in material physics. They can play significant roles in both magnetic and nonmagnetic materials. It is thus desirable to have a material simulation tool that is capable of computing spin related quantities from first principles. In this thesis we report our implementation of spin related calculations in the RESCU real-space DFT code[2], including collinear and noncollinear spin-polarized calculations, and spin-orbit coupling (SOC) calculation. The main eigensolver of RESCU is based on the Chebyshev-filtered subspace iteration method proposed in Ref.[3]. In this work the filter operator is …  Lire la suite

Les séparateurs a gravité améliorer, ou centrifuge, ont révolutionné le traitement de l'or au cours des dernières décades, augmentant significativement la récupération de l'or natif fin (-106 µm). Le concentrateur Knelson, un des concentrateurs centrifuges les plus couramment utilisé, est devenu l'unité prédominante pour la récupération de l'or primaire par gravité. Cependant, son potentiel d'application a des limites. L'un des principaux inconvénients du concentrateur Knelson est le grand volume d'eau requis. Tandis que l'eau est transformée d'une «marchandise» toujours plus importante, la réduction de la consommation d'eau est d'une grande importance, à partir d'environnement et d'un point de vue financier. …  Lire la suite

Liu, Xue (Supervisor1)  Lire la suite

Integer least squares (ILS) is an important class of optimization problems, which can arise in many applications, such as communications, cryptography and cryptanalysis and global navigation satellite systems. This thesis is concerned with solving the underdetermined box constrained ILS (UBILS) problems. For the two existing algorithms, the direct tree search (DTS) algorithm and the partial regularization (PR) algorithm, we propose to incorporate some lower bounds to speed up the search process. Simulation results show that the proposed lower bounds can make the search process of the DTS algorithm perform more efficiently than the original one. Then we propose a modified …  Lire la suite

« 5 to 9 » est une composition musicale se penchant sur le concept de « interval wedge »—un système où l'ordre des hauteurs est mise en ordre à l'aide d'une extension ou d'une compression intervallique––et son utilisation dans la forme, la mise en place motivique, le rythme, le timbre, l'orchestration et le tension dramatique. Ces compensations sont communes dans le canon de la musique occidentale en tant que outil sonore: cependant prise tel un processus strict de conduit des voix, cette procedure utilisant l'augmentation et la diminution intervallique n'a pas encore été explorée ou analysée de manière exhaustive en …  Lire la suite