McGill University Thèses et mémoires par auteur commençant par S

Coffee production in Costa Rica has brought prosperity to many small farmers, but conflicts of interest with the companies which process and market coffee are still a problem. In addition, producers and processors are plagued by the periodic market cycles of agricultural commodities. Various agencies have promoted cooperatives to help small farmers deal with these problems, but they often fail due to poor management and lack of participation. This thesis, a multi-layered study of coffee production, processing, and marketing, examines how household producers manage the constraints and opportunities posed by the international market, the Costa Rican state, and the coffee …  Lire la suite

The description of odour, frequent in Zola's work, has been little studied, most researchers having focused only on the visual description of this novelist. This dissertation, taking as its corpus Les Rougon-Macquart, explores this issue. The working hypothesis is that Zola reveals his impressionist tendencies in this type of description. The first chapter presents a brief history of the status of olfaction and description of odour in its philosophical, social as well as in literary context. The following chapter, after having defined a few concepts (notions from Hamon and Adam), presents the status of the description of odour in Zola's …  Lire la suite

Myelin-associated axon growth inhibitors such as Nogo and myelin-associated glycoprotein (MAG) play an important role in the failure of axon regeneration in the adult mammalian central nervous system (CNS). One strategy to neutralize these inhibitors is a vaccination approach using immunization with myelin in incomplete Freund's adjuvant (IFA). In the present study, I compared the effectiveness of (i) immunizing with recombinant MAG/Nogo versus myelin, (ii) different adjuvants (IFA vs Alum) and (iii) different immunization frequencies for their capacity to promote spinal cord regeneration in adult SJL/J mice. The length of axon regeneration was similar in all the groups studied. However …  Lire la suite

My aim is to demonstrate that professionals perceive they have a right to refuse to provide their services and are currently acting accordingly. This thesis explores whether a professional right to refuse services exists; if so, the limits of this right; and whether a professional 'right' to refuse services ought to exist and in what circumstances. This requires analysis of whether refusals to provide professional services might be considered unethical conduct according to existing codes of ethics and moral theories, unprofessional conduct within the norms of professional regulatory and disciplinary bodies, or illegal conduct according to Canadian law, in particular, …  Lire la suite

Humans have a remarkable capability to adapt and learn new things, including new motor skills. For example, one can learn to play a short sequence of musical notes by navigating one's fingers on a piano or a guitar. Often, motor skill learning involves a goal-directed pointing or reaching to a clearly-defined visual target, such as making a purchase using a touch screen. In cases such as swimming or skiing, however, visual information is often limited or occluded. In order to successfully learn the task, one has to rely primarily on somatosensory information to form sensory goals or targets, or in …  Lire la suite

The thermal treatment of Newtonian and non-Newtonian fluid food was modelled to permit the optimal continuous sterilization temperature to be found. This model was incorporated into a user-friendly, interactive program package. In the program the food residence time distribution function, based on an appropriate rheological model, is initially calculated. The average residence time to satisfy a minimal lethality requirement and the value of an objective function are then found at each of a number of temperatures. The destruction or development of various components such as nutrients, texture, flavour, and colour can be included in the objective function. The importance of …  Lire la suite

Livestock and poultry nutritionists have long realized the importance of rations containing protein from animal sources, for rapid growth and high hatchability. Recently it has been discovered that one of the values of animal proteins lies in their supply of vitamin-like growth factors, which are found to be lacking in plant proteins. [...]  Lire la suite

Ovarian functions are mainly regulated by complex interactions of gonadotropins, metabolic hormones and growth factors, which are mediated through signaling networks including PI3K/Akt/MTOR and MAPK signaling pathways. At the level of the ovary, granulosa/luteal cells are pivotal in integrating these signals to regulate follicular/corpus luteum functions. Most of functional evidence for ovarian MTOR and MAPK signaling in granulosa cells has come from in vitro studies. Recently a pharmacological inhibition model (MTOR) and a conditional knock out mice model (ERK1/2) showed that MTOR and MAPK pathways regulate ovulation, respectively. However, complete mechanistic processes of regulation by these pathways in the ovary …  Lire la suite

The purpose of this study was to determine whether certain non-musical components of a performance affect evaluator's performance quality ratings. Specifically, if there is an age at which point the presence of a music stand (i.e. an implied use of the score), the performers attractiveness, attire, stage behaviour and perceived level of accomplishment impacts performance ratings. Fourteen cellists were videotaped performing by memory, and then a second time with their music on a music stand, synchronizing their motions with the audio feedback from their first performance. The cellists and their performances were evaluated by 1024 individuals with no formal training …  Lire la suite

In this thesis, I examine how and why Black women writers, in England and in the US, use the Gothic landscape of haunted houses and haunted bodies, as well as the trope of the monstrous Other to engage with the trauma of slavery, racial discrimination, misogyny, sexuality, and identity. I examine the site of the haunted house, haunted bodies, and the figure of the vampire and vampiric consumption in Helen Oyeyemi’s White is for Witching, Octavia E. Butler’s Fledgling, and Tananarive Due’s The Good House. In all three novels, hauntings are connected to trauma and loss. Additionally, in The Good …  Lire la suite

The East, in general, and the Muslim countries, in particular, have yet to solve the problem of adaptation to the process of modernisation initiated by the Western Civilisation in its expansive phase. This modernisation is a multi-sided process. It relates to military technique, industrial methods, administrative patterns, intellectual thinking, religious and moral concepts; in short, to the whole way of living. No phase of life has remained untouched by the impact of Western Civilisation on the East.  Lire la suite

Meerovitch, E. (Supervisor)  Lire la suite

La consommation d'oxygène dépendant de l'acetoacetate requiert la présence simultanée du 2-oxoglutarate et du malate pour l'obtention de taux de respiration maximum. Dans ces conditions, nous avons observé que (i) Pi et arsenate étaient stimulatuers, (ii) parapyruvate et arsenite étaient inhibiteurs et que cette inhibition n'était pas renversée par l'ATP, et (iii) la formation de 14C02 à partir de 14C-acetoacetate n'était pas détectable. Des expériences avec des pyruvates marqués différemment suggèrent que l'effet décrit en (iii) résulte de l'efflux d'intermédiaires intramitochondriaux du cycle de l'acide citrique en contrepartie de l'entrée du malate ajouté. […]  Lire la suite

This study analyzes the Bangladesh Crisis by building upon previous works that have applied microeconomic theory to international relations. One of the most innovative lines of inquiry from the realist school is to study international relations through analogy with microeconomic theory. Although used to analyze conflict, war, and the workings of the international system, a strict application of microeconomic theory to interstate crises is rare. This thesis will endeavour to contribute to this linkage.  Lire la suite

Bedos, Christophe (Internal/Supervisor)  Lire la suite

Mycoplasma hominis se multiplie dons une culture de la lignée de cellules leucémiques de souris L5178Y et en provoque la lyse. La multiplication en milieu de culture est dépendente des cellules de souris et se manifeste après une diminution initiale d'unités formant une colonie. En sous-culture dans un milieu frais, les cellules leucémiques infectées amènent une multiplication de mycoplasmes sone perte de viabilité. L'inoculation de plus de 10^5 U.F.C. par ml couse un effet toxique sur les cellules L5178Y de même que la multiplication des mycoplasmas atteignant ce nombre, soit plus d'une U. F.C. par cellule, amène la lyse des …  Lire la suite

The poly (A)-binding protein (PABP) is an essential protein found in all eukaryotes and functions in mRNA metabolic and translational processes. Structurally, PABP consists of two distinct regions. The N-terminal half contains four RNA recognition motifs that bind to the poly (A)-tail of mRNA, while the C-terminal segment contains a unique peptide binding module referred to as the PABC domain. The function of this domain in PABP is to recruit proteins containing a very specific 'PAM-2' motif to the mRNP complex. Unique to metazoans, a PABC domain is also found in the hyperplastic discs tumor suppressor (HYD), which is an …  Lire la suite

A three-dimensional model of Methanobacterium thermoautotrophicum (M.t.) elongation factor-1A, (M.t.)EF1-A, was generated based on homologous crystal structures. The model shows that structural elements essential for binding guanine nucleotides are conserved. (M.t.)EF1-A protein was purified to homogeneity using a combination of immobilized metal ion affinity and HPLC size exclusion chromatography. The protein specifically binds to guanine nucleotides and exhibits nucleotide exchange rates that give values between 4.6 and 6.5 x 10-3 s-1. The solution structure of Methanobacterium thermoautotrophicum elongation factor-1Balpha, (M.t.)EF1-Balpha, was determined by NMR spectroscopy. Analysis of the structure reveals an alphabeta superfold that is commonly found in RNA binding …  Lire la suite

Infrastructure is the foundation and the basic framework which permits cities to function. However, there are significant infrastructure problems in North America. In cities across North America, the infrastructure is deteriorating. The efficiency of a community depends on the condition of its infrastructure. The health and welfare of the residents and the economy of a country requires an efficient and sound infrastructure. North America will not achieve prosperity if it allows its urban infrastructure to decay to the Developing World's levels. Increased new sources of revenue need to be explored by political officials to pay for the cost of upgrading …  Lire la suite

Many uses of process models have been suggested in the literature, such as process models can help in understanding a process or they can be used as a baseline for process improvement. However, there are few quantitative studies that have validated these uses. In this thesis, we describe one use of process models by demonstrating empirically how process models help in achieving common understanding of a process among the people associated with the process. Literature in management sciences prescribes achieving common understanding of the process as an essential element of an effective organization. To carry out our research, case study …  Lire la suite

In experimental asthma, allergen challenges cause airway structural changes, termed remodeling, including an increase in smooth muscle (SM) mass and goblet cell metaplasia. These changes are substantially mediated via the epidermal growth factor receptor (EGFR) and its axis of ligands. The causal relationship between remodeling and another key asthmatic feature, airway hyperresponsiveness (AHR) has not been clearly established. The first objective was to investigate the site of airway narrowing in response to a single allergen challenge. We used two approaches, a morphometric assessment and an analysis of respiratory mechanics, using the constant phase model to partition the site of responses. …  Lire la suite

Tufenkji, Nathalie (Internal/Cosupervisor2)  Lire la suite

Transplantation antigen was isolated in its soluble form by injecting ultrasonicated lymphoid tissue in rat using the principle of biological filtration. The effect of biologically filtered antigen was studied in localized graft-versus-host reaction (Elkins' reaction). It showed almost complete suppression of reaction. The mechanism of action is postulated with the historical review of the subject. It is suggested that soluble antigen or one that bypasses macrophages is capable of inducing tolerance and opens the possibility of selective immunosuppression.  Lire la suite

Naveen Eluru (Internal/Cosupervisor2)  Lire la suite

Social media such as Twitter have become an important method of communication, with potential opportunities for Natural Language Generation (NLG) to facilitate the generation of social media content. The presence of the URL in the short tweet is a strong signal that the tweet is functioning to help Twitter users decide whether to read the full article. We focus on the generation of these indicative tweets, which we define as tweets containing links to external web pages. Extractive summarization is the process of generating a summary of the text by choosing a subset of words from the text. Previous work …  Lire la suite

This qualitative case study describes and analyzes the educational identities of second generation Indo-Canadian high school males in British Columbia. I draw from post-traditionalist sociology for my theoretical framework. I conducted face-to-face individual interviews to develop a collective and individual understanding of the perceptions of seven Indo-Canadian teenage males from four cities in British Columbia. Results indicate that their educational and personal identities are constructed more in relation to their daily social interactions and less in relation to traditional Punjabi cultural norms. Results from the student interviews reveal that they negotiate their identities in relation to social interactions that are …  Lire la suite

In today's age, it is becoming increasingly important to quantify the effect of the uncertainty in electrical circuits.This uncertainty arises mainly due to difficulties in controlling the physical parameters of microelectronic devices in the process of fabrication.Traditionally, methods like Monte-Carlo have been used by the circuit designers.The challenge with the Monte-Carlo method is that it requires a large number of simulations for even a very small number of random parameters, which makes it computationally expensive.Polynomial Chaos paradigm offers a solution to compute the uncertainty using fewer system evaluations.However, as the number of stochastic parameters increases, the number of system evaluations …  Lire la suite

Mussbacher, Gunter (Supervisor1)  Lire la suite

Impacts of Geomagnetic storms on Trans-Canadian GridsInduced "dc" currents due to geomagnetic storms have caused power system blackouts and transformer damages in the past. Statistically, large geomagnetic storms follow a 10-11 year sunspot cycle, but geomagnetic disturbances with significant impacts can occur at any time. The geomagnetically induced currents (GIC) have wide range of detrimental effects on otherwise normal operation of power systems, communication systems, railway systems, and can cause oil and gas pipeline corrosion. This thesis presents a method of estimating the magnitudes of terrestrial voltages; which is based on solving the magnetic diffusion equation. The method predicts the …  Lire la suite

Strawberry cultivation is an important sector for the Québec horticulture industry in terms of revenue as it represents 47% of Canada’s total production. In Québec, strawberry producers face challenges such as shorter production periods and soilborne diseases that severely impact fruit production. To overcome existing challenges, day-neutral (DN) cultivars are increasingly grown in soilless media, which resulted in extended harvesting season and improved fruit yield. Despite the increasing use of DNs in Québec, very little work has been done on DN strawberry production under local conditions, thus, available information is very limited. In this project, we determined the effect of …  Lire la suite

I present a distributed vision system for testing and development of computer vision algorithms. The system's form follows a new approach to the construction of vision systems. Utilizing streaming video interconnects and distributed computer resources, the system provides researchers with sufficient processing power to run complex algorithms under real-time constraints. The system runs algorithms in a pipelined mariner, with data passed between functional units using streaming video protocols. DirectShow forms the basis for the system's processing block objects. Researchers can configure the system using functional units from a library of source, rendering, and transform processing blocks available on the system. …  Lire la suite

Long, Ngo Van (Internal/Cosupervisor2)  Lire la suite

Drying Doctor, a multiple technique simulator of the paper drying process, has been developed at the Pulp and Paper Research Centre, McGill University. This thesis examines the different approaches to the modeling of this process, provides a rigorous validation of the simulation program and demonstrates its utility with four containerboard machines of Norampac Inc. Several features differentiate this simulator from others. When heavy grades of paper are produced or when high intensity drying processes are used even with thin sheets, substantial thickness direction gradients of moisture content and temperature develop across the sheet, demonstrating the necessity of a fully microscale …  Lire la suite

Cette thèse aborde la question de la cognition du timbre musical du point de vue de la reconnaissance à court terme et de tâches de jugement de dissemblance. Quatre séries d'expériences indépendantes ont étudié en profondeur le rôle: a) de la similarité du timbre et parallèlement de la variabilité de la hauteur pour la mémorisation à court terme du timbre, b) de l'impact des catégories de sources sonores et de la familiarité des sons et des séquences de ceux-ci aussi bien sur la reconnaissance du timbre que sur les jugements de dissemblance et c) de l'expertise musicale des auditeurs et …  Lire la suite

More than one billion people worldwide rely on seafood as their main protein source, but all seafood is contaminated with the toxic chemical mercury (Hg) in its methylated form (MeHg). The main route of exposure to MeHg for humans is through seafood consumption. Dietary assessment tools are used to evaluate the related risks and benefits. A major assumption in estimating these risks is that 100% of MeHg ingested is absorbed, yet emerging evidence suggests otherwise. Our goal was to increase the understanding of human exposure to MeHg by studying the solubilization and absorption of this potent toxicant in the human …  Lire la suite

Ells, Carolyn (Internal/Cosupervisor2)  Lire la suite

Alors que le monde s’occupe des changements climatiques qui s'intensifient, les batteries lithium-ion ont émergé comme technologie dominante grâce à leur densité énergétique. Contrairement à la grande quantité de recherche et de développement pour les batteries lithium-ion qui concernent les véhicules électriques, le domaine des appareils médicaux implantables exige des caractéristiques bien différentes pour leurs matériaux en batterie. Donc pour ces batteries, l'anode la plus commune pour les véhicules électriques, le graphite, n'est pas adéquate à cause de ses problèmes de sécurité pendant le cyclage à grande vitesse. Pour ces raisons, Li4Ti5O12 (LTO) est souvent utilisée comme une anode sécuritaire …  Lire la suite

This exploratory study was designed to identify a range of variables distinguishing long-term unattached (LTU) from long-term committed (LTC) adults between the ages of 30 and 50. Specifically, it attempted to identify explanations for, and consequences of, long-term unattachment. LTU subjects selected were those who had not been in a committed, intimate relationship for eight or more years; LTC subjects selected were those who had been in a marital, or equivalent, relationship for eight or more years. The study was done in two parts. The preliminary study was qualitative and consisted of interviews of 14 subjects--seven LTUs and seven LTCs. …  Lire la suite

Les granites de type-A sont enrichis en éléments à champ électrostatique élevé (HFSE), tels que le Zr, le Nb et les terres rares (REE). Toutefois, les processus magmatiques qui contrôlent l’enrichissement inhabituel restent largement débattus. Le pluton de Strange Lake (1.24 Ga) dans la ‘Core Zone’ Paléoprotérozoïque de Québec-Labrador, fournit un exemple d'enrichissement extrême en HFSE dans un granite peralcalin de type-A. Dans cette étude, des échantillons non altérés provenant du centre du pluton ont été analysés pour leur composition en roche totale et minéralogique. Le granite hypersolvus contient un feldspath alcalin perthitique comme phase majeure précoce et une amphibole …  Lire la suite

Nous avons utilisé la méthode dite "sucrose gap" afin d'étudier les changements de potentiels au niveau des fibres-C du nerf vague chez le lapin. L'hyperpolarisation qui suit un potentiel d'action ou une bouffée de potentiels d'action consiste en deux composantes exponentielles, l'une lente, l'autre rapide. Seule la composante lente, sensible à la ouabaine ou au remplacement des anions isethionate par le chlore, résulte de l'action de la pompe électrogène sodium-potassium. L'amplitude et la durée de la composante rapide sont sensibles à la concentration extracellulaire de potassium et augmentent avec la fréquence et la durée des bouffées de potentiels d'action de …  Lire la suite

Diverses approches sont utilisées pour la cueillette des données dans enquêtes de santé: les questionnaires par la poste, par téléphone ou les entrevues à domicile. Une stratégie d'enquête commence par une des approches et peut par la suite inclure une seule ou les deux autres approches pour les procédures de rappel des non-répondants. Différentes stratégies furent comparées dans une région de Montréal qui comprenait des anglophones et des francophones. Les stratégies qui débutèrent par la poste ou le téléphone et qui furent suivies des deux autres approches, fournirent des taux de réponses aussi éléves que la stratégie "domiciles" pour moitié …  Lire la suite

Pour survivre, les animaux interagissent avec leur environnement en recherchant les stimuli bénéfiques et en éludant ceux nuisibles; les émotions positives et négatives favorisent l’approche des premiers et l’évitement des seconds. Traiter l’information concernant la valence émotionnelle, la gamme entre récompense et aversion, est donc une capacité partagée à travers le règne animal. Elle doit être dynamique, car l’importance d’un stimulus peut dépendre du contexte ou évoluer au fil du temps, et est donc sujette à l’apprentissage. Un dysfonctionnement dans l’orientation du comportement par la valence peut produire une recherche de récompense insensible aux conséquences négatives, ou des comportements d’évitement …  Lire la suite