McGill University Thèses et mémoires par auteur commençant par T

Hydrogen oxidation by Azospirillum brasilense Sp7 was studied in N(,2)-fixing and NH(,4)('+)-grown batch cultures. The K(,m) for H(,2) of O(,2)-dependent H('3)H oxidation in whole cells was 9 uM. The rates of H('3)H and H(,2) oxidation were very similar, indicating that the initial H(,2) activation step in the overall H(,2) oxidation reaction was not rate-limiting and that H('3)H oxidation was a valid measure of H(,2)-oxidation activity. Hydrogen-oxidation activity was inhibited irreversibly by air. In N-free cultures the O(,2) optima for O(,2)-dependent H(,2) oxidation, ranging from 0.5-1.25% O(,2) depending on the phase of growth, were significantly higher than those of C(,2)H(,2) reduction, …  Lire la suite

La sclérose amyotrophique latérale (SLA) une maladie neurodégénérative caractérisée par une paralysie progressive causée par le dysfonctionnement et la perte des motoneurones dont l'origine est génétique ou sporadique. Une caractéristique commune aux différentes formes de la SLA est la rétraction des dendrites des motoneurones causant ainsi la déconnection des motoneurones spinaux d'avec leur connections centrales. Plusieurs gènes causant la maladie ont été identifiés, notamment le gène codant pour la DNA/RNA-binding protein fused in sarcoma/translated in liposarcoma (FUS/TLS) et responsable de SLA6. La localisation subcellulaire de FUS est principalement nucléaire et synaptique, cependant les mutants responsables de formes de SLA6 présentent …  Lire la suite

The following dissertation is a work on intellectual history focusing on the polemical work of the late seventeenth/ early eighteenth century missionary and convert ʻAlī Qulī Jadīd al-Islām (d. circa 1722). Throughout the work of this author, this study seeks to explore broader questions regarding the nature of interreligious polemics in the late Safavid period in Iran (1694-1722). As such, ʻAlī Qulī's opera is situated within the context of the intellectual debates of his time as well as within the larger history of the polemical genre known as "signs of prophethood" (dalā'il al-nubuwwah). Although most of this study focuses on …  Lire la suite

This study examined Filipino mothers' problem solving on issues related to child feeding, using a dyadic, peer-help approach. The participants were mothers of children under 6 years of age from the town of Camaligan, in the southern Philippines, where malnutrition among children is prevalent. Two studies were conducted: one using a controlled experimental session and the second using a multi-session nutrition education format. In the first study, mothers were paired with a mutual or unilateral friend to discuss a feeding problem to which they initially gave similar solutions and one to which they gave different solutions. Their post-discussion solutions were …  Lire la suite

Dans un roman où le Narrateur apparaît tour à tour comme héros, spectateur et commentateur désintéressé - où on peut selon les chapitres assister à l'éclosion d'une vocation, suivre l'évolution d'une société ou s'abandonner aux méandres de longues méditations philosophiques ou poétiques - nul n'est surpxis de se trouver à maint tournant face à face avec l'éternel protagoniste de toute destinée : la Mort. [...]  Lire la suite

The purpose of this thesis is to design a computer model which compares three sprinkler irrigation systems---portable pipe with volume gun, traveller with volume gun and towable/non-towable centre pivot---for potato production. The model user is required to enter a set of basic data: crop and field conditions, irrigation technical parameters and basic economic data, following which the model establishes the preliminary irrigation system and a comparative investment analysis. The model was applied and tested on a potato farm situated in Notre-Dame-de-la-Paix (southwestern Quebec). Based on a 14-year climatic analysis, supplemental irrigation for a normal rainfall growing period (368 mm) was …  Lire la suite

Afin de suivre le rythme croissant d'utilisateurs ainsi que les demandes de traitements résultants, les applications entreprise et de commerce électronique ont besoin d'innovations régulières dans leur conception et architecture. L'extensibilité ainsi que la disponibilité sont primordiales pour tout type d'affaires ayant intérêt à garder, voir même étendre, leur clientèle. L'architecture la plus populaire qui fournit en même temps l'extensibilité et la disponibilité est celle pour laquelle le serveur d'applications est répliqué. Une architecture au niveau de laquelle les serveurs d'applications partagent une seule base de données et chacun d'entre eux utilise des couches de cache afin de réduire la …  Lire la suite

There is a region of the upper atmosphere called the mesopause which currently excites much interest. This region lies approximately between the altitudes of 80 and 90 kilometers. Today, knowledge of conditions in this region is necessary to predict satellite orbit decay, but academic interest lies in the attempt to set up a consistent model atmosphere (e.g. Bates and Nicolet (1)). [...]  Lire la suite

An understanding of the effects of harvest on wild plant populations is essential for discerning the ecological impacts of past and present human uses of wild species, and for conserving species which are currently overexploited. This dissertation builds on theories and methods to describe and predict the impacts of harvesting non-timber forest products (NTFP) through an ethnoecological study of the terrestrial bromeliad Aechmea magdalenae. A. magdalenae is harvested from the rainforests of South-eastern Mexico where it has a long history of exploitation. The fiber extracted from its leaves is used to embroider leather articles in an artwork known as piteado. …  Lire la suite

Macallum, A. (Supervisors)  Lire la suite

Valid scientific claims are made based on replicable observations and, in this regard, the replication of published research is an important form of scientific validation. Although the broader scientific community is aware of this and replication has been deemed a cornerstone of the scientific method by the philosophy of science, little incentive exists to promote and facilitate the practice of replicating scientific studies as well as share replication results. This led to what has been called a “Reproducibility Crisis” in science and efforts are now underway to understand and remedy this crisis. The goal of this thesis is to bring …  Lire la suite

Les liposomes sont actuellement bien établis comme étant des modes de transport pour véhiculer plusieurs types de molécules bioactives, telles que l’anthracycline doxorubicine pour les thérapies anticancéreuses. Ils sont également utilisés dans l’industrie alimentaire, en particulier dans l’industrie des produits laitiers pour encapsuler des enzymes. Cependant, les procédés de fabrication conventionnels ont tendance à être longs, onéreux et encombrants. En outre, ils requièrent une multitude d’étapes additionnelles. Nous proposons ici une alternative simple: un dispositif microfluides à focalisation de flux double permettant la synthèse et le chargement rapide et contrôlé des liposomes. Contrairement aux méthodes traditionnelles d’évaporation de solvant, ce …  Lire la suite

In Canada, there is growing acceptance that tillage erosion is a serious form of soil degradation and a threat to the sustainability of agriculture across the country. To date, the potential for tillage erosion within potato (Solanum tuberosum L.) production systems has not been investigated. To address this issue, field experiments were conducted in northwestern New Brunswick to generate tillage translocation and erosivity values for primary, secondary and "tertiary" (i.e., field operations conducted during planting, hilling and harvesting) tillage implements commonly used for potato production. The potential for tillage erosion was equally high for the mouldboard plough, chisel plough and …  Lire la suite

The idea of expanding a function in terms of the solutions of a second-order differential equation was first presented in a paper by Sturm and Liouville in 1836. But they gave a proof which is now not accepted. The first satisfactory proofs were not constructed until early in the twentieth century. These early proofs by Hilbert and others were established only if the function together with its first and second derivatives is continuous. A presentation based on these early papers and attacking the problem by the sole use of the theory of differential equations is given by E.L. Ince in …  Lire la suite

This work is a study on software tools for the diagnosis of electrical equipment. It covers conventional and expert system methods, of which the latter are found to be more appropriate for the task. The interest in expert systems is directed towards those based on deep knowledge, meaning the structural and functional description of devices. A well-known approach for reasoning on complex structural knowledge consists of using qualitative models. The thesis explores the principal works in this domain and applies them to the diagnosis of electrical equipment in order to evaluate their limitations. Another approach is also considered, based on …  Lire la suite

Historically, the research scientist did not require a supporting organization for the pursuit of his scientific interests. There appears to have been a pattern followed by scientists until the early 18th century; many scientists were “gentlemen of leisure” and scientists by hobby. As well, the necessary equipment for scientific investigation in its rudimentary stages was inexpensive enough so that individuals could afford to purchase or construct their own. However the increasing complexity and cost of equipment and supplies used in scientific research has now made it practical and necessary for centralization and corporate ownership of research facilities.  Lire la suite

Nos approches et systèmes actuels d'action sur le changement climatique limitent notre capacité à promouvoir l'intersectionnalité, la communauté, la pensée axée sur la justice et les relations de collaboration entre les jeunes de couleur pour surmonter les obstacles auxquels ils sont confrontés et jouer un rôle actif dans la transformation des espaces climatiques communautaires. Ces systèmes et ces histoires d'oppression ont joué un rôle important dans la façon dont les communautés racialisées portent un fardeau disproportionné des catastrophes climatiques et affectent la façon dont les jeunes racialisés naviguent dans les espaces climatiques et agissent sur les défis environnementaux (White, 2011; …  Lire la suite

Metals have been produced, worked and used since prehistoric times. For thousands of years however, most of the knowledge relating to metals was acquired by chance and the experience gained was passed from man to man through the centuries. Thus, many important processes such as forging and annealing, were carried out for centuries without anyone realizing what structural changes were actually taking place. In fact no attempt to explain the changes that occur during annealing was made until 1881. In that year Kalisher observed that heating caused changes in the "molecular structure" of cold worked zinc.  Lire la suite

Lefsrud, Mark (Supervisor1)  Lire la suite

In acidic soils, aluminum (Al) and manganese (Mn) availability can be high and have a negative effect on plant growth and nutrition. Silicon (Si) has been studied for its ability to alleviate Al and Mn toxicity in agricultural crops. Despite its importance, only a few studies have examined Si uptake and interactions in trees. In this study, I first investigated Si, Al, Mn and Calcium (Ca) accumulation in leaves of sugar maple and American beech over a five-month period. Si uptake was found to be continuous for both species before reaching a plateau (Si concentration > 1%) at the end …  Lire la suite

Allison, Paul J. (Supervisor2)  Lire la suite

This thesis examines the religious policy of the caliph al-Mutawakkil ala Allah, the tenth Abbasid caliph, (232-247/847-861). The study focuses on the following headings: the main features of al-Mutawakkil's life and reign; his attitude towards 1) the Ahl al-Kitab, 2) the orthodox Muslims, 3) the Mu'tazila, 4) the Shi'a, and 5) the Sufis. It is suggested that although al-Mutawakkil's policy toward each of these groups was governed by his own strong orthodoxy, the policy was conditioned chiefly by political factors.  Lire la suite

This thesis presents an up-to-date survey of results concerning laws of large numbers for sequences and arrays of random variables. We begin with Kolmogorov's pioneering result, the strong law of large numbers, and preceed through to Hu et al.'s, and Gut's recent result for weakly dominated random variables, for which we provide a simpler proof. We insist in particular on the techniques of proof of Etemadi and Jamison et al. Furthermore, analogues to the Marcinkiewicz-Zygmund theorem are given. This thesis illustrates the trade-off between the existence of higher moments and non i.i.d sequences and arrays of random variables to obtain …  Lire la suite

The purpose of the present study is to recover from selected Hindu and Buddhist texts ideas and images of aging and illumine their historical, semantic and metaphysical dimensions. The results of this endeavor indicate that as cultural adaptive systems, both religion and gerontology share a common concern in seeking to provide aging with purpose and meaning. Further, the internal logic and semantics expressing this relationship in the texts examined are governed by the formal and literary modes of simile, metaphor and myth. The analysis of such age-sensitive concepts as jara (aging), asrama (stages of life), kala (time), parinama (change), karma …  Lire la suite

In 1917 Soddy in discussing his ideas about atomic nuclei conceived the possibility of nuclei having the same charge and mass but being different in their radioactive behaviour. Hahn first discovered this phenomenon of nuclear isomerism in 1921. He found two beta activities of half-lives 1.15 minutes and 6.7 hours in the decay of thorium extracted from natural uranium, both of which activities reverted to uranium. We now know the decay chain to be as follows.  Lire la suite

This study examines micro-social processes in a comparatively underdeveloped sector of our economy, that of small-unit rental housing. Its specific focus is on owner-tenant relations in a changing neighbourhood. An attempt is made to identify and describe social forces at work in these relations and to trace their implications for neighbourhood decline.  Lire la suite

An understanding of the mechanisms operating in nuclear reactions produced by high energy nucleons is of considerable interest. The experimental investigation of these processes may be grouped into two categories: l. Measurements are made of the excitation function for the production of a certain isotope. 2. The energy and angular distributions of the emitted partiales are studied. [...]  Lire la suite

Most bullying and peer victimization occurs in schools (Kasen, Berenson, Cohen, & Johnson, 2004), making teachers essential to intervention efforts (Salmivalli, Kaukiainen, Voeten, & Sinisammal, 2004). However, school staffs' understanding of bullying may influence whether they actually perceive incidents as bullying and whether they intervene appropriately. Though the damaging effects of peer victimization are widely recognized (see Hawker & Boulton, 2000 for a review), a consensus on a single definition of bullying has proven difficult to achieve. As such, the current study investigated perceptions and understandings of bullying and peer victimization in a unique sample of 100 school personnel from …  Lire la suite

Les troubles anxieux de l'enfance se manifestent en moyenne avant l'âge de 13 ans (Solmi et al., 2022), les difficultés de régulation émotionnelle étant un facteur de risque important dans le développement et le maintien de l'anxiété infantile (Malhi et al., 2017). La thérapie cognitivo-comportementale (TCC) est une approche efficace pour le traitement de l'anxiété et de la dysrégulation émotionnelle chez les enfants et les adolescents (Hugh-Jones et al., 2020 ; Suveg et al., 2009 ; Vallis et al., 2020), et les écoles constituent un cadre pratique et rentable pour fournir des efforts de prévention et d'intervention ciblant ces symptômes …  Lire la suite

There is a need for effective and environmentally sensitive methods of controlling vertebrate pest problems in agriculture and urban environment. Nonlethal natural repellents may meet this need where more traditional methods of control, such as scaring, shooting, and trapping, are either ineffectual or unacceptable. Neem (Azadirachta indica A Juss) extracts: oil, seed and leaf powder and chemicals from cockroach (Blaberus giganteus L.) were tested for their repellent properties. In addition defensive volatiles from B. giganteus were tested in an arena based on choice by smell (cheese or insect volatiles). This arena test used laboratory rats (Rattus norvegicus Berk.); females were …  Lire la suite

We perform a three-dimensional linear stability analysis of a laminar flow in a channel delimited by rigid, homogeneous, isotropic, porous blocks. We consider porous materials in which the permeability is small and the inertial effects can be neglected. We solve the coupled linear stability problem, arising from the adjacent channel and porous flows, using a spectral collocation technique. We consider symmetric flows in channels with two identical porous walls and skewed flows in channels with only one porous wall. In both cases, permeability significantly affects the Orr-Sommerfeld spectrum; however, the homogeneous Squire modes remain damped. In channels with two porous …  Lire la suite

We investigate the effects of wall permeability on the linear stability of two classical wall-bounded shear flows. In the first part of this thesis, we consider pressure driven, incompressible, fully developed, laminar flow in a channel delimited by rigid, homogeneous, isotropic, porous layers. We consider porous materials of small permeability in which the flow velocity is small and for which the inertial effects can be neglected. We solve the fully coupled, temporal, linear stability problem arising from the adjacent flows in the channel and porous regions. We perform a parametric study in which we vary the permeability, porosity, and height …  Lire la suite

Using the social sciences, demography and cultural history, this thesis examines the Irish Protestants of Montreal between 1834 and 1860. Its main focus is the communal identity that had both an Irish and British basis. Using national and political societies such as the Saint Patrick Society, Irish Protestant Benevolent Society as well as the Orange Order, the thesis demonstrates how the identity of the Irish Protestant was forged from relationships with other cultural groups of the city. Central to the development of a Protestant Irish communal identity separate from that of Irish Catholics was the increasing presence of Ultramontanism in …  Lire la suite

The ADP-induced aggregation of rabbit platelets was used to provide supportive evidence to the fact that the biologically active component of the eosinophil-derived inhibitor (EDI) is a prostaglandin (PG). By inhibiting the ADP-induced aggregation of platelets, the EDI behaved like PGE1. Efforts were made to quantitatively estimate the amounts of PGE1 that are present within different EDI samples. After establishing that a particular EDI extract possessed inhibitory activity in, the histamine , release assay (HRA), these same extracts were then compared for their activity in bath the platelet aggregation (PAA) and rat stomach strip assay (RSSA) to that of standard …  Lire la suite

In education, the term "development" is used in many contexts. For example, we refer to the "development of student learning," the "development of epistemic beliefs," and the "development of expertise." The term "development" is also central to our identity and work as educational developers. The frequent use of this term suggests a commonly agreed-upon understanding; however, closer analysis reveals that the definition of this term remains vague. Drawing on literature in the areas of epistemic beliefs and threshold concepts, this dissertation intends to elucidate the notion of development by exploring what development is and how it happens. Insights from this …  Lire la suite

N/A  Lire la suite

This research seeks to pinpoint the telencephalic structures most closely correlated with feeding flexibility, which is operationalised as feeding innovation rate per taxon. By calculating a weighted average per taxon of 1030 feeding innovations collated from five zones of the world (western Europe, North America, Australia, New Zealand and India), the study shows that relative size of the hyperstriatum ventrale and, to a lesser extent, the neostriatum , best predicts weighted innovation rate; these two structures are thought to be functionally equivalent to the mammalian neocortex. The worst telencephalic predictors of innovation rate are two structures respectively thought to be …  Lire la suite

Background: Sexual assault evidence kits (SAEKs) are used to gather forensic evidence from survivors following sexual assault. Forensic evidence collection also coincides with comprehensive post-assault care and referrals to follow-up services. One third of Canadian women have experienced sexual assault, however many hospitals lack staff trained in SAEKs and sexual assault care. Most of these deficits fall in rural areas, forcing survivors to travel long distances to receive care; Northern communities are known to especially lack access to comprehensive sexual assault care and SAEKs. This lack of resources has implications for both rural and urban Northern communities, and can also …  Lire la suite

A methodology is developed for the interpretation of complex Early Iroquoian villages based upon the analysis of site formation processes. This interpretive method is applied to a study of the Calvert site, a twelfth to thirteenth century Iroquoian village located in southwestern Ontario. Four phases in the occupational history of the village are reconstructed and changes in its economic and socio-political organization are examined through a comparative analysis of data from each construction phase. The systematic rebuilding and long-term use of the village indicate significant planning on the part of the Calvert people and suggest that at least some Early …  Lire la suite

Les éléments à champ électrostatique élevé (HFSE, high field strength elements) sont considérés comme étant immobiles dans de nombreux environnements géochimiques, dans lesquels les fluides hydrothermaux de température élevée jouent un rôle important dans leur transport. Parmi les métaux considérés dans cette thèse, le niobium est souvent utilisé comme élément de référence, par rapport auquel la mobilité des autres éléments est comparée; le tantale est également considéré comme étant difficile à transporter; et l'uranium, connu pour être particulièrement mobile dans les environnements oxydants, est considéré comme étant immobile dans les systèmes réduits. À l'aide d'observations de terrain et d'études expérimentales, …  Lire la suite

A three phase fluidized bed was constructed for microencapsulation. Smooth, spherical, small diameter nylon microcapsules and alginate microspheres were formed in the fluidized bed by the method of interfacial polymerization and emulsification/internal gelation respectively. The mean diameter of the microspheres ranged from 100 to 800 $ mu$m was controlled by varying emulsifier concentration, gas flowrate, emulsification time, dispersed phase viscosity, column height to diameter ratio and the dispersed phase concentration. Double stranded calf thymus DNA was encapsulated within alginate microspheres by the fluidization technique. A method of quantifying DNA recovery in the microspheres without requiring prior separation of the DNA …  Lire la suite

The roles of cyclic AMP and protein kinase A in regulating high-affinity choline uptake under resting as well as depolarizing conditions were investigated. The cyclic AMP analogue 8-bromo-cyclic AMP (500muM), or a combination of the adenylyl cylase activator forskolin (20 muM) and the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (10 muM) increased choline uptake in rat hippocampal synaptosomes. Of the four protein kinase A inhibitors studied, H-89 (60--200nM) and KT5720 (0.49--1.12 muM) suppress 8-bromo-cyclic AMP enhancement of choline uptake, whereas H-8 (13muM) and Rp-8-bromo-cyclic AMP (675 muM) did not. H-89 but not KT5720 was found to dose dependently suppress high-K+ enhancement of choline …  Lire la suite

The development of computer algorithms for music instrument identification and parameter extraction in digital audio signals is an active research field. A musician can listen to music and instantly identify different instruments and the timbres produced by various playing techniques. Creating software to allow computers to do the same is much more challenging. This thesis will use digital signal processing and machine learning techniques to differentiate snare drum timbres produced by different stroke positions and stroke techniques.  Lire la suite

De nombreuses théories suggèrent que le cortex est impliqué dans l'apprentissage prédictif. Parmi celles-ci, plusieurs avancent que le couplage somato-dendritique pourrait être essentiel à la prédiction hiérarchique qui sous-tend cet apprentissage. Cependant, les mécanismes proposés divergent quant à savoir si ce couplage est induit par la concordance ou la discordance avec les attentes. Dans cette étude, nous examinons si la concordance ou la discordance avec les attentes entraîne une augmentation du couplage somato-dendritique en observant directement l'activité de ce couplage dans le cortex visuel lors de la présentation d'entrées sensorielles inattendues. Plus précisément, nous utilisons un mésoscope multiplan pour observer …  Lire la suite