McGill University Thèses et mémoires par auteur commençant par A

Les trous noirs primordiaux sont un type de trous noirs qui pourraient s'être formés par des fluctuations de densité durant les premiers instants de l'univers. Il est aussi probable que les trous noirs, de façon général, s'évaporent continuellement. Si des trous noirs primordiaux avec une masse initiale de 10^14g (ou de 10^−20 fois la masse du Soleil) se sont formés, leur évaporation se terminerait à notre époque, dans une explosion de rayons gamma à trè hautes énergies. Des télescopes à rayonnement Cherenkov, tel que ceux utilisés par l'expérience VERITAS, peuvent chercher ces explosions de trous noirs dans leurs données, dans …  Read more

This thesis describes preliminary research on the application of Markov Decision Processes (MDPs) to the optimisation of mine scheduling in an uncertain environment. The MDP framework is a novel approach to scheduling in a mining operation and option valuation. The task of scheduling in mining operations is dependent on the availability of models that permit the representation of some of the key stochastic properties of the environment, such as grade and price uncertainty. The tools used to model these processes are respectively sequential Gaussian simulation and Geometric Brownian motion. Three cases of increasing size are used to illustrate the results …  Read more

While learning about cues that predict danger is fundamental to survival, so too is learning about when these same cues no longer present a threat. In Pavlovian fear conditioning, pairing a previously neutral stimulus (tone) with an aversive outcome (shock) results in a conditioned fear response. The ability of a stimulus to elicit fear is gradually reduced if that stimulus is no longer accompanied by an aversive consequence. The diminishing fear response that occurs when, for example, the tone is repeatedly presented without the shock, is known as extinction. The experiments presented in this dissertation characterize temporal factors involved in …  Read more

"The goal of this thesis was to develop a framework that could integrate and analyse industry-wide information for the support of on-farm decision-making in dairy-cattle breeding. Specific objectives included (i) describing a dairy breeding information system (DBIS); (ii) examining how the Internet could be exploited to improve the DBIS and its functioning; (iii) describing a process for implementing a unified data model to facilitate integrated user access to information in the DBIS; and (iv) developing software to support decision-making by facilitating access to a unified data model when implemented as a database management software. The first objective was achieved by …  Read more

On a étudié l'effet de deux bloqueurs calciques de type dihydropyridine sur le metabolisme cerebral du glucose (LCGU), le débit sanguin (LCBF) et leur ratio (LCBF/LCGU), en presence d'une lésion cryogenique chez le rat. […]  Read more

Fluctuations of sea level in the recent past are well documented in the landscapes of northern Canada by the existence of raised strandlines with marine shells and emerged off-shore deposits. However details of these fluctuations in many areas remain to be resolved and their relationship to glaciation and deglaciation needs to be determined. [...]  Read more

The scope of this work consists mainly in the continuation of the work already begun by P.J. Harris entitled "The Analysis of Axially Symmetric Spherical Shells by Means of Finite Differences". The purpose is to analyse the influence of various boundary conditions at the apex of the shell, particularly that of a lantern ring at the top, but otherwise under the same restrictions as the previous work. [...]  Read more

Weinstock, Daniel (Internal/Supervisor)  Read more

The Arctic is widely acknowledged as a global hotspot of climate change impacts. The implications of these changes are particularly pronounced for the Indigenous populations living in arctic regions, whose close association with and dependence on the land, sea, ice, and natural resources increases their sensitivity to climate-related risks. The past decade has seen the rapid expansion of research assessing these risks, which has increased our understanding of how climate change interacts with non-climatic drivers of vulnerability and resilience to affect human society. However, our understanding of the dynamic nature of vulnerability and its determinants over time remains incomplete: while …  Read more

To interpret the permeability phenomena which are exhibited by cellulose, a knowledge of its structure and certain physical properties is essential. Although the present study is concerned with cellophane, which is a regenerated form of cellulose, it is preferable first to consider these aspects in native cellulose, and subsequently to describe the changes which occur as a result of regeneration.  Read more

This thesis studies intersection theory on projective surfaces with isolated singularities. We review the classical intersection theory on a nonsingular surface, proceed to an overview of types of singularity that may arise, and then discuss the intersection theory of Snapper-Kleiman, that of Reeve-Tyrrell, and a modification of the latter that we propose. The intersection theory of Snapper-Kleiman applies to varieties of any dimension but is restricted to locally principal divisors; that of Reeve-Tyrrell applies to arbitrary divisors but is restricted to surfaces. Our modification has the same domain of application as the theory of Reeve-Tyrrell but simplifies computations: it allows …  Read more

Chez l’être humain, la majorité des cancers proviennent de cellules épithéliales qui subissent une transformation maligne. L’activité ainsi que la présence élevée de Protéine Kinase C atypique (aPKC) est retrouvée parmi beaucoup de cancers dérivés de cellules cpithéliales. Plusieurs recherches ont démontré un rôle oncogène de l’aPKC. Cependant, il n’y a pas de recherches qui indiquent si un gain-de-fonction de l’aPKC dans un contexte épithélial normal est suffisant pour provoquer une transformation maligne.En sur-exprimant une forme active de aPKC (aPKC-ca) dans une cellule épithéliale avec polarisation normale, nous avons montré qu’un gain de fonction est suffisant pour pertuber la polarité …  Read more

Dans cette thèse, je décris la découverte et l'investigation d'un objet transitionel, PSR J1023+0038 (J1023 subséquemment). Cet objet à ce moment appert être un pulsar radio à période milliseconde (MSP) mais apparemment avaît un disque d'accrétion en 2001. Ce fait identifie J1023 comme étant en transision à une phase mal comprise dans la séquence evolutionnaire des pulsars, à la fin d'une phase binaire aux rayons X à faible masse (LMXB) et au début d'une phase MSP. Je discute les preuves pour cette interprétation et comment cette interprétation s'accorde avec nos modèles d'evolution LMXB/MSP. Je décris aussi les observations en rayons …  Read more

Cette thèse évalue comment la phénologie reproductive influence la collecte de cône d'épinette blanche par l'écureuil roux, de la perspective de l'arbre et de l'écureuil. Chez l'épinette blanche, nous avons évalué le degré de synchronie reproductive intra-annuelle de chaque arbre relatif à la population et le nombre de cône (graines) qui échappe à la collecte des écureuils roux. Pour deux années avec des productions de cône très différentes au niveau populationnel, les épinettes blanches davantage synchronisées intra-annuellement dans leur phénologie reproductive ont davantage de graines qui échappent aux écureuils, menant vers une sélection directionnelle positive sur ce trait lors d'une …  Read more

This study examined the status of 50 retired profes­sional social workers, 43 female and 7 male. The sample was identified from lists provided by the Corporation of Profes­sional Social Workers, English Chapter, Montreal, and the McGill University Alumni Society. The retirees were surveyed through the use of a devised questionnaire designed to obtain pertinent data concerning level of education, health, housing, income, activities, satisfaction with life in general, the retirement experience, and orientation to the social work profession. Findings revealed that this group of retired professional social workers have a superior educational back­ground, they are generally in good health and …  Read more

DeVoe, Dr. I.W.  Read more

Pulsars are the rotating compact remnants of exploded massive stars. The region surrounding the neutron star, known as the magnetosphere, has properties which are determined by the magnetic ield of the star. In this thesis, I present several observational results involving rotation-powered radio pulsars and magnetars which indicate that pulsar magnetospheres have a more complex structure than a simple dipole, and that the magnetosphere can have a strong efect on all the observed properties of neutron stars. One way to probe the pulsar magnetosphere is through the measurement of braking indices. A braking index quantifies the dependence of the torque …  Read more

Magnetars are neutron stars showing dramatic X-ray and soft γ-ray outbursting behaviour that is thought to be powered by their intense internal magnetic fields. Like conventional neutron stars in the form of radio pulsars, magnetars show sudden changes in their rotation rate, called "glitches," during which angular momentum is believed to be transferred between the solid outer crust and the superfluid component of the inner crust. Hitherto, the several hundred observed glitches in radio pulsars and magnetars have involved a sudden spin-up of the star, due presumably to the interior superfluid rotating faster than the crust. In this thesis, we …  Read more

The solubility of gold and copper chloride in liquid-undersaturated, HCl-bearing water vapour was investigated experimentally at elevated temperatures and pressures. Experimental results show that the solubility of gold and copper is significant, increasing at higher fHCl and fH2O for gold, and at higher fH2O for copper. These increases are attributed to the formation of hydrated gas species, with a metal:chlorine ratio of 1. Hydration numbers vary from 5 at 300°C to 3 at 360°C for gold, and from 7.6 at 280°C, to 6.0 at 300°C, and 6.1 at 320°C for copper; the results reflect the presence of trimer [Cu3Cl3•(H2O)n] or …  Read more

The study of the patristic quotations has long been appreciated as an important source in New Testament Textual Criticism. The unique value of the church Fathers lies in the fact that we know when and where a father wrote. Their citations of Scripture, both in their expositional and polemical writings, often help the researcher identify the relative antiquity and geographical location of variant readings. The justification for studying the New Testament text of Didymus the Blind can be easily expressed. Born c. 313 and later head of the catechetical school in Alexandria, Didymus was endowed with a prodigious memory and …  Read more

Background: In recent years, Canadian universities have been striving to improve engagement with Indigenous Peoples, knowledges and perspectives. Despite these efforts, and in the absence of national guidance, little is known about what changes are taking place in physiotherapy curricula, nor what processes are undertaken to develop and implement these changes. Objective: The purpose of this study was to explore how Canadian physiotherapy curricula are changing in relation to Indigenous Peoples and their communities.Methods: This study used a cross-sectional design informed by a theoretical framework of transformative learning. Canadian physiotherapy program faculty participated in a questionnaire-based interview from February to …  Read more

Higher education is experiencing a changing context. Strong leadership is demanded to overcome these challenging times. While management literature offers the transactional-transformational leadership model, the higher education literature argues that applying a managerial leadership model to the academic context ignores the principles of academe. This study examines the relevance of such a model within the academic context. More specifically, the study focuses on transactional-transformational leadership styles and the extent to which chairs' self and faculty members' perceptions of chairs' leadership converge. The study also examines the perceptions of the influence of leadership style on departmental outcomes, extra effort, effectiveness, and …  Read more

As a consequence of the American deregulation policy, combined with the effects of the economic crisis and that of the realization of the "unique market", the European airline industry is undergoing a large movement of re-structuralization. The European Commission admitted the inevitable character of this trend towards concentrations among transporters but wished to control the issue, to prevent any infringement to the principles of competition as stated in the EEC Treaty. Initially elaborated by a consequent jurisprudence of the European Communities Court of Justice, this control led to the adoption in 1989, of a specific regulation on concentrations. Considered as …  Read more

L’intelligence artificielle (IA) est aujourd’hui profondément intégrée dans la vie contemporaine, avec des applications qui se multiplient dans un large éventail de domaines. Au cœur de l’IA se trouvent les réseaux de neurones, qui ont considérablement renforcé les capacités des systèmes intelligents, notamment dans les domaines de la vision par ordinateur et du traitement du langage naturel. Cependant, à mesure que les réseaux de neurones gagnent en taille et en complexité computationnelle, les dispositifs intelligents chargés de leur exécution doivent faire face à des exigences croissantes en matière de ressources de calcul et d’énergie pour garantir des performances efficaces et …  Read more

Artificial Intelligence (AI) is a technology that is rapidly changing our world and driving a new industrial revolution. We envision a world with intelligent devices that are able to perceive, reason and take intuitive actions. The new vision of intelligent devices requires inexpensive, low-energy and fast hardware platforms. However, state-of-the-art AI algorithms are both computationally and memory intensive, making them difficult to deploy on embedded devices with a stringent power and timing budget. In this dissertation, we focus on efficient processing of AI algorithms to address the aforementioned issues. On the software side, we modify state-of-the-art AI algorithms by reducing …  Read more

L'industrie minière est connue pour être risquée. Les prix des produits de base fluctuent considérablement et tombent souvent en dessous des coûts de production. Les estimations des ressources et des réserves sont faites en utilisant des données de teneur clairsemées et entraînent inévitablement des erreurs. En plus du prix et de la teneur, il existe un grand nombre de paramètres incertains impliqués dans les estimations des ressources et des réserves, notamment: les coûts d'exploitation; les taux d'imposition; les pourcentages de remise; les grades de coupure; les caractéristiques de l'eau, du sol et de l'air sur le site de la mine; …  Read more

Cette thèse propose un cadre novateur reliant la philosophie acousmatique du son de Pierre Schaeffer aux concepts modernes d’apprentissage automatique. Elle questionne la tendance dominante en synthèse audio neuronale, qui restreint souvent l’approche neuronale à la modélisation de formes musicales préexistantes, et plaide pour une réinterprétation qui englobe le concept Schaefferien du son lui-même. En établissant des parallèles entre la musique acousmatique et la synthèse audio neuronale—toutes deux opérant dans des environnements de type ‘boîte noire’ qui mettent en avant les propriétés invariantes du son—notre approche formalise ces connexions à travers la théorie de la représentation des groupes en soutenant …  Read more

The purpose of this study was to determine the timing and extent of gains in strength, mobility, balance and functional status that follow a high-intensity strengthening program offered to two groups of institutionalized elderly subjects. Thirty two subjects were randomly selected and classified as a person with a HIGH or LOW mobility based on the timed "Up and Go" (TUG) score (<20 sec or ≥20 sec respectively). The hypothesis was that the exercise regimen would have a greater impact on the LOW mobility group as compared to the HIGH mobility group. Dynamic strength, mobility, balance and functional level were evaluated …  Read more

Our laboratory identified pyridoxal isonicotinoyl hydrazone (PIH) as an orally effective Fe chelator (BBA 586:278 1979). More recent in vitro and in vivo studies with PIH analogs have demonstrated that halogenated pyridoxal benzoyl hydrazones are more effective iron chelators than PIH. In this study, 33 analogues were synthesized and assessed. The compounds were derived from 3 parent aldehydes: pyridoxal (100 series), salicylaldehyde (200 series) and 2-hydroxy-1-naphthylaldehyde (300 series) in combination with the ortho-, meta -, and para-isomers of halogenated benzhydrazides: chloro (08), fluoro (09), bromo (10), and iodo (10.1). Fe chelators were evaluated on the basis of their ability to …  Read more

A significant amount of work has been directed toward the improvement of mine backfill during the past decades. Paste backfill was recently introduced as a superior support system for underground hard rock mining operations. The aim of this study is to examine the applicability of paste backfill to full scale underground operations. The Tailspinner system was developed to produce paste backfill. This system dewaters the full stream tailing material from approximately 55% to 24% water content. These densified tailings are mixed with cement prior to placement in a stope. The utilization of paste backfill possesses several economical and mechanical advantages. …  Read more

The interface between copyright law and competition law has always been a topic of debate in legal and economic circles. Since the last decade however, new economy markets pose new challenges to this interface. Network effects, interconnectivity, rapid innovation, and excludability are characteristics of new economy markets. Particularly network effects can, in connection with copyright protection, increase market power and provoke competition authorities to monitor the exercise of copyrights. This thesis contains an analysis of the background and underlying principles of Canadian copyright law and competition law. It gives an overview over their interface in the legislation and the impact …  Read more

Tumbling mills, which consume around 6% of world's electric power, though inefficient (use 1% of the supplied energy) have been used in mineral processing industry for over a century. Harsh internal mill environments have prevented the access to in-mill dynamics. This situation has led researchers to develop models based on the Discrete Element Method (DEM) to predict internal mill dynamics. But before DEM models can be used in the mineral processing industry, their rigorous validation is essential. In this thesis, we have carried out real time analysis of the DEM model to enable online availability of the mill parameters for …  Read more

Nicolau, Belinda Farias (Internal/Supervisor)  Read more

Nicolau, Belinda Farias (Supervisor1)  Read more

This Master's thesis aims to answer two questions: (1) Why do states sign international investment agreements (IIA)?; (2) What determines the substantive strength of these agreements? I use an event history analysis and an ordered logit model, respectively, to answer these questions. I find partial support for the hypothesis according to which the interests of capital-exporting states determine the pattern of IIA diffusion. While the results of my second test are somewhat inconclusive, they allow me to draw a number of interesting lessons for future research.  Read more

La planification minière à court terme des opérations souterraines est considérée complexe et à la fois cruciale, non seulement pour la réussite des opérations, mais aussi pour la réalisation des objectifs fixés par la planification à moyen et long terme. De plus, les opérations souterraines sont également connues pour avoir un nombre important de décisions indépendantes concernant les ressources disponibles, les tâches particulières à accomplir et les aspects techniques des tunnels. Pour avoir une productivité élevée, il est donc nécessaire d'utiliser un outil d’aide à la décision pour établir des plans de production à court terme. Par ailleurs, l'intégration de …  Read more

L’intérêt pour la bioélectronique a augmenté récemment, avec une utilisation accrue de dispositifs portables qui collectent différents bio-signaux. Ces interfaces seront en contact direct avec des tissus biologiques et doivent être biocompatibles. La plupart de ces dispositifs sont fabriqués en incorporant une charge conductrice dans des échafaudages biologiques, le principal défi étant d'équilibrer des conductivités élevées sans affecter leurs propriétés mécaniques.Un échafaudage potentiel qui peut être utilisé est celui des fibres curli, des protéines amyloïdes qui font partie de la matrice extracellulaire dans les biofilms produits par les entérobactéries. Les fibres curli peuvent adhérer à de multiples surfaces, ce qui …  Read more

A Control Volume Finite Difference (CVFD) code which finds the heat transfer coefficients resulting in a calculated thermal field that matches the thermal field obtained in experiments, was developed. The code is capable of solving unsteady conduction. and convection-diffusion problems in two or three dimensions using cylindrical coordinates. The complex problem of the workpiece cooling, was decomposed into smaller sub-problems corresponding to the different cooling zones. For each sub-problem an inverse-problem approach was applied using data from cooling experiments as a reference. As the result, the heat transfer coefficients were determined for a workpiece cooling in air, including the effect …  Read more

This thesis reports work not only on the numerics behind, but also the implementation of real-time redundancy-resolution schemes on a real robot. Furthermore, the robot that was chosen as the experimental platform is, isotropic. Redundant robots have more degrees of freedom than needed to perform a class of tasks. A new performance index is proposed in the thesis, that is quadratic in the joint variables and its weighting function has units of frequency. It is shown how this performance index can produce cyclic trajectories in a simple manner, thereby eliminating the undesired drift of the joint angles upon tracking a …  Read more

Data matching is the automated process permitting the comparison of significant amounts of personal data from two or more different databanks in order to produce new information. Its use by governments implicates many rights and freedoms, including the protection against unreasonable search and seizure under section 8 of the Canadian Charter. In the author's opinion, a governmental data matching program will probably constitute a search or seizure under section 8 when a positive answer is given to two questions. First, is there a use or transfer of information which implicates constitutionally protected information? Generally, section 8 will only protect biographical …  Read more

Le volet critique de ce mémoire se propose d’observer les enjeux découlant de la mise en livre du blogue d’Éric Chevillard, L’autofictif, dont la nécessité qu’elle implique de lire et d’interpréter le produit d’un support par l’entremise d’un autre. S’appuyant sur la notion du livre comme totalité matérielle et signifiante, et celle du blogue en tant que médium de la fluidité, l’analyse démontre que les volumes publiés de L’autofictif activent un certain nombre d’effets génériques et médiatiques significatifs d’une pratique d’écriture propre à la forme blogue, et que ces effets, présents dans les livres, sont susceptibles alors d’en bousculer la …  Read more

Ward, Brian (Supervisor)  Read more