McGill University Thèses et mémoires par auteur commençant par É

Thirsty rats, permitted to drink a novel tasting solution (decaffeinated coffee) followed by 15 min of intracranial self-stimulation (ICSS) subsequently demonstrate a preference for that novel solution. In control groups, rats presented with either self-stimulation alone or the novel solution alone, did not exhibit any such preferences. Additional experiments demonstrated that the resistance to extinction of these preferences reliably increased with the number of taste/ICSS pairings. It was also determined that preference size varied as a function of the intensity (i.e. reward strength) of the stimulation and not merely the number of stimulations. Furthermore, while conventional rate measures of brain-stimulation …  Lire la suite

Lane, Gillian (Internal/Supervisor)  Lire la suite

By submitting 'this thesis to the Faculty of Graduate Studies and Research, the writer thereof makes no pretension or claim to a 'new' contribution to the study of Feelings and Emotions. The forelying work is merely a preliminary and prerequisite inquiry into the subject, being indispensible 'to a more thorough and more definite (and, let us hope, -- a more original) study of the emotional life of the preschool child that the writer of the following began last fall and hopes to contiue at the Nursery School of the McGill University. After serious and logical thought one must eventually come …  Lire la suite

Given a polygonal curve $P = lbrack p sb1,p sb2 ... p sb{n} rbrack$, the polygonal approximation problem considered in this thesis calls for determining a new curve $P sp prime = lbrack p sbsp{1}{ prime}, p sbsp{2}{ prime}, ..., p sbsp{m}{ prime} rbrack$ such that (i) m is significantly smaller than n, (ii) the vertices of $P sp prime$ are a subset of the vertices of P and (iii) any line segment $ lbrack p sbsp{A}{ prime}, p sbsp{A+1}{ prime} rbrack$ of $P sp prime$ that substitutes a chain $ lbrack p sb B, ...,p sb C rbrack$ in …  Lire la suite

It is well known that in mammals bilateral nephrectomy results in striking electrolyte changes, hypertension, changes in Gibbs-Donnan equilibria and cell swelling in many organs - consistent with permeability alterations - and progressive irreversible myocardial lesions. To determine the relationships between these events, two groups of bilaterally nephrectomized rats were studied from several points of view. One group was given tap water, and the other 0.5% NaCl to drink after nephrectomy to enhance the changes produced by electrolyte derangements and to accelerate hypertension. In a third group, special permeability alterations were studied in rats treated similarly to group l (tap …  Lire la suite

Many audio signals of historical interest are stored on degraded analog media, such as phonograph records. Degradation is often associated with audible disturbances that can be annoying for listeners. Audio restoration uses digital signal processing technology to reduce artifacts associated with noise in audio signals. Click restoration, in particular, addresses corruption by impulsive noises. This project developed click restoration software using a well-known autoregressive model-based method for the detection and suppression of clicks. The restoration results were subjectively assessed by expert listeners who rated the audio quality associated with phonograph recordings restored by the autoregressive method and compared to a …  Lire la suite

Latimer, Eric A (Supervisor1)  Lire la suite

Justification et Objectifs: La consommation chronique de cocaïne est associée à des déficiences dans l'apprentissage par renforcement, avec une diminution spécifique de la sensibilité aux conséquences positives et négatives. Nous avons cherché à comparer les stratégies d'apprentissage des souris mâles et femelles tout au long de l'acquisition d'une tâche de prise de décision, puis à caractériser l'émergence de déficiences induites par la cocaïne dans l'apprentissage par renforcement positif et négatif chez les souris mâles et femelles.Méthodes : Des souris mâles et femelles ont été entraînées à acquérir une tâche déterministe d'apprentissage par inversion (DRL). L'impact des injections quotidiennes de cocaïne …  Lire la suite

An Insufficiency est une œuvre en trois mouvements écrite pour violon, violoncelle et piano. Les mouvements sont appelés « Love », « Hate », et « Not Otherwise Specified ». Chaque mouvement adapte librement une forme classique (sonate-allegro, ternaire et rondo), utilise des gammes synthétiques (presque diatoniques) avec des centres tonals bien définis, et des rythmes asymétriques avec des pulsations claires. L'orchestration des mouvements extérieurs privilégie une écriture fine et transparente au piano pour créer une texture équilibrée entre les trois instruments, tandis que le mouvement central repose sur des accords denses pour créer une texture plus épaisse et opaque …  Lire la suite

Salmonella is a ubiquitous Gram-negative bacterium that causes both food and waterborne illnesses. Infection outcome can vary between individuals within the population and result in a spectrum of illnesses: localized gastroenteritis, systemic disease of typhoid fever, or chronic disease. The most severe outcome following Salmonella infection is that of enteric fever where Salmonella disseminates and replicates in peripheral tissues. In untreated and susceptible individuals, systemic infection can trigger sepsis and potentially lead to tissue damage, organ failure and even death. Salmonella Typhimurium infection outcome in mice resembles several of the clinical manifestations and pathologies observed in humans with typhoid fever. …  Lire la suite

The net result of the Escherichia coli signal transduction pathway is the modulation of the direction of flagellar rotation, which in turn controls the swimming behaviour of the cell. We investigated the effect of different factors on the rates of CheY phosphorylation and dephosphorylation, utilizing purified proteins and working at appropriate time scales. Furthermore, we defined the kinetics for phospho-transfer from CheA to CheY and for CheY dephosphorylation under a standard set of conditions. Having established these assays we were now in a position to determine how other components of the chemotaxis system, such as receptors, CheW, and CheZ influence …  Lire la suite

Étude détaillée de l'œuvre de l'auteur "Motionless Move" qui montre l'application de quelques techniques de composition tirées de la musique de gamelan javanais, notamment: une mélodie-cantus firmus a caractère modal, une polyphonie hétérophonie par strates bien différenciées ainsi qu'une structure colotomique. L'œuvre écrite pour un ensemble de quatorze musiciens a été ensuite adaptée pour orchestre. Aussi, on étudie quelques aspects de cette orchestration.  Lire la suite

Yargeau, Viviane (Internal/Cosupervisor2)  Lire la suite

Previous experimenters have nearly all rendered their results valueless for purposes of independent comparison by employing vulcanised or sheet rubber of unspecified, if not unknown, history and composition, such as "black rubber tubing", etc., and in most cases have assumed the swelling to reach a maximum within twenty-four hours. This is an obvious fallacy in the light of the following results. [...]  Lire la suite

Much has been said concerning the value of welded fabrication in structural steel design. In fact, so rapid has been the growth of this method of contruction, that the investigation of its possibilities has been a subject of much research in recent years. Usually when a new method is in its infancy, its limitation and its adaptability are deduced, first, by "trial and error". Tests are carried out to ascertain its properties under certain required conditions, and if the tests prove satisfactory the method is adopted. In due course, by means of mathematical deduction and laboratory research, general laws are …  Lire la suite

La sécheresse peut avoir un impact désastreux sur l'environnement et la société. Une sécheresse importante peut provoquer des conséquences catastrophiques sur différentes activités socioéconomiques comme l'agriculture et l'agroalimentaire, la production hydroélectrique et la gestion des volumes d'eau. Une telle sécheresse a sévit entre 2001 et 2002 dans les prairies canadiennes où des pertes sans précédent ont affectées l'économie à la grandeur du pays. La présente étude caractérise les précipitations à petite échelle à trois endroits : Calgary, Edmonton et Saskatoon. Climatologiquement, les journées présentant de faible précipitation (= 10 mm jour -1) ont été identifiées comme une source importante de …  Lire la suite

To state the reasons for undertaking the present investigation it is necessary first to refer to the main chemical changes known to occur during the activity of skeletal muscle. The picture of these changes, since what A. V. HILL (106) has aptly termed 11 the revolution" can be expressed briefly as follows : Immediately following stimulation, the essentialnature of which is for the most part not understood, phosphagen breaks down anaerobically into creatine and phosphoria acid, providing most if not a11 the energy necessaryfor contraction and tending to lower the H ion concentration of the muscle. [...]  Lire la suite

Lewis (1) discovered active nitrogen in 1900. He observed that when nitrogen at low pressure was subjected to a condensed discharge, a yellow mist filled the discharge tube and diffused into the connecting tubes. On breaking the current, a yellow afterglow persisted for several seconds. He showed that this afterglow gave a banded spectrum which could be identified with part of the N2 spectrum, in contrast to the continuous emission spectra observed by earlier workers in afterglows in air and other mixed gases.  Lire la suite

Carnevale, Franco (Supervisor)  Lire la suite

This thesis describes the creation of a dynamics model of an autonomous underwater vehicle. Motion equations are integrated to obtain the position and velocity of the vehicle. External forces acting on the vehicle, such as hull and control plane hydrodynamic forces, are predicted for the full 360° angle of attack range. This enables the simulation of high angle of attack situations. An accurate through-body thruster model is also incorporated into the simulation. The vehicle model is validated using experimental turning diameters of the ARCS vehicle.  Lire la suite

The regulation of any fishery depends for its direction upon the knowledge of the biology of the fish involved. The flying fish, Hirundichthys affinis, is the main source of animal protein available to the 210,000 people living on the island of Barbados. This is only the first in a series of studies sponsored by the Barbados Government in the attempt to intelligently regulate this essential fishery. This work deals with the development of the flying fish from the freshly fertilized egg up to the young fish about 10 days old and about 15mm. in length. Methods of identification of the …  Lire la suite

The purpose of this study is to review and to correlate the factors involved in the scarring of cerebral tissue. Such a review of cerebral cicatrixin its manifold forms and causations should help in an understanding of the histological processes involved. Furthermore, careful analysis and theapplication of experimental methods should help to differentiate and to identity the late changes which follow cerebral insults of one form oranother. Finally, a clearer understanding of the mechanism of production of the various end results of cerebral insults may guide the way toimprovement in therapeutic measures, both medical and surgical. The work included in …  Lire la suite

Meakins, Jonathan (Supervisors)  Lire la suite

Topological quantum computing is an approach to the problem of implementingquantum gates accurately and robustly. The idea is to exploit topological propertiesof certain quasiparticles called anyons to obtain a proposed implementation of quan-tum computing which is inherently fault-tolerant. The mathematical structure thatdescribes anyons is that of modular tensor categories. These modular tensor cate-gories can be constructed from the representations of certain algebraic objects calledquantum groups. In this thesis we give an explanation of modular tensor categoriesand quantum groups as they relate to topological quantum computing. It is intendedthat it can be read with some basic knowledge of algebra and category …  Lire la suite

Bergthorson, Jeffrey (Supervisor2)  Lire la suite

Rigler, Frank (Supervisor)  Lire la suite

Hibbert, H. (Supervisor)  Lire la suite

Two series of recollection micropuncture experiments were performed on the dog kidney to assess renal handling of magnesium. Proximal tubule fluid was obtained before and after isotonic saline infusion and magnesium chloride. Tubule fluid-to-plasma (TF/P) inulin ratio was depressed after infusions of saline and magnesium chloride, whilst the tubule fluid-to-plasma ultrafiltrate TF/UF magnesium ratio approximated to unity. Fractional excretion of sodium and magnesium showed a parallel increase after saline, but after magnesium chloride infusion fractional excretion of magnesium far exceeded that of sodium. Further recollection micropuncture studies were performed during extracellular volume expansion and magnesium sulphate and chloride infusions with …  Lire la suite

Gilles Deleuze makes a paradox of ethics. Throughout his oeuvre, he establishes polarities (affirmation versus negation, difference versus identity, rhizome versus arborescence, etc.), and demonstrates rhetorically a preference for one pole over the other. This would seem to constitute, if not an obligation or imperative, at least an urgency, a suggestion that those who find his discussion compelling should favor that one pole and act in such a way as to promote it or move toward it. However, for a variety of reasons, it proves difficult or even impossible to put this 'ethics' into practice. This thesis examines the reasons …  Lire la suite

The prediction of mean end-to-end delay of multiple packet messages is the focus of this thesis. The models established are of great importance to network designers as they provide the basis for meeting user requirements for time delays and for network throughput. Two distinct models are developed depending upon the traffic load requested by network users. The first model considers traffic conditions in which the traffic demand heavily loads the computer network. Mean end-to-end message delays are computed by assuming the existence of product form solution of the obtained closed queueing network model. Heuristics are developed and are validated via …  Lire la suite

Ricard, François (Supervisor)  Lire la suite

Rapagna, Socrates (Supervisor)  Lire la suite

Mader, Mary (Supervisor3)  Lire la suite

While most people would agree that economic development is an important goal, and understanding of exactly what "economic development" implies, and how to achieve it, are considerably more elusive. Specifically, this paper addresses the concern about whether very small-scale "grassroots-style" development projects for producers--especially petty artisans--really have the potential to make a positive impact on an ailing economy. A case study of a textile weavers' project in rural northern Chuquisaca, Bolivia, among the Jalq's (Quechua-speaking) ethnic group, is presented in detail. The local-level organizations, known as "workshops", which administer this project are analysed along with economic data from households, in …  Lire la suite

Questions about the role of the "informal sector" color much of the discussion of urban economic development in poor countries. Why is there an informal sector (and how to define it)? Are informal businesses stagnant or dynamic, and can they contribute to development? In the small Bolivian city of Sucre, site of this study, there is no "informal sector"; rather, the entire economy demonstrates informal characteristics. With a handful of exceptions, businesses are all very small and household centered. Most manufacturing is done by hand or with simple machines, and informal labor and trade relationships predominate. This thesis describes Sucre's …  Lire la suite

L'étude des électrons dans de faibles dimensions est un domaine qui a donné un aperçu incroyable dans les dernières décennies du Effet Hall quantique fractionnaire de Wigner cristallisation . Au cours des dernières années, l'intérêt s'est développé à partir de l'étude de la physique fondamentale des deux conducteurs dimensions à l'ingénierie expérimentale nouveaux Etats à l'aide de techniques de la nanotechnologie . Nous avons maintenant la possibilité de créer de haute qualité et un zéro dispositifs dimensions , c'est- fils quantiques et boîtes quantiques . A des températures très basses , la physique quantique domine le comportement de ces dispositifs …  Lire la suite

Les établissements d'enseignement sont de plus en plus reconnus comme étant des entités culturelles qui peuvent être alignées ou en désaccord avec les valeurs culturelles personnelles des élèves (Fryberg, Troop-Gordon et al., 2013). Les désaccords entre ces valeurs culturelles semble etre une des raisons principales explicant l'écart de réussite scolaire entre les élèves autochtones et les élèves de d’autres cultures (Burack et al., 2014; Fryberg et al., 2018). Ces désaccords nuisent aussi à l’expérience, à la motivation et à la performances des élèves. Afin de mieux comprendre comment améliorer les taux de réussite scolaire chez les jeunes autochtones, cette thèse …  Lire la suite

During an earthquake, friction between opposing walls of a fault generates heat that dissipates slowly due to the low thermal conductivity of rock. This generates a melt layer that quenches into a “fossil earthquake”: an extremely fine-grained rock called pseudotachylyte. As earthquake source depths cannot be observed directly, the study of exhumed pseudotachylyte can ground-truth hypotheses on earthquake dynamics arising from theoretical, seismological, and laboratory experimental studies. High-velocity friction experiments have shown that frictional melt impacts the fault’s mechanical properties, initially acting as a lubricant, but once the melt begins to cool, it acts as a viscous brake to fault …  Lire la suite