McGill University Thèses et mémoires publiés en 2007

Conventional Minimum-Variance (MV) channel estimation is affected by two sources of error, namely the finite number of samples used to estimate the covariance matrix and the asymptotic bias due to interference and additive noise. On the other hand, widely linear (WL) filtering has been shown to improve the estimation of improper complex signals. Researchers have recently demonstrated that the application of WL processing principles can significantly improve the performance of subspace-based channel estimation algorithms. However, in contrast to MV estimation algorithms, subspace-based algorithms assume knowledge of the total number of users in the system, and must be coupled with sophisticated …  Lire la suite

This thesis deals with constructivist and English School accounts of humanitarian intervention. Literature from both of these schools contends that a "norm of humanitarian intervention" has emerged, whereby states should intervene to end massive human rights violations within other states. Accordingly, this thesis concerns itself with "norm entrenchment," the extent to which a norm has become sufficiently ingrained as to affect behavior. Specifically, this thesis examines the role played by norm entrenchment in bringing about US intervention and non-intervention in Somalia (1992-1993), Rwanda (1994), and Kosovo (1999). By assessing norm entrenchment at the individual, domestic, and international organization levels, this …  Lire la suite

The effects of vitamin E (VE) and Arginine (ARG) on humoral and cellular immunity in chickens were investigated in two experiments. The humoral immunity was measured by antibody responses to sheep red blood cells (SRBC) and maternal antibody titers to the infectious bursal disease virus (IBDV), while the cellular immunity was studied using the cutaneous basophil hypersensitivity test to phytogemagglutinin (PHA) and by counting subpopulations of T-lymphocytes. We used two levels of ARG: normal (NARG, 1.2% in feed) and high ARG (HARG, additional 0.3% in drinking water or 1% in feed in experiments 1 and 2, respectively); and three levels …  Lire la suite

The high number of Giardia cyst polluting surface water, in conjunction with the inadequacy of current water treatment practices in ensuring the complete removal of giardial cysts, has led our group to propose the use of CWP2-based transmission-blocking vaccines as a mean to control environmental contamination by reducing the spread of infective Giardia cysts in nature. In this PhD thesis, three key studies were performed with the ultimate goal of developing and testing a CWP2-expressing transmission-blocking DNA vaccine in the mouse model of the disease. The study presented in manuscript I examined for the first time the host's local immune …  Lire la suite

Les populations pauvres des regions rurales des pays en développement sontconsidérées comme étant particulièrement vulnérables. Les recherches passées ontdémontré que les membres de ces populations tendent à vivre dans des environnements àrisques et font face à de plus grands défis parce qu'exclus du filet de sécurité socialeformel et parce que possédant comparativement moins de biens mobiliers et immobiliers.Aujourd'hui, de beaucoup s'inquiètent de la contribution de ces risques, en particulier desriques environnementaux, à perpétuer la pauvreté et du danger qu'ils posent pour lemaintient des modes de vie. Malgré ces inquiétudes, notre compéhension desimplications des risques environnementaux pour les modes de vie …  Lire la suite

Plant sterol-containing food products are known to reduce low density lipoprotein (LDL) cholesterol, with the degree of placebo-adjusted reduction ranging from 5% to 15%. Factors that affect plant sterol efficacy such as the type of formulation and dosing frequency are still to be determined. Thus, the objective of this thesis was to investigate the impact of novel plant sterol preparations, frequency of intake and time of intake of plant sterols on cholesterol kinetics and/or plasma lipid profile. Three randomized, placebo-controlled, single-blind, crossover, supervised feeding trials were conducted in 75 subjects with LDL levels of > 3.0 mmol/L. The results from …  Lire la suite

Processing of petrochemical compounds produces a large amount of wastewater. This wastewater consists of toxic (hazardous) materials that can not be discharged to the environment without treatment. As restrictive environmental constraints increase, new technologies are needed to treat those toxic materials before discharging them to the environment. Wet Air Oxidation (WAO) is one of these new methods. This study casts light on the effect of initial pH on the WAO of benzene at different temperatures and pressures. It was found that at pH 6, a temperature of 260°C and a partial pressure of oxygen of 1.38 MPa around 97% degradation …  Lire la suite

This thesis addresses the problem of producing three-dimensional constrained Delaunay triangulated meshes from the sequential two dimensional MRI medical image slices. The approach is to generate the volumetric meshes of the scanned organs as a result of a several low-level tasks: image segmentation, connected component extraction, isosurfacing, image smoothing, mesh decimation and constrained Delaunay tetrahedralization. The proposed methodology produces a portable application that can be easily adapted and extended by researchers to tackle this problem. The application requires very minimal user intervention and can be used either independently or as a pre-processor to an adaptive mesh refinement system. Finite element …  Lire la suite

A technique was developed to study the effect of surfactant (frother) on individual bubble motion in swarms. The technique was based on high speed cinematography and tracking of multiple moving objects. Image processing algorithms were implemented in Matlab to isolate and measure geometric properties of the bubbles in image sequences recorded at 1 ms interval; and these properties were compiled into a data structure. To track a bubble, the geometric properties and a matching criterion were applied on consecutive pictures to identify the bubble. The bubble trajectory was reconstructed from the data structure for the matched objects. To maximize the …  Lire la suite

The notion of communication complexity was introduced by Yao in his seminal paper [Yao79]. In [BFS86], Babai Frankl and Simon developed a rich structure of communication complexity classes to understand the relationships between various models of communication complexity. This made it apparent that communication complexity was a self-contained mini-world within complexity theory. In this thesis, we study the place of regular languages within this mini-world. In particular, we are interested in the non-deterministic communication complexity of regular languages. We show that a regular language has either O(1) or O(log n) non-deterministic complexity. We obtain several linear lower bound results which …  Lire la suite

Viennese Expressionism 1909-1913 encompasses parallel evolutions in the disciplines of visual arts and music. Ideas from fin-de-siecle Vienna's intellectual milieu inspired the awakening of the Modern artist, from Ur-schrei to the formation of a new aesthetic theory. In this thesis, I examine the origin of iconic Expressionist aesthetic values and their technical expression in works by Arnold Schoenberg, Egon Schiele, Oskar Kokoschka, and Wassily Kandinsky. Topics covered are divided into two broad thematic categories whose central tenets originate in preoccupations with, on the one hand, an emerging understanding of the unconscious and psychic pathology; and on the other hand, the …  Lire la suite

Do welfare and social service provisions affect the childbearing decisions of Anglophone single mothers living below the low-income level in Montreal? Neoliberal rhetoric has asserted that increased welfare generosity will ultimately breed dependence on social services and propagate a lack of self-sufficiency for single mothers. Rather than a direct cause-and-effect relationship between welfare generosity and the birthrate of single mothers relying on welfare, my evidence suggests a weak correlation: while these provisions may alter the context in which childbearing decisions are made, they do not solely or primarily determine the outcomes of a pregnancy. By altering the economic context in …  Lire la suite

Carbon Nanotubes are thought to have tremendous potential as reinforcements for the next generation of composite materials. In the past decade, the enhancing effects of the nanotubes on the mechanical, electrical as well as multi-functional properties of polymer composites have been reported. However, the same nanotubes/polymer composites investigated by different research groups, in many cases, do not show a good agreement with one another. The root cause of this variability is believed to lie in the processing methodology employed to prepare the composites. Before one can propose an ideal and systematic processing condition, it is imperative to have a fundamental …  Lire la suite

Clinical chemistry is a medical discipline whose aim is to diagnose and assess disease by analysis of biological specimens. Modem laboratories can perform several hundred different tests using many different methods developed over the last century. The classical, more traditional assays are typically labour-intensive, not multiplexed (only measure one analyte or disorder per assay), expensive, require a long turnaround time, and may not provide adequate sensitivity and specificity. Developments in mass spectrometry (MS) and related technologies over the last two decades have provided solutions for many if not all of these shortcomings. While MS based applications have not yet been …  Lire la suite

The HPV E6-p53 interaction is well-understood, but not for all high-risk HPV types. In addition, HPV E6 p53-independent functions are gaining recognition for their importance in cellular transformation but require clarification. Thus, the aim of this study was two-fold: (1) to gain insight into the p53-E6 interaction for high-risk HPV-33 and, (2) to explore how high-risk HPV E6 proteins targets cellular MAGI-3 for degradation. In vivo and in vitro results indicated that E6 from HPV types 18 and 33 interacted similarly with p53 although, variants of the HPV-33 E6 prototype demonstrated interesting disparities. Of note was HPV-33 E6 variant 2, …  Lire la suite

Quantitative analysis of Drosophila melanogaster gap gene expression data reveals valuable information about the nature and strengths of interactions in the gap gene network. We first explore different models for fitting the spatiotemporal gene expression data of Drosophila gap gene system and validate our results by computational analysis and comparison with the existing literature. A fundamental problem in systems biology is to associate these results with the inherent cause of gene regulation, namely the binding of the transcription factors (TF) to their respective binding sites. In order to relate these expression-based estimates of gap gene regulation with the sequence-based information …  Lire la suite

Les hydrates gazeux, aussi connus comme des «clathrates d'hydrate », sont des complexes crystallins non-stœchiométriques ayant l'apparence de la glace, mais composés d'une structure différente. Ils se forment quand des molécules d'eau se lient grâce aux liens hydrogène pour former des cavités qui peuvent être occupés par un gaz ou un liquide volatil. L'introduction de ces molécules «invités» stabilise la structure formée par les molécules d'eau. Les hydrates sont une nuisance pour l'industrie de développement de gaz parce qu'ils peuvent obstruer les pipelines et équipements, ce qui interromperait les opérations quotidiennes et ajouterait aux coûts de maintenance. Dans cette étude, …  Lire la suite

Le broyage mécanique est une technique hors équilibre qui permet la fabricationde nouveaux alliages avec des propriétés exceptionnelles. Lors de cette recherche, unbroyeur SPEX 8000 a été utilisé pour développer une nouvelle classe denanocomposites à base d'aluminium et de magnésium. Ces nanocomposites tirent leurspécificité de leur dispersion de nanocrystaux dans une matrice amorphe. Duzirconium a été ajouté aux alliages d'aluminium et de magnésium pour promouvoirl'amorphisation. Les échantillons de poudres broyées ont été recuits à 400°C pour 1heure pour évaluer la stabilité thermique des différentes phases. Leur évolution a étécaractérisée par diffraction par rayon-X et par MEBIEDS. TI fut démontré que …  Lire la suite

Objective. The objective of this study is to test the efficacy of the biodegradable mesh as an alternative fixation device to the titanium mesh for support of onlay particulate, bone and cancellous, marrow (PBCM) grafts. Two parameters were evaluated: (1) Bone graft volume maintenance; and (2) Calcified tissue surface area and distribution. Methods. 12 New Zealand white rabbits were used and divided equally into two groups. In both groups, endochondral, cancellous bone graft was harvested from the anterior ilium. The bone graft was then compressed and placed as an onlay onto the lateral aspect of the mandible using two chambers …  Lire la suite

Neonatal ventral hippocampus (nVH) lesioned animals show molecular and behavioral abnormalities analogous to those described in schizophrenia. As an extension to previous studies that showed an increase in ligand binding of cortical alpha-1 adrenergic receptors (AR) and a dysfunction in alpha-1 AR regulation of mesolimbic dopamine functions in post-pubertal nVH lesioned rats, we investigated the subcellular expression and activity of protein kinase C (PKC)---a second messenger in alpha-1 AR signaling---in the prefrontal cortex (PFC) and nucleus accumbens (NAcc) of post-pubertal nVH lesioned rats. Western blot analysis of membrane and cytosolic fractions showed complex changes in lesioned animals in the expression …  Lire la suite

Waveform Relaxation methods are very efficient and reliable methods. They have been widely used in several fields, including circuit theory, for solving large systems of ordinary differential equations and solving partial differential equations. A new approach called optimized waveform relaxation algorithms was recently introduced which greatly improved convergence by using new transmission conditions. These conditions are responsible for the exchange of information between subsystems. In this thesis, we demonstrate that the transmission conditions have a tremendous influence on the convergence of the waveform relaxation algorithms for circuit simulations. We first derive new waveform relaxation methods for a general circuit and …  Lire la suite

A review of the literature indicates a facilitative effect of emotional content on communicative abilities in aphasia, including discourse production (e.g., Bloom, Borod, Obler, & Gerstman, 1992; Bloom, Borod, Santschi-Haywood, Pick, & Obler, 1996; Landis, Graves, & Goodglass, 1982; Ramsberger, 1979; Reuterskioeld, 1991). To explore how emotional content influences discourse-level pragmatic features in narratives produced by Arabic-speaking adults with aphasia, Grice's (1975) pragmatic framework for discourse analysis was adopted. The primary question addressed by the current study was whether or not discourse elicited using stimuli with emotional content (positive or negative) is superior in quantity, quality, relevance, and manner than …  Lire la suite

This thesis is a step forward in evaluating insulin therapy and defining its role in cardiac surgery first described as Glucose-Insulin-Potassium (GIK) solution 40 years ago. Chapter (I) includes a review of the literature on insulin therapy in cardiac surgery and illustrates the scientific bases and controversies in this therapy. Chapter (II) entitled: "Myocardial Protection During Elective Coronary Artery Bypass Grafting Using High Dose Insulin Therapy" represents a manuscript that was presented in the following meetings: (A) Local meetings: (1) McGill cardiovascular research day, February 1/2007, Montreal, Canada. (2) Fraser Gurd annual research day, McGill surgery department, May 31/2007, Montreal, …  Lire la suite

Distinct brain regions process innocuous vibration and cutaneous heat pain. The role of these areas in the perception of pain is still a matter of debate; and the role of these areas in the mediation of memory of somatosensory stimuli is uncertain and has not been studied with brain imaging in healthy human volunteers. All experiments described here, involved an experimental design, which included a delayed-discrimination paradigm and functional magnetic resonance imaging (fMRI). In manuscript #1, we aimed at unraveling the cerebral correlates of attention and spatial localization of innocuous vibrotactile stimuli applied to the right volar surface of the …  Lire la suite

The aim of this study is to revise existing theories of the Imamite turn towards rationalism. In the first chapter I discuss trends in Imamite thought during the period of the presence of the Imams; explore the impact of the Occultation on the Imamite community; and assess the character of the Imamite traditionism in the century after the Occultation. The bulk of the second chapter comprises a comparison of two texts: I`tiqadat al-imamiyya by Ibn Babuya, which represents Imamite traditionism during the first century of the Occultation, and Tas&dotbelow;h&dotbelow;ih&dotbelow; i`tiqadat al-imamiyya, which is a correction to Ibn Babuya's creed by …  Lire la suite

Le diabète pré-gestationnel et le diabète de gestation (DG) augmentent le risque dedéveloppement d'une future résistance à l'insuline et de diabète de type 2 autant pourla mère que pour l'enfant. Le stress oxydatif est un facteur potentiel impliqué dans ledéséquilibre du glucose sanguin associé au diabète de type 2 et au syndromemétabolique. La présente thèse est une étude sectionnelle croisée, ayant pour but demesurer des marqueurs du stress oxidatif, notamment la concentration des oxystérolsgénérés par les radicaux libres dans le sérum d'adolescentes, nées de mères ayantprésenté ou non un diabète de gestation. Nos résultats montrent des concentrationsd'oxystérols (7P-hydroxycholesterol) plus élevées …  Lire la suite

We present a system architecture and a set of control techniques that allow heterogeneous software design tools to collaborate intelligently and automatically. One of their distinguishing features is the ability to perform concurrent processing. Systems based on this architecture are able to effectively solve large electromagnetic analysis problems, particularly those that involve loose coupling between several areas of physics. The architecture can accept any existing software analysis tool, without requiring any modification or customization of the tool. This characteristic is produced in part by our use of a neutral virtual representation for storing problem data, including geometry and material definitions. …  Lire la suite

Les émissions anthropogènes de gaz à effet de serre sont la cause principale de l'augmentation globale des températures. Les changements climatiques vont affecter la production agricole au Canada, et en retour, l'agriculture pourrait limiter les changements climatiques. L'analyse de données historiques du climat et des rendements de maïs, combinés avec des expériences de serre et en champ ont été entreprises pour étudier l'effet de la variabilité et des changements de climat sur le rendement de maïs, l'adaptabilité des systèmes agricoles aux changements climatiques, l'effet du travail du sol sur les émissions de gaz à effet de serre (C02 et N20) …  Lire la suite

Objective. Most biomarker studies of maternal smoking have been based on a single blood or urinary cotinine value, which is inadequate in capturing maternal tobacco exposure over the entire pregnancy. This thesis used maternal hair biomarkers to investigate the association between maternal active and passive smoking, and birthweight for gestational age (BW for GA). Methods. Subjects were 444 term controls drawn from 5,337 participants of a multi-centre nested case-control study of preterm birth in Montreal. Maternal hair, collected after delivery, was measured for average nicotine and cotinine concentration across the pregnancy, assuming hair growth of 1 cm/month. The BW for …  Lire la suite

Optimized slender and short-thick beams are used in building, aircraft and machine structures to increase performance at a lower material cost. A previous work proposes an optimum shape, material and size selection model to design lightweight slender beams under pure bending. In short-thick beams, the transverse shear effects are no longer negligible and impact the choice of the optimum shape. This work extends such an optimum selection model to consider both slender and short-thick beams, by formulating the total beam stiffness design requirement as a combination of shear and bending stiffness. Selection charts are developed to show the impact of …  Lire la suite

Two experiments were carried out to evaluate the effects of Pearl Millet in combination with different levels of flaxseed and natural pigment (Oro Glo 15RTM) on quantity of n-3 fatty acids in eggs, laying performance and yolk pigmentation. In the first experiment, six different diet treatments were used for six weeks, with 24 hens per treatment (three birds per cage, eight cage replicates). Control diet was a corn-soybean meal diet, and diets containing 0, 2, 4, 8 or 12% ground flaxseed in which all the corn was replaced by pearl millet. In the second experiment, the diet treatments consisted of …  Lire la suite

L'environnement cosmopolite montréalais s'enrichit et se modifie au fil des annéesavec la mobilité des populations et l'arrivée de nouveaux immigrants. Dans ce contexte,il apparaît essentiel de connaître le développement des représentations culturelles desimmigrants en lien avec leur propre identité culturelle, et envers la langue française et lesgens qui parlent cette langue. Pour le milieu de l'enseignement du français, une telleconnaissance est essentielle pour susciter le développement de curriculum répondant auxbesoins langagiers et culturels des immigrants. L'éducation en langues secondes peutdonc fournir des opportunités pour mieux connaître l'Autre, sa langue et sa culture, etéventuellement pour permettre de le comprendre et de …  Lire la suite

As modern integrated-circuit (IC) technology advances, the level of integration increases, and so too does the clock speed of on-chip signals. As a result, signal integrity has become a major issue on which the circuit performance is largely based. Clock jitter is one of the main issues of signal integrity, and it has become one of the most important circuit limitations. While extensive research is on-going to reduce clock jitter in ICs, researchers have also been actively involved in discovering ways to characterize it through applications of new time measurement units, or TMUs for short. A number of TMUs have …  Lire la suite

This thesis explores how musical recordings circulate within various sites of metacultural analysis, such as print music publications, music blogs, community-based campus radio music programmes and music podcasts. Drawing on theories about cultural production, the circulation of cultural objects, and metaculture (circulation of ideas about cultural objects, rather than the objects themselves), the author traces how an independent record label discursively positions musical recordings for movement towards and within these meaning-making spheres. Print music publications and music blogs facilitate recognition and consecration of recordings in different capacities, particularly in relation to music publicity. Community-based campus (c/c) radio and music podcasts …  Lire la suite

In 1997, the UK's Labour government introduced several health policy changes, including plans for greater collaboration with private providers. Building on previous cross-sectional research, we explore longitudinal inequities in physician access as these policy changes were materializing. Using GEE models we examine the effect of income and private health insurance (PHI) coverage on access to physicians in the general UK population from 1997 to 2003. The study finds no income inequities in GP access. In contrast, those in the highest income quintile are more likely to access consultants overall (OR:1.10, CI: 1.01,1.19), particularly private consultants (OR:2.49, CI:1.80,3.44). Not surprisingly, PHI …  Lire la suite

Cyclical thrombocytopenia (CT) is a rare hematological disease characterized by periodic oscillations in the platelet count. Although first reported in 1936, the pathogenesis and an effective therapy remain to be identified. Since besides fluctuations in platelet levels the patients hematological profile have been consistently normal, a destabilization of a peripheral control mechanism might play an important role in the genesis of this disorder. In this thesis, we investigate through computer simulations the mechanisms underlying the platelet oscillations observed in CT. First, we collected the data published in the last 40 years and quantified the significance of the platelet fluctuations using …  Lire la suite

Sans etoiles is a musical composition in three movements written for clarinet, horn, violin, cello and piano. This essay deals with the principal characteristics of the musical material used in the piece, the modalities governing transitional processes and the influence of these factors on memory and the perception of musical time. The artistic project gave way to a reflection on the directional aspects of music in order to establish transitional links between independent musical entities defined as 'musical objects'. The main transitional agent between these entities consisted of an autonomous musical layer bearing an exclusive impact on the surrounding musical …  Lire la suite

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 …  Lire la suite

The sub-nanosecond dynamics of a two-dimensional electron gas (2DEG) are studied in conditions of high fields and low temperatures. Three main regimes are identified. Firstly, the propagation of sub-nanosecond, or GHz, signals in a 2DEG waveguide at low temperature (2 K) and high magnetic field (9 T). Here we show that the 2DEG waveguide can be fully parameterised by the Hall resistance and a new 'microwave scaling constant'. Secondly, the physics of plasmons confined at the edge and in a magnetic field (9 T): edge magnetoplasmons (EMPs). Here we resolve multiple plasmon modes, where as well as the standard EMP …  Lire la suite

Transparency and access to information have become important elements of the Mexican political transition. The goal of this study is to contribute to the debate on those fields by: first, providing a theoretical framework that helps to understand the notions of transparency and access to information and their linkage to a democratic regime; second, by offering an account of the institutions that preceded the enactment of this norm; and third, explaining the legislative work that led to the approval of the Transparency and Access to Governmental Information Federal Law (LFTAIPG) in Mexico in 2002. This thesis/paper argues that the LFTAIPG …  Lire la suite

Le mycoparasite Stachybotrys elegans est un agent potentiel de lutte biologiquepour le contrôle de Rhizoctonia solani, un phytopathogène causant le chancre dela tige et des stolons chez la pomme de terre (Solanum tuberosum). L'expressionde deux gènes induits pendant le mycoparasitisme a été étudiée chez S. elegans,alors que le mycoparasite était en interaction avec son hôte, R. solani, et un nonhôte,Sclerotinia sclerotiorum en utilisant la PCR quantitative en temps réel. Desanalyses comparatives ont démontré que les différentes formes d'hyphes et desc1érotes, ainsi que la présence de l'hôte ou du non-hôte, induisent différentspatrons d'expression. Le gène codant pour la calmodulin (calmodulin) ne …  Lire la suite

X-ray scattering is an ideal technique to perform measurements on the structures of materials. In the present thesis we use x-ray reflectivity (XRR) to study the structural properties of layers and multilayers. A trilayer system of CoFe-Ru-CoFe used for spin valve multilayers is investigated and the changes in structural properties induced by different procedures such as changing the Ru spacer layer, oxidation of the Ru spacer layer and annealing the sample are studied. Also, we study the electron density, thickness and optical index of refraction of samples prepared by glancing angle deposition (GLAD) method. We investigate the porosity in these …  Lire la suite

To generate profit and support high volumes of traffic, IP backbone networks are required to provide efficient scalable end-to-end Quality of Service (QoS) for a variety of telecommunication services. Scalability is achieved by using class-based QoS provisioning approaches such as Differentiated Services (DiffServ), while efficiency requires the appropriate use of traffic engineering mechanisms such as those provided by Multi-Protocol Label Switching (MPLS). This thesis presents a delay-margin based Traffic Engineering (TE) approach to provide end-to-end QoS in MPLS networks using DiffServ at the link level. The TE, combines mapping flows to routes, mapping routes to QoS classes, and the definition …  Lire la suite

La découverte accélérée de nouvelles molécules thérapeutiques qui ciblent lesmécanismes de progression du cancer tels que l'invasion et l'angiogenèse, nécessite lamise au point et la validation de techniques efficaces qui permettent d'évaluer l'efficacitéthérapeutique de ces agents in vivo. Le développement récent des scanners detomographie à émission de positron (TEP) dédiés à l'imagerie de petits animaux(microPET, CT! Concorde R4), permet aujourd'hui d'obtenir une image fonctionnelle etmoléculaire de haute résolution des modèles rongeurs. Cette étude s'intéresse au potentieldu 18F-2-fluoro-2-deoxyglucose (FDG) en utilisant l'imagerie microPET dansl'évaluation de l'efficacité de nouveaux agents thérapeutiques dans un modèle de gliomechez le. rat. Cette technique pourrait éventuellement …  Lire la suite

Nous considérons, dans cette dissertation, les plans d'expérience bayésiens optimauxpour les problèmes de point de rupture avec changement d'espérance. Un cas de pointde rupture avec changement d'espérance à une seule trajectoire se présente lorsqu'uneséquence de données est prélevée le long d'un axe temporelle (ou son équivalent) etque leur espérance change de valeur. Ce changement, s'il survient, se produit à unendroit sur l'axe inconnu de l'expérimentateur. Cet endroit est appelé "point derupture". Le fait que la position du point de rupture soit inconnue rend les tests etl'inférence difficiles dans les situations de point de rupture à une seule trajectoire.  Lire la suite

Plusieurs études ont récemment démontré la tolérance immunologiquedes cellules souches stromales (CSS) issues de rongeurs et de porcinés. Pour confirmer cesrésultats chez les cellules humaines, l'étude actuelle évalue l'effet des CSS humaines sur larégénération du myocarde chez des rats immunocompétents et étudie la possibilité d'utiliserces CSS comme « donatrices universelles» à la suite d'un infarctus.  Lire la suite

Le gène troponin I rapide (TnIfast) est un member d'une famille de gènes multiple don't les members s'expriment d'une façons differente celon le type de fibre du muscle squelettique. La spécificité pour le type de tissue et le type de fibre du gène TnIfast est due a un "intronic regulatory element" (IRE) situé dans le premier intron. Le IRE est un enhancer de 148 bp qui contient quatre éléments-cis connus; E-box, MEF2, CCAC et le CAGG elements. Une étude précédente dans notre laboratoire a suggeré que la spécificité du gène troponin I rapide pour le type de fibre est due …  Lire la suite

Linear precoding can be viewed as a convenient way to enhance the throughput and performance of a Multi-Input-Multi-Output (MIMO) communications system for its linear nature that facilitates its low-complexity implementation in a transceiver. Nevertheless, linear precoding designs usually assume instantaneous channel responses perfectly known at the transmitter, which is unrealistically difficult (if not impossible) in fast time-varying channels. An alternative to the assumption of full channel state knowledge is to consider the availability of partial channel knowledge at the transmitter, including information that changes much slower than the instantaneous channel responses such as the channel statistical parameters. The work presented …  Lire la suite

In order to investigate bubble formation and growth at 1 atmosphere, degassing experiments using a Stromboli basalt with dissolved H2O or H2O + CO2 were performed in a custom furnace on a beamline at the Advanced Photon Source. The glasses were synthesized at 1250°C and 1000 MPa, with ~3.0 wt%, ~5.0 wt%, or ~7.0 wt% H2O or with mixtures of H2O + CO2, ~3.0 wt% H2O and ~440 ppm CO2, ~5.0 wt% H2O and 880 ppm CO2, ~7.0 wt% H2O and ~1480 ppm CO2, then heated on the beamline while recording the bubble growth. The 3D bubble size distributions in …  Lire la suite

This research sought to explore the meaningfulness of belonging to a choir. Members of 14 Canadian choirs (N=404) responded to 18 statements concerning the perceived benefits of choral singing. Choristers ranked six aspects of choral singing in the following order of importance (from greatest to least): musical, intellectual, emotional, physical, social, and spiritual. An in-depth analysis of three central areas of the choral experience (social, intellectual, and emotional) was done and six sample populations were compared: paid vs. volunteer choristers, choristers living in different areas (urban, suburban, and rural), choristers with a music degree vs. non-degree, age of choristers (young …  Lire la suite