McGill University Thèses et mémoires par auteur commençant par A

La chenille de Spodoptera exigua est capable de nourrir sur les plantes malgré ses défenses anti-herbivores, grâce à des enzymes salivaires. Un de ces enzymes salivaires capable de combattre les defenses, glucose oxidase (GOX), est aussi régulé par la diète avec laquelle la chenille se nourrit. Il est donc important d'identifier la réglementation des produits salivaires comme GOX. Ce projet vise à déterminer les tendances de transcription et d'activité enzymatique de trois gènes salivaires (Se1H, Se2J et SeGox) en réponse de différentes diètes. De plus, les régions en amont des gènes salivaires ont tentées être séquencer afin de trouver des …  Read more

Numerical investigations of fully-developed, turbulent, single-phase and gas-liquid, bubbly two-phase flows in straight ducts of arbitrary, but uniform, cross-sections are presented in this thesis. The main focus of this thesis is on the formulation, implementation, and demonstration of numerical procedures for computer simulations of the aforementioned flows in ducts of noncircular cross-sections.  Read more

Over the last decade, there has been considerable interest and success in the formulation of co-located equal-order Finite Volume Methods (FVMs) and Control-Volume Finite Element Methods (CVFEMs) for the prediction of fluid flow and heat transfer. This thesis is concerned with an evaluation and enhancement of some aspects of recent co-located equal-order FVMs and CVFEMs. In particular, the goals of this thesis are the following: (1) formulation and computer implementation of a co-located equal-order FVM that facilitates the evaluation and enhancement tasks; (2) evaluation and enhancement of iterative sequential and coupled-equation solvers; and (3) comparative evaluation of a recently proposed …  Read more

In this thesis, we investigate team optimal decentralized estimation and control of networked control systems (NCS). NCS refers to multi agent feedback control systems where agents are connected over a communication network. The salient feature of such systems is that the information is decentralized i.e., agents have different information and need to coordinate their actions to minimize a common system-wide cost. As a result, the separation between estimation and control does not hold ingeneral, and, therefore, even for systems with linear dynamics, quadratic cost, and Gaussian noise, affine control laws are not optimal in general. We start by highlighting the …  Read more

This thesis examines social and cultural influences on housing and community planning in the native reserves of Canada. Architects and planners have tended to ignore the socio-cultural legacy of native people for a variety of unjustified reasons: insufficient local research and study, lack of understanding or appreciation, and the iniability to successfully accommodate ancient experience in the problem-solving process; approaches and techniques which may well be adapted to the contemporary context are typically overlooked. Where reference is made in housing and planning reports to socio-cultural issues, no recommendations are given as to how to interpret or apply them. The study …  Read more

Understanding the dynamic electrical response of charged or uncharged hydrogel sandwiched in a parallel-plate configuration (fixed bottom plate and top floating plate) is vital if such a configuration is to be adopted as a bio-sensing platform or developed to characterize the rheological and physicochemical properties of hydrogels. Using an interferometric displacement device, this study measures small-amplitude electric-field-induced displacements (order of picometres to micrometres) in an hydrogel-embedded parallel plate configuration. It also measures the response to an impulse perturbation, and reports how the top-plate displacement amplitude and oscillation frequency reflect the hydrogel viscoelasticity and thickness.  Read more

Les composites de nano-émulsions-hydrogels sont souvent vantés comme des matériaux de choix pour la libération localisée et contrôlée d’ingrédients pharmaceutiques actifs hydrophobes (IPA). Les hydrogels sont concus pour réagir à des stimuli prédéfinis, tandis que les gouttelettes transportent les IPAs jusqu’aux sites de libération désirés. Cette thèse présente une interprétation fondamentale de ce type de composites en utilisant une combinaison de méthodes théoriques et expérimentales. La mobilité dynamique des gouttelettes de cétane stabilisées au SDS est mesurée en présence d’électrolytes et d’hydrogels. Les résultats sont ensuite interprétés en utilisant des théories capturant les effets de Marangoni et du stress visqueux …  Read more

Since the overall performance of the delta-sigma D/A converter is limited by the analog circuitry, the greatest design challenge when building the converter involves the implementation of the reconstruction filter. This thesis will cover the design and implementation of three monolithic reconstruction filters. The first is an audio band active-RC Butterworth filter which is realized using a leapfrog structure. The various issues related to this design are dealt with including design-for-testability circuitry and tuning circuitry. The next two filters are both implementations of a current steering semidigital FIR reconstruction filters. These implementations are meant to reveal an alternative approach to …  Read more

La connectivité est essentielle à l'unité et au progrès économiques, sociaux et politiques de l'Afrique. L'aviation civile est vitale pour l'unité et le progrès de l'Afrique parce qu'elle relie le continent plus rapidement, efficacement et en toute sécurité. L'Afrique rencontre cependant des obstacles uniques à l'utilisation et à la croissance des services de transport aérien sur le continent. L'accès restreint au marché par les transporteurs aériens affecte particulièrement la qualité et le volume des services de transport aérien sur le continent. Les États africains gouvernent généralement l'aviation civile séparément par des politiques et des instruments juridiques « centrés sur la …  Read more

Political Economy, from the beginning of the seventeenth century until the middle of the nineteenth, was largely preoccupied with the analysis of the nature, causes, and consequences of the increase in the wealth of nations. Indeed, this search for an explanation of the process of economic developnent is one of the main links in the history of economic thought. Undoubtedly, from the second half of the nineteenth century until the first half of the twentieth, there occurred a major shift in emphasis, that is, to value and distribution theory; but nevertheless, a substantial part of the work of writers even …  Read more

Grimard, Franque (Supervisor)  Read more

Cette thèse est sur la soutenabilité de l'espace et la nécessité de protéger l'environnement spatial à long terme. Elle traite du problème en regardant le régime de responsabilité civile spatiale, notamment en se penchant sur le fait qu'il ne tient pas compte des dommages causés à l'environnement spatial. Des leçons de jurisprudence peuvent être tirées des régimes actuels de responsabilité environnementale pour les activités dangereuses sur terre, pour protéger l'environnement spatial. Alors qu'il est reconnu qu'il y a des limitations dans les régimes de responsabilité tels qu'ils se présentent, si l'on remédie aux faiblesses inhérentes, la responsabilité environnementale pourrait être …  Read more

Il semble exister, dans la manière d'interpréter la liberté spatiale, une opinion dominante qui accorde peu d'importance à la notion d'un bien commun qui rend cette liberté possible. La complexité de la chose vient du fait que la notion de bien commun est elle-même ambiguë en soi. Cependant, cet avis dominant voit le problème du partage du bien commun dans le contexte des tensions évidentes entre les grandes puissances spatiales, les états émergents, et l'idée que la liberté prend un sens particulier dépendamment du niveau de développement. L'idée générale ne tient pas compte du fait que les solutions aux soucis …  Read more

Physical analogs to the statistical properties of a theoretical flicker noise model are extracted from published accounts of the character of the record. Analogies are drawn between the temporal scales of variability of sedimentary processes, and the spatial scales of acoustic impedance variability. A linear model is proposed as a first approximation. It is consistent with both impedance characteristics and the dual, cyclic spatial and episodic temporal, nature of the sedimentary record. This model consists of the superposition of independent random processes having logarithmically distributed correlation times. Processes occurring over some discrete frequency range define distinct scales of 'stability' in …  Read more

Computer simulations play an important role in the design and verification of space robotic operations since on-orbit tests are impossible to conduct before launch. Thus, accurate computer modelling and simulation of space robotic tasks is essential. Of particular difficulty are space manipulator operations, which involve constrained or contact tasks. Here, the contact dynamics capability in the modelling tools becomes critical for high fidelity simulation. This in turn implies a need for accurate determination of contact parameters, which are used as inputs to contact dynamics simulation. In this work, the identification of contact dynamics parameters based on sensor data obtained during …  Read more

Accurate Linear Prediction Coefficient (LPC) estimation is a central requirement in low bit-rate voice coding. Under harsh acoustic conditions, LPC estimation can become unreliable. This results in poor quality of encoded speech and introduces annoying artifacts. The purpose of this thesis is to develop and test a two-branch speech enhancement pre-processing system. This system consists of two denoising blocks. One block will enhance the degraded speech for accurate LPC estimation. The second block will increase the perceptual quality of the speech to be coded. The goals of this research are two-fold---to design the second block, and to compare the performance …  Read more

As Canada, and particularly metropolitan cities like Montreal, becomes increasingly diverse, it is important to explore and understand the culture and needs of immigrant communities. This Masters thesis focuses on the mental health of South Asian immigrant women in Montreal, Quebec. This original research is a qualitative descriptive study based on in-depth interviews with nine women from India and Pakistan. The interviews focus on the intersection of gender and culture with post-migration experiences, help-seeking patterns and coping strategies for distress in South Asian women. The women's narratives provide pertinent information for researchers and practitioners that could be applicable to the …  Read more

Hanley, Donal (Supervisor2)  Read more

The goal of this research is to explore the feasibility of building management information gateways that relay management information at regular intervals between the Simple Network Management Protocol (SNMP) and the Common Management Information Protocol (CMIP). This management information is stored in an object-oriented Management Information Base (MIB) that can be accessed by Common Management Information Service (CMIS) management applications. An approach for polling based on a variable polling frequency is proposed. A stateful model for a simple version CMIP proxy agent for SNMP which requires management information collected from SNMP agents to be stored in the proxy agent's MIB …  Read more

A total of 114,351 Holstein first lactation records collected by the Quebec Dairy Herd Analysis Service (DHAS-PATLQ) between September, 1979 and January, 1994 were used to study the effects of adjusting records for linear and quadratic effects of 90- and 305-d feed intake measures (total energy, total protein and total dry matter) on estimation of heritabilities of and genetic correlations among yield and composition traits. Genetic parameters of feed intake measures, relationships between feed intake and age and weight at calving, and feed conversion efficiency traits were also examined in a series of studies. A sire model fitted by REML …  Read more

Spin dynamics in solid state NMR and NQR are studied using spin density matrix theory. First, the response of spin 7/2 subject to the first order quadrupolar interaction, excited by one and two pulse sequences is examined. Specific pulse sequences with appropriate phase cycling designed for detection of MQ coherences developed during the first pulse are calculated analytically. The results are applied to the determination of quadrupolar parameters and true chemical shifts utilizing a ID nutation experiment. Solomon echoes under soft pulse excitation are also considered for spin 7/2. Second, analytical solutions of off-resonance nutation line intensities for spin 3/2 …  Read more

Les faisceaux Euler-Bernoulli vibrant avec une courbure uniforme sont sujets à une dilatation de leur matériel. En conséquence, cette dilatation cause des gradients de déformation à apparaitre à travers l'axe neutre. Le couplage thermoélastique transforme ces gradients de déformation en gradients de température qui provoque la conduction thermique irréversible, suivi par la génération d'entropie. Ce type de dissipation est nommé l'amortissement thermoélastique.L'étude de l'amortissement thermoélastique exige une solution à l'équation de conduction thermique. Pour les matières thermoélastiques, cela prend la forme d'une équation différentielle partielle non-linéaire. Les modèles linéaires sont déjà bien établis dans la littérature, pourtant les modèles non-linéaires …  Read more

Cette thèse explore la possibilité d’isoler, par immunoprécipitation, l’ARN lié par un lien covalent à eIF4E par la photochimie. Des expériences in vitro établissent que le lien formé entre eIF4E et l’ARNm lors du traitement à UV est spécifique pour son domaine responsable pour interagir avec la coiffe (cap) de l’ARNm et que ces complexes d’eIF4E-ARNm peuvent être immunoprécipités. En ajoutant l’épitope FLAG à l’extrémité N de eIF4E, on a pu améliorer la spécificité des immunoprécipitations, ce qui a été déduit par l’immunoprécipitation de lysats radioactive ( S³⁵). De plus, un mutant de eIF4E, G139D, a été caractérisé. Celui-ci a …  Read more

The stability of hydrogen peroxide (H2O2) is a critical factor for the brightening of mechanical pulps. Inorganic ions, including Fe, Mn and Cu catalytically decompose H2O2. These troublesome metals promote the rapid transformation of H2O2 to nonselective hydroxyl radicals that degrade the cellulose fibres and decrease yields. The interaction of aqueous metal•complexes with magnesium metal (Mg°) or bimetallic mixtures of magnesium with either palladium (Pd°/Mg°) or silver (Ag°/Mg°) were optimized to remove metals (Mn, Cu and Fe) from solution with concomitant release of the complexing reagent. The analyte metals were removed by both cementation on the surfaces of the excess …  Read more

The technology of supercritical fluid extraction (SFE) offers the opportunity to efficiently extract both relatively non-polar analytes as well as ionic materials (such as metal ions) that can be mobilized with the addition of complexing reagents. The nebulizer of a conventional flame atomic absorption spectrometer (FAAS) was modified to extend the range of metals amenable to on-line detection. The flow injection thermospray-FAAS (FI-TE-FAAS) interface provided efficient detection for a variety of less volatile elements (Co, Cr(III), Cr(VI), Fe, Ni, Mn and Al) present as ions in aqueous media or as complexes in the supercritical fluid (SC-CO2) carrier phase. The range …  Read more

Children form a bulk of the Canadian population, but have no control over the economic purse that decides their future. The "action-radii" of children between the ages of 6 years to 10 years is limited to the surrounding neighbourhood. This is also the age of physical exercise, emotional, social and full personality development in which play constitutes an important education tool. Over the years, the urgent need to create high-density housing led to subsidized housing projects. During this process, providing an ideal environment in which to raise children has been overlooked. So, what do the children do? Where do they …  Read more

Hovey, Richard (Internal/Supervisor)  Read more

Des recherches récentes en neuroimagerie ont démontré des variations dans les schémas neuronaux parmi différents groupes culturels et socioéconomiques, soulignant l’impact significatif de la diversité de la population sur le cerveau. Les méthodologies conventionnelles des neurosciences supposent souvent que les relations entre le cerveau et le comportement sont uniformes dans diverses sous-populations, occultant potentiellement des mécanismes neuronaux critiques spécifiques à certains sous-groupes. Pour répondre à cette question, nous avons analysé 35 phénotypes comportementaux, 13 sources de diversité et des données de neuroimagerie de l’ensemble du cerveau à l’état de repos réparties en 100 régions cérébrales, provenant de 11 875 participants …  Read more

Part A traces back the origins of the conflicting claimsto sovereignty over the area now called the West-Bank. The analysis shows that a sovereignty vacuum ensued after Turkey relinquished by treaty its rights and title over Palestine and that subsequently that vacuum remained in the area earmarked for an Arab Palestinian State. Part B peruses the constituent elements for the legality or illegality of the sovereignty claims invoked by the parties concerned: the use of force and the act of selfdefence. Part C demonstrates that Israel has eroded the law of belligerent occupation through a system of military orders, which …  Read more

One of the outstanding scholars of his time, Sayyid Haydar Amuli (719-787/1319-1385) played an important role in the development of Shii 'Irfan, a tradition which traces its roots back to the Prophet Muhammad and the Imams. He gave his attention to the subject at a time when the Shia Islam began to develop its characteristic set of doctrines through the efforts of 'Allama Hilli and his son Fakhr al-Muhaqqiqin in Iran and Iraq. Sayyid Haydar lived at a time of great political and social upheaval. This thesis places Amuli within this context and describes his life in some detail. Moreover, …  Read more

Les mécanismes par lesquels la situation socio-économique (SSE) pourrait influencer les maladies cardiovasculaires (MCV) ne sont pas bien définis. Les objectifs de cette étude sont d'examiner la relation entre la SSE au cours d'une vie et l'athérosclérose sous-clinique, telle que mesurée par le "Indice de Pression Cheville Brachial ABPI", aussi connu sous le nom de "index ABPI''. Les participants (n=1454) provenaient de l'étude de cohortes Framingham Heart Study Offspring. La SSE cumulative a été calculée en additionnant les résultats pour la SSE durant l'enfance (scolarité du père), la SSE durant la period le jeune et l'adolescence (sa propre scolarité) et …  Read more

Oligoribonucleotides comprising of 2',5' -linked internucleotide linkages are known to bind selectively to RNA over DNA. The ability to bind to RNA renders them suitable as probes for many biological applications, such as 'antisense technology'. Little is known about the effect of sugar structure (and conformation) on the binding properties of 2',5'-linked oligonucleotides. To get insight into the role of sugar conformation, 2 ',5'-linked oligonucleotides modified at the C3'-position of the furanose ring were synthesized via solid phase synthesis and their binding to complementary single stranded DNA and RNA was studied. Their application as antisense oligonucleotides was also evaluated. The …  Read more

Asgharian-Dastenaei, Masoud (Supervisor1)  Read more

We describe a general formalism for computing scattering rates of weak probes in macroscopic systems, based on a density matrix formalism. We show that weak probes in general scatter off fluctuations in the medium. In the limit that the neutrino wavelength is much larger than the lengthscale of the fluctuations, we show that the scattering rate can be calculated from knowledge of the equation of state of the medium through which the neutrinos travel. Using radial profiles of a post-bounce, shocked supernova core and a well-established equation of state for nuclear matter we compute these scattering rates for various times …  Read more

We review the lore of effective field theories as a background to hierarchy problems in general and the cosmological constant problem in particular. We outline some of the attempted four-dimensional solutions to the cosmological con stant problem and conclude that ones based upon the usual assumptions of four-dimensiona lfield theory typically do not work. We argue that one way to relax the assumptions is to seek solutions to the cosmological constant problem which rely on the presence of extra dimensions. We explicitly exhibit that standard compactification techniques fail to solve the cosmological constant problem because they reduce the problem to …  Read more

The Finite Element Method (FEM) applied to wave scattering and quasi-static vector field problems in the frequency domain leads to sparse, complex-symmetric, linear systems of equations. For large problems with complicated geometries, most of the computer time and memory used by FEM goes to solving the matrix equation. Krylov subspace methods are widely used iterative methods for solving large sparse systems. They depend heavily on preconditioning to accelerate convergence. However, application of conventional preconditioners to the "curl-curl" operator which arises in vector electromagnetics does not result in a satisfactory performance and specialized preconditioning techniques are required. This thesis presents effective …  Read more

Low circulating testosterone levels in the male are a major cause of hypogonadism and infertility and have been linked to mood changes, fatigue, osteoporosis, reduced bone-mass index and aging. The treatment of choice, testosterone-replacement therapy (TRT), reverses several symptoms of low testosterone levels. However, this treatment is linked to luteinizing hormone (LH) suppression, which leads to reduced fertility, increased risk for prostate cancer and cardiovascular diseases. Therefore alternate therapies with lower side effects are highly beneficial. The principal site of regulation of steroid hormone biosynthesis is the transfer of cholesterol from the outer to inner mitochondrial membrane (OMM and IMM, …  Read more

Gagnon, Claude (Supervisor)  Read more

Healthcare information is now accessible in online communities and distributed by several users who are sharing sometimes reliable information but also misinformation, often grounded in their personal experiences. In this shift in healthcare information sharing in online communities, we see new ways of interaction and unexpected individual outcomes. However, little is known currently on the use and impact of online communities in health care. This thesis proposes three essays to examine 1) peer support in offline and online communities, 2) the role of online communities in knowledge delivery to patients, and 3) the impact of online reviews on risk-sensitive decisions. …  Read more

This thesis presents advances in the design and control of direct drive systems. The McGill/MIT synchronous direct drive motor, a new high performance torque sensor, and a complete hydraulic dynamometer testbed are designed and built.[...]  Read more

La thromboembolie veineuse, comprenant la thrombose veineuse profonde et l'embolie pulmonaire, est une cause majeure de morbidité et de mortalité liée au cancer et ses traitements. Il est bien connu que l'apparition d'une tumeur maligne prédispose les patients à des troubles de l'hémostase. Les patients atteints de cancer ont un risque 6-7 fois plus élevé de thromboembolie veineuse par rapport aux individus sains. Cependant, les mécanismes régulant les interactions entre le cancer et la thrombose veineuse ne sont pas entièrement compris, principalement parce que les modèles animaux sont rares et nécessitent le sacrifice des animaux. Le développement de modèles animaux …  Read more

The Rule of Law is taken to express a straightforward idea: societies should be governed by laws rather than the whims of humans. More precisely, the Rule of Law expresses the idea that the State or sovereign exercises its power within the scope of limiting public norms, namely laws. However, its usage has been taken well beyond its traditional role of curtailing the power of the State or sovereign; it is inserted as a response to virtually every demand of the mainstream development agenda. Indeed, the Rule of Law has been overexpanded by an ever-growing list of development demands and …  Read more

Tabrizian, Maryam (Supervisor1)  Read more

Malgré les propriétés ‘d'autoguérison’ de l'os, les lésions osseuses non soudées, souvent appelées défauts osseux de taille critique (CSBD), peuvent résulter de conditions congénitales, résections tumorales et traumatismes(20). Des efforts marquants ont été récemment mis au point pour trouver un biomatériau pouvant servir d’échafaudage pour restaurer la structure et la fonction originale de l’os lorsqu'il est placé sur le site du défaut osseux. Bon nombre de ces biomatériaux échouent en raison du manque de ressources suffisantes d’approvisionnement vasculaire généralement présent dans la matrice osseuse d’origine(23). Par conséquent, le besoin d’un biomatériau approprié continue de grandir.L’objectif de cette étude est d’utiliser …  Read more