McGill University Thèses et mémoires publiés en 2003

Iron, known for its versatility, is an essential element in the metabolism of mammalian cells. One of the most common iron disorders is autosomal recessive disease---hereditary hemochromatosis, which leads to the iron overload in population of northern European descent. During years of my graduate research, I focused on the study of Hemochromatosis gene Hfe and a point mutation C282Y that leads to more than 80% of all hemochromatosis cases. Iron Regulatory Proteins (IRPs), which serve as main posttranscriptional regulators of cellular iron homeostasis, are the other interest of research. Iron regulatory proteins reversibly interact with iron regulatory elements (IREs) within …  Lire la suite

The activation of the protein tyrosine kinase (PTK) ZAP-70 is fundamental to T cell receptor (TCR) signal transduction. TCR engagement induces raft-association of ZAP-70 and juxtaposes the cytoplasmic ZAP-70 with the raft-enriched Lck, which phosphorylates and activates ZAP-70. The active ZAP-70, cooperatively with Lck, initiates multiple intracellular pathways eventually leading to T cell activation and IL-2 production. Here, we describe the serine phosphorylation on ZAP-70 on the highly conserved S520DVWS524 motif, and investigate its role in coupling ZAP-70 with TCR signal transduction.  Lire la suite

Future wireless systems will have to support multimedia services such as voice, data and video. Issues in providing multimedia services on wireless systems include multiple access, bandwidth rationing, scheduling and power control. In this thesis, we address the last issue. CDMA is assumed to be the access method. Each of these services has different Quality of Service (QoS) requirements, maximum power and packet time-out constraints; in order to achieve the required QoS, they can alter their transmission. In this work, we present a novel Power Control With Priority Scheduling (PCWPS) algorithm for a wireless CDMA system, which achieves reliability and …  Lire la suite

Due to the anthropogenic activities, the increasing carbon dioxide concentration in the atmosphere is disturbing the natural equilibrium of the greenhouse gas, and causes the global temperature rise. In 1990, the CO2 emission from fossil fuel fired power plants contributed 30% of global emissions. In the same year, the cement industry contributed about 5% of the total. According to Kyoto Protocol, a tremendous effort is required to reduce the carbon dioxide emission. One potential technology in CO2 mitigation responses is the use of concrete products as carbon sink through the early age fast curing. The cement compounds C3S and C2S …  Lire la suite

Various sources on Kazakh history demonstrate that a Kazakh culture was generated out of the predominantly pastoral experiences of its people. For centuries, Kazakh communities were engaged in a definite set of practices prescribed by pastoralism. Firmly incorporated into the all-Union structure of Soviet republics, Kazakhstan made an impressive transformation from a predominantly pastoral to an agroindustrial region with one of the most vibrant economies in Central Asia. Sovereignty in 1991 pushed the historic trajectory of the Kazakh nation further ahead, prompting its citizens to engage in self-reflection, and attuning their collective memories to a new set of social and …  Lire la suite

This thesis is concerned with development and implementation of an efficient and numerically reliable positioning algorithm based on the combination of code pseudorange (C/A) and carrier phase (L1) measurements with cycle slip detection. In GPS a typical technique for kinematic position estimation is relative positioning where two receivers are used, one receiver is stationary and its exact position is known, the other is roving and its position is to be estimated. We describe the physical situation and give the mathematical model based on the difference of the measurements at the stationary and roving receivers. The model we consider combines both …  Lire la suite

The Warsaw Convention 1929 is the first international instrument relating to private international air law. It established a certain uniform set of regulations in the field of international carriage by air. This widely accepted Convention was later amended and supplemented by several instruments in order to adjust and adapt this uniform set of rules to the rapid growth of aviation industry. With the absence of consolidation, the result was total confusion created by the coexistence of multiple legal regimes of the Warsaw System. To modernize and consolidate the instruments of the Warsaw System into one single instrument, the Montreal Convention …  Lire la suite

The objective of this research was to examine the effects of plant sterols and glucomannan on lipid profiles, plasma plant sterol levels and glycemic control in mildly hypercholesterolemic subjects. Thirteen type 2 diabetic and sixteen non-diabetic individuals participated in a randomized crossover trial consisting of 4 phases, of 21 days each. During the study period, subjects were supplemented with plant sterols and/or glucomannan. Overall reductions of total cholesterol and low-density lipoprotein (LDL) cholesterol concentrations were greater after consumption of plant sterols and glucomannan compared to plant sterol or glucomannan supplementation alone. Plasma lathosterol levels, indicators of cholesterol biosynthesis, were decreased …  Lire la suite

This phenomenographic study explores the intentions, ideals, and practices that shape educational leaders' conceptions of curriculum integration. The study uses documents and interviews to analyse the integrative elements of three of Quebec's key educational reform documents: The final report from the commissioners of the Estates General on Education; Reaffirming the mission of our schools: Report of the task force on curriculum reform ; and the Quebec Education Program. Fifteen curriculum reform leaders who participated in the process of drafting these documents were interviewed about their conceptions of curriculum integration. The conceptual framework used to study Quebec's conceptions of curriculum integration …  Lire la suite

Instant noodles are becoming popular in North America due to some recognized factors such as ready-to-eat convenience, acceptable taste and preferred texture. These factors are created by the interactions of certain ingredients including water, starch, gum and others. This research aims to investigate the ingredients effect on dough rheology and its relationship with qualities of instant noodles. Fundamental and dynamic tests were used to evaluate dough rheology. Relevant parameters include Young's modulus (E), energy at break (EB), storage modulus (G') and phase angle (delta). Increasing moisture content of noodle dough decreased its Young's modulus, energy at break and storage modulus. …  Lire la suite

Objective. To examine the temporal change in fetal death risk in the U.S. from 1991 to 1997 and to assess the extent to which changes in registration practices and labor induction have contributed to that change. Setting. United States. Design. Cohort study. Participants. All singleton pregnancies 20--43 weeks of gestation in 1991 and 1997. Main outcome measure. Fetal death risk (fetal deaths per 10,000 fetuses at risk at each completed gestational week). Results. From 1991 to 1997, the overall fetal death rate fell from 77.7 to 67.8 per 10,000 total births. However, fetal deaths at 20--22 weeks as a proportion …  Lire la suite

The Enhanced Dynamic Wedge (EDW) is an intensity modulated radiation therapy technique found in certain linear accelerators used in radiation oncology. Invoking the EDW causes one collimating jaw to move across the field to produce a predefined wedged dose distribution. Measured dose profiles were compared with plans calculated by a treatment planning system for various fields. EDW fields were examined for various wedge angles currently available for clinical use. EDW fields for non-clinical angles, which are not currently available, were also produced by applying the ratio of tangents method and delivered with the use of the Dynamic Beam Delivery (DBD) …  Lire la suite

Against the background of Indonesia's ethnic resurgence and social cleavage in the wake of the fall of Soeharto regime in mid-1998, this thesis seeks to identify the factors that have led to a particular incidence of this discord: the perceived inequity in access to economic and governmental resources, i.e., access to jobs in the public sector and to public health services. Taking modernization theory as its framework, the thesis compares the ascribed factor, i.e., Javanese or non-Javanese ethnicity, and certain other factors, i.e., level of education, region of origin and place of residence (urban or rural area) and evaluates the …  Lire la suite

The purpose of this study was to examine the perceptions and practices of children, their parents, and their teachers with regards to bullying at the grade school level. Eight children were interviewed; three that were identified by their teachers as victims, two identified as bullies and three identified as regular peers. Three parents, each taken from the victim, bully, peer groups were also interviewed, as was four teachers taken from the fifth and sixth grade, within the English and French language stream program. The subjects were interviewed using a semi-structured qualitative interview format. Victim children were generally perceived negatively by …  Lire la suite

Using numerical simulations, we design and analyze the performance of gain-clamped discrete fiber Raman amplifiers. In particular, we investigate a configuration which generates a feedback signal through the use of fiber Bragg gratings. We examine the impact of the feedback wavelength on the gain-clamping properties. From the simulation results, we conclude that in order to achieve uniform gain-clamping across the DWDM band of interest, the optical pumps must be depleted evenly by the feedback signal. The effect of the feedback signal on the amplifier may be mostly predicted based on the Raman gain coefficients corresponding to the frequency separation between …  Lire la suite

A series of studies is described here which explore the functional organisation of face- and object-processing neurones in the adult vervet monkey brain. This fundamental issue in high-level vision is addressed by the use of a novel molecular mapping technique that was developed for this purpose. In the first study, the temporal dynamics of c-fos and zif268 expression were delineated in detail in the rat visual cortex. Knowing the precise temporal parameters of up-regulation (after onset of sensory stimulation) and down-regulation (after offset of sensory stimulation) of these genes was integral to optimising the temporal aspects of the stimuli to …  Lire la suite

The purpose of this project is to develop an algorithm that speeds up large scale simulations of many-body systems. A numerical method is implemented that simulates non-equilibrium phenomena on a mesoscopic time scale. A system is perturbed by an external force, and time averages of variables renormalized in space are calculated numerically, using results of linear response theory, as the system relaxes to equilibrium. The coarse-grained variables evolve slowly in time, allowing one to advance them on a mesoscopic time scale. The algorithm was tested on two physical systems: a lattice confined ferromagnetic Ising model and an off-lattice Argon-like molecular …  Lire la suite

The permanent mold casting process is a relatively popular and effective casting technology that can produce near-net-shape aluminum components with integrity, particularly for the automotive and aerospace industries. It is well recognized by the casting industry that it is essential to control the cooling of permanent mold castings in order to improve the quality of the castings, so there is a considerable incentive to develop a more effective method of mold cooling to control the temperature distribution of the mold and the casting. The current technologies for controlled cooling are air or water cooling passages and chill inserts. Each of …  Lire la suite

XML has been extensively adopted by the industries for data exchange in the E-business environment. XML web service is XML based application, which can be used to integrate distributed applications. The objective of this thesis is to present the Web Service Architecture in detail, explore the use of XML and Web Service technologies for collaborative application integration in Business-to-Business, design and implement a Stock Information Service with the XML web service architecture. In this thesis, we start with an overview of current application integration approaches, and then focus on the Web Service Architecture. After exploring XML Web Service Standards, including …  Lire la suite

This thesis focuses on the historical development and user interfaces of editor tools, by comprehensively analyzing the features and characteristics of text editors, graphics editors, and spreadsheets. Terminology for user and user interface hardware is introduced, and the evolution of user interfaces of editor tools is discussed. In conclusion, observations about future editing tools are presented.  Lire la suite

This thesis presents an image based falling snow rendering method which is based on spectral synthesis technique. By incorporating the natural falling snow motion property, that is, the image speed and size of the snowflakes are related to the depth, we develop a tent-like surface in frequency domain. We synthesize the power spectrum along the tent-like surface and use IFFT to bring the data function back to space-time domain, thus attain a motion parallax image sequence. Treating the motion parallax as an opacity function, we can composite it with an existing video sequence and turn it into a snowing scene. …  Lire la suite

We consider the design and performance of CDMA-based multiuser detectors with partial information. Specifically, we assume that the multiuser signal presented to the receiver is contaminated by interference from sources whose parameters — power, delay, signature sequence — are unknown. The application we have in mind is to the uplink reception problem in CDMA cellular wireless, it being reasonable in such a setting to suppose that detailed parametric models of out-of-cell interferers may not be available to every base station. In the first part of the thesis, we propose forms of enhanced multiuser detectors with partial information, whose front end …  Lire la suite

Speed-o-Cam, a family of speed-reduction mechanisms based on cams and pure-rolling contact, is currently under development at McGill University's Centre for Intelligent Machines. This family is intended to replace gears and harmonic drives in applications where backlash, friction, and flexibility cannot be tolerated. In this thesis, we focus on the internal and external planar Speed-o-Cam with both positive and negative actions. We introduce 2-4-6 and 2-4-6-8 polynomials to modify the cam profile around both the cusp and the blunt point of the profile to improve the cam dynamic and kinematic performance. In a third approach, we resort to a cubic …  Lire la suite

The implication of active caspase-6 in the cell death of human primary neurons was studied in the present project. The importance of caspase-6 was confirmed by the fact that direct microinjection of recombinant active caspase-6 causes a protracted cell death in human neurons. Furthermore, an AD-related insult, intracellular amyloid beta (Abeta)1-42 delivered by microinjection of Abeta peptides, induces a rapid cell death mediated by caspase-6 in human neurons in primary cultures. Based on the hypothesis that decreasing or suppressing neuronal loss by inhibiting neuronal cell loss may benefit early AD patients in retaining cognitive capacities and preventing or delaying disease …  Lire la suite

Caenorhabditis elegans" locomotion consists of long forward crawling interrupted by short spontaneous reversals. We identified several intrinsic and extrinsic variables that influence the reversal frequency. In particular, reversal frequency can be transiently suppressed by touch. The genes glr-1 and nmr-1, which encode subunits of AMPA- and NMDA-type glutamate receptors, play a central role in touch-induced reversal suppression. Thus, reversal behavior is a motor output reflecting the integration of sensory inputs that display a form of memory. Food has a dramatic effect on reversal frequency that depends on chemosensation. Wild-type worms dramatically reduce reversal frequency on food but chemosensory mutants do …  Lire la suite

Dam safety is always a high priority issue since failures result in severe property damage and loss of life. Many countries require that all existing dams need to be inspected and evaluated regularly. Monitoring instruments have long been an integral part of the dam safety process by providing information for detailed analyses as well as for monitoring the current condition of dams. In this thesis, statistical models are used to infer behavior characteristics of a multiple arch dam. First, a statistical model known as the Hydrostatic-Season-Time (H-S-T) model is fitted to each individual displacement component from pendulum data for the …  Lire la suite

Anthony Giddens' ideas on modernity and globalization show that globalization is modernity at the global level. The three characteristics of modernity: time-space separation, disembedding of social systems, and reflexivity have all been intensified in the last twenty years. Globalization is, on one hand, pulling different cultures together to form a global world; on the other hand, diversifying and fragmenting the social contexts of human activities. The modern individual struggles to adapt to the different social milieux he is involved in and finds it difficult to form a coherent identity. Modern social systems provide more security; it also creates risks of …  Lire la suite

Heat pipes have been investigated, developed and applied in many industrial fields since 1964. However, heat pipe technology is still a relatively new topic in high heat flux environments such as are encountered in the metallurgical and energy industries. This study focused on the development of a novel heat pipe that can be used under high heat flux conditions. The state of the technology prior to this study was that heat pipes were not suitable for high heat flux applications. Even though numerous patents have been granted for heat pipes and related applications, most are based on the basic concepts …  Lire la suite

In this thesis, we propose an optimistic concurrency control mechanism for XML database systems. Using concurrency control, multiple users can access a single XML document at the same time. Our mechanism uses the XML DOM data model which presents XML-based documents as trees. We take the ancestor/descendant relationship between nodes of such trees into account. We integrated our mechanism into the McXML native XML database system and evaluated its performance.  Lire la suite

In this research program two coupling beam specimens were constructed and tested under reversed cyclic loading. One specimen was reinforced with horizontal reinforcing bars and hoops in accordance with the design and detailing requirements for ductile beams. Another specimen was reinforced with diagonal reinforcing bars in addition to the horizontal reinforcing bars and hoops. The diagonal reinforcing bars were not locally confined by closely spaced hoops to see if there would be adequate confinement and anti-buckling resistance. Both the specimens had an identical span-to-depth ratio of 3.0. The testing results showed that the diagonally reinforced coupling beam had better performance …  Lire la suite

Organic thin film transistors (OTFTs) have been fabricated using four different semiconducting polymers: poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV), polyhedral oligomeric silsesquioxanes (POSS) poly (2-methoxy-5-(2'-ethyl-hexyloxy)-l,4-phenylene vinylene) (MEH-PPV-POSS), poly[N-(3-methylphenyl)-N,N-diphenylamine-4,4'-diyl] (poly-TPD), and polyhedral oligomeric silsesquioxanes (POSS) poly (N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine (poly-TPD-POSS). These OTFTs were fabricated on heavily doped «-type silicon wafers with thermally grown silicon dioxide layer was used as gate insulator. Except for MEH-PPV, the OTFTs studied in this work are the first for the above organic semiconductor materials. From results of current-voltage measurements, it was observed that the present OTFTs showed I-V characteristics of typical /^-channel thin film transistors. Some of the fabricated OTFTs showed …  Lire la suite

The graphical presentation of survival functions by the Kaplan-Meier method is very useful for reporting results from clinical trials or cohort studies. However, this method is based on the "intent to treat" approach that assumes that the exposure under study is fixed over time, as are the covariates that are in addition assumed to be balanced between groups. These situations are not often the case in observational studies, where the exposure may varies over time, and covariates may be both time-fixed and time-dependent. In this thesis, we compare two methods for estimation of the survival function with time-varying exposure to …  Lire la suite

Previous studies have shown fine sediment was removed from spawning beds when salmon dug nests and subsequent sediment deposition can re-clog the nests, which reduces intergravel flow and threatens egg survival. In the intensively logged Cascapedia watershed it is not known if there is enough sediment deposition to re-clog salmon nests. Furthermore, Cascapedia spawning beds are relatively silt-rich, whereas, the effect of fine sediment has been studied in rivers with sand-rich substrate. I evaluated if sediment-epositing events reduced intergravel flow and if these events inhibited egg survival. During the summer and fall 2001, sediment deposition into clean gravel occurred at …  Lire la suite

I started this project work in November 2001. After all the laborious work of literature review, data collection, data analysis and text writing, this thesis is completed. I am so appreciative ofall the people who have helped me making this possible. First and foremost, I acknowledge the supervision of Dr. Paul Allison, who is always a source of advice and assistance whenever needed. He dedicated so much time and effort to organize the step-by-step procedures ofthis project, to give valuable advices for each step, and to make sure that all the details have been taken care of. When writing this …  Lire la suite

The study was designed to develop a nutraceutical product from by-products of fish processing. Fish oil was extracted from mackerel tissues (skin, viscera and muscle) using hexane-isopropanol (3:2 v/v) and chloroform-methanol (2:1 v/v) solvent systems. An oxidative study was carried out to determine the best processing and storage conditions to minimize autooxidation of mackerel oil. Urea complexation was used to concentrate polyunsaturated fatty acids (PUFA) from the extracted fish oil. The urea complexation process was optimized to determine the best reaction conditions for high yield of the omega-3 fatty acids in particular, and total PUFA. Conjugated linoleic acid (CLA) was …  Lire la suite

The optimized synthesis of acyclic dialkoxy disulfides and aromatic polysulfides is described and their physical properties probed. A theoretical survey of dialkoxy disulfides and thionosulfites was undertaken in order to determine the most efficacious method for accurately modeling these compounds. In particular, the origin of the high barrier to rotation in the dialkoxy disulfides was determined to be due to a generalized anomeric effect resulting from two lone pair donations of each sulfur atom into each of their respective sulfur-oxygen antibonding orbitals. The origin of the high rotational barrier was also verified experimentally, in particular with respect to solvent and …  Lire la suite