McGill University Thèses et mémoires publiés en 2002

Animals can associate orosensory characteristics from food with postingestive effects and adjust meal size to prevent energy deficit. By using odor-fasting duration conditioning, two studies were conducted to test the above hypothesis. In the first study, thirteen male and eleven female adult Wistar rats were given 1.5 hours to ingest a casein-based test-meal odorized by either vanilla or chicken flavor prior to a 4-hour short-fast or a 12-hour long-fast. Rats went through the training phase with a pseudo-random sequence of six duplicates of each odor-fasting pairing over four experimental days, followed by an odor preference test. Gender differences may exist …  Read more

Bajcsy, Jan (Supervisor)  Read more

Iron (Fe) plays an essential role in numerous metabolic processes. The transferrin receptor (TfR) is a cell membrane-associated protein that serves as a gatekeeper in regulating cellular uptake of Fe from transferrin (Tf) by TfR-mediated endocytosis. TfRs are expressed ubiquitously, but their highest levels of expression are on immature erythroid cells (which are the most avid consumers of Fe in the organism) and on rapidly dividing cells, both normal and malignant. In proliferating non-erythroid cells TfR expression is feedback inhibited by Fe through the interaction of specific binding proteins, iron regulatory proteins (IRPs), with iron responsive elements (IREs) in the …  Read more

Artificial cells microencapsulation have a number of potential areas of application. Studies showed that lowering of tyrosine level could inhibit the growth of melanoma. However, at present there is no practical method to lower the tyrosine level in humans. We have therefore devised novel methods as follows. (1) Microencapsulation of tyrosinase for the removal of systemic tyrosine by oral administration. Characterization, optimization, and feasibility studies were carried out to test the therapeutic potentials. In temperature and pH studies, the encapsulated tyrosinase maintained higher enzyme activity than the free enzyme in solution. The in vivo studies showed that daily oral administration …  Read more

RET is a tyrosine kinase receptor that induces cell survival, proliferation and migration. When bound by its ligand, GDNF (glial derived neurotrophic factor) and its co-receptor, GFRalpha-1 (GDNF family receptor alpha-1), tyrosine residues in the intracellular domain of the receptor are phosphorylated as part of signal transduction. In the kidney, RET is required for branching of the ureteric bud and it also regulates the maturation of the ureter in the urinary tract. Although it is well established in mice that the absence or overexpression of RET leads to severe kidney abnormalities, the cellular basis for these defects remains unexplored. To …  Read more

Chlorinated aromatic compounds are an important group of compounds. Many of them have been produced in large quantities and they are indispensable to technological and societal benefits. But regulatory agencies have tightened regulations on the use and release of chlorinated aromatic compounds because of the scientific understanding of their toxicity, persistence, behavior in the environment and their potential to cause adverse effects on the ecosystem and human health. Pentachlorophenol (PCP), octachloronaphthalene and decachlorobiphenyl are all highly chlorinated aromatic compounds, of which, PCP has been used mainly as a biocide. Octachloronaphthalene and decachlorobiphenyl don't have practical use, but their congeners have …  Read more

Apolipophorin-III (apoLp-III) is known to influence the haemocyte-mediated induction of antimicrobial peptides in Galleria mellonella and yeast phagocytosis, bind to Gram-negative and Gram positive bacteria and limit the activation of the haemocytes and the prophenoloxidase system by bacterial surface antigens. The effects of apoLp-III on haemocyte adhesion to glass slides and to bacteria were herein examined. ApoLp-III bound to haemocytes limiting the adhesion of both granular cells and plasmatocytes to glass and the contact of the plasmatocytes with Bacillus subtilis. The percentage of granular cells with bacteria was increased by the protein. However, the total number of bacteria adhering to …  Read more

Nepheline syenite represents the highly differentiated product of fractional crystallization in the Poudrette quarry at Mont Saint-Hilaire, Quebec. It also records a significant subsolidus overprint due to circulation of post-magmatic fluids. Annite, the ferrous-iron-dominant member of the biotite series, represents up to 20% of the typical nepheline syenites. Hand samples cover the complete range of freshness, from unaltered to hydrothermally modified rocks. Identification of minerals and estimation of their abundances and compositions were obtained with optical microscopy and electron-microprobe analysis. I also used a combined approach of X-ray diffraction and high-resolution transmission electron microscopy. With respect to annite composition, Fe/(Fe …  Read more

Joober, Ridha (Supervisor)  Read more

Gordon, Philip (Supervisor)  Read more

Case-based reasoning is a field of artificial intelligence research that emphasizes the importance of specific past experiences to the solution of new problem. The ability to suggest a solution to a novel problem based on the recall and reuse of specific experiences is a tenet of the case-based reasoning paradigm. It has grown out of cognitive theories concerned with functional justifications for the dynamic properties of human memory, and is growing into a technology for expert systems. Studies examining the use of cases in design have identified a broad range of application. This approach is well suited for the engineering …  Read more

The general bearing mode of failure often controls the capacity of cold-formed steel bolted connections loaded in shear. Previous research has shown that the absence of washers can significantly lower the bearing resistance of these connections. Experimental studies have also revealed that the bearing capacity can be formulated with a gradated bearing coefficient that is governed by the ratio of fastener diameter to sheet thickness. A gradated bearing coefficient method, which was based on an investigation of bolted connections composed of mild steel as well as thin high strength steel, has recently been proposed to cold-formed steel design code committees …  Read more

Current challenges facing us in developing dedicated positron emission tomography (PET) systems for metabolic breast mammography (PEM) and small animal (ANIPET) are to achieve high spatial resolution (less than 2 mm) and high efficiency. It is also crucial to extend the sensitive areas of PEM detectors to their periphery in order to overcome the difficulty in imaging near a patient's chest wall. This limitation of the periphery dead region was revealed in the clinical trials of our previously developed PEM-I system. In the new study, we developed prototype detectors by using position-sensitive photomultiplier tubes (PS-PMTS) and pixelated bismuth germanate (BGO) …  Read more

This thesis investigates the complexity of cultural translation of visual language, considering writing systems both a profound shaping force and microcosmic reflection of the central elements of its culture. It focuses on the case of Chinese pictogram in Western everyday fashion; fashion is treated here as a site where the conceptual, aesthetic and cultural dynamics vividly interact with one another. This work probes what tensions are lost and added to the pictograms' cultural meaning in the process of translation, bearing in mind the two different aesthetic philosophies underlining Western and Chinese calligraphies. Seeing the complexity in the change of tensions, …  Read more

In this study the gene expression pattern of a novel proteinase inhibitor II (PI-II) gene, PiA, in potato (Solanum tuberosum ), was analyzed using RT-PCR. The PiA gene was found to have enhanced expression in expanding tubers of a greenhouse-grown diploid clone (DC), different stages of 'Russet Burbank' tubers and expanding microtubers of in vitro-grown 'Russet Burbank' and 'Bintje'. PiA mRNA was more abundant in the tuber vascular ring and perimedullary zone areas than in other tuber tissues of DC. The PiA gene was also expressed in flower buds/flowers, shoot apices, leaf blades, stems and roots of 'Russet Burbank'. The …  Read more

A new, efficient image compression algorithm based on a rotating, overlapping, hierarchical representation (ROHR) is presented. This algorithm first decomposes the spatial image data into a hierarchical coordinate space, composed of interconnected nodes. The surprise of each node represents the entropy of the corresponding image area, and determines its significance in reconstructing the image. Surprises are ordered and transmitted in decreasing order of magnitude with a bucket encoding method, yielding an embedded code. ROHR allows for either lossless compression, or for termination of the encoding or decoding at any point to meet a target compression ratio or distortion metric. In …  Read more

This thesis contains a summary of previous cold-formed steel stud shear wall test programs in North America, as well as an overview of the seismic requirements for a number of different design standards, i.e. the NBCC, the UBC and the NEHRP guidelines for seismic design. A theoretical method for the prediction of shear capacity based on the first possible failure mode, which follows the adapted American wood design procedure, is presented and the results from this method are compared with peak loads obtained from existing tests. In addition, a preliminary force modification factor for use in seismic design is suggested …  Read more

Kar, S. (Supervisor)  Read more

This thesis documents the design and implementation of two enhancements to the Aldat database programming language: abstract data types (ADTs) and extensions to the domain algebra. Utilizing a nested relational model and an improved procedural abstraction facility, ADTs are declared as computations encapsulating states with their accessor/modifier methods. Objects of an ADT can be instantiated via a single join. As computation calls are embedded into updates and virtual domain actualization, objects are manipulated and accessed solely through the methods exported by the ADT. The vertical domain algebra empowers Aldat with the capability to combine values along a domain using system …  Read more

While plate tectonic theory has been developed considerably in the last four decades, the of initiation of subduction remains an enigma. In this thesis, I investigate the possible initiation of subduction of North Atlantic oceanic lithosphere at the Scotian basin off east coast of Canada. On the basis of the relationships between topography, gravity and magnetic anomalies, in both space and Fourier domains, a crustal model is proposed to explain the long- and intermediate-wavelength components of the gravity anomalies of eastern Canada which takes into account the topography, density perturbations in the crust and upper mantle and Moho undulation with …  Read more

Magnetic structure and magnetization reversal of lithographically patterned submicron and nanometer scaled magnets with elliptical, disk, ring shapes, and pseudo spin valve structures, were studied by magnetic force microscopy. Magnetic measurements were performed with a custom built vacuum magnetic force microscopy with in-situ in plane magnetic fields. The MFM has been optimized with a force gradient sensitivity as high as 1 x 10-6 N/m. By using various magnetic tips, operating in different modes, and studying different samples, the effect of the magnetic tip stray field induced distortion of the magnetic state of a submicron sized magnet is presented. Through the …  Read more

Hassani, F. (Supervisor)  Read more

This dissertation is a study of the political career and thought of Said Halim Pasha (1865--1921), a prominent Islamist thinker and eminent Ottoman statesman, set against the historical and ideological background of his time. The period covered in this study extends from the twilight of the Hamidian era to the end of the Ottoman Empire (1900--1922). During these two crucial decades, the Ottoman Empire, prior to its demise, went through an immense transformation. The establishment of the Constitutional regime in July 1908 allowed several ideological currents to circulate freely on the political scene and to compete in filling the vacuum …  Read more

The present study explores the relationship between language and architecture as symbolic systems against the background of the creation of independent Czechoslovakia at the end of World War I. It takes as its focus the Prague Castle, and the intent of the first President of Czechoslovakia, philosopher Thomas Garrigue Masaryk (1850--1937), to "democratize" the vast complex of historic structures that formed it, with the help of the Slovenian architect Joze Plecnik (1872--1957). To effect change in the charged, historically circumscribed spaces of the Castle can be viewed as a language analogy mainly in the terms of creating new relationships . …  Read more