McGill University Thèses et mémoires publiés en 1998

Neurodegenerative diseases are characterized by accelerated and/or inappropriate neuronal loss which is thought to be caused by genetic and environmental factors. At present predisposing factors remain unknown and effective therapies are not available for many of these diseases. However, recent work has described at least 4 pathogenic mechanisms. (1) Oxidative stress: mutations in the superoxide dismutase gene cause approximately 1% of ALS cases. (2) Neurofilament abnormalities: neurofilament overexpression causes an ALS-like phenotype in mice, while pathologically, neurofilament accumulation is observed in patients. (3) Deregulation of apoptosis: deletions in apoptosis-regulatory genes are present in spinal muscular atrophy. (4) Expansion of trinucleotide …  Read more

Non-small cell lung cancer (N-SCLC) is characterized by intrinsic resistance (appearing without drug selection) to chemotherapy treatments. Molecular mechanism(s) of this type of resistance are not fully understood. Using a panel of N-SCLC cell lines, we have demonstrated that upregulation of DNA repair is due, at least in part, to an overexpression of the tyrosine kinase receptor erbB-2. To explore the mechanism by which erbB-2 affects DNA repair regulation in N-SCLC, I examined the transcriptional regulation of three proteins involved in the early steps of the nucleotide excision repair (NER) pathway, namely XPA, XPB, and XPD, using vectors where a …  Read more

This work examines the effect of three emerging satellite technologies on the use and regulation of what might be called Earth Orbital Space. The three new technologies, Direct Broadcasting Satellites (DBS), Global Mobile Personal Communication Services (GMPCS), and Global Navigation Satellite Services (GNSS), are being implemented in or planned for different portions of Earth Orbital Space: the geostationary orbit, low earth orbits, and medium earth orbits, respectively. Each technology creates different challenges for the International Telecommunication Union which is the organization charged with their regulation. DBS services were regulated in the 1970s and early 1980s prior to their practical use. …  Read more

Despite the fact that phonological awareness (PA) is one of the strongest predictors of reading acquisition, relatively little is known about its origins and development. Theories of spoken word representation and cognitive control were examined to explore the respective roles of linguistic and cognitive factors in the development of PA following debate in the research literature regarding the linguistic versus cognitive basis of PA. Pre-literate, kindergarten children were administered tasks assessing PA, spoken word representation in long-term memory, phonological encoding in working memory, and cognitive control at the beginning and end of the kindergarten year. At the end of grade …  Read more

In this thesis, the waveguide design characterization for wide-band Ti : LiNbO3 Mach-Zehnder electro-optical interferometric intensity modulators (Z-cut substrate) has been performed using a combination of the effective index method and the 2D finite-difference vectorial beam propation method (FD-VBPM). For the passive aspect of the device, to minimize the propagation loss, the coherent coupling effect of radiation modes has been studied as well as the effectiveness of a cosine-generated Y-branch and a notched Y-branch in comparison with the conventional sharp-bend Y-branch. By making use of the coherent coupling effect on a notched Y-branch structure, a propagation loss figure of 0.145 …  Read more

Music depends on the perception and production of complex temporal patterns, or rhythms, as a vital part of its power to communicate. These experiments investigated the neuroanatomical substrate of rhythm perception and production in patients with focal cerebral lesions, and in neuroimaging studies with normals. The hypotheses focused on the role of the primary and secondary auditory cortex, as well as the cerebellum and other motor-related areas. Experiment I. To estimate the extent of removals in the region of auditory cortex in neurosurgical patients, a 3D probabilistic map of Heschl's gyrus (HG) was developed from magnetic resonance imaging (NW scans …  Read more

This thesis investigates properties of spaces generated by Peetre's K-method and uses the K-method to interpolate linear, quasilinear and Lipschitz operators. Variants of classical results such as the Riesz convexity theorem and the Marcinkiewicz Interpolation Theorem will be proved using the K-method.  Read more

The area investigated in this research is the groundwater basin of the valley of Tlacolula de Matamoros, of the central valleys of Oaxaca in Mexico. The objectives of this research were to consider together the causes and symptoms of the technical problems concerned with effective management of ground-water and related land resources in a semi-arid climate. The preparation of electronic basemaps and their field control is first investigated. A methodology for the preparation of multi-layer base maps is successfully established. The variability of climatic conditions and climatic trends that may affect the quantification of the design rainfall and the elaboration …  Read more

La presence de macropores entraine une infiltration rapide, dite préférentielle, de composes chimiques, tels les pesticides, a travers la zone vadose du sol. La plupart des études vis ant a caractériser le phénomène d'écoulement préférentiel à travers les macropores considèrent le sol tel une "boite-noire". Ainsi, il n'a pas encore été possible de décrire de façon quantitative l'effet de la géométrie des macropores sur cet important phénomène hydrologique. Quatre colonnes de sol (850 mm x 77 mm de diamètre) ont été prélevées intactes pour visualiser et quantifier la structure des macropores a l'aide d'un CAT scanner. La quantification des macropores …  Read more

Mechanical weed control, chisel plow tillage and organic fertilization are important components of sustainable agriculture that can contribute to the preservation and improvement of soil and water resources. These practices can each affect weed communities, crop weed interactions and crop yields. Little is known about their combined effects on weed populations and weed community dynamics in common cropping systems. The main objective of this project was to determine the effects of crop rotation, weed control, tillage and nutrient source and their interactions on weed communities and weed emergence. The field experiment was conducted on a Sainte-Rosalie clay and a Duravin …  Read more

Biological treatment of pulp and paper wastes by activated sludge is widely practiced in industry to reduce the organic content and toxicity of the wastewater. Most industrial applications require the treatment of a combination of streams from various processes. The composition of the combined stream varies since shock loadings and spills may occur. The objective of this research was to determine the effects of these variations on the microbial community and, ultimately, on the kinetics of the reduction of biological oxygen demand (BOD) and chemical oxygen demand (COD). This will improve the understanding of control requirements for the process. Effluents …  Read more

The human T cell leukemia virus type I (HTLV-I), the etiological agent of adult T cell leukemia is the first human retrovirus linked to malignancy. The viral protein Tax, is essential for HTLV-I gene transactivation and responsible for oncogenic transformation. Tax is capable of indirectly transactivating numerous growth regulatory genes through interactions with host transcription factors. One of the targets of the Tax protein is the NF-kappaB/IkappaB family of transcriptional regulators. In HTLV-I Tax expressing cells, the maintenance of NF-kappaB activity is essential for cellular transformation. Previous studies demonstrated that Tax activated NF-kappaB through binding to the Rel homology domain …  Read more

A new methodology using simple acid-base hydrolysis of aminosilanes with molecules containing terminal hydroxyl groups, has been developed for the preparation of supports for heterogenized homogeneous catalysis. The flexibility of this approach has allowed the build-up of new materials ranging from simple organometallic thin films to complex organometallic-inorganic sol-gel networks, and organophosphine and metallodendrimers. The acid-base hydrolytic route to construct thin films containing phosphine and amine donor ligands on glass surfaces, eliminates the problems of the traditional surface functionalization techniques. Surface modification involves the reaction of SiCl4 with the surface hydroxyl groups of glass, quartz and single crystal silicon, followed …  Read more

Lupines (Lupinus albus L.) can provide high levels of good quality protein for human and animal nutrition. Unlike soybeans, lupine seeds do not need to be processed before consumption. Being a member of the legume family, lupines improve soil structure and fertility. Lupines also have the advantage of being able to grow in cooler climates and in fields of lower fertility than soybean. Lupine production is relatively new in Eastern Canada and new diseases limit production in this region. In 1990, a Phoma sp. was isolated from diseased lupine in Quebec and Nova Scotia. This research was undertaken to acquire …  Read more

A study was conducted to examine the response to feeding flaxseed (FS) and probiotics on plasma and egg yolk cholesterol and plasma fatty acid profile in laying hens. A total of 576 Single Comb White Leghorn hens (SCWL) at 26 weeks of age were fed diets containing 15% FS and a corn-soybean meal diet (C) supplemented with and without ferlac 25 (F25) or Lactobacillus acidophilus (LA). Feed consumption was significantly (p < 0.05) increased by FS supplemented with both F25 and LA. Dietary treatments had no significant (p > 0.05) effect on feed conversion. Egg production was significantly (p < …  Read more

Under open access, market driven transactions have become the new independent decision variables defining the behaviour of electric power systems. Understanding the impact of these bilateral transactions on system losses and line loading is important for the secure operation of the network and for establishing equitable tariffs corresponding to actual network use. The theory presented here is based on the argument that it is always possible to compute the exact loss and line loading allocation corresponding to an infinitesimal variation in a bilateral transaction. This leads to a set of governing differential equations whose solution yields the exact allocation. Numerical …  Read more

The objective of this study was to estimate the relationship between survival at various stages of productive life (17, 30, 43, 55 and 96 months of productive life) and type traits in Quebec Holstein and Ayrshire cows. The original data set from the Programme d'Analyse des Troupeaux Laitiers du Quebec contained 559,203 lifetime records calculated from 2,237,081 lactation records including calvings from 1979 to 1995. Lifetime records containing type classification information provided by the respective breed associations were used to study true survival variables (opportunity to survive to 17, 302 43, 55 and 96 months) and functional survival variables opportunity …  Read more

Proinflammatory cytokines by Th1 cells and macrophages are involved in the pathogenesis of several organ-specific autoimmune diseases. Clinically, cytokine therapy has the potential of influencing disease outcome by altering the balance between proinflammatory versus immunosuppressive cytokine profiles. Somatic cytokine gene therapy is an attractive alternative to cytokine immunotherapy, because it eliminates the need for frequent protein injections, and generates more constant cytokine levels in vivo which may reduce toxicity and increase therapeutic efficacy. To study the immunoregulatory effects of TGF-beta1 and IL-4 in vivo, we used a novel method of i.m. cytokine gene therapy in 2 experimental models of Th1 …  Read more

The objectives of this research program were to provide evidence of the distinction between global and specific relational models and to assess their relative contributions in the experience of significant life events and daily social interactions. Relationship-specific models were operationalized in two ways: in terms of significant role relationships and in terms of salience (i.e., frequency of interactions). The association between global relational models and specific models, selected on the basis of the other's role (Study 1) or salience (Study 2), was examined. Results indicate that these constructs were correlated, but not redundant. Moderate stabitily of global and specific models …  Read more

Three studies were conducted to investigate the moderating and mediating influences of perceiver and target variables in the similarity-attraction relationship. In Study 1, 85 heterosexual males rated the interpersonal attractiveness and perceived attitude similarity of heterosexual and homosexual targets who were either attitudinally similar, ambiguous (i.e., no-attitude-information controls), or dissimilar to the participant. The relative effect of attitude similarity and attitude dissimilarity information on attraction judgments was moderated by the perceiver's prejudice level, but not by the target's group membership. Supplementary analyses revealed that target attraction ratings were only partially mediated by participants' perceptions of attitude similarity. Study 3 expanded …  Read more

This thesis is an analysis of Salman Rushdie's Midnight's Children, The Satanic Verses and The Moor's Last Sigh. The approach is twofold: (a) it seeks to establish an interplay between the concept of exile-in-narration (theme) and narrators-in-exile (form) as a reflection upon questions of rootlessness; and (b) it seeks to underscore this interplay as a recurring 'double bind' within each novel, such that the novels form a loosely bound trilogy that functions as a developing discourse on individual and national identity from a decentred perspective. The aim is similarly twofold: (a) it proposes that the metaphor of exile as a …  Read more

The space of appearance emerges from the practice of speech and action in the presence of others. Although it predates the public sphere as a formal construction, it exists in the context of a particular place. With the transformation of the ancien regime and the emergence of the bourgeois public sphere, the meaning of public and private was obscured by the rise of the 'social.' The public realm was transformed from a space of disclosure to a realm defined by the necessities of survival---a process by which speech and action lost much of their former power. In the spectacular relations …  Read more

Miniaturized titanium implants placed in the diaphysis of mouse femurs were used as a model to examine concurrent effects on bone marrow lymphocytes, while attempting to accelerate the osseointegration of titanium implants by applying human recombinant Transforming Growth Factor Beta1 (TGF-beta 1) in carrier medium to the implant site, prior to implant placement. While the response of lymphocytes to titanium implants has been addressed, at present, the response of these cells in vivo to TGF-beta 1 remains unknown. The use of double immunofluorescence to bind molecular markers has allowed the detection of the various phenotypic stages during B cell differentiation, …  Read more

An isocentric teletherapy cobalt unit provides a viable alternative to an isocentric linac as a radiation source for radiosurgery. An isocentric cobalt unit was evaluated for its potential use in radiosurgery in three areas: (1) the physical properties of its radiosurgical beams, (2) the quality of radiosurgical dose distributions obtained with 4 to 10 non-coplanar arcs, and (3) the accuracy with which the radiosurgical dose can be delivered. In each of these areas the 10 MV beam of a linear accelerator served as a standard for comparison. The difference between the 80%--20% penumbras of the radiosurgical fields of the cobalt-60 …  Read more

Many individuals with chronic or degenerative diseases in Canada are in receipt of long-term artificial nutrition and hydration. Once an individual has been transferred to a chronic care facility, is the feeding tube viewed as a medical treatment, and subject to the same evaluations and discussions as other medical treatments, or does the feeding tube become an unquestioned permanent part of the life of the resident? How do clinicians who care for these residents view the ethical issues involved in long-term tube feeding? Attitudes of physicians and health care professionals regarding the use and possible discontinuance of long-term tube feeding …  Read more

This paper is an investigation into the way that paranoia is represented in Thomas Pynchon's novel Gravity's Rainbow. Using various definitions of paranoia which are given in the text itself, I outline how each definition is demonstrated, both in narrative events and in the structural principles of the text. As well, I show how each definition may lend a different perspective on the reading process itself, thus implicating the Pynchon's reader in the paranoid dynamic which Gravity's Rainbow depicts. In effect, I attempt to return the pluralism to Pynchon's definition of paranoia.  Read more

The thesis describes a program of research aimed at exploring the consequences of confronting potential perpetrators of discrimination with their own prejudice. An experimental paradigm was introduced that involved confronting advantaged group members with their own potential prejudices in a series of two studies. In the first study, White participants who admitted to some prejudice were, surprisingly, also more likely to genuinely reflect on and challenge their prejudice. A second experiment investigated the interpersonal consequences of stereotype threat in advantaged group members. Male participants were confronted with the possibility of confirming the negative stereotype that "men are sexist". The results …  Read more

We have used thermal conductivity measurements at low temperature to probe the behavior of the unconventional superconductor YBa2Cu 3O7-delta (YBCO). Two aspects were investigated: (1) the in-plane anisotropy, studied in order to gain insight into the contribution of CuO chains, and (2) the effect of a magnetic field, investigated in order to explore the contribution of vortices. Our results on the low temperature thermal conductivity are in good quantitative agreement with the theory for a d-wave superconductor. We have found a very weak (or even negligible) anisotropy suggesting that the anisotropy could not simply be explained by mass tensor anisotropy …  Read more

This thesis describes the application of a Radio-Acoustic Sounding System (RASS) at an urban site, and proposes a Rank-Order Signal Processing Algorithm (ROSPA) to overcome the problems associated with that type of application. The main problem is clutter of many kinds contaminating the clear-air profiler measurements. ROSPA uses primarily order statistics, and operates in two main stages. The first stage operates on the clear-air Doppler velocity spectra by using a threshold minimum filter on the successive spectral power values at a given Doppler velocity bin for several spectra at a given altitude. The threshold minimum filter is a variant of …  Read more

Dini, Petre (Advisor)  Read more

This thesis examines the trope of anthropology in the Canadian poet Anne Carson's work. This trope functions as an extended metaphor to describe the study of cultures, texts, and the "alien countries" of other human souls. Anne Carson rejects anthropological practices that aim at the "invasion" of the other, and associates such practices with the actions of seeing, projecting and even "devouring." Instead she favours anthropological approaches that foster mutual "encounters", such approaches being typically charged with the actions of listening, absorbing and breathing. This distinction becomes crucial when we consider its implications for reading and writing about Anne Carson's …  Read more

The effect of acids and bases on the solubility of amino acids at 298.2 K, within the pH range (2--10) and out of the pH range was determined. The amino acids-studied were glycine, DL-alanine, DL-valine and DL-serine. The acids used were HCl and HNO3 and the bases NaOH and KOH. It was observed that in the pH range (2--10) there is no significant difference in the solubility of DL-alanine in the presence of different ions such as, Na+ or K+, at high pH, and Cl - or NO3-, at low pH. However, in concentrated acids the solubility is higher in …  Read more

This thesis examines the issue of the proper role of religious arguments in the political debate of contemporary democratic societies, characterized by pluralism and usually organized as secular states. To formulate this question, this thesis takes as a reference Chile's current political debate, in which some of the more contested political issues engage citizens' religious and ethical ideas and aspirations. To clarify the terms of the problem and explore the elements of an answer, this thesis resorts to the treatment of this issue in contemporary Anglo-American political and legal philosophy. This thesis tries to show that such restrictive views rests …  Read more

Post-inspiratory braking is the activation of inspiratory muscles during expiration. Although not energetically optimal, it exists for currently unexplained reasons. It has been postulated that post-inspiratory braking exists in order to maintain arterial CO2 content in a tightly regulated band. A computer simulation of the respiratory system incorporating respiratory control, respiratory mechanics, and gas exchange dynamics was developed in order to evaluate the relationship of post-inspiratory braking to arterial CO 2 content. The simulation was driven with pressure signals having varying amounts of post-inspiratory braking. No significant effect upon arterial CO 2 content was found. This suggests that post-inspiratory braking …  Read more

Potable water for some regions of the world is difficult or even impossible to find. However, some of these locations have salt water or brackish water and desalination can make this water potable. Currently, reverse osmosis, evaporators, and solar stills are used for this purpose. In this study, membrane distillation was examined and deemed to be a potential alternative. In this thesis, two polypropylene tubular membrane units were compared; they differed in membrane tube length and number of tubes. The system was configured for direct contact membrane distillation. The feed passed through the membrane lumen, while the cooling water passed …  Read more

This thesis argues that the interface between human and machine has been an important system of metaphors since the beginning of the twentieth century in North American science fiction (SF) and nonfictional writings. In examining these texts, this study intends to discuss positions and responses regarding technological developments and the social and political experiences underlying it In my parallel analyses of fictional (SF) and nonfictional (philosophical, scientific, theoretical) texts. I wish to signal similarities and differences among the two fields. In different ways, the treatments of cyborgs and cyberspace in both nonfiction and SF have addressed, through these metaphors, notions …  Read more

Japan and oriental art were great influences on some of Claudel's texts. A brief review of the origins of the Japanese short story and of the first encounters between Claudel and Japanese art precedes, in this essay, an analysis of Claudel's writing in this regard. Then, based on the poet's texts about Japan and/or reflecting his experience of Japan, we attempt to isolate major features of oriental writing: attention paid to emptiness and silence, different view on mimesis, purity and simplicity of style, settling of the subject, and eternity given by the creative act to fleeting moments. In conclusion, it …  Read more

The effects of exercise frequency on the stereotypic behaviours of four children with developmental disabilities were examined. Two exercise treatments were implemented, differentiated by frequency. The single frequency exercise treatment consisted of one daily 10 minute walk/jog session, while the multiple frequency treatment involved three 10 minute walk/jog sessions per day. Stereotypic behaviours were observed prior to the exercise sessions, as well as immediately following exercise. The results indicated similar reductions in stereotypic behaviours with the use of both treatments. In the single frequency condition, subjects demonstrated a mean reduction of 51.6%. These data confirm the results of past research, …  Read more

Guemhioui, Karim El (Advisor)  Read more

The quality of the strip produced in a near-net-shape casting process is strongly linked to the metal feeding system. An alternative metal delivery system was proposed and a comprehensive mathematical model, including heat transfer, fluid flow and stress studies was used as a tool to perform this task. This model included three-dimensional flows with fully coupled momentum and heat transfer. Turbulence effects as deduced from the standard kappa- 3 equations, macroscopic solidification, as well as flow through porous media were also modeled. A further simple model for stress was employed to calculate the displacements and the stress distribution throughout the …  Read more

A huge amount of data is present in the visual field of the primate visual system. Serial processing of the entire visual field requires long periods of time, while parallel processing involves very complex architectures. Biological systems are able to handle this problem using attention. Attention is a mechanism where interesting locations in a given scene, that are worthy of more processing, are identified. These locations are then serially attended to where the precious amount of resources are allocated for further parallel processing. Biological systems have been able to find a good compromise between the slow serial architecture and the …  Read more

Mermelstein, Paul (Advisor)  Read more

Huk, Olga (Advisor)  Read more

An optical technique for monitoring the solidification of thermoplastics in an injection moulding machine was implemented. The technique uses a He-Ne laser that illuminates the mould cavity, and a photomultiplier to measure the intensity of reflected light during the moulding cycle. Data from the sensor allows tracking the injection moulding cycle development. The measured light intensity is mainly influenced by refraction and reflection phenomena at the melt-solid interfaces during solidification. Reflection occurs primarily from the opposite mould wall but the reflection intensity is a complex composite of reflective scattering and refraction from crystallites, the mould wall and as many as …  Read more

A laboratory study was conducted to bioremediate a fine textured soil contaminated with diesel. The local microorganisms were stimulated by supplying nutrients with the aid of a water table management system. A fine textured soil, contaminated for more than 20 years, with more than 6500 mg/kg of diesel was packed in fifteen columns, 2 m long and 0.2 m in diameter. Twelve out of fifteen soil columns were subjected to bioremediaton, by supplying nutrients, water and air at desired depths. Three columns were used as a control to monitor passive degradation of contaminant without intervention. The experiment was designed to …  Read more

This dissertation focuses on slaves and peasants as self-consciousness actors in northwestern Sierra Leone between 1896 to 1956. During this period, which covers almost the entire duration of British colonial rule in the region, these subaltern groups used covert and violent actions to protest the various demands---labour, tribute and taxation---of the state and the local elite. Covert actions like evasions, escapes and migrations became interwoven into the fabric of colonial rule. Violent actions, which tended to be spasmodic, erupted when social and economic conditions deteriorated sharply. Four major rebellions occurred during colonial rule in region. The first, spearheaded by local …  Read more

Thus far, cellular automata have been used primarily to model the systems consisting of a number of elements which interact with one another only locally; in addition these interactions can be naturally modeled with a discrete type of computation. In this thesis, we will investigate the possibility of a cellular automata application to a problem involving continuous computations, in particular, a problem of continuous function identification from a set of examples. A fuzzy model of cellular automata is introduced and used throughout the study. Two main issues in the context of this application are addressed: representation of real values on …  Read more

The word "vecindad" in Spanish means neighborhood, but the word is also used to describe a dwelling form. The vecindad is usually known as a row of one-room dwellings surrounding an open space or patio. This kind of dwelling form exists in most Latin American countries as well as in Spain, however the word "vecindad" is used exclusively in Mexico. This dwelling form existed in Spain under the name of "corrales" and it was brought to Mexico in the XVI century with the Conquest of 1521. Initially, vecindades were built as multi-family tenements to rent to low-income artisans or workers …  Read more

Chromosome 11p15.5 harbors a gene or genes involved in Beckwith Wiedemann Syndrome (BWS) and that confer(s) susceptibility to Wilms' tumor, rhabdomyosarcoma, and hepatoblastoma. PowerBLAST of P1 artificial chromosome clones from this region identified two novel transcripts with open reading frames encoding putative proteins of 253 and 424 amino acids. The larger of the transcripts was shown by Northern blot to be predominantly expressed in the fetal and adult liver and kidney. This transcript shares homology with integral membrane organic cation transporters, such as the tetracycline resistance proteins and bacterial multidrug resistance proteins; and was therefore designated ORCTL2 (organic cation transporter-like …  Read more

I explored the relationship between neurite outgrowth and the onset of synaptic activity in the central neuropil of the leech embryo. In order to follow changes in early morphology and the onset of synaptic activity in the same identified neuron, whole cell patch clamp recordings and fluorescent dye fills were obtained from dorsal pressure-sensitive (P) cells, the first neurons that could be reliably identified in the early embryo. I followed the development of the P cell from the first extension of neurites to the elaboration of an adult-like arbour. Following the growth of primary neurites, we observed a profuse outgrowth …  Read more