McGill University Thèses et mémoires publiés en 2002

Chapter one of this thesis reviews some work on cubane, from its initial synthesis by Eaton in 1964, to the recent studies of explosive and medicinal applications. Considering the wide variety of compounds that have been synthesized, it is curious that sulfur functionalized cubane has received virtually no attention. Chapter two discusses the synthesis of cubanethiol, dicubyl disulfide, and a range of derivatives. Dicubyl disulfide possesses the shortest C-S bond length of any reported molecule where the carbon is sp3 hybridized. Calculations have confirmed that this apparently results from the high s-character that the external bonds of cubane possess. All …  Lire la suite

We designed and engineered a yeast genetic screen to isolate novel transcriptional machinery components such as elongation factors and chromatin remodelling components. When artificially recruited to a promoter, these components can stimulate gene expression. For example, fusion of known machinery components to the bacterial DNA binding domain (DBD) of LexA results in activation of test genes bearing a binding site for LexA. In a previous study, the coding region of the LexA DBD was fused to random bacterial DNA sequences and, surprisingly, 1% of all random sequences tested were able to activate transcription simply because they were negatively charged. By …  Lire la suite

Leighton, H. G. (Supervisor)  Lire la suite

These studies examined the effects of leptin administration on the regulation of hypothalamic-pituitary-adrenal axis and energy balance in neonatal rat pups. We found a significant inverse relationship between leptin and corticosterone secretion in naive pups from PND6--20. We demonstrated that chronic elevation of leptin during the first 10 days of life increased the efficiency of glucocorticoid feedback on the HPA axis following stress exposure, by increasing GR expression in the PVN and the DG. Acute leptin injection did not reduce food intake on PND5, 8 and 10, although it increased the mRNA levels of SOCS-3 and POMC, while it modulated …  Lire la suite

Meredith Monk's multi-modal work incorporates theatre, dance, film and music. Her claim is that music and specifically the voice lie at the heart of all her work. At this core, she uses auditory gesture in wordless vocal lines to express her meaning, usually the hidden narrative of emotion, to enable universal intelligibility. This thesis uses the concept of gestus in the sense of Brecht and Weill as an instrument to examine vocal gesture in three scenes in Monk's opera ATLAS, and then relates it to her compositional process. It also studies gestus in connection with Monk's biography and the influences …  Lire la suite

The objective of this thesis was to assess the acceptance of an online-questionnaire in a survey of young adults in southern Germany. The online-questionnaire was implemented in a study of respiratory diseases. Each of 280 subjects, aged 18 to 20 years, was assigned randomly to one of two groups who responded using (1) a paper-based questionnaire and (2) an otherwise identical questionnaire that was to be completed on the Internet. This group also received a copy of the printed questionnaire. Only eight subjects made use of the online-questionnaire, and the remainder of the respondents used the paper-based instrument. The major …  Lire la suite

Most Romanian national heroes lived while the Ottoman Empire dominated the Balkans. History bears witness to their doings, yet certain figures have become almost mythical thanks to the powerful impact of the nationalistic literature. Mihai Eminescu, the Romanian national poet par excellence, whose writings were merely tolerated by the Communists, exerted a strong influence despite his passionate involvement and he managed to create historical confusion lasting for generations. After 1989, Romanian history books changed. In my thesis, I seek to modify the myth of invincible Romanian heroes and to understand the reason why Romanian principalities enjoyed a special treatment during …  Lire la suite

Osteoarthritis (OA) is a degenerative, age related disease of diarthrodial joints. In OA, there is increased cleavage of type II collagen by collagenases in articular cartilage. This excessive cleavage can be caused by the altered feedback regulation of gene expression in chondrocytes by collagen type II or its degradation products which may serve as regulators of collagenase synthesis and activity through a cell surface receptor-mediated mechanism. The aim of the present study was to investigate the expression and production of collagen receptors, DDR-1 and DDR-2 in human adult normal and OA articular chondrocytes and to determine whether this correlates with …  Lire la suite

This thesis presents a method based on velocity singularities applied to the analysis of steady flows over symmetrical thickness airfoils. The method of velocity singularities has been originally developed by Mateescu for the analysis of steady flows past thin airfoils and makes use of special singularities associated to the leading edge and ridges of the airfoil to represent the complex perturbation velocity. The application of the linear method to symmetrical thickness airfoils presents inaccuracies near the leading and trailing edges of the airfoils (namely, the magnitude of the perturbation velocity in the vicinity of these points is infinite). The aim …  Lire la suite

The development of reflexive and voluntary shifts of visual attention, as well as relations between the two forms of shifting was examined in three groups of children (5-, 7-, and 9-years-old), one group of young adults (24-years-old), and two groups of senior adults (young seniors: 69-years-old, old seniors: 81-years-old). The task entailed the detection and response to the presentation of a target (black dot) in one of four possible locations in the visual field. The dependent measure was reaction time (RT). The extent to which flash cues facilitated or inhibited reflexive orienting was determined through presentation of nonpredictive abrupt onset …  Lire la suite

Gamma-frequency burst discharge in pyramidal cells of the apteronotid electrosensory lateral line lobe (ELL) is necessary for signal processing. Bursting is dependent on an interaction between somatic and apical dendritic currents, in which spike broadening in the apical dendrite potentiates a somatic afterpotential that follows each rapid somatic spike. Somatic spike repolarization must be consistent in order for the afterpotential to be expressed soon after. The work presented in this thesis describes how the expression and differential subcellular distribution of two Kv3-type K+ channels in ELL pyramidal cells may contribute to this mechanism of burst discharge. I cloned a family …  Lire la suite

Piper, David (Supervisor)  Lire la suite

This study examines institutional change in forest management in Tlalmanalco, Mexico, over the period 1877--1999 based on qualitative methods. The level of analysis is the domain of forest management, a level of analysis intermediary between macro/national policy and micro/local organizations and groups. I examine the domain composed of local organizations stakeholders in forest management in Tlalmanalco. The dual research methods include (1) a contextualist approach revealing long institutional cycles over the long run (1877--1996) while (2) grounded theory procedures reveal micro-processus of institutional change in the transition period 1996--1999. At the macro level, I have identified three institutional cycles of …  Lire la suite

Natural polymers such as polysaccharides have been used as self-assembled matrices for drug delivery. Modified high amylose starch tablets swell to a limit when submerged in water, yielding a hydrogel with quasi-reversible viscoelastic properties. Such tablets display slow-release properties with a near zero-order drug delivery kinetics. Mechanical properties, electron microscopy imaging and swelling behavior have been investigated. Results from the foregoing investigations and from 13C CP/MAS NMR studies, which showed a clear transition from amorphous to crystalline organization upon wetting, were used to propose a model. The latter proposes that the viscoelastic hydrogel is formed due to the propensity of …  Lire la suite

Social work is a profession that espouses respect for the value of diversity. However, diversity is limited in social work programs as these programs focus primarily on the teaching of verbal methods of connection for social workers to engage with clients. Non verbal methods of communication are limited in social work programs. This inhibits diversity as research has demonstrated that many clients for various reasons are unable to communicate through verbal dialogue. This present study explored social workers attitudes towards the use of art in their therapy. Six social workers from a children's mental health agency were interviewed and the …  Lire la suite

Collins, D. Louis (Supervisor)  Lire la suite

Vaginismus is a sexual dysfunction that has received insufficient empirical attention. The first chapter of this thesis consists of a critical review of the literature and demonstrates the overall paucity of research studies and their poor methodological quality. The second and third chapter are based on the results of an experimental study comparing 87 women, matched on age, relationship status, and parity and assigned to 3 groups, vaginismus, dyspareunia/vulvar vestibulitis syndrome (VVS), and no pain. A structured interview evaluating pain with intercourse and history of gynecological problems as well as psychometric measures; evaluating sexual and physical abuse, sexual knowledge and …  Lire la suite

Huang, Jiefang (Supervisor)  Lire la suite

The doctoral thesis investigates the impact of legal mobilization and judicial decisions on official minority-language education (OMLE) policy outside Quebec using a model of judicial impact derived from New Institutionalism theory. The New Institutionalism (NI) model of judicial impact synthesizes the dominant approaches to judicial impact found in the US literature, which are reviewed in Chapter Two, and transcends them by placing them within a framework based on the New Institutionalism. The model, as developed in Chapter Three, proposes that certain factors will increase the probability of judicial decisions having a positive influence on policy, such as whether incentives are …  Lire la suite

Precup, Doina (Supervisor)  Lire la suite

Oligomerization of membrane proteins in response to external stimulation is a common event in cell signalling for generating functional diversity. In the case of the heptahelical receptor (HHR) superfamily, the traditional view has been that these receptors function as monomers, although a number of recent studies have suggested that this class of membrane proteins may exist as dimers or higher order oligomers, and play an important role in signalling. We addressed this question using as a model the somatostatin receptor (SSTR) family, which comprises five molecular subtypes (SSTR1--5). Receptors were expressed at physiological levels in CHO-K1 cells and characterized pharmacologically …  Lire la suite

This study tests the ability of the Canadian Land Surface Scheme (CLASS) to simulate sensible and latent heat fluxes over two subarctic tundra sites in the Trail Valley Creek (TVC) drainage basin, North West Territories, Canada. CLASS simulations with and without the new organic soil parameterisation developed for peatland conditions were compared with three summer months of measurements at each site. The sites are located in a cryoturbated region and are underlain by continuous permafrost and feature mineral soil hummocks and organic soil inter-hummock zones. Results from the peatland version of CLASS showed significant improvement over the standard version although …  Lire la suite

This work focused on the natural development of neurotachykinin-1 (NK-1) receptors in the porcine brainstem during postnatal development (using 4 ages vs adult), and on alterations in these receptors after single and six-daily repeated clustered hypoxia (using young and older piglets). NK-1 receptor localization and densities were determined by quantitative autoradiography, using mono-iodinated Bolton-Hunter substance P ([125I]-BHSP). Slide-mounted brainstem sections, incubated in [125I]-BHSP and then exposed to film, have shown [125I]-BHSP binding throughout many brainstem nuclei and tracts, including the ambigual/periambigual (nAmb), dorsal motor vagal (dmnv), hypoglossal (nHyp), lateral reticular (nRL), gigantocellular (nGC), solitary tract (nTS), medial parabrachial (nPBM), and …  Lire la suite

Paradis, Gilles (Supervisor)  Lire la suite

Navigation by satellite---GNSS---is a local technology with global repercussions. Although operation and control rest in government hands, the consequences of satellite use, most often beneficial, have a worldwide effect. Controversy arises when this free-of-direct-charge technology, on which the International Community relies, fails, thus causing damage to third parties. It was the intention of the drafters and negotiators of the international space law regime to establish a victim-oriented liability framework, in order to guarantee adequate compensation for damage caused by space activities. Unfortunately, it seems that the present regime has only partially met these goals. The surest means of obtaining compensation …  Lire la suite

Bulat Shalvovich Okudzhava, the originator of the style of Russian bards, was the first to express his nation's disillusionment over the country's political system and government in a new and alternative way. For this purpose, he used the direct impact of his poetry, a part of which he would sing for audiences, accompanied only by his guitar. This sort of communication between the writer and his interlocutors remained in sharp contrast with the means traditionally used by the official Soviet mass culture. The spreading of guitar poetry was impossible to control by authorities, since for popularization it used not only …  Lire la suite

DNA-binding proteins such as IHF play a crucial role in bacterial survival. IHF is involved in many biological processes in E. coli and possibly in other bacteria. It was hypothesized that another protein, Nlp, belongs to a family of conserved DNA-binding proteins, and this protein was shown to be non-essential for cell viability, but highly conserved among the Enterobacteriaceae. As Nlp appears to play a role in gene regulation, we wished to identify all Nlp-regulated genes. nlp was cloned into pBAD18-Kan generating pMM5, where Nlp expression was under the control of arabinose. Strain LF20300 was transformed with pMM5 and then …  Lire la suite

The goal of this thesis was to examine submerged macrophoe biomass, distribution, and ecosystem effects at scales large enough to incorporate the littoral zone into models of whole lake structure and function. Submerged macrophyte biomass and distribution was shown to be highly variable between growing seasons and primarily dependant upon air temperature and the timing of the onset of the growing season. Within a growing season, a mass balance study showed an undisturbed macrophyte bed to markedly lower phytoplankton biomass: total phosphorus ratios, although the net effect of the bed on the growing season phosphorus budget was minimal. The weedbed …  Lire la suite

The relationship between precipitation and atmospheric vertical motion is investigated over the globe. By combining and averaging precipitation rates within small ranges of vertical motion, the mean precipitation rate is found to vary smoothly with vertical motion. The relationship is modelled with a simple function that assumes zero precipitation for subsidence and linearly increasing precipitation for ascending motion. Function parameters are computed from NCEP reanalysis data individually for every grid point and every calendar month. Variations in the slope account for geographical and seasonal variations in moisture and other precipitation factors. At each grid point, the scheme diagnoses precipitation rate …  Lire la suite

Differing opinions among the disciplines involved in the diagnosis and treatment of children with attention-deficit/hyperactivity disorder (ADHD) have left parents navigating in a maze of divergent languages, explanations, and treatment recommendations. This quantitative research study addressed the question of whether a parent training program was an effective treatment for families of children with ADHD residing in a rural community. Although this community-based study did not demonstrate statistically significant outcome measures, it did reveal some interesting side effects. The limitations and the clinical significance of the findings of the study are examined for future research purposes. In particular, the implications for …  Lire la suite

A continuing challenge in occupational hygiene is that of estimating exposure to the multitude of airborne chemicals found in the workplace and surrounding community. Occupational exposure limits (OELs) have been established to prescribe the acceptable time weighted average for many different chemicals. Comparing the OELs to the measured workplace concentration allows occupational hygienists to assess the health risks and the need for control measures. Hence, methods to more effectively sample contaminants in the workplace are necessary to ensure that accurate exposure characterizations are completed. Evacuated canisters have been used for many years to collect ambient air samples for gases and …  Lire la suite

In response to stresses such as the accumulation of misfolded proteins, the Endoplasmic Reticulum (ER) triggers cytosolic and nuclear signalling events, which are integrated by the cell to result in adaptation or apoptosis. The activation of stress-responsive kinases (SAPKs) and the mitogen-activated kinases (MAPKs) are known to have a key influence cell fate determination. We developed a technique to study the regulation of these kinases by the ER in response to drugs inducing protein misfolding. We isolated ER like compartments with a relatively high degree of purity using magnetic beads coated with anti-calnexin antibodies and vie reconstituted in a cell …  Lire la suite

A phase-field approach describing the formation and evolution of an hexagonally patterned surface is presented. We studied a free-energy and a time-dependent Ginzburg-Landau equation for which the order parameter is non-conserved. We give a review of the scaling phenomena in general and of hexagonal systems in particular, both from theoretical and experimental points of views. A squared shaped grid of varied sizes, with periodical boundary conditions, was used for the simulations. First, we studied the evolution of surfaces themselves. Then, we considered the evolution of the structure factor's maximum amplitude, and full width at half maximum. Scaling laws as a …  Lire la suite

Barker, Philip (Supervisor)  Lire la suite

"Il est généralement considéré que les organes sensoriels et les noyaux vestibulaires encodent la vitesse angulaire de notre tête. Hors, en plus de recevoir des projections directes des nerfs vestibulaires, les noyaux vestibulaires recoivent des projections du cortex, du cervelet, ainsi que d'autres structures du tronc cérébral. Étant donné cette variété, nous avons posé la question: comment, lors de comportements naturels, les réponses de neurones dans les noyaux vestibulaires sont-elles modifiées par ces projections? Nos recherches ont porté sur trois types de neurones: 1) les neurones purement vestibulaires (VO) qui génèrent le réflexe vestibulocollique (VCR); 2) les neurones position vestibulaire …  Lire la suite

The goal of the present study was to measure the reactivity of the salivary cortisol in depressed patients and controls exposed to emotional and neutral memory tasks. We recruited 21 depressed patients, 9 in an active phase of depression, 12 in remission and 17 controls. The 3 groups were similar. The protocol consisted of a task to assess explicit memory in two separate conditions: neutral and emotional words to learn consciously on two separate days. During both assessments, we took salivary samples each 10 minutes to assess the concentration of free cortisol before, during and after the memory task. A …  Lire la suite

This dissertation is an analysis of writings and illustrative material by Canadian travel writers Anna Jameson, Mina Hubbard, and Margaret Laurence, that attempts to reconcile the masculinist focus of postcolonial criticism and the charges of cultural imperialism levied against feminist criticism with the role postcolonial and feminist theories play in understanding women's travel narratives. I argue that Jameson's 1838 Winter Studies and Summer Rambles in Canada, Hubbard's 1908 A Woman's Way through Unknown Labrador, and Laurence's 1963 The Prophet's Camel Bell provide maps of the political, cultural, and physical features of the areas through which the women travelled, and of …  Lire la suite

van de Voort, F. R. (Supervisor)  Lire la suite

Individuals with autism experience specific deficits in the area of executive function. A differentiated view of executive function was recently described by Metcalfe and Mishel, in which a distinction was made between hot, affective components and cold more purely cognitive, non-affective components. The "Hot/Cold" distinction of executive function was examined in a group of children with autism in relation to a group of typically developing children matched on verbal, pattern and Leiter mental ages. Two hot (Gamble and Delay of Gratification) and two cold tasks (DCCS and SOP) were administered. Children with autism successfully completed fewer trials of the SOP, …  Lire la suite

The following qualitative study explored self-reported iatrogenic effects of intervention with data collected through semi-structured interviews. This small clinical sample consisted of four female adult "survivors" between the age of 34 and 47 who had experienced childhood sexual abuse perpetrated by at least one caregiver. The findings indicated significant iatrogenic effects particularly for the victims who disclosed in childhood that included a strong theme of betrayal by the systems that were supposed to protect them. One woman continued to be sexually abused, while another woman was returned to the home where she had been physically abused, following no intervention and/or …  Lire la suite

Harpp, D. N. (Supervisor)  Lire la suite

Wood Poles are extensively used in North America as supports for electric distribution lines. On average, wood poles have a service life of 40 years with a replacement cost of approximately $2000. Since the distribution network is of relatively recent construction, maintenance and replacement costs have been relatively small compared to the total number of poles in service. The goal of this thesis is to use the FORM/SORM algorithm to evaluate the reliability of a single pole and the results obtained when applied to a sample of 887 wood poles inspected in the field. The procedure was also applied to …  Lire la suite

The behavior of the shear layers separating from a rotationally oscillating cylinder was investigated using hot-wire anemometry and smoke-flow visualization in a wind tunnel at a Reynolds number of 3700. The cylinder was oscillated at small peak-to-peak amplitudes and frequencies lower than and near the natural Kannan frequency. The shear layers responded in a way such that their characteristics were modified depending on the frequency and amplitude of oscillation. Results showed that as the oscillation frequency increased, the shear layers were highly disturbed, the shear-layer instability was promoted upstream and its frequency increased, the shear-layer vortices formed antisymmetrically and closer …  Lire la suite

X-linked hypophosphatemia (XLH), the most prevalent form of inherited rickets in humans, is caused by mutations in the PHEX gene, which encodes a protein with high homology to the M13 family of type-II integral membrane zinc metallopeptidases. We created an online mutation database, PHEXdb (http://data.mch.mcgill.ca/phexdb), to catalogue PHEX mutations identified in XLH patients, and found that missense mutations account for 22% of the 157 mutations reported to date. We also undertook to examine the effects of eight missense mutations (C85R, D237G, Y317F, G579R, G579V, S711R, A720T, and F731Y) on synthesis, glycosylation, cellular trafficking, and catalytic activity of the recombinant proteins …  Lire la suite

Sekaly, Rafick-Pierre (Supervisor)  Lire la suite

In light of its past eugenic use, and its often irreversible nature, non-therapeutic sterilization, the result of which is to deprive an individual of his/her capacity to procreate, has always enjoyed a particular status and its use and legal status engendered debate, discussion and controversy. The purpose of this dissertation is to determine under which conditions non-therapeutic sterilization can lawfully be performed under Canadian law. Whereas the legality of non-therapeutic sterilization when voluntarily consented to by a competent individual is today established in all Canadian provinces, it appears that Quebec is the only province to allow non-therapeutic sterilization to be …  Lire la suite

With the conservative estimates of Internet usage doubling each year, the need for bandwidth at the core of the Internet is outpacing the ability of conventional router technology to keep up. A routing system that can scale to keep pace with Internet traffic growth is currently being developed. This thesis proposes the use of a VCSEL-based parallel optical interconnect system to achieve the high-speed, multi-channel, chassis-to-chassis interconnection requirements. With 1 x 12 VCSEL and PIN arrays operating at 2.5 Gb/s per channel, a large aggregate bandwidth of 30 Gb/s can be interconnected in a very small footprint. In order to …  Lire la suite

Binaural comparison of intensity is the basis of sound localisation in crickets. Two features of the neural response, response strength and response latency, can encode intensity. Therefore, binaural difference in spike-count and in latency can be used as sound localisation cues. In this work, I investigate the effects of ultrasound intensity and pulse-rate on sound localisation cues as well as the directionality of the response in an ultrasound-sensitive interneuron, AN2. I found that habituation, a decline in neural response, decreases binaural cues encoded in spike-count but increases the cues encoded in first-spike latency. In addition, binaural spike-count and latency difference …  Lire la suite

Mujumdar, A. S. (Supervisor)  Lire la suite

The Wallace Lake greenstone belt is located on the southern margin of the Uchi-Sachigo-Goudalie superterrane within the volcanic-rich Uchi subprovince of the Superior Province in southeastern Manitoba, Canada. Its stratigraphy consists of a Mesoarchean complex constituted of alluvial conglomerate derived from ca. 3000 Ma tonalite, overlain by a crustal contaminated mafic-ultramafic volcanic sequence. Both units were deformed and then intruded by a 2.92 Ga tonalite body and related dyke swarm. Thrust sheets of a tholeftic volcanic sequence of unknown age, of oceanic plateau affinity tectonically overlie this Mesoarchean complex. The tectonic assembly was associated with regional SW directed compression, resulting …  Lire la suite