McGill University Thèses et mémoires publiés en 1998

As digital electronics becomes increasingly popular, the need for efficient data conversion to provide the link to our analog world grows all the more important. To sustain the current rate of technological advancement, the requirements on the data conversion systems are becoming more stringent. Wireless communication systems demand high speed, high performance analog-to-digital conversion front-ends. Furthermore, consumers demand quality electronics at low cost, which precludes the use of expensive analog processes. This thesis investigates the potential of DeltaSigma modulation techniques in addressing both of these issues through the design, implementation and experimentation of several prototype integrated circuits. Delta-Sigma modulation has …  Lire la suite

Cyclooxygenase and lipoxygenase enzymes metabolize arachidonic acid to biologically active eicosanoids which act as potent local mediators of various physiological and pathological responses. The production of certain immunoregulatory eicosanoids may help parasites to evade host immune responses and establish chronic infections. Our analysis of arachidonic acid metabolites synthesized by the adult trematode parasite Schistosoma mansoni indicated the presence of a soluble, enzymatically active lipoxygenase (LOX) and the absence of any cyclooxygenase (COX) activity. Screening of several S. mansoni cDNA libraries using mammalian LOX sequences resulted in the cloning of the mouse (the parasite host) LOX homologue due to the high …  Lire la suite

This historical and conceptual thesis examines the cultural and socio-economic situatedness of education and development in the different epochs of South African history from the arrival of the first European settlers in 1652 up to the present post-apartheid era. The project assumes that cultural domination is utilized for the creation and long-term maintenance of systems of learning that are embedded in colonial and exploitative relationships. These relationships are generally defined by the socio-economic development of the dominant group at the expense of subordinated populations. Moreover, the thesis argues that colonial, and specifically apartheid education in the South African situation were …  Lire la suite

Modification of the eutectic silicon in Al-Si alloys is traditionally performed by sodium and strontium addition. Although not traditionally used as a modifier, calcium also has the potential to modify the eutectic silicon in Al-Si alloys. Metallographic observation and thermal analysis studies in A357 alloy indicate that. when the cooling rate is quite low. Ca modifies the eutectic silicon. but the effect of Ca as a modifier is not as strong as is Na or Sr. When the cooling rate is high, a fully modified structure can be obtained with calcium. Recovery of Ca in the melt is high and …  Lire la suite

In vitro culture techniques are widely used in potato for rapid production of specific pathogen tested plantlets and microtubers, which are essential for seed certification programs. The limited calcium (Ca) uptake in vitro promotes physiological disorders in many micropropagated species including potato. Factors that may affect Ca uptake by potato plantlets, including cations, osmotic potential, and boron (B) were examined. The possibility of improving microtuber yield by low pH shock or successive harvests, which stimulated greenhouse potato production, were also investigated. Ca uptake by cvs. Norland and Bintje potato plantlets grown on modified Murashige and Skoog (MS, 1962) media was …  Lire la suite

Gunjal, Kisan (Supervisor)  Lire la suite

This formation of new business arrangements, in the form of strategic alliances, is the topic upon which this thesis is focused. Two new types of business agreements, which have been observed, are strategic contract-based alliances and strategic fuzzy alliances. While, contract-based alliances are new, in that firms are choosing non-traditional partners, strategic fuzzy alliances are quite unique as they involve trust. The aim of this thesis is to analyse these alliances and the role of trust in business-to-business relationships. This will be accomplished in two ways. First, using Shapiro et al.'s (1992) taxonomy of trust and a neo-classical framework, a …  Lire la suite

An emerging phenomenon, which anticipates deregulation, liberalization of trade, and changes in competition law, is the increasing interaction among telecommunications carriers resulting in the formation of global alliances. These global alliances---on a larger scale---also involve broadcasting and computing companies that have been regulated in a totally different fashion. A likely consequence of this sweeping technological revolution is that telecommunications will gradually integrate and converge with these segments of the communications industry. As part of this all-service-convergence trend, a number of key international telecommunications alliances (henceforth ITAs) are scrutinized. The thesis begins by canvassing leading business-organization theories that attempt to account …  Lire la suite

Munz, R. J. (Supervisor)  Lire la suite

The global telecommunications environment is undergoing rapid and radical transformation. Liberalisation in the industrialised economies, prompted by the fast pact of innovation in telecommunications technology has spilled over to developing countries, which now realise the significance of telecommunications for socio-economic development within their economies. The most significant aspect of these developments is that it has led to the liberalisation of telecommunications companies and the opening up of market access under the auspices of the World Trade Organisation. There is now open competition in a glob al telecommunications industry. Multinational companies equipped with the state-of-the-art technologies, ample experience and service skills, …  Lire la suite

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

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

The main objectives of this prospective cohort study were to examine the construct and predictive validity of the STREAM, and estimating its responsiveness. Sixty three acute stroke patients were evaluated on the STREAM and other measures of impairment and disability during the first week post-stroke, four weeks later, and three months post-stroke. The results of the study showed that STREAM scores were associated with measures of impairment and disability, and could discriminate subjects based on Balance Scale and Barthel Index scores. Moreover, the STREAM during the first week post-stroke was found to be an independent predictor of discharge destination after …  Lire la suite

Solid-state and solution NMR technique, were used in order to study the transformation of various functional groups present in lignin and cellulose when wood is exposed to a wide range of pH's and pulping reagents. Solid-state proton spin-lattice relaxation times (T1H) allowed the determination of the molecular mobilities of carbohydrates and lignin as a function of PH for black spruce softwood. Similar measurements on isolated cellulose and cuoxam lignin were also conducted. These studies showed that the mobilities of the polymeric constituents of wood are affected by ionization processes occurring on the various functional groups present in lignin and cellulose. …  Lire la suite

In this dissertation we study compression and robust transmission of images over wireless channels. Due to the problems associated with wireless channels, image communication over these channels requires error-resilient coding schemes that must offer good compression and low complexity. We propose an analysis-by-synthesis coding technique called Variable Block-size two-dimensional Code Excited Linear Predictive (VB 2D-CELP) coding that implements block-adaptive prediction and variable block-size coding. The method can be used for still picture coding or for periodic intra-frame coding required in time-varying image coding. The scheme demonstrates its merits over the DCT-based JPEG standard by reducing the block effects of the …  Lire la suite

The response of in vitro-grown Solanum tuberosum L., cvs. Russet Burbank (RB) (salt-sensitive) and Sierra (S) (salt-tolerant) potatoes was investigated when [NaCl] was increased from 0 to 80 mM in the presence of 6, 20, and 30 mM [K] in a Murashige and Skoog (MS) basal medium. The tested growth parameters, Mg and Ca content, and K+/Na + ratios in the laminae and the roots were negatively affected as [NaCl] increased. The salt stress was relatively severe on growth of RB plants whereas the salt-tolerant (S) variety was affected to a lesser extent. There were indications that Na in the …  Lire la suite

Photovoltaic cells having the structures CuInSe2-CdO and CuInSe 2-CdS-CdO have been fabricated on a cut or cleaved p-type Bridgman-grown CuInSe2 ingot. The CdO window layer in both cases was deposited by dc reactive sputtering. In the CuInSe2-CdS-CdO structures, the CdS interlayer was deposited by a solution growth method and these cells, incorporating the CdS interlayer, yielded a conversion efficiency of about 6.9%. By comparison, the cell with the structure CuInSe2-CdO, where the lattice mismatch between the CuInSe2 and the CdO is some 23%, showed a surprising efficiency of 6.8%. This result, indicating that the defect centers at the CuInSe2-CdO interface …  Lire la suite

La préconcentration d'échantillons liquides et l'analyse de métaux au niveau de traces dans une matrice minérale très stable a été réalisée en utilisant des fours à graphite (FG) accouplés à un plasma à couplage inductif. Plusieurs éléments réfractaires ont été évalués directement dans une matrice de zéolite en utilisant un four au graphite modifié de façon à permettre l'emploi d'un melange gazeux argon/fréon. L'échantillon de zéolite a été déposé dans le tube de graphite sous forme de suspension et une digestion complète de la matrice minérale a été obtenué par formation d'halogénures.[...]  Lire la suite

Le bassin versant Fayoum en Egypte est un bassin fermé n'ayant aucun drainage naturel. Des eaux de drainage salées sont evacuees et entreposées dans le lac Qaroun, où elles deviennent sujet a la concentration par evaporation. Suite a ces contraintes physiques et environnementales, la gestion d'eau et de sel y est généralement difficile. L'accumulation de sels dans le lac peut atteindre des niveaux dangeureux. Afin d'évaluer différentes alternatives de gestion eau / sel, des modèles mathématiques portant sur l'évaporation lacustre, l'acheminement des eaux, et l'équilibre en eau du bassin versant, furent développés et mis a l'épreuve. Les résultats des modèles …  Lire la suite

The Fayoum basin of Egypt is a closed basin with a lack of natural drainage outlets. The saline drainage water disposed of and impounded into Lake Qaroun is subject to evapoconcentration. As a result of these physical and environmental constraints, water and salt management are generally hampered, and salt accumulation in the lake can reach hazardous levels. In order to assess alternative water and salt managment scenarios, mathematical models of lake evaporation, as well as lake routing and basin water balance were developed and tested.[...]  Lire la suite

A climatology of high wind events (HWEs) affecting Sable Island (44°N, 60°W) and Halifax (44.5°N, 63.5°W) was constructed for the period 1979--1995. We then focussed on HWEs at Sable Island in more detail because of their high frequency relative to Halifax. Events were stratified into four groups based on the direction of the peak speed: NE (1°--90°), SE (91°--180°), SW (181°--270°), and NW (271°--360°). Synoptic structures and statistically significant atmospheric anomalies were identified in composites for each group. More detailed structures were found in composites constructed with the aid of a cluster analysis. NW HWEs were associated with rapidly deepening …  Lire la suite

Locker, David  Lire la suite

Martin Amis remains on the outer fringes of the modern literary canon because his novels have not been appreciated in the context within which they were written. This is, basically, a postmodernist experimental mode which self-consciously tests (but does not abandon) the boundaries of form and content in the traditional English novel. The principal contention here is that Amis "challenges" but does not "change" the human subject as it exists in literature. Hyper-self-consciousness, the signature mark of postmodernism, does not mean simply that Amis's characters are just one-dimensional pawns of literary gamesmanship, even though this is a valid point of …  Lire la suite

The European Community, today European Union, has been considered as a model to measure the success or failure of other Regional Integration Arrangements (RIAs). Harmonization can be understood as the promotion of convergence within different legal systems. Particularly in this case, harmonization of Member States' legislation has been a central legislative tool in establishing the internal market. However, harmonization, in areas such as technical standards and professional services, is not pursued as a main goal by all RIAs. This is because not all RIAs pursue the same degree of economic integration. However, due to the fact that differences in national …  Lire la suite

En juin 1940, se résignant Ii la défaite de la France et prêt à collaborer avec le Troisième Reich, le maréchal Pétain prend la direction d'un régime autoritaire, catholique et corporatiste: le gouvernement de Vichy. Mais à Londres, les Français libres, diriges par le général de Gaulle, refusent de s'avouer vaincus et contestent la légitimité du régime de Vichy. La France libre et la France de Vichy s'engagent alors dans un combat pour l'opinion Français. Au milieu de la tourmente, l'affrontement déborde les frontières nationales, les deux partis luttant pour la reconnaissance internationale. Le Canada Français - pour des raisons …  Lire la suite

If one painstakingly analyzes and compares the novel, the theatrical and the libretto versions of Marguerite-Violetta, a several-time reborn character from the novel and drama Camille, one notices striking differences and gleans useful insights as to the peculiarity of the three genres involved (novel, theatre and opera) and as to the reductive work of the libretto writer who, by modifying the roles of the characters and the values they channel, achieves a synthesis that has no match in the works he draws from. This thesis aimed precisely at highlighting the intervening differences among the three genres, while pointing out the …  Lire la suite

The thesis traces the concepts of such crimes under international law as genocide and crimes against humanity, of individual and collective responsibility for these crimes, and identifies the place of crimes of former communist regimes in Central and Eastern Europe among them. The thesis examines the sources of a duty to investigate and to punish human rights violations of a prior regime in international treaty and customary law which is not affected by a succession of States. An analysis of different methods by which post-communist democracies of Central and Eastern Europe come to terms with their past gives evidence of …  Lire la suite

Ibn Sina has been the object of many contemporary studies, all of which have attempted to examine various angles of the possible connection between Ibn Sina and mysticism. These studies, however, have not fully explored Ibn Sina's understanding of mysticism; he is generally seen as the most rational philosopher who ever lived and, therefore, unlikely to have been a mystic in any sense. In response to this claim, the present study aims to reconsider Ibn Sina's connection with mysticism and to examine his own perception of this tradition. This thesis first looks at the various factors which may possibly have …  Lire la suite

The purpose of this study was to determine the timing and extent of gains in strength, mobility, balance and functional status that follow a high-intensity strengthening program offered to two groups of institutionalized elderly subjects. Thirty two subjects were randomly selected and classified as a person with a HIGH or LOW mobility based on the timed "Up and Go" (TUG) score (<20 sec or ≥20 sec respectively). The hypothesis was that the exercise regimen would have a greater impact on the LOW mobility group as compared to the HIGH mobility group. Dynamic strength, mobility, balance and functional level were evaluated …  Lire la suite

This thesis reports work not only on the numerics behind, but also the implementation of real-time redundancy-resolution schemes on a real robot. Furthermore, the robot that was chosen as the experimental platform is, isotropic. Redundant robots have more degrees of freedom than needed to perform a class of tasks. A new performance index is proposed in the thesis, that is quadratic in the joint variables and its weighting function has units of frequency. It is shown how this performance index can produce cyclic trajectories in a simple manner, thereby eliminating the undesired drift of the joint angles upon tracking a …  Lire la suite

A thermodynamic-dynamic sea ice model based on the granular material rheology of Tremblay and Mysak is used to study the interannual variability of the Arctic sea ice cover during the 41-year period 1958--1998. The sea ice model is coupled to both a mixed layer ocean model and a one-layer thermodynamic atmospheric model. The model is first run with monthly climatology for most of the thermodynamic and dynamic forcing components to obtain a stable periodic seasonal cycle. For the 41-year run, the monthly wind stress forcing is derived from analyzed sea level pressures from the National Centers for Environmental Prediction (NCEP …  Lire la suite

The goal of this study was to further understanding of the ecology and propagation of an important wild food resource (Vatovaea pseudolablab (Harms.) Gillett of the community of Loodokilani, Kajiado District Kenya and by extension, contribute to its sustainable use. Vatovaea pseudolablab is found in occasional, yet distinct patches in Lookidalani and these patches may be associated with a particular soil-water regime. The associated soils are moderately developed, dark brown (7.5YR 3/2, Munsell) clayloams, with small (5.61 mm), angular blocky aggregates. The patches were moderately covered (30%) with medium-sized stones (9.5 cm). Woody and leafy cuttings from wild stock were …  Lire la suite

This exploratory study identified 18 factors influencing the choice of an educational-travel program and refined a typology of the older adult educational-travel participant. A mail questionnaire queried 963 Canadian and American participants, aged 45 to 92 years, who had enrolled in a fall 1997 Elderhostel Canada program, but not yet attended. The number of useable surveys was 811, representing an 84.2% rate of return. The analysis employed descriptive statistics, correlation, factor analysis, step-wise regression analysis, analysis of variance, and content analysis. Five participant types were identified in this study: the Explorer, Activity-Oriented, Content-Committed, Convenience-Oriented, and Opportunist. Sixty-three percent of the …  Lire la suite

Although the single-path changepoint problem has been extensively treated in the statistical literature, the multi-path changepoint problem has been largely ignored. In the multi-path changepoint setting it is often of interest to assess the impact of covariates on the changepoint itself as well as on the parameters before and after the changepoint. This thesis is concerned with including covariates in the changepoint distribution, a topic never before addressed in the literature. The model we introduce, based on the hazard of change, enjoys features which allow one to establish asymptotic results needed for estimation and testing. Indeed, we establish consistency of …  Lire la suite

The E1B-55 kDa protein of human adenovirus type 5 is known to function early in lytic infection by reversing growth arrest and apoptosis that result from E1A-induced accumulation and activation of the p53 cellular tumor suppressor. This function allows infected cells to survive long enough to produce high levels of progeny virions, and in the case of rodent cells it permits the formation of stable E1A transformants. The E1B-55 kDa protein binds to p53 and inhibits its ability to activate transcription. Inhibition of p53 appears to result from transcriptional repression activity associated with the E1B-55 kDa polypeptide. In the present …  Lire la suite

As environmental issues and the communities that confront them increasingly transcend borders, environmentalists in the North (wealthier countries) and the South (poorer countries) face the challenges of effective communication and collaboration. Acknowledging differences in how environmentalists culturally construct the environment is an important starting point; particularly given the tendency on the part of Northern environmentalists to assume (a) that environmentalism is essentially the same in different cultures i.e., it is all like Northern environmentalism; and (b) that environmentalism is more developed in the North. This study examines and compares the constructed environments of a sample of Mexican and Canadian environmentalists. …  Lire la suite

L'expression des trois protéines de neurofilaments (NF) NFL, NFM et NFH ainsi que I'a-intemexine et la périphérine a été déterminée par immunobuvardage "Western" durant Ie développement de neurones embryonnaires de ganglions dorsaux en culture. Au jour 0 de la culture, les neurones contenaient surtout de I'a-intemexine. La quantité de périphérine a augmenté de façon significative après 1-2 jours en culture, celle de NFL et NFM après 2-3 jours, et celle de NFH après 5-6 jours. L'analyse des cultures par immunofluorescence indirecte a révélé que les cinq protéines de filament intermédiaire neuronaux (Fin) étaient co-Iocalisées dans tout les compartiments des neurones. …  Lire la suite

Although the physiological nitrogen demand of the soil microbial biomass is a major determinant of N mineralization in forest soils, the exact nature of the relationship is unclear. This study investigated the relationships between a respiration-based indicator of microbial physiological N demand (NIR) and N availability in forest soils. NIR was found to correlate significantly with net mineralized N in the field and annual foliar litterfall N fluxes. In a laboratory incubation, NIR was shown to be sensitive to changes in soil available C and N pools. These results demonstrated that microbial physiological N demand is determined by relative availabilities …  Lire la suite

There have been many cases of intrusion of civil aircraft into the airspace of foreign States. On occasion, the subjacent State has reacted by using force against such aircraft, sometimes with fatal consequences. Customary international law admits the use of force only in exceptional circumstances. As the United Nations specialized agency responsible for international civil aviation, ICAO has conducted fact-finding investigations into a number of cases of aerial shootdowns and adopted resolutions and taken decisions in this connection. Such resolutions and decisions have clearly been influenced by political factors. The Organization has also taken specific legal and technical steps aimed …  Lire la suite

This study examined whether children's cognitive perceptions of the amount of skill and luck involved in gambling activities could be modified as a function of reinforcement schedules on a gambling task (Hilo). Children (N = 174) from grades 5 and 7 completed a questionnaire to evaluate cognitions and played a computer simulated card-cutting game. Cognitions were assessed after the game to examine if cognitive perceptions changed and then again one and four weeks later to evaluate if changes were maintained. Results reveal that experiencing repeated losses decreased perceived skill and increased perceptions of luck on gambling tasks in general. Cognitive …  Lire la suite

Transformed fatigue resistant skeletal muscle has been proposed as a potential power source for totally implantable ventricular assist systems (VAS). The goal of this study was to determine the optimal latissimus dorsi muscle (LDM) configuration capable of obtaining maximum power output. A device was designed to measure the power output and performance characteristics at varying levels of preload from each of four in situ configurations in Watts/kg of muscle(W/kg). Eight LDMs were acutely measured and revealed peak power output as follows: Sub-Dorsi (compliance chamber between LDM and chest wall): 8.3 +/- 1.6 W/kg; Circular (chamber in skeletal muscle ventricle): 16.4 …  Lire la suite

This thesis examines the potential of using virtual reality (VR) to implement virtual environments for training in suitable tasks, and demonstrates that this potential can be fulfilled. The Virtual Reality Welding Intelligent Tutoring System VR-WITS incorporates advanced features such as 3D video display, sophisticated navigation and object manipulation interfaces, human representation and an expert system to validate operations. All these human-computer interaction techniques are brought together, they offer the opportunity of learning with a virtual training environment rather than the usual classroom-like experience. VR-WITS is a VR-based "learn-by-doing" system developed for the training of maintenance workers in performing grounding welds …  Lire la suite

This thesis documents the design and implementation of computations, the procedural abstraction facility of a database programming language. Conceived as a special form of relation, computations fit neatly into the relational model. A computation is defined over a set of domains, which also act as parameters. Invocation is accomplished by means of the operators of the relational algebra. A computation is intended to embody a constraint amongst its parameters. These are grouped into inputs and outputs at call time. Given a set of input values, the computation returns output values that satisfy the constraint. Computations may be recursive, and may …  Lire la suite

Today, many companies are interested in improving their competitive position in the marketplace, and hence, compete by bringing new products and value added services to the market in a timely fashion, at low cost and enhanced quality. Concurrent Engineering (CE), a new methodology and a systematic approach to the integrated design of products and related processes including manufacture and support is ideal, for this environment. Organizations implement CE to achieve specific goals. This thesis focuses on the goals of time, cost and quality for implementing CE. The existence of specific models or methods of implementation of CE for specific goals …  Lire la suite

This thesis focuses on the effects of temporary block of glycolysis by the competitive antimetabolite 2-deoxy-D-glucose (2-DG) on neuronal activity in the CA1 region of rat hippocampal slices. The overall aim was to investigate how synaptic transmission is suppressed when metabolism is greatly reduced by the replacement of glucose by 2-DG to provide some insight into the cellular mechanisms underlying these depressant effects. Experiments were carried out on hippocampal slices kept submerged and constantly superfused with oxygenated saline at 33--34°C. Block of glycolysis was induced by replacement of glucose by equimolar concentrations of 2-DG. Changes in synaptic efficacy and postsynaptic …  Lire la suite

Suissa, Samy (Supervisor)  Lire la suite

The signal transduction pathways that mediate metabolic and mitogenic effects in primary rat hepatocytes were investigated. Transcriptional inhibition by insulin of the metabolic gene insulin-like growth factor binding protein-1 (IGFBP-1) was P13-kinase-dependent and sensitive to rapamycin, an Inhibitor of p7Os6k activation at the level of mTOR. In hepatocytes, P13-kinase contributes to p70s6k activation. Our results described the first example of an insulin-specific gene, whose regulation is both P13-kinase- and p70s6k-dependent. MAP kinases were not Involved in regulating this nuclear event. DNA synthesis by insulin was not effected by to MAP kinase signalling pathway, but was p13-kinase-dependent and sensitive to rapamycin. …  Lire la suite

This thesis delineates the context and history of the field of cultural studies, specifically tracing the construction of culture as a site of critical theory. Primarily, it explores the influence of Marxist philosophies in politicizing the culture concept, and subsequently surveys the set of internal debates in progressive theory. Comparing the various strengths and limitations of political economy, American cultural consumption discourse, and British cultural materialism, ultimately the thesis argues in favour of instating the third paradigm as the privileged analytical model of progressive scholarship. Cultural materialism is cited for its methodological excellence and political relevance in the contemporary world.  Lire la suite

Neurogenic claudication is often seen in patients with lumbar spinal stenosis. The pathogenesis of neurogenic claudication is thought to be due to relative ischemia of cauda equina roots during exercise. We studied the effect of transient ischemia brought on by exercise on motor conduction in patients suffering from lumbar spinal stenosis. We found that there is a statistically significant difference in the motor evoked potential latency time and in the peripheral motor conduction time measured before and after exercise in the patients with signs of neurological deficit (Hest p<O.0001). This difference was not found to be statistically significant in patients …  Lire la suite

Wilms' tumor, a childhood malignancy of the kidney, is one of the most common pediatric tumors. The disease occurs in both sporadic and hereditary forms and is associated with a number of congenital disorders. Wilms' tumor appears to be genetically heterogeneous although only a single Wilms' tumor suppressor gene, designated WT1, has been isolated to date. WT1 encodes a zinc finger protein and is mutated in a subset of Wilms' tumors and in patients with Denys-Drash syndrome (DDS), an association of Wilms' tumor and severe genitourinary defects. This thesis reports a mutational analysis of WT1, detailing the spectrum and frequency …  Lire la suite