McGill University Thèses et mémoires publiés en 2007

The impact of peatland restoration on Diptera assemblages was studied across multiple organizational levels (taxon, size class, trophic group) among abandoned-mined, restored and natural sites of three bogs and the environmental variables affecting those assemblages were determined. More than 22,000 individuals representing 716 species were collected using pan traps, sweeping and Malaise traps. Restored and abandoned sites were similar to each other and both distinct from natural sites as shown by small-size class, acalyptrate and trophic assemblages. However, abandoned sites showed much lower evenness and generally supported lower species richness than restored and natural sites, due to the dominance of …  Lire la suite

This study is an investigation of Kant's empirical realism as a response to the problem of intentionality. The former is the thesis that what we are related to in perception are the empirically mind-independent objects all around us in the spatio-temporal world. The latter is the problem of how thoughts come to have objective purport---how they come to represent states of the world. I argue that Kant has a sophisticated theory of how our 'faculty of cognition' puts us, as subject's of thought, in direct contact with the objective world. This theory shows us how intentionality is possible by showing …  Lire la suite

Wernicke's encephalopathy is a neuropsychiatric disorder resulting from thiamine deficiency (TD) and is characterized by neuronal loss, astrocytic proliferation and microglial activation. Cyclooxygenases (COX) are enzymes which catalyze the first step in the synthesis of prostanoids. COX-1 is expressed constitutively and COX-2 is the inducible isoform. Groups of TD rats and pair-fed controls were killed at presymptomatic and symptomatic stages of encephalopathy. Cresyl violet and NeuN staining showed decreased numbers of neuronal cells in vulnerable regions (medial thalamus and inferior colliculus) but not in a spared region (frontal cortex). Numbers of GFAP-positive and OX-42-positive cells were increased at symptomatic stage …  Lire la suite

Java Virtual Machines provide a layer of abstraction supporting any services required for the execution of Java programs; from the viewpoint of Java programs, a Java Virtual Machine is a kind of "virtual hardware". However, fundamentally, any job of this virtual hardware is done by the real low level hardware, and behavioural changes in the virtual hardware are eventually reflected by performance variations in the real hardware. Investigating the real hardware performance is thus important for understanding the behaviour of higher levels, including virtual machines themselves and the Java programs they run. Hardware information also has significant potential for optimizing …  Lire la suite

The Framework Convention on Climate Change has yet to deal with tropical deforestation although it represents an important source of greenhouse gas emissions. In December 2005 negotiations on a possible regime to reduce emissions from deforestation resume under the impulse of a regime proposal based on the concept of compensated reduction. Over the course of 2006 Panamanian policy-makers working within the National Environmental Authority (ANAM) determine that such a regime is in the interest of Panama given that the integrity of the Kyoto Protocol's existing flexibility mechanisms is protected. However reducing its deforestation rate is not currently possible for Panama …  Lire la suite

While the groundbreaking insights that contemporary theorists have formulated with regards to space---as a multiplicity without essence, as an active event, and as inseparable from subjectivity, power, Otherness and time---have ostensibly purged it of its traditional understanding as absolute, a specific visuality characteristic of Cartesian perspectivalism remains privileged in its theorization which force it to remain so. While the complexity of space cannot be recovered from an abstract contemplation of its visual geometry in a way that reflects these contemporary concerns, there have unfortunately been relatively few attempts to imagine space away from the visual in a way that challenges …  Lire la suite

Canada's commitment to the Kyoto Protocol provides agricultural producers with an opportunity to supply carbon offset credits to a domestic carbon market and receive revenue from the sale of these credits. This study employed the multiple bounded discrete choice method to estimate Quebec hog producers' willingness to accept compensation to adopt two management practices that reduce carbon emissions; i.e. reduced protein feeding and adopting a manure storage cover. The average willingness to accept compensation for reduced protein feeding was $46.71 per tonne of CO2 equivalent and for the manure storage cover was $40.40 per tonne of CO2 equivalent. In addition, …  Lire la suite

Cette thèse regard l'impact des changements environmentales sur la récolte des aliments traditionnels et characterise l'implication de ses changements sur la diète des membres de la communauté. Une combinaison de méthode quantitative et qualitative ont été utilisé pour documenter et estimer la séquence de la récolte des animaux clées locales. En général, les résultats entre la nourriture disponible estimé provennant de la récolte et le montant estimé pour la consumption alimentaire n'étaient pas égaux, parcontre, la ratio entre aurignal et poisson blanc étaient bonne. La relation entre les résultats numériques concernent la récolte et la consumption alimentaire sont complèxes et …  Lire la suite

Multiple Sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system. The etiology of MS is unknown but many researchers believe that it is autoimmune mediated. This study investigated naive CD4+ and naive CD8+ T-cell homeostasis in patients with Primary Progressive Multiple Sclerosis and Relapsing Remitting Multiple Sclerosis. The naive T-cell compartment involves a balance between thymic production of naive T-cells, homeostatic proliferation and the delivery of death and survival signals. Naive T-cell production was quantified by measuring signal joint T-cell receptor excision circles (sj-TRECs); episomal byproducts formed during V(D)J T-cell receptor rearrangement. Homeostatic proliferation was …  Lire la suite

The role of redox reactions in the formation of aroma volatiles, colour and other non-volatiles in the Maillard Reaction was investigated. The electrochemical properties of individual reactants and Maillard model mixtures were monitored via ORP (oxidation-reduction potential) and oxygen electrodes. All models exhibited unique electrochemical activities represented by their corresponding ORP profiles. Investigation into the redox potentials of several model systems demonstrated that the increased negative value of a redox potential is not necessarily correlated with its browning potential. An optimal redox potential range, where browning is favoured, was found to represent a balance between carbonyl and hydroxyl moieties in …  Lire la suite

Aspergillus niger and Penicillium candidum were grown and harvested on days 6 and 8, which corresponded to their maximal biomasses and lipoxygenase (LOX) activities. The extracts were enriched with ammonium sulfate precipitation at 30 to 70% and 20 to 60% of saturation, respectively. The LOX activity was assayed with linoleic, linolenic and arachidonic acids as substrates. Both enriched microbial LOXs demonstrated preferential substrate specificities towards free fatty acids, over acyl esters of linoleic acid. The LOXs had the highest catalytic efficiency values (ratio of V max to Km) for linolenic acid biocatalysis. Major and minor pH optima at 5.0 and …  Lire la suite

This thesis presents a formal framework for the analysis of execution traces collected from distributed systems at run-time by monitoring. It introduces the notions of event and message traces to capture the consistency of causal dependencies between the elements of a trace. The two formal trace models are based on the partial order and lattice theory, where the lattice of a partially ordered trace can be used as an efficient means to check properties on the trace. We formulate an approach to property testing where a partially ordered execution trace is modeled by a collection of communicating automata. Then, we …  Lire la suite

As the debate over demarcation between airspace and outer space remains unresolved, advancements in technology are bringing these two realms of flight closer than ever before. Rather than relying on traditional functional or spatial approaches to define the legal framework of flight, this paper proposes a completely new legal system based on orbital status known as "Orbit Law." The first chapter examines the functional versus spatial debate, and highlights those aspects of existing International Air Law and Space Law which may be useful to an Orbit Law regime. Chapter II studies the science bridging air flight with space flight, and …  Lire la suite

Amplification of the receptor tyrosine kinase ErbB-2 has been linked to the proliferation of breast cancer cells.1,2 Trastuzumab targets the extracellular domain of ErbB-2, leading to growth inhibition of approximately 15% of the breast cancers with genomic amplification of the ERBB2 gene.3 Clinical studies have demonstrated its efficacy in both early4 and metastatic breast cancers. 5,6 However, many tumors with ERBB2 amplification are not responsive to treatment.7 Moreover, the ones that initially respond, eventually progress and acquire drug resistance.8 An in vitro model for this acquired resistance was established by Chan & al.9 The breast cancer cell line, BT474, containing …  Lire la suite

Le blé à pain (Triticum aestivum L. em. Thell.) est la culture la plus importante au Canada. Le flétrissement des plantules des céréales causé par Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein) Petch] est la maladie du blé la plus dévastatrice en Amérique du Nord. Elle cause des pertes tant dans le rendement que dans la qualité du grain. La résistance est le moyen le plus efficace pour gérer cette maladie. Une variabilité spatio-temporelle élevée rend difficile et coûteuse l'évaluation de la résistance basée sur les symptômes. Le développement de moyens abordables, rapides, et à haut débit pour le criblage …  Lire la suite

Microtubule-associated protein tau binds to microtubules and stabilizes microtubule structure. By stabilizing the microtubule cytoskeleton, tau plays an important role in the maintenance of neuronal survival. Tau is abnormally hyperphosphorylated and forms neurofibrillary tangles (NFTs) in the brains of the patients suffering from a number of neurodegenerative diseases termed tauopathies, which include Alzheimer's disease (AD) and frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17). Missense tau mutations have been discovered to cosegregate with FTDP-17. The mechanism by which these mutations promote tau hyperphosphorylation and NFT pathology remains unknown. The goal of this study was to determine the mechanism by …  Lire la suite

The root system is a vital and dynamic part of a plant throughout its lifetime. Its spatial distribution is the consequence of multiple interactions with the surrounding soil medium. In particular, the presence of pathogens in soil may influence the development of the plant, especially the below-ground part, in both its physiology and its structure. Studies of diseased plant roots may take different approaches and investigate disease effects at different levels. In this study, two groups of four potato (Solanum tuberosum L.) plants were grown in middle-sized plastic pots in a greenhouse, and their root systems, together with the soil …  Lire la suite

Time alignment is performed on a conventional PET scanner in order to reduce the noise in the image from undesirable interactions, called randoms. In time of flight scanners this alignment is even more critical in order to place the position of an annihilation accurately. Traditionally, the alignment is an iterative process done by adjusting time offsets and recording the count rate until it is maximized. We have designed and built a positron detector that can be placed in the PET scanner. This enables each crystal in the scanner to be aligned to the same event (the positron detection), providing a …  Lire la suite

This thesis analyses the extraterritorial dimension of patent systems in light of recent judicial trends, ending with the United States Supreme Court's landmark 2007 ruling in AT&T v. Microsoft. The discussion examines (i) the economic interest of nations in issuing and maintaining patent rights; (ii) the legal arguments against a unilateral extraterritorial extension of domestic patents, leading to the legal presumption against extraterritorial extension; (iii) the evolution of this doctrine in United States legislation and jurisprudence and forays against it, especially in recent decades; and (iv) the impact of globalization and of the nature of patentable information in the digital …  Lire la suite

I present a method that regroups cis-regulatory modules by shared sequences motifs. The goal of this approach is to search for clusters of modules that may share some function, using only sequence similarity. The proposed similarity measure is based on a variable-order Markov model likelihood scoring of sequences. I also introduce an extension of the variable-order Markov model which could better perform the required task. Results. I show that my method may recover subsets of sequences sharing a pattern in a set of generated sequences. I found that the proposed approach is successful in finding groups of modules that shared …  Lire la suite

Objectifs La bonne nutrition et les probiotiques ont prouvé réduire la sévérité de la colite. Cependant, leur impact sur le métabolisme des protéines gastro-intestinales et hépatiques n’a pas encore été étudié. Notre objectif premier était de comparer l’effet indépendant des probiotiques à celui d’un régime alimentaire adéquat, sur la synthèse des protéines, chez le porcelet présentant une colite, recevant une diète restreinte en macronutriments. Le but secondaire de cette étude était de déterminer les contrastes histologiques ainsi que les variations au niveau des marqueurs du stress oxydatif, résultant de l’effet des probiotiques dans les deux cas de malnutrition et de …  Lire la suite

The present study intends to contribute to the work undertaken in Quebec and in France on religious pluralism in the public sphere. The first section examines the common approach adopted by both States which allowed students to wear religious symbols in public schools. We then highlight the divergent approaches that emerged in 2004 when the French legislature prohibited almost entirely this practice. The second section assesses the capacity of Quebec's and France's legal and political approaches to ensure social cohesion, to protect freedom of religion, the right to equality as well as the rights of the internal minorities who are …  Lire la suite

Numerous artists and scholars advocate a literary consideration of graphie novels. However, their arguments seldom present a clear analysis of what makes graphie novels literary, let alone a clear definition ofliterature. This thesis seeks to fill in these explanatory gaps by arguing for the literary consideration of graphie novels, understood as a genre within comics, on the basis of an institutional theory of literature. As this theory posits a shared practice of production and appreciation of artistic value, the value of a literary work is not exclusively tied to the linguistic medium. On the contrary, pictures can significantly contribute to …  Lire la suite

The goal of this thesis was to create a novel stable water-soluble azo polymer with photoswitchable properties, which was to be used as a scaffold in directing neuron growth. The new polymer, PDR2, was synthesized and extensively characterized to understand its physical and chemical properties, as well as to ascertain the structure. Characterization techniques included nuclear magnetic resonance, thermogravimetric analysis, differential scanning calorimetry, absorption spectroscopy, and ellipsometry. The photoresponsive properties of the polymer were then studied by examining quantum yields and birefringence, and the variation of these properties with humidity was examined, after being deposited onto thin films using layer-by-layer …  Lire la suite

Biological invasions are a global phenomenon that can threaten native species and disrupt ecosystem processes. Exotic species also impact ecosystems in less conspicuous ways by provoking native species to alter their foraging behaviour. Subtle impacts such as diet shifts are frequent, and can have consequences for food web dynamics and the fitness of native predators. Diet shifts involving the consumption of exotic species require native predators to recognize, capture and handle novel prey. In this thesis, I document a diet shift in the St. Lawrence River involving a common native fish and Eurasian mussels that invaded the river in the …  Lire la suite

Satellite capabilities greatly enhance both the military and civilian sectors of society. Anti-satellite (ASAT) weapons pose a serious risk to all satellites. Chapter One of this thesis discusses current satellite capabilities. Chapter Two, details the wide variety of ASAT weapons. Chapter Three turns to the intentions of various States to employ ASATs. Chapter Four analyzes the legal implications of using force against satellites---beginning with the laws relating to the use of force in general, including the right of self-defense, and then progressing through relevant provisions of the laws of armed conflict. It also addresses the debate over the militarization and …  Lire la suite

Diamonds have been discovered in a variety of potassic ultramafic rocks including group-I and group-II kimberlites, olivine lamproites and aillikites, all of which are macroscopically similar and can be difficult to differentiate when viewed under the microscope. However, group-I kimberlites, and to a much lesser extent group-II kimberlites and olivine lamproites, are known to contain economic concentrations of diamonds. This study addresses the problem of distinguishing among different types of kimberlitic and related rocks by developing a geochemically-based method for classifying them. Geochemical methods have been largely ignored in the classification of kimberlites and related rock types due to high …  Lire la suite

Although there is a marked increase in the number of surviving motets from the early sixteenth century, the context in which they were performed remains a mystery. The first five printed anthologies of motets, published by Petrucci in Venice between 1502 and 1508, include a significant proportion of Marian motets (95 of the 174 pieces). In the first chapter I provide evidence that these polyphonic Marian motets were used in the Venetian confraternities, or "scuole." The second chapter draws connections between the musical needs of the scuole and the Marian text types of the motet anthologies. The final chapter looks …  Lire la suite

This study attempts to expand existing knowledge on the relationship between biodiversity and ecosystem functioning, by studying a four year old tropical tree plantation. The growth of trees coming from monocultures, three species mixtures and six species mixtures was compared. Through multivariate statistical analysis, the variation in tree productivity was partitioned into different components: variation explained by (1) species richness, (2) species identity and (3) the environment. Results reveal that the environment explains the largest portion of variability in tree growth. Moreover, of the small amount of variation explained by diversity, species identity is found to be twice as important …  Lire la suite

Stroke is a leading cause of death and disability in Western countries and it is estimated that up to 70% of stroke survivors have a long-lasting disability of the upper limb. The purpose of this study was to examine plasticity at the neuronal level to distinguish between recovery and compensation and how this relates to recovery of arm movement at the behavioural and functional levels in five chronic stroke patients. Brain activation patterns associated with a pointing movement involving the whole arm were identified over two baselines and one post-training intervention evaluation. At each evaluation, a clinical physical and cognitive …  Lire la suite

Unplanned ore dilution or stope overbreak, which has a direct and large influence on the cost of a stope, and ultimately on the profitability of a mining operation, can be attributed to both the mining process and to geologic setting. The research undertaken in this document, applicable to a wide range of underground mines employing the blasthole mining method to extract tabular orebodies, focuses on examining factors attributable to the generation of unstable stope hanging-walls. The primary objective of the research undertaken is to establish new models for stope and orezone design, with respect to anticipated stope overbreak, focusing on …  Lire la suite

This study addresses the mechanisms and consequences of shifts and transitions at the apex of the international hierarchy of power. It begins with the assessment that in spite of recent advances, progress in this area has been limited by lack of theoretical consistency and rigor. To remedy this problem, a game-theoretic model is developed which conceives of power shifts as transitions in preferences and learning processes. The model is then tested against the case of the pre-World War I British-German power shift. Findings provide new insight into the dynamics of prewar European diplomacy, and suggest that the war fundamentally resulted …  Lire la suite

Mason, Lorne (Internal/Cosupervisor2)  Lire la suite

Résumé Dans son oeuvre, J.M. Coetzee démonte le concept Cartésien de la vie humaine, pour laquelle le corps perd so importance et n'est qu'un enrobage pour l'esprit, qui lui règne sur le tout. Ses romans démontrent que cette vision dualiste renferme le sujet dans ses propres pensées, ce qui l'éloigne de son proper corps, du monde, et d'autrui. Pour Coetzee, cette vision dualiste des Européens leur a causé de percevoir les indigènes comme des Autres absolus avec lesquels ils ne peuvent s'identifier. Cette vision est à la base de l'esclavage et de la colonisation. Pour constuire son proper concept de …  Lire la suite

Pollard, Wayne H. (Supervisor2)  Lire la suite

Only a small proportion of persons with stroke fully recover the use of their more affected upper extremity. The consequences of this are devastating as use of the upper extremity is of the utmost importance to the performance of daily activities. Rehabilitation post-stroke is now being offered in a variety of different settings including acute and rehabilitation hospitals, out-patient rehabilitation centers, at home through home-care and in the community. Evaluating improvement in upper extremity function is difficult because there is no agreed upon measure or set of measures. The proliferation of tests targeting a particular type of client (severe, high …  Lire la suite

L'objectif de ce mémoire est d'examiner en profondeur les contacts étrangers de la résistance allemande avec le gouvernement britannique, plus précisément entre l'arrivée au pouvoir du Premier Ministre Chamberlain en mai 1937 et les Accords de Munich du 30 septembre 1938. Les contacts examinés incluent Carl Goerdeler, Ludwig Beck, Ewald von Kleist-Schmenzin, Ernst Freiherr von Weizsäcker, ainsi qu'Erich et Theodor Kordt. Le but primordial de ce mémoire est de tenter de comprendre le développement de la politique d'apaisement de Chamberlain jusqu'aux Accords de Munich, et comment l'information reçue par l'entremise de ses contacts dans la résistance allemande a influencé la …  Lire la suite

Due to recently reported increases in non-suicidal self-injury (NSSI) among adolescents and young adults in the community, researchers have begun to examine the role of social influence and functions of NSSI on the initiation and maintenance of these behaviours among youth. The present study sought to examine the role of social influence on the initiation of NSSI, as well as test a functional reinforcement model of NSSI within a sample of college students. A series of psychosocial measures were completed by 56 first-year university students who reported engaging in NSSI, and results indicate that the majority of respondents learned about …  Lire la suite

From 1981 to 1986, the Reagan administration viewed Nicaragua's Marxist regime as a threat to regional and U.S. national security. The administration's support of the Contra rebels, who were actively fighting to overthrow Nicaragua's government, embroiled the U.S. in a "limited" regional war. While conventional scholarship has characterized this conflict as "Reagan's War", Congress played a significant role in keeping the Contra army active and intact. Caught between Reagan's strident anti-Communist ideology and the fear of a Marxist state in Central America, Congress attempted to establish a middle-of-the-road policy, first cautiously funding the Contras through covert operations and non-lethal aid, …  Lire la suite

Motivated by the physiological phenomena of collapse and flow limitation for a serial pulmonary artery stenosis, we investigated the three-dimensional influence of spatial configuration on the wall motion and hemodynamic. Our numerical study focused on the effect of two geometrical parameters: the relative distance and the angular orientation between the two stenoses. The collapse of a compliant arterial stenosis may cause flow choking, which would limit the flow reserve to major vital vascular beds such as the lungs, potentially leading to a lethal ventilation-perfusion mismatch. Flow through a stenotic vessel is known to produce flow separation downstream of the throat. …  Lire la suite

This research examines the ways that socially mediated writing processes facilitate membership in communities of practice. Writing practices are located within rhetorical contexts and as newcomers to a community participate in community practices, they learn to recognize the rhetorical context in which they are writing. As their competence in the rhetorical context increases, they move from a position of peripheral membership in that community to a position of full participation or membership. Drawing on theories of practice and genre to understand the ways that writing practices form communities and shape membership, the research investigates the Canadian Association for the Study …  Lire la suite

Concrete deteriorates over time due to environmental changes and/or poor construction processes which can eventually lead to partial or total failure of a structure. Deterioration in concrete manifests itself in different forms such as: freeze and thaw, chemical attack, surface and internal flaws. Concrete and shotcrete linings are widely used as support systems in underground excavations. Surprisingly, a fragmented, damaged shotcrete support system can actually create a less stable environment than the unsupported rock mass. Detection of internal flaws remains a difficult task as they are not always observable on the surface. Yet, the potential to expand and cause damage …  Lire la suite

The main focus of my PhD studies was aimed at understanding the general mechanism of nuclear translocation and isolating novel components of the nuclear translocation pathway in neurons. Using the Drosophila visual system as an in vivo model to study nuclear motility in developing photoreceptor cells (R-cells), I have identified a novel role for the Ser/Thr kinase Misshapen (Msn) and the endocytic trafficking pathway in regulating the nuclear translocation process. The development of R-cells in the Drosophila eye disc is an excellent model system for the study of nuclear motility owing to its monolayer organization and the stereotypical translocation of …  Lire la suite

G protein-coupled receptors (GPCRs) comprise the largest family of transmembrane receptors. The beta-arrestins, adaptor proteins involved in GPCR desensitization, may also act as scaffolds for signaling pathways such as the mitogen-activated protein kinase (MAPK) cascade. The MAPK family, which includes the extracellular-signal regulated kinases (ERK) 1 and 2, promotes cellular differentiation and proliferation. Herein, the activation of ERK1/2 upon stimulation of the GPCR bradykinin type 2 receptor (B2R) with bradykinin was examined. Various B2R mutants with modified C-termini were employed to examine the temporal kinetics of ERK1/2. One of these receptor mutants displayed a loss of beta-arrestin binding as well …  Lire la suite

The Canadian agricultural sector was recognised as a potential seller of carbon offset credits in the domestic emission trading system. A number of beneficial management practices may reduce GHG emissions while increasing production efficiency and profitability of agricultural activities. A contingent valuation survey was used to estimate the carbon offset price at which feedlot operators in Ontario would adopt two management practices that reduce GHG emissions: adding roasted soybean seeds to a cattle diet and increasing the intensity of feedlot operations. The value elicitation questions to estimate the mean WTA compensation were designed using a multiple bounded discrete choice format …  Lire la suite

Maintaining a safe water supply is particularly crucial for karst islands such as Barbados. In order to take proper measures to prevent and reduce saltwater intrusion and to safely extract the right fraction of recharge, karst characteristics must first be fully understood. Geomorphologic investigations of karst surface features of the Porters & Trents groundwater catchments (Barbados) employed GIS technologies to explore the development and distribution of sinkhole features. Contour-based digital elevation models, surface geology, lithology, and remote sensing images were incorporated in this investigation. Seventy-six sinkholes were investigated and occupied approximately 1% (0.16 km2) of the total area (16.41 km2) …  Lire la suite

ABSTRACT The application of dynamic testing to civil engineering structures provides a means to understanding a structure’s dynamic properties. Such testing includes Forced Vibration Test (FVT), Earthquake Response Test, Ambient Vibration Testing (AVT), and Free Response Test. AVT has become a popular dynamic testing methodology due to its practical and economical advantages. In this research, the feasibility of employing AVT to obtain reliable fundamental frequencies of buildings was studied by performing AVT inside the Burnside Hall building of McGill University. All measurements were taken by two pairs of CityShark II Microtremor Acquisition and velocimetres. Three system identification approaches, direct Fourier …  Lire la suite

The detection threshold of a luminance-defined Gabor is improved by two high contrast, aligned flanking Gabors, an effect termed collinear facilitation. However, the neural basis of collinear facilitation is not well understood. This thesis focuses on a number of issues in collinear facilitation to better our understanding of its neural basis. (1) Cortical sites: the cortical site of collinear facilitation was investigated, and results showed that collinear facilitation is a purely monocular phenomenon. (2) Temporal properties: Collinear facilitation has fast dynamics for initiation and once collinear facilitation occurs it either decays slowly or is associated with a sustained detection. (3) …  Lire la suite

The PAX gene family of transcription factors plays a prominent role during embryogenesis however can be aberrantly re-activated during tumorigenesis and contributes to the malignant phenotype. During embryonic kidney development, PAX2 exerts an anti-apoptotic function however its expression typically attenuates during the post-natal period. On the other hand, PAX2 aberrant expression is observed in the majority of Renal Cell Carcinomas (RCC). RCC is resistant to chemotherapy; up-regulation of anti-apoptotic genes is recognized to contribute to tumor resistance to chemotherapy. We hypothesized that the anti-apoptotic effect of the PAX2 gene that is expressed in RCC cells contributes to RCC and their …  Lire la suite

Nerve growth factor (NGF) is a neurotrophin important for the survival, growth and function of cholinergic basal forebrain neurons. However, little is known about the function of NGF on other basal forebrain neurons such as glutamatergic or GABAergic neurons. Here, we used neurons from the rat medial septum/diagonal band of Broca (MS-DBB) to test whether chronic exposure to NGF affects the synaptic function of cholinergic, glutamatergic and GABAergic basal forebrain neurons. We isolated single rat MS-DBB neurons in culture, allowing them to establish synaptic contacts onto themselves. One group of neurons chronically received NGF while another group received none. After …  Lire la suite