McGill University Thèses et mémoires publiés en 2007

Inclement climate conditions have made the Arctic Ocean logistically difficult to study, and thus, our historical knowledge of Arctic Ocean processes are limited. Recent observations indicate rapid and abrupt changes in climate. These changes are thought to includes rising temperatures, increase storm activity, altered freshwater balance and a notable decrease in the concentration and extent of sea ice covering the Arctic Ocean. Increasing awareness of these changing conditions and our poor knowledge of how the physical environment influences carbon fluxes, planktonic productivity and biogeochemical cycling have lead to international efforts to address these questions. The data presented here addresses biogeochemical …  Lire la suite

This thesis investigates the possibility of exploiting haptic force-feedback technology for interacting with virtual musical instruments. A survey of current software solutions for creating haptic virtual environments is provided, with a discussion on the need to integrate such a platform with currently accepted solutions for audio research. A system was developed to combine a haptic programming library with a physical dynamics engine and to expose its functionality through the Open Sound Control (OSC) protocol, an increasingly accepted standard for communication within the audio software and hardware domain. Using OSC messaging, simple 3D objects can be instantiated and constraints on their …  Lire la suite

Glucocorticoids are commonly used to treat cows with clinical ketosis and fatty liver disease. This study investigated the effects of 10 mg/mL of FlucortRTM and PredefRTM 2X on the day of calving on blood metabolites, immune function and milk composition on 30 transitional Holstein cows. Sample of blood and milk were analyzed for energy metabolites (glucose, NEFA, BHB and insulin), mineral metabolites (Ca, P, Na, K, Cl and Mg), energy function parameters (antibody, lymphocyte), milk compositional parameters (protein, fat, lactose, SCC). There were no differences in glucose, Na, Cl, Mg, antibody, lymphocyte and milk fat, were observed among treatments. FlucortRTM …  Lire la suite

Neonates that survive very preterm birth have a high prevalence of cognitive impairment in later life. A common factor detected in premature infants is their postnatal exposure to high oxygen tension relative to that in utero. Hyperoxia is known to elicit injury to premature lung and retina. However, the potential role of exposure of the developing brain to elevated O2 levels has been relatively overlooked. We hypothesized that cerebral damage may in part be due to hyperoxia-mediated microvascular degeneration; therefore, the central aim of this work was to elucidate how hyperoxia affects the newborn cerebral vasculature and impacts brain function. …  Lire la suite

The reaction of nitric oxide with secondary amines to form diazeniumdiolate anions with the structure R2NN2O2 - has been studied in order to investigate the stereochemistry and mechanism of this reaction. The stereochemical preference of the cis (Z) isomer for these compounds was proved using vibrational spectroscopy, namely infrared spectroscopy (IR) and Raman. Theoretical (B3LYP/aug-cc-pVDZ) rotation barriers for the simple diazeniumdiolate anion, Me2NN(O)=NO- are calculated in the gas phase to be 26.2 kcal/mol with the cis isomer predicted to be stabilized by only 0.5 kcal/mol compared to the trans isomer, therefore stereochemical preference for the cis is due to kinetic …  Lire la suite

Two conflicting processes are believed to influence the relationship between taxonomic and ecological diversity: adaptive radiation and niche conservatism. No consensus has yet emerged regarding the conditions that favour conservatism of traits due to common ancestry over adaptive radiation and the resulting ecological divergence. Carex is an ideal group for studying these phenomena, as it is incredibly diverse taxonomically and ecologically, and includes many recently formed lineages. I chose a group of eight closely related Carex taxa from eastern North America as the focus of my study. Multivariate analysis of 30--33 morphological variables measured on 456 plants from 110 populations …  Lire la suite

Multi-religious and multi-ethnic democracies face the challenge of constructing accommodative arrangements that can both facilitate cultural diversity and ensure women's rights within religio-cultural groups. This thesis is an investigation of the Indian state's policy of legal pluralism in recognition of religious family laws in India. The Indian state has adopted a model of what I have termed "shared adjudication" in which the state shares its adjudicative authority with internally heterogeneous religious groups and civil society in the regulation of marriage among Hindus and Muslims. Combining theoretical frameworks of state-society relations, feminist theory, and legal pluralism, and drawing from ethnographic research …  Lire la suite

Psychological stress increases dopamine release in the striatum and is thought toplay a role in susceptibility to psychotic illness. In schizophrenia, a prototypicalpsychotic illness, there is evidence of abnormal dopamine response to pharmacologicalchallenge or psychological stressors. Stress, like dopamine agonist drugs, can triggerrelapse in schizophrenic patients. It has been proposed that exaggerated responses tostress are key in the etiology of psychosis in vulnerable individuals. However, it is notknown whether differences in brain dopaminergic responsiveness precede psychosis ordevelop subsequent to illness onset.  Lire la suite

Human stance in quiet mode, relies on feedback from eyes, skin, muscles and the inner ear and the control produced is a combination of strategies which enable a person to stay standing. This thesis presents the simulation and control of a hip actuated robotic model of human standing posture. The first part of the thesis is devoted to recalling basic elements of the human balance system and to describe the balance strategies it uses to maintain an upright stance. Of the strategies presented, we consider the hip strategy which motivated the formulation of a hip actuated robot. An investigation into …  Lire la suite

The performance of bone (osseous) implants is critically dependent on the interactions of the implant surface with the surrounding osseous tissue. Correlating surface topography with bioperformance is essential for the optimized design of osseous implants. The goal of this thesis is to develop a robust methodology for the measurement and analysis of aperiodic surface topographies, such as those encountered on bone implants, over multiple length scales. Two widely used measurement techniques, namely, Atomic Force Microscopy (AFM) and White-Light Interferometry (WLI), are compared and contrasted. A custom-designed MATLAB-based program is developed to analyze the images from both tools, and to extract …  Lire la suite

This thesis is a project in narrative New Testament ethics. It offers a fresh reading of the material in Luke-Acts that concerns wealth and possessions, beginning with two primary premises, which are developed in Part 1: (1) The descriptive and synthetic activities traditionally accorded to New Testament ethics are not fully separable from the hermeneutical and pragmatic concerns usually considered the domain of theological ethics. (2) The conceptualizations of the moral life readers bring with them to the biblical text will influence the reading strategies they employ and thus the critical readings that result. Based on these premises, this thesis …  Lire la suite

Earthworms are well known to increase decomposition of organic matter and release of plant available nutrients. They can also increase CO 2 and N2O fluxes from the soil by stimulating respiration, denitrification, and nitrification caused by soil microorganisms. The objective of this thesis was to examine the influence of different earthworm species and population numbers on CO2 and N2O fluxes from a corn agroecosystem. In the field study, earthworm treatments had a significant effect on CO2 fluxes, but there was no difference between CO 2 fluxes from the two species (Lumbricus terrestris L., Aporrectodea caliginosa Savigny) or from the two …  Lire la suite

In this thesis I present a simple, computationally-inexpensive moist turbulence model in order to study the differences between moist and dry turbulence. The model is validated by comparing a moist-bubble simulation with ones presented in Grabowski and Clark (1993) using a more-sophisticated model. We show that the outputs compare well and that our model can easily be extended to higher resolutions due to its simplified equations and uncomplicated implementation. Measurements of liquid water content spectra from the 3843 validation run are shown having shallow slopes, implying that moist processes require high resolution. Consideration is also given to the issue of …  Lire la suite

The first part of my master's thesis in creative writing explores the way the leading character's identity is structured as a function of memory. The protagonist, limited to a confined space, does not have access to his existence other than through the senses which are drawn from different episodes of his past. These reminiscences, that open the way to experience, forge his becoming, and allow him to superimpose his own individual path to memories that he has of those persons who have shaped his experience of the world. The critical part of my work concerns the genesis and the elaboration …  Lire la suite

Naturally-occurring CD4+Foxp3+ regulatory T cells (nTreg) play a central role in maintaining immune self-tolerance as well as modulating immunity towards pathogens. Pathogens may establish chronic infections in immunocompetent hosts by engaging nT reg in order to promote immunosuppression. The goal of the research described here is to test the hypothesis that nTreg modulate protective immunity to malaria, and consequentially affect susceptibility to the parasite. To investigate this question, the functional dynamics of CD4+Foxp3 + nTreg cells were evaluated in mice infected with blood-stage Plasmodium chabaudi AS. Adoptive transfer of nTreg to infected wild-type C57BL/6 (B6) mice or infection of transgenic …  Lire la suite

Peter Henry Radziszewski (Internal/Supervisor)  Lire la suite

ABSTRACT The Sequential Insertion of Carbon Monoxide and Imines into Nickel-Carbon Sigma-Bonds and Kinetic Analysis of Imine Insertion into Palladium-Acyl Sigma-Bonds The coupling of imines and carbon monoxide mediated by late transition metals has been previously reported in the Arndtsen laboratory. The fundamental properties of 2,1-migratory insertion of imines into nickel- and palladium-acyl bonds are presented in this text. This study investigates the use of neutral eta2-N,O-salicylaldiminato nickel (II) systems (Chapter 2) as potential complexes to mediate the sequential insertion of carbon monoxide and imines. These complexes undergo rapid carbon monoxide insertion. Subsequent imine insertion is permitted when the imine …  Lire la suite

The purpose of this thesis is to locate the experience of individuals in the shared experience of a cultural community, to reveal a collective experience. Further, this thesis aspires to demonstrate that the experience of trauma is transmitted, often silently, intergenerationally. This is an attempt to define a community of distant survivors, and to locate the echoes of the voice of trauma hidden in the narratives of its members. The study explores the events of the December 2004 Southeast Asian tsunami. At the moment of the tsunami disaster all the participants in this study, Indonesian International Students, were studying in …  Lire la suite

Serres, Sophie Jeannine De (Internal/Cosupervisor2)  Lire la suite

The library is an obsessional site in literary modernism. From the incendiary impulses of F. T. Marinetti to Walter Benjamin's sedate unpacking of his library, modernists characterize the library as a repository of the material past. In particular, Henry James, Edith Wharton, and E. M. Forster demonstrate a striking attunement to the materiality of books, archives, and libraries in their fiction. In The House of Mirth, books are aesthetic objects as well as commodities that advertise cultural capital. The contents of a private archive threaten public scandal in The Aspern Papers. Private libraries display cultural taste in Howards End and …  Lire la suite

This doctoral dissertation focuses on the negotiation of power in schools and the social and academic experiences of First Nations and Metis children who speak a non-standard variety of English called Indigenous English. Indigenous English is a dialect of English spoken by many Indigenous peoples in Canada; it is especially discernable in the Prairie Provinces, yet it is not widely recognized by the majority of the population. This thesis explores the experience of dialect speakers of Indigenous English in the standard English School and educator perceptions of their literacy and language abilities. This classroom study was conducted in an urban …  Lire la suite

We have developed methods to obtain pristine permafrost/ground ice samples from the Canadian high Arctic and demonstrated that these methods are suitable for both culture-dependent and culture-independent microbiological analyses. In an initial study, the culturable microbial community in a 9 m deep permafrost sample was dominated by spore-forming genera of Bacteria from the phylum Firmicutes while the phyla Actinobacteria and Proteobacteria were also represented. Phenotypic characterization of the isolates indicated a predominantly psychrotolerant and halotolerant microbial community. A culture-independent survey of the microbial diversity in this sample revealed higher diversity, as Bacteria from 6 phyla (Actinobacteria, CFB, Firmicutes, Gemmatimonadetes, Planctomyces …  Lire la suite

Dans ce travail nous avons développé deux nouveaux détecteurs qui visent à améliorer l'exactitude de la dosimétrie relative et de référence en radiothérapie: une chambre d'ionisation liquide gardée (GLIC) et un calorimètre d'eau scellé pour les électrons (ESW). Avec la GLIC nous avons visé à développer un détecteur indépendant de l'énergie et libre de perturbations avec une résolution spatiale élevée pour la dosimétrie relative. Nous avons atteint une stabilité suffisante pour des mesures à court terme en utilisant la GLIC-03, qui a un volume sensible d'approximativement 2 mm3. Nous avons évalué la recombinaison générale des ions dans des faisceaux de …  Lire la suite

Although custom-made foot orthotics are commonly prescribed to relieve lower limb injuries, few studies have documented their effects on the biomechanics of locomotion. The objective of this project was to quantify the effect of orthotic wear on kinematic, kinetic and electromyographic characteristics of the legs during walking and running. Fourteen subjects with custom-made foot orthotics were asked to run and walk over a 10-m walkway. Kinematic, kinetic and electromyographical parameters were recorded during all trials. One-way repeated measures ANOVA and paired students t-tests were used to evaluate the effect of orthotic wear as well as foot type (flat, normal). With …  Lire la suite

The creation and manipulation of infinite images is central to Bruno's thought, but to the best of my knowledge, this has never been properly treated before. This project is a departure from much of the current scholarship on Bruno which has focused on his contribution to scientific thought, and downplayed or ignored the Hermetic and magical elements which pervade his work. Each chapter deals with different works of Bruno, and different aspects of his philosophy, and each is rooted in the larger project of uncovering the role, meaning, and application of images in Bruno's thought. The general arc of the …  Lire la suite

Contemporary liberal democratic societies currently enact immigration policies that are morally indefensible from a liberal autonomy and social justice perspective. In a world characterized by stark inequalities in individual opportunities to lead autonomous lives, and in which many individuals lack the basic conditions for autonomous functioning, I argue that contemporary immigration regimes that distinguish between desirable immigrants---who are typically from similarly wealthy countries---and undesirable one ---who are typically members of the global poor---conflict with liberal commitments to individual autonomy and equality of opportunity. I advocate that such commitments should lead wealthy countries to change their criteria for immigration, so that …  Lire la suite

This article examines the relationship between spending on active labour market welfare programs (ALPMs) and attitudes towards two decomposed aspects of globalization: immigration and trade liberalization. Two empirical analyses related to this topic are carried out using cross-national survey data. The result is that ALMP spending has a positive impact on attitudes towards globalization. This finding suggests that governments can use targeted ALMP spending to counteract negative attitudes towards globalization and therefore ensure continuing economic benefits from trade liberalization and immigration.  Lire la suite

Virtual reality environments (VEs) are new tools to improve functional recovery in stroke survivors. Elements essential to maximize motor learning, can be optimized in VEs. Study objectives were: (a) to determine whether training in VE with enhanced feedback about movement patterns, leads to greater gains in arm movement quality, motor performance and decreased compensation compared to training in a similarly designed Physical environment (PE); (b) to estimate whether impairments in cognitive functioning affected the changes observed after training. Twelve stroke survivors practiced 72 pointing movements in VE or PE for 10 sessions with enhanced feedback. Kinematic analysis of pointing task, …  Lire la suite

Temporal lobe epilepsy (TLE) is the most common form of adult epilepsy. Magnetic resonance imaging (MRI) and electroencephalography (EEG) studies have shown that the hippocampus plays a principle role in epileptogenesis. Recent clinical studies have additionally implicated extrahippocampal brain structures as important participants in TLE, including the perirhinal cortex (PC) and the insular cortex (IC). Modelling TLE with animals rendered epileptic (chronic models of TLE) have corroborated such clinical findings, and have enhanced our understanding of the pharmacology and network interactions that occur during sustained limbic seizures. Due to certain constraints associated with the chronic models, however, brain slices treated …  Lire la suite

A model-driven approach to scenario-based requirements engineering is proposed. The approach, which is based on Computer Automated Multi-Paradigm Modeling (CAMPaM), aims to improve the software process. A framework is given and implemented to reason about models of systems at multiple levels of abstraction, to transform between models in different formalisms, and to provide and evolve modeling formalisms. The model-driven approach starts with modeling requirements of a system in scenario models and the subsequent automatic transformation to state-based behavior models. Then, either code can be synthesized or models can be further transformed into models with additional information such as explicit timing …  Lire la suite

Le but de cette dissertation était l’étude du phénomène de création et de développement de programmes de gestion des connaissances (GC). L’intérêt pour les programmes de gestion des connaissances a augmenté au cours de la dernière décennie face à la demande de recherche en éducation de gestion des connaissances et à l’importance de l’émergence de l’économie du savoir. Cette recherche exploratoire et explicative examine deux programmes d’études supérieures en gestion des connaissances conçus en I”an 2000. Le modèle théorique du cycle du savoir de Choo a été utilisé pour cette étude et a fourni une structure d’interprétation pour les données …  Lire la suite

Aulls, Mark (Supervisor)  Lire la suite

I investigated oribatid mite assemblages in a beech-maple forest in southwestern Quebec. I first examined the effects of four forest stand types (American Beech (Fagus grandifolia) dominated, Sugar Maple (Acer saccharum) dominated, mixed deciduous and coniferous plantations) and three open site types (agricultural field, fallow pasture and unmanaged hay field) in structuring oribatid mite assemblages. My second study focused on the effects of changes in litter depth (a factor that varies by stand type) on the structure of oribatid assemblages. Stand type was shown to be an important factor in determining oribatid mite abundances, species richness and assemblage composition. Results …  Lire la suite

Reversible phosphorylation is a major mechanism for regulating the activity, localization and stability of proteins required for vital cellular processes such as glucose metabolism, gene expression, establishment of polarity, mitosis and cytokinesis. Phospho-regulation is driven by the activities of kinases and phosphatases. Together, these enzymes account for ~3% of eukaryotic genomes and it is estimated that 30% of the eukaryotic proteome is composed of phospho-proteins. Protein kinases (PKs) have been studied extensively, however relatively little is known regarding the signaling networks of protein phosphatases (PPases). The identification of PPase functional networks has been slow due to the redundant nature of …  Lire la suite

Designing systems with the ability to make optimal decisions under uncertainty is one of the goals of artificial intelligence. However, in many applications the design of optimal planners is complicated due to imprecise inputs and uncertain outputs resulting from stochastic dynamics. Partially Observable Markov Decision Processes (POMDPs) provide a rich mathematical framework to model these kinds of problems. However, the high computational demand of solution methods for POMDPs is a drawback for applying them in practice. In this thesis, we present a two-fold approach for improving the tractability of POMDP planning. First, we focus on designing good heuristics for POMDP …  Lire la suite

The perirhinal cortex (PRC) and the lateral entorhinal cortex (LEC) are essential components of the medial temporal lobe memory system, but the functional organization and interconnectivity of these structures is poorly defined. In this thesis, novel in-vitro and in-vivo approaches were developed to investigate the synaptic organization, intrinsic properties and cholinergic modulation of neurons in the PRC and LEC. In-vivo and in-vitro field potential profiles, combined with current-source density analysis and in-vitro intracellular recordings, demonstrated the existence of bi-directional excitatory synaptic interactions between the PRC and the LEC. Intracellular recordings and dye injection were also used to perform a morphological …  Lire la suite

This master's thesis is written by an indigenous person who sees education as a healing process. In the tradition of narrative inquiry (Clandinin and Connelly, 2000) I interweave autobiographical texts with reflections on colonialism, indigeneity and multiculturalism. I am Amazigh (Kabyle) from the country now called Algeria, where my people have lived for some 5,000 years. I was raised in France, where I experienced a racism which I became conscious of when I arrived in Canada. I draw on the Medicine Wheel teachings given by First Nations Elders in Canada as the philosophical framework of my text, a framework based …  Lire la suite

Despite its enduring popularity in performance circles, Carl Nielsen's Wind Quintet, op. 43 (1922), has received little attention from the scholarly community. This thesis provides the most comprehensive examination of the work to date and includes original analyses of each of the three movements. Moreover, it illuminates and defines stylistic trademarks that are found not only in this piece, but also within Nielsen's oeuvre more broadly. These traits include the weakening of tonal design, the liberal use of chromatic harmonies, contrapuntal writing, and the allusion to and distortion of traditional forms. This thesis highlights Nielsen's synthesis of traditional and idiosyncratic …  Lire la suite

Web-based social networks have become one of the most popular applications on the Internet in recent years. However, most of the social networks rely on some simplistic trust models to manage trust information of the users, which can cause problems ranging from unsatisfied user experience to exposure to malicious users. This thesis proposes a gravity-based trust model to enhance the aggregation of personal trust information into a subjective reputation system. This new model maps all users on the social network into n-dimensional Euclidean spaces based on their direct trust information, and creates a trust social neighborhood for each user. The …  Lire la suite

This thesis studies the dynamics of two-dimensional cantilevered flexible plates subjected to axial flow and proposes a new energy-harvesting concept, the flutter-mill, utilizing the flutter motions to generate electrical power. The nonlinear model of the cantilevered flexible plate is developed using the inextensibility assumption. The panel method, in particular the unsteady lumped vortex model associated with a dynamic vortical wake, is used for calculating the aero/hydro-dynamic loads acting on the plate. The investigation of the dynamics of this system is conducted systematically in the multiparameter space involved, in order to give a comprehensive picture of the global dynamics of the …  Lire la suite

The vast majority of secondary school English teachers in China are non-native English speakers (NNS). These teachers might not have adequate language proficiency to promote a communicative language environment for students. This has raised an ongoing discussion concerning the growing need to foster NNS teachers' communicative language proficiency, which has been identified as one of the most important qualifications for successful ESL/EFL (English as a Second Language/English as a Foreign Language) teachers (Murdoch, 1994; Kamhi-Stein & Lee, 1999; Nunan, 2003). In this study, 53 secondary NNS teachers from Chinese secondary schools were asked to self-assess their English proficiency as well …  Lire la suite

Parallel optical interconnects (POI) have attracted a great deal of attention in the past two decades as the system bandwidth continues to increase. Optical interconnects are known to have more advantages than their electrical counterparts in many aspects such as crosstalk, bandwidth distance product, power consumption, and RC time delay. The parallelization of several optical links is also an effective method to increase the aggregate data rate while keeping the component count manageable and to reduce the unit cost of optics, electronics, and packaging at lower line rate. Parallel optical transceiver modules running at several gigabits per second are commercially …  Lire la suite

Efficient muscle regeneration is essential in mammals in order to overcome daily stress such as wounds, exercise and pathologic processes. This regeneration relies on muscle stem cells, the satellite cells. After a lesion, satellite cells are activated, proliferate and differentiate in fonctionnal muscle fibers. Our laboratory has previously shown that the transcription factor GATA-6 is expressed in the satellite cells. The present thesis confirms the expression of this factor in this cell type. Also, it seems that GATA-6 could be implicated in the maintaining of quiescence of these cells. The GATA-6 heterozygous mouse muscle is characterized by an increase level …  Lire la suite

This thesis offers an analysis of the intertextual practices in Marie-Claire Blais's trilogy Soifs by which we explore the way the author integrates into her novels significant literary figures and texts in order to underline one of the trilogy's constant themes: the innocence and suffering of the victims of the twentieth century and of today. In this fiction saturated with literary and artistic references, literature appears as a standpoint on modern world and works are considered to be acts of creation that opposes to the "choeur de la destruction" the voices of writers and artists.  Lire la suite

This thesis is an examination of Mulla Hadi Sabzawari's commentary (1797--1878 or 1881) on the Mathnawi of Jalal al-Din Rumi (d. 1273), entitled Sharh&dotbelow;-i Asrar-i Mathnawi. The purpose of this study is to analyze Sabzawari's approach and investigate how this synthesizer of the philosophy of Mulla S&dotbelow;adra and Suhrawardi interprets Rumi's message. Moreover, I will assess the details of his arguments and philosophical interpretations of Rumi's verses. Chapter one is a brief introduction to Rumi's biography and his works as well as a review of the commentary tradition on his Mathnawi. In chapter two a full account of Sabzawari's life, …  Lire la suite

SRY (Sex determining Region of Y chromosome) is the master gene initiating testis determination in mammals. To shed light on the molecular mechanism of SRY action during testicular differentiation, we examined the effects of TAT-HMG fusion protein on gonadal sex differentiation in culture. HMG is the DNA binding motif of SRY and "TAT" is a protein transduction domain. Each pair of CD1 mouse gonadal primordia at 11.5 days post coitum (dpc) was cultured with or without TAT-HMG dissolved in dimethyl sulfoxide (DMSO) up to 3 days. Immunocytochemical labeling and Real-time RT-PCR of Sry, Sox9 and Mis indicated that DMSO blocked …  Lire la suite

1,25-dihydroxyvitamin D3 (1,25D3), also know as cholecalciferol, is still best known as a regulator of calcium homeostasis. However more recent studies have revealed the pleiotropic actions of 1,25D 3, including immune and nervous system modulation, and cellular proliferation and differentiation. Epidemiological and model studies have revealed the anticancer properties of 1,25D3, which modulates gene transcription through the nuclear vitamin D receptor (VDR). This dissertation is composed of four different studies that focus on the molecular and genetic events that underlie the anticancer properties of 1,25D3. Our first set of experiments was a genome-wide exploration of cognate 1,25D3 response elements (VDREs), …  Lire la suite

Aluminum-silicon-copper cast alloys of the 319-type have attained a commercially important status because of their widespread use. Artificial aging treatments are routinely applied to these alloys in order to obtain precipitation hardening and improve their mechanical properties. Standard treatments may not always yield the optimum achievable properties, thus Mg and Sr are commonly added to improve the response of the alloy to aging and to modify the eutectic Si morphology from acicular to fibrous, respectively. The present study was carried out to investigate aging behavior of four 319-type alloys in regard to such mechanical properties as their ultimate tensile strength, …  Lire la suite

Objective. To examine the profile of executive function (EF) performance in children diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) as function of their subtypes and comorbid disorders. Methods. Two hundred and eighteen, 6-12 year old children clinically diagnosed with ADHD were characterised according to their clinical profile. Various EF domains were assessed while children were not on medication. General cognitive performance was assessed using Wechsler Intelligence Scale for Children. Results. 54.1% of children were diagnosed with combined subtype, 34.9% with inattentive subtype and 11% with hyperactive subtype. Significant age difference was found in ADHD subtype distribution and significant age and …  Lire la suite

Severe anemia is the most prevalent life-threatening complication of malaria infection. In addition to destruction of red blood cells (RBC), decreased RBC production or erythropoietic suppression has been shown to contribute to malarial anemia. The mechanism of this suppression is unknown, but it is considered to be multifactorial since erythropoietic suppression can be observed in the presence of both inflammatory mediators and parasite-derived factors. Experiments presented in this thesis aimed at determining the role of host cytokines released in response to blood-stage malaria infection and parasite-derived factors in erythropoietic suppression underlying the development of malarial anemia. Pro-inflammatory cytokines released during …  Lire la suite