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Memoires du passe au ceri. Trois generations de Cakkiliyars temoignent (Tamil Nadu - Inde)
No full textThis PhD research focuses on untouchables’ (Dalits) perceptions of their past and more specifically on the transformations that occurred at the inter-caste level. For that sake, more than 60 testimonies have been collected. The investigations have been centered around three generations of people in two communities of the cakkiliyar caste in Tamil Nadu (South India). Firstly, the following main questions have been addressed : How did these cakkiliyar communities drift from one state to another in the lapse of 40 years? How did the inter-caste relationships evolve? Which were the main triggering factors and their consequences? What was the impact on people’s minds and mentalities? At the micro level and with the help of oral testimonies, this work endeavors to highlight the past of these communities and to ‘un-knit’ the social, political, cultural and economic changes that 'made the difference' at the local level with reference to the dalit/non-dalit relationship. A strong difference of dynamics emerges from the study of the two villages, it is largely highlighted throughout the work. Secondly, memory issues are investigated. Interestingly, although Dalits share a common past, they bear witness in many different ways. People’s mindset today largely influences the perspective each one adopts while speaking about the past. Three main prototypes defining the different postures can be observed in cakkiliyar oral testimonies: a) the prototype of “Dalits” looking for their dignity, b) the hesitant “Cakkiliyars” and, c) the submissive “Harijans”. Each of these prototypes implies a certain mindset, a specific behavior, some specific aspirations for the future and a certain posture towards the past and history: from strong dissent and expression of agency to resignation and bemoaning their fate, from volubility to silence, from interest to detachment.Cette recherche doctorale étudie les perceptions qu'ont les intouchables (Dalits) de leur passé, et plus spécifiquement des transformations survenues dans les rapports intercastes. A cette fin, plus de 60 témoignages ont été récoltés. Les investigations ont été menées dans deux villages de montagne du Tamil Nadu (Inde du sud) auprès de trois générations de gens appartenant à la caste des Cakkiliyars. Nous nous sommes, tout d'abord, posée les questions suivantes: comment ces communautés cakkiliyars sont-elles passées d'une condition à une autre - bien différente - en l'espace de 40 ans? Comment les rapports intercastes ont-ils évolués? Quels ont été les principaux facteurs déclencheurs, et quelles furent leurs conséquences? Quel fut leur impact sur l'état d'esprit et les mentalités des gens? Par une approche favorisant l'étude au niveau micro et avec l'aide des témoignages oraux, nous avons cherché à remettre à jour le passé de ces communautés et à dénouer l'écheveau des changements tant sociaux, politiques, culturels ou économiques qui ont "fait la différence" au niveau local en ce qui concerne les rapports intercastes. Les deux villages présentent des dynamiques propres; nous nous sommes efforcée de mettre les différences en évidence. Ensuite, et enfin, la question de la mémoire a été abordée de front. Nous avons découvert que, bien que les Dalits partagent un passé commun, ils en témoignent de manières très variées. L'état d'esprit actuel des témoins influence grandement la perspective adoptée par chacun pour parler du passé. Nous avons, par conséquent, défini trois prototypes principaux qui caractérisent les différentes postures que l'on a pu observer dans les témoignages: a) le prototype des "Dalits" en quête de dignité, b) les "Cakkiliyars" indécis et, c) les "Harijans" soumis. Chacun de ces prototypes implique un certain état d'esprit, un comportement spécifique, des aspirations bien précises pour le futur ainsi qu'un certain positionnement par rapport au passé et à l'histoire: du désaccord marqué et de l'envie d'agir à la résignation et à la lamentation quant à son destin, de la volubilité au silence, de l'intérêt au détachement.(DOCFILO02) -- FUNDP, 201
Language Labels, Language Practices. A multiple case study of parents with children enrolled in Dutch-medium education in Brussels
No full textIn this dissertation, we looked into the language practices and language-related representations (or labels) of parents from different (linguistic) backgrounds in multilingual Brussels. Applying a social rather than linguistic approach to bilingualism, we conducted semi-directed interviews and collected spoken data from five couples, which were analyzed through a critical discourse analytic approach. The main aims of the study were threefold: (1) to investigate how the parents themselves relate to a number of common sociolinguistic labels used in policymaking, research and general discourse on language and identity in Brussels; (2) to look into the language practices these parents engage in and the ways in which these practices resonate with the labels used; (3) to examine whether and how having a child in Dutch-medium education in Brussels both informs these parents’ language practices and the way they describe themselves.(DOCFILO01) -- FUNDP, 201
A NAD dependent glutamate dehydrogenase coordinates metabolism with cell division in Caulobacter crescentus
No full textCell division is a key process to ensure survival, development and spreading of all livings. Cell division must be coordinated with other cellular processes such as chromosome replication or growth but also according to nutrient supplies i.e. metabolism. How bacteria control cytokinesis in function of metabolic availability remains poorly understood. In bacteria, the earliest event of cell division is the positioning of the tubulin-like GTPase FtsZ at the future site of division. There, FtsZ assembles into a polymeric and dynamic structure, the Z-ring thanks to GTP binding and lateral interaction between FtsZ filaments. At the division site, the Z-ring served as a scaffold for all of the cell division proteins and has been proposed to drive the constriction process. Due to its central role in cytokinesis, FtsZ is a prime target for the regulation of cell division. Here, we identified a NAD(H)-dependent glutamate dehydrogenase (GDH) that controls Z-ring disassembly coupling cell division with cellular growth in the α–proteobacterium Caulobacter crescentus. GDH catalyzes the interconversion of glutamate into NH4+ and α-ketoglutarate, thereby linking nitrogen and Krebs cycles. We found that GdhZ (for glutamate dehydrogenase interacting with FtsZ) directly stimulates the GTPase activity of FtsZ in vitro, leading to protofilaments shrinkage, only when GdhZ was enzymatically active. Absence of GdhZ strongly delays cytokinesis in C. crescentus and leads to various cell division defects. GdhZ co-localizes with FtsZ in late predivisional cells and GdhZ abundance varies during the cell cycle being specifically degraded during DNA replication the period during which the Z-ring is assembled at the division site in C. crescentus. Altogether these results prompt us to propose a model where GdhZ stimulates Z-ring disassembly in predivisional cells allowing daughter cells release with sufficient nutrient supplies to ensure survival. The high observed Km of GdhZ for glutamate suggests that active GdhZ could provide a plenty signal to the division apparatus. Interestingly, deletion of gdhZ homolog in the facultative intracellular pathogen Brucella abortus (gdhZba) leads to cell division defects, similarly to Caulobacter ∆gdhZ. Moreover, it impairs proper intracellular replication of Brucella during infection of macrophages, strongly suggesting that the catabolic activity of GdhZba is required for a successful infection. In addition, we found that during cytokinesis GdhZ activity is coordinated with the cell division regulator KidO. KidO is a putative oxidoreductase whose cell division control relies on its NAD(H)-binding ability. We showed that, in vitro, KidO inhibits lateral interactions between FtsZ-protofilaments (bundles) only in presence of NADH. Interestingly GdhZ and KidO are similarly regulated along the cell cycle of C. crescentus. In vitro, addition of KidO enhances GdhZ stimulatory effect on the GTPase activity of FtsZ, which lead us to propose that GdhZ and KidO act synergistically to stimulate depolymerization of the Z-ring, KidO dissociating FtsZ bundles and GdhZ stimulating GTPase activity of newly available FtsZ protofilaments. Altogether this work illustrates how C. crescentus can adjust cell cycle parameters according to nutrient availability fluctuations.(DOCSC03) -- UNamur, 201
Automatic Test Generation for Data-Driven Applications
No full textAll human beings make mistakes. Programmers are human beings. Thus programmers make mistakes. This seemingly harmless syllogism can have disastrous consequences for the society. As larger parts of our economic and social life rely on computers, software bugs caused by programming mistakes do pose an increasing thread. An example which has left its mark in people's minds is the Ariane 5 rocket explosion in flight, due to an integer overflow in the onboard computer. In current software engineering practice, testing is the primary approach to locate programming mistakes. Before going into production, software is thus tested in a set of real scenarios, in order to detect the bugs at best. Nevertheless, the concrete process enabling software testing in practice is complex, repetitive and costly. This is why researchers and industrialists have been working to automate it for long. The idea is notably that the computer helps the programmer to select automatically the most relevant test scenarios. An interesting technique to do so is symbolic execution, today in use at Nasa and Microsoft. Technically, given a code unit to test, symbolic execution enables the computer to generate test values for the input parameters, making it possible to cover a representative set of execution paths in the code. The present work introduces an extension for symbolic execution, enabling one to use this approach in a new context: testing transactional and data-oriented code units. This kind of code units, frequent in practice, is characterized by a brief and targeted interaction with a relational database, storing large amounts of information in a structured way. Finding bugs in such a kind of code unit is critical, as it can avoid corrupting possibly very important data. In order to achieve this, our work goes back to the theoretical foundations of relational databases and proposes a relational symbolic execution mechanism for SQL. This enables generating automatically input data, including some valid content for the database, making it possible to test the considered code unit with an adequate coverage. The proposed extension is implemented within a tool and evaluated over code samples mixing Java and SQL statements. Our approach is compared with related work. A set of research directions to make it usable at a larger scale are identified and discussed.(DOCSC06) -- UNamur, 201
Elaboration de revêtements à base de tantale et de nanotubes de carbone sur titane et Nitinol : vers de nouvelles plateformes pour biomatériaux osseux
No full textEvery year, several million people worldwide must appeal to orthopedic surgery to repair osseous defects due to diseases or traumatic events. Corresponding medical needs are in constant evolution, as well for implant durability (depending of patient’s age, morphology…) as for therapeutic efficiency (reduction of immune risks – allergies, carcinogenic effets…). Scientific research related to the design and optimization of platform (bio)materials for bone substitutes takes thus on crucial importance. In this context, the present work specifically focus on the reinforcement of surface properties of metallic platforms based on titanium and Nitinol (nickel-titanium alloy), whose biochemical and mechanical characteristics (biocompatibility, corrosion resistance, density, strength, shape memory effect and superelasticity for Nitinol) are particularly interesting for further uses in orthopedic medicine. Different approaches are considered to this end in order to consolidate the barrier effect at the material-host interface and to improve the bioactive capacities for inducing and guiding the osseous (re)growth after implantation: sol-gel and electrochemical deposition of thin tantalum oxide coatings, molecular self-assembly of multifunctional organophosphonic acids, and incorporation of chemically-modified carbon nanotubes. The main goal of this study aims at the in-depth investigation of the phenomena underlying the exploited surface treatments. It also intends to highlight their direct consequences in terms of films composition and morphology, as well as their protective and functional abilities. This will be undertaken through spectroscopic (XPS, EDX), microscopic (SEM, TEM, AFM) and electrochemical (CV, LSV, SECM) characterizations.Chaque année, plusieurs millions de personnes à travers le monde doivent recourir à la pose d’un implant orthopédique afin de remédier à un défaut osseux causé par une maladie ou un événement traumatique. Les besoins médicaux en la matière sont donc en constante évolution, tant sur le plan de la durabilité (en fonction du profil du patient – âge, morphologie, …) que de l’efficacité thérapeutique (diminution des risques de rejet immunitaire – allergies, effets cancérigènes, …). La recherche scientifique liée à la conception et à l’optimisation de (bio)matériaux plateformes pour substituts osseux revêt dès lors une importance cruciale. Dans ce contexte, le présent travail considère spécifiquement le renforcement des propriétés de surface de plateformes métalliques à base de titane et de Nitinol (alliage nickel-titane), dont les caractéristiques biochimiques et mécaniques (biocompatibilité, résistance à la corrosion, densité, solidité, mémoire de forme et superélasticité pour le Nitinol) sont particulièrement intéressantes pour une exploitation ultérieure en médecine orthopédique. Différentes approches sont envisagées à cette fin pour consolider l’effet barrière à l’interface matériau-hôte et en vue d’améliorer le caractère bioactif afin d’induire et de guider la repousse osseuse après implantation : on aura ainsi recours aux dépôts sol-gel et électrochimiques de minces revêtements d’oxyde de tantale, à l’auto-assemblage moléculaire d’acides organophosphoniques multifonctionnels, et à l’incorporation de nanotubes de carbone chimiquement modifiés. L’objectif de cette étude vise à comprendre de manière approfondie les phénomènes sous-tendant les différents protocoles de modification de surface ainsi qu’à mettre en évidence leurs conséquences en termes de composition, de morphologie, de protection et de fonctionnalité des films générés. Ceci sera réalisé par le biais de caractérisations à la fois spectroscopiques (XPS, EDX), microscopiques (MEB, MET, AFM) et électrochimiques (CV, courbes de polarisation, SECM).(DOCSC02) -- UNamur, 201
Dynamique des satellites d'Uranus
No full textUranus and its complex and unexpected system of moons are still today a mystery of the solar system. This thesis focuses on the dynamics of these natural satellites, and discusses their orbital and internal evolutions, in the future as in the past. These motions are strongly perturbed by the orbital mean motion resonances; in particular, the 3:1 resonance is present at several places in the Uranian system and is one of the keys to understand its complexity. In this work, a model of resonance (truncated and averaged) is proposed, based on the restricted 3-body problem; it is compared with a numerical full N-body model. Those models are applied to the satellites Cressida and Desdemona, both close to the 3:1 resonance with Miranda. Coupled with the tidal and oblateness effects, they propose, for the first time, a dynamical scenario for the two satellites, in agreement with the present observations. The same resonance appears between the huge moons Miranda and Umbriel; Miranda is characterized by a surprising high inclination, explained by several authors in the nineties, by a past temporary capture in a secondary resonance. The results of this thesis, based on recent methods of chaos detection, numerical integration and frequency analysis, have confirmed, nuanced and completed this explanation. Again for Miranda, an innovative interdisciplinary approach is developed, which couples the orbital and thermal evolutions and gives promising results.(DOCSC00) -- FUNDP, 201
Salut de l’âme et mémoire du corps Typologie et iconographie du mémorial médiéval dans l’ancien diocèse de Liège
No full textxLes monuments funéraires du Moyen âge répondent à des thèmes qui reflètent les conceptions sur la mort, la mémoire et la survie. Le thème qui prédomine est celui du salut de l’âme, auquel répond l’image de l’homme transfiguré par la vision de la béatitude. La thèse propose la découverte d’un thème où la survie de l’homme est évoquée par la perpétuation de la vie, offrant, principalement via les images du lignage, une conception d’une mémoire du corps. La méthode de l’exposé, qui porte sur 650 monuments de l’ancien diocèse de Liège, propose une analyse détaillée de la typologie du mémorial médiéval.(DOCSC05) -- UNamur, 201
Study of the transcriptional responses to the inhibition of the expression of the mitochondrial genome: analysis of the activation of the mitochondrial unfolded protein response and the integrated stress response.
No full textMitochondria are multifunctional organelles and their continued maintenance is required for cell homeostasis and function. Upon organelle dysfunction, a mitochondrial-to-nucleus communication, known as retrograde signalling, triggers an orchestrated expression of nuclear genes to relieve the stress and/or compensate the defect. The importance of the good working of these stress response pathways can be highlighted by the various pathophysiological developments associated with their impairment. The activation of two stress responsive pathways, known as the mitochondrial unfolded protein response (mtUPR) and the integrated stress response (ISR), was assessed upon various stresses such as the inhibition of the mitochondrial DNA (mtDNA) expression. While there is no induction of mtUPR-related gene markers HSPD1 (heat shock 60kDa protein 1) and ClpP (caseinolytic mitochondrial matrix peptidase proteolytic subunit), the transcription factor CHOP-10 (C/EBP homologous protein-10) was systematically overexpressed when mtDNA expression is inhibited. Furthermore, increased expression of this transcription factor correlates with induction of three genes associated with ISR activation: HERP (homocysteine-inducible, endoplasmic reticulum stress-inducible, ubiquitin-like domain member 1), ATF3 (activating transcription factor 3) and Trib3 (tribbles pseudokinase 3). These results were confirmed in three cancer cell lines (HeLa, Hep3B, MCF-7) as well as in primary human hepatocytes. In addition, the requirement of the ISR key transcription factor ATF4 (activating transcription factor 4) for CHOP-10 induction was demonstrated as well as the involvement of the GCN2 (General control non-derepressible kinase 2) kinase in the phosphorylation of eIF2α. Altogether, these data demonstrate that a GCN2-eIF2α-ATF4-CHOP-10 axis is activated in response to mitochondrial dysfunction. The decrease in cytosolic translation that occurs consequently to eIF2α phosphorylation could help to reduce the mitochondrial stress.(DOCSC03) -- UNamur, 201
Étude de la formation et des propriétés dynamiques, conformationelles et énergétiques d'assemblages supramoléculaires à base de nanotubes organiques et d'agrégats d'argent dans des brins d'ADN
No full textThe subject of our theoretically oriented Ph. D. thesis focuses on two types of supramolecular assemblies combining organic and inorganic materials: the first concerns complexes of organic molecules of various sizes and tubules formed by macrocycles, the second being a polynucleotide matrix allowing the formation of clusters of a few metallic atoms. In the first case, host molecules are cyclodextrins (CDs) assembled in tubules. The latter can accommodate various types of guest organic molecules, but more specifically, in the scope of our work, diphenylpolyenes (DPPs), styrene monomers, as well as a polystyrene oligomer. In the second case, the subject systems are polynucleotide strands complexing silver atoms, in the ionic, and then neutral state. The general goal of our work consists in the elucidation of structural, energetic, and dynamic properties of those complexes, with the help of theoretical methods based on “classical” force fields. Regarding the first system of interest, we used the MMFF94 force field (FF), that we introduced ourselves in the Tinker simulation software source code. We first studied the organisation of CD tubules by three schemes: a structural examination of geometries from the Cambridge Structural Database, simulated annealing studies to evaluate the stability of tubular arrangements, and an incremental construction procedure of the tubules by molecular dynamics (MD). For β-CDs, the investigations pointed to a head-to-head configuration, while γ-CDs favoured a head-to-head+tail-to-head triplet. The position and interactions of water molecules inside the obtained tubular arrangements were studied as well. Various complexes for DPPs (DPB, DPH, and DPO) included in the β- and γ-CDs tubules were considered and compared based on structural, energetic, and dynamic criteria. Destabilisations of the arrangements are reported for perpendicular orientations of the DPPs and for the most heavily loaded tubules. Regarding assemblies between γ-CD and the two longest DPPs, various arrangements show similar stability. The same type of analyses was performed for the inclusion of styrene and polystyrene in the β- and γ-CDs tubules. These allowed us to correct assumptions formulated by experimentalists regarding the in situ polymerisation of styrene. We next studied chromophore systems made of silver clusters stabilised by polynucleotide strands. To do so, classical interaction potentials relative to silver, neutral and cationic, were introduced in the AMBER FF. MD simulations allowed analysing the nature and force of the interactions between the various parts of the nucleic oligomers and the silver clusters, through averages of interaction energies. Conformational analyses were necessary to explore the flexibility of the supramolecular assemblies, specifically by radial distribution functions and Ramachandran-type maps.Le sujet de notre thèse, à orientation théorique, se focalise sur deux types d’assemblages supramoléculaires combinant matériaux organiques et inorganiques : l’un concerne des complexes formés de molécules organiques de tailles variables et de tubes composés par des macrocycles, l’autre étant une matrice de polynucléotide permettant la formation d’agrégats de quelques atomes métalliques. Dans le premier cas, les molécules hôtes sont des cyclodextrines assemblées en tubules. Ces derniers peuvent accueillir différents types de molécules organiques, mais plus spécifiquement, dans le cadre de notre travail, des diphénylpolyènes (DPPs), des monomères de styrène, ainsi qu’un oligomère de polystyrène. Dans le deuxième cas, il s’agit de chaînes de polynucléotide complexant des atomes d’argent, à l’état ionique, puis neutre. L’objectif général de notre travail consiste en l’élucidation des propriétés structurales, énergétiques et dynamiques de ces complexes, à l’aide de méthodes théoriques basés sur des champs de forces dits classiques. Concernant le premier système d’intérêt, nous avons utilisé le champ de forces (FF) MMFF94, que nous avons introduit nous-mêmes dans le code source du programme de simulation Tinker. Nous avons d’abord étudié l’organisation des tubules de CDs par trois méthodes différentes : un examen structural des géométries issues de la Cambridge Structural Database, des études en recuit simulé pour évaluer la stabilité des arrangements tubulaires, et une procédure de construction incrémentale des tubules par dynamique moléculaire (DM). Pour les β-CDs, les investigations ont abouti à une configuration tête-à-tête, tandis que les γ-CDs favorisent un triplet tête-à-tête+queue-à-tête. La position et les interactions des molécules d’eau à l’intérieur des arrangements tubulaires obtenus ont été également étudiées. Différents complexes de DPPs (DPB, DPH et DPO) inclus dans les tubules de β- et γ-CDs ont été considérés et comparés sur base de critères structuraux, énergétiques et dynamiques. Des déstabilisations des arrangements ont été observées pour les orientations perpendiculaires des DPPs et pour les tubules les plus fortement occupés. Concernant les assemblages entre la γ-CD et les deux plus longs DPPs, plusieurs arrangements présentent une stabilité similaire. Le même type d’analyses a été appliqué pour l’inclusion du styrène et du polystyrène dans les tubules de β- et γ-CDs. Celles-ci nous ont permis de corriger des hypothèses formulées par des expérimentateurs concernant la polymérisation in situ du styrène. Nous avons ensuite étudié des systèmes chromophores composés d’agrégats d’argent stabilisés par des brins de polynucléotide. À cette fin, des potentiels d’interaction classiques relatifs à l’argent, neutre et cationique, ont été introduits dans le FF AMBER. Des simulations en DM ont permis d’analyser la nature et la force des interactions entre les différentes parties des oligomères nucléiques et les agrégats d’argent, à travers des moyennes d’énergies d’interaction. Des analyses conformationelles ont été nécessaires afin d’explorer la flexibilité des assemblages supramoléculaires, plus particulièrement des fonctions de distribution radiale et des cartes de type Ramachandran.(DOCSC02) -- FUNDP, 201
Sustaining the quality of Web services
No full textWithin the framework of Service Oriented Architecture, we introduce a new framework in order to better sustain the quality of Web services. The framework groups similar Web services together. Our contributions include mechanisms on both the micro-management and macro-management of a group of Web services in order to better sustain the quality of Web services. Finally we demonstrate the effectiveness of the mechanisms through experiments using some real-world values.(DOCSC06) -- FUNDP, 201