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See detailIdentification et caractérisation de bactériocines produites par deux bactéries lactiques (Enterococcus faecium CWBI-B1430 et Enterococcus mundtii CWBI-B1431) isolées à partir de fromages frais artisanaux péruviens
Aguilar Galvez, Ana Consuelo ULg

Doctoral thesis (2011)

A screening of lactic acid bacteria (LAB) with bacteriocin-like inhibitory activity against Listeria monocytogenes was performed. The screening was conducted in 27 traditional artisanal-produced cheeses ... [more ▼]

A screening of lactic acid bacteria (LAB) with bacteriocin-like inhibitory activity against Listeria monocytogenes was performed. The screening was conducted in 27 traditional artisanal-produced cheeses obtained from different Peruvian regions. Two thousand two hundred and seventy seven strains (2277) were isolated, of which 20 exhibited bacteriocin-like inhibitory activity, two strains stand out for having higher activity against listeria, as well as stability at pH value of 2-11 and a thermal stability. The two strains were identified using 16 S ribosomal DNA method, and were registered in the GenBank database of NCBI (National Center for Biotechnology Information). These were Enterococcus faecium CWBI-B1430 (accession number EF591817) and Enterococcus mundtii CWBI-B1431 (accession number EF591816). Two of the major factors concerned in a potential health risk associated with the genus Enterococcus were evaluated, and it was demonstrated that they were sensitive to vancomycin and showed no hemolytic activity. Genetic studies showed the presence of four putative bacteriocin genes in both strains, these were enterocin A, enterocin B, enterocin P, and mundticin KS. The reverse transcription-PCR analysis was realized, the expression of the bacteriocin genes enterocin A, enterocin B, and mundticin KS in CWBI-B1430 was showed, while bacteriocin genes enterocin P and mundticin KS was demonstrated in CWBI-B1431. These results are the first report of the expression of mundticin KS in E. faecium and enterocin P in E. mundtii. Also, the expression was studied at different temperatures, unlike the enterocin P, where only a positive signal was obtained at 12 and 37°C. All other enterocin showed positive signal at 12, 30, 37 and 42°C. The production of bacteriocins on a small scale, in both strains was studied. It was investigate the influence of initial pH (4.5, 5.0, 5.5, 6.0, 6.5 and 7.0), temperature (25, 30 and 37°C) and oxygen level (anaerobic, microaerobic and aerobic). The conditions for maximizing the production of bacteriocins are : initial pH of 7.0, at 37 °C, and microaerobic conditions for CWBI-B1430 strain; initial pH of 6.5, at 37 °C, and an aerobic condition for CWBI-B1431. The influence of the source of carbon and nitrogen, as well as their concentration in the bacteriocin production, was studied. The study of the production of short-chain fatty acids by these strains of multiproducing bacteriocins, showed the propionic acid as the most important. The purification study confirmed that the two bacteria in question are multi-producing of bacteriocins, as shown by the obtained chromatograms, showing different molecular weights, different charge and hydrophobicity level. The results of in situ application of the two selected strains or their supernatant does not show the same efficiency as those obtained in vitro. Factors such as temperature and food composition may be the origin of these results. Therefore, we propose the use of both strains in the food industry, for being multi-producing bacteriocins, have broad spectrum of inhibition and because the substances that produce have functional properties that are useful in the food industry. [less ▲]

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See detailTHE ROLE OF CUSTOMER PERCEIVED EMPLOYEE EMOTIONAL COMPETENCE IN SERVICE ENCOUNTERS
Delcourt, Cécile ULg

Doctoral thesis (2011)

The present dissertation is based on three studies, sharing one common theme: employee emotional competence (EEC). The overall aim of this dissertation is to examine the effect of customer perceptions of ... [more ▼]

The present dissertation is based on three studies, sharing one common theme: employee emotional competence (EEC). The overall aim of this dissertation is to examine the effect of customer perceptions of employee emotional competence on their evaluations of critical service encounters. To achieve this goal, each study builds a theoretical framework and presents empirical assessments of aspects of the issue under consideration. While psychology scholars have conceptualized, measured, and evaluated the impact of EEC in work-related relationships (i.e., internal perspective of EEC), the role of EEC in customer-related relationships (i.e., service encounters) has received little attention by marketing scholars. We argue in this dissertation that a customer perspective of EEC is necessary to examine EEC in such context. Recent studies in the service literature have suggested that EEC could be valuable in service encounters–especially in critical service encounters since customers want employees to recognize the uniqueness of their personal experience (Price et al., 1995b). Given the potential influential role of EEC in a marketing context, researchers have called for further investigation (Kidwell et al., 2011; Verbeke et al., 2008). Therefore, this dissertation approaches the concept of EEC by first focusing on emotional competence (i.e., the actual demonstration of emotionally competent behaviors by the employee) instead of emotional intelligence (i.e., the potential one employee has to demonstrate emotionally competent behaviors). In this respect, we examine customer perceptions–rather than employee perceptions or supervisor perceptions of EEC–since these last measures are subject to important biases and since only customers can evaluate if the employee has actually displayed emotionally competent behaviors during the service encounter. More specifically, the focus is on the exploration of EEC and its effects on customer outcomes. Based on a review of the literature from various disciplines and research streams, comprehensive models are constructed, summarizing theoretical propositions and hypotheses. The first study examines in a field study the impact of customer perceptions of EEC on customer satisfaction and loyalty in high-contact services. The mediating role of rapport is examined. We found that EEC influence both customer satisfaction and loyalty. Rapport mediates both relationships. The second study aims to conceptualize EEC in service encounters and to develop a short, valid, and reliable measure based on that conceptualization. By using a rigorous scale development procedure, we define EEC as customer perceptions of employees’ abilities to perceive, understand, and regulate customer emotions in a service encounter to ensure harmonious encounters. This measure of EEC is strongly related to key customer outcomes such as customer satisfaction. The third study aims to understand in an experimental design the role of EEC compared to employee technical competence (ETC) in emotionally charged service encounters. We found that EEC moderates the relationship between ETC and customer outcomes such as negative customer emotions, rapport, and service encounter satisfaction. When EEC is low, the impact of ETC on those variables is low or even non significant. When EEC is high, ETC strongly influences those customer outcomes. Together, the three studies provide rich insights on the impact of EEC on customer outcomes in a service encounter context. To improve the customer’s experience in service encounters, managers should encourage their contact employees to display emotionally competent behaviors by perceiving, understanding, and regulating customer emotions. When employees have high EEC, the impact of ETC on customers is the highest. Rapport mediates the relationship between EEC and key customer outcomes such as customer satisfaction and loyalty. [less ▲]

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See detailEntre Union européenne et Région wallonne : multiplicité des échelons de pouvoir et subsidiarité territoriale Analyse de la subsidiarité territoriale au travers des directives Seveso, IPPC, responsabilité environnementale et de leurs mesures de transposition en Région wallonne.
Hanson, Sophie ULg

Doctoral thesis (2011)

La Région wallonne s’inscrit dans un contexte organisationnel particulier. D’une part, elle constitue une composante d’un État membre de l’Union européenne. D’autre part, elle fait partie d’un État à ... [more ▼]

La Région wallonne s’inscrit dans un contexte organisationnel particulier. D’une part, elle constitue une composante d’un État membre de l’Union européenne. D’autre part, elle fait partie d’un État à structure fédérale comportant une entité fédérale, des entités fédérées et des collectivités locales (provinces, communes). Il est permis de s'interroger, dans ce contexte, sur la nature des relations que peut entretenir la Région wallonne avec les entités gravitant autour d’elle. Le principe de subsidiarité, dans sa fonction territoriale, peut constituer une clé de lecture dans la mesure où il est indissociable des systèmes institutionnels multi-niveaux. Il implique que ce soit l’échelon qui est le plus proche des citoyens qui soit privilégié afin de remplir une tâche. Si toutefois, il ne parvient pas à rencontrer un objectif déterminé, l’échelon supérieur peut intervenir s’il peut satisfaire ce dernier de manière plus efficace. La question centrale qui a guidé la recherche a donc été de savoir, au travers de l’exemple de la Région wallonne, si les rapports entre les échelons de pouvoir, de la commune à l’Union européenne s’effectuent en application du principe de subsidiarité, dans sa fonction territoriale. Trois directives européennes importantes ressortissant au domaine de l'environnement (Seveso, IPPC et responsabilité environnementale) ainsi que leurs mesures de transposition en Région wallonne ont été examinées à l'aune de ce principe. [less ▲]

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See detailDes projets aux réseaux: la construction d'un compromis
Vandenborne, Emilie ULg

Doctoral thesis (2011)

Cette thèse étudie la construction en réseaux des projets. Elle a pour objet une sociologie de l’action en réseaux appuyée d’une sociologie des normes et d’une sociologie de l’acteur-réseau. Elle ... [more ▼]

Cette thèse étudie la construction en réseaux des projets. Elle a pour objet une sociologie de l’action en réseaux appuyée d’une sociologie des normes et d’une sociologie de l’acteur-réseau. Elle interroge les comportements collectifs autour de projets au sein du secteur biotechnologique. La question centrale qui se pose est celle de l’apparition de nouvelles formes de gouvernance réticulaire à partir d’une configuration par projets. [less ▲]

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See detailConception et synthèse de nouveaux complexes de ruthénium pour la formation catalytique de liaisons C–C
Borguet, Yannick ULg

Doctoral thesis (2011)

During the last decade, catalytic methods enabling the formation of single and multiple C–C bonds have sparked a major interest from the Chemists community. Among them, olefin metathesis has emerged as a ... [more ▼]

During the last decade, catalytic methods enabling the formation of single and multiple C–C bonds have sparked a major interest from the Chemists community. Among them, olefin metathesis has emerged as a powerful tool, opening unique routes to synthesize organic compounds and polymers. This is mainly due to the advent of well-defined ruthenium–benzylidene complexes first developed by Grubbs and co-workers in the early 1990’s. Since then, countless structural alterations have been made to these archetypal compounds in order to tailor their activity, stability, solubility, . . . However, the synthesis of these derivatives may be tedious and costly since it almost systematically requires the use of the Grubbs 1st generation catalyst as a starting material. Therefore, non-proprietary catalysts with high activity are still eagerly sought. This thesis is mainly focused on the design of straightforward and reliable syntheses of new complexes derived from the homobimetallic molecular scaffold (I) first reported by Severin in 2005. Our first aim was to enhance the catalytic activity of such compounds in olefin metathesis and in controlled radical reactions. [less ▲]

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See detailRôle des moustiques Culicidae, de leurs communautés microbiennes et des réservoirs vertébrés, dans la transmission des arbovirus à Madagascar
Raharimalala, Fara Nantenaina ULg

Doctoral thesis (2011)

These last ten years, Indian Ocean islands have been the theatre of severe epidemics of arboviroses. However, little information was available about the local dynamics of the virus transmission and ... [more ▼]

These last ten years, Indian Ocean islands have been the theatre of severe epidemics of arboviroses. However, little information was available about the local dynamics of the virus transmission and identity of the vector species and vertebrates réservoirs involved. Madagascar island was chosen for its high endemic biodiversity, contrasting climatic conditions and drastic changes in habitats due to an increase anthropic pressure. These factors increase the epidemiological risks of infectious diseases. In this context, our objective was to characterize the role of Culicidae as major vectors, the associated microbial communities, and wild vertebrates (lémurs) as potential réservoirs in the transmission arboviroses. Molecular techniques allowed udpdating the biogeography of Aedes and showed the dominance of Aedes albopictus competent to chikungunya virus. Other mosquitoes captured belonged to Culex antennatus, Culex decens, Culex quinquefasciatus et Mansonia uniformis. The bacterium Wolbachia was detected in most mosquito especies,but Culex antennatus. Searching of arboviruses by qRT‐PCR revealed infection of Culex antennatus and lemurs (Lepilemur edwardsi et Eulemur rufus) by the rift valley fever virus. [less ▲]

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See detailContribution to the epidemiology of bovine tuberculosis in northern Ecuador
Proaño Perez, Freddy ULg

Doctoral thesis (2011)

See attached document, page vii

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See detailImpact des facteurs de contexte sur le design des systèmes de contrôle de gestion dans les collectivités locales béninoises: Une approche contingente
Togodo Azon, Degodo Aimé ULg

Doctoral thesis (2011)

Très peu d’études empiriques ont analysé les facteurs qui influencent le design des systèmes de contrôle de gestion dans les collectivités locales de l’Afrique au Sud du Sahara. La présente recherche, qui ... [more ▼]

Très peu d’études empiriques ont analysé les facteurs qui influencent le design des systèmes de contrôle de gestion dans les collectivités locales de l’Afrique au Sud du Sahara. La présente recherche, qui prend pour cadre le Bénin, explore les facteurs qui influencent le design des systèmes de contrôle de gestion dans les communes béninoises. Pour ce faire, nous avons développé six chapitres complémentaires articulés en trois parties. Dans une première partie, nous avons fait un état de la littérature qui aboutit à un modèle conceptuel. Ce modèle présente les différents outils de contrôle de gestion et les facteurs organisationnels et extra-organisationnels susceptibles d’influencer le choix des outils. La deuxième partie est une étude empirique hypothético-déductive à base de questionnaires sur soixante-dix communes béninoises. Dans cette partie, nous avons présenté les caractéristiques des systèmes de contrôle de gestion utilisés dans les communes béninoises et identifié les facteurs institutionnels et socioculturels qui influencent la configuration organisationnelle et le design des systèmes de contrôle de gestion dans les collectivités locales béninoises. La troisième partie est une étude empirique inductive qui présente trois études de cas. Ces études de cas, utilisées en complément et en approfondissement de l’analyse quantitative, ont révélé le rôle capital que joue le style de management adopté par les autorités locales dans la gestion du changement organisationnel et dans la maitrise des pressions politiques locales. Enfin, la recherche s’achève en dégageant les principales implications de notre modélisation sur l’introduction de la Nouvelle Gestion Publique en Afrique sub-saharienne et sur le type de décentralisation choisi par le Bénin. [less ▲]

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See detailGénétique de la neuropathie laryngée récurrente chez le cheval
Dupuis, Marie-Capucine ULg

Doctoral thesis (2011)

Recurrent laryngeal neuropathy (RLN), known as « roaring » or « whistling », has been considered as the most important equine airway disease of the horse. It can cause abnormal respiratory noise during ... [more ▼]

Recurrent laryngeal neuropathy (RLN), known as « roaring » or « whistling », has been considered as the most important equine airway disease of the horse. It can cause abnormal respiratory noise during fast exercise, secondary to a reduced abduction of the left arytenoid cartilage, which may impair performance. Despite significant research into the disease, some aspects, such as etiology and pathogenesis, remain unknown. Several papers suggest a genetic basis but molecular studies have never been reported. Using the EquineSNP50 Beadchip, we genotyped 234 cases (196 Warmbloods, 20 Trotters, 14 Thoroughbreds and 4 Draft Horses), 228 breed-matched controls and 69 parents. Linkage disequilibrium and population structure were quantified before performing single marker and haplotype-based association studies, as well as family-based linkage analyses. Two genome-wide suggestive loci were identified on chromosomes 21 and 31, driven by the enrichment of a “protective” haplotype in controls compared to cases. Our study indicates that predisposition to RLN has a complex determinism, probably involving a high number of genes, of which the candidates on chromosome 21 and 31 may have the largest effects. We performed a copy-number variants analysis on the same data. After characterization of the regions harbouring these variants, an association study with RLN was conducted. A duplication on chromosome 10 was identified in ten affected horses and two unphenotyped parents that were sharing a long haplotype. This work provides novel insights in the genetic determinism of NLR and opens new field of research. If the genuine nature of these loci is confirmed in independent cohorts, identifying the causative genes may increase our understanding of RLN pathogenesis. Assuming that RLN is very polygenic, predictive diagnosis and selection may be more effective using a genomic selection type of approach. [less ▲]

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See detailEtudes sur le syntagme nominal en néo-égyptien: l'article zéro, la possession attributive et le changement de genre
Néven, Laurence ULg

Doctoral thesis (2011)

Le syntagme nominal offre de nombreuses possibilités de recherches. Les études peuvent se concentrer sur des syntagmes nominaux simples ou complexes et s’intéresser aux différents éléments qui les ... [more ▼]

Le syntagme nominal offre de nombreuses possibilités de recherches. Les études peuvent se concentrer sur des syntagmes nominaux simples ou complexes et s’intéresser aux différents éléments qui les composent. De même, les relations syntaxiques entre deux ou plusieurs syntagmes nominaux peuvent faire l’objet d’une attention particulière et les recherches peuvent se focaliser sur une langue ou un état de langue spécifique, ou, au contraire, s’envisager dans une perspective typologique prenant en compte un nombre plus ou moins élevé de langues. Dans le cadre de ma thèse de doctorat, j’ai décidé de me concentrer sur le néo-égyptien et d’étudier trois points essentiels qui sont la détermination, la possession et le genre. Le premier chapitre de ce travail s’est intéressé à la détermination des substantifs et plus particulièrement aux articles. L’originalité de cette partie réside dans le fait de proposer et de montrer l’existence d’un article zéro qui peut être intégré au paradigme des articles. Celui-ci se distingue dès lors d’une absence d’article. L’opposition entre ces deux concepts repose sur certains critères fondamentaux. Il faut ainsi que le syntagme nominal précédé de zéro puisse commuter avec un syntagme nominal précédé d’un article défini et/ou indéfini. Il doit également se trouver dans un environnement syntaxique similaire et offrir à l’ensemble une signification particulière. J’ai constaté qu’il existait des alternances entre l’article défini, indéfini et zéro (apposition, générique et vocatif). Si ce n’est dans le cas du générique, l’usage d’un zéro n’est pas significatif. J’ai également étudié l’emploi des déterminants au sein de certaines constructions spécifiques et de catégories de noms (abstraits, collectifs, comptables, de fonction, massifs et propres). Seuls les noms abstraits, comptables et massifs font usage d’un zéro significatif. L’article défini sert à spécifier l’entité ou à référer à une entité connue à la fois du locuteur et de l’interlocuteur. L’article indéfini réfère également à une entité particulière, mais spécifique ou non. Enfin, l’article zéro est utilisé lorsque l’on veut référer à une entité homogène et dénote une non-quantification absolue. L’opposition à deux membres, c’est-à-dire entre l’article défini et zéro s’est révélée pertinente dans le cas des noms abstraits et des noms comptables ; et l’opposition à trois membres, c’est-à-dire entre l’article défini, l’article indéfini et zéro s’est révélée pertinente avec les noms massifs. Il semble donc que la présence d’un article zéro soit principalement liée à certaines catégories de substantifs et ne réponde pas à des critères syntaxiques selon sa présence dans telle ou telle construction. L’objectif de mon chapitre II était d’offrir une classification des divers procédés permettant d’exprimer la possession attributive en néo-égyptien. L’examen de ces moyens formels s’est réalisé en se fondant sur trois points principaux : l’environnement syntaxique et sémantique, l’influence du genre littéraire et/ou du registre de texte et l’évolution diachronique. L’opposition entre l’article possessif et le pronom suffixe est principalement une opposition de registre textuel, mais elle peut également être d’ordre syntaxique ou sémantique. L’opposition entre l’article possessif et le pronom indépendant concerne la définition des possédés. Le pronom indépendant est employé lorsque le substantif est indéfini ou précédé du démonstratif. La préposition m-di prendra le relais du pronom indépendant dans l’expression de la possession attributive, mais les prémices de ce remplacement fonctionnel ne sont pas perceptibles avant la fin de la 20e dynastie. En revanche, l’opposition entre le génitif direct et le génitif indirect est quasi inexistante. En effet, le génitif direct n’est guère plus productif et se limite pour la majeure partie aux titres de fonctions. L’objectif de mon dernier chapitre était de montrer qu’ont existé en égyptien ancien des changements ou des variations de genre. Cette étude ne pouvait se prétendre exhaustive en regard du corpus délimité. J’ai donc voulu poser les premiers jalons et proposer des hypothèses qui expliqueraient certains de ces changements ou de ces flottements. En me fondant principalement sur la contribution de Michel Roché, concernant les variations du genre en langue française, j’ai établi cinq schémas prenant en compte les différentes possibilités. Les principaux arguments qui m’ont été utiles pour l’analyse du genre sont les articles ou leurs substituts et l’accord du pseudo-participe et du pronom de rappel (pronom suffixe). Cela m’a permis de mettre en exergue plusieurs mots qui ont connu un flottement dans l’attribution du genre avec un retour au genre originel (principalement des parties du corps), ainsi que des substantifs qui ont changé de genre entre le néo-égyptien et le démotique (AH.t et btA). Le mot dmi « ville », quant à lui, correspond peut-être à un dédoublement de genre dans lequel le nouveau lexème dmi.t se spécifie sémantiquement. Enfin, l’emprunt de mots sémitiques a également provoqué des confusions dans le genre des noms et plus spécifiquement parmi les substantifs qui originellement se terminent par un –t appartenant au radical. J’ai proposé plusieurs hypothèses pour expliquer ces changements ou flottements de genre. Il s’agit de l’absence ou la rareté du déterminant, des changements phonétiques, de la proximité formelle et sémantique de deux substantifs et de l’emprunt à des langues étrangères. [less ▲]

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See detailStudii privind perfectionarea managementului strategic in dezvoltarea rurala durabila din Depresiunea Jijia-Bahlui
Paveliuc Olariu, Codrin ULg

Doctoral thesis (2011)

This paper addresses one of the most current and important problem of the Romanian rural space, whose study is absolutely necessary for the uniformous performance of the different types of socio-economic ... [more ▼]

This paper addresses one of the most current and important problem of the Romanian rural space, whose study is absolutely necessary for the uniformous performance of the different types of socio-economic activities at rural communities level, namely sustainable rural development. The motivation behind this PhD thesis is constituted by the relevance of the scientific and practical importance of the role that a formal proces of strategic management in sustainable rural development holds at rural communities level both from their development options point of view and, also, in its whole. Extremely important for the strategic management of sustainable rural development are the analysis of the linkages that exist between rural communities and urban centres and their evaluation because, through this areas` specificity, both constitute environments that can easily influence development at individual and society level in case a way of harnessing them doesn`t exist. Thus, the implementation of the strategic management concept becomes necessary whose role is to manage and evaluate the previously mentioned phenomenon. From this point of view, strategic management can be defined as a set of rigurously established and organized activities which, starting from local existing conditions, analyze the needs and development potential of the rural community in a development vision in view of filtering and minimizing the negative effect of rural-urban linkages. By choosing the “Studies regarding the improvement of strategic management in sustainable rural development in the Jijia-Bahlui Depression” theme I followed to highlight a problem by understanding which you can explain the causes of the socio-economic success or failure of rural communities. Choosing the research team regarding strategic management in sustainable rural development can be justified through the ever growing interest manifested at public level through the development of rural space and rural development support policies. The main principle of the PhD thesis is constituted by offering a conceptual framework for analyzing and identifying the needs and the development potential of rura l communities that are the basis of the strategic process. The key words of the paper are: strategy, rural, urban, rurbanization, rural-urban lonkages, strategic management, development, rural space, rural environment, rurality, quality of life, community, inhabitant, decision, decision making process, decision factor, needs, potential. Synthesis of the main parts in the PhD thesis First part, „BIBLIOGRAPHIC STUDY REGARDING SUSTAINABLE RURAL DEVELOPMENT OF LOCAL COMMUNITIES” consists of 2 chapters that hold theoretical aspects regarding sustainable rural development, rurbanization, quality of life and strategic management. Part II, „OWN RESEARCHED, RESULTS AND THEIR INTERPRETATION” is composed of 6 chapters that underline own ressearches carried out along side the results and their interpretations. The first chapter of the PhD thesis „STUDIES REGARDING THE SUSTAINABLE RURAL DEVELOPMENT CONCEPT” is an introductory, explicatory one, realizing a general analysis of the basic concepts specific to the sustainable rural development process in local communities. In its evolution, chapter I presents a few theoretical aspects regarding the dimesions of sustainable rural development, also observing the functions and interdependencies that arrise at its level. Also, the first chapter refers to the evolution and state of knowledge regarding quality of life. The quality of life analysis in this cahpte starts from presenting the concept in different forms, then continuing with its manifestations under the form of the poverty concept. Also, the quality of life indicators utilized at world level are presented, a plurality of approached being noticed not just in regards to concept, but also from the phenomenon practicality point of view. CHAPTER II – „RESEARCH REGARDING LOCAL ENVIRONMENT INFLUENCES ON THE SUSTAINABLE RURAL DEVELOPMENT PROCESS” defines the idea that, at local community level, there are influences of the internal and external environment on the socio - economic development on individual and society level. Harnessing these influences through adopting some strategies by the local public administration in this sense assmues the indetification and their evaluation with great accuracy and, in their support comes strategic management which becomes an indispensable guide for management critical situations in the local socio-economic development. The importance of this chapte derives from the fact that strategic management, as an essential tool in local public administration, holds as a purpose to streamline the local development process in order to realize the set objectives with maximum efficiency. Strategic management implies the establishment by local public authorities of the vision that is willing to assume and, also, concrete establishing of the strategic development objectives following a deep analysis of locally existing needs,and,also, of the individual and society potential. Also, rurbanization has been defined, beed identified key decision factors at local level, with a focus on public institutions representatives with a role in developing and implementing public policies. CHAPTER III „PURPOSE, OBJECTIVES AND RESEARCH METHOD” reveals the main scientific purpose of the paper. The needs and development potential of rural communities and, also, or rural-urban interactions evaluation constitutes the main scientific purpose of the paper. the main objective of the thesis is represented by the identification and evaluation and, also, of interactions that exist between rural communities and urban centres and adopting the adequate measures to adapt these to the specific of the local community. The specific objective of the paper resides in applying the strategic management process in sustainable rural development at the Belcesti commune level through the prism of the two components: analysis on the basis of the needs and development potential of the rural community and strategic management through rural-urban linkages and rural-rural flows. Overcoming the answers formulation difficulties assumes adopting decisions to the resources allocation method, optimizing local development strategies and, also, the ways of attracting at local level the positive rural-urban and rural-rural flows. CHAPTER IV, named „THE ANALYSIS OF THE BELCESTI COMMUNE LOCAL ENVIRONMENT” presents a few aspects regarding the definition of the Jijia-Bahlui Depression rural environment, natural resources, human resources, economic resources, local economy, performances, risks and recent accomplishments of agriculture and, also, the agriculture market of Belcesti commune. In this chapter the research area has been delimited, the analysis being oriented towards studying the way in which strategic management is done at local level, the main problems of local development, respectively infrastructure development, cultura and social cohesion. CHAPTER V – „ANALZA NEVOILOR ŞI POTENŢIALULUI DE DEZVOLTARE A COMUNEI BELCEŞTI, JUDEŢUL IAŞI” is dedicated to the case study done in Belcesti commune, Iasi county. Belcesti commune corespunde to the demands regarding a complex and rigurous approach as constituted by the present paper. The paper offers the theoretical-methodological framework necessary to the scientific and operational substantiation of the strategic management at commune level. The reasoning that substantiated this approach needed, on one side, the conceptual identification of the necessary methodology for evaluating the needs and development potential at local community level in five areas of activity proven of special importance for Belcesti commune. The principle that stands at the basis of the Belcesti commune development is the continuous improvement of the local environment through the growth of the administrative capacity of the local public authorities, these trying to give citizens trust in the decision making process. This chapter is dedicated to the evaluation of the needs and development potential of the community through the working groups methods as a response to the risk associated to the existing development discrepancies at this time in the North-East Development Region. The general local development strategies that presently exist in Romanian communes depend on the criterias used. Depending on the frequency and impact of the utilized analysis you can choose as response measures between prevention, avoidance and decisions transfer. A sustainable rural development process must constitute a major component of any decision making process having an important role in accomplishing foreseen at its initiation. The presented indicators have a relative common evolution tendency, the interactions between areas of activitities and their areas of expertise being major influence factor. CHAPTER VI – „THE ANALYSIS OF RURAL-URBAN LINKAGES AND OF THE RURBANIZATION EFFECT ON THE SOCIO-ECONOMIC DEVELOPMENT OF THE LOCAL COMMUNITY – BELCESTI COMMUNE, IASI COUNTY” presents the importance of evaluating the existing rural-urban linkage between rural communities and neighboring urban centers. These interactions present at local communities’ level influence both the individual and society in general, their impact being analyzed through different methods. The isolation degree of a locality is the most direct way to evaluate it, the peripherality index and the distance-time one revealing the type of access to different types of services at local level and, also, the level of interaction between the analyzed commune and the surrounding localities. In the case of Belcesti commune, the peripherality index has a value of 1.15 with a low to average degree of interaction with surrounding cities, respectively Harlau and Podu Iloaiei, being instead affected from an access to services point of view as the distance-time index analysis shows us. CHAPTER VII – „SCENARIOS FOR THE SUSTAINABLE RURAL DEVELOPMENT OF THE LOCA COMMUNITY – BELCESTI COMMUNE, IASI COUNTY” summarizes the results of the realized analysis, conceiving, according to some prognosis of the effect of the evolution in three directions of the peripherality and distance-time indexes, 3 development scenarios for Belcesti commune. The existence of such a prognosis reveals the fact that, due to a well substantiated analysis, different development visions of the rural community can be realized. In the realistic scenario, this vision present the implication framework of local public authorities in the diversification and growth of the local economy by supporting entrepreneurial initiatives of different types, key areas being agriculture and tourism. These scenarios were substantiated on the basis of opinions survey done on citizens and public institutions representatives, their opinions regarding the development visions of Belcesti commune being able to influence decisively its direction. CAPITOLUL VIII – „CONCLUSIONS AND RECOMMENDATIONS” resumes the hyphoteses from which we started, underlining own interpretations and their importance at rural community level. The end of the paper is constituted in a set of conclusiond regarding the impact of the strategic management process in sustainable rural development, the evolution of some socio - economic indicators, as a result of its action in the rural space and, also, the manifestation of different components of this (individual, decision group, society, public environment, private environment etc.) to the influence of rural-urban linkages. The conclusions set out the personal contribution to solutioning problems generated by the sustainable rural development process and, indirectly, by rural-urban linkages, resorting to their utilization through filtering and recirculation in a positive manner. BIBLIOGRAPHY – is composed from a number of 79 titles from the national and international literature and, also, from Internet research. [less ▲]

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See detailSEISMICALLY RETROFITTING AND UPGRADING RC-MRF BY USING EXPANDED METAL PANELS
Phung Ngoc, Dung ULg

Doctoral thesis (2011)

Reinforced concrete moment resisting frames (RC-MRFs) have been widely used as the main structural resisting systems for over 30 years based on their capacity in resisting both gravity loads and lateral ... [more ▼]

Reinforced concrete moment resisting frames (RC-MRFs) have been widely used as the main structural resisting systems for over 30 years based on their capacity in resisting both gravity loads and lateral forces like winds or earthquakes and on low cost of construction. However, there have been still many existing RC-MRFs not designed according to any modern seismic code. This may lead to some undesired failures under a rather low intensity earthquake. There are several existing retrofitting systems available for seismically retrofitting RC-MRFs, such as steel braces, steel plate or RC shear walls, base isolators…In those, some are able to increase the stiffness, strength, deformation and energy absorbing capacity of the structures and some are able to reduce the influence of the seismic actions on the structure. Despite having advantage in increasing the stiffness and strength for the buildings, the use of bulky systems like RC shear walls to retrofit buildings under seismic actions becomes more limited due to its complication in erection and high costs for foundation. The use of lighter retrofitting systems such as steel braces or shear walls made from steel or aluminium… has been becoming more favourable. Made from sheet steel or various alloys by cutting and simultaneous stretching cold, expanded metal is considered as a macro-foam material. An expanded metal panel (EMP) with rectangular dimensions of 1.25m x 2.5m having many rhomb shape stitches with different geometrical sizes is the popular product. Currently it is employed primarily in the areas of protection (fencing, gates) and architecture. The final goal of this study is to consider a new application different in the field of civil engineering and more specifically that of the earthquake resistance of buildings. The work plan includes two main parts. This first part will set the EMP over existing techniques and see if its use is justified in the context of earthquake resistance. In addition, a more detailed description of the EMP is considered. In this way, the different data required for modelling the new resistance system are known and analyzes, tests and comparisons can be made in order to validate the use of EMP in the context of earthquake resistance. A complete study on pure shear behaviour of EMP under monotonic and quasi-static cyclic loading has been developed including experimental, theoretical and numerical investigations. To apply EMP in seismically retrofitting RC-MRFs, thirty two RC-MRFs have been designed according to two codes EC2 and EC8. The seismic performance of the studied frames has been evaluated using Pushover and NLTH analyses. For the frames designed according to EC2 or EC8 with low ductility, some prominent deficiencies are found, such as incomplete load path or the soft-story failure. Based on the knowledge of deficiencies of the existing frames, many attempts to exploit EMP to seismically retrofit the existing frames have been made. All frames designed according to EC2 and EC8 with Low Ductility Class need to retrofit because they cannot reach the target displacements due to premature failure of beam-column joints. To seismically retrofit them by using EMP, a design procedure based on Direct Displacement Based Design (DDBD) has been proposed. The design is an iterative procedure, starting with the selection of the target displacements at the top based on the results from Pushover analysis. They are usually less than the limit displacements at which RC frames collapse due to crushing of the concrete at beam-column joints. These displacements are also the target ones for the retrofitted frames. The results from design procedure proposed are significantly affected by some typical factors such as selected target displacements and capacity of the existing frames contributing to overall resistance of the retrofitted frames, equivalent viscous damping of the EMP and MRFs as well as geometrical dimensions of the existing frames. The retrofitted design results, assessed by Pushover and NLTH analyses, have indicated that DDDB is a useful tool to design EMP to seismically retrofit the existing frames. With EMP, all retrofitted frames can reach target displacements under design earthquakes without any brittle failure, not like the original frames. However, EMP cannot improve the behaviour of the beam-column joints. Under the earthquakes greater than design ones, failure of the nodes is still observed in all retrofitted frames. The comparison of the seismic performance of the frames before and after being retrofitted has shown that EMP is able to reduce the influence of the earthquake on the original frames by increasing their strength and stiffness and by absorbing the seismic energy. Proposed design procedure of connection between EMP and the frame elements is applicable. This was verified in the experiments when connecting EMP with the steel testing frames. The design approach for the connection is based on Capacity Design, all starting with the maximum resistance of the bars in a rhomb-shape stitch of the EMP and the tension field action developed in the EMP during shear loading. However, it is necessary to perform tests on the connections between EMP and the RC beams and columns. Also, improved practical details can be developed. [less ▲]

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See detailContribution to Entanglement Theory, Applications in Atomic Systems and Cavity QED
Gillet, Jérémie ULg

Doctoral thesis (2011)

We introduce in this thesis two entanglement detection criteria, the Schrödinger-Robertson partial transpose inequality, which can be implemented experimentally in a variety of systems and generalized N ... [more ▼]

We introduce in this thesis two entanglement detection criteria, the Schrödinger-Robertson partial transpose inequality, which can be implemented experimentally in a variety of systems and generalized N-qubit concurrences, which can be used to evaluate multipartite entanglement in N-qubit mixed states. Then, we investigate ways to experimentally produce entanglement by giving a theoretical model which successfully describes the dipole blockade effect. We study its possible applications in systems of two and three two-level atoms as well as its relations with the EITeffect in systems of two three-level atoms. Finally, we show the possibility of two-photon processes in a system of two two-level atoms embedded in a cavity by using perturbation theory and a full master equation approach. We unveil interesting features of blockade and transparency in such cavity QED systems. [less ▲]

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See detailImplication des cellules Natural Killer (NK) dans le développement des lésions associées à l'infection par les papillomavirus humains (HPV)
Renoux, Virginie ULg

Doctoral thesis (2011)

Persistent infections with high-risk papillomavirus (HPV) are associated with more than 25% of cancers induced by infectious agents. Nevertheless, the two vaccines preventing HPV infection have no ... [more ▼]

Persistent infections with high-risk papillomavirus (HPV) are associated with more than 25% of cancers induced by infectious agents. Nevertheless, the two vaccines preventing HPV infection have no therapeutic efficacy and it has been estimated that there will be no measurable decline of HPV-associated tumours before 2040. The immune system is able to control, at least partially, HPV infection and subsequent tumour development. Around 90% of HPV-infected women will clear the virus within two years, but the immune effectors responsible for this viral clearance are unknown. Hence, the aim of this study was to determine if Natural Killer (NK) cells could play a role in the immune response against HPV infection and related cancers. The first part of this work was focused on the in vitro interaction of NK cells with L1 and L1L2 Virus Like Particles (VLP) of HPV16. We observed that, in the presence of HPV-VLP, NK cells displayed a higher cytotoxic activity against HPV+ cells by increasing the exocytosis of their cytotoxic granules and by secreting TNF-α and IFN-γ. NK cell activation was correlated with a fast entry of HPV-VLP by macropinocytosis and we determined that cell surface CD16 expression was necessary for HPV internalization, but also for degranulation and cytokine production. In the second part, to understand the molecular mechanisms of HPV-VLP stimulation, we investigated the signalling pathways operating in NK cells to trigger their cytotoxic activity in the presence of viral particles. We observed that the MAP kinases ERK and p38 were phosphorylated in the presence of both L1 and L1L2 HPV-VLP. Using specific inhibitors, we demonstrated that phosphorylation of these MAPK was required for degranulation and cytokine secretion by NK cells in the presence of VLP. In conclusion, NK cell activity could be an important player in the immune response contributing to viral clearance and to regression of HPV-induced cervical lesions. [less ▲]

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See detailModélisation spatialement distribuée et physiquement basée d’écoulements hydrologiques et hydrodynamiques pour l’aide à la gestion d’ouvrages hydrauliques
Khuat Duy, Bruno ULg

Doctoral thesis (2011)

La gestion des ressources en eau constitue une préoccupation qui prend une place de plus en plus importante dans nos sociétés. Les événements climatiques extrêmes subis ces dernières années (pluies ... [more ▼]

La gestion des ressources en eau constitue une préoccupation qui prend une place de plus en plus importante dans nos sociétés. Les événements climatiques extrêmes subis ces dernières années (pluies diluviennes mais également sécheresses) montrent toute la nécessité d’une meilleure compréhension des phénomènes en cause afin de mettre en place une gestion efficace des ressources. Ces études passent notamment par le développement de logiciels de simulation basés sur des modèles hydrologiques et hydrodynamiques fiables capables de représenter correctement les phénomènes réels mis en jeu. Cette thèse contribue à la mise en place d’un outil de modélisation spatialement distribuée et physiquement basée d’écoulements hydrologiques et hydrodynamiques, destiné notamment à fournir une aide précieuse pour la gestion d’ouvrages hydrauliques. Chaque composante de modélisation du circuit hydrologique, depuis la pluie jusqu’à l’exutoire de la rivière, est examinée. Des améliorations ou développements plus fondamentaux sont alors proposés pour améliorer la qualité de modélisation. Entre autres, cette thèse aborde en profondeur des sujets tels que la prise en compte de la microtopographie dans la représentation des phénomènes de surface (stockage dans les dépressions, écoulement en ruisselets, relations hauteurs-section-volume…), le calcul de l’infiltration (modèle à fronts multiples, effet de l’occupation du sol…) ou l’écoulement dans la couche hypodermique (écoulement saturé/non saturé, mise en pression…). Les recherches et développements portent également sur l’écoulement dans les axes de concentration (création d’un réseau de rivières cohérent à la fois avec le modèle numérique de terrain et les levés précis sur site, exploitation adéquate des données de section, modélisation efficace des ouvrages en charge ou non…). La modélisation des surfaces imperméables (avec séparation des zones égouttées ou non) est également abordée de façon détaillée, dans le cadre d’une application sur un bassin versant instrumenté de 130 km². Cette application envisage aussi bien la modélisation d’un événement ponctuel que des simulations à long terme. Enfin, l’étude d’un bassin peu instrumenté permet de montrer la large applicabilité et sa capacité à servir de support efficace dans la gestion des rivières et des ouvrages hydrauliques associés. [less ▲]

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See detailMathematical modeling of biogeochemical processes associated to a coccolithophorid (Emiliania huxleyi) bloom - Study of the seasonal and long-term variability of biogeochemical properties in the Black Sea using a Data Interpolating Variational Analysis (DIVA)
Joassin, Pascal ULg

Doctoral thesis (2011)

A OD biogeochemical model has been developed to represent coccolithophorid physiological features concerned by carbon export (primary production, active DOC excretion, TEP formation, and calcification ... [more ▼]

A OD biogeochemical model has been developed to represent coccolithophorid physiological features concerned by carbon export (primary production, active DOC excretion, TEP formation, and calcification) and susceptible to be sensitive to varying pCO2. The model is initially calibrated and validated using a large set of biogeochemical data monitored during Emiliania huxleyi blooms induced in a mesocosm experiment, under present-day pCO2 conditions. Afterwards, impacts of varying pCO2 conditions on Emiliania huxleyi physiology are investigated using biogeochemical variables monitored in mesocosms under low and high pCO2 conditions. The methodology promotes a double approach: the recalibration model parameters’ that optimizes the representation of observations from low and high pCO2 treatments, and the utilization of a RM ANOVA procedure to indicate significant differences between biogeochemical variables monitored during blooms induced in low and high pCO2 treatments. Since the early 1970’s, the Black Sea ecosystem has suffered significant ecological alterations, essentially caused by anthropogenic impacts. Dam constructions on the Danube River in combination with heavy nutrients discharge via the riverine run-off lead to strong modifications of its physical and biogeochemical properties, with final consequences consisting in an enhancement of the typical anoxic state of the deep waters. The long-term evolution of key biogeochemical variables (oxygen, hydrogen sulfide, and chlorophyll) has been studied through the reconstruction of horizontal fields, using long time data series and the DIVA interpolating tool. In addition, the examination during the best sampled period (1986-1993) of these biogeochemical variables’ fields, completed with nitrates and phosphates fields, highlighted seasonal and horizontal variability within typical sections of their profiles. [less ▲]

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See detailEtude comparée de l’écologie de deux espèces jumelles de Chiroptères (Mammalia : Chiroptera ) en Belgique: l’oreillard roux (Plecotus auritus) (Linn., 1758) et l’oreillard gris (Plecotus austriacus ) (Fischer, 1829).
Motte, Gregory ULg

Doctoral thesis (2011)

Introduction The purpose of this study is to verify one of the principal rules of ecology: the principle of exclusive competition, by using the sibling species of long-eared bats present in Belgium as a ... [more ▼]

Introduction The purpose of this study is to verify one of the principal rules of ecology: the principle of exclusive competition, by using the sibling species of long-eared bats present in Belgium as a model: the brown long-eared bat (Plecotus auritus) and the grey long-eared bat (Plecotus austriacus). Two similar species present in the same region and, what is more, share the same roost, must differ according to certain aspects of their ecological niche in order to be able to co-exist (MacNab 1971). In order to determine the resource sharing mechanisms between the two species, we have compared the three important dimensions of their ecological requirements: the use of trophic resources by means of faecal analysis and the use of space and time by radio-tracking. Trophic resources One hundred and thirty samples (4688 droppings, 6388 occurrences) taken from 5 single-species colonies of P. austriacus, 5 single-species colonies of P. auritus and from a mixed colony have been taken into account in the analysis of the summer diet. With the help of a first model constructed with the aid of generalized linear regressions, we have shown that, independently of the cohabitation conditions (single-species and mixed colonies), the two species have similar dietary requirements. Qualitatively, the same types of prey are consumed : Lepidoptera, Diptera (Craneflies, Cyclorrhapha and others Diptera), Coleoptera, Arachnids and Dermaptera. Small quantitative differences of between 3% to 8%, were seen to exist : P. austriacus consumes slightly more Coleoptera and Lepidoptera and fewer Craneflies than P. auritus. With the help of a second model enabling interspecific comparison of the diet according to whether the animal belonged to the single-species colonies or the mixed colony, we were able to show that the differences were more marked. When P. austriacus belong to single-species colonies, with reference to single-species colonies of P. auritus, predicted value indicate that they consume more Coleoptera (+ 5,0 %, p = 0,001) Lepidoptera (+ 14,4 %, p < 0,0005) and fewer Arachnids (- 8,3 %, p < 0,0005), Dermaptera (- 8,8%, p < 0,0005) and Craneflies (- 9,5 %, p = 0,009). This leads us to believe that the proportion of non-flying or diurnal prey gleaned by P. auritus is 2,5 times greater than that of P. austriacus. On the other hand, when P. austriacus belongs to the mixed colony, in reference to the P. austriacus single-species colonies, it changed its feeding behaviour. The predicted consumption of Arachnids and Dermaptera is higher, 14,5 % (p < 0,0005) and 11,3 % (p < 0,0005) respectively, while the consumption of Lepidoptera is much less (- 25,6 %, p < 0,0005). The syntopic P. austriacus also consume more craneflies (+ 7,9 %, p = 0,034) but fewer Coleoptera (-11,1 %, p = 0,009). This shows that P. austriacus posesses surprising adaptation abilities. The diet of the P. auritus of the mixed colony in relation to the single-species P. auritus, only showed slight variations on the other hand : - 7% (p = 0,006) for the Cyclorrhapha and - 4% (p = 0,002) for the Dermaptera. In syntopy, the study of seasonal variations has shown that the quantitative differences were significant at the end of gestation and lactation when the energy requirement is at its highest. In June, P. austriacus consumes more Arachnids (p = 0,046), in July, more Arachnids (p = 0,020) and fewer Lepidoptera (p = 0,020). In August, they consume more Dermaptera (p = 0.019), fewer Coleoptera (p = 0.032) and Lepidoptera (p = 0.034). Winter trophic ecology Our study has also led to the discovery of a little-known aspect of the ecology of chiroptera: winter trophic ecology. The results have shown that long-eared bats consume at least 70% of their prey which they capture by gleaning (Spiders, Dermaptera, Cyclorrhapha). These results have made it possible to confirm that the two species possess the ability to glean their prey. Spatial and temporal resources Twenty-two Plecotus were used for the analysis : seven P. auritus in Gozin, six P. austriacus in Gembes, five P. auritus and four P. austriacus in Pondrome (mixed colony). Eighty-four nights of monitoring corresponding to the discovery of 111 hunting grounds were used for the analyses. The results show that the use of space by P. auritus and P. austriacus contain similarities. The distance of the hunting grounds, the number of grounds visited per night, the duration of their use, their surface and the individual area of daily activity are similar. In the same way, contrary to what the literature suggests, it seems that P. auritus possesses the ability to exploit the open or semi-open areas like the meadows surrounded by linear woodland elements, while P. austriacus possesses the ability to exploit equally well the closed areas such as woods. In syntopy, the two species showed a different selection of habitats (grasslands, leafy woods,, gardens, edges for P. auritus and leafy or coniferous woods, gardens and edges for P. austriacus), P. auritus spending 64% of hunting time above the grassland against 83% in the woods for P. austriacus. On the other hand, in comparison with the two single-species colonies, the division of hunting time around the roost is more spread out in terms of space and the number of hunting grounds visited by night is more important. No difference in the exploitation of temporal resources was detected; the later departures from the Gozin colony were attributed to the presence of artificial lighting placed in front of the roost. The mechanisms allowing resources partitioning In the case of single-species colonies we have shown the existence of trophic resources partitioning. In fact, P. austriacus showed a diet less rich in Arachnids, Dermaptera, Craneflies and richer in Coeloptera and Lepidoptera than P. auritus. However, in syntopy, P. austriacus clearly modified its diet by consuming more Arachnids and Dermaptera to the detriment of Coleoptera and Lepidoptera. The consumption in Arachnids and Dermaptera remains higher than those of single-species P. auritus. Whether for single-species colonies or mixed colonies, trophic resources partitioning is quite evident. As requirements in terms of syntopy were modified, the results lead us to assume that inter-specific competition exists between this sibling species. The differences observed in the diet are probably dictated by a different use of the habitats. Indeed, in relation with the ecology of prey, the results of habitats use have made it possible to show that habitat partitioning occurs between the two species of long-eared bat. Our results therefore constitute a good illustration of the principle of competitive exclusion. Whether in the case of single-species colonies or mixed colonies, the two species share the trophic and spatial resources which allow them to co-exist. Recommendations for the conservation of the species To satisfy the requirements of the summer diet, it is necessary to maintain a network of diverse habitats composed of gardens, meadowlands, humid zones, hedges, bushes, tree alignments, leafy or mixed woodlands, preferably hygrophilous, allowing for the development of undergrowth and clearings. The results of the selection of surface habitats have globally confirmed the importance of these habitats used as hunting grounds. The selection of linear habitats such as tree-lines, hedges, bushes and edges also show the importance of ecological networks and the potentially damaging effects of the fragmentation of habitats on the bat population. In order to integrate the spatial requirements of P. austriacus, we recommend the establishment of a minimum protection perimeter of 3500 metres around the nest. With regard to P. auritus, it would be judicious to protect a minimum perimeter of a radius of 2000 metres. [less ▲]

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See detailOptimization Methods for the design and production of Naval Structures
Bay, Maud ULg

Doctoral thesis (2011)

In the past decades the marine industry has undergone significant evolution and the production of large passenger ships faced dramatic changes. The size, the complexity and the security standards of the ... [more ▼]

In the past decades the marine industry has undergone significant evolution and the production of large passenger ships faced dramatic changes. The size, the complexity and the security standards of the ships have increased and the ship-owners have become less and less willing to wait once the order is placed. In the meantime, due to growing intense competition, the shipyards have had to improve their efficiency and master their production costs: they progressively moved from manufacture to automated production processes. As a consequence, the shipyards have now to meet this difficult challenge: produce more complex ships, cheaper and faster. In the first part of the thesis we consider the structural optimization problem that arises in the early design phase of a project. Given a vessel overall dimensions and form, structural optimization consists in defining the scantling of the structure’s constitutive elements so as to minimize its total weight or cost, while taking weight, robustness and security issues into account. Designers have to make the most adequate choices within a very short period of time. The decisions made during the design phase have a major impact on the final structure and on its production cost. We propose new algorithms to compute near-optimal solutions of the discrete structural optimization problem. In the second part of the thesis, we turn to the building process of large ships and we present new methods to improve production facility management of shipyards. The ship building process requires the production and the assembly of tens, or even hundreds of thousands of steel elements. We define a space and time allocation problem that arises in assembly halls producing large building blocks and we develop algorithms for its solution. A successful implementation of a flexible and robust application is nowadays in use at a shipyard. [less ▲]

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See detailFinancement de l'entrepreneuriat rural dans la Région du Centre au Cameroun
Ahouissou, Brice Anicet ULg

Doctoral thesis (2011)

L’une des principales contraintes des micros entrepreneurs ruraux est l’absence de structures de financement adaptées susceptibles de favoriser leur accès au financement à moindre coût avec des conditions ... [more ▼]

L’une des principales contraintes des micros entrepreneurs ruraux est l’absence de structures de financement adaptées susceptibles de favoriser leur accès au financement à moindre coût avec des conditions moins contraignantes. Face à ce problème, il convient de se demander s’il n’est pas possible de développer des stratégies de financement adaptées aux micros entrepreneurs ruraux. C’est la réponse à cette question qui a servi de fil conducteur à ce travail. L’objectif global de la recherche est d’apporter une contribution à l’identification et à la réduction des principales contraintes auxquelles les entrepreneurs ruraux sont confrontés dans le financement de leurs activités. La méthodologie mise en œuvre s’est appuyée sur le suivi mensuel de 50 micros entrepreneurs pendant une année. Une enquête de validation a été organisée à la fin du suivi auprès de 141 micros entreprises, 19 usuriers et 21 Etablissements de microfinance (EMF). La mauvaise estimation des besoins de trésorerie, les taux d’intérêts élevés des crédits octroyés, les délais courts des remboursements, les faibles montants des emprunts sont les principales contraintes des micros entrepreneurs ruraux dans l’accès au financement mises en exergue dans cette recherche. Ces difficultés des micros entreprises sont, entre autres, dues à l’offre inadéquate des structures de financement formelles. En conclusion, il est proposé la mise en place d’un fonds de refinancement des EMF et la mise en œuvre d’un modèle de financement adapté à l’entrepreneuriat rural dans la région du Centre. [less ▲]

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See detailSustainable energy conversion through the use of Organic Rankine Cycles for waste heat recovery and solar applications
Quoilin, Sylvain ULg

Doctoral thesis (2011)

This thesis contributes to the knowledge and the characterization of small-scale Organic Rankine Cycles (ORC). It is based on experimental data, thermodynamic models and case studies. The experimental ... [more ▼]

This thesis contributes to the knowledge and the characterization of small-scale Organic Rankine Cycles (ORC). It is based on experimental data, thermodynamic models and case studies. The experimental studies include: 1. A prototype of small-scale waste heat recovery ORC using an open-drive oil-free scroll expander, declined in two successive versions with major improvements. 2. A prototype of hermetic scroll expander tested on vapor test rig designed for that purpose. The achieved performance are promising, with expander overall isentropic effectivenesses higher than 70% and cycle efficiencies comparable or higher than the typical efficiencies reported in the scientific literature for the considered temperature range. New steady-state semi-empirical models of each component are developed and validated with the experimental data. The global model of the ORC prototype allows predicting its performance with a good accuracy and can be exploited to simulate possible improvements or alternative cycle configurations. Dynamic models of the cycle are also developed for the purpose of evaluating the system's reaction to transient conditions. These models are used to define and compare different control strategies. The issues of cycle optimization and fluid selection are treated using the steady-state semi-empirical models. The thermodynamic optimization of such cycles is first demonstrated by practical examples. Furthermore, three different methods for fluid selection are proposed, investigated and compared. Their respective advantages and fields of application are described. Finally, two prospective studies of small-scale ORC systems are proposed. The first one is a solar ORC designed for the rural electrification of remote regions in Africa. This prototype aims at competing with the photovoltaic technology, with the advantage of generating hot water as by-product. The second prospective study deals with the recovery of highly transient heat sources. Advanced regulation strategies are proposed to address the practical issues inherent to such systems. These strategies are compared with the state-of-the-art strategies and show a non-negligible potential of performance improvement. [less ▲]

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See detailCompétitivité des filières rizicoles burundaises: le riz de l'Imbo et le riz des marais
Gahiro, Léonidas ULg

Doctoral thesis (2011)

Le riz est une culture récente, pratiquée surtout dans la plaine de l'Imbo et dans les marais de moyenne altitude du Burundi. D'une part, les ressources disponibles et les technologies de production ... [more ▼]

Le riz est une culture récente, pratiquée surtout dans la plaine de l'Imbo et dans les marais de moyenne altitude du Burundi. D'une part, les ressources disponibles et les technologies de production rendent le riz de l'Imbo plus compétitif que le riz des marais. D'autre part, la majorité des qualités locales s'avèrent moins compétitives que celles importées de l'Asie et la Tanzanie. [less ▲]

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See detailContribution au développement d'un dispositif expérimental d'atomes froids de fer et spectroscopie à ultra-haute résolution de cet atome
Krins, Stéphanie ULg

Doctoral thesis (2011)

Le présent travail est dédié à la conception, la modélisation et l'implémentation d'un dispositif expérimental visant, pour la toute première fois, à piéger et à refroidir par laser des atomes de fer ... [more ▼]

Le présent travail est dédié à la conception, la modélisation et l'implémentation d'un dispositif expérimental visant, pour la toute première fois, à piéger et à refroidir par laser des atomes de fer. Dans ce cadre, une contribution majeure au développement de ce dispositif est rapportée ici. Cette contribution comprend notamment la mise en place de dispositifs de stabilisation laser sub-MHz adaptés aux transitions spécifiques de l'atome de fer à 372 et 358 nm, ainsi que l'implémentation d'un ralentisseur Zeeman sur des faisceaux de ces atomes issus d'un four à haute température. Par ailleurs, des déterminations à ultra-haute résolution de grandeurs spectroscopiques fondamentales liées aux effets isotopiques et de structure hyperfine des transitions à 372 nm et 373.7 nm du fer sont rapportées pour la toute première fois. Une comparaison extrêmement précise de la position de la raie du fer à 358 nm par rapport à la raie de l'iode moléculaire R(90)3-10 à 13957.8542 cm-1 est également présentée. Cette comparaison met à disposition avec la précision requise la dernière donnée spectroscopique qui était inconnue dans la littérature scientifique pour une mise au point optimale du refroidissement laser d'atomes de fer. Elle ouvre la voie à l'implémentation finale du dispositif présenté dans ce travail. [less ▲]

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See detailResidual Stress in Veneering Ceramic
MAINJOT, Amélie ULg

Doctoral thesis (2011)

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See detailOn the dichotomic collective behaviors of large populations of pulse-coupled firing oscillators
Mauroy, Alexandre ULg

Doctoral thesis (2011)

The study of populations of pulse-coupled firing oscillators is a general and simple paradigm to investigate a wealth of natural phenomena, including the collective behaviors of neurons, the ... [more ▼]

The study of populations of pulse-coupled firing oscillators is a general and simple paradigm to investigate a wealth of natural phenomena, including the collective behaviors of neurons, the synchronization of cardiac pacemaker cells, or the dynamics of earthquakes. In this framework, the oscillators of the network interact through an instantaneous impulsive coupling: whenever an oscillator fires, it sends out a pulse which instantaneously increments the state of the other oscillators by a constant value. There is an extensive literature on the subject, which investigates various model extensions, but only in the case of leaky integrate-and-fire oscillators. In contrast, the present dissertation addresses the study of other integrate-and-fire dynamics: general monotone integrate-and-fire dynamics and quadratic integrate-and-fire dynamics. The main contribution of the thesis highlights that the populations of oscillators exhibit a dichotomic collective behavior: either the oscillators achieve perfect synchrony (slow firing frequency) or the oscillators converge toward a phase-locked clustering configuration (fast firing frequency). The dichotomic behavior is established both for finite and infinite populations of oscillators, drawing a strong parallel between discrete-time systems in finite-dimensional spaces and continuous-time systems in infinite-dimensional spaces. The first part of the dissertation is dedicated to the study of monotone integrate-and-fire dynamics. We show that the dichotomic behavior of the oscillators results from the monotonicity property of the dynamics: the monotonicity property induces a global contraction property of the network, that forces the dichotomic behavior. Interestingly, the analysis emphasizes that the contraction property is captured through a 1-norm, instead of a (more common) quadratic norm. In the second part of the dissertation, we investigate the collective behavior of quadratic integrate-and-fire oscillators. Although the dynamics is not monotone, an “average” monotonicity property ensures that the collective behavior is still dichotomic. However, a global analysis of the dichotomic behavior is elusive and leads to a standing conjecture. A local stability analysis circumvents this issue and proves the dichotomic behavior in particular situations (small networks, weak coupling, etc.). Surprisingly, the local stability analysis shows that specific integrate-and-fire oscillators exhibit a non-dichotomic behavior, thereby suggesting that the dichotomic behavior is not a general feature of every network of pulse-coupled oscillators. The present thesis investigates the remarkable dichotomic behavior that emerges from networks of pulse-coupled integrate-and-fire oscillators, putting emphasis on the stability properties of these particular networks and developing theoretical results for the analysis of the corresponding dynamical systems. [less ▲]

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See detailStudy of the ecology, population structure and dynamic of the macroalgae Codium elisabethae in Faial (Azores) with underwater visible imagery.
Sirjacobs, Damien ULg

Doctoral thesis (2011)

Codium elisabethae O.C. Schmidt is a dark green globose macroalgae isolating an internal sea water volume in a lumen. Codium elisabethae is endemic to the Macaronesian region and is very similar to Codium ... [more ▼]

Codium elisabethae O.C. Schmidt is a dark green globose macroalgae isolating an internal sea water volume in a lumen. Codium elisabethae is endemic to the Macaronesian region and is very similar to Codium bursa C. Agardh whose distribution range spans the West-European, North-Western African and Mediterranean coasts and which was proposed as a potential indicator of coastal environmental changes based on the study of its ecology, revealing its long lifespan. Until recently, relatively little was known on Codium elisabethae as compared to the more widespread Codium bursa. To fill this gap, the present research aimed at producing an accurate description of the ecology and population dynamics of Codium elisabethae occupying the rocky shores of the Monte da Guia Special Area of Conservation (SAC)/Natura 2000 network (Faial, Azores). To achieve this, two reference sites were selected for long term monitoring: a sheltered no-go reserve exhibiting a dense Codium elisabethae population (Caldeirinhas), and a location experiencing more exposed conditions holding a sparser population (Ponta Furada). First, environmental conditions experimented by benthic organisms were extensively quantified and interpretated in regard to topographical particularities of each site. The study of reproduction dynamics showed a persistent summer fertility and an important vegetative reproduction. Important nutrient concentration ratio was found between the Codium elisabethae lumen water and surrounding sea water (mean ratios: nitrates: 5.7; ammonium: 3.4; phosphates: 3.1). In situ counting’s and size measurements revealed much higher densities of young recruits in the site of the Caldeirinhas (order of 20 ind/m²) than in the one of Ponta Furada (order of 1/m), for both summer and winter. Secondly, underwater visible imagery was exploited as an efficient and non-invasive alternative to classical in situ population estimation. Between August 2003 and November 2005, fifteen seabed photo coverages were collected by scuba-divers. Subsequent image processing consisted in mosaicing, interactive identification, and automatic change detection methods. This allowed quantifying the seasonal fluctuations of population structures (density, percentage cover and biomass) and of population dynamics (growth, recruitment, mortality and primary production). Chi-square tests of image-derived estimates and in situ measurements confirmed the validity of a centimeter precision for the estimation of population structure of individuals above 4 cm diameter. Important variability of population structure and density was observed within the sites at small spatial scales. Significant differences of population structure and dynamics parameters are demonstrated between two close-by but contrasting coastal habitats. Population density showed a sharp reduction in autumn 2003 and did not recover fully in spring and summer 2004. During the following year, population of the protected site maintained density and biomass, while at the exposed site population density dropped. In contrast with conclusions from earlier studies on the Azorian Codium elisabethae and on the Mediterranean Codium bursa, the present study revealed higher biomass (34 - 730 g dry wt.m-²), growth rates (up to 2.5 cm/month in summer) and primary production (0.53 – 11.5 g dry wt.m-².day-1), and demonstrated the seasonal fluctuations of these parameters for the studied Azorian Codium elisabethae population. The lifespan of Codium elisabethae was estimated to reach at least 7 years in the SAC of Monte da Guia based on an integration of average seasonal growth rates measured by imagery on extended population samples. This study demonstrates the high potential of registered underwater photomosaics time-series for long term surveys of macroalgae populations. This work provides also a strong framework to further developments and applicability to other species, which should be helpful to strengthen our current understanding of benthic ecosystem processes. [less ▲]

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See detailIo's interaction with Jupiter's magnetosphere
Dols, Vincent ULg

Doctoral thesis (2011)

Io, the innermost Galilean moon of Jupiter, is the most volcanic body of the solar system. This volcanism is responsible for a tenuous atmosphere composed mainly of S, O and SO2. This atmosphere is ... [more ▼]

Io, the innermost Galilean moon of Jupiter, is the most volcanic body of the solar system. This volcanism is responsible for a tenuous atmosphere composed mainly of S, O and SO2. This atmosphere is constantly bombarded by the plasma that co-rotates with the magnetic field of Jupiter, producing new ions and perturbing locally the magnetic field. This local perturbation is responsible for auroral emissions in the atmosphere of Jupiter, at the foot of Io’s flux tube. The spacecraft Galileo made five flybys of Io between 1995 and 2001 at very low altitude (~100’s km) and made plasma and magnetic field measurements that reveal the complexity of Io’s interaction with Jupiter. Past studies have tackled the modeling of this interaction using different complementary approaches, each shedding a new light on the issue but each involving some simplifications. The MHD models (Linker et al., 1998) are based on an a priori parameterization of the ionization in the atmosphere, generally assuming spherical symmetry and a single atmospheric and plasma species (representative of O and S). They ignore the important effect of the cooling of electrons as well as the multi-species composition of both the plasma and the atmosphere. The two-fluid approach (Saur et al., 1999) computes precisely the ionization and collisions in the atmosphere of Io but make the assumption of a constant magnetic field, limiting the self-consistency of the model and potentially introducing large quantitative errors. We combine a multi-species chemistry model of the interaction that includes atomic and molecular species with a self-consistent Hall-MHD calculation of the flow and magnetic perturbation to model as self-consistently as possible the plasma variables along the different flybys of Io by the Galileo probe. [less ▲]

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See detailMODELISATION DE L’ACTIVITE DES BACTERIES DU SOUFRE EN LAGUNAGE
Harerimana, Casimir ULg

Doctoral thesis (2011)

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See detailSignal transduction in photodynamic therapy-mediated cell death
Coupienne, Isabelle ULg

Doctoral thesis (2011)

Les glioblastomes sont des tumeurs du cerveau comptant parmi les plus fréquentes et les plus agressives. En effet, l’espérance de vie médiane des patients est d’environ quinze mois après diagnostic ... [more ▼]

Les glioblastomes sont des tumeurs du cerveau comptant parmi les plus fréquentes et les plus agressives. En effet, l’espérance de vie médiane des patients est d’environ quinze mois après diagnostic. Malgré d’intenses recherches et l’utilisation de traitements combinant la chirurgie, la radiothérapie et la chimiothérapie, le pronostic des patients n’a guère évolué depuis une vingtaine d’années. Ces tumeurs sont caractérisées par la présence de diverses altérations génétiques et, généralement, par une activation constitutive du facteur de transcription NF-κB. Étant un régulateur majeur de l’apoptose et de la survie cellulaire, ce facteur pourrait jour un rôle central dans la résistance des glioblastomes aux diverses thérapies. Au cours de ce travail, nous avons étudié les effets de l’inhibition du NF-κB sur la mort cellulaire des glioblastomes induite en réponse à un traitement par PDT, dont l’efficacité repose sur la production d’espèces réactives de l’oxygène suite à la présence simultanée d’un photosensibilisateur, de lumière et d’oxygène. Ainsi, nos résultats montrent que les cellules dans lesquelles le NF-κB est inhibé présentent une sensibilité accrue au traitement par rapport aux cellules non-inhibées. De plus, cette augmentation de mort cellulaire est majoritairement due à de la nécrose. Le traitement par PDT conduit également à l’apparition d’autophagie cytoprotectrice dont l’inhibition améliore l’efficacité du traitement. Nous nous sommes ensuite focalisés sur la mort par nécrose et avons démontré l’implication de la kinase RIP3 dans la mort nécrotique induite par PDT. Il est apparu que l’oxygène singulet produit au cours du traitement était à l’origine de la nécrose RIP3-dépendante. Cependant, les intermédiaires transductionnels et la manière dont le NF-κB exerce ses effets anti-nécrotiques demeurent encore inconnus. Enfin, afin de mieux comprendre le rôle joué par RIP3 dans la mort induite par PDT, nous avons utilisé la lignée d’ostéosarcome U2OS, déficiente en cette protéine, et au sein de laquelle nous en avons restauré l’expression. De manière surprenante, les cellules sauvages se sont révélées plus sensibles au traitement que les U2OS exprimant RIP3. De plus, la lignée RIP3-U2OS montre un taux d’apoptose supérieur à celui de son homologue sauvage. Cette divergence peut en partie s’expliquer par une induction d’autophagie plus importante au sein des RIP3-U2OS. Celle-ci, pouvant être un mécanisme pro-survie, peut leur conférer une protection contre la mort cellulaire en facilitant l’élimination des organelles endommagés. Enfin, nous avons déterminé que les cellules sauvages présentent un taux de nécrose plus important que les cellules RIP3-U2OS en réponse au traitement. Nos résultats ont dont permis de prouver (i) que l’inhibition du NF-κB améliorait la sensibilité des glioblastomes à la mort cellulaire induite par un traitement par 5-ALA-PDT, (ii) que celle-ci était, dans ce cas, majoritairement de la nécrose RIP3-dépendante et (iii) de mettre au jour un rôle pour RIP3 dans la régulation de l’apoptose et de l’autophagie induites par PDT. [less ▲]

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See detailLa résilience des banques libanaises : analyse de certains aspects de la gestion des risques dans le cadre de l'accord de Bâle
El Khoury, Ghada ULg

Doctoral thesis (2011)

Located in an environment of high uncertainty, supervisors in Lebanon have decided to comply with regulations issued by the Basel Accords and to monitor the new Basel Committee prudential framework. This ... [more ▼]

Located in an environment of high uncertainty, supervisors in Lebanon have decided to comply with regulations issued by the Basel Accords and to monitor the new Basel Committee prudential framework. This thesis focuses on the Lebanese banking sector and on Basel II specific aspects in the Lebanese context. Four research areas are covered : 1. Evaluation of the capitalization level of Lebanese banks as required by Basel II prudential standards. 2. Lebanese sovereign risk analysis and its impact on the sustainability of banks through the measurement of probability of default of the Lebanese state on its Eurobonds denominated in U.S. dollars. 3. Examining the question of bank balance sheet procyclicality generated by the accounting and prudential framework, and by contextual factors specific to the resilience of the Lebanese banking sector. 4. Evaluation of the adaptation level of the Lebanese banking sector to new risk management approaches by estimating the probability that banks will well manage their risks. From a comparative analysis of the regulatory and economic capital, we found that 14 banks have a high economic capital relative to regulatory capital under Basel II in 2005. We also observed that the risks faced by Lebanese banks are primarily related to credit risk and sovereign risk in particular. Applying the valuation model of default risk, developed by Merrick (2001), and based on a review of scientific literature, we proposed a synthetic measure of credit risk of the Lebanese US dollar denominated Eurobonds. The results show that changes in the probability of default and recovery rates are explained by the trust vis-à-vis the market and state. Based on a review of the scientific literature, we have developed theories of economic fluctuations and financial instability. The analyses of procyclicality in the Lebanese context have shown that the factors leading to a balance sheet procyclicality in the Lebanese banking sector are atypical. We have also shown the resilience of the Lebanese banking sector to recent shocks and crises. Through a survey conducted between November 2009 and February 2010, we assessed the level of adaptation of the Lebanese banking sector to new risk management approaches. The results show that some banks have become more aware of the importance of developing proper risk management practices. Therefore, other banks remain in a precarious stage. [less ▲]

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See detailExtension of the Liège Intranuclear Cascade Model to the 2-15 GeV Incident Energy Range
Pedoux, Sophie ULg

Doctoral thesis (2011)

The Liège Intra-Nuclear Cascade model (INCL4) has been shown to be quite successful for the description of spallation reactions. However its validity domain is limited to an upper incident energy of ~2 ... [more ▼]

The Liège Intra-Nuclear Cascade model (INCL4) has been shown to be quite successful for the description of spallation reactions. However its validity domain is limited to an upper incident energy of ~2 GeV, because inelastic elementary processes are restricted to the excitation and de-excitation of the Delta resonance. In this thesis, the INCL4 model is extended to higher incident energy. This is realised by including other inelastic elementary collisions, direct multipion production in elementary nucleon-nucleon and pion-nucleon collisions. This is somehow opposite to the usual extension to high energy of such models, as it is usually realised by including excitation of heavier baryonic resonances. Experimental data and isospin symmetry have been exploited in the implementation of multipion channels, but we could not avoid to introduce specific models for the energy-momentum and charge repartition on the final pions. The predictions of the modified model for production of protons, neutrons and charged pions by proton and pion beams off nuclei are compared with experimental data. A short study on nuclear fragmentation is also presented. [less ▲]

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See detailBouncing droplets, the role of deformations
Terwagne, Denis ULg

Doctoral thesis (2011)

Nowadays, innovative applications such as "lab-on-a-chip", micro-reactors or biological chips are developed for industry, biology or medicine. Capillary issues are encountered which are not yet fully ... [more ▼]

Nowadays, innovative applications such as "lab-on-a-chip", micro-reactors or biological chips are developed for industry, biology or medicine. Capillary issues are encountered which are not yet fully understood. It is therefore essential to open up ways to manipulate tiny amounts of liquid in order to mix them, encapsulate them or to create emulsions. The bouncing droplets on an oscillating liquid interface allow their manipulation. Indeed, under certain conditions, droplets can bounce indefinitely on a bath surface as long as the squeezed air film which separates the drop from the bath is renewed at each bounce. We chose to study deformable droplets on a non-deformable bath. The droplets are deformable because they are large or made of a low viscous oil, the liquid of the bath being highly viscous silicone oil. We investigated how the deforma- tions, the stability and the trajectories of the droplets depends on the forcing parameters such as the frequency and the amplitude of the oscillation. We also studied the possibility of mixing and emulsifying droplets on the bath. Finally, we showed the effect of the deformation of the bath on these bouncing droplets and studied the trajectories of walking droplets [1] which are used as a model for quantum-like particles [2-5]. In this manuscript, we reported an exploration of the droplets behavior as a function of the ability of the bath and/or the droplet to deform. Depending on the forcing frequency, specific deformation modes are excited on the bouncing droplets. We used these modes to rationalize their bouncing stability and to create double emulsions in a compound droplet. Then, we determined numerically the complex bifurcation diagrams of the trajectories of a bouncing droplet thanks to a model based on a spring. On a low viscous bath, we evidenced the importance of its deformation. We showed that a walker exists as soon as the droplet experiences, once every two oscillation periods, a jump high enough to trigger a Faraday wave. As a consequence, we have to take the bouncing droplets into account when looking for an alternative way to manipulate them or as a model of quantum-like particles. The bouncing droplets still exhibit lots of intriguing behaviors which have yet to be explained. They can therefore remain the focus of future works. [less ▲]

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See detailApplication de la spectroscopie Raman à l’analyse de colorants sur fibres de coton dans le contexte de la criminalistique
Lepot, Laurent ULg

Doctoral thesis (2011)

Forensic examination of textile fibres is based on fibre morphology and on fibre material and dyes characterization. Cotton is the most frequently used fibre in textiles but also the most encountered in ... [more ▼]

Forensic examination of textile fibres is based on fibre morphology and on fibre material and dyes characterization. Cotton is the most frequently used fibre in textiles but also the most encountered in casework. While man-made fibres show various morphologies and materials, cotton is a natural cellulosic fibre with constant morphology. Cotton fibres examination can consequently be summarized in the characterization of fibre dyes. However forensic needs require non-destructive, fast and sensitive techniques. For fibres microspectrophotometry (MSP) is the commonly used technique and the obtained UV-Vis absorption spectrum reflects dyes used to colour the fibre. Any other technique suitable for dye characterization is thus helpful to reinforce MSP results on cotton fibres. Raman spectroscopy is a fast non-destructive technique, easy to integrate into the fibre analytical sequence without any additional sample preparation. Moreover it provides specific molecular information and seems convenient for the study of coloured molecules. This work allowed to demonstrate the potential of the technique in dyed cotton fibres examination through the characterization of pure dyes but also the ability to detect different components in dye mixtures. In order to help dye identification spectral databases were built using Raman spectra collected in the present work. Unfortunately such a database will never be exhaustive and the identification of an unknown dye would be compromised. An interesting option is to identify the general chemical class of the unknown dye, especially to evaluate its rarity. The recognition of some dye chemical classes has been made by the mean of characteristic peaks but this method remains somewhat subjective. This subjectivity can be bypassed using chemometric techniques; they are able to predict chemical class membership on the basis of Raman specific information. Some experiments have been performed on Raman spectra using PCA models and the SIMCA classification tool. [less ▲]

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See detailStudy of the Cape Ghir upwelling filament using variational data analysis and regional numerical model
Troupin, Charles ULg

Doctoral thesis (2011)

Aim: Upwelling filaments are shallow, elongated structures of cool waters often visible in the regions of coastal upwelling. The present thesis aims to improve our knowledge on the mechanisms responsible ... [more ▼]

Aim: Upwelling filaments are shallow, elongated structures of cool waters often visible in the regions of coastal upwelling. The present thesis aims to improve our knowledge on the mechanisms responsible for the generation of filaments. Location: the study is centered on the Canary Current Upwelling system, located off northwest Africa, in particular around Cape Ghir (30°38'N, 9°53'W), where these filaments are frequently observed. Methods: - We compiled historical in situ data to build a high-resolution climatology of temperature and salinity in the region of interest using the Data Interpolating Variational Analysis (\diva) method. - We ran the experiments with the numerical model ROMS to investigate the processes responsible for the filament generation. - We collected in situ measurements during a cruise in August-September 2009, in the frame of the CAIBEX project, in the filament area and analyzed them to get a detailed description of the Cape Ghir filament, its variability and its biogeochemical characteristics. - We computed anomalies of several variables with respect to a long-term mean to examine the time-evolution of the Canary Current Upwelling system. Results: The climatology showed improvements with respect to existing products, especially in the coastal area, and was a valuable asset to provide initial and boundary conditions for the numerical model. The results of the simulations underlined the role of the wind in the filament generation and confirmed our assumption of a mechanism based on the potential vorticity balance. Preliminary analysis of the cruise data allowed us to characterize the filament physical and biological properties, in particular we observed the signal of a subsurface (at a depth of 300~m) anticyclonic eddy on the northern flank of the filament, also present in the numerical model outputs. Anomalies for the year 2010 revealed a widespread warming over the tropical and subtropical Atlantic Ocean and a diminution of the upwelling activity. We attributed these anomalies to a weakening of the winds, itself related to a strongly negative North Atlantic Oscillation (NAO) index. [less ▲]

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See detailImpacts des changements climatiques passés et présents sur la génétique et la démographie du Cincle plongeur (Cinclus cinclus)
Hourlay, Frederic ULg

Doctoral thesis (2011)

Climate change is emerging as the greatest threat to natural communities in many, if not most, of the world’s ecosystems in coming decades. Numerous studies have revealed present and probable future ... [more ▼]

Climate change is emerging as the greatest threat to natural communities in many, if not most, of the world’s ecosystems in coming decades. Numerous studies have revealed present and probable future consequences that climate change will have on many animal and vegetal species. According to these studies, birds could be affected, mostly negatively, in various ways : distribution, abundance, phenology, ethology ... The purpose of this work is to determine how the White-throated Dipper (Cinclus cinclus), a Palearctic, temperate, passerine bird that is exclusively associated with flowing water, reacted to the climate changes that occurred during the Pleistocene, and how climate change currently affects this species : - For this purpose, we conducted a phylogeographic study : we analysed three fragments of mtDNA (i.e. fragments coding for cytochrome b, ND2 and domains II and III of the controle region) from 106 tissue samples originating from 24 dipper populations, mostly located in the Western Palearctic. - The second part of this work consisted in analysing ringing recoveries and nest-boxes frequentation from a dippers population settled on the river Syre and its tributaries (Luxemburg) and followed from 1979 to 2001. Populations census were also conducted on different water courses in Luxemburg, in order to determine dipper habitat preferences. 1. Phylogeography of the dipper in the Western Palearctic region In spite of a low genetic variability, the results of our phylogeographic study reveal a complex phylogeographic structure for this species with at least five distinct lineages for the Western Palearctic region. As for many species of the Western Palearctic fauna and flora, this genetic structure is probably linked to the isolation of populations in different southern refuges during glacial periods. Furthermore, the isolation of populations in Scandinavia and/or Eastern regions, but also in Morocco and probably in Corsica, was accentuated by ecological and biogeographic barriers during Quaternary interglacial periods. During glacial periods, Italy, Sicily and the Balkano-Carpathian region acted as major refuge zones for the dipper. At the end of the last ice age, Western Europe was repopulated by dippers from a refuge located in Italy and, probably, South-East France, while Eastern Europe was recolonised by Balkano-Carpathian birds. A large contact zone between these two lineages was evidenced and extends from Luxembourg to Hungary. Finally, our results indicate the need to clarify the taxonomic status of the dipper, especially concerning the European subspecies whose validity appears uncertain. 2. Dipper demography – Influence of climate change and other anthropic pertubations Results obtained from the analysis of demographic and morphologic variables of the Luxemburger population are in agreement with results obtained from other European populations. Differences observed between these populations are mostly due to climate and habitat quality differences. However, other factors could also partly explain these differences. As for other places in Europe, nest boxes installation dramatically increased dippers population size on the river Syre. Our results also suggest that the installation of nest boxes could influence some demographic and morphologic variables, probably as a result of population increase. But, above all, our results show how temperatures and precipitations affect these variables, and particularly laying dates. Climatic changes that occurred during the last decades provoked earlier laying dates. Whereas clutch size and nest size remained unchanged, the Luxemburger population size decreased during the same period, as observed for other European populations. The main cause to this decrease should be an increase of environmental instability inducing notably a decrease of food ressources for dippers. As a result, we observed a significant decrease of females body weight during this period. Climate change will also probably have a serious impact on dipper genetic diversity, leading to the disappearance of the most southern populations and eventually of certain genetic clades. The results obtained concerning the taxonomic status of the dipper and its demography could be useful in the framework of a conservation program, if necessary. In this perspective, the development of habitat suitability prediction tools, as the one we developed, could also be very helpful. [less ▲]

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See detailUnveiling the internal structure and evolution of massive stars through their pulsation modes
Godart, Mélanie ULg

Doctoral thesis (2011)

Stars in the night sky are not as quiet as they seem. A human being wandering on Earth few billions years ago would have seen a different night sky, with different stars forming different constellations ... [more ▼]

Stars in the night sky are not as quiet as they seem. A human being wandering on Earth few billions years ago would have seen a different night sky, with different stars forming different constellations. Moving forward in time, he would have been the witness of stellar evolution as some stars would have suddenly shined while others disappeared forever. Hard to realize at a time scale of human life, stars are born, evolve, and die in a limited lifetime which can last only a few million years for the most massive to trillion years for the less massive. Fortunately, it is not necessary to wait that long to study the formation and evolution of stars. Stellar evolution can be studied on shorter time scales, on thousands of stars, at various evolutionary stages. This is of great importance as stars shape the Universe and produce the chemical elements at the origin of life. Probing the internal structure of stars is however very challenging due to the opacity barrier of their superficial layers. One way to get around this issue is to study and interpret stellar pulsations. As seismologists extract information about Earth interior trough the study of earthquakes, asteroseismologists can study the internal structure of stars by studying their oscillations. In this thesis, this technique is used to study the internal structure and evolution of massive stars which are at least eight times more massive than our Sun and which have a spectral type between O and B. The first part of this work is devoted to the determination of the $\kappa$-mechanism instability domains for massive stars. In order to extend the computations to the post-main sequence phase of evolution, we develop a numerical technique in which the non-adiabatic computations for the stellar core are made, independently than for the envelope, within the quasi-adiabatic and the asymptotic treatment. In a second step, we investigate the pulsations modes in O main sequence stars and in B post-main sequence stars. The presence of g-modes in post-main sequence stars is closely related to the internal structure of the star and we study the effects of several physical factors on the occurrence of these modes. Finally, the last part of this work is dedicated to the characterization of strange mode pulsations. In particular, we focus on strange modes having an adiabatic counterpart, which are trapped into a superficial cavity. The effect of the model atmosphere on the excitation is investigated in addition to the characterization of their eigenfunctions. [less ▲]

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See detailNarrateur, personnage et leceur virtuel: vers une méthode d'analyse intra-relationnelle
Goin, Emilie ULg

Master's dissertation (2011)

Dans l'étude d'un possible dialogisme entre les instances internes au récit que sont le narrateur, le personnage et le lecteur virtuel (soit l'instance de lecture présupposée par le texte), ce travail ... [more ▼]

Dans l'étude d'un possible dialogisme entre les instances internes au récit que sont le narrateur, le personnage et le lecteur virtuel (soit l'instance de lecture présupposée par le texte), ce travail pose notamment les questions des subjectivèmes, de leur assemblage en point de vue et des articulations de points de vue hétérogènes: comment peut-on les repérer, identifier différentes formes d'assemblage/articulation et déterminer leur force illocutoire? [less ▲]

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See detailDes indications sur un détour. Les rapports entre Althusser et Spinoza
Mancuso, Eva ULg

Master's dissertation (2011)

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See detailCaractérisation des effets de température dans la zone endommagée autour de tunnels de stockage de déchets nucléaires dans des roches argileuses
Dizier, Arnaud ULg

Doctoral thesis (2011)

La solution du stockage des déchets nucléaires de haute activité et de longue durée de vie dans les couches argileuses profondes comporte de nombreuses incertitudes. Pour combler celles-ci de nombreux ... [more ▼]

La solution du stockage des déchets nucléaires de haute activité et de longue durée de vie dans les couches argileuses profondes comporte de nombreuses incertitudes. Pour combler celles-ci de nombreux projets européens sont réalisés de façon à les minimiser. Le projet TIMODAZ (Thermal Impact On the Damaged Zone Around a Radioactive Waste Disposal in Clay Host Rocks) étudie l'influence de la température sur la zone endommagée. Cette zone correspond à une zone soumise à la redistribution des contraintes lors de l'excavation constituant un lieu de développement de micro et macro fractures. Cet endommagement mécanique est complété par un endommagement thermique lors de la pose des canisters qui vont émettre de la chaleur durant des milliers d'années et donc provoquer une augmentation de la température du massif argileux. Cette élévation de température de l'argile peut faire apparaitre des déformations plastiques thermiques de contraction. Cette nouvelle plasticité peut contribuer au développement de la zone endommagée. L'objectif de ce travail est donc de caractériser la zone endommagée autour des tunnels souterrains, construits dans l'Argile de Boom, soumis à des élévations de température induites par les déchets nucléaires. Durant ce travail, une loi de comportement thermo-mécanique est implémentée. Celle-ci se base sur un "modèle à chapeau" étendu à la thermo-plasticité. Ce modèle comprend la combinaison d'un modèle à frottement interne, d'un critère Cam-Clay et d'un critère de rupture à la traction. Ce modèle est étendu à la température et en particulier à la thermo-plasticité en considérant les travaux de Sultan. Les paramètres thermo-hydro-mécaniques de l'Argile de Boom sont identifiés et servent à la modélisation d'expériences de laboratoire et in situ. Ces expériences consistent en outres en un cylindre creux, en l'expérience de chauffage ATLASIII et en l'expérience à grande échelle PRACLAY. Ces trois expériences ont pour objectif d'étudier l'Argile de Boom d'une petite échelle à une plus grande représentative du massif argileux. L'étude du comportement dans la zone élastique et plastique est également prise en compte via ces différentes expériences. Les résultats, avec différentes lois de comportement, montrent que l'influence de la thermo-plasticité est faible mais non négligeable vis-à-vis des déformations déviatoriques engendrées par l'excavation. [less ▲]

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See detailInSAR Applied to the Study of Active Volcanic and Seismic Areas in Africa
Wauthier, Christelle ULg

Doctoral thesis (2011)

Two active volcanic areas situated in immature portions of the East African Rift System (EARS): the Lake Kivu (Dem. Rep. of Congo) and Lake Natron (Tanzania) regions, which are located in the western and ... [more ▼]

Two active volcanic areas situated in immature portions of the East African Rift System (EARS): the Lake Kivu (Dem. Rep. of Congo) and Lake Natron (Tanzania) regions, which are located in the western and eastern branch, respectively, are still poorly known. Both areas indeed lack of ground-based networks, due to security problems or difficult field accessibility. The Lake Kivu area includes two volcanoes erupting frequently: the Nyamulagira and Nyiragongo volcanoes. The SAR database covering these volcanoes in- cludes data from JERS, ERS-1&2, ENVISAT, ALOS, RADARSAT-1&2 satellites back from year 1996. SAR Interferometry (InSAR) is thus applied to study the ground de- formations. MT-InSAR approaches, such as the ”‘StaMPS”’ method, are used to give us new complementary information to better constrain the previous established eruption models, or gain new insights on eruptions missed by the conventional InSAR, as well as on magmatic and tectonic activity. When enough constrains are available, the ground displacements are modeled using a 3D-Mixed Boundary Elements Method combined with a neighborhood algorithm. Hence, the 1996, 2002, 2004 and 2010 eruptions of Nyamu- lagira are modeled. The modeling results, coupled with the StaMPS MT-InSAR results, bring new insights concerning the magma plumbing system of this poorly known volcano and its eruptive mechanisms. The collapse of the eastern flank of Nyamulagira, along the NNW-trend fractures network linking Nyamulagira and Nyiragongo volcanoes, can also be identified. InSAR also captures the ground displacements associated with the January 2002 Nyiragongo eruption. The modeling of this major event evidences a deep magma intrusion beneath the Lake Kivu. Such intrusions should be taken into account for hazard assessment. The magma could indeed finds its way to the Lake Kivu floor, as evidenced by the presence of several old phreato-magmatic cones, and causes a lake overturn. The low dikes overpressures found in the North Kivu and Lake Natron areas indicate that, although the rift is considered as immature, the rift extension is driven by the supply of magma from depth, rather than by the tectonics. A new criterion to identify the rifting stage is found to be the stress state. In the southern part of the rift, tectonic activity dominates, indicating that the tectonics is probably driving the rift opening there. [less ▲]

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See detailDynamique des transactions foncières et vulnérabilité rurale au Niger : cas des communes rurales de Tchadoua et Yaouri
Lawali Mani, Sitou ULg

Doctoral thesis (2011)

Summary In Niger, agriculture is the principal activity of the rural populations. Unfortunately the access to the land becomes very difficult to the farmers in the center-south of the country. This area ... [more ▼]

Summary In Niger, agriculture is the principal activity of the rural populations. Unfortunately the access to the land becomes very difficult to the farmers in the center-south of the country. This area is confronted to the space saturation and the emergence of the land transactions whose causes, process and impacts on the agricultural households are little known. The study undertaken in the rural municipality of Tchadoua and Yaouri aimed at analyzing the dynamics of the land transactions in bond with the rural vulnerability in terms of the stakes of access and management of the grounds, but also their securisation. The problems were studied with a multidisciplinary approach. The analyses (quantitative and qualitative) were carried out on the basis of the data collected in the village areas of Maijanguero and Gomba through cards of investigations and semi-structured interviews with a sample of 30% of the households. We also used participatory observations of agricultural practices and consultation of different sources of documentation. Administration and others authorities have been also interviewed aswel as members of the land commissions and the intermediaries of the transactions. The results obtained show that the problem of access and management of the land in these agricultural areas is an important concern for rural producers. The land blocking due to the strong demographic pressure and the increase of economic stakes (crop rent) influence the excessive parceling out of the grounds and the individualization of the farms. This individualization supports consequently, the emergence of the commercial land speculations for the profit of the economic operators installed from now in logic of monopolization of grounds. The purchase, the pledge and the lease constitute the principal access modes to the ground instead of old forms of solidarity (gift, loan). Also, the new agrarian initiatives of assistance appear and take part in the improvement of the socio-economic conditions of the rural households. The results also made it possible to highlight a diversity of trajectories of the exploitations. The land ‘’monetarisation’’ influenced strongly the land management and reinforced the exclusion of the vulnerable groups. The strong changes of technical transformation and farming system are observed. It as revealed as the land accumulation or ‘’décapitalisation’’ depends of the type of farm, its strategy and its revenue. Indeed, three tendencies become apparent from the trajectories: great manufacturing units with dominant commercial accumulate land, use the hired labor work and araw cash crop (souchet); a strong land ‘’decapitalisation’’ at the extremely vulnerable and without viable strategy of adaptation in the long term. Lastly, the small farm witch made a diversification and a strong intensification, and there resist to the multiple attempts of land spoliation. These last constitute a model of stable and durable farm whose strategy is based primarily on the agricultural intensification through effective and less expensive agroforestry practices to increase their production and their land capital. The informel and discrete character of land transactions and the networks of intermediation by which are negotiated the land sales accentuate the land insecurity and contribute to increase the land prices. The analysis of the securisation practices of the land rights proves that legal formalization though timid, reduced considerably the frequency of the rural conflicts and offers agricultural opportunities of investments. However, the land commissions encounter difficulties which, slow down the generalization of the legal formalization of transactions. All things considered, the land problem remains a central stake of development thus, the securisation of the land rights of the rural poor must be a priority of the priorities to reach a durable food safety. It is thus urgent to make the land commissions more operational in their giving the means of operation in order to ensure a broad diffusion of the procedures of formalization for more impact and also encouraging the producers through small subsidies to practice the carrying agri-environmental measurements. [less ▲]

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See detailLe Caire : carrefour des ambassades. Étude historique et diplomatique de la correspondance échangée entre les sultans mamlouks circassiens et les souverains timourides et turcomans (Qara Qoyunlu-Qaramanides) au XVes. d’après le BnF ms.ar. 4440.
Dekkiche, Malika ULg

Doctoral thesis (2011)

Pendant près de 250 ans, les sultans Mamlouks d’Égypte (1250) et de Syrie (1260) furent les représentants suprêmes de l’Islam aussi bien aux yeux des Musulmans que des Chrétiens d’Occident. Leur capitale ... [more ▼]

Pendant près de 250 ans, les sultans Mamlouks d’Égypte (1250) et de Syrie (1260) furent les représentants suprêmes de l’Islam aussi bien aux yeux des Musulmans que des Chrétiens d’Occident. Leur capitale, Le Caire, s’érigea en véritable carrefour des ambassades venues des quatre coins du monde connu alors. Cependant, presque rien des archives de cette dynastie ne nous est parvenu sous sa forme originale. Heureusement, les secrétaires de chancellerie de cette époque nous ont laissé un nombre non négligeable d’ouvrages, manuels de chancellerie et Formulaires, dans lesquelles ils nous révèlent les pratiques de chancellerie en cours alors et nous présentent de nombreuses copies de lettres qui furent échangées entre les sultans mamlouks et d’autres dynasties, musulmanes, chrétiennes ou autres. La présente thèse de doctorat se fonde sur l’un de ces formulaires, conservé sous sa forme manuscrite à la Bibliothèque Nationale de France, Paris, sous la cote ms. ar. 4440. Nous avons extrait de ce manuscrit un corpus de 19 lettres échangées entre les sultans mamlouks et trois autres dynasties musulmanes du XVes. régnant sur un territoire allant de l’Anatolie à l’Iran en passant par l’Iraq: les Timourides, les Qara Qoyunlu et les Qaramanides. Après l’édition critique de ce corpus, nous nous sommes concentrée sur l’étude historique et diplomatique de celui-ci. La première partie de la thèse concerne l’étude historique du corpus et de ce que nous avons appelé « la réalité de l’ambassade ». Le protocole de réception des ambassades au Caire par les sultans mamlouks, est assez bien renseigné à travers les chroniques des historiens de l’époque. Il est important de bien connaître ces règles afin de mesurer l’importance que le souverain accordait à son correspondant. Après énonciation de ces règles protocolaires, nous proposons, pour chaque dynastie en question, un aperçu de l’état des relations qui étaient établies entre elles et les sultans mamlouks, avant de nous atteler à l’étude historique du corpus proprement dite. Pour ce faire, nous avons dépouillé années après années les chroniques mamloukes et tenté de remettre chacune des lettres du corpus dans le contexte de l’ambassade qui lui était propre. Enfin, nous nous sommes concentrée sur le contenu des messages de ces lettres et avons analysé les raisons qui étaient à l’origine de l’envoi de l’ambassade. Nous nous sommes rendue compte de l’importance que ces lettres possèdent en tant que sources historiques de la période couverte, car elles nous révèlent un grand nombre de détails omis par les historiens contemporains des faits, ce qui nous permet de réévaluer avec plus de précision le rôle que la dynastie mamlouke jouait encore à cette époque notamment en tant que représentant suprême de la communauté musulmane et ce malgré les affronts subis par les différents pouvoirs montants, comme les Timourides. Nous avons grâce à l’analyse du protocole de cérémonie et du contenu des messages deux grilles de lecture nous permettant d’évaluer l’état des relations établies entre les Mamlouks et les trois autres dynasties, mais pour que l’étude soit complète, il est une troisième grille qui doit être prise en compte. Elle nous est fournie par la diplomatique et elle fait l’objet de la seconde partie de notre thèse. Dans cette partie, nous nous sommes concentrée, outre sur notre corpus, sur l’étude des manuels de chancellerie de l’époque mamlouke et nous avons tenté, grâce à eux, de reconstituer les règles de chancellerie propres à la rédaction de la correspondance entre les sultans mamlouks et les souverains musulmans afin de mesurer de façon certaine les liens qui sous-tendaient les relations établies entre les différents correspondants. Une telle étude vient à point lorsque l’on sait le retard que la discipline diplomatique a pris dans le cadre des études arabo-musulmanes. Enfin, la mise en parallèle de cette partie avec la première nous permet de dresser un tableau assez complet de la perception que les Mamlouks avaient des autres dynasties avec lesquelles ils étaient en contact. [less ▲]

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See detail« L'affaire du voile", une construction médiatique. Les controverses autour du hijab dans Le Soir.
Luceno Moreno, Marta ULg

Master's dissertation (2011)

Depuis l’éclosion de « L’affaire du voile » en 1989 en Belgique, la question du voile a donné lieu à des fréquents controverses dans la presse. Après cinq ans de faible médiatisation, en avril 2009 ... [more ▼]

Depuis l’éclosion de « L’affaire du voile » en 1989 en Belgique, la question du voile a donné lieu à des fréquents controverses dans la presse. Après cinq ans de faible médiatisation, en avril 2009, l’affaire revient sur le devant de la scène médiatique. À partir de cette date, le voile va encore faire couler beaucoup d’encre dans les journaux belges, mais aussi elle va soulever des questionnements dans le monde politique. Cette augmentation d’attention tant médiatique que politique sur le voile a retenu l’attention de cette étude, qui s’est centré sur deux axes principaux : le traitement médiatique de la question et l’influence de cette médiatisation dans la mise à l’ordre du jour politique du voile. [less ▲]

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See detailElaboration d’un modèle d’écobilan de l’exploitation agricole irriguée. Cas du périmètre du Tadla – Maroc
Krim, Lhassan ULg

Doctoral thesis (2011)

In Morocco, the agro environmental problem is mainly translated by a degradation of the waters quality and a soils salinization under irrigation. In the, studied zone of the present work, the lands ... [more ▼]

In Morocco, the agro environmental problem is mainly translated by a degradation of the waters quality and a soils salinization under irrigation. In the, studied zone of the present work, the lands irrigation started since several decades by using waters of sometimes very degraded mineral quality, on one hand, and the agricultural intensification essentially marked by the application of excessive nitrogenous fertilizers doses, on the other hand, engendered a strong nitric pollution of groundwater table and a spectacular salinization of soils and waters. In order to contribute to the environmental assessment of the irrigated agriculture in Morocco, an Ecobalance model baptized "EcoTadla" (TEB) was elaborated and validated in the Tadla perimeter through the adaptation of the "EcoFerme" model (MEF) developed by the Fluid Mechanics and Environment Unity of the Gembloux Agro-Bio Tech – University of Liege (Belgium). The general objective is to establish an Ecobalance model allowing to quantify and to analyse the materials fluxes exchanged between the farm and its environment and consequently to improve and\or to correct the agricultural practices aiming at a better agro environment preservation within an eco-advice initiative framework. The analysis of the inadequacies of MEF to make an operational model in the studied context allowed to bring the adaptations to be brought as regards the definition of the basic hypotheses to hold in the new model construction, the quantification of the parameters to be used as inputs of the model and the modifications to be introduced into the modelling of the fluxes equations. The TEB model subdivides the farm into three compartments the “Cultivated soil”, the “Cultures” and the “Animals”. The farm (studied system) exchanges materials fluxes with its environment subdivided, in his turn, into four compartments: The “Network waters”, the “Under ground” the "Atmosphere" and the "Third parties". The Ecobalance calculation period is of twelve months equivalent to an agricultural campaign and elements, taken into account at present, in the fluxes calculation are: the nitrogen (N), the phosphor (P), the potassium (K), the calcium (Ca), the magnesium (Mg), the chlorine (Cl), the sodium (Na) and the water (H20). Considering the specificities of the agro environmental problem in the studied context, the TEB global model was conceived as a general program which calculates the Ecobalance for the various taken elements and which offers the possibility to the user to focus the study on three sub models: The "Water" model (WEB), the "Nitrogen" model (NEB) and the "Salts" model (SEB). These three models allow to quantify and to analyse the materials fluxes respectively for "Water", "Nitrogen" and "Salts" on the farm or perimeter scale during the period calculation. The TEB model was tested, verified and validated on an optimised network of representative farms. In order to characterize better the studied domain and clarify more the main parameters and the inputs required by the model, this network was the object of a farming follow-up in the form of inquiries, local measures and analyses in the laboratory of samples of water and soil during three agricultural campaigns (2002-2003, 2003-2004 and 2004-2005). WEB sub model quantify a total of 15 fluxes between these compartments which are two types: "major fluxes" and "minor fluxes". The lysimétrique follow-up led in two contrasted farms allowed to conclude that this model is reliable with an error risk varying from 17 to 26 %. The irrigation water use efficiency remains globally weak with an average of 40 % exceeding 50 % only in 25 % of the farmers of the follow-up network while the irrigation valuation water rate in the production is 56 % on average. Therefore, it’s necessary to award more eco-advice efforts to improve the efficiency and rationalize the irrigation water use. The analysis of the model sensibility demonstrated that the varying fact of this rate of 5 % and 10 % leads a variation respectively of 17 % and 36 % on the final result represented mainly by the infiltration rate which is the vector of the nitrogenous pollution and the salts washing. Ultimately, the Web model is a tool that can be used by the manager to improve eco advice on recovery and rational use of water in agricultural irrigation. Similarly, the quantification of the indicators presented would help the manager make the right choice of crops for better utilization of irrigation water The NEB sub model allows quantifying 17 fluxes between the farm and its environment. The nitrogen potential lixiviation flux, main indicator of the pollution risk the groundwater, is on average 77,8 kg N ha-1 on the follow-up network scale with a maximum of 105 kg N ha-1 and a minimum of 35 kg N ha-1. The lysimetric follow-up curried out shows that 14 % and 13 % of the residual mineral nitrogen was respectively washed during the 2003-2004 campaign and the 2004 2005campaign. So it’s necessary to make more eco advice efforts in terms of nitrate fertilizers use. The analysis of sensibility of the model showed that the rate mineralization variation of 5 % and 10 % engendered a variation of the “nitrogen potential lixiviation” flux respectively of 10 and 19 %. The NEB sub model is very useful for the manager can learn about the potentially leachable inorganic nitrogen and the nitrogen fertilizer made unnecessarily by comparing the doses recommended. The SEB model quantifies 8 main fluxes mostly salts conveyed by irrigation waters of and washing salts. On 15 farms of the Ecobalance follow-up network, this “potentially washable salts” flux is about 4210 kg ha-1 on average with a variation coefficient of 52 %. The lysimetric follow-up realized showed that 18 % and 12 % of salts were respectively washed during the 2003-2004 campaign and the 2004-2005 campaign. Consequently, it’s required to think about rehabilitation measures within an interdisciplinary framework aiming at the durability preservation of the production systems. The analysis of sensibility of the model showed that the electric conductivity rate variation of 5 % and 10 % engendered a variation of the «washing salts" flux respectively of 8 % and 16 %. The analysis of SEB model results in relation with the NEB model in 10 farms studied showed that, given the quality of water and soil, the reasoning of the nitrogen should be reflected according to the timetable and efficiency of irrigation-dependent process of leaching of salts, but also according to the vegetative stage of the plant for better utilization of soil mineral nitrogen. Ultimately, a policy of eco efficient and appropriate advice to the problem of environmental study area inevitably involves consideration of three elements "water", "nitrogen" and "salts ". The TEB program could be one of the fundamental tools of policy All these results impose to think to technical support strategies to set up follow-up devices of the ground, to strengthen the capacities of taking targeted measures to validate and verify the developed models and cheer the work in interdisciplinary by developing the collaboration such as integrated projects aiming at the sustainability of the agricultural production systems. By more clarifying the parameters used as inputs, these models would become more successful and more reliable [less ▲]

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See detailRôle de RIPK3 dans la mort induite par la thérapie photodynamique
Fettweis, Grégory ULg

Master's dissertation (2011)

La protéine RIPK3 (Receptor-interacting protein 3) a été montrée comme étant un activateur clé de la nécrose, mais il a également été constaté qu’il pouvait induire l’apoptose. L’objectif de cette étude ... [more ▼]

La protéine RIPK3 (Receptor-interacting protein 3) a été montrée comme étant un activateur clé de la nécrose, mais il a également été constaté qu’il pouvait induire l’apoptose. L’objectif de cette étude est de comparer le profil de la mort induite par la thérapie photodynamique (PDT) médiée par l’acide 5-aminolévulinique (5-ALA) dans la lignée U2OS déficiente en RIPK3 et dans des U2OS où l’expression de RIPK3 était restaurée de manière stable. Pour ce faire, nous avons évalué la survie cellulaire ainsi que les paramètres d’apoptose, de nécrose et d’autophagie. De manière surprenante, la survie des U2OS RIPK3 positives traitées par 5-ALA-PDT a été augmentée comparé aux U2OS sauvages. De plus, la mort des cellules RIPK3 positives était diminuée lors d’un prétraitement au zVAD-fmk. Un clivage plus important de PARP et des caspase-3, -7, -8 et -9 a été constaté dans les cellules contenant RIPK3, pointant le rôle essentiel de l’apoptose dans la mort induite par 5-ALA-PDT. En parallèle, nous avons observé une augmentation du flux autophagique et de manière surprenante, un plus faible niveau de nécrose que dans les cellules U2OS Wild types. De plus, la nécrose induite en présence de RIPK3 était dépendante de RIPK1 au contraire de la nécrose induite dans les cellules U2OS RIP3 négatives. L’expression de RIPK3 a induit un changement de profil de la mort induite par 5-ALA-PDT, mais aussi une meilleure survie cellulaire face à ce traitement. Cet accroissement de la survie, dont l’observation constitue une première pourrait être dû au flux autophagique augmenté en présence de RIPK3. Enfin, le biais par lequel RIPK3 sensibilise les cellules à l’apoptose, et le mécanisme régissant la nécrose induite en absence de RIPK3 par la 5-ALA-PDT ne sont pas encore connus. [less ▲]

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See detailSelection, efficacy, ecological characterization and formulation of fungal control agents against water hyacinth [Eichhornia crassipes (Martius) Solms] in Mali
Dagno, Karim ULg

Doctoral thesis (2011)

Rice and irrigated orchards are considered as the most important food and economical sources in Mali, which watered from Niger River. However, stable productions of rice and orchards products have been ... [more ▼]

Rice and irrigated orchards are considered as the most important food and economical sources in Mali, which watered from Niger River. However, stable productions of rice and orchards products have been limited by many disease, insects, and weeds. Recently, water hyacinth infestation in river of Niger has increased drastically and as affected by the decrease of water flow due to clogging dams and irrigation work. Biological control of weeds is an alternative approach to chemical herbicide use, focusing on the use of native fungal to control or reduce the population of water hyacinth. From 2006 to 2007, 1000 samples consisting of infected parts of water hyacinth were collected from the River Niger (District of Bamako, Segou and Niono with GPS coordinates “12° 40’ N, 7° 59’ W” ; “13° 26’ N, 6° 15’ W” and “14° 15’ N, 5° 59’ W” respectively) in Mali. Fungal belonging to seven genera (116 isolates in all) were recovered from surface-sterilized water hyacinth parts with pronounced blight symptoms. On the basis of in vivo pathogenicity tests in which the diseased leaf area percentage was estimated visually and disease severity was estimated (by calculating a disease severity index), three isolates emerged as causing severe disease: Fusarium sp. isolate Mln799 (DS = 70%), Cadophora sp. isolate Mln715 (70%), and Alternaria sp. isolate Mlb684 (71%), identified respectively as Gibberella sacchari (Anamorph. Fusarium sacchari), Cadophora malorum, and Alternaria sp. This is the first report to highlight C. malorum as a candidate biocontrol agent for water hyacinth. Influence of ecological parameter, water activity (0.880 - 0.960aw modified par glycerol) and temperature (15-35°C) on viable conidia and mycelial growth rate of Alternaria sp. (isolate Mlb684), F. sacchari (isolate Mln799) and C. malorum (isolate Mln715) were evaluated. Germination and mycelial growth dropped as aw of the medium decreased. Results showed a significant effect of aw, temperature and their interaction on mycelial growth (P < 0.0001). Growth models for F. sacchari (isolate Mln799), C. malorum (isolate Mln715) and Alternaria sp. (isolate Mlb684) differed slightly, with R2 values of 93.40, 85.89 and 77.31% respectively. Mycelial growth models, no different between predicted and experimental values was observed. Results confirm the previous finding that aw has greater influence on growth of F. sacchari (isolate Mln799), C. malorum (isolate Mln715) and Alternaria sp. (isolate Mlb684) than temperature. Analyse of 5 target regions of isolate Mlb684 genome (18 and 28S ribosomal RNA genes, Elongation factor-1 alpha gene, calmodulin gene and actin gene) allowed identifying this isolate as new specie in Alternaria genus. The strain has been deposited under accession number MUCL 53159 in the Industrial Fungal & Yeast Collection (BCCMTM/MUCL, Belgium) and DNA sequences have been deposited in GenBank. We have named it “Alternaria jacinthicola Dagno & M.H. Jijakli”. It was the first sequenced of calmodulin gene reported in Alternaria genus. Water hyacinth, paddy and wheat substrates for mass production of these biocontrol agents were evaluated. Greater sporulation of C. malorum (isolate Mln715) was observed on water hyacinth substrate (4.08 x 107 spores ml-1) following by wheat (1.06 x 107 spores ml-1). Biocontrol efficacy of fungal isolates found to be enhanced with unrefined Carapa procera (L) oil and refined palm oil supplemented with soybean lecithin in greenhouse. Applying C. malorum (isolate Mln715) and A. jacinthicola (MUCL 53159 strain) in vegetable oil emulsion [Carapa procera (L) and palm oils] caused 87.02 to 93.13% of damage severity on water hyacinth 6 weeks after treatment. Field trials showed lower efficacy control than greenhouse tests. In host specificity tests, neither C. malorum isolate Mln715 nor Alternaria sp. isolate Mlb684 showed any pathogenicity towards any member of a panel of 17 crop plants of economic importance in Mali. [less ▲]

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See detailTest de bronchoprovocation à la métacholine chez le cheval : relation avec l’inflammation des voies respiratoires profondes
Frippiat, Thibault ULg

Master of advanced studies dissertation (2011)

The clinical examination and the ancillary tests used in clinical routine may be poorly characteristics in horses suffering from subclinical inflammatory airway disease or in clinical remission of ... [more ▼]

The clinical examination and the ancillary tests used in clinical routine may be poorly characteristics in horses suffering from subclinical inflammatory airway disease or in clinical remission of recurrent airway obstruction (RAO). Methacholine bronchoprovocation test, which is used for diagnosis of human asthma, has been used in some studies in horses, but none have examined his potential diagnostic interest. The objective of this study was to determine whether this test may represent an applicable and repeatable method for the diagnosis of an increased susceptibility to bronchospasm in horses, and whether there is a relationship between this test and the markers of inflammation in the bronchoalveolar lavage. Eight horses (6 with RAO history and 2 controls) were used. They underwent bronchoprovocation tests 2 times at 24h interval. They were then tested before and after 7 days of an environmental challenge. Simultaneously, bronchoalveolar lavages were done for the measurement of several inflammatory markers. The test has a good feasibility and significant repeatability. Dust exposure increased the bronchoreactivity, while it did not significantly affect other clinical and functional parameters or inflammatory makers. In the future, the bronchoprovocation test could therefore find its place in clinical practice for the detection of asymptomatic horses which are susceptible to develop bronchospasm in poorer environmental conditions. [less ▲]

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See detailGeometric optimization algorithms for linear regression on fixed-rank matrices
Meyer, Gilles ULg

Doctoral thesis (2011)

Nowadays, large and rapidly evolving data sets are commonly encountered in many modern applications. Efficiently mining and exploiting these data sets generally results in the extraction of valuable ... [more ▼]

Nowadays, large and rapidly evolving data sets are commonly encountered in many modern applications. Efficiently mining and exploiting these data sets generally results in the extraction of valuable information and therefore appears as an important challenge in various domains including network security, computer vision, internet search engines, bioinformatics, marketing systems, online advertisement, social networks, just to name a few. The rapid development of these modern computer science applications sustains an ever-increasing demand for efficient machine learning algorithms that can cope with large-scale problems, characterized by a large number of samples and a large number of variables. The research reported in the present thesis is devoted to the design of efficient machine learning algorithms for large-scale problems. Specifically, we adopt a geometric optimization viewpoint to address the problem of linear regression in nonlinear and high-dimensional matrix search spaces. Our purpose is to efficiently exploit the geometric structure of the search space in the design of scalable linear regression algorithms. Our search space of main interest will be the set of low-rank matrices. Learning a low-rank matrix is a typical approach to cope with high-dimensional problems. The low-rank constraint is expected to force the learning algorithm to capture a limited number of dominant factors that mostly influence the sought solution. We consider both the learning of a fixed-rank symmetric positive semidefinite matrix and of a fixed-rank non-symmetric matrix. A first contribution of the thesis is to show that many modern machine learning problems can be formulated as linear regression problems on the set of fixed-rank matrices. For example, the learning of a low-rank distance, low-rank matrix completion and the learning on data pairs are cast into the considered linear regression framework. For these problems, the low-rank constraint is either part of the original problem formulation or is a sound approximation that significantly reduces the original problem size and complexity, resulting in a dramatic decrease in the computational complexity of algorithms. Our main contribution is the development of novel efficient algorithms for learning a linear regression model parameterized by a fixed-rank matrix. The resulting algorithms preserve the underlying geometric structure of the problem, scale to high-dimensional problems, enjoy local convergence properties and confer a geometric basis to recent contributions on learning fixed-rank matrices. We thereby show that the considered geometric optimization framework offers a solid and versatile framework for the design of rank-constrained machine learning algorithms. The efficiency of the proposed algorithms is illustrated on several machine learning applications. Numerical experiments suggest that the proposed algorithms compete favorably with the state-of-the-art in terms of achieved performance and required computational time. [less ▲]

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See detailMultidisciplinary study of trophic diversity and functional role of amphipod crustaceans associated to Posidonia oceanica meadows
Michel, Loïc ULg

Doctoral thesis (2011)

Posidonia oceanica is the most abundant seagrass of the Mediterranean Sea. It can cover extensive areas with monospecific formations, called meadows. These meadows, whose extent is estimated to about 40 ... [more ▼]

Posidonia oceanica is the most abundant seagrass of the Mediterranean Sea. It can cover extensive areas with monospecific formations, called meadows. These meadows, whose extent is estimated to about 40,000 km2, are critical features of the Mediterranean coastal zones. Moreover, they shelter important biomass and biodiversity of vagile invertebrates. Among these invertebrates, amphipod crustaceans are, alongside gastropod mollusks and polychaete annelids, one of the dominant groups. Amphipods are key-features of other temperate seagrass systems. As they are generally primary consumers, they are important in the transfers of organic matter from producers to higher rank consumers. In addition, their grazing activity on the epiphytes that grow on the seagrasses influence the dynamics of the epiphytic cover, and therefore the functioning of the whole meadow as an ecosystem. However, the situation in Mediterranean Posidonia oceanica meadows is still unclear. In particular, several lacks of information limit the comprehension of actual trophic ecology of amphipods, and of the impact of their feeding activity on the meadow functioning. In this context, the main goal of this work was to enhance the knowledge of the trophic diversity and the functional role of amphipods associated to Posidonia oceanica meadows. To achieve this, we structured our research in three main tasks. For each of these tasks, we chose Calvi Bay (NW Corsica, France) as study site, and all sampling and experimentation was undertaken from the STARESO research station (University of Liège). The first task (chapter 3) was the study of the precise composition of the amphipod community structure at our study site, and its temporal variation at day/night and seasonal scale. Our results show that the fauna of Posidonia oceanica meadows of Calvi Bay is abundant and diverse. The density and the structure of the community were different in each season (November, March and June), probably in relation with meadow parameters such as foliar surface, epiphytic biomass and abundance of litter in the meadow. Moreover, day/night variations were very important. Most amphipods performed vertical migrations that could be a mechanism to avoid predation and/or competition for food and habitat. The comparison of three sampling techniques (hand-towed net, litter collection and light traps) yielded deeply different results, suggesting that each of them only collects a subset of a complex assemblage. Combination of several sampling methods is therefore advised to have a holistic and accurate view of the community. These faunistic data also allowed highlighting the most abundant and/or representative species of the studied community. These include Apherusa chiereghinii, Aora spinicornis, Dexamine spiniventris, Amphithoe helleri, Caprella acanthifera, Gammarella fucicola and Gammarus aequicauda. These species were therefore chosen as target species for the second task. The second task (chapter 4) was the assessment of the extent of interspecific trophic diversity among the studied community. This phenomenon could indeed be important to limit food competition. We tried to perform a full reconstruction of the diet of the dominant species of the community and to evaluate the contribution of each of the potential food items offered by the meadow (animal and vegetal epiphytes from the leaves, rhizomes and litter fragments, SPOM, BPOM, living and dead P. oceanica material). To have an accurate view of the dietary habits of the dominant species, we used a triple strategy based on the joint use of traditional methods (gut content examination) and trophic markers (stable isotopes of C & N, fatty acids). The combination of these three methods proved to be successful, as each method had specific strengths and weaknesses. Overall, results indicate that all dominant species relied on macroalgal epiphytes for a large part of their diet. Our insights were unfortunately limited by the poor discrimination between potential food items, due to high inter-source similarity. Considerable interspecific differences could nonetheless be highlighted, notably concerning preferences of epiphytes from leaves or litter fragments vs. epiphytes from rhizomes. In addition, most species had a mixed diet, and relied on several food items. None of the examined species seemed to graze on their seagrass host, but Gammarus aequicauda partly relied on seagrass leaf detritus. Contribution of microepiphytes (e.g. diatoms) to the diet of amphipods was apparently anecdotical. Our data also suggested the existence of a certain extent of intraspecific trophic diversity that should be taken into account for future work. In the third and final task (chapter 5), we aimed to put the data obtained in the first two parts of this study in the wider context of the functioning of the Posidonia oceanica meadow as an ecosystem. We used in vitro and in situ microcosms experiments to characterize the interaction between epiphytes and amphipods from a triple point of view (resource depletion, resource assimilation by the consumer and secondary production), and to understand how amphipod grazing could influence the dynamics of the epiphytic cover of the leaves of P. oceanica. Amphipod grazing had no effect on the total epiphytic biomass, or on the encrusting epiphytes’ biomass. However, all three taxa (A. chiereghinii, D. spiniventris and Gammarus spp.) consumed significant amounts (45 to 90 % of total biomass) of erected epiphytes, both vegetal and animal. This selective top-down control might influence the structure and biomass-specific productivity rates of the epiphytic cover. In addition, amphipod grazing caused an increase in N availability and residence time. Through epiphyte removal and N enrichment, amphipods could boost seagrass production. Overall, amphipods of Posidonia oceanica meadows could be seen as ecosystem engineers. Assimilation of the consumed epiphytes was clear for all taxa. However, the utilization of this biomass for secondary production was hard to measure, due to low survival rates of animals. In fine, by combining in situ sampling and microcosm experimentation, and trough the joint use of traditional and innovative techniques, we showed that feeding activity of amphipods influence their biotope through several effects, and that they could be pivotal items of Posidonia oceanica meadows. In doing so, we improved, to some extent, the understanding of these critically important, yet endangered ecosystems. [less ▲]

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See detailToxicocinétique du sélénium chez les tortues. Exposition in vivo chez Trachemys scripta scripta
Dyc, Christelle ULg

Master's dissertation (2011)

Le sélénium est un élément essentiel possédant un seuil « carence-excès » très étroit. L’étude toxicocinétique de cet élément, constitue une étape préliminaire importante à la compréhension des effets ... [more ▼]

Le sélénium est un élément essentiel possédant un seuil « carence-excès » très étroit. L’étude toxicocinétique de cet élément, constitue une étape préliminaire importante à la compréhension des effets néfastes qu’il est susceptible de causer chez les populations de reptiles. Une expérimentation impliquant 130 tortues de Floride juvéniles (Trachemys scripta scripta) a été réalisée. Le groupe contrôle a été alimenté avec une nourriture de base, alors que les deux conditions expérimentales ont reçu une nourriture supplémentée avec 64 µg/g et 134 µg/g de séléno-L-méthionine (PS), pendant huit semaines. L’accumulation du Se a été mesurée dans le foie, les reins, le muscle, la peau, les écailles, la carapace et le sang, ce qui a permis d’observer que le transfert trophique du sélénium se réalisait de manière dose-dépendante. Durant quatre semaines supplémentaires, une cinétique d’élimination du Se a également pu être observée. De plus, la concentration en Se dans le sang, dans la carapace et dans la peau est apparue fortement corrélée à celle des tissus internes. Cette observation semble intéressante pour la mise en place d’un biomonitoring peu invasif des tortues dans leur milieu naturel. Les concentrations toxiques auxquelles les tortues ont été soumises n’ont pas permis de détecter d’effets néfastes au niveau de la croissance, de la prise alimentaire et de la survie des tortues. [less ▲]

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See detailResidency Patterns, Abundance and Social Composition of Bottlenose Dolphins (Tursiops truncatus) in Bahía San Antonio, Patagonia, Argentina
Vermeulen, Els ULg

Master of advanced studies dissertation (2011)

Residency patterns, abundance and social composition of bottlenose dolphins (Tursiops truncatus) were assessed during 2008-2010 in Bahía San Antonio (BSA), Patagonia, Argentina. A total of 462.3 survey ... [more ▼]

Residency patterns, abundance and social composition of bottlenose dolphins (Tursiops truncatus) were assessed during 2008-2010 in Bahía San Antonio (BSA), Patagonia, Argentina. A total of 462.3 survey hours resulted in 80.7 contact hours with in total 107 dolphin groups. Data indicated that dolphins spend most of their time resting, feeding and travelling in BSA, although their time-budget changed over the different seasons. As such, dolphins increased their time feeding and socializing during winter and spring, whereas during summer they spent up to 46% of their time diving, a behaviour presumably associated with a tail out/peduncle-dive foraging strategy. Dolphin groups had a median size of 4 individuals ranging between 1 and 40. Group size seemed to vary significantly over the different seasons and behaviours, with groups being larger during winter and during socializing and feeding. Group size was further positively correlated with the presence of calves. A total of 63 dolphins were individually identified in the bay and re-identified up to 35 days. Of these, 57% could be regarded as resident in the area (year-long or seasonally), including all mother and calf pairs. Using the closed time heterogeneity model (Mth), and accounting for the proportion of unidentifiable individuals, calculations resulted in a maximum corrected abundance estimate of 97 and 83 individuals during winter, and a minimum abundance of 34 and 38 individuals during autumn of 2009 and 2010 respectively. At all times, between 25% and 68% of the population consisted out of unidentifiable individuals (juveniles and calves) depending on the season. Results further revealed that bottlenose dolphins in BSA associated at random and that the entire community existed out of two levels of casual acquaintances. Data presented herein suggest that the shallow and protected waters of BSA support a resident community of bottlenose dolphins, between 35 to 97 individuals depending on the season, living in a fission-fusion society in which companionships frequently change. It was further suggested that dolphins specifically use BSA to rest and feed, and that the region is preferred by females to give birth and raise their young, with a possible increased calving period during winter and spring based on an increasing prey availability. [less ▲]

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See detailDéveloppement d’approches complémentaires pour limiter la transmission virale par les pucerons dans la Province du Shandong
Bosquée, Emilie ULg

Master's dissertation (2011)

Nowadays, in China, the control of aphids lies on the systematic use of synthetic insecticides. A socio-economical analysis of rural households’ structure in the Shandong province was carried out. The ... [more ▼]

Nowadays, in China, the control of aphids lies on the systematic use of synthetic insecticides. A socio-economical analysis of rural households’ structure in the Shandong province was carried out. The latter highlighted the farmers’ unawareness of the chemicals’ harmful effects on the environment and on human health. This observation led to some research aiming at the development of new alternative methods that would be efficient for Chinese producers. Within this context of biological control against aphids and their virus transmission (Potato virus Y (PVY), Cucumber mosaic virus (CMV) et Potato Leaf Roll Virus (PLRV)), three semiochemical substances namely (E)-β-farnesene (EBF), cis-3-hexenyl acetate, garlic extract and peas intercropping were separately tested. Yellow traps were used and the treatments were applied on potatoes and courgettes fields. No significant difference is observed between the different treatments. However, a tendency for cultural association is showed. Another kind of biological control was envisaged: the use of lectins. In this study, the effects of three glycoproteins on the virus transmission of three non-persistant viruses were tested in laboratory on Myzus persicae via the use of artificial diets. The glycoproteins used were Canavalia ensiformis agglutinin (ConA), Galanthus nivalis agglutinin (GNA) and wheat germ agglutinin (WGA) as for the viruses; PVY, CMV and TuMV (Turnip Mosaic Virus). An interference between GNA and all viruses was observed. In addition, a competition between WGA and two viruses i.e. CMV and TuMV was highlighted. In consequence, the two latter lectins are considered as promising proteins. In order to share the results of this study with Chinese farmers, simplified technical specifications on the insect fauna of vegetable crops grown previously, the hazard of pesticides and on the tested alternative methods of control were written and distributed. [less ▲]

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See detailCaractérisation hydrogéologique du bassin du Lilot
Briers, Pierre ULg

Master's dissertation (2011)

Le Lilot, ruisseau de la région de Marchin (province de Liège) s’écoule majoritairement sur des formations givetiennes karstifiées. Ce contexte laisse supposer une forte vulnérabilité de l’aquifère ... [more ▼]

Le Lilot, ruisseau de la région de Marchin (province de Liège) s’écoule majoritairement sur des formations givetiennes karstifiées. Ce contexte laisse supposer une forte vulnérabilité de l’aquifère. Cependant, cette vulnérabilité n’est pas avérée car il faut encore qu’un volume suffisant de polluant s’infiltre et que le taux de renouvellement de l’aquifère ne puisse diluer cette contamination. De plus, rien n’indique que les eaux qui s’infiltrent au niveau des pertes rejoignent la nappe aquifère. L’objectif de ce travail est d’effectuer une caractérisation hydrogéologique du bassin et d’étudier les interactions entre les eaux de surface et les eaux souterraines. Cela a été réalisé à l’aide de divers outil tels qu’une étude du cycle hydrologique et un calcul de bilan, des profils débimétriques et physicochimiques du cours d’eau et un essai de traçage. [less ▲]

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See detailComparaison histologique et comportementale de différentes souches de souris après un épisode d’ischémie cérébrale
Fassotte, Ludivine ULg

Master's dissertation (2011)

L’ischémie cérébrale, qui correspond à une interruption du flux sanguin causée par l’obstruction d’une artère cérébrale, est occasionnée dans plus de 80% des AVCs humains. Cette maladie neurologique est ... [more ▼]

L’ischémie cérébrale, qui correspond à une interruption du flux sanguin causée par l’obstruction d’une artère cérébrale, est occasionnée dans plus de 80% des AVCs humains. Cette maladie neurologique est la seconde cause de mortalité dans les sociétés industrialisées et son impact est lourd sur les survivants. En effet, elle génère des déficits fonctionnels subsistant pendant des mois, voire des années. Ce travail s’inscrit dans la perspective de développement d’un traitement permettant une récupération fonctionnelle de ces déficits par la recherche de techniques permettant de mimer un AVC humain sur différentes souches de rongeurs. Le présent travail consiste en la mise en place d’une batterie de tests comportementaux permettant l’évaluation à court et à long terme des déficits sensorimoteurs, comportementaux et cognitifs causés par une ischémie cérébrale expérimentale de 30 minutes induite par la technique d’occlusion de l’artère cérébrale moyenne (MCAo) à droite. Dans cette perspective, deux souches murines couramment utilisées en laboratoire, 129S2/SvPas et C57Black6J ont été comparées. Une semaine puis trois semaines après l’opération, les capacités sensorimotrices des animaux sont évaluées à l’aide du rotarod, du pole test, du test d’agrippement tandis que l’activité locomotrice et l’anxiété sont mesurées dans un open field. Après un mois, l’endurance et la motivation sont testées par un programme de FR progressif alors que la flexibilité cognitive est évaluée à l’aide du programme du reversal learning. Au terme de l’évaluation comportementale, le cerveau des animaux est prélevé et l’étendue de la lésion cérébrale est évaluée à l’aide d’une révélation immunohistochimique utilisant le marquage anti-neuronal NeuN. Les résultats témoignent d’un effet significatif de l’ischémie chez la souche C57 sur les capacités sensorimotrices des animaux (rotarod et locomotion). Les résultats au FR progressif montrent qu’une ischémie de 30 minutes altère l’endurance des animaux lorsque le nombre d’appuis demandé est élevé. De même, un trouble des fonctions exécutives est également observé (passage d’un comportement à un autre). La lésion occasionnée par l’ischémie touche le striatum dorsolatéral chez les deux souches ainsi qu’une portion plus moins étendue du cortex cérébral dans le cas de la souche C57. L’étendue plus ou moins importante de la lésion est liée à l’anatomie vasculaire cérébrale qui est variable d’une souche à l’autre. Puisque le cortex moteur n’est pas affecté, les troubles observés sont probablement liés à la lésion du striatum, une portion du cerveau qui est étroitement connectée avec le cortex moteur. A l’issue de ces expériences, l’utilisation de la souche C57 semble être plus appropriée à l’étude de l’ischémie cérébrale transitoire chez la souris que la souche 129S2. Le présent travail montre que l’établissement d’une batterie de tests comportementaux sensibles à l’ischémie doit comporter à la fois des tests sensorimoteurs afin de déceler des troubles transitoires tels que la coordination motrice et l’endurance. Une telle batterie doit également comporter des tests cognitifs détectant des déficits subsistant à long terme tels que les troubles de la fonction exécutive. La sélection d’un modèle animal le plus approprié ainsi que la mise en place d’une telle batterie de tests permettront idéalement de corréler les déficits observés et les structures nerveuses impliquées dans les fonctions touchées par l’ischémie cérébrale. Dès que ces bases auront été posées, de nouveaux traitements appropriés pourront alors être testés. [less ▲]

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See detailModélisation d'évènements rares à l'aide de distributions non normales : application en finance avec la fonction sinh-arcsinh
Hambuckers, julien ULg

Master's dissertation (2011)

In 2008, the financial crisis put forward the relative inaccuracy of the market risk forecasting models in the financial industry. In particular, extreme events were shown to be regularly underestimated ... [more ▼]

In 2008, the financial crisis put forward the relative inaccuracy of the market risk forecasting models in the financial industry. In particular, extreme events were shown to be regularly underestimated. This problematic, initially developed in the seminal work of Mandelbrot (1963), is mainly due to financial models using the normal law while empirical evidence show strong leptokurticity in financial time series. This stylized effect is particularly damaging the forecasting of indicators like Value-at-Risk (VAR). In this study, we try to tackle problem by testing a newly-developed probability distribution, never used in finance: sinh-arcsinh function. By creating different datasets from non-parametric and GARCH models, we adjust common functions (normal, t location-scale, GED, gen. hyperbolic) and sinh-arcsinh function on the data. We show that, regarding the leptokurtic datasets extracted from the DJA and the NIKKEI 225, the sinh-arcsinh function performs a better adjustment than any other function tested. We also tested simple VAR models using normal laws, Student’s t or sinh-arcsinh functions, to assess the operational efficiency of the sinh-arcsinh function. We show that models using sinh-arcsinh functions provide more accurate and better in-sample and out-of-sample VAR forecasts than any other model using the normal laws. [less ▲]

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See detailArticle de régulation
Scheffers, Patricia ULg

Master's dissertation (2011)

Les outils pédagogiques (*) mis en place dans le cadre du cours d'atelier de projet d'architecture de 3e Bachelier sont-ils de nature à favoriser l’autonomisation de l'étudiant et à en rendre compte dans ... [more ▼]

Les outils pédagogiques (*) mis en place dans le cadre du cours d'atelier de projet d'architecture de 3e Bachelier sont-ils de nature à favoriser l’autonomisation de l'étudiant et à en rendre compte dans le cadre du développement de la compétence visée ? (*) Abstract, journal de bord, fiches d'auto-évaluation, plannings [less ▲]

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See detailEtude protéomique de l'incidence d'une hypertriglycéridémie sur le métabolisme hépatique de la souris
Ehx, Grégory ULg

Master's dissertation (2011)

L’hypertriglycéridémie est une pathologie largement répandue chez l’homme sédentarisé. Elle se définit comme un taux plasmatique de triglycérides (TAG) anormalement élevé (supérieur à 200 mg/dl). La ... [more ▼]

L’hypertriglycéridémie est une pathologie largement répandue chez l’homme sédentarisé. Elle se définit comme un taux plasmatique de triglycérides (TAG) anormalement élevé (supérieur à 200 mg/dl). La souris transgénique HuApoC-III est un animal modèle idéal pour l’étude de l’hypertriglycéridémie indépendamment des effets confondants qui y sont généralement associés (en particulier l’obésité et la résistance à l’insuline). En effet, elles sont hypertriglycéridémiques mais ne sont ni obèses ni résistantes à l’insuline. Dans la continuité d’une étude des adaptations mitoprotéomiques hépatique à une hypertriglycéridémie sévère (taux de TAG supérieur à 500 mg/dl) récemment menée par notre laboratoire, nous avons caractérisé par une technique de protéomique comparative, le 2DDIGE, les adaptations protéomiques de la membrane interne mitochondriale et du protéome cellulaire à ce même type d’hypertriglycéridémie, chez la souris HuApoC-III. Comme prédit lors de notre étude antérieure, le protéome de la membrane interne s’est avéré ne présenter aucune modification de sa composition entre les souris HuApoC-III et sauvages. Comme il a été rapporté que les souris HuApoC-III présentent une vitesse de respiration mitochondriale à l’état III sur succinate similaire à celle des souris sauvages, cette invariance de la composition protéique de la membrane interne pourrait refléter des altérations de sa composition lipidique ou de sa structure. L’analyse du protéome cellulaire total a permis de confirmer l’augmentation de la capacité du catabolisme des acides aminés et de la glycolyse suggérée par nos résultats antérieurs. Cette augmentation, accompagnée de l’augmentation de la capacité de la β- oxydation également décrite antérieurement, permettrait d’augmenter le taux de production d’acétyl-CoA, de glycérol-3-phosphate et d’ATP fin de supporter la production élevée de TAG des hépatocytes des souris HuApoC-III. Cette analyse a par ailleurs révélé que les hépatocytes des souris HuApoC-III présentent un stress oxydatif cytoplasmique, une probable accumulation de fer intracytoplasmique et une prolifération accrue. Ce stress oxydatif pouvant induire des lésions cellulaires et tissulaires ainsi que l’inflammation du foie, nous proposons que les souris HuApoC-III présentent une fibrose hépatique. [less ▲]

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See detailL’impact de la mobilité internationale sur le projet de carrière et la construction de l’identité professionnelle des cadres internationaux à la lumière des ancres de carrière et des typologies identitaires : Analyse comparative des motivations personnelles et professionnelles des cadres en mobilité internationale
Gérard, Julie ULg

Master's dissertation (2011)

Fondée sur une recherche empirique menée auprès de trente-trois cadres en situation de mobilité internationale, cette étude analyse l’impact de la mobilité internationale sur le projet de carrière et la ... [more ▼]

Fondée sur une recherche empirique menée auprès de trente-trois cadres en situation de mobilité internationale, cette étude analyse l’impact de la mobilité internationale sur le projet de carrière et la construction de l’identité professionnelle des cadres internationaux, en s’appuyant sur la théorie des ancres de carrière de Schein (1978, 1990) et la théorie des stratégies identitaires de Pierre (2003). Sur la base du récit de vie de ces trente-trois cadres, nous avons étudié leurs motivations personnelles et professionnelles afin de dresser une typologie nuancée et circonstanciée de leur stratégie d’identification. [less ▲]

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See detailContribution to the study on sound production in clownfishes (Perciformes, Pomacentridae): a multidisciplinary approach
Colleye, Orphal ULg

Doctoral thesis (2011)

Clownfishes (Amphiprion spp.) are brightly colored fishes that are members of the Pomacentridae family. They are well known for their mutualistic relationship with tropical sea anemones. These fishes live ... [more ▼]

Clownfishes (Amphiprion spp.) are brightly colored fishes that are members of the Pomacentridae family. They are well known for their mutualistic relationship with tropical sea anemones. These fishes live in social groups in which there is a size-based dominance hierarchy. In this structure where sex is socially controlled, agonistic interactions are numerous and serve to maintain size differences between individuals adjacent in rank. Several studies have reported that vocalizations are associated with agonistic interactions but precise data are lacking and further investigations are needed. The nature of the sound-producing mechanisms also remained unresolved, only resting on few assumptions. Thereby, the main aim of the present thesis is (1) to determine the fundamental components of the acoustic communication in clownfishes, and (2) to explain the mechanisms of sound production. In order to achieve these objectives, the research has been divided into three different axes. Firstly, the study of the acoustic behaviors shows that no acoustic signal is associated with reproductive activities in clownfishes. Sound recordings during agonistic interactions indicate that these fishes produce two types of sounds. Aggressive sounds are produced during chases and threat displays while submissive (or head shaking) sounds are emitted in reaction to aggressive acts by dominant. Both types of sounds show size-related intraspecific differences in dominant frequency and pulse duration: smaller individuals produce higher frequency and shorter duration pulses than larger individuals, and inversely. Consequently, these sonic features might be useful cues for individual recognition and maintenance of cohesion within the group. Secondly, the study of the sound-producing mechanism highlights that aggressive sounds are initiated by buccal jaw teeth snapping caused by rapid mouth closure attributed to a sonic ligament. It appears that the swimbladder does not function as a resonator that amplifies and changes the quality of sounds. This structure is a highly damped sound source prevented from prolonged resonant vibrations. On the other hand, the rib cage might be the major acoustic radiator and its resonant properties might explain the size-related variations observed in pulse duration and dominant frequency. Thirdly, the comparison of aggressive sounds among fourteen clownfish species indicates that the same relationship between fish size and both dominant frequency and pulse duration is spread over the entire group (i.e. tribe Amphiprionini). These results highlight all species use a highly conservative mechanism of vocalization. Pulse period appears to be the most variable acoustic feature and could be involved in species-specific recognition, as well as pulse duration and dominant frequency in a lesser extent through their relationship with body size. Although sound production appears to be restricted to some agonistic behaviors, these sounds seem to constitute an integral part of the peculiar way of life of clownfishes. The aggressive and submissive sounds would also result from two different mechanisms.   [less ▲]

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See detailREGULATION DE L'EXPRESSION ET DE LA REPLICATION DU VIRUS T-LYMPHOTROPE HUMAIN DE TYPE I (HTLV-1) PAR LE COMPLEXE MINICHROMOSOME MAINTENANCE 2-7 (MCM2-7)
Barez, Pierre-Yves ULg

Master's dissertation (2011)

First human retrovirus discovered, HTLV-1 infects approximately 20 million individuals worldwide. HTLV-1 is the etiological agent of adult T-cell leukemia and a neurodegenerative disorder called HAM/TSP ... [more ▼]

First human retrovirus discovered, HTLV-1 infects approximately 20 million individuals worldwide. HTLV-1 is the etiological agent of adult T-cell leukemia and a neurodegenerative disorder called HAM/TSP (HTLV-1 associated myelopathy/Tropical spastic paraparesis). The MCM2-7 complex seems to play a key role in the biology of viruses, such as EBV (Epstein-Barr virus), KSHV (Kaposi’s sarcoma associated virus) or Influenza. This is also the case for HTLV-1 virus because we revealed the recruitment of MCM2-7 onto the viral promoter. The role of this interaction does not pertain to viral replication but is involved in transcriptional regulation. In fact, overexpression of MCM3 increases Tax transactivation activity dependently on Tax/MCM3 interaction and MCM3 carboxy-terminal domain. Finally, our observations indicate that MCM3 is likely required for Tax nuclear shuttling. This work thus gives insights into new mechanisms by which Tax ensures the viral persistence and leads to the development of HTLV-1 associated diseases. [less ▲]

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See detailRôles des hydrocarbures dans le comportement agrégatif de la coccinelle asiatique, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae)
Fassotte, Bérénice ULg

Master's dissertation (2011)

In order to protect themselves against cold and to survive through the winter, the Asian ladybeetle Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) forms large aggregates inside dwellings to ... [more ▼]

In order to protect themselves against cold and to survive through the winter, the Asian ladybeetle Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) forms large aggregates inside dwellings to overwinter. In this work, the implication of hydrocarbons on the aggregative behaviour of this invasive species has been examined to understand the mechanisms involved in this particular phenomenon. The evolution of non-volatile compounds, proved to be used by H. axyridis in this phenomenon, on one hand to guide individuals to the aggregate ("trail") and on the other hand, to ensure the cohesion of the cluster ("aggregation blend"), has been studied by performing chromatographic analyses and behavioural tests. The results show that the composition of the trail deposited by individuals, and its biological activity on ladybirds, change over months. However, the change in ladybirds’ response towards these trails is not due to a modification of blend attractiveness but well to a change in the physiological state of ladybugs. Furthermore, the effect of photoperiod on the induction of that hivernation state was tested. It was highlighted that only a short photoperiod could not be responsible for the aggregation state of H. axyridis. Then, the maturing process of the aggregation blend was studied, demonstrating that saturated hydrocarbons were more persistent and suggesting their use by ladybirds to join the same aggregation sites year after year. Moreover, it turned out that cuticular hydrocarbons, as well as thigmotaxis, play a role in the aggregation behaviour of H. axyridis. However, this second factor is involved to a lesser extent. [less ▲]

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See detailContribution à la conservation de la flore cupro-cobalticole endémique du Katanga (R.D.C.) : Conservation en banque de graines et régénération d'espèces métallicoles
Boisson, Sylvain ULg

Master's dissertation (2011)

Metallophytes are plants that represent the biodiversity of metal-rich soils. Some of them are able to accumulate high metal concentrations: metal hyperaccumulators plants. In Katanga (RD Congo), 32 ... [more ▼]

Metallophytes are plants that represent the biodiversity of metal-rich soils. Some of them are able to accumulate high metal concentrations: metal hyperaccumulators plants. In Katanga (RD Congo), 32 species have been identified as copper-cobalt endemic but mining activities are still a threat to outcrop ecosystems. We must characterize native environmental parameters (realized niche) and the full range of environmental conditions in culture (fundamental niche) to conserve, preserve and restore these ecosystems. Six representative species of the natural copper gradient were selected after soil-species data analyses (Crepidorhopalon perennis, Crotalaria cobalticola, Gladiolus ledoctei, Haumaniastrum robertii, Lopholaena deltombei and Sopubia mannii). The study determined their behavior (germination, survival) and their development (vegetative measures) on one group of natural soil (from three copper gradients of Fungurume V hill), two groups of artificially contaminated soils with incremental doses (copper sulfate and copper hydroxycarbonate: 500, 2000 and 5000 mg.kg-1) and one uncontaminated soil (control) by two types of plant establishment (direct seeding and transplant from Petri dishes). The results depend on species habitat and show that four of these species can grow on uncontaminated soil in the early stages of growth. In addition, the seed bank (in Faculty of Agronomy - University of Lubumbashi) management (cleaning, updating and germination tests of accessions) was maintained using standard methods. The results of germination tests demonstrated the effectiveness of some conservation methods and helped to provide recommendations for the methodology. [less ▲]

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See detailMise en place de différentes stratégies visant à favoriser l’approche « push-pull » pour le contrôle des pucerons en cultures maraîchères dans l’est de la Chine
Chevalier Mendes Lopes, Thomas ULg

Master's dissertation (2011)

The Chinese farmers apply a lot of pesticides in their vegetable crops. This situation, due to the socio-economic context of the rural population of the country, affects the food security. This work aims ... [more ▼]

The Chinese farmers apply a lot of pesticides in their vegetable crops. This situation, due to the socio-economic context of the rural population of the country, affects the food security. This work aims to study alternatives to the intensive use of synthetic pesticides, namely by the establishment of “push-pull” strategies, in courgettes and potato fields. We used three semiochemicals, the (E)-β-farnésène, the (Z)-3-Hexenyl acetate and a garlic extract and intercropping with pea. The effect of these treatments in the populations of aphidiphagous beneficial insects was determined by five weeks of insect trapping and observations on the plants. The results indicate that none of the modalities has a significant effect on the populations of beneficial insects and aphids. However, we observed some trends, especially with the (E)-β-farnésène in the courgettes fields. In addition, information sheets were made to inform and raise awareness of the Chinese farmers about the use of pesticides and the role of beneficial insects in the control of aphid populations. [less ▲]

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See detailLa place de l'identité dans la politique étrangère. Le cas de la Turquie dans la période de pos-11 septembre 2001
Arslan, Nevzat ULg

Doctoral thesis (2011)

Il est question, dans ce travail, de découvrir les variables qui jouent un rôle dans l'orientation et dans la détermination de la politique étrangère turque. Il s'agit donc de s'intéresser aux variables ... [more ▼]

Il est question, dans ce travail, de découvrir les variables qui jouent un rôle dans l'orientation et dans la détermination de la politique étrangère turque. Il s'agit donc de s'intéresser aux variables causales découlant de la politique intérieure de la Turquie. Ainsi est évaluée l'importance des variables individuelles, institutionnelles, gouvernementales et systémiques dans la détermination des idées et des intérêts défendus par les différents acteurs internes. Adoptant une approche constructiviste des relations internationales, cette étude consiste, d'une part, en une description de l'identité nationale de l'État turc et de l'autre en une explication de la redéfinition de cette identité par une nouvelle idéologie, défendue par une nouvelle classe dirigeante. Nous nous sommes penchés sur les valeurs et les identités nationales qui ont contribué à façonner les conceptions et les priorités de la politique étrangère turque. Ainsi, l'approche théorique choisie doit tenir compte de ces divers facteurs, qui exercent une influence sur la formulation des intérêts nationaux. [less ▲]

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See detailContribution à la recherche et à l’étude d’améliorants de panification
Dubrowski, Thomas ULg

Master's dissertation (2011)

This work takes place in the current trend aiming to find new substances that, once added to the formulation of bread, improve its characteristics. To do this, a homologous series of three emulsifiers ... [more ▼]

This work takes place in the current trend aiming to find new substances that, once added to the formulation of bread, improve its characteristics. To do this, a homologous series of three emulsifiers, synthesized from glucuronic acid on which were grafted hydrocarbon chains of different lengths (from 14 to 18 carbon atoms), was obtained by glycosylation. The purification of these three surfactants is also described as feasible, with an almost complete separation of the two anomers obtained through this synthesis. Then these three synthesized products were applied to bakery by conducting laboratory tests (farinograph, alveograph) followed by micropanification tests in real conditions. In order to compare their results, two commercial references (DATEM and SSL) have also been used. It appears that none of the alkyl glucuronolactone possesses a “dough strengthener” effect while a “crumb softener” effect was noted (P < 0.05) for GlcA-O-C14 and -C16 in comparison with the “control”, with in the latter case, a greater decrease of firmness than with SSL, already popular for its action. The role of these molecules on staling was also analyzed and it seems that they slow down the hardening of bread after 27 h (P < 0.05) more than the commercial references, whereas after 48 h, only GlcA-O-C18 retains an advantage against the formulation without any emulsifier, even if it is no longer significant. [less ▲]

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See detailDa Alessandro ai Theoi Adelphoi. Fondazione e legittimazione della dinastia tolemaica, tra IV e III secolo a.C.
Caneva, Stefano ULg

Doctoral thesis (2011)

The research focuses on the first century of the Macedonian rule over Egypt in order to study how the Ptolemies had their power legitimated in Africa and in the broader Mediterranean context. Literary ... [more ▼]

The research focuses on the first century of the Macedonian rule over Egypt in order to study how the Ptolemies had their power legitimated in Africa and in the broader Mediterranean context. Literary sources (both prose and verse, in Greek and Egyptian language), inscriptions, papyri, and iconography are used to set an interdisciplinary approach to the topic. Major attention is paid to the social contexts where ideological motifs originate and spread; to the link between media, genres and consensus making; to the genealogy and development of specific legitimating themes and their later incorporation in learned traditions or local identities. Section I: From Alexander to the Ptolemies. Chapter I: Alexander in Egypt: focus is on the role of Siwah in the perspective of the Greek, Macedonian, and Egyptian legitimation of Alexander's power in Egypt; particular attention is paid to how legitimating traditions are used and reshaped to the purposes of broadening the limits of Macedonian kingship, depicting Alexander as a Greek hero, interpreting Egyptian kingship for Greeks and Macedonians and naturalizing Alexander as a Pharaoh. Chapter II: In the name of Alexander: how Ptolemy adapted to the hierarchy of proximity to the king to legitimate his power in Egypt and finally to establish a new dinasty; main topics are the use of Alexander's body in the historical context of the succession and in the local tradition of Alexandria; the historical events of the last decades of IV century are considered from the perspective of the development of legitimating themes, such as the political allegiance to Alexander, the right of conquest, the use of marriage diplomacy. Section II: The Political Use of Religious Festivals under Ptolemy II. Chapter III: Sources and Historical Problems concerning the Ptolemaia: sources on the Ptolemaia, Pentaeteris and Callixeinus' report in Athen. V are discussed to study dynastic festivals during Ptolemy II’s reing. Chapter IV: Anatomy of a Festival: The Grand Procession of Ptolemy II: focus is on the making of an historical and mythic legitimating past through the scenes in the procession. Section III: Patterns of Female Power: The Case of Arsinoe II Chapter V: Shaping Female Power: Arsinoe II as a Queen: Arsinoe II's career and political legacy are discussed to offer a gender-related evaluation of her role as a queen in both Greco-Macedonian and Egyptian traditions. Chapter VI: Female Ruler Cults. Arsinoe in Early Hellenistic Context: the analysis combines court poetry, iconography and documentary texts to study the cults for Arsinoe both as a member of the Theoi Adelphoi and as an individual goddess, the Philadelphos. Arsinoe's case is then discussed in the broader perspective of female ruler cults in early Hellenism. [less ▲]

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See detailCaracterización del producto cerámico en las comunidades neolíticas de mediados del V milenio Cal BC: El valle del Éufrates y el valle del Khabur en el Halaf final (Siria).
Gomez Bach, Ana Maria ULg

Doctoral thesis (2011)

The characterization of pottery production in the mid-sixt millennium cal BC in Neolithic communities: the Euphrates valley and Khabur basin in Late Halaf. SUMMARY The characterization of pottery ... [more ▼]

The characterization of pottery production in the mid-sixt millennium cal BC in Neolithic communities: the Euphrates valley and Khabur basin in Late Halaf. SUMMARY The characterization of pottery production in the mid-sixth millennium cal BC contexts in the Middle East arises from the need to understand how consolidated agricultural and pastoral communities of the Fertile Crescent were structured and organized. This chrono cultural period is embodied in an archaeological record of great interest in order to identify the different economic, social and symbolic responses at the final moment of the so-called Halaf culture. The opportunity to study the pottery assemblages from two sites and two regions, such as the Euphrates valley and the valley of Khabur, with new material from Tell Halula (16,668 sherds) and Chagar Bazar (21,194 sherds), allowed us to study and apply the same methodology to both sets from the very beginning of fieldwork. The analysis of 37,882 fragments from a comprehensive perspective and by using archaeometric techniques (chemical, petrographic and PIXE analysis) as well as morphometric and basic techno functional characterization analysis set new guidelines on the archaeological potential of these sets. Drawn up from Archaeology and Materials Science, this contribution has its methodological framework focused on rebuilding the chaîne operatoire. This reconstruction has allowed us to study and isolate two assemblages and to outline the existence of different socio economic practices, some of which had clear regional links and a strong substrate, but above all with basic subsistence practices which can be addressed from the ceramic product itself. Likewise, the specific chronological framework provided by new radiocarbon dates of both sites, which are between 5600-5300 cal BC, enables not only to characterise these productions but also to arise new questions to understand the interaction mechanisms between communities; mechanisms that cover from basic subsistence practices, i.e. the handling and processing of food and products, to mechanisms which regulate and structure the group. [less ▲]

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See detailDifférenciations sociospatiales et gouvernance municipale dans les banlieues de Beyrouth : à travers l'exemple de Sahel AlMatn AlJanoubi et des municipalités de Chiyah, Ghobeiri et Furn AlChebbak
Farah, Jihad ULg

Doctoral thesis (2011)

La thèse s’inscrit dans le débat sur une des “grandes questions urbaines contemporaines”: comment dans la multiplication des projets individuels et collectifs de plus en plus fragmentés se construit la ... [more ▼]

La thèse s’inscrit dans le débat sur une des “grandes questions urbaines contemporaines”: comment dans la multiplication des projets individuels et collectifs de plus en plus fragmentés se construit la ville d’aujourd’hui? Dans un contexte d’étalement urbain continu et de crise des “grands récits” de la modernité, l’individu comme le groupe connaît de plus en plus de difficultés à trouver sa place, son “lieu”, en ville. La recherche de l’entre-soi et l’altérité devient de plus en plus importante dans cette quête. La thèse revient sur les différents concepts traitant des différenciations sociospatiales en ville (ségrégation, marginalisation, relégation, fragmentation). Elle remarque que ces concepts favorisent une lecture systémique de la réalité urbaine où les éléments factoriels économiques, culturels et politiques ont un rôle central dans l’explication. Tout en se mettant dans la continuité de ces travaux, la thèse privilégie une lecture se basant sur trois entrées: - La crise de citoyenneté urbaine (crise de définitions de la ville, de ses limites, de ses citoyens, de leurs droits et surtout de sa gouvernance) comme principale grille explicative - Le local. Ce dernier étant d’une part l’échelle où ces différenciations sociospatiales sont les plus manifestes, et d’autre part car c’est à cette échelle que les phénomènes systémiques doivent se “redéfinir” en s’inscrivant dans le contexte. - Les périphéries et les banlieues où la cirse de citoyenneté est plus nette et où les acteurs locaux – dans un milieu à la recherche de sens, et en continuelle redéfinition – cherchent à avoir plus d’emprise sur leur milieu direct. Dans ce contexte la thèse avance que les spécificités du local, notamment la gouvernance locale et la spécialisation économique ont un poids déterminant dans la définition des dynamiques territoriales et par suite des différenciations sociospatiales. Cette hypothèse est déclinée en deux hypothèses opérationnelles: 1. - L’une s’inscrivant dans une perspective historique: Si incontestablement des dynamiques induites de la globalisation affectent les différenciations sociospatiales dans l’espace beyrouthin, nous pensons que l’héritage d’un temps long dans ses dimensions politiques et économiques pèse encore fortement sur ces différenciations dans les banlieues de Beyrouth. 2. L’autre dans une perspective politique: La stabilisation du régime municipal est aujourd’hui la rationalité qui domine l’action municipale. Elle est déterminante de la gouvernance locale dans chaque commune et par suite consubstantielle de l’évolution des différenciations sociospatiales dans ces banlieues. Les banlieues de Beyrouth, considérées comme cas révélateur, sont retenues pour comme terrain d’étude Deux méthodes d’analyse complémentaires sont mobilisées. L’une dite diachronique essaie de repérer les constantes et les variables dans l’histoire d’un district de ces banlieues comprenant les actuelles banlieues sud et sud-est, en insistant sur les rôles particuliers de la gouvernance et de l’économie. L’autre dite synchronique tente de souligner des liens entre des typologies de gouvernance urbaine différentes et leurs impacts en termes de différenciations sociospatiales en mobilisant le concept de régimes urbains. Les principales conclusions sont: - Des arrière-pays consolidés, avant l’étalement des villes centres, ayant leurs propres dynamiques: leur urbanisation, leurs économies et leurs gouvernances locale, leurs trajectoires propres connaissent très tôt la fragmentation urbaine (conclusion en porte-à-faux par rapport au corpus de la fragmentation soulignant le rôle fondateur de la globalisation) - L’architecture du régime urbain local et sa recherche de stabilité interne affectent fortement l’articulation de l’échelle d’action locale aux échelles d’action supérieures. Comme elles affectent certaines formes de dynamiques territoriales locales (notamment celles inscrites dans le registre de construction identitaire des territoires). Toutefois elles semblent avoir moins d’impact sur les aspects centralités et flux des dynamiques territoriales. - La fragmentation politique du territoire peut s’avérer une ressource importante pour les acteurs locaux pour négocier et s’approprier une place, un “lieu” dans les agglomérations urbaines d’aujourd’hui. D’autre part, devant la pression continue que connaissent les territoires urbains des périphéries pour se redéfinir et s’articuler à de nouvelles entités sociospatiales en formation, on peut observer dans certains cas de la véritable innovation en termes de politiques urbaines. Ces municipalités peuvent représenter, comme dans le cas de certaines dans les banlieues de Beyrouth, des laboratoires qui font émerger des nouveaux outils urbains qui pourront servir pour penser et gérer la ville à d’autres échelles. [less ▲]

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See detailDes loups dans la Cité. Eléments d'écologie pragmatiste
Doré, Antoine ULg

Doctoral thesis (2011)

Les politiques contemporaines sont marquées par des bouleversements écologiques qui interrogent la place à accorder à une liste toujours plus longue et hétérogène de prétendants à la vie publique. Cette ... [more ▼]

Les politiques contemporaines sont marquées par des bouleversements écologiques qui interrogent la place à accorder à une liste toujours plus longue et hétérogène de prétendants à la vie publique. Cette thèse propose un examen empirique d’une telle dynamique à partir du cas de la mise en politique des loups en France. En traçant les multiples manières dont les loups interpellent ceux et ce qui les entourent, en décrivant les agencements hybrides d’humains et de non-humains qu’ils forment et transforment sur leur passage et en prêtant attention aux différentes manières dont les acteurs affectés prennent en charge les situations générées par ces animaux, il s’agit d’identifier et de suivre, pas à pas, des portions importantes de quelques-unes des trajectoires qui composent la carrière politique des loups. Cette recherche montre alors comment des scientifiques, des juristes, des publics, des représentants de l’État, des journalistes, etc., mais aussi les loups eux-mêmes, composent ces trajectoires spécifiques marquées par des pratiques, des temporalités, des spatialités, des matérialités particulières. L’analyse révèle comment la présence publique des loups est instaurée par la science, le droit, l’État, etc. Elle rend compte également réciproquement de la manière dont la science, le droit, l’État, etc., s’inventent et se transforment à travers les loups. Cette thèse propose finalement un compte rendu synthétique et réaliste des modalités de construction d’une politique des loups et vise à éclairer deux questions plus générales : dans quel sens peut-on parler des implications politiques de la nature et en quoi cela nous invite-t-il à changer nos habitudes de description et d’aménagement de la vie ensemble ? [less ▲]

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See detailAnalyse comparative de différentes démarches de modélisation hydrologiques pour la représentation de la couverture forestière dans le bassin versant de la Houille (Contribution au projet INTERREG : P2IH)
Deraedt, Deborah ULg

Master's dissertation (2011)

The more simplistic models often overlook the representation of forest cover. Nevertheless it has a significant impact with water uptakes that follows a seasonal variation for example. The comparison of ... [more ▼]

The more simplistic models often overlook the representation of forest cover. Nevertheless it has a significant impact with water uptakes that follows a seasonal variation for example. The comparison of the two global models, PDM and GR4J, highlights the poor quality of simulation on the wooded watershed of the Houille (Belgium). In the case of PDM results are disappointing both in calibration and in validation. The Nash criteria are 0.65 and 0.52 respectively. Calibration of GR4J was a little more promising. But the validation has proved the weakness of the model to simulate the peaks coming from melting snow. The Nash coefficients go down from 0.81 to 0.65. We have tested the EPIC model with the plant parameters recommended for SWAT (which uses the same plant growth module) for spruce and oak. The parameters characterizing the soil are adjusted to the water content values obtained on two measurement sites. One is located in a spruce stand and the other in an oak stand. The comparison of the EPIC model simulation, as describes before, and in situ measurements shows an important difference in terms of water uptake. The model tends to overestimate trees water consumption. It proves the importance of using proper plant parameters to remain representative of the site dynamics and on larger scale, of the watershed dynamics. [less ▲]

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See detailClassification automatique d'images biologiques par variantes d'arbres de décision
Mathéi, Axel ULg

Master's dissertation (2011)

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See detailPrédiction de structures de macromolécules par apprentissage automatique
Marcos Alvarez, Alejandro ULg

Master's dissertation (2011)

Proteins are an essential constituent of cellular life whose biggest part of their function is determined by their tridimensional shape. Nowadays, however, no method is able to predict efficiently ... [more ▼]

Proteins are an essential constituent of cellular life whose biggest part of their function is determined by their tridimensional shape. Nowadays, however, no method is able to predict efficiently tridimensional protein structures based only on their amino acids sequence. We propose here an "ab initio" approach based on the concept of learning for search. Protein structure prediction is modeled in the form of an optimization problem solved by an optimization algorithm that follows an iterative framework in which a structure modification operator is selected and then applied to the current structure. The quality of the new structure is then assessed by an oracle that will determine whether or not the structure is accepted. The repetition of this framework will eventually lead to the sought structure. The critical point of this rationale lies in the choice of the modification operator, which has to be done very accurately in order to avoid the classical pitfalls of optimization problems. The operator selection step will then be subjected to machine learning thus legitimizing the term "learning for search" of the proposed method. The goal of this thesis is to show that machine learning can improve the results obtained via a simple optimization procedure. Our experiments show that this goal is fulfilled. We however know that many choices that we did should be questioned regarding both the optimization and the machine learning procedures. Finally, we can notice that the application domain of this work extends beyond the protein structure prediction problem. There exist indeed many optimization problems in the scientific literature for which no exact neither approximation algorithm exists and that are thus still very badly solved. Such problems could greatly benefit from a "learning for search" approach such as the one described in this work. [less ▲]

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See detailStockage géologique du CO2: l'étanchéité des puits
Dieudonné, Anne-Catherine ULg

Master's dissertation (2011)

Carbon capture and storage is an innovator approach to fight climate changes through the reduction of greenhouse gas emissions. Abandoned coal mines are currently less studied than other reservoirs but ... [more ▼]

Carbon capture and storage is an innovator approach to fight climate changes through the reduction of greenhouse gas emissions. Abandoned coal mines are currently less studied than other reservoirs but could also be used for the storage of carbon dioxide. However the problem of shaft sealing appears to be central as far as the safety, economic, ecologic and health stakes of geological storage are concerned. The purpose of the present work is the study of shaft sealing in the framework of CO2 storage projects. More precisely the problem consists in the numerical study, with the LAGAMINE finite elements code, of gas transfers around a shaft seal system. A coupled hydro-mechanical model of unsaturated geomaterials is presented. The response of the flow model is first studied through a simple synthetic problem simulating the injection of gas in a concrete-made column. It stands out of this first modeling that the advection of the gas phase represents the main transfer mechanism of CO2 in highly unsaturated materials. Furthermore the setting of a bentonite barrier seal allows limiting considerably gas influx to the biosphere. A 2D axisymetric hydromechanical modeling of the Anderlues natural gas storage site is then performed. The design of the shaft seal system appears to be a determinant element to evaluate the risks of CO2 leakage. [less ▲]

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See detailDark atoms : properties and observational consequences
Wallemacq, Quentin ULg

Master's dissertation (2011)

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See detailGéologie appliquée au développement des nouvelles découvertes et aux nouveaux thèmes d’Exploration «Shale Gas Silurien» du Bassin de Berkine (Ghadamès, Algérie)
Djouder, Hocine ULg

Master's dissertation (2011)

Durant de nombreuses années, les compagnies opérant au sein du Bassin de Berkine se sont focalisées sur les Formations gréseuses du Cambro-Ordovicien dans la partie Ouest, du Dévonien inférieur et du ... [more ▼]

Durant de nombreuses années, les compagnies opérant au sein du Bassin de Berkine se sont focalisées sur les Formations gréseuses du Cambro-Ordovicien dans la partie Ouest, du Dévonien inférieur et du Carbonifère dans le centre du bassin, ainsi que dans les séries triasiques sus-jacentes. Le Silurien était considéré comme un objectif secondaire puisque sa qualité de réservoir était négligée au profit de son potentiel de « roche mère ». En effet, la roche mère principale pour les réservoirs paléozoïques est issue des argiles radioactives siluriennes de base « hot shales » rencontrées à plus de 6000 m en profondeur. Le Bassin de Berkine, localisé dans le Sahara Oriental algérien, s‘étend sur près de 102 000 km². Au Paléozoïque inférieur, cette vaste étendue géographique était le siège d‘une sédimentation silicoclastique intracratonique puissant. Les sédiments siluriens se sont alors déposés dans un contexte d‘élévation globale du niveau marin relatif lié à la déglaciation tardi-ordovicienne. Les flux terrigènes prenaient alors leur source au sud du bassin, vers le Môle de Tihemboka et le Hoggar alors en surrection. Deux zones sièges d‘une intense subsidence, le secteur de Menzel Lejmat et le Sillon de Marfag, présentent la série sédimentaire silurienne au complet. Deux entités sont alors mis en évidence, (I) les argiles principales (AP) à graptolites, et (II) les alternances gréso-argileuses (AGA) auxquelles sont rattachées les ensembles réservoirs M, A et B. Ces entités sont composées de 5 séquences principales (Si-1, Si-2, Si-3, Si-4 et Si-5), allant du Llandoverien au Pridolien, mises en évidence dans le système silurien du Bassin de Berkine. Ce découpage est le résultat d‘une analyse séquentielle haute résolution de deux coupes types (Puits MLEP-1 et BRD-5) basée sur l‘enchainement vertical des séquences sur diagraphies et carottes, ainsi que sur les travaux menés dans toute la Synéclise de Ghadamès. Les séquences Si-1 et Si-2 sont datées du Llandoverien. Au cours de cette période, le bassin était le siège d‘une importante sédimentation argileuse de « Hot Shales » et d‘Argiles à Graptolites de 500 à 650 m d‘épaisseur. Ces faciès argileux de plateforme externe profonde passent au sommet à des faciès carbonatés très vite succédés par des sédiments gréseux de l‘unité M1 initiateurs d‘un contexte deltaïque progradant. D‘un point de vue géodynamique, ces deux séquences se rattachent au stade d‘initiation. La séquence Si-3, datée du Wenlockien, atteint 150 m d‘épaisseur. Les sédiments qui la composent se sont déposés dans un contexte marin littoral dominé par un régime tidal transgressif très développé dans cet Ensemble réservoir A. Cet environnement devenant de plus en plus marin vers le sommet de la séquence, avec un dépôt de 50 m d‘argiles litées, s‘achève par une limite de séquence SB4 qui se matérialise au sud du bassin par une surface d‘altération à ciment sidéritique. Le Bassin de Berkine passe alors au stade de maturité avec le dépôt des unités réservoirs A1 et A2. Les séquences Si-4 et Si-5 sont d‘âge Ludovien et Pridolien. Durant cette période, le régime deltaïque a envahi toute l‘aire de sédimentation, passant par un régime progradant du sud-est vers le nord-ouest pour l‘unité B1, à un environnement progressivement fluvio-lacustre pour l‘unité B2. Par la suite, l‘installation définitive des grès massifs du Dévonien en discordance sur le Silurien marque le comblement du bassin et sa sénescence. Cette étude souligne le potentiel réservoir des unités argilo-gréseuses du Silurien terminal du Bassin de Berkine qui est clairement identifié dans des séquences deltaïques progradantes dans lesquelles les processus tidaux peuvent s‘exprimer. Cela suggère aussi des distributions complexes des objets réservoir et de leurs hétérogénités réservoir qui restent à investiguer. [less ▲]

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See detailAlternative strategies for aphid biological control: special regard on honeydew and bacteria from aphids
Leroy, Pascal ULg

Doctoral thesis (2011)

Aphids constitute a scourge in agriculture and are a major problem for crops worldwide. By feeding on the phloem sap but also by injecting saliva and viruses in plant tissues, they cause a weakening and ... [more ▼]

Aphids constitute a scourge in agriculture and are a major problem for crops worldwide. By feeding on the phloem sap but also by injecting saliva and viruses in plant tissues, they cause a weakening and impair the growth of the host-plant. Moreover, honeydew, the aphid excretory product, reduces transpiration and photosynthesis. But honeydew also attracts many predators and parasitoids of aphids, playing a key role in tritrophic interactions between plants, pests and beneficial insects. In this context, the main objective of this thesis was to promote the use of the hoverfly Episyrphus balteatus (De Geer) (Diptera: Syrphidae) as an efficient biological control agent in aphid management strategies. Two different approaches have been developed here with success: (1) the introduction of this auxiliary in the fields or under greenhouses, using a biological control device developed in this work and (2) the attraction, the retention and the oviposition stimulation of the populations naturally present or manually introduced in the fields. To achieve these objectives, special attentions were focused on the aphid honeydew that is abundant on aphid infested plants, with special attention to the bacteria present in this aphid secretion. First, our studies allowed determining that honeydew acts as a volatile and a contact kairomone both for the E. balteatus larvae and adults but also on the Asian coccinellid Harmonia axyridis (Pallas) helping these aphidophagous predators to locate prey. In a second time, using semiochemicals from plants [(Z)-3-hexenol, R-(+)-limonene] and aphids [E-(β)-farnesene] but also crude and artificial honeydew, the hoverfly oviposition was artificially induced (without plants or aphids) on an inert surface. The so obtained eggs were then introduced in field crops to regulate aphid populations (biological control device). Then, the volatile compounds associated with honeydew were identified and tested as potential attractants and ovipositional stimulants: an artificial honeydew as well as an attractive formulation were composed and successfully tested in field crops since they both increased the presence of auxiliaries in targeted areas. Finally, the interaction between the host plant and aphids was envisaged to determine whether aphids are able to modify the host plant amino acid content in order to ingest sufficient nitrogen for growth: this study highlighted that the proportions of glutamine and asparagine significantly increase in the phloem sap when plants are infested. [less ▲]

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See detailSur les ensembles paradoxaux : de Banach-Tarski à Dougherty-Foreman
Kleyntssens, Thomas ULg

Master's dissertation (2011)

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See detailImprimeurs et société dans les Pays-Bas méridionaux et en principauté de Liège (1473-ca 1520)
Adam, Renaud ULg

Doctoral thesis (2011)

La thématique placée au centre de cette dissertation doctorale pourrait se résumer à cette question : comment les premiers imprimeurs se sont intégrés au tissu socio-économique des Pays-Bas méridionaux et ... [more ▼]

La thématique placée au centre de cette dissertation doctorale pourrait se résumer à cette question : comment les premiers imprimeurs se sont intégrés au tissu socio-économique des Pays-Bas méridionaux et de la principauté de Liège aux tournants des XVe et XVIe siècles ? Cette étude a été structurée autour de trois axes. La vétusté des synthèses sur le sujet et l’évolution constante de la recherche ont rapidement imposé la nécessité de réécrire en premier lieu un historique détaillé, ville par ville, de l’introduction de l’art typographique et de son évolution jusqu’en 1520. Les regards se sont ensuite portés sur le métier d’imprimeur avec des questionnements centrés sur le statut juridique et l’organisation de cette profession, sur le fonctionnement interne d’une imprimerie ainsi que sur la commercialisation des livres et le profil de la clientèle. Les résultats de la dernière partie sont le fruit d’une investigation dans la composition de la communauté typographique et d’une tentative de décorticage des trames réticulaires nouées avec les autres acteurs de la société urbaine. [less ▲]

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See detailEvidence for a role of microRNA-21 and microRNA-125b in negatively regulating angiogenic processes
Malvaux, Ludovic ULg

Doctoral thesis (2011)

Recently discovered, miRNAs have quickly become strong regulators of biological processes. These small non-coding RNAs of about 22 nucleotides partially base pair to the 3’UTR of the targeted mRNAs and ... [more ▼]

Recently discovered, miRNAs have quickly become strong regulators of biological processes. These small non-coding RNAs of about 22 nucleotides partially base pair to the 3’UTR of the targeted mRNAs and repress them. Due to their wide range effects, microRNAs were extensively studied in various diseases and were rapidly demonstrated to be deregulated in pathologies such as cancer. More recently, they have been shown to be implicated in vascular network formation (angiogenesis) and were proposed to be used in anti-angiogenic therapies. Nowadays about twenty angiomiRs have been discovered including the endothelial specific miR-126. As observed in several miRNA profiling of endothelial cells and confirmed in our laboratory in HUVECs (human umbilical veins endothelial cells), miR-21 and miR- 125b are highly expressed in this cell type suggesting that these miRNAs could play a role in vascular network formation. We then studied the implication of miR-21 and miR-125b in in vitro as well as in vivo angiogenesis. One of the most studied miRNA in cancer progression is miR-21 as it was shown to modify proliferating properties of numerous tumor cells. Our experiments revealed that miR-21 overexpression and inhibition have no direct effect on endothelial cells proliferation rate. However, miR-21 overexpression leads to the inhibition of HUVECs migration and tube formation as demonstrated in in vitro angiogenic assays. Moreover, opposite effects were observed upon miR-21 inhibition. We also confirmed that RhoB, a small Rho-GTPase implicated in stress fibers formation, is involved in these phenomena as RhoB inhibition using siRNA mimics miR-21 overexpression in endothelial cells. Moreover, miR-21 modulation affects RhoB mRNA and protein expressions. We further demonstrated a direct interaction between miR-21 and the RhoB 3’UTR confirming that miR-21 modulates angiogenesis partially through its effect on RhoB expression. A similar approach was used to study the implication of miR-125b in vascular network formation. In vivo, miR-125b expression was modulated in the zebrafish revealing that miR-125b expression needs to be controlled for proper intersomitic blood vessels establishment. In vitro, miR-125b overexpression decreases HUVECs migration and tube formation whereas miR-125b inhibition increases these functions. A transcriptomic analysis suggests that numerous adhesion molecules such as VE-cadherin or MCAM are involved in these processes. Furthermore, other proteins known to regulate angiogenesis such as the transcription factor ETS1 and the VEGFA receptor, VEGFR2 were also shown to be regulated by miR-125b. This observation confirms that miR-125b modulates angiogenic properties of endothelial cells. Finally, we investigated the impact of miR-21 and miR-125b overexpression in an in vivo pathological model of angiogenesis. In a mouse model of choroïdal neovascularization we demonstrated that miR-21 or miR-125b overexpression in the eyes of these mice decreases blood vessel establishment suggesting that these microRNAs could be used as therapeutic antiangiogenic agents. Taken together, the results presented in this thesis show that miR-21 and miR-125b regulate angiogenesis in vitro and in vivo. [less ▲]

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See detailIntermédiaires et dynamique des réseaux fluides. Du mode d'existence de la norme ISO 14001 en Région wallonne
Semal, Nathalie ULg

Doctoral thesis (2011)

How does a standard "make a living"? How does a written list of requirements acquire some reality? How can a particular agreement take effect in numerous worldwide distant sites?

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See detailRole de l'ADN endogène et d'Interferon Response Factor-3 dans l'induction des réponses immunitaires médiées par les lymphocytes T auxiliaires de type 2.
Marichal, Thomas ULg

Doctoral thesis (2011)

Adaptative type 2 helper T cell (Th2) responses represent an important component of adaptative immunity and are implicated in various (patho)physiological processes such as allergic diseases, host defense ... [more ▼]

Adaptative type 2 helper T cell (Th2) responses represent an important component of adaptative immunity and are implicated in various (patho)physiological processes such as allergic diseases, host defense against helminths and artificially adjuvanted vaccination. Induction of adaptative T responses occurs with the help of innate immune cells, especially dendritic cells (DCs). These DCs make the link between innate and adaptative immunity by taking up antigens in peripheral tissues, migrating to lymphoïd organs and presenting antigens to T lymphocytes. Direct or indirect activation of these cells depends on the interaction between exogenous or endogenous danger signals and conserved innate immune receptors, mainly represented by Pattern Recognition Receptors (PRRs). Despite the importance of Th2 responses, the innate immune mechanisms leading to their activation remain partially unknown. For this reason, we have been interested in immune mechanisms underlying the induction of Th2 responses in two major Th2-dependent immunological processes : airway allergy and vaccination with aluminium hydroxides (alum). Airway allergy, of which the most severe manifestation is allergic ashma, is a constantly increasing disease in developped countries. It appears clearly that the stimulation of PRRs by allergens or immunostimulatory molecules plays a key role in the pathophysiology of airway allergy. In addition, PRRs transduce the signal though a limited number of signaling pathways and the role of Interferon Response Factor (IRF)-3 and IRF-7, two important transcription factors downstream of various PRRs, in the pathogenesis of allergic asthma, remains unknown. Therefore, we have investigated their potentiel implication in this disease. We have discovered that IRF-3, but not IRF-7, plays an essential role in allergic airway sensitization against house dust mite antigens, the main allergen source in humans. We have further demonstrated that IRF-3 was intrinsically required in lung DCs for their proallergic function. The IRF-3-dependent effects were independent of type I interferons, the main target genes of IRF-3. Alum is the most widely used artificial adjuvant in human and animal vaccination. Yet, little is known about its mechanism of action, in particular regarding the nature of signals and signaling pathways promoting Th2 responses. We have postulated that alum, like any other efficient adjuvant, must be expected to stimulate innate immunity. On one hand, alum does not contain any molecular pattern that is recognized by PRRs and, on the other hand, alum is known to be cytotoxic. Therefore, we hypothetised that alum-induced endogenous danger signals could play a role in its adjuvant activity. Here, we report that alum induces cell death and subsequent DNA release. This DNA acts as a endogenous immunostimulatory signal relaying alum adjuvant activity on adaptative responses. Furthermore, we propose that host DNA differentially regulates IgG1 and IgE production following alum immunization. Indeed, an IRF-3-dependent DNA signaling pathway plays a role in the activation of inflammatory DCs, the subsequent induction of Th2 response and IgE isotype switching, whereas DNA also induces IgG1 production through IRF-3- independent mechanisms. The finding that host cell endogenous DNA is a damageassociated molecular pattern relaying alum adjuvant activity may thus help in the comprehension of the mechanisms of action of current vaccines and in the design of novel adjuvants. In conclusion, this work has identified a previously unappreciated role for IRF-3, a transcription factor downstream of various PRRs primarily implicated in antiviral responses, in two Th2-dependent immunological processes: allergic asthma and alum-based vaccination. In these models, we have shown that IRF-3 was intrinsically required in professional antigen presenting cells, namely DCs, in order to activate them, a precondition for the priming of adaptative Th2 responses. In addition, we also discovered that host DNA released upon alum treatment acts as an endogenous danger signal mediating the adjuvant activity of alum. [less ▲]

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See detailSemi-solid constitutive modeling for the numerical simulation of thixoforming processes.
Koeune, Roxane ULg

Doctoral thesis (2011)

Semi-solid thixoforming processes rely on a material microstructure made of globular solid grains more or less connected to each other, thus developing a solid skeleton deforming into a liquid phase ... [more ▼]

Semi-solid thixoforming processes rely on a material microstructure made of globular solid grains more or less connected to each other, thus developing a solid skeleton deforming into a liquid phase. During processing, the material structure changes with the processing history due to the agglomeration of the particles and the breaking of the grains bonds. This particular evolutive microstructure makes semi-solid materials behave as solids at rest and as liquids during shearing, which causes a decrease of the viscosity and of the resistance to deformation while shearing. Thixoforming of aluminum and magnesium alloys is state of the art and a growing number of serial production lines are in operation all over the world. But there are only few applications of semi-solid processing of higher melting point alloys such as steel. This can partly be attributed to the high forming temperature combined with the intense high temperature corrosion that requires new technical solutions. However the semi-solid forming of steels reveals high potential to reduce material as well as energy consumption compared to conventional process technologies, such as casting and forging. Simulation techniques exhibit a great potential to acquire a good understanding of the semi-solid material process. Therefore, this work deals with the development of an appropriate constitutive model for semi-solid thixoforming of steel. The constitutive law should be able to simulate the complex rheology of semi-solid materials, under both steady-state and transient conditions. For example, the peak of viscosity at start of a fast loading should be reproduced. The use of a finite yield stress is appropriate because a vertical billet does not collapse under its own weight unless the liquid fraction is too high. Furthermore, this choice along with a non-rigid solid formalism allows predicting the residual stresses after cooling down to room temperature. Several one-phase material modeling have been proposed and are compared. Thermo-mechanical modeling using a thermo-elasto-viscoplastic constitutive law has been developed. The basic idea is to extend the classical isotropic hardening and viscosity laws to the non solid state by considering two non-dimensional internal parameters. The first internal parameter is the liquid fraction and depends on the temperature only. The second one is a structural parameter that characterizes the degree of structural build up in the microstructure. Those internal parameters can depend on each other. The internal parameters act on the the viscosity law and on the yield surface evolution law. Different formulations of viscosity and hardening laws have been proposed and are compared to each other. In all cases, the semi-solid state is treated as a particular case, and the constitutive modeling remains valid over the whole range of temperature, starting from room temperature to above the liquidus. These models are tested and illustrated by mean of several representative numerical applications. [less ▲]

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