Ce travail a consisté à étudier la N et/ou O acylation enzymatique d’alcool aminés et de dipeptides.Une étude préliminaire consacrée à l’acylation enzymatique d’une molécule modèle, le 6-amino-1-hexanol a démontré la capacité de la lipase B de Candida antarctica immobilisée à catalyser l’acylation de ce substrat dans différents milieux réactionnels. La mise en œuvre de cette réaction en solvants organiques (hexane, 2-méthyl-2-butanol) a conduit à la formation du produit diacylé avec un rendement de 85 % montrant l’absence de chimio-sélectivité de la réaction. L’utilisation de système sans solvant à base d’acide gras libre et de CO2 supercritique a permis d’orienter la chimio-sélectivité de la réaction en faveur de la O-acylation. Les liquides ioniques à cation de type imidazolium et à anions faiblement nucléophiles ont conduit à un taux de conversion de l’alcool aminé de l’ordre de 99 % tout en conservant l’absence de chimio-sélectivité observée en solvant organique. L’étude s’est ensuite focalisée sur l’acylation de dipeptides modèles tels que la Lys-Ser,HCl et la Ser-Leu. L’étude de l’acylation catalysée par la lipase B de Candida antarctica immobilisée de la Lys-Ser,HCl a montré une sélectivité exclusive en faveur de l’acylation de la fonction amine en position e, indépendamment du milieu réactionnel. La O-acylation de la Ser-Leu a permis de mettre en évidence l’influence du groupe carboxylique Cterminal électro-attracteur de Lys-Ser sur la réactivité de la fonction hydroxyle de la sérine. Enfin, la N-acylation enzymatique d’un dipeptide naturel bioactif, la carnosine a été réalisée d’une part en solvant organique, catalysée par la lipase B de Candida antarctica immobilisée et d’autre part, en milieu aqueux biphasique catalysée par l’acyl-transférase de Candida parapsilosis. L’acylation de la carnosine, conduisant à la synthèse de N-oléyl carnosine, n’affecte pas son activité inhibitrice de la xanthine oxydase et semble améliorer son activité anti-radicalaire vis-à-vis de l’anion superoxyde / The present work consisted in studying the N and/or O-enzymatic acylation of amino alcohols and dipeptides. A preliminary study was firstly undertaken about the enzymatic acylation of a bifunctionnal model molecule, 6-amino-1-hexanol and demonstrated the ability of the lipase B of Candida antarctica to catalyze the acylation of this substrate in different reaction media. The reaction performed in organic solvents (hexane, 2-methyl-2-butanol) allowed to the synthesis of the diacylated product with a substrate conversion yield of 85 %, showing the absence of chimio-selectivity of the reaction. The use of a solvent-free system constituted of free fatty acid and the use of supercritical carbon dioxide permitted to orientate the selectivity of the reaction in favour of the O-acylation. Ionic liquids with imidazolium cation and few nucleophilic anions led to a substrate conversion of 99 % and to maintain the absence of chemo-selectivity observed in organic solvents. Then, the study focused on the acylation of model dipeptides like Lys-Ser, HCl and Ser-Leu. Results relative to the acylation of Lys-Ser, HCl catalyzed by the lipase B of Candida antarctica immobilized showed a selectivity in favour of the acylation of the e-amino function independently of the reaction medium. The Ser-Leu O-acylation permitted to demonstrate the influence of the molecular environment (electro-attractor C terminal carboxylic group) on the reactivity of the serine hydroxyl function. Finally, the enzymatic acylation of a bioactive dipeptide was catalyzed by the lipase B of Candida antarctica immobilized in organic solvent and by the acyl-transferase of Candida parapsilosis in lipid-aqueous biphasic medium. The acylation of carnosine allowed the N-oleyl carnosine synthesis. The acylation of carnosine did not affect its xanthine oxydase inhibition activity and seemed to improve its superoxyde anion scavenging property

Diese Dissertation umfasst drei Aufsätzen, die sich mit Erwartungen, Entscheidungen und deren Rückwirkung auf die Umgebung beschäftigen. Der erste Aufsatz untersucht die Binnenwanderung von Ost- nach Westdeutschland. Dabei wird der Zusammenhang von Variation in ökonomischen Disparitäten zwischen der Ursprungs- und der Zielregion und Bildungsniveau, Alter und Arbeitsmarktstatus der wandernden Bevölkerung untersucht. Mit Hilfe der SOEP Daten von 1993 bis 2011 gelangt die Untersuchung zu dem Ergebnis, dass regionale Disparitäten in Verbindung mit der Selbstselektion der Wandernden stehen. Während die Wandernden im Durchschnitt jünger und besser ausgebildet als die Bleibenden sind, verringert sich dieser Unterschied, wenn die Differentiale in den Arbeitslosenquoten zwischen den Regionen steigen. Im zweiten Aufsatz entwickle ich ein Modell zur Untersuchung von prosozialem Verhalten in Begegnungen mit Fremden. Durch das Abstrahieren von Möglichkeiten der Reputationsbildung oder des Bestraftwerdens, entfallen die wesentlichen strategischen Motive für prosoziales Verhalten. Die Entscheidung prosozial zu Handeln ist dann nicht mehr strategisch vorteilhaft sondern intrinsisch motiviert durch Altruismus und einer Neigung sich an das Verhalten anderer anzupassen. In einem zweiten Schritt untersuche ich, ob die Erkenntnisse des Modells mit dem empirisch beobachteten Verhalten übereinstimmen. Der dritte Aufsatz skizziert eine (mögliche) Verhaltensstruktur und notwendige Bedingungen auf Mikroebene, die zu den beobachteten Verhaltensunterschieden in prosozialem Verhalten zwischen dem ländlichen und städtischen Raum führen. Den Rahmen des hier entwickelten Modells bildet das bekannte Gefangenen Dilemma, das wiederholt mit zufällig zugeordneten Partnern einer großen Gesellschaft gespielt wird. Das Modell bezieht Merkmale ein, die sich häufig in realen Begegnungen wiederfinden: imperfekte Information, freiwillige Teilnahme und eine Neigung sich dem Verhalten anderer anzupassen. / This thesis consists of three essays that analyze choices and beliefs to explore how both lead to adaptive behavior. The first essay examines the positive net migration flow from the eastern to western parts of Germany. The migration decision is substantially based on expectations about future developments. With economic conditions changing substantially over the past 20 years in the eastern part of Germany, the incentives to migrate have also altered, so changing the composition of the east-to-west migrant body. This essay explores variations in economic disparities between the region of origin and region of destination, relating them to changes in the skill level, age and labor force status of the migrant population. Analyzing SOEP data from 1993-2011, the findings suggest that, with falling wage differentials, older migrants are less frequent job-to-job movers and are more likely to be non-working prior to migration. Furthermore, while migrants tend to be younger and better educated than stayers, the group of movers becomes partly less distinct from the group of stayers with respect to the skill and age composition when regional disparities in employment opportunities increase. The second and the third essay of this thesis model the decision making process in social interactions between strangers. In these situations, choices are often affected by beliefs about others behavior. In the second essay of this work, I develop a simple model of prosocial behavior for encounters between strangers. By abstracting from the possibility of reputation building and punishment between anonymous partners, I remove the main strategic motives for prosocial behavior so reducing it to a simple non-strategic decision. The principal motivation to behave prosocially is then intrinsic, based on altruism, with a taste for conforming to the behavior of others. In this way, individual decisions are conditional on the behavior of others. Emerging equilibria will then explain the occurrence of prosocial or cooperative behavior within a given society. In a second step, I analyze whether the model’s predictions are consistent with the empirical evidence on the link between beliefs and prosocial behavior using data on blood donations. The third essay outline a (possible) micro-structure and conditions which lead to the observed urban-rural differences in cooperative behavior using agent-based modeling. The model presented here adapts the familiar framework of a prisoners dilemma which is played repeatedly with randomly matched members of a large population. I introduce features that are often found in real world interactions: imperfect information, voluntary participation and a taste for conforming to majority behavior. In this analysis, peoples beliefs about the level of cooperation in the population and their resulting behavior are determined endogenously. Both are governed principally by the experience that they derive from interactions. I present results of an agentbased simulation in order to study the emerging dynamic relationships, to examine how cooperative behavior evolves over time under different circumstances, and to determine how urban-rural differences in behavior emerge. The factors that give rise to rural-urban differences are heterogeneity in individual loss aversion or risk taking, and limited migration possibilities between rural and urban areas.

Les Récepteurs Couplés aux Protéines-G forment la plus importante famille de protéines membranaires chez l’homme et sont impliqués dans de nombreux processus de signalisation cellulaire. Aussi, ils forment un vivier très important de cibles thérapeutiques, déjà identifiées ou potentielles. L’activation d’un RCPG est amorcée par la liaison d’un ligand dans sa partie extra-cellulaire, modifiant ainsi ses propriétés dynamiques intrinsèques. Ces changements structuraux vont alors se répercuter le long des domaines trans-membranaires et promouvoir la dissociation de la Protéine-G hétéro-trimérique, de l’autre côté de la membrane, propageant ainsi le signal au compartiment intra-cellulaire. Ce processus peut être modulé par la liaison de nombreux autres partenaires des RCPGs. Malgré de nombreuses données structurales existantes, ces mécanismes restent encore mal connus à l’échelle moléculaire. Ainsi, la dynamique moléculaire s’est révélée être un outil formidable pour mieux comprendre ces mécanismes. Toutefois, les échelles de taille et de temps requises pour discuter de la dynamique de ces systèmes membranaires limitent ces études aux laboratoires ayant accès à une très grande puissance de calcul. L’objectif des travaux présentés dans ce manuscrit a été de prédire et de mieux comprendre la dynamique d’interaction de différents récepteurs de cette famille avec leurs partenaires, en développant un protocole de dynamique moléculaire, peu coûteux en ressources de calcul, combinant le champ de forces gros-grains MARTINI à un protocole de dynamique moléculaire « Replica-Exchange ».Dans un premier temps, nous présentons la validation de notre protocole pour la prédiction de la liaison de peptides à leur récepteur avec l’étude des peptides Neurotensine, agoniste du Récepteur de la Neurotensine-1, et CVX15, antagoniste du Récepteur Chemokine C-X-C de type-4. Nous montrons également que notre protocole est capable de prédire la sélectivité de plusieurs peptides dérivés de la Neurotensine envers plusieurs récepteurs sauvages et mutés, ne présentant qu’un résidu de différence.Dans un second temps, nous nous sommes intéressés à la dynamique de formation d’un hétéro-dimère de RCPGs impliquant le Récepteur de la Ghréline et le récepteur de la Dopamine D2, couplés aux protéines Gq et Gi respectivement. Ce modèle validé au laboratoire par des mesures LRET montre une interface impliquant une forte complémentarité entre les protéines-G. En se basant sur notre modèle, nous avons conçu et synthétisé des peptides inhibiteurs de la formation de cet hétéro-dimère de protéines-G.Enfin, nous présentons d’autres exemples d’applications de notre protocole et comment il peut être utilisé de concert avec l’expérience avec : la prédiction de la liaison de toxines de serpents aux Récepteurs de la Vasopressine-1a et V2 ; la prédiction de la liaison des peptides Ghréline et Leap2 au Récepteur GHSR-1a et la prédiction de la sélectivité de couplage de différents récepteurs aux peptides C-terminaux de la sous-unité α des protéines-G. / G-Protein Coupled Receptors form the largest family of human membrane proteins and are involved in many cellular signaling processes. Thus, they constitute a pool of already identified or potential pharmacological targets. The activation of a GPCR starts with the binding of a ligand in its extra-cellular part, further modifying its intrinsic dynamical properties. These structural rearrangements are then transmitted along the transmembrane domains and promote the dissociation of the G-protein on the other side of the bilayer, thus propagating the signal into the intra-cellular compartment. This activation process can be modulated by the binding of many other partners of GPCRs. Despite many structural data now available, these mechanisms are still badly known at the molecular scale. In agreement, molecular dynamics simulations appear to be a method of choice to get a better description of these mechanisms. Nevertheless, the size and the time scales required for the simulation of these membrane systems limit such studies to laboratories having access to large computational facilities.The objective of this work was to predict and get a dynamical view of the interactions of several GPCRs with their partners, by developing an affordable molecular dynamics protocol that combines the coarse-grained MARTINI force field to Replica-Exchange MD simulations.In a first step, we validated our protocol by showing its ability to predict the dynamical binding of peptides to their receptors, through the study of Neurotensin, an agonist of the Neurotensin-1 receptor and CVX15, an antagonist of the CXCR4 chemokine receptor. We also show that the same protocol is able to predict the selectivity of several Neurotensin derived peptides against several wild-type/mutated receptors differing by a single residue.In a second step, we were concerned by the dynamical assembly of a GPCR heterodimer involving the Ghrelin and the Dopamine D2 receptors, respectively coupled to Gq and Gi proteins. Our model was validated by LRET measurements confirming a large protein:protein interface and a high complementarity between G-proteins. Based on this model, we designed and synthesized some peptides able to inhibit the assembly of this G-proteins heterodimer.Finally, we describe other applications of our protocol and how it can be employed and confronted to experiments to : predict the dynamical binding of toxins from snake’s venom to the Vasopressin-1a and Vasopressin-2 receptors ; predict the binding of the Ghrelin and Leap2 peptides to their GHSR-1a receptor and predict the coupling selectivity of several receptors to peptides mimicking the C-terminus of the α subunit of G-proteins.

Made available in DSpace on 2016-04-27T16:33:18Z (GMT). No. of bitstreams: 1 ISABEL CRISTINA CHACOROSKI.pdf: 336349 bytes, checksum: 56fa4f25d79068b1d12ea0a6360a0d1e (MD5) Previous issue date: 2007-02-23 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The central problematic of this research refers to the way in which 8th grade teachers in São Paulo state net with more than 10 years of classroom experience manifested themselves about the organization, in their daily activity, to attend what is foreseen to implement the cycle regime and the continued progression. My study searched and analyzed whatever there was any alteration in the educative process for pupils who have completed the fundamental scholarity in legality of the cycle regime, that is, those who got to the 8th grade or the end of cycle II. The semi-structured interviews where made with two state public school teachers in the peripherical zone of Osasco city, and with three state public school teachers in one school of the north zone of São Paulo city. The answers where grouped around some axis indicating the representative central points of possible alterations in the educative process: continued progression or automatic promotion; classroom work routine; school failure and success; evaluation; evaluation instruments; work routine in evaluation day; registers on pupils performances; analyses of pupil performances in collegiate meetings; planning of reinforcement and recuperation activities; following of reinforcement and recuperation pupils; recuperation pupils performances. The study had as its theoretical reference authors like Gimeno Sacristán, Perez Gómez, Antonio Viñao Frago e Pierre Bourdieu. With the obtained results it was possible to identify the inequalities of positions between the subjects who proposed the reforms and those who ought to execute them, distortions on the theme and concerning the cycles, we can affirm that there was not substantive changes in the way they refer to the teaching action. The teachers testimonials make evident that the seriation has not ended, there is fragmentation of teaching developed time, based on the academic year and on short classes, one fractioned and scaled organization, where teaching is understood under the logics of transmition and learning is subject to the existence of pre-requirements which the pupils do not bring on or bring only a few. About the continued progression, we identified that the term is recurrent, although in the description they make about their pedagogic action, the evaluation of the process is objectively connected to the automatic promotion. There were not verified outstanding impacts which take teachers to look for changes favorable to the students, but to alter points around the maintenance of Brazilian school culture selectivity s structural axis / A problemática central desta pesquisa refere-se ao modo pelo qual os professores de 8ª série da rede estadual paulista com mais de 10 anos de experiência na sala de aula se manifestam sobre a organização, em sua atividade cotidiana, para atender o que se prevê para implantação dos ciclos e a progressão continuada. Meu estudo buscou analisar se houve alterações no processo educativo para alunos que completam a escolaridade fundamental na vigência dos ciclos, ou seja, aqueles que chegam à 8ª série ou final do ciclo II. As entrevistas semi-estruturadas foram realizadas com dois professores de escolas públicas estaduais da periferia da cidade de Osasco e com três professores também da rede pública estadual, de uma escola da zona norte da cidade de São Paulo. As respostas foram agrupadas em torno de alguns eixos indicadores dos pontos centrais representativos de eventuais alterações no processo educativo: progressão continuada ou promoção automática; rotina de trabalho em sala de aula; fracasso e sucesso escolar; avaliação; instrumentos de avaliação; rotina de trabalho em dia de avaliação; registros sobre o desempenho dos alunos; análise do desempenho dos alunos nas reuniões colegiadas; planejamento das atividades de reforço e recuperação; acompanhamento dos alunos em reforço e recuperação; desempenho dos alunos em recuperação. O estudo teve como referencial teórico autores como Gimeno Sacristán, Perez Gómez, Antonio Viñao Frago e Pierre Bourdieu. Com os resultados obtidos foi possível identificar as desigualdades de posições entre os sujeitos que propuseram as reformas e os que deveriam executá-la, distorções sobre o tema e no concernente aos ciclos, podemos afirmar que não houve mudanças substantivas no modo de se referir à ação docente. Os depoimentos dos professores evidenciam que a seriação mantém-se, há fragmentação do tempo desenvolvido do ensino, fundamentado no ano letivo e aulas curtas, numa organização fracionada e escalonada, onde o ensino é entendido sob a lógica da transmissão e a aprendizagem fica sujeita à existência de pré-requisitos que os alunos não trazem ou trazem pouco. Sobre progressão continuada identificamos que o termo é recorrente, porém na descrição que realizam sobre sua ação pedagógica, a avaliação do processo está objetivamente ligada à promoção automática. Não se verificam impactos marcantes que levem os professores a procurar mudanças favoráveis aos estudantes, mas sim a alterarem pontos em torno da manutenção do eixo estrutural de seletividade da cultura escolar brasileira

Made available in DSpace on 2016-04-26T20:20:58Z (GMT). No. of bitstreams: 1 Priscilla Okamoto.pdf: 566646 bytes, checksum: 457a8c75c7c44548c851a4446443b007 (MD5) Previous issue date: 2012-05-29 / The purpose of this study is to explore the possibility to apply the principle of the retrocession prohibition to some constitutional rules that deal with limitations on the taxing power. In order to accomplish this, first, the principle of retrocession prohibition was explored. Second, the research studied concepts related to the non cumulativity of ICMS, IPI, PIS/Pasep and Cofins, the ability to pay principle, the selectivity of the ICMS and IPI, the tax exemption, the immunity and the suitable tax treatment for the cooperative act. Based on each limitation, this work evaluated if it is possible to use the principle of retrocession prohibition to prevent the repeal of legislation that gives efficacy to these constitutional restrictions. The results have presented evidences that it is appropriate to apply this principle in some situations / Este trabalho tem como objetivo verificar a possibilidade de aplicação do princípio da vedação do retrocesso a algumas normas constitucionais que tratam de limitações ao poder de tributar. Para tanto, em primeiro lugar, foi estudado o princípio da vedação do retrocesso. Em seguida, foram apresentadas noções sobre a não cumulatividade do ICMS, IPI, PIS/Pasep e Cofins, o princípio da capacidade contributiva, a seletividade do ICMS e do IPI, a isenção, a imunidade e o adequado tratamento tributário ao ato cooperativo. Após o estudo de cada uma dessas limitações, foi averiguado se é possível invocar o princípio da vedação do retrocesso para impedir a revogação de legislação que confere eficácia a essas limitações constitucionais. Chegou-se à conclusão que é cabível a aplicação desse princípio em algumas situações

La valorisation des réservoirs gaziers compacts, dits Tight Gas Reservoirs (TGR), dont les découvertes sont importantes, permettrait d’augmenter significativement les ressources mondiales d’hydrocarbures. Dans l’objectif d’améliorer la production de ces types de réservoirs, nous avons mené une étude ayant pour but de parvenir à une meilleure compréhension de la relation entre l’endommagement et les propriétés de transport des géomatériaux. L’évolution de la microstructure d’éprouvettes qui ont été soumises préalablement à des chargements dynamiques est étudiée. Une estimation de leurs perméabilités avec l’endommagement est tout d’abord présentée à l’aide d’un modèle de pores parallèles couplant un écoulement de Poiseuille avec la diffusion de Knudsen. Nous avons ensuite mené des travaux expérimentaux afin d’estimer l’évolution de la perméabilité avec l’endommagement en relation avec l’évolution de la distribution de tailles de pores. Les mesures de perméabilité sont effectuées sur des cylindres en mortier similaire aux roches tight gas, soumis à une compression uniaxiale. La caractérisation des microstructures des mortiers endommagés est réalisée par porosimétrie par intrusion de mercure. Afin d’estimer l’évolution de la perméabilité, un nouveau modèle hiérarchique aléatoire est présenté. Les comparaisons avec les données expérimentales montrent la capacité de ce modèle à estimer non seulement les perméabilités apparentes et intrinsèques mais aussi leurs évolutions sous l’effet d’un chargement introduisant une évolution de la distribution de taille de pores. Ce modèle, ainsi que le dispositif expérimental employé, ont été étendus afin d’estimer à l’avenir les perméabilités relatives de mélanges gazeux. Le dernier chapitre présente une étude de l’adsorption de méthane dans différents milieux fracturés par chocs électriques. Les résultats, utiles pour l’estimation des ressources en place, ont montré que la fracturation permet de favoriser l’extraction du gaz initialement adsorbé. / The valorization of compact gas reservoirs, called tight gas reservoirs (TGR), whose discoveries are important, would significantly increase the global hydrocarbon resources. With the aim of improving the production of these types of gas, we have conducted a study to achieve a better understanding of the relationship between damage and the transport properties of geomaterials. The microstructure evolution of specimens, which were submitted beforehand to dynamic loading, has been investigated. An estimation of their permeability upon damage is first presented with the help of a bundle model of parallel capillaries coupling Poiseuille flow with Knudsen diffusion. Then, we have carried out an experimental work to estimate the permeability evolution upon damage in relation to the evolution of the pore size distribution in uniaxial compression. The measurements of permeability have been performed on mortar cylinders, designed to mimic typical tight rocks that can be found in tight gas reservoirs. Microstructural characterization of damaged mortars has been performed with the help of mercury intrusion porosimetry (MIP). To estimate the permeability evolution, a new random hierarchical model has been devised. The comparisons with the experimental data show the ability of this model to estimate not only the apparent and intrinsic permeabilities but also their evolutions under loading due to a change in the pore size distribution. This model and the experimental set up have been extended to estimate the relative permeabilities of gas mixtures in the future. The final chapter presents a study of the adsorption of methane on different porous media fractured by electrical shocks. The results, concerning the estimation of the in-place resources, have shown that fracturing can enhance the extraction of the initial amount of adsorbed gas.

L’étude repose sur l’hypothèse que les aides d’État fiscales sont autonomes, se singularisant par rapport aux autres règles du droit fiscal de l’Union. Cela est dû au fait que la véritable nature de l’intégration, la véritable finalité du contrôle des aides fiscales, n’est pas facilement perceptible.Le régime des aides fiscales dépasse son cadre initial de contrôle des systèmes fiscaux pourintégrer celui d’élaboration de règles juridiques communes. Les autorités de l’Union, par le biais du régime des aides fiscales, contrôlent les systèmes fiscaux nationaux ; en même temps, elles parviennent à jouer un rôle important pour la coopération interétatique au regard de la lutte contrela concurrence fiscale dommageable. Plus important encore, elles réussissent à coordonner les systèmes fiscaux nationaux, procédant d’une instrumentalisation du contrôle des aides fiscales,contrôle étant conçu comme un succédané de l’harmonisation fiscale. La démonstration des finalités protéiformes de ce contrôle repose d’abord sur la méthode d’identification d’une aide fiscale, identification qui correspond aux finalités recherchées. La vérification de l’hypothèse initiale de singularisation des aides fiscales pose également la question de sa finalité. Ce contrôle est-il susceptible de façonner la structure même du droit fiscal de l’Union et, d’une manière plus substantielle, la répartition des compétences entre les autorités européennes et nationales ? Une technique comme celle du contrôle des aides fiscales peut-elle potentiellement contribuer à redéfinir la ligne de démarcation entre souveraineté fiscale des États membres et limitation tolérable de celle-ci par le droit de l’Union ? / This thesis is based on the premise that tax state aids differentiate themselves from other tax law related rules of the European Union. This is due to the fact that the true nature of the integration, the true purpose of the regulation of tax state aids, is not so easily discernible. The legal status oftax state aids outreaches its original scope—the scrutiny of fiscal systems—to integrate that of creation of common legal rules. The authorities of the Union, through the tax aids regime, monitor domestic tax systems; at the same time, they come to play an important role in the context of the interstate cooperation tackling harmful tax competition. More importantly, they manage to coordinate domestic tax systems as a result of the “instrumentalization” of the regulation of taxaids. The latter is then regarded as a substitute to tax harmonization. This manifestation of themultifarious objectives of tax state aids regulation is firstly based on the technique ofcharacterization of a tax aid, a characterization corresponding ultimately to the goals as expected.The proof of the initial hypothesis of the self-containment of tax aids raises the question of its purpose. Is this regulation likely to weave the very structure of Union tax law and, more substantially, the division of competences between European and domestic authorities? Is a technique like the one related to tax state aids regulation likely to contribute to redefining the dividing line between member States tax sovereignty and its tolerable limitation by Union law?

Génératrice depuis le VIe siècle de notre ère de crises épidémiques récurrentes en Occident, la peste a profondémentmarqué l’histoire des sociétés européennes, tant sur le plan biologique que culturel, économique et politique. Sil’histoire des épidémies qu’elle a engendrées est aujourd’hui relativement bien connue, un certain nombre de questionssur ses caractéristiques épidémiologiques passées demeurent pour partie irrésolues. En particulier, le caractère sélectifou non de la mortalité par peste à l’égard de l’âge, du sexe et de l’état de santé préexistant des individus faitactuellement débat. À partir d’une approche anthropobiologique, le présent travail se propose de contribuer à cettediscussion. Il livre les résultats de l’étude d’un corpus de 1090 squelettes provenant, d’une part, de quatre sitesd’inhumation de pestiférés de la fin du Moyen Âge et du début de l’époque moderne et, d’autre part, de deuxcimetières paroissiaux médiévaux utilisés hors contexte épidémique. Cette étude révèle en premier lieu l’existenced’une signature démographique commune aux séries en lien avec la peste. Leur composition par âge et par sexe,distincte de celle caractérisant la mortalité naturelle, est au contraire en adéquation avec la structure théorique d’unepopulation vivante préindustrielle. L’examen de divers indicateurs de stress suggèrent par ailleurs que les victimes dela peste jouissaient, à la veille de leur décès, d’un meilleur état de santé que les individus morts en temps normal. Lesrésultats obtenus concourent à démontrer que les facteurs causals de ces lésions squelettiques, d’accoutuméresponsables d’une diminution des chances de survie, n’eurent au contraire qu’une influence mineure, si ce n’est nulle,sur le risque de mourir de l’infection à Yersinia pestis. Ce travail livre in fine un faisceau d’arguments convergents quitendent à prouver que les épidémies de peste anciennes furent à l’origine d’une mortalité non sélective, la maladiefrappant indistinctement les individus des deux sexes, de tous âges et de toutes conditions sanitaires. / From the 6th century onwards, plague caused recurring mortality crises in the Western world. Such epidemics hadprofound biological, cultural, economic and political impacts on European societies. Some aspects of the history ofplague epidemics are currently well known, but many questions remain unanswered, such as the preciseepidemiological pattern of the disease in ancient times. It is unclear whether plague killed people indiscriminately orwhether this disease was selective with respect to age, sex and health. This research contributes to this debate.It consists of an anthropological and paleopathological study of skeletal remains of 1090 individuals, including plaguevictims from four medieval and post-medieval burial grounds, and individuals from two parochial cemeteries in useduring periods of normal mortality. Results from the four plague-related assemblages reveal a peculiar demographicsignature. Age and sex distribution differs clearly from what is expected in non-epidemic periods, when it is shown tocorrespond closely to the demographic structure of the living population. Moreover, the study of various non-specificskeletal stress markers shows that plague victims were in a better health before they passed away than people who diedin non-epidemic periods. The results demonstrate that individuals who suffered stress and disease had a reducedchance of survival in non-epidemic periods, whereas they were not at a higher risk to die during plague epidemics.This study provides evidence that plague was not selective, and that it killed regardless of sex, age, and pre-existing health.

In this work the influence of solid electrolyte additives on the gas sensing properties of tin oxide layers was investigated systematically for the first time. NASICON (NAtrium, Super Ionic CONductor, Na(1+x)Zr2SixP(3-x)O12; 0 <= x <= 3) was used as a model for solid electrolyte additives. The structure of that material is ideally suitable for studies of the correlation between material parameters and the gas sensitivity of the layers. In the NASICON structure the content of mobile Na+-ions can be varied by a factor of four resulting in a simultaneous change of the ionic conductivity sigma(Na+) by approximately three orders of magnitude without considerable structural alterations. Powders of SnO2 and NASICON (x = 0; 2.2; 3) were prepared separately by means of sol-gel routes and mixed in a volume ratio of 80/20. Pastes were prepared from these powders with different compositions and screen printed on alumina substrates with a fourfold structure of thin film gold electrode combs. Four different compositions were characterised simultaneously at elevated temperatures in various gas atmospheres. The conductivity of the layers, when measured in air, decreases considerably with increasing Na+-content in the NASICON additive. This is correlated with enhanced activation energy of the electronic conductivity. The sensitivity of the layers to polar organic molecules like R-OH (alcohols), R-HO (aldehydes) and ROOH (carboxylic acids) is highly enhanced by the NASICON additive. This is observed especially on the admixtures with NASICON of high Na+-content (x = 2.2 and x = 3). On the other hand, the sensitivity to substances with mid-standing functional groups like 2-propanol or propanone can not be enhanced by NASICON additives. Furthermore the sensitivity of these composite layers to CO, H2, NH3, methane, propane, propene and toluene (all exposed as admixtures with air) is lower than the sensitivity of pure SnO2-layers. These observations are well correlated with the results of gas consumption measurements on SnO2/NASICON powders by means of FTIR spectroscopy. In spite of the lack of surface analytical data, a model of surface chemical gas reactions based on a triple phase boundary (SnO2/NASICON/gas atmosphere) was developed, which explains the experimental observations qualitatively. It is assumed that the decrease of the electronic conductivity as observed in the presence of NASICON additives with increasing Na+-content is due to an enhanced electron depletion layer. This is formed in the SnO2 grains by Na+/e- interactions across the SnO2/NASICON-interface. The enormous enhancement of the sensitivity to polar organic molecules may be due to specific nucleophilic interactions with the Na+-ions and coupled Na+/e--interactions at the triple phase reaction sites.

No description available.