Depuis la fin des années 1990, face aux risques sanitaires multiples associés à l’alimentation, les écoles sont devenues un champ d’intervention privilégié pour sensibiliser les enfants à la « bonne » alimentation. En France, diverses instances publiques se sont associées pour concevoir et diffuser de vastes campagnes info-communicationnelles à l’échelle nationale dont l’un des objectifs consiste à éduquer les enfants à un ensemble de normes et valeurs liées à ce qui est aujourd’hui désigné comme sain. Cette thèse se propose de saisir les enjeux de cette communication publique ainsi que sa circulation d’instance en instance et d’acteur en acteur jusque dans les écoles. Elle s’appuie sur une analyse sémio-pragmatique des dispositifs info-communicationnels et infopédagogiques produits de 2010 à 2015 par les instances publiques, ainsi que sur des observations participantes et des entretiens semi-directifs dans les écoles. Cette enquête fait apparaître deux logiques à l’œuvre. D’une part, traduits en prescriptions, protocoles et missions selon les différentes échelles territoriales et institutionnelles, les messages de santé publique montrent la volonté d’inculquer aux enfants des modèles normatifs afin qu’ils apprennent à diriger par eux-mêmes leurs conduites et celles des autres. D’autre part, ces prescriptions et dispositifs sont adaptés, transformés, réappropriés et détournés de leur objectif premier à chaque étape de leur circulation. À l’origine de ces transformations, les acteurs successifs forment une chaîne dont les derniers maillons sont les enfants. / Since the end of 1990s and facing up to numerous sanitary risks associated to food, schools became the favorite field of intervention to make children sensitive to so-called “proper”food. In France, diverse public authorities joined to develop and diffuse vast information and communication campaigns on a national scale. One purpose of these campaigns is educatingchildren in a set of standards, norms and values bound to what is seen today as healthy. This work is dedicated to understand what is at stake in this public communication as well as its progress through various authorities and various actors up to schools. It is built upon a semio pragmatic analysis of informative and pedagogical scheme produced between 2010 and 2015 by public authorities as well as observations and semi-directive interviews in schools. This work reveals two logics. On one hand, as messages about public health are translated into prescriptions, protocols and missions according to the various territorial and institutional scales, they demonstrate the will to instill normative models into children so that they learn to manage by themselves their conducts and those others. On the other hand, those prescriptions and devices are adapted, transformed and diverted from their first objective in every stage of their progress. At the origin of these transformations, the successive actors form a chain the last links of which are the children.

Quel rôle est tenu par la fiction dans la relation qui s’établit entre des enfants - âgés entre 6 et 12 ans - et des monuments ? Financée par la région PACA, cette recherche s’intéresse aux formes prises par le monument dans sa « circulation triviale » (Jeanneret, 2008) et aux appropriations qu’en font les enfants. Partant du constat que la fiction nourrit les médiations proposées aux jeunes dans les monuments mais aussi que l’exposition médiatique de ces derniers est importante dans les fictions enfantines - notamment à travers le motif du château , trois niveaux de recherche ont été pensés. Le premier consiste à identifier, via une analyse sémiotique, les opérateurs de la fiction dans les médiations éducatives des monuments désignées explicitement comme telles - audioguides, livrets de visite, ateliers. La fiction mobilisée dans un tel contexte occupe des fonctions qui s’entrecroisent : didactique, ludique et expressive. Dans une démarche similaire, le second niveau propose d’analyser les processus de fabrication de monuments stéréotypés circulant massivement dans les fictions des industries culturelles - en prenant pour exemple, deux monographies : celle du château rêvé de Disney et de l’école Poudlard dans la saga Harry Potter. Le monument y agit principalement de façon cathartique, axiologique et diégétique. De fait, ces deux premiers niveaux mettent en exergue l’opérativité socio-culturelle de la fiction dans la relation proposée au monument. Mais que produisent ces opérateurs fictionnels ? Comment circulent-ils, se réinscrivent-ils et quelles valeurs confèrent-t-ils à la monumentalité ? Pour répondre à ces questions, le dernier niveau s’intéresse à leur réinscription dans les discours d’enfants sous une forme singulière de production de sens - appelés microliens. Ces derniers sont entendus comme des connexions infimes créées par analogie par des sujets entre des opérateurs de dispositifs actualisés dans des expériences sociales - la visite par exemple - et participant à l’élaboration d’un « être culturel » - la monumentalité. Les résultats montrent que la fiction permet des appropriations singulières du temps et de l’espace du monument et différentes formes d’immersion fictionnelle prises et de réflexivité de l’expérience vécue chez les enfants. Pour ces raisons, les expériences liées au monument seraient « polychrésiques » c’est-à-dire objets de constantes réappropriations et « prises(e) sans cesse dans un large spectre de logiques sociales différentes » (Jeanneret, op.cit. : 83). Le décloisonnement des domaines de la vie sociale que propose l’étude de la « trivialité », en tant que circulation des savoirs, montre que la naissance ou le développement d’une pratique pourrait se concevoir dans et avec un « ailleurs » imprégné de discours circulant comprenant des moments, des objets, des discours en dehors des monuments, autrement dit dans un espace ventilé.. / Which role is played by fiction in the relationship established between children - aged from 6 to 12 years old - and historical monuments? Funded by the PACA region, this research focuses on the forms taken by the historical monument in its « trivial circulation » (Jeanneret, 2008) and the appropriations that children do. Noting that fiction feeds mediations offered to young people in the monuments but also that the media exposure of these is important in children’s fictions - particularly through the pattern of the castle – three levels of search are thought. The first is to identify, through a semiotic analysis, operators of fiction in educational mediations of monuments explicitly designated as such – audio guides, visit booklets, workshops. Mobilized fiction in this context holds positions that intersect themselves: didactic, playful and expressive. In a similar move, the second level offers to analyse the manufacturing processes of stereotyped monuments massively flowing in the fictions of cultural industries - taking for example, two monographs: the dreamed castle of Disney and the Hogwarts School of Witchcraft and Wizardry in Harry Potter saga. The monument mainly acts in a cathartic, axiological and diegetic way. In fact, these two first levels highlight the socio-cultural operability of fiction in the proposed relation to the monument. But what do these fictional operators produce? How do they run, re-enroll themselves and what values do they give to “monumentality”? To answer these questions, the last level is interested in their re-enrollment in children’s speeches in a singular form of sense of production - called microlinks. These are understood as tiny connections created by analogy by subjects between updated devices operators in social experiences - the visit for example - and participating in the development of a « cultural being » - monumentality. The results show that fiction allows singular appropriations of time and space of the monument and different forms of fictional immersion taken and of reflexivity of the experience lived by children. For these reasons, the experiences linked to the monument would be « polychrésiques » which means objects of constant reappropriations and « taken constantly in a wide spectrum of different social logics » (Jeanneret, op.cit.: 83). The compartmentalisation of areas of social life that includes the study of the « triviality » as knowledge circulation, shows that the birth or the development of a practice can be conceived in and with an « elsewhere » imbued with running speech including moments, objects, speeches outside monuments, in other words in a ventilated space.

Neste projeto apresentamos algumas direções de pesquisa desenvolvidas no estudo da geometria/topologia da singularidade, no ambiente real e complexo, para funções e aplicações polinomiais. Para isso, utilizaremos as ferramentas da teoria de estratificação, técnicas de decomposição Open book, condições de regularidade no sentido Malgrange, t-regularidade, \'rho\'E-regularidade e trivialidade topológica no infinito / On this project we present some research lines developed in the study of the geometry/ topology of singularity, on the real and complex settings, for functions and polynomial mappings. For this, we use tools from stratification theory, techniques of Open Book decomposition, Malgrange regularity condition, t-regularity condition, \'rho\'E-regularity and topological triviality at infinity

Aquesta tesi té tres objectius. En primer lloc, estudiem generalitzacions de la jerarquia no ample relatives a una família de tipus parcials. Aquestes jerarquies en permeten classificar la complexitat del “forking” respecte a una família de tipus parcials. Si considerem la família de tipus algebraics, aquestes generalitzacions corresponen a la jerarquia ordinària, on el primer i el segon nivell corresponen a one-basedness i a CM-trivialitat, respectivament. Fixada la família de tipus regulars “no one-based”, el primer nivell d'una d'aquestes possibles jerarquies no ample ens diu que el tipus de la base canònica sobre una realització és analitzable en la família. Demostrem que tota teoria simple amb suficients tipus regulars pertany al primer nivell de la jerarquia dèbil relativa a la família de tipus regulars no one-based. Aquest resultat generalitza una versió dèbil de la “Canonical Base Property” estudiada per Chatzidakis i Pillay. En segon lloc, discutim problemes d'eliminació de hiperimaginaris assumint que la teoria és CM-trivial, en tal cas la independència del “forking” té un bon comportament. Més concretament, demostrem que tota teoria simple CM-trivial elimina els hiperimaginaris si elimina els hiperimaginaris finitaris. En particular, tota teoria petita simple CM-trivial elimina els hiperimaginaris. Cal remarcar que totes les teories omega-categòriques simples que es coneixen són CM-trivials; en particular, aquelles teories obtingudes mitjançant una construcció de Hrushovski. Finalment, tractem problemes de classificació en les teories simples. Estudiem la classe de les teories simples baixes; classe que inclou les teories estables i les teories supersimples de D-rang finit. Demostrem que les teories simples amb pes finit acotat també pertanyen a aquesta classe. A més, provem que tota teoria omega-categòrica simple CM-trivial és baixa. Aquest darrer fet resol parcialment una pregunta formulada per Casanovas i Wagner. / The development of first-order stable theories required two crucial abstract notions: forking independence, and the related notion of canonical base. Forking independence generalizes the linear independence in vector spaces and the algebraic independence in algebraically closed fields. On the other hand, the concept of canonical base generalizes the field of definition of an algebraic variety. The general theory of independence adapted to simple theories, a class of first-order theories which includes all stable theories and other interesting examples such as algebraically closed fields with an automorphism and the random graph. Nevertheless, in order to obtain canonical bases for simple theories, the model-theoretic development of hyperimaginaries --equivalence classes of arbitrary tuple modulo a type-definable (without parameters) equivalence relation-- was required. In the present thesis we deal with topics around the geometry of forking in simple theories. Our first goal is to study generalizations of the non ample hierarchy which will code the complexity of forking with respect to a family of partial types. We introduce two hierarchies: the non (weak) ample hierarchy with respect to a fixed family of partial types. If we work with respect to the family of bounded types, these generalizations correspond to the ordinary non ample hierarchy. Recall that in the ordinary non ample hierarchy the first and the second level correspond to one-basedness and CM-triviality, respectively. The first level of the non weak ample hierarchy with respect to some fixed family of partial types states that the type of the canonical base over a realization is analysable in the family. Considering the family of regular non one-based types, the first level of the non weak ample hierarchy corresponds to the weak version of the Canonical Base Property studied by Chatzidakis and Pillay. We generalize Chatzidakis' result showing that in any simple theory with enough regular types, the canonical base of a type over a realization is analysable in the family of regular non one-based types. We hope that this result can be useful for the applications; for instance, the Canonical Base Property plays an essential role in the proof of Mordell-Lang for function fields in characteristic zero and Manin-Mumford due to Hrushovski. Our second aim is to use combinatorial properties of forking independence to solve elimination of hyperimaginaries problems. For this we assume the theory to be simple and CM-trivial. This implies that the forking independence is well-behaved. Our goal is to prove that any simple CM-trivial theory which eliminates finitary hyperimaginaries --hyperimaginaries which are definable over a finite tuple-- eliminates all hyperimaginaries. Using a result due to Kim, small simple CM-trivial theories eliminate hyperimaginaries. It is worth mentioning that all currently known omega-categorical simple theories are CM-trivial, even those obtained by an ab initio Hrushovski construction. To conclude, we study a classification problem inside simple theories. We study the class of simple low theories, which includes all stable theories and supersimple theories of finite D-rank. In addition, we prove that it also includes the class of simple theories of bounded finite weight. Moreover, we partially solve a question posed by Casanovas and Wagner: Are all omega-categorical simple theories low? We solve affirmatively this question under the assumption of CM-triviality. In fact, our proof exemplifies that the geometry of forking independence in a possible counterexample cannot come from finite sets.

En mathématiques et en logique classiques, on démontre que {P,¬P}├Q. C’est le fameux ex contradictione sequitur quodlibet, nommé également principe d’explosion. Si une théorie contradictoire est condamnée à exploser, c.à.d. à devenir triviale et à perdre tout intérêt pour la science, il faut à tout prix éviter la contradiction qui, pour ainsi dire, joue le rôle de détonateur. Dès lors, il devient impératif de nier toute conjonction d’une formule et de sa négation. C’est le principe de non-contradiction (PNC) symbolisé par ¬(P^¬P), une tautologie en logique mathématique classique. Aristote, déjà, dans l’antiquité, avait explicitement formulé le PNC qui, depuis, a été élevé au rang de principe définitif et absolu. Quelques rares mais irréductibles détracteurs, toutefois, ont mis en cause le statut absolu de ce principe. La présente thèse est une rediscussion du PNC -de son statut, de sa validité, de sa valeur- qui s’appuie sur le travail du logicien J. Łukasiewicz. Il sera établi que la mise en cause de l’absoluité du PNC proposée par le logicien n’est pas un prolongement des thèses sophistes antiques. Ses critiques s’inscrivent dans le cadre d’une Gegenstandstheorie twardowsko-meinongienne. La combinaison des éléments hérités de la théorie des objets et d’une analyse originale usant des outils de l’algèbre de la logique dans l’interprétation des textes anciens a permis au logicien de dégager l’idée cardinale selon laquelle on peut récuser l’absoluité du PNC sans tomber dans le trivialisme. Il sera démontré que ses travaux contiennent, pour la logique, l’esquisse d’un nouveau paradigme fondé sur la désabsolutisation du PNC, par sa dissociation d’avec le principe d’explosion. / In mathematics and classical logic, one proves that {P,¬P}├Q. This is the celebrated ex contradictione sequitur quodlibet, also named the principle of explosion. If a contradictory theory is condemned to explode, that is to become trivial and to lose all interest from a scientific point of view, one must at all costs avoid any contradiction which plays the role of detonator. Consequently, it is necessary to deny any conjunction of a formula and its negation. This is the principle of non-contradiction (PNC) symbolised by ¬(P^¬P), a tautology in classical mathematical logic. Already in antiquity, Aristotle had explicitly formulated PNC which, since, has been elevated to the status of a definitive and an absolute principle. However, a few obstinate critics have questioned the absolute status of this principle. The present thesis is a reappraisal of PNC -of its status, its validity, its value- which builds on the work of the logician J. Łukasiewicz. It will be demonstrated that the critique of absoluteness attributed to PNC proposed by Łukasiewicz is not a continuation of the theses of the ancient sophists. His criticisms can be placed in the framework of a Twardowskian-Meinongian Gegenstandstheorie. The combination of elements from a theory of objects and an original analysis using the tools of the algebra of logic in the interpretation of ancient texts has enabled Łukasiewicz to discern an essential idea according to which one can challenge the absoluteness attributed to PNC without sinking into triviality. It will be shown that his works contain, for logic, an outline for a new paradigm based on the disabsolutization of PNC, by dissociating it from the principle of explosion.

Neste projeto apresentamos algumas direções de pesquisa desenvolvidas no estudo da geometria/topologia da singularidade, no ambiente real e complexo, para funções e aplicações polinomiais. Para isso, utilizaremos as ferramentas da teoria de estratificação, técnicas de decomposição Open book, condições de regularidade no sentido Malgrange, t-regularidade, \'rho\'E-regularidade e trivialidade topológica no infinito / On this project we present some research lines developed in the study of the geometry/ topology of singularity, on the real and complex settings, for functions and polynomial mappings. For this, we use tools from stratification theory, techniques of Open Book decomposition, Malgrange regularity condition, t-regularity condition, \'rho\'E-regularity and topological triviality at infinity