Ces dernières années, la découverte de fraudes scientifiques majeures a créé des ondes de choc dans la communauté scientifique. Le nombre annuel de rétractations a considérablement augmenté, et la plupart sont dues à des cas de fraude. Bien qu’il soit généralement pris pour acquis que tous les coauteurs sont affectés par ces rétractations, l’objectif de cette étude est de vérifier cette présupposition empiriquement. Nous avons recensé toutes les rétractations du domaine biomédical (443) de 1996 à 2006 dans PubMed et mesuré, à l’aide du Web of Science (WOS), la productivité, l’impact et les pratiques de collaboration des coauteurs (1 818) sur une période de cinq ans avant et après la rétractation. Nos résultats montrent que les rétractations ont des conséquences sur la carrière des coauteurs, surtout au niveau du nombre de publications des années subséquentes. Cet impact est plus grand dans les cas de fraude, et pour les premiers auteurs. / Over the last few years, major cases of scientific fraud shocked the scientific community, and the number of retractions each year increased considerably. Scientific misconduct accounts for approximately more than half of those retractions. It is assumed that co-authors of retracted papers are affected by their colleagues’ misconduct, and the aim of this study is to provide empirical evidence of how researchers’ careers are affected by a retraction. We retrieved all (443) publications retracted from 1996 to 2006 from PubMed, signed by 1818 authors. Using the Web of Science (WOS), we measured the productivity, impact and collaboration of each of those authors for a period of five years before and after the retraction. Our results show that retractions affect the career of co-authors, mostly in terms of scientific output. This impact is felt more strongly in cases of fraud and for first authors.

Neste trabalho estudou-se o comportamento reológico e morfológico da mistura polimérica imiscível de polipropileno e poliamida. Como resultado deste estudo obtiveram-se valores de tensão interfacial entre 10mN/m e 13mN/m. A tensão interfacial diminuiu em até 87% quando a mistura é compatibilizada com polipropileno maleado. A análise morfológica no regime de viscoelasticidade linear quando avaliada uma morfologia de emulsão de poliamida em polipropileno revelou diâmetro médio da fase dispersa entre 1,5µm e 20µm. O diâmetro das gotas da fase dispersa diminuiu com a adição de polipropileno maleado chegando a reduções de até 98%, mantendo-se constante a concentração da fase dispersa. No regime de viscoelasticidade não linear foram testados modelos para avaliar o comportamento da mistura em fluxos de cisalhamento e extensão, sendo que somente para os fluxos de extensão foi obtida boa correlação dos resultados experimentais com as previsões teóricas. / Rheological and morphological behaviour of polypropylene and polyamide polymer blend was studied. The values of interfacial tension were obtained between 10mN/m and 13mN/m. The interfacial tension decreased in 87% for compatibilized blend. Morphology analysis for linear viscoelastic regime shows dispersed drop diameter between 1,5µm and 20µm. The diameter of the drops decreased with the addition of maleic polypropylene reducing until 98%, keeping constant the concentration of the disperse phase. In non linear viscoelastic regime different models were tested to evaluate the behavior of the blends in shear and elongacional flows. However, only the elongacional flow results were acquired with theoretical - experimental corroboration.

L’hémostase primaire est un processus permettant la formation d’un clou plaquettaire qui sera stabilisé par un réseau de fibrine. Ce caillot est également consolidé grâce à des phases tardives de l’hémostase primaire résultant des fonctions plaquettaires ; il s’agit principalement de la rétraction qui diminue la taille du caillot afin de le stabiliser. Cette phase est déclenchée par une signalisation « outside-in », consécutive à l’activation de l’intégrine αIIbβ3 et à l’agrégation plaquettaire, et est dépendante d’une réorganisation du cytosquelette. Le premier objectif de ce travail a été d’étudier la signalisation impliquée dans la rétraction, et en particulier l’implication des protéines ROCK, MLCK, Rac-1 et de l’actine dans l’activité de la chaine légère de la myosine (MLC) . MLC est en effet une protéine clé de la réorganisation du cytosquelette. Nous avons mis en évidence une phosphorylation biphasique de MLC dont le deuxième pic, corrélé à la rétraction, est dépendant de Rac1 et de la polymérisation de l’actine. Cette étude a été appliquée à une pathologie, le syndrome de Lowe. Il s’agit d’une maladie génétique rare, également appelée OCRL (Oculo cérébro rénal de Lowe) en référence aux organes majoritairement touchés. Suite à l’observation d’événements hémorragiques per et postopératoires suggérant une instabilité du caillot et l’observation dans une étude précédente d’un temps d’occlusion allongé au PFA100®, nous avons mis en place une étude sur 15 patients et 15 témoins pour lesquels nous avons étudié les différentes phases de l’hémostase primaire. Outre une anomalie et un retard de maturation des mégacaryocytes, nous avons mis en évidence pour la première fois chez ces patients un défaut de la voie « outside-in » responsable d’une anomalie de l’étalement plaquettaire et de la rétraction du caillot. Ce défaut de rétraction, dû à un défaut d’activation de MLC, pourrait être en partie responsable des événements hémorragiques observés chez ces patients. / Primary hemostasis is a mechanism allowing platelet clot formation that is thereafter stabilized by a fibrin network. Fibrin clot is also consolidated following post occupancy events, mainly clot retraction that decrease clot size and thus strengthen it. This phase is triggered by « outside-in » signaling. It is consecutive to αIIbβ3 integrin activation and platelet aggregation, dependent on cytoskeleton organization. Our first objective was to investigate signaling events underlying retraction, and particularly the involvement of ROCK, MLCK, Rac-1, and actin in MLC (Myosin Light Chain) phosphorylation. Indeed, MLC, involved in cytoskeleton rearrangement, is a key protein of this mechanism. We described a MLC biphasic phosphorylation profile, which second peak was dependent of Rac1 and actin polymerization. In a second part, we studied clot retraction signaling in patients with the Lowe syndrome. It is a rare genetic disease, caused by absence of OCRL (oculo cerebro renal of Lowe) protein in reference to the majority of affected organs. The rationale of this study was a previous observation of hemorrhagic events during and after surgeries, suggesting clot instability. A thrombopathy was suggested by a closure time lengthening in the PFA-100 system. The study enrolled 15 patients and 15 controls. Besides a defect of megakaryocyte maturation, we described a defect of « outside-in » signaling responsible for spreading and clot retraction abnormality. This retraction defect, caused by a MLC activity defect, could be partly responsible for hemorrhagic events reported in these patients.

Meiolania platyceps is the stratigraphically youngest, and osteologically best-known members of the enigmatic Paleogene-Holocene testudinatan clade Meiolaniidae. This study generated digital reconstructions of intervertebral mobility using the complete cervical series of M. platyceps as a functional model for inferring feeding habits in giant meiolaniid taxa. A combined photogrammetric and CT data approach was used to compile surface meshes for each individual vertebra, which were then scaled, articulated, and animated to visualise maximal movement through segments radiating from the dorsoventral and mediolateral planes. The results show that M. platyceps was incapable of any kind of neck retraction, which is not surprising given the massive skull and prong-like squamosal horns. In addition, impeded dorsal flexibility via the vertebral processes and projecting anterior margin of the carapace suggests that browsing would have been difficult. Indeed, the neck of M. platyceps was best capable of downward mobility allowing the skull to tilt forward. This presumably brought the muzzle into a grazing position and allowed the animal to feed upon low growing herbaceous vegetation, ferns and palm fruits. Because of the insularity and the skull configuration of this aberrant turtle, an intraspecific combat behaviour has also been suggested in the reconstruction of the lifestyle of M. platyceps. / Meiolania platyceps, en stor behornad sköldpadda som levde under Pleistocen, är en av de yngsta och osteologiskt mest välkända medlemmarna av den enigmatiska Paleogen-Holocena gruppen av testudinata sköldpaddor, dit familjen Meiolaniidae hör. Genom att digitalt rekonstruera exemplarets kompletta nacke, inklusive samtliga halsryggens kotor, kunde artens matvanor såväl som dess potentiella stridsbeteende mellan individer inom arten beskrivas. De individuella kotorna fogades samman genom att kombinera fotogrammetri med CT-data, och efter att ha justerat deras respektive storlekar samt artikulerat dem kunde kotornas maximala rörelsevidd animeras såväl dorsoventralt som mediolateralt. Den mjukvaran som användes för detta var framförallt 3D Studio Max, dock i mindre utsträckning även Agisoft Photoscan Geomagic. Resultatet från de 3D-modeller som genererats i denna undersökning stöder hypotesen att M. platyceps saknade förmågan att dra in dess huvud och hals i skalet, vilket inte är helt överraskande med tanke på dess massiva skalle och utstickande squamosala horn. Skillnaden i hur nacken böjs ventralt jämfört med dorsalt tyder dock på att denna sköldpaddas betningstekniker varit desto mer utvecklade, särskilt eftersom vegetationen under denna tid bestod till största delen av palmer. Skallens position och konfiguration hos detta märkliga djur ger ytterligare information om artens beteende, och det verkar som att intraspecifika slagsmål kan ha förekommit hos M. platyceps. / Meiolania platyceps est l’un des derniers et mieux connus membre de l’énigmatique clade des Meiolaniidae de la période du Paléogène-Holocène. Notre étude fut de générer des reconstructions digitales de la mobilité intervertébrale en utilisant la série complète de cervicales de M. platyceps en tant que modèle fonctionnel afin d’inférer le comportement alimentaires du taxon des meiolanides. Une combinaison de données photogrammétriques et de scannes fut utilisée afin de compiler des surfaces en 3D pour chaque vertèbre, mises à l’échelle, articulées et animées afin de visualiser les mouvements optimaux selon les plans dorsoventral et mediolateral. Les résultats montrent nettement que M. platyceps était incapable de rétracter son cou, ce qui n’est pas surprenant considérant sa tête massive et ses impressionnantes cornes. Qui plus est, la flexibilité dorsale, entravée par les apophyses vertébrales et la marge antérieure de la carapace, suggère que le « browsing » aurait été difficile. En effet, le cou de M. platyceps était mieux à même d’une mobilité ventrale permettant au crâne de basculer vers l'avant. Ce qui aurait entraîné le museau dans une position de « grazing » et aurait permis à l’animal de se nourrir de végétation herbacée, de fougères et de fruits de palmiers. En raison de l'insularité et de la configuration du crâne de cette tortue aberrante, un comportement de combat intraspécifique a également été suggéré dans la reconstruction de la vie de M. platyceps.

This dissertation is about the nature of perspectival thoughts and the context-sensitivity of the language used to express them. It focuses on two kinds of perspectival thoughts: ‘subjective' evaluative thoughts about matters of personal taste, such as 'Beetroot is delicious' or 'Skydiving is fun', and first-personal or de se thoughts about oneself, such as 'I am hungry' or 'I have been fooled.' The dissertation defends of a novel form of relativism about truth - the idea that the truth of some (but not all) perspectival thought and talk is relative to the perspective of an evaluating subject or group. In Part I, I argue that the realm of ‘subjective' evaluative thought and talk whose truth is perspective-relative includes attributions of knowledge of the form 'S knows that p.' Following a brief introduction (chapter 1), chapter 2 presents a new, error-theoretic objection against relativism about knowledge attributions. The case for relativism regarding knowledge attributions rests on the claim that relativism is the only view that explains all of the empirical data from speakers' use of the word "know" without recourse to an error theory. In chapter 2, I show that the relativist can only account for sceptical paradoxes and ordinary epistemic closure puzzles if she attributes a problematic form of semantic blindness to speakers. However, in 3 I show that all major competitor theories - forms of invariantism and contextualism - are subject to equally serious error-theoretic objections. This raises the following fundamental question for empirical theorising about the meaning of natural language expressions: If error attributions are ubiquitous, by which criteria do we evaluate and compare the force of error-theoretic objections and the plausibility of error attributions? I provide a number of criteria and argue that they give us reason to think that relativism's error attributions are more plausible than those of its competitors. In Part II, I develop a novel unified account of the content and communication of perspectival thoughts. Many relativists regarding ‘subjective' thoughts and Lewisians about de se thoughts endorse a view of belief as self-location. In chapter 4, I argue that the self-location view of belief is in conflict with the received picture of linguistic communication, which understands communication as the transmission of information from speaker's head to hearer's head. I argue that understanding mental content and speech act content in terms of sequenced worlds allows a reconciliation of these views. On the view I advocate, content is modelled as a set of sequenced worlds - possible worlds ‘centred' on a group of individuals inhabiting the world at some time. Intuitively, a sequenced world is a way a group of people may be. I develop a Stalnakerian model of communication based on sequenced worlds content, and I provide a suitable semantics for personal pronouns and predicates of personal taste. In chapter 5, I show that one of the advantages of this model is its compatibility with both nonindexical contextualism and truth relativism about taste. I argue in chapters 5 and 6 that the empirical data from eavesdropping, retraction, and disagreement cases supports a relativist completion of the model, and I show in detail how to account for these phenomena on the sequenced worlds view.

Cette thèse porte sur l’analyse de l’activité de traduction philosophique dans le processus de modernisation de Turquie et l’évolution de la conception de la traduction au cours du temps. Dans un premier temps, notre thèse se concentre sur l’histoire de la traduction philosophique. Nous présentons les traductions des textes philosophiques dans la période des Tanzimat et la période après la fondation de la République. Dans un second temps, notre thèse se propose de mener une étude comparative entre les différentes traductions des textes philosophiques. Les questions qui se posent peuvent être énoncées comme suit. Quels types de politique ont-ils pu adopter aussi bien sur un plan théorique que sur le plan du choix des textes à traduire ? Les politiques adoptées ont-elles présentées des modifications notables et significatives tout au long de la période considérée, selon l'évolution de la demande émanant des lecteurs ou selon les exigences des pouvoirs politiques qui se sont succédé ? / This thesis deals with the analysis of the philosophical translation activity in the process of modernization of Turkey and the evolution of the conception of translation over time. First, my thesis focuses on the history of philosophical translation. I present translation activities in general and translations of philosophical texts in the Tanzimat period and the period after the founding of the Republic. In the second section, my thesis proposes to carry out a comparative study between the different translations of philosophical texts. The questions that arise can be stated as follows. What types of policies have they adopted both on the theoretical level and on the choice of the texts to be translated? Have the policies that were adopted resulted in significant changes throughout the period under review, depending on the evolution of the demand from the readers or the requirements of the political authorities that have followed one another?