217 research outputs found

    Saint-Étienne-de-Montluc – Industries lithiques du Paléolithique inférieur et moyen

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    Le site se trouve dans la nappe alluviale de Saint-Étienne-de-Montluc et se présente comme un ensemble superficiel alluvial sablo-argileux contenant silex et grès ladère topographiquement situé entre le Marais et le Sillon de Bretagne. Il recouvre localement un soubassement tertiaire. L’ensemble est enrichi d’altérites du socle et de matériaux de solifluxion. Le caractère torrentiel indiqué par les rognons de silex décimétriques et la présence de nombreux grains rond-mats, ainsi que celle de ..

    Commune de Saint-Étienne-de-Montluc

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    Depuis octobre 2010, trente-trois nouveaux outils du site paléolithique inférieur de la nappe alluviale de Saint-Étienne-de-Montluc, attribuable sans doute au début du Pléistocène moyen, ont été soumis à l’expertise de Jean-Laurent Monnier. Ce corpus comprend neuf pièces provenant des sites déjà prospectés des Fontenelles, Sainte-Marie de l’Aunais/Barreau, l’Entermi et le Bel Ebat. À ceux-ci s’ajoutent deux pièces découvertes au lieu-dit Les Longs Prés, distant d’1 km de l’Entremi, révélant, ..

    Mutations, inflammation and phenotype of myeloproliferative neoplasms

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    Knowledge on the myeloproliferative neoplasms (MPNs) – polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF) – has accumulated since the discovery of the JAK/STAT-activating mutations associated with MPNs: JAK2V617F, observed in PV, ET and PMF; and the MPL and CALR mutations, found in ET and PMF. The intriguing lack of disease specificity of these mutations, and of the chronic inflammation associated with MPNs, triggered a quest for finding what precisely determines that MPN patients develop a PV, ET or PMF phenoptype. The mechanisms of action of MPN-driving mutations, and concomitant mutations (ASXL1, DNMT3A, TET2, others), have been extensively studied, as well as the role played by these mutations in inflammation, and several pathogenic models have been proposed. In parallel, different types of drugs have been tested in MPNs (JAK inhibitors, interferons, hydroxyurea, anagrelide, azacytidine, combinations of those), some acting on both JAK2 and inflammation. Yet MPNs remain incurable diseases. This review aims to present current, detailed knowledge on the pathogenic mechanisms specifically associated with PV, ET or PMF that may pave the way for the development of novel, curative therapies

    Gα16 protein expression is up- and down-regulated following T-cell activation: disruption of this regulation impairs activation-induced cell responses

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    AbstractThe role of heterotrimeric G proteins in T-cell activation is poorly understood. Here we show that in normal, mature human T-cells, expression of Gα16, the 43 kDa α subunit of G16, varies widely, depending on T-cell activation status. Quiescent blood lymphocytes strongly up-regulate Gα16 after Leuco A stimulation: protein expression of Gα16 is maximal at day 4, then decreases. Consistently, in human T-cell clones, expression of Gα16 is high in the first week following activation and decreases rapidly within the second week. In addition, permanent disruption of regulated Gα16 expression in Jurkat T-cells by stable overexpression of 43 kDa Gα16 inhibited Leuco A-induced interleukin-2 production, CD69 up-regulation and cell apoptosis (by 58%, 46% and 74%, respectively), suggesting that coordinate regulation of Gα16 expression is necessary for optimal activation-induced T-cell responses, and that Gα16 proteins may be involved in the negative regulation of TCR signalling

    Développement d'une approche innovante de modélisation de la cinétique de décomposition thermique des matériaux solides en espaces confinés sous-ventilés. Application aux incendies en tunnel

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    Tunnel fires are severe phenomenon whose evolution, usually very fast, can lead to important damages to persons and properties. Tunnel fire safety is based on the use of empirical models, very simplified that describes the evolution of the fire kinetic. Nevertheless, these models does not take into account neither the type of material that are involved in the phenomenon, such as constitutive polymers of road vehicles nor their reactivity in solid phase (thermal decomposition). In order to provide an evolution of the fire description, function of the conditions usually encountered in a tunnel, a predictive model aiming to describe materials’ thermal decomposition has been developed. This mathematical model has been established on the basis of an experimental approach, at small scale, using the Controlled Atmosphere Cone Calorimeter coupled to a Fourier Transform Infrared Spectrometer. The thermal degradation of three different materials (Polyisocyanurate foam, Acrylonitrile Butadiene Styrene and Ethylene Propylene Diene Monomer) has been thoroughly assessed function of key parameters that drives the decomposition process during fire: oxygen concentration and heat flux imposed to the materials. Obtained results for the three materials have then been used to construct multifactorial polynomial regressions, using the methodology known as surface response methodology. The model allows defining the response of the decomposition kinetics (explained variable), function of both the oxygen concentration and the heat flux received at the surface of the material (explanatory variable). Comparisons between numerical and experimental obtained results show the relevance of this approach.Les incendies de tunnels sont des phénomènes violents, à l’évolution rapide qui engendrent la plupart du temps des dommages importants aux personnes et aux biens. La sécurité incendie dans les tunnels routiers est basée sur l’utilisation de modèles empiriques très simplifiés de description de l’évolution de la cinétique de développement de l’incendie. Ces modèles ne prennent cependant pas en compte le type de combustible impliqués dans le phénomène, tels que les polymères constitutifs des enveloppes des véhicules routiers, ni leurs réactivité en phase solide (décomposition thermique). Dans l’optique de faire évoluer la description de l’incendie en fonction des conditions ambiantes caractéristiques d’un tunnel, un modèle prédictif de la décomposition thermique des matériaux a été développé. Ce modèle mathématique a été construit sur la base d’une approche expérimentale à petite échelle faisant intervenir le dispositif du cône calorimètre à atmosphère contrôlée couplé à un spectromètre infrarouge à transformée de Fourrier. Trois matériaux ont fait l’objet d’une étude approfondie de leur décomposition thermique, en fonction de deux paramètres clés influençant la décomposition des solides lors d’un incendie de tunnel : la concentration d’oxygène ambiante et l’éclairement énergétique imposé aux matériaux. Les résultats obtenus pour les trois matériaux choisis (une mousse Polyisocyanurate, un Ethylène Propylène Diène Monomère et un Acrylonitrile Butadiène Styrène) ont été utilisés pour la construction de régressions polynomiales multifactorielles, méthode également connue sous le nom de méthodologie des surfaces de réponses.Le modèle permet de définir la réponse de la cinétique de décomposition (variable expliquée) et son évolution, en fonction de la concentration d’oxygène locale et de l’éclairement énergétique imposé à la surface d’un matériau (variables explicatives). La comparaison des résultats numériques et expérimentaux a alors montré la pertinence de ce type d’approch

    Experimental in vitro transmission of Babesia sp. (EU1) by Ixodes ricinus

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    Babesia sp. (EU1), first characterized in 2003, has been implicated in human cases of babesiosis in Italy, Austria and Germany. It has been identified in roe deer and in its suspected tick vector, Ixodes ricinus, in several European countries. The aim of the present study was to validate the competence of I. ricinus as a vector of Babesia sp. (EU1) via experimental infections. For this purpose, a parasite strain isolated from roe deer was cloned in sheep erythrocytes. After experimental infections, parasite DNA was successfully amplified by PCR in both eggs and larvae originating from infected I. ricinus females and in the salivary glands of females exposed to Babesia sp. (EU1) as nymphs. We also demonstrate that infected females were able to transmit parasite DNA during a new blood meal. Together with previous epidemiological studies, these results validate I. ricinus as a competent vector for Babesia sp. (EU1)

    Unclonable Cryptography in the Plain Model

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    By leveraging the no-cloning principle of quantum mechanics, unclonable cryptography enables us to achieve novel cryptographic protocols that are otherwise impossible classically. Two most notable examples of unclonable cryptography are quantum copy-protection and unclonable encryption. Despite receiving a lot of attention in recent years, two important open questions still remain: copy- protection for point functions in the plain model, which is usually considered as feasibility demonstration, and unclonable encryption with unclonable indistinguishability security in the plain model. In this work, by relying on previous works of Coladangelo, Liu, Liu, and Zhandry (Crypto’21) and Culf and Vidick (Quantum’22), we establish a new monogamy-of-entanglement property for subspace coset states, which allows us to obtain the following new results: • We show that copy-protection of point functions exists in the plain model, with different challenge distributions (including arguably the most natural ones). • We show, for the first time, that unclonable encryption with unclonable indistinguishability security exists in the plain model

    Pathogenesis of Myeloproliferative Neoplasms: Role and Mechanisms of Chronic Inflammation

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    Myeloproliferative neoplasms (MPNs) are a heterogeneous group of clonal diseases characterized by the excessive and chronic production of mature cells from one or several of the myeloid lineages. Recent advances in the biology of MPNs have greatly facilitated their molecular diagnosis since most patients present with mutation(s) in the JAK2, MPL, or CALR genes. Yet the roles played by these mutations in the pathogenesis and main complications of the different subtypes of MPNs are not fully elucidated. Importantly, chronic inflammation has long been associated with MPN disease and some of the symptoms and complications can be linked to inflammation. Moreover, the JAK inhibitor clinical trials showed that the reduction of symptoms linked to inflammation was beneficial to patients even in the absence of significant decrease in the JAK2-V617F mutant load. These observations suggested that part of the inflammation observed in patients with JAK2-mutated MPNs may not be the consequence of JAK2 mutation. The aim of this paper is to review the different aspects of inflammation in MPNs, the molecular mechanisms involved, the role of specific genetic defects, and the evidence that increased production of certain cytokines depends or not on MPN-associated mutations, and to discuss possible nongenetic causes of inflammation

    Semi-Quantum Copy-Protection and More

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    Properties of quantum mechanics have enabled the emergence of quantum cryptographic protocols achieving important goals which are proven to be impossible classically. Unfortunately, this usually comes at the cost of needing quantum power from every party in the protocol, while arguably a more realistic scenario would be a network of classical clients, classically interacting with a quantum server. In this paper, we focus on copy-protection, which is a quantum primitive that allows a program to be evaluated, but not copied, and has shown interest especially due to its links to other unclonable cryptographic primitives. Our main contribution is to show how to dequantize existing quantum copy-protection from hidden coset states, by giving a construction for classically-instructed remote state preparation for coset states. We then apply this dequantizer to obtain semi-quantum cryptographic protocols for copy-protection and tokenized signatures with strong unforgeability. In the process, we present the first secure copy-protection scheme for point functions in the plain model and a new direct product hardness property of coset states which immediately implies a strongly unforgeable tokenized signature scheme
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