256 research outputs found
A linear programming approach to general dataflow process network verification and dimensioning
In this paper, we present linear programming-based sufficient conditions,
some of them polynomial-time, to establish the liveness and memory boundedness
of general dataflow process networks. Furthermore, this approach can be used to
obtain safe upper bounds on the size of the channel buffers of such a network.Comment: In Proceedings ICE 2010, arXiv:1010.530
Etude des phénomènes thermiques associés à la fabrication directe de pièces en TA6V par projection laser
International audienceDirect metal deposition is an additive manufacturing process that enables to build up a component layer-by-layer by the laser melting of a metal powder on a solid substrate, using a coaxial nozzle and a powder delivery head. The heating and cooling that occur in direct laser metal deposition can generate particular thermal conditions which are responsible of the specific microstructure and grain growth and lead to specific build features in term of mechanical properties. In the present work, an experimental study concerning laser-powder interaction, process instrumentation and metallurgical properties of the built parts is exposed. Then, a thermal balance has been established from thermal data of Ti-6Al-4V
Chicken BAFF
Members of the tumor necrosis factor (TNF) family play key roles in the regulation of inflammation, immune responses and tissue homeostasis. Here we describe the identification of the chicken homologue of mammalian B cell activating factor of the TNF family (BAFF/BLyS). By searching a chicken EST database we identified two overlapping cDNA clones that code for the entire open reading frame of chicken BAFF (chBAFF), which contains a predicted transmembrane domain and a putative furin protease cleavage site like its mammalian counterparts. The amino acid identity between soluble chicken and human BAFF is 76%, considerably higher than for most other known cytokines. The chBAFF gene is most strongly expressed in the bursa of Fabricius. Soluble recombinant chBAFF produced by human 293T cells interacted with the mammalian cell-surface receptors TACI, BCMA and BAFF-R. It bound to chicken B cells, but not to other lymphocytes, and it promoted the survival of splenic chicken B cells in culture. Furthermore, bacterially expressed chBAFF induced the selective expansion of B cells in the spleen and cecal tonsils when administered to young chicks. Our results suggest that like its mammalian counterpart, chBAFF plays an important role in survival and/or proliferation of chicken B cells
Faster homomorphic encryption is not enough: improved heuristic for multiplicative depth minimization of Boolean circuits
In somewhat homomorphic encryption schemes (e.g. B/FV, BGV) the size of ciphertexts and the execution performance of homomorphic operations depends heavily on the multiplicative depth. The multiplicative depth is the maximal number of consecutive multiplications for which an homomorphic encryption scheme was parameterized. In this work we propose an improved multiplicative depth minimization heuristic. In particular, a new circuit rewriting operator is introduced, the so called cone rewrite operator. The results we obtain using the new method are relevant in terms of accuracy and performance. Smaller multiplicative depths for a benchmark of Boolean circuits are obtained when compared to a previous work found in the literature. In average, the multiplicative depth is highly improved and the new heuristic execution time is significantly lower. The proposed rewrite operator and heuristic are not limited to Boolean circuits, but can also be used for arithmetic circuits
Chicken BAFF—a highly conserved cytokine that mediates B cell survival
Members of the tumor necrosis factor (TNF) family play key roles in the regulation of inflammation, immune responses and tissue homeostasis. Here we describe the identification of the chicken homologue of mammalian B cell activating factor of the TNF family (BAFF/BLyS). By searching a chicken EST database we identified two overlapping cDNA clones that code for the entire open reading frame of chicken BAFF (chBAFF), which contains a predicted transmembrane domain and a putative furin protease cleavage site like its mammalian counterparts. The amino acid identity between soluble chicken and human BAFF is 76%, considerably higher than for most other known cytokines. The chBAFF gene is most strongly expressed in the bursa of Fabricius. Soluble recombinant chBAFF produced by human 293T cells interacted with the mammalian cell‐surface receptors TACI, BCMA and BAFF‐R. It bound to chicken B cells, but not to other lymphocytes, and it promoted the survival of splenic chicken B cells in culture. Furthermore, bacterially expressed chBAFF induced the selective expansion of B cells in the spleen and cecal tonsils when administered to young chicks. Our results suggest that like its mammalian counterpart, chBAFF plays an important role in survival and/or proliferation of chicken B cell
Morphologie et propriétés rhéologiques de mélanges ternaires PE/PA/argile : influence du mode d'élaboration et de la fraction d'argile.
L'amélioration des propriétés des mélanges de polymères immiscibles par l'ajout d'argile fait l'objet d'un intérêt croissant. Les systèmes ternaires étudiés sont constitués de polyéthylène, de polyamide et d'une nanocharge argileuse présentant une bonne affinité avec le polyamide. Deux modes d'élaboration sont confrontés : mélange d'un nanocomposite PA/argile et du polyéthylène d'une part, et mélange simultanément des trois composants d'autre part. L'influence du taux d'argile sur les propriétés morphologiques et rhéologiques de chaque système est étudiée. La morphologie des systèmes ternaires est très dépendante du mode d'élaboration et de la fraction de la phase dispersée. Les propriétés viscoélastiques sont étudiées en relation avec les propriétés morphologiques. Le comportement viscoélastique a été confronté aux prédictions du modèle de Palierne. Les différences dues au mode d'élaboration sont attribuées à la localisation préférentielle de l'argile dans la phase polyamide et/ou à l'interface PE/PA
Conception robuste de systèmes dynamiques frottants
Le niveau des cycles limites obtenus dans les zones d'instabilité des systèmes frottants dépend fortement de la valeur du coefficient de frottement qui admet des dispersions importantes. Ainsi, l'objectif des travaux est d'étudier le comportement dynamique d'un système frottant afin de pouvoir déterminer la dispersion de l'amplitude des cycles limites lors des instabilités de type sprag-slip en prenant en compte les incertitudes du coefficient de frottement avec une approche par intervalles
Geographic Expansion of Buruli Ulcer Disease, Cameroon
International audienceNo abstract availabl
Maturation of Marginal Zone and Follicular B Cells Requires B Cell Activating Factor of the Tumor Necrosis Factor Family and Is Independent of B Cell Maturation Antigen
B cells undergo a complex series of maturation and selection steps in the bone marrow and spleen during differentiation into mature immune effector cells. The tumor necrosis factor (TNF) family member B cell activating factor of the TNF family (BAFF) (BLyS/TALL-1) plays an important role in B cell homeostasis. BAFF and its close homologue a proliferation-inducing ligand (APRIL) have both been shown to interact with at least two receptors, B cell maturation antigen (BCMA) and transmembrane activator and cyclophilin ligand interactor (TACI), however their relative contribution in transducing BAFF signals in vivo remains unclear. To functionally inactivate both BAFF and APRIL, mice transgenic for a soluble form of TACI were generated. They display a developmental block of B cell maturation in the periphery, leading to a severe depletion of marginal zone and follicular B2 B cells, but not of peritoneal B1 B cells. In contrast, mice transgenic for a soluble form of BCMA, which binds APRIL, have no detectable B cell phenotype. This demonstrates a crucial role for BAFF in B cell maturation and strongly suggests that it signals via a BCMA-independent pathway and in an APRIL-dispensable way
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