245 research outputs found

    Tridendriform algebras on hypergraph polytopes

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    We extend the works of Loday-Ronco and Burgunder-Ronco on the tridendriform decomposition of the shuffle product on the faces of associahedra and permutohedra, to other families of hypergraph polytopes (or nestohedra), including simplices, hypercubes and some new families. We also extend the shuffle product to take more than two arguments, and define accordingly a new algebraic structure, that we call polydendriform, from which the original tridendriform equations can be crisply synthesized.Comment: 30 page

    An introductory study of house spiders (Araneae) in Belgium

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    More than 800 spiders were collected in 43 houses heated in winter, distributed mainly in the northern part of Belgium. Information required for the collections to be eligible for the project was: address, construction year, type of house, and surroundings. The spiders were qualified as ‘house spiders’ or ‘garden spiders’. Of the 93 species collected, 19 could be defined as house spiders. Pholcus phalangioides was the most common, followed by Eratigena atrica and Steatoda triangulosa. Garden spiders enter the house much more often in houses in a rural environment than in those situated in clusters, and mainly in spring. The spiders are most common in autumn when many of them are breeding. The common house spiders colonize houses shortly after their construction

    SPH High-Performance Computing simulations of rigid solids impacting the free-surface of water

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    Numerical simulations of water entries based on a three-dimensional parallelized Smoothed Particle Hydrodynamics (SPH) model developed by Ecole Centrale Nantes are presented. The aim of the paper is to show how such SPH simulations of complex 3D problems involving a free surface can be performed on a super computer like the IBM Blue Gene/L with 8,192 cores of Ecole polytechnique fédérale de Lausanne. The present paper thus presents the different techniques which had to be included into the SPH model to make possible such simulations. Memory handling, in particular, is a quite subtle issue because of constraints due to the use of a variable-h scheme. These improvements made possible the simulation of test cases involving hundreds of million particles computed by using thousands of cores. Speedup and efficiency of these parallel calculations are studied. The model capabilities are illustrated in the paper for two water entry problems, firstly, on a simple test case involving a sphere impacting the free surface at high velocity; and secondly, on a complex 3D geometry involving a ship hull impacting the free surface in forced motion. Sensitivity to spatial resolution is investigated as well in the case of the sphere water entry, and the flow analysis is performed by comparing both experimental and theoretical reference results

    High performance computing 3D SPH model: Sphere impacting the free-surface of water

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    In this work, an analysis based on a three-dimensional parallelized SPH model developed by ECN and applied to free surface impact simulations is presented. The aim of this work is to show that SPH simulations can be performed on huge computer as EPFL IBM Blue Gene/L with 8'192 cores. This paper presents improvements concerning namely the memory consumption, which remains quite subtle because of the variable-H scheme constraints. These improvements have made possible the simulation of test cases involving tens of millions of particles computed by using more than thousand cores. Furthermore, pv-meshless developed by CSCS, is used to show the pressure field and the effect of impact

    085: Heart failure with preserved ejection fraction: changes in clinical parameters between acute presentation and subsequent follow-up

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    PurposeIn the prospective KaRen registry of heart failure with preserved ejection fraction (HFPEF), changes in clinical and biological parameters and medications were assessed between acute presentation and out-patient follow-up in stable state.MethodsThe KaRen study included patients presenting with acute heart failure (HF) according to inclusion criteria: Framingham criteria for HF, left ventricular ejection fraction > or=45% and brain natriuretic peptide (BNP)>100pg/mL or NT-proBNP>300pg/mL. Once stabilized, 4-8 weeks after the index presentation, patients returned as out-patients for repeat assessment. Changes in clinical and biological parameters and medications between inclusion and follow-up were assessed with Students t-test and Chi-square testsResults577 patients were recruited and 458 returned for the 4-8 weeks visit. 56% were women. The median [25-75pctl] age was 79 [72-84] years. Medical history included 78% hypertension, 58% atrial arrhythmia, 26% type II diabetes and 27% serum creatinin >100 micromol/l. The table provides inclusion and follow-up dataConclusionsPatients presenting with HFPEF are elderly and a majority are women, with a high rate of hypertension and atrial arrhythmias. Blood pressure is incompletely controlled. At follow-up, blood pressure and NT-proBNP were reduced, but patients remain symptomatic. Still, efforts are needed to improve symptoms in HFPEF.Table (abstract 85) – Inclusion and follow-up data.Variable Mean (IQR)NYHA I / II / III / IVSBPCreatinineNT-proBNPACEI /ARBB-blockerANTICOAGInclusion0.8 / 9.4 / 40 / 49.8%148 [130-170]93 [74-128]2433 [1272-4790]60%65%41%Follow-up13 / 62.5 / 22.2 / 2.3140 [120-150]95 [75-129]1409 [514-2641]68%67.5%51.3%p<0.00010.003<0.000

    Polymeric nanocapsules prevent oxidation of core-loaded molecules: evidence based on the effects of docosahexaenoic acid and neuroprostane on breast cancer cells proliferation

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    International audienceBackground:Nanocapsules, as a delivery system, are able to target drugs and other biologically sensitive moleculesto specific cells or organs. This system has been intensively investigated as a way to protect bioactives drugs frominactivation upon interaction with the body and to ensure the release to the target. However, the mechanism ofimproved activity of the nanoencapsulated molecules is far from being understood at the cellular and subcellularlevels. Epidemiological studies suggest that dietary polyunsaturated fatty acids (PUFA) can reduce the morbidityand mortality from breast cancer. This influence could be modulated by the oxidative status of the diet and it hasbeen suggested that the anti-proliferative properties of docosahexaenoic acid (DHA) are enhanced by pro-oxidantagents Methods:The effect of encapsulation of PUFA on breast cancer cell proliferation in different oxidative mediumwas evaluated in vitro. We compared the proliferation of the human breast cancer cell line MDA-MB-231 and ofthe non-cancer human mammary epithelial cell line MCF-10A in different experimental conditions. Results:DHA possessed anti-proliferative properties that were prevented by alpha-tocopherol (an antioxidant) andenhanced by the pro-oxidant hydrogen peroxide that confirmsthat DHA has to be oxidized to exert its anti-proliferativeproperties. We also evaluated the anti-proliferative effects of the 4(RS)-4-F4t-neuroprostane, a bioactive, non-enzymaticoxygenated metabolite of DHA known to play a major role inthe prevention of cardiovascular diseases. DHA-loadednanocapsules was less potent than non-encapsulated DHA while co-encapsulation of DHA with H2O2maintainedthe inhibition of proliferation. The nanocapsules slightly improves the anti-proliferative effect in the case of4(RS)-4-F4t-neuroprostane that is more hydrophilic than DHA. Conclusion:Overall, our findings suggest that the sensitivity of tumor cell lines to DHA involves oxidized metabolites.They also indicate that neuroprostane is a metabolite participating in the growth reducing effect of DHA, but it is not thesole. These results also suggest that NC seek to enhance the stability against degradation, enhance cellular availability,and control the release of bioactive fatty acids following their lipophilicities
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