49 research outputs found

    Numerical modelling of hydrodynamics and tidal energy extraction in the Alderney Race: a review

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    (IF 4.23; Q1)International audienceThe tides are a predictable, renewable, source of energy that if harnessed, can provide significant levels of electricity generation. Alderney Race, with current speeds that exceed 5 m/s during spring tides, is one of the most concentrated regions of tidal energy in the world, with the upper bound resource estimated at 5.1 GW. Due to its significance, the Alderney Race is frequently used for model case studies of tidal energy conversion, and here we review these model applications and outcomes. We examine a range of temporal and spatial modelling scales, from regional models applied to resource assessment and characterisation, to more detailed models that include energy extraction and array optimization. We also examine a range of physical processes that influence the tidal energy resource, including the role of waves and turbulence in tidal energy resource assessment and loadings on turbines. The review discusses model validation, and covers a range of numerical modelling approaches, from 2D to 3D tidal models, two-way coupled wave-tide models, Large Eddy Simulation (LES) models, and the application of optimization techniques. The review contains guidance on model approaches and sources of data that can be used for future studies of the Alderney Race, or translated to other tidal energy regions

    Obesity promotes fumonisin B1 hepatotoxicity

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    Obesity, which is a worldwide public health issue, is associated with chronic inflammation that contribute to long-term complications, including insulin resistance, type 2 diabetes and non-alcoholic fatty liver disease. We hypothesized that obesity may also influence the sensitivity to food contaminants, such as fumonisin B1 (FB1), a mycotoxin produced mainly by the Fusarium verticillioides. FB1, a common contaminant of corn, is the most abundant and best characterized member of the fumonisins family. We investigated whether diet-induced obesity could modulate the sensitivity to oral FB1 exposure, with emphasis on gut health and hepatotoxicity. Thus, metabolic effects of FB1 were assessed in obese and non-obese male C57BL/6J mice. Mice received a high-fat diet (HFD) or normal chow diet (CHOW) for 15 weeks. Then, during the last three weeks, mice were exposed to these diets in combination or not with FB1 (10 mg/kg body weight/day) through drinking water. As expected, HFD feeding induced significant body weight gain, increased fasting glycemia, and hepatic steatosis. Combined exposure to HFD and FB1 resulted in body weight loss and a decrease in fasting blood glucose level. This co-exposition also induces gut dysbiosis, an increase in plasma FB1 level, a decrease in liver weight and hepatic steatosis. Moreover, plasma transaminase levels were significantly increased and associated with liver inflammation in HFD/FB1-treated mice. Liver gene expression analysis revealed that the combined exposure to HFD and FB1 was associated with reduced expression of genes involved in lipogenesis and increased expression of immune response and cell cycle-associated genes. These results suggest that, in the context of obesity, FB1 exposure promotes gut dysbiosis and severe liver inflammation. To our knowledge, this study provides the first example of obesity-induced hepatitis in response to a food contaminant.L.D. PhD was supported by the INRAE Animal Health department. This work was also supported by grants from the French National Research Agency (ANR) Fumolip (ANR-16-CE21-0003) and the Hepatomics FEDER program of Région Occitanie. We thank Prof Wentzel C. Gelderblom for generously providing the FB1 and for his interest and support in our project. B.C. laboratory is supported by a Starting Grant from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. ERC-2018-StG- 804135), a Chaire d'Excellence from IdEx Université de Paris - ANR-18-IDEX-0001, an Innovator Award from the Kenneth Rainin Foundation, an ANR grant EMULBIONT ANR-21-CE15-0042-01 and the national program “Microbiote” from INSERM. We thank Anexplo (Genotoul, Toulouse) for their excellent work on plasma biochemistry. Neutral Lipids MS and NMR experiments were performed with instruments in the Metatoul-AXIOM platform. Sphingolipid MS analysis were performed with instruments in the RUBAM platform. The FB1 plasma levels were determined using an UPLC-MS/MS instrument part of the Ghent University MSsmall expertise centre for advanced mass spectrometry analysis of small organic molecules. We thank Elodie Rousseau-Bacquié and all members of the EZOP staff for their assistance in the animal facility. We are very grateful to Talal al Saati for histology analyses and review, and we thank all members of the US006/CREFRE staff at the histology facility and the Genom'IC platforms (INSERM U1016, Paris, France) for their expertise.Peer reviewe

    Paraplégie traumatique de l'enfant (mise au point sur la prise en charge et le devenir urologique à long terme)

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    POITIERS-BU Médecine pharmacie (861942103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Synthèse architecturale basée sur le modèle polyédrique (validation et extensions de la méthodologie MMAlpha)

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    La conception de circuits intégrés spécialisées requiert fréquemment des architectures à hautes performances, notamment pour effectuer des algorithmes de traitement du signal. Le logiciel MMAlpha, basé sur le formalisme des équations récurrentes et le modèle polyédrique, est un logiciel permettant la détection et l'exploitation du parallélisme présent dans un nid de boucles afin de réaliser un circuit intégré parallèle. L'objectif des recherches présentées dans ce mémoire est de valider l'utilisation de MMAlpha et du modèle sous-jacent pour la synthèse d'architectures et d'identifier des extensions éventuelles lui permettant de mieux s'intégrer dans le flot de conception.Dans un premier temps, un filtre adaptatif retardé a été conçu et réalisé avec ce logiciel. Certaines extensions ont été réalisées et incorporées au logiciel.Enfin, une extension permettant la synthèse de programmes Alpha ordonnancées avec un temps multidimensionnel a fait l'objet de recherches plus approfondies.RENNES1-BU Sciences Philo (352382102) / SudocVILLEURBANNE-DOC'INSA LYON (692662301) / SudocSudocFranceF

    Hyperprolactinémie secondaire à un microadénome, à un macroadénome enclos ou idiopathique traitée par agonistes dopaminergique (devenir des patients après la première fenêtre thérapeutique)

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    Objectifs : Etudier le taux de rémission de l'hyperprolactinémie après un traitement prolongé par agonistes dopaminergiques chez des patients suivis pour un microprolactinome, un macroprolactinome enclos ou une hyperprolactinémie primaire idiopathique et sélectionnés selon les critères des recommandations. Identifier des facteurs prédictifs de rémission prolongée et étudier le devenir des patients qui récidivent. Matériel et méthodes : Notre étude porte sur 81 patients pris en charge entre 1992 et 2009. Parmi ces patients, 56 ont eu une première fenêtre thérapeutique après un traitement par agonistes dopaminergiques pendant au moins deux ans. Résultats : Notre cohorte de patients est composée majoritairement de femmes (52/4), d'un âge moyen au diagnostic de 31 10 ans, traités depuis une durée médiane de 45,25 mois. Après une première fenêtre thérapeutique, 31,5% des patients sont en rémission avec un recul d'au moins un an. 37 patients ont récidivé. La récidive survient dans les trois premiers mois, dans 75% des cas. Parmi les patients qui ont récidivé, 19 ont eu au moins une 2ème fenêtre thérapeutique permettant l'évolution vers une rémission prolongée chez 6 patients. La récidive de l'hyperprolactinémie après plusieurs fenêtres thérapeutiques survient dans les mêmes délais. Le seul facteur prédictif de bonne réponse à l'arrêt du traitement est l'évolution vers la ménopause au cours de la période de traitement. Conclusion : Nos résultats en terme de rémission de 31,5% sont comparables aux données de la littérature. La récidive survient dans les trois premiers mois dans 75% des cas. L'évolution vers la ménopause au cours de la période de traitement augmente les chances de rémission.LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF

    Hardware synthesis for systems of recurrence equations with multidimensional schedule

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    International audienceThis paper introduces methods for extending the classical systolic synthesis methodology to multi-dimensional time which implies the use of memories in the resulting architecture. Memory functions are used to define where the data are stored during execution, the targeted architecture is a distributed memory VLSI circuit. We describe a structural VHDL program for the matrix multiplication algorithm synthesised for a FPGA platform using these design principles. Our results show that the complexity added in each processor by the memories and the control is moderate and justifies in practice the use of such architectures

    Abstract

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    This paper introduces basic principles for extending the classical systolic synthesis methodology to multi-dimensional time. Multi-dimensional scheduling enables complex algorithms that do not admit linear schedules to be parallelized, but it also implies the use of memories in the architecture. The paper explains how to obtain compatible allocation and memory functions for vlsi (or simd-like code) generation. It also presents an original mechanism for controlling a vlsi architecture which has a multi-dimensional schedule. A structural vhdl code has been derived and synthesized (for implementation on fpga platform) using these systematic design principles. These results are preliminary steps to the possibility of a systematic hardware synthesis for multi-dimensional time

    The FloWatt Project

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    Fiche de suivi : pour qui ? Pourquoi ? Comment ?

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    EPS et évaluation. Une fiche bilan doit accompagner l'élève tout au long de l'année et du cursus lycéen, permettant de 'renseigner l'élève et les familles sur le niveau atteint en éducation physique et sportive'. Utilité et construction de cette fiche de suiv
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