Evaluation de l’exposition tabagique chez un groupe de « fumeurs actifs » et un groupe de « fumeurs passifs ».

La fumée de cigarette expose les fumeurs et leur entourage, à des substances chimiques toxiques responsables de maladies graves voire mortelles. L’évaluation de l’exposition au tabac permet d’apprécier le degré de dépendance et l’intensité de l’imprégnation tabagique.Notre étude porte sur l’évaluation de cette exposition chez un groupe de fumeurs chroniques et un groupe de « fumeurs passifs »et ceci par détermination des marqueurs du tabagisme :-Evaluer les taux de nicotine et de cotinine urinaires chez l’ensemble des sujets par chromatographie liquide haute performance (HPLC-DAD) utilisant une méthode d’extraction en phase solide (SPE) ;-Evaluer le taux de la carboxyhémoglobine chez ces sujets ; -Evaluer certains paramètres biochimiques (bilan lipidique et glycémie) et hémobiologiques (numération sanguine) chez ces sujets ; relever les perturbations éventuelles

Mécanisme de la réaction entre le diphényl mercure et le chlorure de méthyl mercure : étude par chromatographie en phase liquide

La chromatographie en phase liquide à polarité de phases inversée est utilisée pour élucider le mécanisme de l'action du diphényl mercure (DPM) sur le chlorure de méthyl mercure (CMM) Dans un premier temps, les organomercuriels sont élués avec une phase mobile constituée d’une solution méthanol/NaCl (0.05 M) dans le rapport volumique 70/30. Dans ces conditions, l’analyse quantitative du mélange réactionnel DPM+CMM montre qu’au bout de 10 minutes, la quantité de DPM devient constante De plus, les nombres de moles de DPM disparues et chlorure de phényl mercure (CRM) obtenues,sont égaux suggérant ainsi une réaction équilibrée entre le DPM et CMM.Le mécanisme de cette réaction est confirmé par une deuxième méthode. Elle consiste à complexer les organomercuriels de la réaction en incorporant la mercaptopurine dans la phase mobile suivante : méthanol/acétonitri1e/KH2PO4 0.005 M (1/4/5 en volume).Les constantes d’équilibre obtenues par les deux méthodes sont comparables

A runtime approach to dynamic resource allocation for sparse direct solvers

International audience—To face the advent of multicore processors and the ever increasing complexity of hardware architectures, pro-gramming models based on DAG-of-tasks parallelism regained popularity in the high performance, scientific computing com-munity. In this context, enabling HPC applications to perform efficiently when dealing with graphs of parallel tasks that could potentially run simultaneously is a great challenge. Even if a uniform runtime system is used underneath, scheduling multiple parallel tasks over the same set of hardware resources introduces many issues, such as undesirable cache flushes or memory bus contention. In this paper, we show how runtime system-based scheduling contexts can be used to dynamically enforce locality of parallel tasks on multicore machines. We extend an existing generic sparse direct solver to use our mechanism and introduce a new decomposition method based on proportional mapping that is used to build the scheduling contexts. We propose a runtime-level dynamic context management policy to cope with the very irregular behavior of the application. A detailed performance analysis shows significant performance improvements of the solver over various multicore hardware

Author manuscript, published in "Third International Workshop on Accelerators and Hybrid Exascale Systems (2013)" 1 Composing multiple StarPU applications over heterogeneous machines: a supervised approach

Abstract—Enabling HPC applications to perform efficiently when invoking multiple parallel libraries simultaneously is a great challenge. Even if a single runtime system is used underneath, scheduling tasks or threads coming from different libraries over the same set of hardware resources introduces many issues, such as resource oversubscription, undesirable cache flushes or memory bus contention. This paper presents an extension of StarPU, a runtime system specifically designed for heterogeneous architectures, that allows multiple parallel codes to run concurrently with minimal interference. Such parallel codes run within scheduling contexts that provide confined execution environments which can be used to partition computing resources. Scheduling contexts can be dynamically resized to optimize the allocation of computing resources among concurrently running libraries. We introduce a hypervisor that automatically expands or shrinks contexts using feedback from the runtime system (e.g. resource utilization). We demonstrate the relevance of our approach using benchmarks invoking multiple high performance linear algebra kernels simultaneously on top of heterogeneous multicore machines. We show that our mechanism can dramatically improve the overall application run time (-34%), most notably by reducing the average cache miss ratio (-50%). I

Effect of Dietary n-3 Polyunsaturated Fatty Acids on Oxidant/Antioxidant Status in Macrosomic Offspring of Diabetic Rats

The aim of this work was to determine the effect of dietary n-3 PUFA on oxidant/antioxidant status, in vitro very low and low density lipoprotein (VLDL-LDL), and VLDL-LDL-fatty acid composition in macrosomic pups of diabetic mothers. We hypothesized that n-3 PUFA would improve oxidative stress in macrosomia. Diabetes was induced in female Wistar rats fed with the ISIO diet (control) or with the EPAX diet (enriched in n-3 PUFAs), by streptozotocin. The macrosomic pups were killed at birth (day 0) and at adulthood (day 90). Lipid parameters and VLDL-LDL-fatty acid composition were investigated. The oxidant/antioxidant status was determined by measuring plasma oxygen radical absorbance capacity (ORAC), hydroperoxides, carbonyl proteins, and VLDL-LDL oxidation. Macrosomic rats of ISIO fed diabetic mothers showed an increase in plasma and VLDL-LDL-triglycerides and VLDL-LDL-cholesterol levels and altered VLDL-LDL-fatty acid composition. Plasma ORAC was low with high hydroperoxide and carbonyl protein levels. The in vitro oxidizability of VLDL-LDL was enhanced in these macrosomic rats. The EPAX diet corrected lipid parameters and improved oxidant/antioxidant status but increased VLDL-LDL susceptibility to oxidation. Macrosomia is associated with lipid abnormalities and oxidative stress. n-3 PUFA exerts favorable effects on lipid metabolism and on the oxidant/antioxidant status of macrosomic rats. However, there are no evident effects on VLDL-LDL oxidation