Incidence des leucémies de l'enfant en fonction de la proximité et des caractéristiques générales de diverses sources d'expositions environnementales

Le rôle de l'environnement dans l'étiologie des leucémies aigües de l enfant (LA) fait aujourd'hui l'objet de recherches intenses. Dans ce contexte, le présent travail a pour objectif d étudier la relation entre l incidence de LA et la proximité des centrales nucléaires de production d électricité (CNPE) et des lignes à haute tension (LHT). Avant cette analyse fine, un premier travail a consisté à étudier les variations départementales de l'incidence de LA.Les cas inclus dans ces études sont toutes les LA du Registre National des Hémopathies malignes de l Enfant sur la période étudiée : 1990-2004 pour l étude de l incidence départementale et 2002-2007 pour les études de l association avec les facteurs d exposition environnementale. Dans l approche cas-témoins principalement utilisée pour ces dernières, les 30 000 sujets témoins constitue un échantillon représentatif de la population pédiatrique française sur la période d intérêt. D autre part, la géolocalisation des adresses des sujets et des sources d'exposition permet de définir des critères de proximité en relation avec la probabilité et/ou l'intensité d'exposition aux facteurs d'intérêt. L étude des LA par département n a pas mis en évidence de tendance ni de structure spatiale dans l incidence à ce niveau géographique : que ce soit globalement, par classe d âge, par sexe ou par sous-type de leucémie. Sur la période 2002-2007 contrairement aux périodes précédentes, un quasi-doublement de l incidence des LA à moins de 5 km des CNPE a été mis en évidence, avec une approche cas-témoin comme avec l étude d incidence. Ce résultat n était pas spécifique d une CNPE ou d un type de CNPE et non lié à la cartographie des émissions aériennes de radioactivité par les CNPE. L association trouvée entre l incidence de LA et la proximité aux LHT de plus de 225 kV (<50 m) semble restreinte aux enfants de moins de 5 ans ou n habitant en milieu urbain ; aucune association n a été trouvée avec la proximité aux LHT de moins de 150 kV.The role of the environment in the etiology of childhood acute leukemia (AL) is currently investigated. In this context, the aim of the present work is to study the association between the incidence of AL and the proximity no nuclear power plants (NPP) and to high voltage overhead power lines (HV OLs). At first, the geographical variations of AL have been studied at the Département level.The cases included in the studies are all cases of AL of the French National Registry of Childhood Haemopatopoietic Malignancies on the studied periods: 1990-2004 for the study of incidence on Départements and 2002-2007 for the studies of association between incidence of AL and environmental exposure factors. Concerning those latter studies, a case-control approach has been used. The control sample, representative of the French pediatric population, contains 30,000 subjects and has been drawn by the INSEE. The precise localization of addresses of subjects and of exposure sources in relation with the type of sources is essential to build indicators of exposure reflecting the probability and intensity of exposure. The study of AL by Département has highlighted neither trend nor spatial structure in the incidence at this geographical level globally as well as by age, gender and subtype of leukemia. On 2002-2007, on the contrary of on previous periods, the incidence of AL at less than 5 km from a NPP was nearly twice higher than expected, with the case-control study as well as with the incidence approach. This result was not specific to any age group, NPP, a type of NPP and was not associated with the geographic zoning of gaseous discharges of NPPs. The study of the proximity to HV OLs highlighted an association between the incidence of AL and the close proximity (< 50 m) of lines of more than 225 kV, association which was restricted to children of less than 5 y.o. or living in non-urban areas; but not with the proximity to lines of less than 150 kV.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

La caméline, une plante modèle pour la recherche translationnelle

National audienceEn biologie végétale, la recherche translationnelle vise à accélérer la valorisation de découvertes scientifiques réalisées à partir de plantes modèles au bénéfice de plantes d’intérêt agronomique. Dans ce domaine, la caméline est un outil particulièrement efficace : génétiquement proche de l’espèce modèle Arabidopsis thaliana, elle permet d’évaluer simplement de nouveaux caractères associés aux plantes oléoprotéagineuses

Model of mechanism behavior for verification of PLC programs

More extensive work on formal methods is now available for checking PLC (Programmable Logic Controller) programs. To verify a PLC program, it is necessary to consider a set of properties to prove and one of the most interesting problems that the designers must deal is to deduce a set of properties that traduces all the safety requirements of the system behavior. In this paper, we explore the contribution of such a plant model within the context of deduction, in a systematized way, of a set of properties to prove, verifying the PLC program. Our study is primarily experimental in nature and based on a case study. A set of properties to be checked based on detailed plant model is proposed. We then analyze how a Symbolic Model-Checking tool (the NuSMV has been selected) ensures verification of these properties either with or without the considered plant model

Water transfer and crack regimes in nano-colloidal gels

International audienceDirect observations of the surface and shape of model nano-colloidal gels associated with measurements of the spatial distribution of water content during drying show that air starts to significantly penetrate the sample when the material stops shrinking. We show that whether the material fractures or not during desiccation, as air penetrates the porous body, the water saturation decreases but remains almost homogeneous throughout the sample. This air-invasion is at the origin of another type of fracture due to capillary effects; these results provide a new insight in the liquid dynamics at the nano-scale. PACS number(s): 47.56.+r, 68.03.Fg, 81.40.N

Residential exposure to solar ultraviolet radiation and incidence of childhood hematological malignancies in France

Few studies have investigated the relationship between solar ultraviolet radiation (UV) and childhood hematological malignancies (CHM). This study addresses the associations between residential UV exposure at diagnosis and the incidence of types and subtypes of CHM, by age and gender, in France, over a long period, on the fine scale of the 36,326 Communes that constitute mainland France. The 9,082 cases of acute leukemia and 3,563 cases of lymphoma diagnosed before the age of 15 years from 1990 to 2009 were provided by the French National Registry of Childhood Hematological Malignancies. The incidence of CHM was calculated by Commune, year, age and gender and expressed as the standardized incidence ratio (SIR). UV data from 1988 to 2007 were extracted from the EUROSUN database. The annual daily average UV exposure of the children ranged from 85.5 to 137.8 J/cm2. For each additional 25 J/cm2, there was a significant increase in precursor B-cell acute lymphoblastic leukemia (PBC-ALL) in children aged less than 5 years (SIR 1.18; 95 % CI 1.10–1.27). Further analysis of PBC-ALL in the young children suggested a better fit of models with a threshold, with the risk increasing above 100 J/cm2, for which the SIR was 1.24 (95 % CI 1.14–1.36) for a 25 J/cm2 increase. The results remained stable in analyses stratifying by deprivation index or degree of urbanization of the Communes. The study suggests that higher residential UV exposure may be positively associated with a higher incidence of PBC-ALL in early childhood

Online Scheduling with Redirection for Parallel Jobs

International audienceAn important component of High Performance Computing (HPC) clusters is the job scheduling algorithm, which decides the allocation and the scheduling of the jobs in the system. Such scheduling algorithms need to be scalable to confront the growth both in size and in complexity of the modern clusters. We propose in this paper a new algorithm for scheduling parallel jobs with redirection. Specifically, our algorithm redirects the jobs whose execution affects significantly an important number of other jobs. A redirected job is stopped and restarted from the beginning in a dedicated part of the cluster. We show the effectiveness of our method through an intensive experimental campaign of simulations of production cluster log traces

Mechanical characterization and comparison of different NiTi/silicone rubber interfaces

International audienceThis paper investigates the effects of different surface treatments on the mechanical resistance of interface between wires of NiTi shape memory alloy and silicone rubber. Three different treatments were used; primer, plasma and combination of both. The wires deoxidation effects have also been studied. In order to characterize the interface properties in such composite material, pull-out tests were carried out by means of a home-made device. This test allows us to evaluate the mechanical resistance of the interface in terms of the maximum force reached during the test. First, results show that the debonding force is not higher after the wires deoxidation. This preparation is therefore not necessary. Second, using a primer PM820 and plasma separately leads to a significant improvment of the mechanical resistance. Third, the combination of these treatments (primer followed by plasma) and a longer time of exposure to the plasma alone get the debonding force higher. Consequently, NiTi/silicone rubber interface improved only by means of plasma offers a new way to obtain biocompatible interfaces in such composite material

Towards a reasoned 1-D river model calibration

Le calage de modèle reste une étape critique de la modélisation numérique. Après de nombreuses tentatives d`automatisation de cette tâche dans différentes domaines liés à l`eau, des questions se posent encore sur la nécessité de caler des modèles à base physique. Cet article propose aux utilisateurs de codes de calcul en hydraulique un cadre pour réaliser cette tâche selon un « code de bonnes pratiques ». Ce cadre comporte une formalisation des objets manipulés en hydraulique fluviale 1-D ainsi qu`une description conceptuelle générique du processus de calage. Ces deux éléments ont été implémentés dans un système à base de connaissances, intégrant un code de calcul ainsi que des connaissances d`experts sur le calage de modèle. Un prototype de système d`assistance au calage a ensuite été construit à l`aide d`un code de calcul résolvant les équations de Saint-Venant dans des rivières à lit fixe. Le cadre fourni pour le calage de modèle est composé de trois niveaux indépendants reliés respectivement à la tâche générique, au domaine d`application, et au code de calcul lui-même. Les deux premiers niveaux de connaissances peuvent ainsi aisément être réutilisés pour construire des systèmes d`assistance au calage pour d`autres domaines d`application, comme l`hydraulique 2-D ou encore la modélisation hydrologique à base physique. / Model calibration remains a critical step in numerical modelling. After many attempts to automate this task in water-related domains, questions about the actual need for calibrating physics-based models are still open. This article proposes a framework for good model calibration practice for end-users of 1-D hydraulic simulation codes. This framework includes a formalisation of objects used in 1-D river hydraulics along with a generic conceptual description of the model calibration process. It was implemented within a knowledge-based system integrating a simulation code and expert knowledge about model calibration. A prototype calibration support system was then built up with a specific simulation code solving subcritical unsteady flow equations for fixed-bed rivers. The framework for model calibration is composed of three independent levels related respectively to the generic task, to the application domain, and to the simulation code itself. The first two knowledge levels can thus easily be reused to build calibration support systems for other application domains, like 2-D hydrodynamics or physics-based rainfall-runoff modelling

River model calibration, from guidelines to operational support tools

Numerical modelling is now used routinely to make predictions about the behaviour of environmental systems. Model calibration remains a critical step in the modelling process and different approaches have been taken to develop guidelines to support engineers and scientists in this task. This article reviews currently available guidelines for a river hydraulics modeller by dividing them into three types: on the calibration process, on hydraulic parameters, and on the use of hydraulic simulation codes. The article then presents an integration of selected guidelines within a knowledge-based calibration support system. A prototype called CaRMA-1 (Calibration of River Model Assistant) has been developed for supporting the calibration of models based on a specific 1D code. Two case studies illustrate the ability of the prototype to face operational situations in river hydraulics engineering, for which both data quality and quantity are not sufficient for an optimal calibration. Using CaRMA-1 allows the modeller to achieve the calibration task in accordance with good calibration practice implemented in the knowledge base. Relevant reasoning rules can easily be added to the knowledge base to extend the prototype range of applications. This study thus provides a framework for building operational support tools from various types of existing engineering guidelines

A dietary supplementation with leucine and antioxidants is capable to accelerate muscle mass recovery after immobilization in adult rats

Prolonged inactivity induces muscle loss due to an activation of proteolysis and decreased protein synthesis; the latter is also involved in the recovery of muscle mass. The aim of the present work was to explore the evolution of muscle mass and protein metabolism during immobilization and recovery and assess the effect of a nutritional strategy for counteracting muscle loss and facilitating recovery. Adult rats (6-8 months) were subjected to unilateral hindlimb casting for 8 days (10-18) and then permitted to recover for 10 to 40 days (R10-R40). They were fed a Control or Experimental diet supplemented with antioxidants/polyphenols (AOX) (10 to 18), AOX and leucine (AOX + LEU) (18 to R15) and LEU alone (R15 to R40). Muscle mass, absolute protein synthesis rate and proteasome activities were measured in gastrocnemius muscle in casted and non-casted legs in post prandial (PP) and post absorptive (PA) states at each time point. Immobilized gastrocnemius protein content was similarly reduced (-37%) in both diets compared to the non-casted leg. Muscle mass recovery was accelerated by the AOX and LEU supplementation (+6% AOX+LEU vs. Control, P<0.05 at R40) due to a higher protein synthesis both in PA and PP states (+23% and 31% respectively, Experimental vs. Control diets, P<0.05, R40) without difference in trypsin-and chymotrypsin-like activities between diets. Thus, this nutritional supplementation accelerated the recovery of muscle mass via a stimulation of protein synthesis throughout the entire day (in the PP and PA states) and could be a promising strategy to be tested during recovery from bed rest in humans