Philippe Zittoun: la fabrique des politiques publiques

La fabrique des politiques propose une réflexion à la fois érudite, novatrice et controversée dans le champ de l'analyse des politiques publiques, soit trois bonnes raisons pour lire cet ouvrage et pour imaginer, peut-être, les prémices d'un tournant narratif en science politique

Combined use of seismic, isotopic and piezometrics data to reduce uncertainty in models

International audienceTo improve modelling of complex multi-aquifer systems, a better understanding of To improve modelling of complex multi-aquifer systems, a better understanding of reservoirs’s geometry and an improvement of calibration are required. Combining seismic data, isotopic analysis and piezometrics measurements is a way to improve flow simulation.In Gironde (France), many hydrodynamics models have been developed to guide choices in groundwaters exploitation. They put into evidence a lack of knowledge on the Villagrains-Landiras structure corresponding to a potential recharge area for the aquifers of the region. To correct these shortcomings, a detailed study of this area was undertaken to measure its potential for exploitation.Three exploratory wells reaching depths ranging from 200 to 350 m have been drilled to refine the structural vision of the region and to delimitate the various erosional gaps.To improve significantly the knowledge of the reservoirs’s geometry, seismic reflection has been used to obtain a high-resolution image of the subsoil. A total of 15 seismic lines have been used, representing a total length of 248 km. At first, 13 old lines, coming from oil prospecting, have been reprocessed to maximize the definition of hydrostratigraphic units in the first 300 meters. Then, two news high-resolution seismic lines have been achieved in September 2007 on a total length of 17.5 km. This geological survey has helped us to constrain the pattern of the various aquifers of the structure. It has also enabled us to adjust the elevation of the tops and bottoms used in the hydrodynamic model.The aim of the hydrogeological study was to characterize the hydrodynamic mechanisms affecting the Villagrains-Landiras structure. The design of water level maps allowed us to study the distribution of hydraulic heads in comparison to the structure and to measure its potential influence on the recharge of groundwaters. The analysis of the piezometrics fluctuations underlined many similar variations which characterize locals behaviour. Isotopic analysis (18O, 2H, 3H, 13C, 14C), allow us to study the recharge, to confirm the influence of the structure in this process and to constrain residence time in the model. This important part of the study involves the interpretation of analysis coming from 4 different aquifers, sampled in 21 wells located on the structure and its near vicinity.This multidisciplinary approach, based on the interpretation of seismic, isotopic and piezometric data, helped us to improve the knowledge of the structural arrangement of the aquifers and the understanding of the hydrodynamic processes to simulate more efficiently flows in the model

Quality of abstracts in 3 clinical dermatology journals

Background Structured abstracts have been widely adopted in medical journals, with little demonstration of their superiority over unstructured abstracts.Objectives: To compare abstract quality among 3 clinical dermatology journals and to compare the quality of structured and unstructured abstracts within those journals. Design and Data Sources: Abstracts of a random sample of clinical studies (case reports, case series, and reviews excluded) published in 2000 in the Archives of Dermatology, The British Journal of Dermatology, and the Journal of the American Academy of Dermatology were evaluated. Each abstract was rated by 2 independent investigators, using a 30-item quality scale divided into 8 categories (objective, design, setting, subjects, intervention, measurement of variables, results, and conclusions). Items applicable to the study and present in the main text of the article were rated as being present or absent from the abstract. A global quality score (range, 0-1) for each abstract was established by calculating the proportion of criteria among the eligible criteria that was rated as being present. A score was also calculated for each category. Interrater agreement was assessed with a {kappa} statistic. Mean ± SD scores were compared among journals and between formats (structured vs unstructured) using analysis of variance. Main Outcome Measures: Mean quality scores of abstracts by journal and by format. Results: Interrater agreement was good ({kappa} = 0.71). Mean ± SD quality scores of abstracts were significantly different among journals (Archives of Dermatology, 0.78 ± 0.07; The British Journal of Dermatology, 0.67 ± 0.17; and Journal of the American Academy of Dermatology, 0.64 ± 0.15; P = .045) and between formats (structured, 0.71 ± 0.11; and unstructured, 0.56 ± 0.18; P = .002). The setting category had the lowest scores. Conclusions: The quality of abstracts differed across the 3 tested journals. Unstructured abstracts were demonstrated to be of lower quality compared with structured abstracts and may account for the differences in quality scores among the journals. The structured format should be more widely adopted in dermatology journals

A new numerical strategy for SPF pressure profile computing based on statistical strain rate controlling

International audienceThis paper investigates the designing of Superplastic Forming pressure cycles in order to propose rapid forming sequences that suit industrial strategy, and which enable the control of microstructure evolutions. An optimization algorithm using ABAQUS® coupled with MATLAB® has been developed in order to improve forming cycles while allowing superplasticity. The numerical strategy is based on an algorithm controlling a statistical maximum of the distribution of strain rate of non-formed elements of part mesh instead of the maximum strain rate on the whole mesh for classical optimization algorithms. The objective of this method is to exclude numerical singularities that are used for pressure controlling in traditional techniques. This paper details firstly the new algorithm and then presents numerical and experimental results for different forming conditions obtained from industrial, classical, and optimized pressure cycles. These tests were performed on Ti-6Al-4V titanium alloys

Production de biohydrogène par électro-catalyse microbienne

La cellule d électrolyse microbienne (CEM) permet la conversion de la biomasse en dihydrogène via un apport théorique en énergie électrique 10 fois moindre que celui de l électrolyse de l eau. Un tel procédé fonctionne via la technologie des bioanodes, qui permet la catalyse de l oxydation de la biomasse en CO2 par l intermédiaire d un biofilm électro-actif. Les travaux exposés dans ce manuscrit de thèse ont pour but l optimisation des performances de la bioanode, la compréhension des mécanismes de catalyse et la réalisation d un prototype à échelle laboratoire. L optimisation par l étude de paramètres opératoires en montage 3 électrodes a montré que l utilisation de sédiments de salins comme source de micro-organismes avec électrode en feutre de carbone polarisée à + 0,1 V / ECS à une température de 40C permet la formation de bioanodes capables de débiter jusqu à 85 A.m-2 pour une conductivité de 10,4 S.m-1. A 30C, le pyroséquençage ADN a mis en lumière l émergence des genres bactériens Desulfuromonas et Marinobacter. La conception et l exploitation d un modèle de voltammétrie cyclique a montré que le transport des électrons au sein du biofilm était environ 100 fois plus lent que le métabolisme bactérien. L utilisation de la spectroscopie d impédance électrochimique montre que la résistance au transfert de charge à l interface électrode/solution baisse de 24 k .cm2 à 64 .cm2 lors de la formation du biofilm. Un taux de production maximum de 2,85 LH2.L-1.j-1 ainsi qu une durée de vie de plus de 50 jours du procédé ont été obtenus lors de la conduite d un prototype laboratoire de CEM.Microbial electrolysis cell (MEC) is a recent and promising bioelectrochemical process that converts biomass onto hydrogen thanks to an amount of electrical energy 10 times smaller than for water electrolysis. The operation of the process is making possible by the bioanode technology which catalyses the biomass combustion onto CO2 through an electro-active biofilm. The purpose of the present work consists on the optimisation of the bioanode, the understanding of the catalysis mechanism and a scaling-up by the designing of a MEC prototype. Using a three-electrode device and sediment of salt marshes as inoculum, the study of the experimental parameters demonstrated that carbon felt poised at + 0.1 V /ECS at 40C led to the formation of bioanode able to generate up to 85 A.m-2 at a solution conductivity of 10,4 S.m-1. For a temperature of 30C, DNA pyrosequencing denoted the presence of the two bacterial genera Desulfuromonas and Marinobacter. The development and the exploitation of a cyclic voltammetric model showed that electron transfer within the biofilm ran almost 100 times slower than bacterial metabolism. Electrochemical impedance spectroscopy during biofilm formation revealed a decreasing of the charge transfer resistance at the electrode/solution interface from 24 k .cm2 to 64 .cm2. Designing and first experiments with a 6L CEM prototype led to a hydrogen production rate of 2.85 LH2.L-1.j-1 and a process life time of up to 50 days. Those performances were achieved in a reproducible way.TOULOUSE-INP (315552154) / SudocSudocFranceF

Comparison of Characteristics of Neuropathic and Non-neuropathic Pruritus to Develop a Tool for the Diagnosis of Neuropathic Pruritus: The NP5

The diagnosis of neuropathic pruritus (NP) may be difficult. The aim of this study was to compare the characteristics of both neuropathic pruritus and non-neuropathic pruritus (NNP) in order to elaborate a tool to help the diagnosis of NP without clinical examination. One hundred and seven patients were included: Fifty three in the NP group and Fifty four in the NNP group. In multiple regression, presence of twinges, absence of burning, worsening with activity, no worsening with stress, and relief with cold ambient temperature were independent factors that were associated with NP. A score of two criteria out of five was optimal to discriminate NP from NNP with a sensitivity of 76% and a specificity of 77%. Alloknesis, hyperknesis, or the ice cube test were not included because their evaluation is based on clinical examination. Future high-powered studies are needed to confirm the results of the present study