Développement d'une modélisation hydrologique incluant la représentation des aquifères : évaluation sur la France et à l'échelle globale

L'impact des eaux souterraines sur le bilan d'eau en surface et sur le climat a récemment fait l'objet de plusieurs études. Dans cette thèse, un schéma d'aquifère simplifiée à été développé dans le système hydrologique continental ISBA-TRIP utilisé au CNRM et évalué sur la France et à l'échelle globale. D'abord implémenté dans le modèle de routage TRIP, ce schéma a permis d'améliorer la comparaison entre les débits simulés et observés. La bonne comparaison des stocks d'eau simulées avec les estimations du satellite GRACE a en outre confirmé la cohérence des nappes d'eau simulées. Le principal effet des aquifères est d'introduire un temps de résidence qui décale et lisse les variables hydrologiques simulées. L'introduction des remontées capillaires de la nappe vers le sol d'ISBA a nécessité l'utilisation de la version explicite et multi-couche du schéma de sol d'ISBA. Son évaluation sur la France et à l'échelle globale a démontré l'intérêt d'une représentation plus physique des processus hydrologiques du sol en améliorant significativement les débits et stocks d'eau simulés. Le principal effet des remontées capillaires est d'augmenter l'évapotranspiration en période sèche. Cette évaluation révèle cependant un manque de dynamisme tendant à sous-estimer les débits moyens annuels et à augmenter la sensibilité d'ISBA à la résolution. Il reste en outre de nombreuses incertitudes. Certaines paramétrisations sont discutables et nécessiteraient sans doute d'être améliorées ou corrigées. L'objectif ultime de ces travaux sera l'introduction du système complet ISBA-TRIP dans le modèle de climat du CNRM afin d'évaluer l'impact des aquifères sur la simulation du climat récent et futur. ABSTRACT : The impact of groundwater on surface water budget and climate has recently received increasing attention. In this thesis, a simple groundwater scheme is developed in the continental hydrological system ISBA-TRIP used at Météo France, and evaluated over France and at global scale. This scheme has been first introduced in the TRIP river routing model. It improves the comparison between observed and simulated river discharges. The good comparison between simulated terrestrial water storage and estimates of the GRACE satellite mission confirms the coherence of the simulated water table heads. The main effect of groundwater is to introduce a time lag which shifts and smooths the simulated hydrological variables. The introduction of the capillary rises from the water table to the soil requires the use of the explicit multi-layer scheme soil of ISBA. His evaluation over France demonstrates the relevance of a more physically-based representation of the soil hydrological processes by improving the simulated river discharges and terrestrial water storages. The main effect of capillary rises is to increase the evapotranspiration during dry periods. However, this evaluation point out a lack of dynamism which leads to underestimate the mean annual river discharges and to increase the sensitivity to the resolution. Moreover, numerous uncertainties still remain. Some parameterizations are questionable and would require to be improved. The ultimate objective will be to introduce the fully-coupled ISBA-TRIP system into the CNRM global climate model in order to assess the relevance of groundwater processes for the simulation of both recent and future climates

Maximal wall shear stress in arterial stenoses: application to the internal carotid arteries

Maximal wall shear stress (MWSS) in the convergent part of a stenosis is calculated by the interactive boundary-layer theory. A dimensional analysis of the problem shows that MWSS depends only on a few measurable parameters. A simple relationship between MWSS and these parameters is obtained, validated, and used to calculate the magnitude of MWSS in a carotid stenosis, as a function of the patency of the circle of Willis and the stenotic pattern. This demonstrates the huge effect of collateral pathways. Elevated MWSS are observed even in moderate stenoses, provided they are associated with a contralateral occlusion, a large anterior, and narrow posterior communicating arteries, suggesting a potential risk of embolus release in this configuration

Antioxidant activity of phenolic acids and esters present in red wine on human Low-Density Lipoproteins

To evaluate the antioxidant activity of different phenolic acids and their esters, three types of experiments have been used. Electron paramagnetic resonance (EPR) quantitative analysis was carried out using the acetaldehyde/xanthine oxidase system and Fenton's reaction to generate superoxide and hydroxyl radicals, respectively. In a second test, hydroperoxides generated by Cu2+-catalysed oxidation of low density lipoproteins (LDL) were quantified by a modified iodometric method. In a third assay, LDL were oxidized with Esterbauer's method and modified LDL species were quantified by HPLC. The results show that the esterified phenolic derivatives present a better antioxidant activity, on the lipoperoxidation of LDL, than the corresponding phenolic acids

Periodontal treatment to improve glycaemic control in diabetic patients: study protocol of the randomized, controlled DIAPERIO trial

<p>Abstract</p> <p>Background</p> <p>Periodontitis is a common, chronic inflammatory disease caused by gram-negative bacteria leading to destruction of tissues supporting the teeth. Epidemiological studies have consistently shown increased frequency, extent and severity of periodontitis among diabetic adults. More recently, some controlled clinical trials have also suggested that periodontal treatment could improve glycaemic control in diabetic patients. However current evidence does not provide sufficient information on which to confidently base any clinical recommendations. The main objective of this clinical trial is to assess whether periodontal treatment could lead to a decrease in glycated haemoglobin levels in metabolically unbalanced diabetic patients suffering from chronic periodontitis.</p> <p>Methods</p> <p>The DIAPERIO trial is an open-label, 13-week follow-up, randomized, controlled trial. The total target sample size is planned at 150 participants, with a balanced (1:1) treatment allocation (immediate treatment vs delayed treatment). Periodontal treatment will include full mouth non-surgical scaling and root planing, systemic antibiotherapy, local antiseptics (chlorhexidine 0.12%) and oral health instructions. The primary outcome will be the difference in change of HbA1c between the two groups after the 13-weeks' follow-up. Secondary outcomes will be the difference in change of fructosamine levels and quality of life between the two groups.</p> <p>Discussion</p> <p>The DIAPERIO trial will provide insight into the question of whether periodontal treatment could lead to an improvement in glycaemic control in metabolically unbalanced diabetic patients suffering from periodontitis. The results of this trial will help to provide evidence-based recommendations for clinicians and a draft framework for designing national health policies.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN15334496</p

Development of a hydrological model including groundwater : evaluation over France and at global scale

L'impact des eaux souterraines sur le bilan d'eau en surface et sur le climat a récemment fait l'objet de plusieurs études. Dans cette thèse, un schéma d'aquifère simplifiée à été développé dans le système hydrologique continental ISBA-TRIP utilisé au CNRM et évalué sur la France et à l'échelle globale. D'abord implémenté dans le modèle de routage TRIP, ce schéma a permis d'améliorer la comparaison entre les débits simulés et observés. La bonne comparaison des stocks d'eau simulées avec les estimations du satellite GRACE a en outre confirmé la cohérence des nappes d'eau simulées. Le principal effet des aquifères est d'introduire un temps de résidence qui décale et lisse les variables hydrologiques simulées. L'introduction des remontées capillaires de la nappe vers le sol d'ISBA a nécessité l'utilisation de la version explicite et multi-couche du schéma de sol d'ISBA. Son évaluation sur la France et à l'échelle globale a démontré l'intérêt d'une représentation plus physique des processus hydrologiques du sol en améliorant significativement les débits et stocks d'eau simulés. Le principal effet des remontées capillaires est d'augmenter l'évapotranspiration en période sèche. Cette évaluation révèle cependant un manque de dynamisme tendant à sous-estimer les débits moyens annuels et à augmenter la sensibilité d'ISBA à la résolution. Il reste en outre de nombreuses incertitudes. Certaines paramétrisations sont discutables et nécessiteraient sans doute d'être améliorées ou corrigées. L'objectif ultime de ces travaux sera l'introduction du système complet ISBA-TRIP dans le modèle de climat du CNRM afin d'évaluer l'impact des aquifères sur la simulation du climat récent et futur.The impact of groundwater on surface water budget and climate has recently received increasing attention. In this thesis, a simple groundwater scheme is developed in the continental hydrological system ISBA-TRIP used at Météo France, and evaluated over France and at global scale. This scheme has been first introduced in the TRIP river routing model. It improves the comparison between observed and simulated river discharges. The good comparison between simulated terrestrial water storage and estimates of the GRACE satellite mission confirms the coherence of the simulated water table heads. The main effect of groundwater is to introduce a time lag which shifts and smooths the simulated hydrological variables. The introduction of the capillary rises from the water table to the soil requires the use of the explicit multi-layer scheme soil of ISBA. His evaluation over France demonstrates the relevance of a more physically-based representation of the soil hydrological processes by improving the simulated river discharges and terrestrial water storages. The main effect of capillary rises is to increase the evapotranspiration during dry periods. However, this evaluation point out a lack of dynamism which leads to underestimate the mean annual river discharges and to increase the sensitivity to the resolution. Moreover, numerous uncertainties still remain. Some parameterizations are questionable and would require to be improved. The ultimate objective will be to introduce the fully-coupled ISBA-TRIP system into the CNRM global climate model in order to assess the relevance of groundwater processes for the simulation of both recent and future climates

Impactos dos níveis fluviais na simulação e trocas rio–aquíferos sob o aquífero aluvial do Reno Superior (França/Alemanha)

International audienceThis study aims to assess the sensitivity of river level estimations to the stream-aquifer exchanges within a hydrogeological model of the Upper Rhine alluvial aquifer (France/Germany), characterized as a large shallow aquifer with numerous hydro-power dams. Two specific points are addressed: errors associated with digital elevation models (DEMs) and errors associated with the estimation of river level. The fine-resolution raw Shuttle Radar Topographic Mission dataset is used to assess the impact of the DEM uncertainties. Specific corrections are used to overcome these uncertainties: a simple moving average is applied to the topography along the rivers and additional data are used along the Rhine River to account for the numerous dams. Then, the impact of the river-level temporal variations is assessed through two different methods based on observed rating curves and on the Manning formula. Results are evaluated against observation data from 37 river-level points located over the aquifer, 190 piezometers, and a spatial database of wetlands. DEM uncertainties affect the spatial variability of the stream-aquifer exchanges by inducing strong noise and unrealistic peaks. The corrected DEM reduces the biases between observations and simulations by 22 and 51% for the river levels and the river discharges, respectively. It also improves the agreement between simulated groundwater overflows and observed wetlands. Introducing river-level time variability increases the stream-aquifer exchange range and reduces the piezometric head variability. These results confirm the need to better assess river levels in regional hydrogeological modeling, especially for applications in which stream-aquifer exchanges are important

Phénoménologie de la douleur persistante (PHEDOU) (Production par le malade d'un discours d'inspiration phénoménologique sur son vécu douloureux et sur sa maladie - Etude de l'effet de ce discours sur l'état douloureux et caractérisation de ce vécu)

Pour vérifier des hypothèses tirées d'écrits phénoménologiques sur la douleur et la souffrance, 137 patients se sont prêtés à deux entretiens successifs sur leur vécu quotidien de la douleur. L'étude PHEDOU comprend deux parties. La première portait sur l'acceptabilité du premier entretien et ses effets sur la douleur chez 63 patients cancéreux, face à 8 autres cancéreux n'ayant pas eu cet entretien. Ceci a permis de confirmer l'excellente tolérance de cet entretien, mais n'a pas permis de mettre en évidence son effet bénéfique sur les douleurs. La seconde partie a contrasté le vécu de 74 cancéreux à celui de 40 lombosciatalgiques. A partir des termes employés par les patients, nous avons élaboré deux discours correspondant à deux groupes de patients ne se différenciant ni par le sexe, ni par leur région. Nous les avons qualifiés l'un d'envahi, et l'autre d'adapté. Ces deux discours pourraient être proposés à d'autres patients douloureux pour qu'ils déterminent duquel ils participent.This study was designed in order to test some hypotheses derived from phenomenological works on pain and suffering. It includes 137 patients who participated in two interviews on their daily conscious life with pain. In a first part, we analysed the acceptability of the first interview and its effects on pain in 63 patients with cancer, compared to 8 other patients who did not have such an interview. This was particularly welcome, but had no beneficial effect on pain. The second part described the daily conscious life with pain of 74 patients with cancer and of 40 patients with chronic lumbosciatica. Using the proper terms of the patients, we were able to construct two different discourses, we qualified overcome and adapted respectively. These discourses, which are independant of sex and area of inclusion, could be proposed to new patients with pain to identify quickly the group they belong.PARIS5-BU Méd.Cochin (751142101) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Etude quantitative tridimensionnelle du réseau micro-vasculaire du cortex cérébral humain

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Gestão otimizada das águas subterrâneas aplicado a um campo de poços de alto rendimento (10 M m3/ano) na França

International audienceThe strong impact of population increase and the effects of climate change on drinking-water resources mean that it is essential to optimize the management of groundwater. This study aims at determining the best way of sustainably exploiting a well field south of Bordeaux (France). Currently, the field’s 18 wells can produce about 10 million (M) m3/year. Starting from a complete review of field data, this study presents an optimization method with surrogate models based on a preexisting spatially distributed groundwater model. This uses ‘influence coefficient’ methods for designing an efficient strategy to exploit groundwater, while preserving it from aquifer dewatering. This optimization approach investigates a much larger number of combinations than the classic trial-and-error approach. Though it is usually considered that preserving groundwater quality necessarily implies restricted exploitation, this work shows that other exploitation strategies can reach this objective with a significant gain in the total extracted volume without creating new wells. Two alternative configurations, incorporating the creation of new wells, were tested for maximizing the capacity of the well field and optimizing the effective capacity of the existing pipe network. Substantial gains are expected from those configurations, reaching an additional 2.2–5.5 M m3/year.L’impact important de l’augmentation de la population et des effets du changement climatique sur les ressources en eau potable rend essentielle l’optimisation de la gestion des eaux souterraines. Cette étude vise à déterminer la meilleure façon d’exploiter durablement un champ captant au sud de Bordeaux (France). Actuellement, les 18 puits de ce champ captant peuvent produire jusqu’à 10 millions de m3 par an. En se basant sur un examen complet des données de terrain, cette étude présente une méthode d’optimisation avec un modèle équivalent simplifié basé sur un modèle hydrodynamique distribué préexistant. Il s’agit d’utiliser la méthode des “coefficients d’influence” pour concevoir une stratégie efficace d’exploitation des eaux souterraines tout en préservant l’aquifère du dénoyage. Cette approche d’optimisation permet de considérer un nombre beaucoup plus grand de combinaisons que l’approche classique par essai-erreur. Bien qu’il soit généralement considéré que la préservation de la qualité des eaux souterraines implique nécessairement une exploitation modérée, ces travaux montrent que d’autres stratégies d’exploitation peuvent atteindre cet objectif avec un gain significatif sur le volume total exploité sans créer de nouveaux puits. Par ailleurs, deux configurations alternatives, intégrant la création de nouveaux puits, ont été testées pour maximiser la capacité du champ captant et utiliser pleinement le réseau d’adduction existant. Des gains substantiels sont attendus de ces configurations, atteignant 2.2–5.5 M3 supplémentaires par an