Managed aquifer recharge in weathered crystalline basement aquifers in India: Monitoring of the effect of tank infiltration on water quality over several monsoon events

International audienceManaged aquifer recharge (MAR) structures like percolation tanks are considered by the Indian national and regional governments as major option for tackling declining groundwater levels due to overexploitation for irrigation purposes (Boisson et al., 2014). Their main purpose is to restore groundwater availability under strong climatic and anthropogenic pressure. Furthermore, MAR-induced dilution with fresh surface water is generally expected to improve groundwater quality with respect to both anthropogenic and geogenic contaminants (total mineralisation, nitrates, chlorides, sulphates and fluoride contents). The impact of a percolation tank on groundwater quality was investigated in a context that is typical for hydro-climatic and geological settings in southern and eastern India: fractured crystalline basement aquifers overlain by a weathering zone under semi-arid climate. Water level data and geochemical indicators (stable isotopes and major ions) were monitored for both groundwater and surface water, over several successive monsoon events. In case of high to very high water levels, the groundwater quality is globally improved. However, in a few cases, the quality of the groundwater can be negatively impacted due to leaching of salts under the tank, particularly during the first rain events of the monsoon. Geogenic fluoride contents in groundwater, induced by water-rock interaction and enhanced by recycling of agricultural return flow under paddy fields, is found to be relatively stable over the year. This finding points out that the underlying processes, mainly dissolution of F-bearing phases like fluorapatites combined with Ca/Na cation exchange and calcite precipitation , both limiting the possibility of F-removal via fluorite precipitation (Pettenati et al., 2013, 2014), are not impacted by the hydrological conditions. This work highlights the complexity of the recharge processes in crystalline aquifers, enhanced by the variability of hydrological conditions. It also provides insights into the possible risk for groundwater quality deterioration in cases of light and short monsoons periods

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Semi-distributed lumped model of a karst system under active management

In this paper inverse modeling is used to characterize the regime of a karst aquifer subjected to extensive pumping in a conduit located upstream of its main outlet. The systemic approach uses a transfer model that is based on computing the convolution integral of up to several signals, e.g., efficient rainfall, pumping, to simulate flow rates and groundwater levels in both the karst conduit and the carbonate matrix at the aquifer outlet and in several parts of the catchment area. The model is a semi-distributed lumped model which simulates the hydrological response of a heterogeneous karst aquifer made up of different hydrologic compartments, and is applied to the Lez karst system, France. Groundwater is abstracted near the system’s major outlet at a higher rate than the low-water spring discharge, thereby mobilizing stored groundwater during low-water periods (‘active management’)

Multi-traçage de la Fontaine de Nîmes

Multi-tracing of Fontaine de Nîmes. The main outlet of the Nimes karst system is the Fontaine de Nimes spring. In the past, several tracing experiments have identified relationships between points supposed to be part of the recharge area of the system and the Fontaine de Nimes spring. Nevertheless, these tracing experiments suffered from a lack of breakthrough curves. In this paper, the results of a multi-tracing test realized in March 2006 from four injection points are described. The monitoring network of this experiment has been designed in order to characterize the respective roles of the three karst conduits (west karst conduit, north karst conduit and Galerie des Poteries) leading to the main spring. The major results are following : (i) all the dye tracers have been identified at the Fontaine de Nimes spring (ii) the west karst conduit plays a major role in the drainage of the recharge area of the karst system (iii) no dye tracer has been identified on the north karst conduit (iv) the discharge rate into the Galerie des Poteries, measured by dilution of salt upstream injected, is less than 50 l/min, the recharge area of this conduit is geographically very limited. We can notice that well-structured breakthrough curves have been obtained for three of the four tracers.Le système karstique des garrigues nîmoises possède un exutoire principal, la Fontaine de Nîmes. Par le passé, plusieurs essais de traçages ont permis de mettre en évidence les relations entre des points supposés de son bassin d'alimentation et la Fontaine de Nîmes. Ces essais manquaient cependant de courbes de restitution. Dans cet article, les résultats d'un multi-traçage effectué en mars 2006 à partir de quatre points d'injection sont présentés. Le réseau de surveillance de cet essai a été conçu de façon à caractériser les rôles respectifs des différents conduits karstiques reconnus menant à la source principale. Les résultats majeurs sont les suivants : (i) tous les traceurs ont été identifiés à la Fontaine de Nîmes ; (ii) le conduit karstique ouest joue un rôle majeur dans le drainage du bassin d'alimentation de la Fontaine ; (iii) aucun traceur n'est identifié sur le conduit karstique nord, laissant présager un rôle mineur dans le drainage des parties ouest et nord du bassin d'alimentation ; (iv) un débit très faible, mesuré par dilution, transite dans la galerie des Poteries dont le bassin d'alimentation est géographiquement très limité. Par ailleurs, des courbes de restitution bien structurées ont été observées pour trois des quatre essais.Marechal Jean-Christophe, Courtois Nathalie, Jouanen Gilbert, Meus Philippe. Multi-traçage de la Fontaine de Nîmes. In: Karstologia : revue de karstologie et de spéléologie physique, n°56, 2e semestre 2010. Cavités glaciaires de l'Himalaya et L'écroulement du porche de la grotte Chauvet. pp. 1-8

Multi-traçage de la Fontaine de Nîmes

Multi-tracing of Fontaine de Nîmes. The main outlet of the Nimes karst system is the Fontaine de Nimes spring. In the past, several tracing experiments have identified relationships between points supposed to be part of the recharge area of the system and the Fontaine de Nimes spring. Nevertheless, these tracing experiments suffered from a lack of breakthrough curves. In this paper, the results of a multi-tracing test realized in March 2006 from four injection points are described. The monitoring network of this experiment has been designed in order to characterize the respective roles of the three karst conduits (west karst conduit, north karst conduit and Galerie des Poteries) leading to the main spring. The major results are following : (i) all the dye tracers have been identified at the Fontaine de Nimes spring (ii) the west karst conduit plays a major role in the drainage of the recharge area of the karst system (iii) no dye tracer has been identified on the north karst conduit (iv) the discharge rate into the Galerie des Poteries, measured by dilution of salt upstream injected, is less than 50 l/min, the recharge area of this conduit is geographically very limited. We can notice that well-structured breakthrough curves have been obtained for three of the four tracers.Le système karstique des garrigues nîmoises possède un exutoire principal, la Fontaine de Nîmes. Par le passé, plusieurs essais de traçages ont permis de mettre en évidence les relations entre des points supposés de son bassin d'alimentation et la Fontaine de Nîmes. Ces essais manquaient cependant de courbes de restitution. Dans cet article, les résultats d'un multi-traçage effectué en mars 2006 à partir de quatre points d'injection sont présentés. Le réseau de surveillance de cet essai a été conçu de façon à caractériser les rôles respectifs des différents conduits karstiques reconnus menant à la source principale. Les résultats majeurs sont les suivants : (i) tous les traceurs ont été identifiés à la Fontaine de Nîmes ; (ii) le conduit karstique ouest joue un rôle majeur dans le drainage du bassin d'alimentation de la Fontaine ; (iii) aucun traceur n'est identifié sur le conduit karstique nord, laissant présager un rôle mineur dans le drainage des parties ouest et nord du bassin d'alimentation ; (iv) un débit très faible, mesuré par dilution, transite dans la galerie des Poteries dont le bassin d'alimentation est géographiquement très limité. Par ailleurs, des courbes de restitution bien structurées ont été observées pour trois des quatre essais.Marechal Jean-Christophe, Courtois Nathalie, Jouanen Gilbert, Meus Philippe. Multi-traçage de la Fontaine de Nîmes. In: Karstologia : revue de karstologie et de spéléologie physique, n°56, 2e semestre 2010. Cavités glaciaires de l'Himalaya et L'écroulement du porche de la grotte Chauvet. pp. 1-8

Application de la courbe diagnostique aux essais de pompage en milieu karstique

Diagnostic plots applied to pumping tests in karst systems. Pumping tests conducted on wells intersecting karst heterogeneities such as the conduit network are difficult to interpret. Nevertheless, this case can be solved by assimilating the horizontal karst conduit to a finite-conductivity vertical fracture. In this case, several flow patterns corresponding to the respective contributions of karst subsystems (fractured matrix, small conduits, and main karst drainage network) can be identified on the diagnostic plot of the drawdown derivative. This is illustrated on two examples from Mediterranean karst systems in southern France. A pumping test on a well intersecting the main karst drainage network of the Cent-Fonts karst system shows (i) a preliminary contribution of the karst conduit storage capacity followed by (ii) linear flows into the fractured matrix. A pumping test on a well intersecting a small karst conduit of the Corbières karst system shows the existence of(i) bi-linear flow within both the karst conduit and the fractured matrix at early times, followed by (ii) radial flows within the fractured matrix and (Hi) finally the contribution of a major karst cavity. The use of diagnostic plots allows identifying the various flow regimes during pumping tests, corresponding to the response of the individual karst aquifer subsystems. This is helpful for improving the understanding of the structure of the karst aquifer and flow exchanges between subsystems.Les essais de pompage menés sur des puits traversant des hétérogénéités du karst telles que le réseau de drains sont difficiles à interpréter au moyen des techniques traditionnelles. Néanmoins, ce cas peut être abordé en assimilant le conduit karstique horizontal à une fracture verticale de perméabilité finie. Dans ce cas, plusieurs types d'écoulements correspondant aux contributions respectives des sous-systèmes du karst (matrice fracturée de la zone noyée, petits conduits, réseau de drainage principal) peuvent être identifiés sur la courbe diagnostique de la dérivée logarithmique du rabattement. Cette méthode est illustrée sur deux cas réels provenant d'aquifères karstiques méditerranéens du sud de la France. Un essai de pompage réalisé sur un puits traversant le réseau de drainage karstique principal du système des Cent-Fonts montre (1) une première contribution du stockage capacitif au sein du conduit karstique suivi (2) d'écoulements monodimensionnels au sein de la matrice fracturée. Un essai de pompage sur un puits traversant à grande profondeur un petit conduit karstique du système des Corbières montre l'existence (1) d'un écoulement bilinéaire au sein du conduit et de la matrice fracturée au début, suivi (2) d'écoulements radiaux au sein de la matrice fracturée et enfin (3) de la contribution d'une cavité karstique majeure. L'utilisation de la courbe diagnostique établie à l'aide de la dérivée des rabattements permet d'identifier les différents régimes d'écoulements durant un essai de pompage, correspondant aux réponses successives des sous-systèmes de l'aquifère karstique. Ceci contribue à mieux comprendre la structure de l'aquifère karstique ainsi que les échanges de flux entre sous-systèmes.Marechal Jean-Christophe, Ladouche Bernard, Dewandel Benoît, Fleury Perrine, Dörfliger Nathalie. Application de la courbe diagnostique aux essais de pompage en milieu karstique. In: Karstologia : revue de karstologie et de spéléologie physique, n°57, 1er semestre 2011. Spéléothèmes du Désert libyque (Egypte) et Fantômes de roche en Entre-deux-Mers (Gironde) pp. 33-36

Diastereoselective Synthesis of a Dyn[3]arene with Distinct Binding Behaviors toward Linear Biogenic Polyamines

International audienc

Normal volumetric and T1 relaxation time values at 1.5 T in segmented pediatric brain MRI using a MP2RAGE acquisition

Objectives This study introduced a tailored MP2RAGE-based brain acquisition for a comprehensive assessment of the normal maturing brain. Methods Seventy normal patients (35 girls and 35 boys) from 1 to 16 years of age were recruited within a prospective monocentric study conducted from a single University Hospital. Brain MRI examinations were performed at 1.5 T using a 20-channel head coil and an optimized 3D MP2RAGE sequence with a total acquisition time of 6:36 min. Automated 38 region segmentation was performed using the MorphoBox (template registration, bias field correction, brain extraction, and tissue classification) which underwent a major adaptation of three age-group T1-weighted templates. Volumetry and T1 relaxometry reference ranges were established using a logarithmic model and a modified Gompertz growth respectively. Results Detailed automated brain segmentation and T1 mapping were successful in all patients. Using these data, an age-dependent model of normal brain maturation with respect to changes in volume and T1 relaxometry was established. After an initial rapid increase until 24 months of life, the total intracranial volume was found to converge towards 1400 mL during adolescence. The expected volumes of white matter (WM) and cortical gray matter (GM) showed a similar trend with age. After an initial major decrease, T1 relaxation times were observed to decrease progressively in all brain structures. The T1 drop in the first year of life was more pronounced in WM (from 1000-1100 to 650-700 ms) than in GM structures. Conclusion The 3D MP2RAGE sequence allowed to establish brain volume and T1 relaxation time normative ranges in pediatrics

S100A2 is a predictive biomarker of adjuvant therapy benefit in pancreatic adenocarcinoma

Background Prognosis of patients with pancreatic adenocarcinoma (PAC) remains poor. S100A2 has been recently suggested as a negative prognostic biomarker in PAC. We aimed to investigate its prognostic and/or predictive value in a large independent multicentric cohort of patients with resected PAC. Methods Sequential samples of 471 patients were retrospectively collected; 142 patients did not receive adjuvant treatment (30%) and 329 (70%) received an adjuvant treatment. We measured protein levels of S100A2 by semiquantitative immunohistochemistry with tissue microarrays and correlated with patients' overall survival (OS) and disease-free survival (DFS). Results S100A2 protein status was obtained in 462 (98%) patients. Its expression was low, moderate or high in 59%, 12% and 2% of cases, respectively. It was not correlated with DFS or OS in the whole population, neither in the subgroup of patients who did not receive adjuvant treatment. However among patients who received an adjuvant therapy, moderate/high levels of S100A2 were significantly associated with longer OS and DFS in multivariate analysis (hazard ratios of 0.63, p = 0.022 and 0.67, p = 0.017, respectively), whereas low S100A2 was not. Interaction tests for adjuvant therapy were statistically significant both for the OS and the DFS (p = 0.001 and p = 0.023, respectively). On multivariate analysis, S100A2 retained independent predictive values (OS: p < 0.001, DFS: p = 0.003) with a significant benefit of adjuvant therapy for those patients with moderate/high S100A2. Conclusions S100A2 expression predicts longer DFS and OS in patients treated with adjuvant therapy and should be evaluated as a predictive biomarker. © 2013 Elsevier Ltd. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Levels of gemcitabine transport and metabolism proteins predict survival times of patients treated with gemcitabine for pancreatic adenocarcinoma.

Patients who undergo surgery for pancreatic ductal adenocarcinoma (PDAC) frequently receive adjuvant gemcitabine chemotherapy. Key determinants of gemcitabine cytotoxicity include the activities of the human equilibrative nucleoside transporter 1 (hENT1), deoxycytidine kinase (dCK), and ribonucleotide reductase subunit 1 (RRM1). We investigated whether tumor levels of these proteins were associated with efficacy of gemcitabine therapy following surgery.Journal ArticleMulticenter StudyResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe