Search

Your search keyword '"Le Breton, E."' showing total 128 results
Start Over Author "Le Breton, E."
128 results on '"Le Breton, E."'

2. Elizabethkingia anophelis outbreak in France

Author

Guerpillon, B., primary, Fangous, M.S., additional, Le Breton, E., additional, Artus, M., additional, le Gall, F., additional, Khatchatourian, L., additional, Talarmin, J.P., additional, Plesiat, P., additional, Jeannot, K., additional, Saidani, N., additional, and Rolland-Jacob, G., additional

Published
2022
Full Text
View/download PDF

3. Constraints on crustal structure in the vicinity of the Adriatic Indenter (European Alps) from Vp and Vp/Vs Local Earthquake Tomography

Author

Jozi Najafabadi, A., Haberland, C., Le Breton, E., Handy, M., Verwater, V., Heit, B., Weber, M., and the AlpArray and AlpArray SWATH-D Working Groups

Subjects
Geophysics, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous)
Abstract

In this study, 3-D models of P-wave velocity (Vp) and P- and S-wave ratio (Vp/Vs) of the crust and upper mantle in the Eastern and eastern Southern Alps (northern Italy and southern Austria) were calculated using local earthquake tomography (LET). The dataset includes high-quality arrival-times from well-constrained hypocenters observed by the dense, temporary seismic networks of the AlpArray AASN and SWATH-D. The resolution of the LET was checked by synthetic tests and analysis of the Model Resolution Matrix. The small inter-station spacing (average of ∼15 km within the SWATH-D network) allowed us to image crustal structure at unprecedented resolution across a key part of the Alps. The derived P velocity model revealed a highly heterogeneous crustal structure in the target area. One of the main findings is that the lower crust is thickened, forming a bulge at 30-50 km depth just south of and beneath the Periadriatic Fault and the Tauern Window. This indicates that the lower crust decoupled both from its mantle substratum as well as from its upper crust. The Moho, taken to be the iso-velocity contour of Vp=7.25 km/s, agrees with the Moho depth from previous studies in the European and Adriatic forelands. It is shallower on the Adriatic side than on the European side. This is interpreted to indicate that the European Plate subducted beneath the Adriatic Plate in the Eastern and eastern Southern Alps.

Published
2022

5. Accuracy of gradient diffusion method for susceptibility testing of dalbavancin and comparators

Author

Leroy, A. G., primary, Lavigne-Quilichini, V., additional, Le Turnier, P., additional, Loufti, B., additional, Le Breton, E., additional, Piau, C., additional, Kempf, M., additional, Pantel, A., additional, Amara, M., additional, Neuwirth, C., additional, Sanchez, R., additional, Guinard, J., additional, Huon, J. F., additional, Grégoire, M., additional, and Corvec, S., additional

Published
2021
Full Text
View/download PDF

10. Relocation of earthquakes in the Southern and Eastern Alps (Austria, Italy) recorded by the dense, temporary SWATH–D network using a Markov chain Monte Carlo inversion

Author

Jozi Najafabadi, A., Haberland, Christian, Ryberg, Trond, Verwater, V. F., Le Breton, E., Handy, M. R., Weber, Michael, Apoloner, Maria-Theresia, Aubert, Coralie, Besançon, Simon, Bés de Berc, Maxime, Bokelmann, Götz, Brunel, Didier, Capello, Marco, Čarman, Martina, Cavaliere, Adriano, Chéze, Jérôme, Chiarabba, Claudio, Clinton, John, Cougoulat, Glenn, C. Crawford, Wayne, Cristiano, Luigia, Czifra, Tibor, D’Alema, Ezio, Danesi, Stefania, Daniel, Romuald, Dannowski, Anke, Dasović, Iva, Deschamps, Anne, Dessa, Jean-Xavier, Doubre, Cécile, Egdorf, Sven, Fiket, Tomislav, Fischer, Kasper, Friederich, Wolfgang, Fuchs, Florian, Funke, Sigward, Giardini, Domenico, Govoni, Aladino, Gráczer, Zoltán, Gröschl, Gidera, Heimers, Stefan, Heit, Ben, Herak, Davorka, Herak, Marijan, Huber, Johann, Jarić, Dejan, Jedlička, Petr, Jia, Yan, Jund, Hélène, Kissling, Edi, Klingen, Stefan, Klotz, Bernhard, Kolínský, Petr, Kopp, Heidrun, Korn, Michael, Kotek, Josef, Kühne, Lothar, Kuk, Krešo, Lange, Dietrich, Loos, Jürgen, Lovati, Sara, Malengros, Deny, Margheriti, Lucia, Maron, Christophe, Martin, Xavier, Massa, Marco, Mazzarini, Francesco, Meier, Thomas, Métral, Laurent, Molinari, Irene, Moretti, Milena, Nardi, Anna, Pahor, Jurij, Paul, Anne, Péquegnat, Catherine, Petersen, Daniel, Pesaresi, Damiano, Piccinini, Davide, Piromallo, Claudia, Plenefisch, Thomas, Plomerová, Jaroslava, Pondrelli, Silvia, Prevolnik, Snježan, Racine, Roman, Régnier, Marc, Reiss, Miriam, Ritter, Joachim, Rümpker, Georg, Salimbeni, Simone, Santulin, Marco, Scherer, Werner, Schippkus, Sven, Schulte-Kortnack, Detlef, Šipka, Vesna, Solarino, Stefano, Spallarossa, Daniele, Spieker, Kathrin, Stipčević, Josip, Strollo, Angelo, Süle, Bálint, Szanyi, Gyöngyvér, Szűcs, Eszter, Thomas, Christine, Thorwart, Martin, Tilmann, Frederik, Ueding, Stefan, Vallocchia, Massimiliano, Vecsey, Luděk, Voigt, René, Wassermann, Joachim, Wéber, Zoltán, Weidle, Christian, Wesztergom, Viktor, Weyland, Gauthier, Wiemer, Stefan, Wolf, Felix Noah, Wolyniec, David, Zieke, Thomas, Živčić, Mladen, Žlebčíková, Helena, Abreu, Rafael, Allegretti, Ivo, and Al-Halbouni, Djamil

Subjects
010504 meteorology & atmospheric sciences, Stratigraphy, Inversion (geology), Soil Science, Inverse transform sampling, Fault (geology), Induced seismicity, 010502 geochemistry & geophysics, 01 natural sciences, relocation, Nappe, symbols.namesake, Geochemistry and Petrology, 500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften, earthquakes, 0105 earth and related environmental sciences, Earth-Surface Processes, QE1-996.5, geography, geography.geographical_feature_category, Alps, Paleontology, Geology, Crust, Markov chain Monte Carlo, QE640-699, Geophysics, Epicenter, symbols, Seismology
Abstract

In this study, we analyzed a large seismological dataset from temporary and permanent networks in the southern and eastern Alps to establish high-precision hypocenters and 1-D VP and VP/VS models. The waveform data of a subset of local earthquakes with magnitudes in the range of 1–4.2 ML were recorded by the dense, temporary SWATH-D network and selected stations of the AlpArray network between September 2017 and the end of 2018. The first arrival times of P and S waves of earthquakes are determined by a semi-automatic procedure. We applied a Markov chain Monte Carlo inversion method to simultaneously calculate robust hypocenters, a 1-D velocity model, and station corrections without prior assumptions, such as initial velocity models or earthquake locations. A further advantage of this method is the derivation of the model parameter uncertainties and noise levels of the data. The precision estimates of the localization procedure is checked by inverting a synthetic travel time dataset from a complex 3-D velocity model and by using the real stations and earthquakes geometry. The location accuracy is further investigated by a quarry blast test. The average uncertainties of the locations of the earthquakes are below 500 m in their epicenter and ∼ 1.7 km in depth. The earthquake distribution reveals seismicity in the upper crust (0–20 km), which is characterized by pronounced clusters along the Alpine frontal thrust, e.g., the Friuli-Venetia (FV) region, the Giudicarie–Lessini (GL) and Schio-Vicenza domains, the Austroalpine nappes, and the Inntal area. Some seismicity also occurs along the Periadriatic Fault. The general pattern of seismicity reflects head-on convergence of the Adriatic indenter with the Alpine orogenic crust. The seismicity in the FV and GL regions is deeper than the modeled frontal thrusts, which we interpret as indication for southward propagation of the southern Alpine deformation front (blind thrusts).

Published
2020

11. Accuracy of gradient diffusion method for susceptibility testing of dalbavancin and comparators.

Author

Leroy, A. G., Lavigne-Quilichini, V., Le Turnier, P., Loufti, B., Le Breton, E., Piau, C., Kempf, M., Pantel, A., Amara, M., Neuwirth, C., Sanchez, R., Guinard, J., Huon, J. F., Grégoire, M., and Corvec, S.

Abstract

This multicenter study aimed to assess the performances of gradient diffusion (GD) method in comparison to broth microdilution (BMD) method for susceptibility testing of dalbavancin, daptomycin, vancomycin, and teicoplanin. Minimum Inhibitory Concentrations (MICs) were retrospectively determined concomitantly by BMD and GD methods, for 93 staphylococci and enterococci isolated from clinical samples. BMD was considered as the gold standard. Essential (EA) and categorical agreements (CA) were calculated. Discordant categorical results were categorized as major (ME) and very major errors (VME). EA and CA were 95.7% and 96.8%, 82.8% and 100%, 97.8% and 96.8%, and 94.6% and 95.7% for dalbavancin, daptomycin, vancomycin, and teicoplanin respectively. Concerning dalbavancin, 3 ME without any VME were observed and discrepancies were low (≤ to 2 two-fold dilutions) between both methods. VME were noted in 1 and 3 cases for vancomycin and teicoplanin, respectively, and resulted from 1 two-fold dilution discrepancy in each case. EA was lower for daptomycin. When they were discrepant, BMD MICs were systematically higher than GD ones. Nevertheless, no categorical discrepancy was noted. GD appears as an acceptable and convenient alternative for dalbavancin, vancomycin, and teicoplanin MICs determination. Our study also emphasizes how achieving accurate daptomycin MICs remains challenging. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

12. Dynamique hydro-érosive actuelle des bassins versants endoréiques de la région de Niamey (sud-ouest du Niger)

Author

Bouzou Moussa, I., Malam Abdou, M., Ingata Warzagan, A., Boubacar Na-Allah, A., Bahari Ibrahim, M., Faran Maiga, O., Mamadou, I., Abba, B., Descroix, Luc, Le Breton, E., Vandervaere, J.P., Patrimoines locaux, Environnement et Globalisation (PALOC), and Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)

Subjects
geography, geography.geographical_feature_category, SAHEL, Forestry, 15. Life on land, Structural basin, NIGER, 6. Clean water, Watershed scale, Runoff coefficient, NIAMEY, Measurement device, 13. Climate action, Soil retrogression and degradation, Erosion, Environmental science, 14. Life underwater, Ravine, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, Surface runoff
Abstract

La generalisation du ravinement et la baisse de la productivite des terres sont quelques-unes des principales contraintes qui assaillent l’utilisation des sols au Sahel. Pour gerer efficacement ces sols, une evaluation des processus hydro-erosifs est necessaire. Ce travail a ainsi pour objectif d’analyser la dynamique hydro-erosive sur un site experimental installe depuis 2004 dans la region de Niamey (Niger). Sur ce site, le dispositif de mesure est compose de huit parcelles de mesures de ruissellement et d’erosion, des stations hydrometriques a l’exutoire des deux bassins versants endoreiques et de plusieurs piquets destines aux suivis morpho-dynamiques des ravines. Apres une decennie d’observation, les ruissellements mesures sur les parcelles se caracterisent par une dynamique saisonniere croissante sur les surfaces encroutees (croutes biologique et d’erosion) et decroissante sur les surfaces cultivees. Le coefficient de ruissellement varie de 5 % sur la surface cultivee a 58 % sur la croute d’erosion. Au cours des 10 annees de mesure, ce coefficient a connu une forte croissance en particulier sur la jachere (+ 80 %) et sur la surface cultivee (+ 300 %), traduisant ainsi la degradation des sols. A l’echelle des bassins versants, l’augmentation du coefficient de ruissellement s’accompagne d’une erosion areolaire qui decape le sol a une vitesse moyenne de 5 mm/an et d’une erosion lineaire active, de l’ordre de 4 m3/an au niveau des ravines suivies. Les transferts sedimentaires qui en resultent agissent sur le fonctionnement morpho-sedimentaire des cours d’eau. Des amenagements antierosifs sont necessaires pour dissiper les processus hydro-erosifs et preserver les services ecosystemiques des sols des bassins. Widespread gullying and the declining land productivity are some of the main constraints plaguing land use in the Sahel. In order to effectively manage these soils, it has become necessary to assess the hydro-erosive processes. The current study, thus, aims at analyzing the hydro-erosion dynamics on an experimental site installed since 2004 in the Niamey region (Niger Republic). On this site, the measurement device is made up of eight runoff and erosion measurement plots, hydrometric stations at the outlet of the two endorheic watersheds and several stakes intended for morpho-dynamic monitoring of the gullies. After a decade of observation, the runoff measured on the plots is characterized by an increasing seasonal dynamic on encrusted surfaces (biological and erosion crusts) and a decreasing one on cultivated surfaces. The runoff coefficient varies from 5% on the cultivated area to 58% on the erosion crust. Over the 10 years of measurement, this coefficient has greatly increased, especially on the fallow (+ 80%) and on cultivated area (+ 300%); this increase consequently reflects soil degradation. At the watershed scale, the increase in the runoff coefficient is accompanied by area erosion (or the erosion of the area out of the basin) which strikes the soil at an average speed of 5 mm/year and active linear erosion measuring 4 m3/year as observed at the monitored (the ongoing investigated) gullies. The resulting sediment transfers act on the morpho-sedimentary functioning of rivers. Anti-erosion facilities are necessary to dissipate the hydro-erosive processes and preserve the ecosystem services of the soil in the basins

Published
2020

13. Formation and Evolution of the Lower Magdalena Valley Basin and San Jacinto Fold Belt of Northwestern Colombia: Insights from Upper Cretaceous to Recent Tectono–Stratigraphy

Author

Mora–Bohórquez, J., Oncken, O., Le Breton, E., Ibañez–Mejia, M., Veloza, G., Mora, A., Vélez, V., and De Freitas, M.

Abstract

Using a regional geological and geophysical dataset, we reconstructed the stratigraphic evolution of the Lower Magdalena Valley Basin and San Jacinto fold belt of northwestern Colombia. Detailed interpretations of reflection seismic data and new geochronology analyses reveal that the basement of the Lower Magdalena Basin is the northward continuation of the basement terranes of the northern Central Cordillera and consists of Permian – Triassic metasedimentary rocks intruded by Upper Cretaceous granitoids. Structural analyses suggest that the NE–SW strike of faults in basement rocks underlying the northeastern Lower Magdalena is inherited from a Jurassic rifting event, while the ESE–WNW—striking faults in the western part originated from a Late Cretaceous to Eocene strike–slip and extensional episode. The Upper Cretaceous to lower Eocene sedimentary rocks preserved in the present–day San Jacinto fold belt were deposited in a submarine, forearc basin formed during the coeval oblique convergence between the Caribbean and South American Plates. A lower to middle Eocene angular unconformity at the top of the upper Paleocene to lower Eocene San Cayetano sequence, the termination of the activity of the Romeral Fault System, and the cessation of arc magmatism are all interpreted to indicate the onset of low–angle orthogonal subduction of the Caribbean Plateau beneath South America between 56 and 43 Ma. Flat subduction of the plateau has continued to the present and would be the main cause of amagmatic post–Eocene deposition and formation of the Lower Magdalena Valley Forearc Basin. Extensional reactivation of inherited, pre–Oligocene basement faults was crucial for the tectonic segmentation of the basin and the formation of its two depocenters (Plato and San Jorge). Late Oligocene to early Miocene fault–controlled subsidence allowed initial infill of the Lower Magdalena, while uplift of Andean terranes made possible the connection of the Lower and Middle Magdalena Valleys, and the formation of the largest Colombian drainage system (Magdalena River system). This drainage system started delivering enormous amounts of sediments in middle Miocene times, as fault–controlled subsidence was gradually replaced by sedimentary loading. Such dramatic increase in sedimentation and the huge volume of sediment being delivered to the trench caused the formation of forearc highs in San Jacinto and of an accretionary prism farther to the west. Our results highlight the fundamental role of plate kinematics, inherited basement structure and sediment flux on the evolution of forearc basins such as the Lower Magdalena and San Jacinto.

Published
2020

14. 3D lithospheric structure of the Caribbean and north South American Plates and Rotation Files of Kinematic Reconstructions back to 90 Ma of the Caribbean Large Igneous Plateau

Author

Gomez Garcia, A., Le Breton, E., Scheck-Wenderoth, M., Monsalve, G., and Anikiev, D.

Abstract

We are providing the geophysical data used to develop a gravity validated 3D lithospheric configuration of the Caribbean and north South American plates. The sources of these data are described in Section 4 of this README. Republication of subsets of these data are with permission of the authors or allowed by the licences of the input data. This data repository contains the lithospheric layers of the gravity validated 3D structural and density model of the Caribbean and north South American plates. In this model, the integration of different publicly available geophysical datasets was made, after an interpolation to a homogeneous spatial resolution of 25 km was performed. The data repository also contains the average density of the crystalline crust obtained after forward modelling the gravity anomalies. Additionally, the rotation files of the GPlates reconstructions of the Caribbean Large Igneous Plateau (CLIP) back to 90 Ma are included. This kinematic analysis was based on different reconstructions previously published by other authors. Further information and citations are given on the README file associated to this data repository.

Published
2020

15. Crustal Structure of the Southern and Eastern Alps using the Temporary SWATH-D Seismic Network

Author

Jozi Najafabadi, A., Haberland, C., Verwater, V., Handy, M., Le Breton, E., and Weber, M.

Abstract

The Alps formed during the African-European collision. Although the Alps are in the focus of geoscientific research over decades, its crustal and upper-mantle structure are still not completely known. The Periadriatic Lineament, a late orogonic fault active in Oligo-Miocene time, is sinistrally offset by the Guidicarie Fault. It is controversially discussed whether or not a switch in the subduction polarity on either side of the Guidicarie Fault can be observed. Our aim is to reveal the 3-D crustal structure of this section of the Alps at high-resolution by local earthquake tomography (LET). We use data of a temporary seismic network in the Southern and Eastern Alps (SWATH-D) which consists of 150 stations with an inter-station spacing of 15 km. The data from selected AlpArray (AASN) stations was included too. The first results of the inversion for hypocenters, velocity model, and station corrections are in a good agreement with the previous local and regional studies. However, our 1-D velocity model for this particular part of the Alps indicates upper-crustal velocities that are higher than the Alpine average. The seismicity pattern comprises diffuse clusters of earthquakes within the upper 25 km of the crust in the Friuli, Lake-Garda, Trentino and Brenner regions. The centre of the study region shows anomalously low seismic activity. This seismicity pattern indicates where ongoing Adria-Europe convergence is currently accommodated. A preliminary 3-D inversion shows satisfactory resolution and reveals the structure of the crust and uppermost mantle down to 50 km in most of the target area.

Published
2019

16. Linking Late Cretaceous to Eocene Tectono-stratigraphy of the San Jacinto fold belt of NW Colombia with Caribbean plateau collision and flat subduction

Author

Mora, A., Oncken, O., Le Breton, E., Ibánez-Mejia, M., Faccenna, C., Veloza, G., Vélez, V., de Freitas, M., Mesa, A., Mora, J. Alejandro, Oncken, Onno, Le Breton, Eline, Ibánez-Mejia, Mauricio, Faccenna, Claudio, Veloza, Gabriel, Vélez, Vickye, de Freitas, Mario, and Mesa, Andrés

Subjects
Caribbean, Lower Magdalena Valley, Geochemistry and Petrology, reflection seismic, flat subduction, Geophysic, San Jacinto fold belt, tectonostratigraphy
Abstract

Collision with and subduction of an oceanic plateau is a rare and transient process that usually leaves an indirect imprint only. Through a tectonostratigraphic analysis of pre-Oligocene sequences in the San Jacinto fold belt of northern Colombia, we show the Late Cretaceous to Eocene tectonic evolution of northwestern South America upon collision and ongoing subduction with the Caribbean Plate. We linked the deposition of four fore-arc basin sequences to specific collision/subduction stages and related their bounding unconformities to major tectonic episodes. The Upper Cretaceous Cansona sequence was deposited in a marine fore-arc setting in which the Caribbean Plate was being subducted beneath northwestern South America, producing contemporaneous magmatism in the present-day Lower Magdalena Valley basin. Coeval strike-slip faulting by the Romeral wrench fault system accommodated right-lateral displacement due to oblique convergence. In latest Cretaceous times, the Caribbean Plateau collided with South America marking a change to more terrestrially influenced marine environments characteristic of the upper Paleocene to lower Eocene San Cayetano sequence, also deposited in a fore-arc setting with an active volcanic arc. A lower to middle Eocene angular unconformity at the top of the San Cayetano sequence, the termination of the activity of the Romeral Fault System, and the cessation of arc magmatism are interpreted to indicate the onset of low-angle subduction of the thick and buoyant Caribbean Plateau beneath South America, which occurred between 56 and 43Â Ma. Flat subduction of the plateau has continued to the present and would be the main cause of amagmatic post-Eocene deposition.

Published
2017

21. Organische Mikroanalyse

Author

Rosenthaler, L., Nicloux, M., Le Breton, E., Dontcheff, A., Fromm, F., Liebermann, C., Häse, G., Fischer, Hans, Meyer-Betz, F., and Salkowski, E.

Published
1937
Full Text
View/download PDF

22. Mikronachweis und -bestimmung anorganischer Bestandteile im menschlichen und tierischen Organismus

Author

Lilpschitz, W., van Slyke, D. D., Erdös, J., Merejkovsky, B. K., Lavollay, J., Arnoux, M., Harger, R. N., Widmark, E. M. P., Fraenckel, P., Nicolai, H. W., Cantoni, O., Behre, J. A., Folin, O., Denis, W., Coquoin, R., Lupu, R., Arreguine, V., Garcia, E. D., Gorbach, G., Kadner, R., Halden, W., Jendrassik, L., Bokrétás, A., v. Wacek, A., Löffler, H., Klein, G., Steiner, M., Denigès, G., Rappaport, F., Geiger, G., Theorell, H., Widström, G., Cullen, G. E., Starlinger, W., Servantie, L., Demenier, G., Merklen, P., Le Breton, E., Adnot, A., van Zijp, C., Bruce, W. F., Doneen, L. D., Lehmann, O., Kerstan, G., Polster, H., and Warburg, O.

Published
1937
Full Text
View/download PDF

23. Les changements d’usage des sols et leurs conséquences hydrogéomorphologiques sur un bassin-versant endoréique sahélien

Author

Moussa, Ibrahim, Descroix, Luc, Laurent, J.-P., Vauclin, M., Amogu, Okechukwu, Boubkraoui, Stéphane, Ibrahim, B., Galle, Sylvie, Cappelaere, Bernard, Bousquet, S., Mamadou, I., Le Breton, E., Lebel, Thierry, Quantin, G., Ramier, D., Boulain, N., Centre d'Études et de Recherches sur le Développement International (CERDI), Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'étude des transferts en hydrologie et environnement (LTHE), Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Transpore, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Institut international d'ingénierie de l'eau et de l'environnement (2iE), Hydrosciences Montpellier (HSM), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), HYBIS, Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement - Direction Ile-de-France (Cerema Direction Ile-de-France), Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement (Cerema), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), 2iE, 2IE, Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Panthéon-Sorbonne (UP1), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), and Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Runoff, [SDU]Sciences of the Universe [physics], [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Endorheic area, Niger, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, Deep infiltration, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Sandy soil
Abstract

International audience; Despite the strong reduction in rainfall observed after 1968, the water table of some endorheic areas in the Sahel has been found to be rising over the last several decades. It has been previously demonstrated that this is due to land use changes which have led to a severe increase in runoff and erosion. In such areas, the excess in runoff causes a strong increase in the number of ponds, their sizes and thus, their duration. Ponds have been identified as the main zones of deep infiltration of water. The aim of this study was to investigate whether other areas of the Sahelian region could also be defined as deep infiltration ones as well, and then, whether they were contributing to aquifer recharge. Soil water content was surveyed for five consecutive years (2004-2008) by implementing a set of measurement devices at different depths. The hydrologic water balance was monitored at stream flow gauge stations located upstream and downstream of two small endorheic catchments. The observed replacement of bush vegetation by crops and fallow areas led to the appearance of extended bare soil areas due to both aeolian and hydric erosion, triggering a strong reduction in soil infiltrability under millet fields and fallow lands as well as in the soil water holding capacity. It also resulted in the formation of a great number of gullies and sand sediment deposits in the endorheic areas. Measurements showed that sandy deposits correspond in fact to large areas of deep infiltration: tens of thousands of cubic meters of water infiltrated catchments of less than 1 km(2). Runoff decreased by up to 50% in the sandy deposit areas, while infiltration (close to 1300 mm h(-1)) was observed up to depths of 10 m. These factors would raise the water table and significantly modify the surface and sub-surface components of the water cycle.

Published
2011

24. Runoff evolution according to land use change in a small Sahelian catchment

Author

Descroix, Luc, Esteves, Michel, Souley Yero, K., Rajot, Jean-Louis, Malam Abdou, M., Boubkraoui, S., Lapetite, Jean-Marc, Dessay, N., Zin, I., Amogu, O., Bachir, A., Moussa, I., Le Breton, E., Mamadou, I., Bouzou Moussa, I., HYBIS, Laboratoire d'étude des transferts en hydrologie et environnement (LTHE), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), RIVER, Biogéochimie et écologie des milieux continentaux (Bioemco), Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Paris (ENS Paris), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Departement de géographie, Université Abdou Moumouni [Niamey]-Université Abdou Moumouni [Niamey], UMR ESPACE/IRD, CHYC, Departement de géographie, Université Abdou Moumouni [Niamey], Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Panthéon-Sorbonne (UP1), Patrimoines Locaux et Gouvernance (PALOC), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD), Institut de gestion des entreprises -USJ (IGE), Université Saint-Joseph de Beyrouth (USJ), Institut d'écologie et des sciences de l'environnement de Paris (IEES (UMR_7618 / UMR_D_242 / UMR_A_1392 / UM_113) ), Institut National de la Recherche Agronomique (INRA)-Sorbonne Université (SU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Expertise et spatialisation des connaissances en environnement (ESPACE), Techniques of Informatics and Microelectronics for integrated systems Architecture (TIMA), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Institut d'écologie et des sciences de l'environnement de Paris (iEES Paris), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Departement de géographie, Techniques de l'Informatique et de la Microélectronique pour l'Architecture des systèmes intégrés (TIMA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Paris 1 Panthéon-Sorbonne (UP1), JEAI (Jeune Equipe Associee a l'IRD) 'SAPALOTE' (Long Term Savannah Park), ANR ECLIS French programme, ANR French programme ESCAPE-10-CEPL-005, European Community, ECCO-PNRH French National Hydrological Research Programme, Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), and Descroix, Luc

Subjects
010504 meteorology & atmospheric sciences, crusted soils, 0207 environmental engineering, Drainage basin, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 02 engineering and technology, changement d'usage des sols, 01 natural sciences, utilisation des terres, eau, Land use, land-use change and forestry, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, évolution, Water cycle, runoff coefficient, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, 020701 environmental engineering, duration of flow, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, coefficient d'écoulement, 0105 earth and related environmental sciences, Hydrology, geography, Topsoil, geography.geographical_feature_category, climat, Land use, Flood myth, afrique de l'ouest, sahel, 15. Life on land, bassin versant, 6. Clean water, Infiltration (hydrology), [SDU]Sciences of the Universe [physics], [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Environmental science, eau de ruissellement, Surface runoff, land-use changes, durée de l'écoulement
Abstract

Significant land use changes have been observed in West Africa, particularly in the Sahel region where climatic and demographic factors have led to a rise in cultivated areas, in recent decades. These changes caused strong modifications in the water cycle and in river regimes. By comparing the rainfall-runoff relationships for two periods (1991–1994 and 2004–2010) in two small neighbouring catchments (approx. 0.1 km2 each) of the Sahel, this study highlights the different hydrological consequences of land use change, particularly vegetation clearing and the consequent degradation of topsoil. Runoff increased in the upper basin, while it decreased in the lower basin, due to a strong increase in in-channel infiltration. Flood peak durations have become shorter in the downstream part of the catchment due to the huge increase of runoff water transmission losses within the gullies. Further study will consist of equipping one of the catchments with anti-erosion devices (mainly "half-moons" and terraces) in order to evaluate the influence of anti-erosion devices on runoff and suspended load.

Published
2011

25. Les changements d'usage des sols et leurs conséquences hydro-géomorphologiques sur un bassin versant endoréique sahélien

Author

Bouzou Moussa, I., Descroix, L., Faran Maiga, O., Emmanuèle Gautier, Moustapha Adamou, M., Esteves, M., Souley Yero, K., Malam Abdou, M., Mamadou, I., Le Breton, E., Abba, B., Université A. Moumouni, HYBIS, Laboratoire d'étude des transferts en hydrologie et environnement (LTHE), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Panthéon-Sorbonne (UP1), RIVER, Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Talour, Pascale, Université Abdou Moumouni [Niamey], Observatoire des Sciences de l'Univers de Grenoble (OSUG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)

Subjects
hydrogéologie, [SDU.STU.GM] Sciences of the Universe [physics]/Earth Sciences/Geomorphology, érosion hydrique, Sahel, Niger, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, état de surface des sols, occupation des sols, bassin-versant
Abstract

Les ressources naturelles des bassins-versants ruraux sahéliens subissent depuis plusieurs décennies une forte pression qui conduit à un changement radical de leur comportement hydro-géomorphologique. L'exemple est pris sur le bassin-versant du kori Dantiandou, bassin-versant endoréique de l'Ouest nigérien situé à environ 70 kilomètres à l'est de Niamey (Niger). Il s'agit plus particulièrement d'un de ses sous-bassins-versants, celui de Sama Dey (28,2 km 2 de superficie). Ce bassin-versant a connu de profondes mutations, avec entre autres, entre 1990 et 1999, une dégradation de la brousse tigrée sur les plateaux (- 4 %) et une diminution des jachères (- 3 %) sur les terres de culture des glacis. La diminution du couvert végétal entraîne la formation de surfaces encroÛtées (+ 12 %) génératrices de ruissellement et d'érosion sur des sols sableux éoliens très fragiles. Sur les parcelles, le coefficient de ruissellement annuel moyen par rapport aux pluies totales est de 50,4 % sur croÛte d'érosion, contre 2,8 % sur champ de mil avec des pertes en terres moyennes annuelles respectivement de 56,6 t/ha et 2 t/ha. Le coefficient d'écoulement annuel moyen est de 46 % à la station amont contre 26 % à la station aval. L'objectif de l'étude est de mettre en évidence le fonctionnement hydro-géomorphologique actuel avec comme facteur déterminant l'encroÛtement dÛ à la sensibilité des sols à la battance, phénomène lié aux changements d'usage des sols. L'approche méthodologique suivie a consisté à effectuer des observations et un suivi du ruissellement et de l'érosion sur de petites parcelles (2006-2008), à mesurer les débits liquides à deux stations de jaugeage à l'aide d'un moulinet (2004-2008) et à cartographier l'évolution de l'occupation des sols et des unités morphopédologiques. Comme résultats significatifs on peut retenir que les facteurs déclenchants du ruissellement et de l'érosion sur la période choisie sont, par ordre d'importance, les propriétés des sols, notamment leur sensibilité à la battance, l'occupation des sols, et la pente.

Published
2011

26. African monsoon multidisciplinary analyses : extended abstracts

Author

Moussa, B.B., Descroix, Luc, Boubkraoui, S., Mamadou, I., Alzouma, I., Le Breton, E., Amogu, O., Genau, I. (ed.), Marsh, S. (ed.), McQuaid, J. (ed.), Redelsperger, J.L. (ed.), Thorncroft, C. (ed.), and Van Den Akker, E. (ed.)

Subjects
EROSION, HYDROLOGIE, BILAN HYDRIQUE, UTILISATION DU SOL, RUISSELLEMENT, DEBIT, IMPACT SUR L'ENVIRONNEMENT
Published
2006

30. Runoff evolution according to land use change in a small Sahelian catchment

Author

Descroix, L., primary, Esteves, M., additional, Souley Yéro, K., additional, Rajot, J.-L., additional, Malam Abdou, M., additional, Boubkraoui, S., additional, Lapetite, J. M., additional, Dessay, N., additional, Zin, I., additional, Amogu, O., additional, Bachir, A., additional, Bouzou Moussa, I., additional, Le Breton, E., additional, and Mamadou, I., additional

Published
2011
Full Text
View/download PDF

48. The Effect of Coded Healing Abutments on Treatment Duration and Clinical Outcome: A Randomized Controlled Clinical Trial Comparing Encode and Conventional Impression Protocols.

Author

Abduo J, Chen C, Le Breton E, Radu A, Szeto J, Judge R, and Darby I

Abstract

Purpose: To compare the Encode impression protocol (Biomet 3i) with the conventional impression protocol in terms of treatment duration, clinical accuracy, and outcome up to the first postplacement review of single-implant crowns., Materials and Methods: A total of 45 implants were included in this study. The implants were randomly allocated to the Encode group (23 implants) or the conventional group (22 implants). At the time of surgery, all implants received two-piece Encode healing abutments. The implants were restored 3 months after insertion. In the conventional protocol, open-tray implant-level impressions were taken and the implants were restored with prefabricated abutments and porcelain-fused-to-metal (PFM) crowns. For the implants in the Encode group, closed-tray impressions of the healing abutments were taken. The generated casts were sent to the Biomet 3i scanning/milling center for custom abutment manufacturing on which PFM crowns were fabricated. Treatment duration (laboratory and clinical), clinical accuracy of occlusal and proximal contacts, and outcome (esthetics, patient satisfaction, and crown contour) were evaluated with the aid of a series of questionnaires., Results: The Encode protocol required significantly less laboratory time (18 minutes) than the conventional protocol for adjustment of the abutments. The impression pour time, time for the laboratory to return the crown, time for crown insertion at the final appointment, and total clinical time for crown insertion did not differ significantly between the two protocols. Likewise, clinical accuracy, esthetics, and patient satisfaction were similar for the two protocols., Conclusion: The two protocols were clinically comparable. The Encode protocol is advantageous in reducing the laboratory time before crown fabrication.

Published
2017
Full Text
View/download PDF

49. Secondary structure determination of 15N-labelled human Long-[Arg-3]-insulin-like growth factor 1 by multidimensional NMR spectroscopy.

Author

Laajoki LG, Le Breton E, Shooter GK, Wallace JC, Francis GL, Carver JA, and Keniry MA

Subjects
Amino Acid Sequence, Humans, Insulin-Like Growth Factor I chemistry, Molecular Sequence Data, Protein Folding, Insulin-Like Growth Factor I analogs & derivatives, Nuclear Magnetic Resonance, Biomolecular methods, Protein Structure, Secondary
Abstract

Insulin-like growth factors (IGFs) are a group of proteins that promote cell growth and differentiation. Long-[Arg-3]-IGF-I (Francis et al. (1992) J. Mol. Endocrinol. 8, 213-223), a potent analogue of IGF-I, which has a Glu-3 to Arg-3 substitution and a hydrophobic, thirteen amino acid N-terminal extension, has been studied by 1H,15N NMR spectroscopy. All the backbone 1H and 15N assignments and most of the 1H sidechain assignments have been completed. The secondary structure elements were identified by determining the sequential and medium range NOEs from sensitivity-enhanced 15N-NOESY-HSQC and sensitivity-enhanced 15N-HSQC-NOESY-HSQC spectra. The IGF-I domain of Long-[Arg-3]-IGF-I was found to have an almost identical structure to IGF-I. The N-terminal seven amino acid residues of the extension have very few medium range or long range NOEs but the next five amino acids form a turn-like structure that is spatially close to the beginning of helix 1 in the IGF-I domain. Hydrogen-deuterium exchange experiments show that all the slowly exchanging backbone amide protons in the IGF-I domain are either in the helical or the extended structural elements. Many of the amide protons in the N-terminal extension are also protected from the solvent although the residues in this part of the extension do not have any identifiable secondary structure. The results are interpreted in terms of the increased biological potency of Long-[Arg-3]-IGF-I and the decreased binding to insulin-like growth factor binding proteins.

Published
1997
Full Text
View/download PDF

50. Solution conformation of bovine lens alpha- and betaB2-crystallin terminal extensions.

Author

Le Breton ER and Carver JA

Subjects
Animals, Cattle, Magnetic Resonance Spectroscopy, Protein Conformation, Protons, Solutions, Crystallins chemistry, Peptide Fragments chemistry
Abstract

alpha- and betaB2-Crystallin are the major proteins in the mammalian lens. Each of these crystallins has short, flexible terminal extensions from its domain core; the two alpha-crystallin subunits have C-terminal extensions of eight and ten amino acids whilst betaB2-crystallin has N- and C-terminal extensions of 15 and 11 amino acids, respectively. The solution conformations of these chemically synthesised extensions have been examined by two-dimensional 1H NMR spectroscopy. The N-terminal extension of betaB2-crystallin and the C-terminal extensions of alpha-crystallin adopt little ordered structure. In the membrane-mimicking solvent trifluoroethanol, the alpha-crystallin extensions are also unstructured. In contrast, the C-terminal extension of betaB2-crystallin in water has a structural preference towards turn-like structures, creating a hydrophobic region involving G198, F200 and P202. In the lens, the C-terminal extension of betaB2-crystallin is the only one of these extensions that interacts to any large extent with other crystallins. The structural preference of the C-terminal extension of betaB2-crystallin may therefore have implications for the role of this extension in crystallin-crystallin interactions.

Published
1996
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results