Éditeur(s) : HAL CCSD Landes Bioscience
Résumé : International audience
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
Autophagy

hal-00735751
https://hal.archives-ouvertes.fr/hal-00735751
PUBMED : 22966490

Éditeur(s) : HAL CCSD
Résumé : International audience
The corrosion rates in the presence of some indole derivates, namely, 9H-pyrido[3,4-b]indole (norharmane) and 1-methyl-9H-pyrido[3,4-b]indole (harmane), as inhibitors of C38 steel corrosion inhibitor in 1 M HCl solution, were measured by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques, in the range of temperatures from 25 to 55∘C. Results obtained revealed that the organic compounds investigated have inhibiting properties for all temperatures. The inhibition was assumed to occur via adsorption of the indole molecules on the metal surface. Adsorption of indole derivates was found to follow the Langmuir isotherm. The apparent activation energies, enthalpies, and entropies of the dissolution process and the free energies and enthalpies for the adsorption process were determined by potentiodynamic polarization and electrochemical impedance. The fundamental thermodynamic functions were used to collect important information about indole inhibitory behaviour.
international Journal of Corrosion

hal-01683120
https://hal.univ-antilles.fr/hal-01683120
DOI : 10.1155/2013/139798

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The kinetics of hydrogenation of dry iron-bearing olivine single crystals was determined by performing hydration experiments under hydrothermal conditions at high pressure. The experiments were performed in a multi-anvil press at 3 GPa, for a temperature range between 900 and 1200 °C and for various durations. The oxygen fugacity was buffered along Ni-NiO joint. Polarized Fourier transform infrared spectroscopy and recent empirical calibration were used to quantify the hydroxyl distributions in the samples along crystallographic axes after the experiments. The chemical diffusion coefficients are similar (barely slower) than in olivine hydrated at lower pressure (0.2 and 0.3 GPa) for the same diffusion mechanism. Under the given experimental conditions, the anisotropy of diffusion is the same as for proton-vacancy mechanism, with diffusion along the [0 0 1] axis faster than along the [1 0 0]. However, the anisotropy at 3 GPa is weaker compared to measurements at lower pressures and the analysis of concentration profiles using 3D models shows that an isotropic solution could also be relevant. Fits of the diffusion data to an Arrhenius law yield activation energies for the slightly faster [0 0 1] axis of the crystallographic axes around 198 ± 5 kJ mol−1, a value only slightly lower than the results from previous experimental studies for natural iron-bearing olivine hydrogenated at lower confining pressure. At 3 GPa, hydrogenation can be well approximated by a single mechanism controlled by coupled diffusion of protons and octahedral vacancies (di- and tri-valent ions). The diffusion rates are fast enough to alter hydrogen concentration within olivine in xenoliths ascending from the mantle or experiencing hydrogen-rich metasomatism events, but too slow to permit complete homogenization of hydrogen in olivine-rich rocks at kilometer scale in less than one My.
ISSN: 0031-9201

hal-01412663
https://hal.archives-ouvertes.fr/hal-01412663
DOI : 10.1016/j.pepi.2016.08.005

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
Human leishmaniasis are widely spread diseases with different clinical forms caused by about 20 species within the Leishmania genus. Leishmania species identification is relevant for therapeutic management and prognosis, especially for cutaneous and muco-cutaneous forms. Several methods are available to identify Leishmania species from culture, but they have not been standardized for the majority of the currently described species, with the exception of MultiLocus Enzyme Electrophoresis. Moreover, these techniques are expensive, time-consuming and not available in all laboratories. Within the last decade, mass spectrometry (MS) has been adapted for microorganism identification, including Leishmania However, no commercial reference mass spectral database is available. In this study, a reference mass spectral library (MSL) for Leishmania isolates, accessible through a free web-based application (mass spectral identification, MSI), was constructed and tested. It includes mass spectral data for 33 different Leishmania species, including species that infect humans, animals and phlebotomine vectors. Four laboratories on two continents evaluated MSI performance using 268 samples of which 231 were Leishmania strains. All Leishmania strains, but one, were correctly identified at least at the complex level. A risk of species misidentification within the L. donovani, L. guyanensis and L. braziliensis complexes was observed, as already reported with other techniques. The tested application was reliable, with identification results comparable to those obtained with reference methods, but with a more favorable cost-efficiency ratio. This free online identification system relies on a scalable database and can be implemented directly in the user's computers.
ISSN: 0095-1137

hal-01571305
https://hal.archives-ouvertes.fr/hal-01571305
DOI : 10.1128/JCM.00845-17
PUBMED : 28724559

Éditeur(s) : HAL CCSD Royal Society of Chemistry
Résumé : International audience
A versatile sol-gel route has been developed for the preparation of hierarchical porous silica membrane material with highly dispersed platinum nanoparticles (Pt-NPs). The outstanding feature of the "one pot" synthesis developed in this work lies in the successful preparation of a stable complex suspension made of silica sol, multi-scale porogens and Pt nanoparticles. The multi-scale porogens were based on non-ionic triblock copolymers and aqueous latex suspension to create mesopores and macropores, respectively, with finely tuned pore size and organization. For further functionalization of the membranes, Pt nanoparticles of about 4 nm in diameter were prepared by irradiating with microwaves (MW) the Pt precursors added in the starting suspension. This original path is suggested to enable a pre-organization of Pt nanoparticles in the ordered mesoporous structure. The suspensions were then deposited as thin films on either dense or macroporous supports, and further thermally treated at 450°C to remove the porogen units. Hierarchical porous layers composed of micropores (<2 nm), ordered mesopores (∼4 nm) and macropores (∼70 nm) with or without Pt were prepared and characterized. The resulting membranes are foreseen to exhibit great potential as multifunctional membranes for gas separation coupled with catalytic reaction. © The Royal Society of Chemistry 2008.
ISSN: 0959-9428

hal-01680586
https://hal.univ-antilles.fr/hal-01680586
DOI : 10.1039/b807029f

Éditeur(s) : HAL CCSD EDP Sciences
Résumé : International audience
This paper presents a paleo-hydrological study conducted on sediment flood deposits at two sites located in the Gardon Gorges, Southeast France. The first study site is a valley‑side terrace (referred to as site GE, located 10m above the channel bed) and the second is located in a cave (referred to as site GG, perched 15m above the bed level). Paleo‑flood events were identified by carefully analyzing each slackwater flood deposits. The flood units were then dated using a variety of dating techniques, namely 137Cs, 210Pbex, 14C geochemical analysis of mining‑contaminated slackwater flood sediments, archeological objects and the historic flood record. Hydraulic modeling was also carried out in order to verify the coherence between the stratigraphic records of flood deposits at the sites and the historic flood levels known along the river Gardon. It is demonstrated that all the major flood events of the 20th century can be identified at terrace GE. This type of geomorphological unit can therefore be used as a sound basis for a paleo-hydrological analysis of the Gardon Gorges. Furthermore, the analysis of the stratigraphic record at site GG demonstrates that the site can be used to trace the largest flood events that have occurred within the past 600 years. The study reveals that the frequency of extreme flood events increased during the Little Ice Age
Une étude paléo-hydrologique a été entreprise dans les Gorges du Gardon, où deux coupes sédimentaires ont été étudiées. La première provient d'une terrasse (coupe GE située à 10 m de hauteur au dessus de la rivière) et l'autre, d'une cavité (coupe GG localisée à 15 m au-dessus de la rivière). L'identification et la mise en évidence des différents paléo-événements de crue ont été établies grâce à l'inspection minutieuse de chaque dépôt sédimentaire et d'une étude géochronologique fine (137Cs, 210Pbex, 14C, métaux traces, objets archéologiques, historiques des crues). Nous avons souhaité évaluer la capacité des terrasses fluviatiles du Gardon à enregistrer des paléo-événements en comparant les coupes sédimentaires aux données historiques des hauteurs d'eau et aux résultats d'un modèle hydraulique 1D. Nous montrons que la terrasse GE enregistre la quasi-totalité des évènements du 20ème siècle et qu'à priori, ce type d'objet géomorphologique peut être utilisé pour toute étude paléo-hydrologique sur le Gardon. De plus, l'étude de la coupe GG (cavité perchée à 15 m) permet de reconstituer les évènements intenses au cours des 600 dernières années. Nous montrons une augmentation des crues extrêmes dans le Haut-Languedoc au cours du "Petit âge glaciaire".
ISSN: 0018-6368

hal-01108400
https://hal.archives-ouvertes.fr/hal-01108400
https://hal.archives-ouvertes.fr/hal-01108400/document
https://hal.archives-ouvertes.fr/hal-01108400/file/ly2014-pub00041935.pdf
DOI : 10.1051/lhb/2014037

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Here we show that copper substitution in perovskite-type barium strontium cobalt copper oxide (BSCC) membranes confers extremely high oxygen fluxes well beyond the state of art, reaching 27.5 ml cm−2 min−1at 950 °C. A key feature of BSCC is the formation of a mixed matrix catalyst-perovskite membrane caused by the segregation of copper, leading to the formation of an intergranular network of copper-rich oxide between perovskite grains. BSCC membranes delivered pressure normalised oxygen flux (i.e. permeance) of up to 86 times higher, above pressure difference of 18 kPa, as compared to best perovskite membrane, BBSC, due to the catalytic effect of segregated copper oxide. Unlike conventional dual-phase membranes which contain ion and electron conducting phases, this work shows for the first time perovskite-type membranes consisting of a mixed matrix of oxygen ion/electron conducting (perovskite) and catalytic (copper oxide) phases, thus paving the way to the development of high performance membranes for oxygen separation from air for clean energy applications. © 2016 Elsevier B.V.
ISSN: 0376-7388

hal-01683219
https://hal.univ-antilles.fr/hal-01683219
DOI : 10.1016/j.memsci.2016.12.035

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
ISSN: 0927-7757

hal-00360369
https://hal.archives-ouvertes.fr/hal-00360369
DOI : 10.1016/j.colsurfa.2008.07.054

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We investigated the deformation mechanisms and the seismic properties of 10 eclogite samples from different localities (Alps, Norway, Mali and eastern China) through the analysis of their microstructures and lattice-preferred orientations (LPO). These samples are representative of various types and intensity of deformation under eclogitic metamorphic conditions. Omphacite and garnet LPO were determined from electron backscatter diffraction (EBSD) technique. Garnet appears to be almost randomly oriented whereas omphacite develops strong LPO, characterized by the [001]-axes concentrated sub-parallel to the lineation, and the (010)-poles concentrated sub-perpendicular to the foliation. In order to analyze the deformation mechanisms that produced such omphacite LPO, we compare our observations to LPO simulated by viscoplastic self-consistent numerical models. A good fit to the measured LPO is obtained for models in which the dominant slip systems are 1/2h110i{11 ¯ 0}, [001] {110} and [001] (100). Dominant activation of these slip systems is in agreement with TEM studies of naturally deformed omphacite. Seismic properties of eclogite are calculated by combining the measured LPO and the single crystal elastic constants of omphacite and garnet. Although eclogite seismic anisotropies are very weak (less than 3% for both P-and S-wave), they are generally characterized by a maximum P-wave velocity sub-parallel to the lineation and by a minimum velocity approximately normal to foliation. The mean P-and S-wave velocities are high (respectively, 8.6 and 4.9 km/s). The S-wave anisotropy pattern displays complex relationships with the structural frame but the fast polarization plane generally tends to be parallel to the foliation. Calculated reflection coefficients show that an eclogite/crust interface is generally a good reflector (Rc > 0.1), whereas an eclogite body embedded in the upper mantle would be hardly detectable.
ISSN: 0040-1951

hal-01389715
http://hal.univ-reunion.fr/hal-01389715
http://hal.univ-reunion.fr/hal-01389715/document
http://hal.univ-reunion.fr/hal-01389715/file/Bascou_eclo-sismo_tphy2001_hal.pdf
DOI : 10.1016/S0040-1951(01)00156-1

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Understanding the factors underlying the spatio-temporal distribution of infectious diseases provides useful information regarding their prevention and control. Dengue fever spatio-temporal patterns result from complex interactions between the virus, the host, and the vector. These interactions can be influenced by environmental conditions. Our objectives were to analyse dengue fever spatial distribution over New Caledonia during epidemic years, to identify some of the main underlying factors, and to predict the spatial evolution of dengue fever under changing climatic conditions, at the 2100 horizon. We used principal component analysis and support vector machines to analyse and model the influence of climate and socio-economic variables on the mean spatial distribution of 24,272 dengue cases reported from 1995 to 2012 in thirty-three communes of New Caledonia. We then modelled and estimated the future evolution of dengue incidence rates using a regional downscaling of future climate projections. The spatial distribution of dengue fever cases is highly heterogeneous. The variables most associated with this observed heterogeneity are the mean temperature, the mean number of people per premise, and the mean percentage of unemployed people, a variable highly correlated with people's way of life. Rainfall does not seem to play an important role in the spatial distribution of dengue cases during epidemics. By the end of the 21st century, if temperature increases by approximately 3°C, mean incidence rates during epidemics could double. In New Caledonia, a subtropical insular environment, both temperature and socio-economic conditions are influencing the spatial spread of dengue fever. Extension of this study to other countries worldwide should improve the knowledge about climate influence on dengue burden and about the complex interplay between different factors. This study presents a methodology that can be used as a step by step guide to model dengue spatial heterogeneity in other countries.
ISSN: 1935-2727

Droits : http://creativecommons.org/licenses/by/
pasteur-01247037
https://hal-riip.archives-ouvertes.fr/pasteur-01247037
https://hal-riip.archives-ouvertes.fr/pasteur-01247037/document
https://hal-riip.archives-ouvertes.fr/pasteur-01247037/file/journal.pntd.0004211.pdf
DOI : 10.1371/journal.pntd.0004211

Éditeur(s) : HAL CCSD
Résumé : International audience
Conférence MISTRALS PAELOMEX
Montpellier, France

hal-01683548
https://hal-univ-tlse2.archives-ouvertes.fr/hal-01683548

Éditeur(s) : HAL CCSD
Résumé : International audience
Treatment failure and symptomatic relapse are major concerns in American tegumentary leishmaniasis (ATL). Such complications are seen frequently in L.guyanensis infections where patients respond variously to first-line anti-leishmanials and are more prone to develop chronic cutaneous leishmaniasis. The factors underlying this pathology, however, are unknown. Recently ,: we reported that a dsRNA virus (LRV1) nested within L.guyanensis parasites is able to exacerbate experimental murine leishmaniasis by inducing a hyper-inflammatory response. This report investigates the prevalence of LRV1 in human L.guyanensis infection and its effect on treatment efficacy as well as its correlation to symptomatic relapses after the first-line treatment. In our cohort of 75 patients diagnosed with primary-localised ATL, the prevalence of LRV1+ infection was elevated to 58%. All patients infected with LRV1-negative L.guyanensis were cured after one (22/31 i.e.71%) or two (31/31 i.e.100%) doses of pentamidine. Oppositely, 12 out of the 44 LRV1-positive patients presented with persistent infection and symptomatic relapse required extended therapy and the use of second-line drugs. Finally, LRV1 presence was associated with a significant increase in intra-lesional inflammatory markers. In conclusion, LRV1 status in L.guyanensis infection is significantly predictive (p=0.0009) of first-line treatment failure and symptomatic relapse, and could stand to guide therapeutic choices in ATL
Journal of Infectious Diseases

hal-01175528
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01175528
DOI : 10.1093/infdis/jiv355
PUBMED : 26123564

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
In order to progress in the understanding of mechanical stress generation, the mesoporosity of the cell wall and its changes during maturation of poplar (Populus deltoides x P. nigra) tension wood (TW) and opposite wood (OW) were measured by nitrogen adsorption–desorption. Variations in the thickness of the gelatinous layer (G-layer) were also measured to clarify whether the mesoporosity change simultaneously with the deposition of the G-layer in TW. Results show that mesoporous structures of TW and OW were very similar in early development stages before the deposition of G-layers. With the formation of the S2 layer in OW and the G-layer in TW, the mesopore volume decreased steeply before lignification. However, in TW only, the decrease in mesopore volume occurred together with the pore shape change and a progressive increase in pore size. The different patterns observed in TW revealed that pores from G-layers appear with a different shape compared to those of the compound middle lamella, and their size increases duringthe maturation process until stabilising in mature wood. This observation strongly supports the hypothesis of the swelling of the G-layer matrix during maturation as the origin of maturation stress in poplar tension wood.
ISSN: 0028-646X

hal-01081834
https://hal.archives-ouvertes.fr/hal-01081834
https://hal.archives-ouvertes.fr/hal-01081834/document
https://hal.archives-ouvertes.fr/hal-01081834/file/Chang_al_Mesoporosity_changes_New-Phyto._2015.pdf
DOI : 10.1111/nph.13126

Éditeur(s) : HAL CCSD American Geophysical Union (AGU)
Résumé : International audience
We studied the patterns, rates and evolution of fluvial terraces and fault system during the building process of an intracontinental transpressional mountain in the Gobi-Altay (Mongolia). By analyzing incisions and offsets of fluvial terraces and alluvial fans, we show that the massif has grown by outward migration of thrust faults through time. On the northern flank, the present bounding thrust fault began its activity ~600 ka ago, while a more internal sub-parallel fault was still active until ~200-100 ka. Vertical offset of an alluvial fan abandoned ~100 ka ago allows an estimate of 0.1 mm/yr Upper Pleistocene - Holocene uplift rate. The morphology of the catchment-piedmont system strongly suggests a periodical formation of the alluvial surfaces, controlled by the climatic pulses, at the beginning of the wet interglacial periods. The abandonment of the alluvial terraces lags by several thousand years the abandonment of the alluvial fans, showing a diachronous incision propagating upstream. The incision rate deduced from the different elevations of straths exceeds of one order of magnitude the rock uplift rate. This excess is mostly due to ongoing drainage network growth at the core of the massif, and incision due to alluvial apron entrenchment near the outlet. This implies that fluvial response is mainly controlled by drainage growth, interaction with piedmont and cyclic climatic variations, rather than by rock uplift.
ISSN: 0278-7407

hal-00323558
https://hal.archives-ouvertes.fr/hal-00323558
https://hal.archives-ouvertes.fr/hal-00323558v2/document
https://hal.archives-ouvertes.fr/hal-00323558/file/Vassallo2007.pdf
DOI : 10.1029/2006TC002081

Éditeur(s) : HAL CCSD
Résumé : International audience
In the analysis of coastal hazards, the features of extreme waves are determining information to question the impact of storms to the coast. The spatial behaviour of extreme waves is even more valuable especially since it is sparsely provided. Regarding recent applications in other contexts, a kind of statistical models called max-stable processes is relevant for modelling spatial extreme events. Max-stable processes are extensions of the well-known Generalised Extreme Value (GEV) distribution. Unlike univariate approaches, max-stable processes consider spatial dependence of a phenomenon. Such a modelling also overtakes a standard multivariate approach by providing information continuously over the area studied, even where no observation is available. Relying on such a stochastic modelling, the aim of this study is to discuss the extreme waves hazards in the Gulf of Lions, focusing on their spatial behaviour.
34th Conference on Coastal Engineering
Seoul, South Korea

lirmm-01382568
https://hal-lirmm.ccsd.cnrs.fr/lirmm-01382568
https://hal-lirmm.ccsd.cnrs.fr/lirmm-01382568/document
https://hal-lirmm.ccsd.cnrs.fr/lirmm-01382568/file/7553-31212-1-PB.pdf
DOI : 10.9753/icce.v34.management.17

Éditeur(s) : HAL CCSD Elsevier
Résumé : Grain-size analyses, coupled with end-member modelling, have been performed on the terrigenous fraction of two Leg 184 Ocean Drilling Program sites (1144 and 1146) from the South China Sea. The grain-size distributions over the last 1.8 Ma enable a new interpretation of their connections to sea-level variations and East Asian monsoon strength. Previous investigations in this area have associated grain-size variability with enhanced eolian input during glacial stages. End-member modelling downgrades the importance of this eolian contribution and indicates that the sediments can be described as a mixture of three end-members: fluvial mud inputs, shelf reworking and river mouth migration. Grain-size variations in the Pleistocene section of the cores indicate a multiple-stage evolution: (i) from 1.8 to 1.25 Ma, the downcore grain-size variations are low but show a correspondence between monsoon rainfall intensity and the fine grain-sized fluvial inputs; no link with sea-level variations is noticeable; (ii) from 1.25 to 0.9 Ma, there is an increase (decrease) in the intermediate (fine) end-member (not, vert, similar 100 kyr cycle) that is associated with the onset of a stronger summer monsoon and modest shelf reworking; (iii) from 0.9 to 0 Ma the grain-size record is dominated by global sea-level variations; each glacial stage is associated with extensive shelf reworking and conveyance of coarse particles to the basin.
ISSN: 0033-5894

hal-00404671
https://hal.archives-ouvertes.fr/hal-00404671
DOI : 10.1016/j.yqres.2007.03.004

Éditeur(s) : HAL CCSD Centers for Disease Control and Prevention
Résumé : International audience
To determine when risk for Buruli ulcer is highest, we examined seasonal patterns in a highly disease-endemic area of Cameroon during 2002-2012. Cases peaked in March, suggesting that risk is highest during the high rainy season. During and after this season, populations should increase protective behaviors, and case detection efforts should be intensified.
ISSN: 1080-6040

Droits : http://creativecommons.org/licenses/by-nc-nd/
hal-01307147
https://hal-amu.archives-ouvertes.fr/hal-01307147
https://hal-amu.archives-ouvertes.fr/hal-01307147/document
https://hal-amu.archives-ouvertes.fr/hal-01307147/file/14-1336.pdf
DOI : 10.3201/eid2108.141336

Éditeur(s) : HAL CCSD
Résumé : Iran covers a large area limited in longitude by the meridians 44°E and 64°E and in latitude by the parallels 25°N and 40°N. Mapping a new gravity field over Iran is the first important data for geodetic, geophysicaland geodynamical considerations. In this thesis, the gravity measurements are used to determine the gravimetric geoid over Iran. This geoid is coupled with the GPS height and altitude (levelling) to realize an operational vertical surface at the territory of Iran. The contribution of the principal geodetic and gravimetric works realized in recent years are the establishment of: 1) the national absolute gravity network of Iran (NAGNI09), 2) the national gravity calibration line of Iran (NGCLI10) and 3) the multi-observations geodetic and gravimetric network of Iran (MPGGNI10). The absolute gravity network consists in 24 stations where the gravity measurement has been realized with the help of gravimeters FG5, with a precision better than 5μ Gal. The repetition of the observations at two stations between 2000 and 2007 makes obvious the inter-annual variations of gravity in relation of the amount of underground water changes and (or) tectonic deformation. The absolute gravity network has served the base stations for the realization of the MPGGNI10 geodetic and gravimetric network with a mesh of 55 km, at which the gravity is measured with the help of relative gravimeters CG-5 and CG-3/M, the GPS height and the altitude with a precision of 0.010 mGal, 0.03 m, and 3mm km respectively. The remove-restore technique coupled with the Helmert's condensation method is chousen to compute a new gravimetric geoid model, IRGeoid10, with a absolute and relative precision of the order of 0.26 m and 2.8 ppm respectively. The gravimetric geoid is adjusted at the GPS/levelling points to define new vertical reference surface over Iran
L'Iran couvre une grande superficie en longitude entre les méridiens 44°E et 64°E et en latitude entre les parallèles 25°N et 40°N. la cartographie de champ de pesanteur sur l'Iran est de premiére importance pour des considérations d'ordre géodésique, géophysique et geodynamique. Dans cette thèse, les mesures de pesanteur sont utilisées pour déterminer le géoïde gravimétrique sur l'Iran. Ce géoïde est couplé à la mesure de hauteur GPS et d'altitude (nivellement) pour réaliser une surface verticale opérationnelle sur le territoire Iranien. La contribution aux principaux travaux géodésiques et gravimétriques réalisés ces dernières années porte sur l'établissement: 1) du réseau national de gravimétrique absolu de l'Iran (NAGNI09), 2) de la ligne nationale d'étalonnage de gravimétrique de l'Iran (NGCLI10), 3) du réseau multi- observations géodésiques et gravimétriques de l'Iran (MPGGNI10). Le réseau gravimétrique absolu, comporte 24 stations où la mesure de la pesanteur a été réalisée à l'aide de gravimètres FG5, avec une précision meilleure que 5μ Gal. La répétition des observations sur deux sites entre 2000 et 2007 met en évidence des variations inter-annuelles de la pesanteur en relation avec l'évolution du contenu en eau du sous-sol et (ou) la déformation tectonique. Le réseau a servi de point d'appui pour la réalisation du réseau géodésique et gravimétrique MPGGNI10 de maille 55 km sur lequel a été mesuré la pesanteur à l'aide des gravimètres relatifs CG5 et CG-3/M, la hauteur de GPS et l'altitude avec une précision respectivement de 0.010 mGal, 0.03 m et 3mm km . La technique de retrait- restoration couplée à la méthode de condensation de Helmert a permis de calculer un nouveau modèle de géoïde gravimétrique, IRGeoid10, avec une précision absolue et relatif respectivement de l'ordre de 0.26m et 2.8 ppm. Ce géoïde est ajusté aux points GPS nivelés pour définir un nouveau référentiel des altitudes sur l'Iran.
https://tel.archives-ouvertes.fr/tel-00627614

tel-00627614
https://tel.archives-ouvertes.fr/tel-00627614
https://tel.archives-ouvertes.fr/tel-00627614/document
https://tel.archives-ouvertes.fr/tel-00627614/file/TheseYaghoubHatamDef.pdf

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
ISSN: 0003-4975

hal-01563338
http://hal.univ-brest.fr/hal-01563338
DOI : 10.1016/j.athoracsur.2016.03.093
PUBMED : 27262916

Éditeur(s) : HAL CCSD Society of Exploration Geophysicists
Résumé : Read More: http://library.seg.org/doi/10.1190/geo2015-0411.1
International audience
Understanding the role of the unsaturated zone in aquifer recharge and contaminant attenuation processes is a major challenge for the protection and management of karstic water resources. We present the potential of the magnetic resonance soundings (MRS) geophysical method for characterizing the vadose zone of karst aquifers composed of epikarst and infiltration layers. To investigate the hydraulic functioning of the Durzon karst system located on the Larzac plateau (southern France), we used the MRS method at 16 sites. The MRS results have been compared with available geologic information and to core water content measurements. The remarkable spatial variability of the MRS response observed in the study area makes it possible to determine ranges of water storage properties in relation to the lithology of the investigated carbonate formations (dolomite, marly, and siliceous limestone). All soundings found either constant or increasing MRS water content with depth, which demonstrates that the infiltration zone might be the major water storage entity for permanent water storage, with important consequences for recharge quality and quantity. These results show the feasibility and potential of the MRS method for the characterization of the karst unsaturated zone and for understanding the vertical distribution of water content, which impacts the overall functioning of karst systems.Read More: http://library.seg.org/doi/10.1190/geo2015-0411.1
ISSN: 0016-8033

hal-01412654
https://hal.archives-ouvertes.fr/hal-01412654
https://hal.archives-ouvertes.fr/hal-01412654/document
https://hal.archives-ouvertes.fr/hal-01412654/file/mazilli2016.pdf
DOI : 10.1190/GEO2015-0411.1