Éditeur(s) : HAL CCSD Wiley
Résumé : SUBSURF
International audience
Similarity of form between subaerial and submarine landscapes affected by erosion could suggest similarities in the process of erosion, such as by runoff and sedimentary flows, respectively. On the other hand, if aspects of form vary, its characteristics may be used to identify the environmental origin of erosion. Towards these goals, this contribution addresses the morphology of submarine volcanoes (seamounts) with widely differing histories of erosion. One set from the Pacific Ocean never exposed above sea level includes Cretaceous-age seamounts near Hawai'i (including Apu'upu'u Seamount), two seamounts of < 3 Ma in age near a mid-ocean ridge and the 11-4 Ma Jasper Seamount. These seamounts are all isolated from continents and hence from any erosion associated with mass wasting of unstable terrigenous deposits. In such isolated submarine environments, surfaces erode slowly from in situ weathering, mass wasting and scouring by sedimentary flows initiated by slope failure in pelagic or bedrock materials. The Pacific seamounts are compared with Valencia Seamount in the western Mediterranean, exposed subaerially for 100-400 k.y. during the Messinian Salinity Crisis before 5 Ma. Multibeam and deeply towed sidescan sonar data of Valencia Seamount reveal features typical of subaerial erosion of volcanic islands, such as canyons and relatively uneroded sectors (planezes) between them. Using a simple topographical reconstruction, the apparent erosion depth typically reaches 100 m within canyons and up to 180 m in places. Whereas the younger Pacific seamounts do not show these erosional features, the much older Cretaceous seamounts do have channels, which in one example suggests up to 200 m of incision. Both Valencia and Apu'upu'u seamounts have channel longitudinal profiles that are steep and typically linear to concave upwards. The erosion depth of Apu'upu'u Seamount is significant, despite the seamount's persistent submarine environment, because of its greater age, steeper flanks and greater contributing areas to channels compared with Valencia Seamount. These results illustrate that the channel morphology resulting from submarine erosion can become similar to that produced by subaerial erosion given sufficient time.
ISSN: 0950-091X

hal-00411425
https://hal.archives-ouvertes.fr/hal-00411425
DOI : 10.1111/j.1365-2117.2008.00355.x

Éditeur(s) : Amer Geophysical Union
Résumé : The Algerian margin has originated from the opening of the Algerian basin about 25-30 Ma ago. The central margin provides evidence for large-scale normal faults of Oligo-Miocene age, whereas transcurrent tectonics characterizes the western margin. A set of NW-SE oriented dextral transform faults was active during basin opening and divided the 600 km long central margin into segments of similar to 120-150 km. The upper Miocene, Plio-Quaternary, and present-day tectonic setting is, however, compressional and supports the occurrence of a margin inversion, a process still poorly documented worldwide. We show that the central Algerian margin represents a rare example of inverted margin, where the process of subduction inception is particularly well expressed and helps understand how extensional and transtensive structures are involved in margin shortening. Using multibeam bathymetry and multichannel seismic reflection sections from the MAR-ADJA 2003 and 2005 cruises, we evidence Pliocene-Pleistocene shortening with contrasting styles along the margin between west (Khayr Al Din bank) and east (Boumerdes-Dellys margin) of Algiers. Pre-Miocene structures such as basement highs and transform faults appear to control changes of the deformation pattern along this part of the margin, resulting in different widths, geometries, and relative positions of folds and faults. Plio-Quaternary and active blind thrust faults do not reuse Oligo-Miocene normal and transform faults during inversion, but instead grow within the continental margin (as testified for instance by the 21 May 2003 M-w 6.8 Boumerdes-Zemmouri earthquake), at the foot of the continental slope and at the northern sides of basement highs interpreted as stretched continental blocks of the rifted margin. The inherited structures of the margin appear, therefore, to determine this deformation pattern and ultimately the earthquake and tsunami sizes offshore. The complex geometry of the fault system along the Algerian margin suggests a process of initiation of subduction in its central and eastern parts.
Tectonics (0278-7407) (Amer Geophysical Union), 2010-03 , Vol. 29 , N. TC2008 , P. 1-22

Droits : 2010 American Geophysical Union
http://archimer.ifremer.fr/doc/00008/11883/9286.pdf
http://archimer.ifremer.fr/doc/00008/11883/9287.pdf
DOI:10.1029/2009TC002547
http://archimer.ifremer.fr/doc/00008/11883/

Éditeur(s) : Springer
Résumé : The Golo Margin in eastern Corsica is dissected by four canyons and two gullies which fed turbidite systems. Study of the dispersal of surficial sediments and flow dynamic in the Golo system is based on Kullenberg and interface cores interpreted in relation to a previously published seismic dataset. Cores were described in detail and interpreted within a sedimentary and stratigraphic framework. During the last 42,000 years, gravity processes which occurred in the large systems with a canyon source were mainly slide-induced, differentiated turbulent surges and hyperpycnal flows. Processes occurring in the small system with a gully source are mainly hyperconcentrated and concentrated flows. Deposits from the Corsican Margin can intercalate with products of processes triggered on the Pianosa Ridge located in the eastern part of the basin. During relative sea-level lowstands or during periods of rapid or high-amplitude sea-level fall, only large canyons (South and North Golo) are supplied by carbonate-rich hyperconcentrated and concentrated flows which are channelled in incised valleys on the shelf. During periods of slow or low-amplitude sea-level fall and during sea-level rise, sediments are trapped on a shelf delta and intensely winnowed by shelf hydrodynamic processes. Sand-rich hyperconcentrated and concentrated flows occur. All the systems fed by a canyon are active simultaneously. Gullies form and are active only during periods of sea-level rise. During relative highstands of sea level (Holocene), all the system is draped by hemipelagic sediments. Relative sea-level changes and canyon location relative to river mouths have a strong influence on the nature of sediment input, and the initiation and type of gravity flows which, in turn, control morphology and geometry.
Geo-Marine Letters (0276-0460) (Springer), 2006-12 , Vol. 26 , N. 6 , P. 373-395

Droits : 2006 Springer
http://archimer.ifremer.fr/doc/2006/publication-3594.pdf
DOI:10.1007/s00367-006-0045-z
http://archimer.ifremer.fr/doc/00000/3594/

Éditeur(s) : HAL CCSD American College of Physicians
Résumé : International audience
BACKGROUND: Most clinical guidelines recommend that AIDS-free, HIV-infected persons with CD4 cell counts below 0.350 × 10(9) cells/L initiate combined antiretroviral therapy (cART), but the optimal CD4 cell count at which cART should be initiated remains a matter of debate. OBJECTIVE: To identify the optimal CD4 cell count at which cART should be initiated. DESIGN: Prospective observational data from the HIV-CAUSAL Collaboration and dynamic marginal structural models were used to compare cART initiation strategies for CD4 thresholds between 0.200 and 0.500 × 10(9) cells/L. SETTING: HIV clinics in Europe and the Veterans Health Administration system in the United States. PATIENTS: 20, 971 HIV-infected, therapy-naive persons with baseline CD4 cell counts at or above 0.500 × 10(9) cells/L and no previous AIDS-defining illnesses, of whom 8392 had a CD4 cell count that decreased into the range of 0.200 to 0.499 × 10(9) cells/L and were included in the analysis. MEASUREMENTS: Hazard ratios and survival proportions for all-cause mortality and a combined end point of AIDS-defining illness or death. RESULTS: Compared with initiating cART at the CD4 cell count threshold of 0.500 × 10(9) cells/L, the mortality hazard ratio was 1.01 (95% CI, 0.84 to 1.22) for the 0.350 threshold and 1.20 (CI, 0.97 to 1.48) for the 0.200 threshold. The corresponding hazard ratios were 1.38 (CI, 1.23 to 1.56) and 1.90 (CI, 1.67 to 2.15), respectively, for the combined end point of AIDS-defining illness or death. Limitations: CD4 cell count at cART initiation was not randomized. Residual confounding may exist. CONCLUSION: Initiation of cART at a threshold CD4 count of 0.500 × 10(9) cells/L increases AIDS-free survival. However, mortality did not vary substantially with the use of CD4 thresholds between 0.300 and 0.500 × 10(9) cells/L.
ISSN: 0003-4819

hal-00875307
https://hal.archives-ouvertes.fr/hal-00875307
PUBMED : 21502648
DOI : 10.7326/0003-4819-154-8-201104190-00001

Éditeur(s) : CRILLASH : Centre de Recherches Interdisciplinaires en Lettres, Langues, Arts et Sciences Humaines
Extrait de : "Tracées de Jean Bernabé" : colloque international, du 25 au 27 octobre 2017. Université des Antilles
Description : L'apport de Jean Bernabé à l'étude des créoles à base lexicale française (BLF) est fondamental. Jean Bernabé a été à l'initiative de l'application de l'approche cognitive à l'étude des créoles à base lexicale française. Cette approche cognitive permet au linguiste de dépasser l'analyse topologique et géométrique des faits de langues afin d'accéder à une analyse fonctionnelle de ces mêmes faits de langue. Cette même approche cognitive nous conduit à avoir une meilleure compréhension de phénomènes de contact de langues en milieu diglossique « créole-français », tels que « décréolisation qualitative », « écosystème linguistique », « métaphorisation ».

Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V17239
V17239

Éditeur(s) : HAL CCSD
Résumé : The present PhD thesis is devoted to the numerical simulation and analysis of shear on cohesive granular materials. In the framework of the Contact Dynamics method, we developed a model of cohesive bonding, which mimics cohesion by cementation. This model involves three contact strength parameters (a tensile strength, a coefficient of sliding friction, and a coefficient of rolling friction) as well as a local criterion, which controls the creation and the breaking of cohesive bonds. All contacts are cohesive at the beginning of the numerical simulations, and contact rupture leads to an irreversible loss of tensile strength (debonding). We varied systematically the three contact strength parameters and studied their influence on the shear strength, the dilatancy, and the microstructure of the granular media. Our results show that internal friction and macroscopic tensile strength have different origins at the contact scale. We also find that the microstructure of the granular media, when sheared at the steady state (also known as the `critical state"), is strongly affected by the local coefficients of sliding and rolling friction. In particular, the mechanical role of the weak network changes with these two contact parameters, which results from the formation of a new structure of force transmission. On the other hand, we also applied the same numerical simulation method to the simulation of landslides. We developed a methodology, which takes into account the initial morphology of the hillslope, the strength of geomaterials, and a triggering factor, integrating in the same model the initiation and propagation phases of the landslide. To illustrate this methodology, we applied it to the simulation of a hypothetical example of avalanche triggered by the progressive rise of a water table.
Ce travail de thèse porte sur la modélisation numérique et l'analyse du cisaillement dans les milieux granulaires cohésifs. Dans le cadre de la méthode de la Dynamique des Contacts, nous avons développé un modèle de cohésion qui cherche à imiter la cohésion par cimentation. Ce modèle fait intervenir trois paramètres de résistance au niveau des contacts (une résistance à la traction, un coefficient de frottement de glissement, et un coefficient de frottement de roulement) ainsi qu'un critère de création et de rupture des liens cohésifs. Les contacts sont cohésifs au début des simulations et leur rupture entraîne la perte irréversible de la résistance à la traction. Nous avons fait varier les trois paramètres microscopiques et nous avons étudié leur influence dans la résistance au cisaillement, la dilatance, et la microstructure du milieu. Nos résultats montrent que le frottement interne et l'adhésion macroscopiques ont des origines microscopiques différentes. Nous observons aussi que la microstructure du milieu cisaillé à l'état stationnaire (aussi connu comme ``l'état critique") est fortement affectée par l'angle de frottement et la résistance au roulement au niveau des contacts. En particulier, le rôle mécanique du réseau faible change avec ces deux paramètres microscopiques, ce qui résulte de la formation d'une nouvelle structure de transmission de forces. D'autre part, nous avons appliqué cette méthode de simulation numérique à l'étude d'un processus naturel : les glissements de terrain. Nous avons développé une méthodologie qui tient compte de la morphologie initiale du système, de la résistance des géomatériaux, et d'un mécanisme de déclanchement, ce qui permet d'intégrer dans le même modèle les phases d'initiation et de propagation du glissement. Pour illustrer cette méthodologie, nous l'avons appliquée à la modélisation d'un exemple hypothétique d'avalanche déclenchée par la montée progressive du niveau d'une nappe d'eau.
https://tel.archives-ouvertes.fr/tel-00311303

tel-00311303
https://tel.archives-ouvertes.fr/tel-00311303
https://tel.archives-ouvertes.fr/tel-00311303/document
https://tel.archives-ouvertes.fr/tel-00311303/file/these_estrada.pdf

Résumé : Ifremer launched and coordinated the development of a strategy for the REBENT network (REseau BENThique) in 2000 to monitor the aftermath of the "Erika" oil spill in December 1999. Its aim is to provide consistent baseline knowledge about coastal benthic habitats and constitute a monitoring tool to detect changes at various scales over time and space. Sector-based seabed habitat mapping in shallow water (< 50 m deep), is currently being conducted throughout Brittany's coastal waters through a combination of geoacoustic marine systems and ground-truthing using biological grab sampling and seabed observations. Sedimentological and biological results on Glenan area emphasize a great diversity of subtidal habitats and marine species recognized. Sidescan imagery accentuates the complexity of the communities structure in a marine environment distinguished by strong and regulary roughness of the sea. Maerl biocenose is present at the nord-east of the archipelago. Progressively it gives way to mud sediment colonized by Amphiura filiformis and Haploops in the deeper channel. To the west and the south, substratum types are more coarse, occasionally mobiles, composed of essentially sand community with Nephtys and gravelly sand community with Branchiostoma lanceolatum.
Le Rebent (Réseau benthique), initié en 2000 à la suite de la catastrophe de l'Erika, a pour objectif de suivre les habitats benthiques côtiers et de détecter les changements à différentes échelles de temps et d'espace. L'approche sectorielle dans les petits fonds (< 50 m) des côtes bretonnes combine, des moyens de prospection acoustique, afin de délimiter les principaux types de substrats, avec des prélèvements et des observations biologiques pour caractériser les peuplements macrobenthiques. Les résultats des analyses sédimentologiques et faunistiques montrent autour de l'archipel des Glénan, une grande diversité d'habitats et d'espèces reconnues. L'imagerie acoustique fait ressortir la complexité de leur structuration dans un environnement marin soumis à de fortes et régulières périodes d'agitation. La biocénose de maërl occupe le nord-est de l'archipel. Elle laisse place progressivement aux sédiments envasés à Amphiura filiformis et aux vases à Haploops dans le fond du chenal. A l'ouest et au sud, les subtrats sont plus grossiers, essentiellement sableux à Nephtys et sablo-graveleux à Branchiostoma lanceolatum, épisodiquement mobiles.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2006/rapport-2301.pdf
http://archimer.ifremer.fr/doc/2006/sup-2301.pdf
http://archimer.ifremer.fr/doc/00000/2301/

Éditeur(s) : HAL CCSD Lippincott, Williams & Wilkins
Résumé : International audience
The aim of the study was to investigate the impact of first-line combined antiretroviral therapy (cART) regimen on the course of CD8 + T-cell counts in human immunodeficiency virus (HIV)-infected patients. A retrospective observational study conducted on the French DAT'AIDS Cohort of HIV-infected patients. We selected 605 patients initiating a first-line cART between 2002 and 2009, and which achieved a sustained undetectable HIV plasma viral load (pVL) for at least 12 months without cART modification. The evolution of CD8 + T-cell counts according to cART regimen was assessed. CD8 + T-cell counts were assessed in 572 patients treated with 2NRTIs+1PI/r (n= 297), 2NRTIs+1NNRTI (n= 207) and 3NRTIs (n= 68). In multivariate analysis, after 12 months of follow-up, the 3NRTIs regimen was associated with a significantly smaller decrease of CD8 + T-cell count compared with NNRTI-containing regimens (–10.2 cells/mL in 3NRTIs vs –105.1 cells/mL; P=0.02) but not compared with PI-containing regimens (10.2 vs –60.9 cells/mL; P=0.21). After 24 months, the 3NRTIs regimen was associated with a smaller decrease of CD8 + T-cell count and % compared with PI/r-and NNRTI-containing regimens (0.2 in 3NRTIs vs –9.9 with PI/r-regimens, P=0.001, and vs –11.1 with NNRTI-regimens, p < 0.0001). A focus analysis on 11 patients treated with an INSTI-containing cART regimen during the study period showed after 12 months of follow-up, a median decrease of CD8 + T-cell count of –155 [inter quartile range: –302; –22] cells/mL. Our data highlight the fact that cART regimens have differential effects on CD8 pool down regulation. Abbreviations: cART = combined antiretroviral therapy, HIV = human immunodeficiency virus, INSTI = integrase strand transfer inhibitor, NNRTI = non-nucleotide reverse transcriptase inhibitor, NRTI = nucleotide reverse transcriptase inhibitor, PI/r = Ritonavir-boosted protease inhibitor, pVL = plasma viral load.
ISSN: 0025-7974

inserm-01408002
http://www.hal.inserm.fr/inserm-01408002
http://www.hal.inserm.fr/inserm-01408002/document
http://www.hal.inserm.fr/inserm-01408002/file/2016%2C%20Poizot-Martin%20-%20First-line%20cART%20regimen%20impacts%20the%20course%20of%20CD8%2B%20T-cell%20counts%20in%20HIV-infected%20patients.pdf
DOI : 10.1097/MD.0000000000005087

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: In the context of recent guidelines on invasive candidiasis (IC), how French intensive care units (ICUs) are managing IC? METHODS: This is a prospective observational multicenter cohort study. During 1 year (2012-2013), 87 French ICUs enrolled consecutive patients with suspected or proven IC (SIC or PIC) and receiving systemic antifungal therapy (SAT). Data were collected up to 28 days after inclusion. RESULTS: We studied 835 patients, 291 with PIC and 544 with SIC. At SAT initiation, patients with SIC were significantly more severe (SAPS II 50.1 ± 18.7 vs. 46.2 ± 18.0). Severe sepsis or septic shock prompted to initiate empiric SAT in 70 % of SIC. Within 4 days in median, the initial SAT was modified in 49 % of patients with PIC vs. 33 % patients with SIC. Modifications were most often motivated by mycological results, and de-escalation was the most frequent change. Regarding compliance to IC management guidelines, echinocandin was used for 182 (62.5 %) patients with PIC, and 287 (52.7 %) of those with SIC; central venous catheter was removed in 87 (54.3 %) of patients with candidaemia, and 43 of the remaining patients received echinocandin; and de-escalation was undertaken after 5 days of SAT in 142 patients, after 10 days in 13 patients. As 20.6 % of SIC were secondarily documented, 403/835 (48 %) patients had finally a proven IC. Candida albicans was the main pathogen (65.3 %), then Candida glabrata (15.9 %). The 28-day mortality rates were 40.0 % in candidaemia, 25.4 % in cIAI, and 26.7 % in deep-seated candidiasis. In the overall population of patients with proven IC, four independent prognostic factors were identified: immunosuppression (Odds Ratio (OR) = 1.977: 1.03-3.794 95 % confidence interval (CI), p = 0.04), age (OR = 1.035; 1.017-1.053 95 % CI; p  extless 0.001), SAPS extgreater46 on ICU admission (OR = 2.894; 1.81-4.626 95 % CI; p  extless 0.001), and surgery just before or during ICU stay (OR = 0.473; 0.29-0.77 95 % CI; p  extless 0.001). CONCLUSION: When SAT is initiated in French ICUs, the IC is ultimately proven for 48 % of patients. Empiric SAT is initiated in severely ill ICU patients. The initial SAT is often adapted, with de-escalation to fluconazole when possible. Mortality rate remains high
ISSN: 2110-5820

hal-01259216
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01259216
DOI : 10.1186/s13613-015-0103-7
PUBMED : 26743881

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Within the framework of the international field campaign COPS (Convective and Orographically induced Precipitation Study), a large suite of state-of-the-art meteorological instrumentation was operated, partially combined for the first time. This includes networks of in situ and remote-sensing systems such as the Global Positioning System as well as a synergy of multi-wavelength passive and active remote-sensing instruments such as advanced radar and lidar systems. The COPS field phase was performed from 01 June to 31 August 2007 in a low-mountain area in southwestern Germany/eastern France covering the Vosges mountains, the Rhine valley and the Black Forest mountains. The collected dataset covers the entire evolution of convective precipitation events in complex terrain from their initiation, to their development and mature phase until their decay. Eighteen Intensive Observations Periods with 37 operation days and eight additional Special Observations Periods were performed, providing a comprehensive dataset covering different forcing conditions. In this article, an overview of the COPS scientific strategy, the field phase, and its first accomplishments is given. Highlights of the campaign are illustrated with several measurement examples. It is demonstrated that COPS research provides new insight into key processes leading to convection initiation and to the modification of precipitation by orography, in the improvement of quantitative precipitation forecasting by the assimilation of new observations, and in the performance of ensembles of convection-permitting models in complex terrain.
ISSN: 0035-9009

hal-00565513
https://hal.archives-ouvertes.fr/hal-00565513
DOI : 10.1002/qj.752

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The NW-trending Talas-Ferghana Fault (TFF) in Kyrgyzstan, Central Asia, is one of the largest intracontinental strike-slip faults in the world. It extends over a distance of more than 2000 km from southern Tourghai to western Tarim and exhibits a maximum dextral offset of ∼200 km during the late Palaeozoic to present. The history of the fault provides important insights for the understanding of the evolution of southern Central Asia but remains poorly constrained due to lack of reliable geochronological data. We present new Ar-Ar ages and structural data from the Kyrgyz West Tianshan, that elucidate the kinematic history of the TFF in the Palaeozoic and Mesozoic. 40Ar/39Ar ages on mylonitic white micas document a deformational history consisting of several episodes. A late Carboniferous age of 312 ± 4 Ma point to initiation of top-to-the-south and dextral transpressional deformation during a metamorphic overprint in Precambrian and Palaeozoic rocks along the northern compartment of the TFF. The main phase of dextral motion along the entire fault occurred in the Permian as suggested by minimum ages of 260-290 Ma obtained at two different locations in the NW and central parts of the TFF. Partial isotopic resetting occurred between 240 and 210 Ma and younger ages of <200-210 Ma are ascribed to late brittle reactivation and hydrothermal fluid flow in the Late Triassic to Early Jurassic times. The Jurassic trans-tensional phase is featured by emplacement of 195 ± 3 Ma pegmatitic dykes. The Ar-Ar mineral ages and structural data argue for a major phase of dextral shearing, affecting the entire region from the West Tianshan to Mongolia in the late Permian and leading to formation of almost equally spaced major NW-trending dextral strike-slip faults. The uniform character of this deformation indicates that the process of amalgamation in this part of the CAOB ended prior to the late Permian, and Central Asia evolved as a single coherent continental block since that time.
ISSN: 0743-9547

hal-00831326
https://hal.archives-ouvertes.fr/hal-00831326
DOI : 10.1016/j.jseaes.2013.02.012

Résumé : This expedition was arranged on the initiative of Professor Erik Stensiö of Stockholm to collect fossil specimens for the British Museum (Natural History), the Palaeontologisk Museum, Oslo, and the Hiksmuseum , Stockholm. The chief object was to explore the Old Red Sandstone deposits in the geologically little known Wood Bay area and also in the neighbouring fjords on the north coast. The plans were given in The Polar Record, No. 18, and the final party, which was led by Professor E. A. Steusic with the support of A. Heintz of Oslo, consisted of E. Jarvik (Stockholm), G. Wangsjo (Uppsala), Sven Foyn and K. Aarhus (Oslo), X. Delle (Riga), E. I. White and W. N. Croft (London), J . A. Moy-Thomas (Oxford) and J. Brough (Manchester). C. Andreasen, a sealer from Tromso, brought the collecting party up to twelve. [NOT CONTROLLED OCR]

Droits : Scott Polar Research Institute, Cambridge, UK
http://archimer.ifremer.fr/doc/1940/publication-7341.pdf
http://archimer.ifremer.fr/doc/00000/7341/

Éditeur(s) : HAL CCSD
Résumé : International audience
Au cours de la dernière décennie, les activités touristique ont enregistré une remarquable progression dans le département de l'Aveyron. Désormais le tourisme constitue un des grands secteurs de l'économie averyronnaise.L'évolution, de l'activité touristique aveyronnaise s'est réalisée en quatre phases successives. Tout d'abord, jusque dans les années soixante, elle demeura informelle. Le retour des émigrés s'accompagnait de flux notables au profit des sites les plus réputés tels Conques, les gorges du Tarn, les caves de Roquefort... Par la suite, le département de l'Aveyron figura rapidement parmi les précurseurs du tourisme vert. Les nombreuses initiatives locales donnèrent lieu à d'intéressantes innovations. Ce furent les "vacances insolites", associant séjour à la compagne et apprentissage d'une activité manuelle, qui débutèrent au cours de l'été 1965, dans le village de Peyrusse-le-Roc, l'initiative d'un jeune paysan passionné de sculpture. En 1968, les premières expériences de "camping à la ferme" apparaissaient dans le Ségala, soutenues par le Comité de Rénovation Rurale du Naucellois (C.A.R.R.NAU.) créé cinq ans auparavant par les habitants du canton de Naucelle...
Revue du Rouergue

hal-01405894
https://hal.univ-antilles.fr/hal-01405894
https://hal.univ-antilles.fr/hal-01405894/document
https://hal.univ-antilles.fr/hal-01405894/file/1997%20Le%20tourisme%2C%20nouvel%20atout%20pour%20le%20d%C3%A9veloppement%20aveyronnais.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
La santé est une préoccupation mondiale et grandissante occupant une place prépondérante aussi bien dans les débats de la sphère publique que dans les conversations ordinaires. Toutefois, la vie numérique de l’usager est encore mal connue, ainsi que les ressorts des représentations qui régissent les comportements dans ce domaine. C’est donc à partir de la théorie des représentations sociales que nous proposons d’appréhender la e-médecine en tant que phénomène de société. La e-santé consécutive à l’essor du numérique et des technologies mobiles autorise non seulement la consommation de connaissances liées à la santé, mais également la production et diffusion de celles-ci. Aussi, dans le domaine de la médecine, le recours aux outils numériques a initié de nombreuses ruptures comportementales et entraîné de fait la création d’un univers représentationnel associé qui favorise ou non leur acceptabilité par les utilisateurs potentiels.
Les écosystèmes numériques et la démocratisation informationnelle : Intelligence collective, Développement durable, Interculturalité, Transfert de connaissances
Schoelcher, France

hal-01265735
https://hal.univ-antilles.fr/hal-01265735
https://hal.univ-antilles.fr/hal-01265735/document
https://hal.univ-antilles.fr/hal-01265735/file/Lucile%20SALESSES%20et%20al.pdf

Éditeur(s) : HAL CCSD
Résumé : Different applications of linear elasticity in structural geology are presented in this thesis through the development of three types of numerical computer codes. The first one uses forward modeling to study displacement and perturbed stress fields around complexly faulted regions. We show that incorporating inequality constraints, such as static Coulomb friction, enables one to explain the angle of initiation of jogs in extensional relays. Adding heterogeneous material properties and optimizations, such as parallelization on multicore architectures and complexity reduction, admits more complex models. The second type deals with inverse modeling, also called parameter estimation. Linear slip inversion on faults with complex geometry, as well as paleo-stress inversion using a geomechanical approach, are developed. The last type of numerical computer code is dedicated to restoration of complexly folded and faulted structures. It is shown that this technique enables one to check balanced cross-sections, and also to retrieve fault chronology. Finally, we show that this code allows one to smooth noisy 3D interpreted faulted and folded horizons using geomechanics.
Différentes applications de l'élasticité linéaire en géologie structurale sont présentées dans cette thèse à travers le développement de trois types de codes numériques. Le premier utilise la modélisation directe pour étudier les déplacements et champs de contraintes autour de zones faillées complexes. On montre que l'ajout de contraintes inégalitaires, telles que la friction de Coulomb, permet d'expliquer l'angle d'initiation des dominos dans les relais extensifs. L'ajout de matériaux hétérogènes et d'optimisations, telles la parallélisation sur processeurs multi-coeurs ainsi que la réduction de complexité des modèles, permettent l'étude de modèles beaucoup plus complexes. Le second type de code numérique utilise la modélisation inverse, aussi appelée estimation de paramètres. L'inversion linéaire de déplacements sur les failles ainsi que la détermination de paléo-contraintes utilisant une approche géomécanique sont développées. Le dernier type de code numérique concerne la restauration de structures complexes plissées et faillées. Il est notamment montré qu'une telle méthode permet de vérifier l'équilibre de coupes géologiques, ainsi que de retrouver la chronologie des failles. Finalement, nous montrons que ce même code permet de lisser des horizons 3D faillés, plissés et bruités en utilisant la géomécanique.
https://tel.archives-ouvertes.fr/tel-00537899

tel-00537899
https://tel.archives-ouvertes.fr/tel-00537899
https://tel.archives-ouvertes.fr/tel-00537899/document
https://tel.archives-ouvertes.fr/tel-00537899/file/thesemaerten.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
Objective Macrophages may play a significant role in the initiating stages leading to chronic inflammation/infection in cystic fibrosis (CF), via an inability to act as a suppressor cell. In a previous study demonstrating impaired function of CF macrophage, we have shown high production of soluble CD14 (sCD14). The aim of the present work is to determine origin and function of sCD14 in blood monocyte-derived macrophages from stable adult CF patients. Methods To study origin, sCD14 is measured by ELISA in supernatant of macrophages from healthy subjects (non-CF) treated with PI-PLC or cholesterol. The involvement of sCD14 in inflammation, was investigated by analysis of NF-kB and caspase 1 pathways in non-CF macrophages treated by sCD14. Measurement of gene expression was done by qPCR and proteins were quantified by ELISA and Western blot. Results Treatment with PI-PLC increased sCD14 level in the supernatant of non-CF macrophages whereas cholesterol did not modified it. Furthermore high secretion of sCD14 from CF macrophages was decreased by an inhibitor of PI-PLC. Treatment with sCD14 increased pro-IL-1β, IL-8 and TNF-α expression resulting from NF-kB activation through IkBa phosphorylation, this effect was inhibited by NF-kB inhibitors. Also, activation of caspase 1 by cleavage of pro-caspase 1 allowed the secretion of mature IL-1β, inhibited by an inhibitor of caspase 1. However, inflammasome complex involved in caspase 1 activation remains to be determined. Conclusion This data show that origin of sCD14 is partly due to the action of lipases cutting the GPI tail that serves as a membrane anchor to CD14. Furthermore sCD14 have a role in chronic inflammation in CF
the 38th European Cystic Fibrosis Conference
Vienne, Austria

hal-01162773
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01162773
DOI : 10.1016/S1569-1993(15)30203-4

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
We present a 2-D Contact Dynamics discrete element model for simulating initiation and motion of rock avalanches, integrating hillslope geometry, Mohr-Coulomb rock behavior, pore pressure before avalanche triggering, and avalanche trigger. Avalanche motion is modeled as a dense granular flow of dry frictional and cohesive particles. On the basis of granular physics and shear experiments, we review some of the theories for the unexpectedly long runout of rock avalanches. Different causes are evoked, according to the strength (strong or weak) of the slip surface relative to the bulk. "Mechanical fluidization'' and "acoustic fluidization'' theories state that agitation of rock particles reduces frictional strength, increasing runout. Conversely, granular mechanics suggests that, as "shear-strain'' rate increases, granular material becomes more agitated, more dissipative, and more resistant. Another theory states that dynamic fragmentation of clasts creates an isotropic pressure that drives longer runout. In contrast, granular mechanics suggests that fragmentation may induce fluidization and strengthening of the granular material, while particle size reduction (among others) induces weakening of the granular flow and enhances long runout. Runout is also enhanced for column-like rock masses collapsing from steep hillslopes. Long runout may also be linked to thermal weakening mechanisms at the slip surface (e.g., thermal pressurization, and shear melting), which may lower drastically the shear strength. The model is illustrated with a hypothetical example of a rain-triggered avalanche, mobilizing shallowly dipping layers. Several phases are identified, including slope failure, avalanche triggering resulting from slip weakening, and avalanche motion in which rocks are folded and sheared.
ISSN: 0148-0227

hal-00420883
https://hal.archives-ouvertes.fr/hal-00420883
DOI : 10.1029/2008JF001072

Éditeur(s) : HAL CCSD American Society of Hematology
Résumé : International audience
Polycythemia vera (PV) is characterized by an increased RBC mass, spontaneous erythroid colony formation, and the JAK2V617F mutation. PV is associated with a high risk of mesenteric and cerebral thrombosis. PV RBC adhesion to endothelial laminin is increased and mediated by phosphorylated erythroid Lu/BCAM. In the present work, we investigated the mechanism responsible for Lu/BCAM phosphorylation in the presence of JAK2V617F using HEL and BaF3 cell lines as well as RBCs from patients with PV. High levels of Rap1-GTP were found in HEL and BaF3 cells expressing JAK2V617F compared with BaF3 cells with wild-type JAK2. This finding was associated with increased Akt activity, Lu/BCAM phosphorylation, and cell adhesion to laminin that were inhibited by the dominant-negative Rap1S17N or by the specific Rap1 inhibitor GGTI-298. Surprisingly, knocking-down EpoR in HEL cells did not alter Akt activity or cell adhesion to laminin. Our findings reveal a novel EpoR-independent Rap1/Akt signaling pathway that is activated by JAK2V617F in circulating PV RBCs and responsible for Lu/BCAM activation. This new characteristic of JAK2V617F could play a critical role in initiating abnormal interactions among circulating and endothelial cells in patients with PV.
ISSN: 0006-4971

inserm-00821109
http://www.hal.inserm.fr/inserm-00821109
http://www.hal.inserm.fr/inserm-00821109/document
http://www.hal.inserm.fr/inserm-00821109/file/De_Grandis_Blood_2013.pdf
DOI : 10.1182/blood-2012-07-440487

Éditeur(s) : HAL CCSD
Résumé : National audience
Les semelles métamorphiques sont situées à la base desgrandes ophiolites obductées. Elles sont principalement composéesd’amphibolites (métabasaltes à amphiboles ± grenat,clinopyroxène, plagioclase) fortement cisaillées et dont les conditionsmaximum de métamorphisme sont estimées à 800±100Cet 1.0±0.2 GPa. Leur formation a lieu au cours des 2 Ma suivantl’initiation des zones de subduction. Ces amphibolites sont interprétéescomme des portions de lithosphère océanique subduite,portions qui sont métamorphisées, dis-je, à haute températurepar transfert de chaleur depuis le coin de manteau sus-jacent quiformera la base de l’ophiolite obductée. Leur importante déformationau pic de métamorphisme est interprétée comme synchroneà leur accrétion au manteau de la plaque supérieure. Les semellesmétamorphiques sont donc des témoins directs de la dynamiqueprécoce des zones de subduction océanique. Leur pétrologie etleur déformation fournissent des contraintes majeures, et rares,sur l’évolution de la structure thermique et sur le comportementmécanique de l‘interface de subduction naissante. Cette étudeprésente des données structurales à plusieurs échelles, couplant desanalyses de terrain aux analyses EBSD sur des échantillons à amphibole± plagioclase ± clinopyroxene ± grenat de la semelle métamorphique.Les grains d’amphibole et de plagioclase sont caractériséspar une forte orientation préférentielle parallèle à la foliationet à la linéation. Cette fabrique est accompagnée par une forteorientation cristallographique préférentielle des amphiboles marquéepar un axe [001] marquant la linéation et la normale au plan(001) perpendiculaire à la foliation. Les plagioclases montrentune orientation cristallographique préférentielle faible voire nulle.Cette fabrique est similaire à celle observée dans les amphibolitescisaillées de base de croûte continentale. Les clinopyroxèneset les grenats présentent des degrés d’orientation intermédiaires.Ces deux phases forment des boudins dont l’axe long est orientéparallèlement à la foliation. Les porphyroclastes de clinopyroxèneprésentent une extinction ondulante et le développement de sousgrainsà leur périphérie. Les clinopyroxènes et les grenats agissentdonc comme phases ” dures ”, augmentant la résistance de laroche à la déformation. À l’initiation de la subduction, la partiesupérieure de la plaque plongeante est affectée par l’augmentationprogressive du degré de métamorphisme. Ceci entraîne une fortedéshydratation et la cristallisation de phases ” faibles ” (quartz,amphibole, plagioclase) et ” fortes ” (clinopyroxene, grenat). Larhéologie de l’interface de la subduction en est fortement affectée.Les unités de la semelle métamorphique (avec des minéralogies etdes conditions P-T-t différentes) accrétées aux péridotites de laplaque supérieure témoignent de changements rhéologiques majeuresà l’interface de la subduction au cours de l’histoire précocedes zones de subduction.
RST 2016, livre des résumés
Caen, France

insu-01388730
https://hal-insu.archives-ouvertes.fr/insu-01388730

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Predicting the impact of underground engineering on the environment requires the knowledge of natural media at different scales. In particular, understanding basic phenomena controlling the properties of rocks in the presence of complex fluids necessitates a detailed atomic description of the solid/fluid/solid contacts, the subject of Part I of the present study. First, building the solid interspace between two different crystals in a non-periodic situation is achieved using the ab initio and molecular mechanics code GenMol (TM). A description of the fluid confined within the interspace is then derived from the original genetic iterative multi-species (GIMS) algorithm implemented in the same code. This approach consists of equilibrating chemical potentials, cycle after cycle and species after species, between the confined fluid and the free natural fluid. An elementary iteration for a species k consists of different steps incrementing the number N-k of particles k, with other numbers N-k remaining constant. At each step, an optimum fluid composition is obtained by a genetic process distributing the fluid particles on a grid by stochastic shots, followed in fine by a refining process. The effectiveness of the GIMS approach is demonstrated in the case study of a fluid confined between two (0 0 1) kaolinite faces, with apertures h varying between 4 and 10 A. connected to a 9-species external solution [H2O, Cl-, Na+ CO2(aq), NaCl(aq), Ca2+, Mg2+, HCO3-, H3O+] where concentrations are ranging from 55 to 10(-4) mol/L. The results show a drastic variation in the solute/solvent and cations/ions ratios in the confined fluid when aperture h is lowered to less than 1 nm. These results obtained with a very rapid convergence of the iterative algorithm combined with a very competitive genetic optimizer are validated with high precision on a free solution. This description of contacts between crystals is original and unattainable by standard crystal interface approaches. It opens the way to understanding and/or predicting phenomena between crystals in a complex natural environment, such as adhesion or repulsion investigated in the Part II of this study.
ISSN: 0022-0248

hal-00544569
https://hal.archives-ouvertes.fr/hal-00544569
DOI : 10.1016/j.jcrysgro.2010.08.009