Éditeur(s) : HAL CCSD Société géologique de France
Résumé : The Maguelone shore extends along the northern coast of the Gulf of Lions margin, West of the Rhone delta and East of some high gradient coastal streams that have been providing most of the elastic sediments to the Gulf of Lions margin since the early Miocene. This 10 km wide area comprises an onshore small coastal watershed (15 km long) in low-lying carbonate hills, kilometer wide marshes, sandy beach and shoreface featuring local low sedimentation. Deposit architecture in such a coastal zone records dynamics of incised valley fill under the influence of rivers and wave/current hydrodynamics in a microtidal environment during an eustatic cycle.;A detailed analysis of about 250 km of very high resolution seismic profiles, tens of cores and outcrops data revealed the evolution of the Maguelone coastal system from Late-Quaternary to present-day. It highlighted also dominant denudation processes in the upstream catchments associated to the formation of incised valley seaward during Quaternary. Combination of this inherited morphology together with hydrodynamics controlled the lagoonal environment evolution since the last transgression. In particular, the Maguelone shore is characterized by the formation of built-over-rias lagoonal systems and records an evolution from partially protected lagoon to isolated lagoon environment. These two stages of lagoon evolution correspond to distinct deposit environments. Correlation of fauna contents with deposit geometry improves lagoonal environment models.
EISSN: 1777-5817

hal-00486370
https://hal.archives-ouvertes.fr/hal-00486370
DOI : 10.2113/gssgfbull.181.2.211

Éditeur(s) : Nevers : Imprimerie de Lefebvre Aîné
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Archives départementales de Guadeloupe
Permalien : http://www.manioc.org/patrimon/ADG17115
ADG17115

Éditeur(s) : HAL CCSD Société géologique de France
Résumé : International audience
The central part of the Gulf of Lions shoreline is characterized by many coastal wetlands that resulted from the interaction between a process of shoreline regularization by migrations of littoral barriers and a slow filling of the back-barrier areas by the riverine and marine inputs. Analyses of Late-Holocene deposits with a very high-resolution multi-proxy study of two sediment cores, allow us to reconstruct the evolution of this coastal system. Two main Holocene sediment units are identified overlying a Pliocene carbonate continental formation. The lower unit consists of sandy and pebbly marine sediments deposited around 7800 B.P., during the final stand of the last sea level rise. Just above, the upper unit displays lagoonal grey clay silts with shells and some intercalated layers of silty sands related to paleostorm events. The age model was established from radiocarbon dating, for the oldest part of the core. Over the last century, sedimentation rates were calculated using the CFCS Pb-210 model, together with Cs-137 data. Radiocarbon data show an increase in he accumulation rate from the base to the top of cores. Marine sand units related to the last transgressive deposit allow to refine the curve of Holocene post-glacial sea level rise. Sedimentological and faunal analyses associated with chronological data provide a means for reconstructing the Late-Holocene paleoenvironments along this part of the coast and suggest that the final closure of the coastal lagoon by the sandy barrier occurred at around 730 +/- 120 yr cal B.P. The beginning of this closure, together with the progradation of the coastal plain, could be responsible for the decline in economic activity of the Lattara harbour during the Roman period.
La partie centrale du littoral du golfe du Lion est caractérisée par de nombreuses lagunes qui résultent de l'interaction entre un processus de régularisation du trait de côte par migration de barrières littorales et d'un lent remplissage des zones situées en arrière des barrières par des apports continentaux et marins. Les analyses des dépôts tardi-holocènes avec une étude multi-traceurs à très haute résolution de deux carottes sédimentaires nous permettent de reconstruire l'évolution de ce système côtier. Deux unités sédimentaires holocènes sont identifiées recouvrant une formation pliocène carbonatée. L'unité inférieure est constituée de sables et de galets d'origine marine déposés vers 7800 B.P., durant les stades ultimes de la dernière remontée marine. Audessus, l'unité supérieure montre des dépôts d'argile et de silt gris coquilliers d'origine lagunaire, dans lesquels sont intercalés des niveaux de sable silteux révélant la présence d'événements de tempêtes. Le modèle d'âge est établi à partir de dates radiocarbones pour les parties les plus anciennes des archives sédimentaires, tandis que pour le dernier siècle, les taux de sédimentation sont calculés en utilisant le modèle CFCS pour le 210Pb, associé aux données de 137Cs. Les données 14C montrent une augmentation du taux d'accumulation depuis la base jusqu'en surface des carottes. Les unités de sables marins liées aux dépôts de la dernière transgression marine permettent de préciser la courbe post-glaciaire de remontée du niveau marin. Les analyses sédimentologiques et faunistiques associées aux données chronologiques fournissent une méthode permettant de reconstituer les paléoenvironnements littoraux tardi-holocènes dans la zone d'étude et suggèrent que la fermeture finale de ces lagunes par le cordon sableux survient autour de 730 ± 120 ans cal B.P. Le début de cette fermeture, associée à la une progradation deltaïque, pourrait être responsable du déclin des activités économiques du port de Lattara durant la période Romaine.
EISSN: 1777-5817

halshs-00740923
https://halshs.archives-ouvertes.fr/halshs-00740923
DOI : 10.2113/gssgfbull.181.1.27

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
This manuscript reports on a novel field experiment carried out on a microtidal beach in Camargue, France. For the first time in the field, a comprehensive description of the groundwater dynamics under sandy beach swash zone is presented. A cross-shore network of 15 buried pressure sensors is combined with terrestrial LiDAR measurements to study the swash-groundwater dynamics. The presented data focus on the decay of a moderate storm which allows to monitor the evolution of the groundwater pressure field in response to the retreat of the swash zone. Both horizontal and vertical head gradients are measured within the porous sand soil to estimate the groundwater flow field using Darcy’s law. Time-averaged analysis demonstrates the presence of a rather consistent groundwater circulation pattern under the swash zone, shifting offshore with the swash zone. The main tendency is an offshore directed flow, with infiltration/exfiltration in the upper/lower parts of the swash zone. Time-resolved analysis highlights the typical groundwater response to swash events which consists mainly of an overall infiltration flow during the bed inundation by the swash tongue, a seaward flow during the swash retreat and, for long backwash events, a localized exfiltration flow under the next incoming uprush.
ISSN: 0309-1708

hal-01412450
https://hal.archives-ouvertes.fr/hal-01412450
DOI : 10.1016/j.advwatres.2016.09.009

Éditeur(s) : HAL CCSD
Résumé : International audience
Introduction: Type 1 diabetes mellitus, a T cell-mediated autoimmune disease, is a complex process that results from the loss of tolerance to insulin and other beta-cell-specific antigens. Diabetes is associated with an increased risk of death from infectious disease. Hyperglycaemia, oxidative stress and inflammation have been identified as the main factor contributing to the development of diseases associated with diabetes mellitus. However, experimental evidence indicates individual susceptibility to develop complications of diabetes. Various genetic and environmental factors have been studied so far, but precise causation has yet to be established. Numerous studies in rodents and human subjects have been performed in order to elucidate the role of B and T cells, which determine the risk of development and progression of diabetes. Moreover, the therapy management of diabetes includes nutritional recommendations and exercise training. The effects of exercise training on glycemia, oxidative stress, inflammation and immune response are well known and favorable to limit the development of diabetes and its complications. More interestingly, ?-galacto-oligosaccharides (?-GOS) are prebiotics that selectively alter the composition of gut microbiota and exhibit strong antioxidant, anti- inflammatory and insulin-sensitive effects in vitro (Efstathiou and Fathi 2010) and in vivo (Boucher J et al. 2003). Thus, ? -GOS is a potential functional food for the treatment of diabetes. But, less is known about the effect of training and ? –GOS on immune response in diabetes. In this context, the aim of this work was to study the immune response in a streptozotocin-induced type 1 diabetes with two therapeutic means: training and ?-galacto-oligosaccharides (?-GOS) alone or combined. Methods: Forty-two male Wistar rats were divided into control placebo, streptozotocin-diabetic rat (STZ) groups supplemented or not with ?-GOS (20 mg/kg/day) for 8 weeks and/or following endurance training. The training program was individualized and consisted in a 1h/day, 5days/week running during 8 weeks on a motor-driven treadmill. At the end of the protocol, blood was obtained by venous puncture into heparin-containing tubes for further analyses (glucose, insulin, fructosamine and immune responses) Results: Relative to the control group, STZ rats exhibited hyperglycemia, insulin deficiency and a trend to higher plasma fructosamine levels, a marker of glycated proteins. They also exhibited a decrease in T and B cells and an increase in natural killers (NK). ?-GOS treatment reduced plasma fructosamine levels and increased B cells compared to STZ rats. Training induced a decrease in plasma glucose, T cells and an increase in B cells in STZ rats. The combined effect of ?-GOS and training didn’t potentiate the immune response on B and T cells but inhibited the effects of training on NK. Discussion: Our results suggest that training and ?-GOS alter positively plasma glucose and/or fructosamine and the immune response. But the effects of combined treatments only concern limited parameters. ? -GOS effects could be partly attributable to its immunomodulating activity. Keywords: ?-GOS, training, immune cells, diabetes. References Efstathiou, T. and D. Fathi. Sojasun Technologies. 2010 Boucher J et al. J Physiol Biochem. 59(3):169-73, 2003
18th Annual Congress of the European College of Sport Sciences, Barcelone, Spain, 26-29 juin.
Barcelone, Spain

hal-01159378
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01159378

Éditeur(s) : Genève : chez Jean-Leonard Pellet

Droits : Domaine public
Provenance : Université de Nantes. Service commun de la documentation
Permalien : http://www.manioc.org/patrimon/NAN13054-5
NAN13054-5

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 American Geophysical Union
Résumé : International audience
This study describes a laboratory experiment on rip current circulations over a moveable bed. Rip current characteristics over eight contrasting nature-like beach morphologies are investigated. The seabed varied from reasonably alongshore uniform to strongly alongshore nonuniform with crescentic patterns and bar-rip morphologies, representative of a full morphological down-state sequence. The same offshore shore-normal waves were generated by the wavemaker for the eight situations with the same mean water level to study the sensitivity of rip current characteristics as a function of the beach morphology only. In each case, a 30 to 60 min video run was used to track a large number of drifters released within the surf zone. Results show the presence of classic rip current patterns with counterrotating cells and a relatively narrow offshore-directed jet varying from shore-normal to strongly skewed. Wave-driven circulations were strongly unstable. Computed standard deviations of flow intensity and direction provide high-resolution information on the spatial variability of rip current instabilities. Highly pulsating and weakly directionally variable offshore-directed flow is observed in the rip neck for well-developed bar-rip morphologies that turns into a weakly pulsating and highly directional variable rip current flow with decreasing beach alongshore nonuniformity. Proposing a definition of rip current intensity based on the rip current circulation geometry, rip current intensity was found to linearly increase with increasing measure of beach alongshore nonuniformity within both the low-energy and moderate-energy rip current regimes. To date, our laboratory experiment provides the first extensive quantitative rip current information during a full down-state sequence for a given wave condition.
ISSN: 0148-0227

hal-00602920
https://hal.archives-ouvertes.fr/hal-00602920
DOI : 10.1029/2010JC006343

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
This paper describes how to tackle new challenging coastal engineering problems related to beach erosion with a shape optimization approach. The method modifies the shape of the sea bottom in order to reduce beach erosion effects. Global optimization is shown to be necessary as the related functionals have several local minima. We describe the physical model used, the proposed protection devices against beach erosion and real case applications.
ISSN: 0029-5981

hal-00411912
https://hal.archives-ouvertes.fr/hal-00411912
DOI : 10.1002/nme.2209

Éditeur(s) : Paris : Didier et Cie
Siècle(s) traité(s) : 18
Droits : Domaine public
Provenance : Collectivité territoriale de Martinique. Bibliothèque Schoelcher
Permalien : http://www.manioc.org/patrimon/SCH13237
SCH13237

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Forecasting of sea-state characteristics, with warning time of a few hours, appears a necessity in Operational Oceanography. linking sophisticated marine monitoring systems with forecasting modeling tools. In this paper, instead of using conventional numerical models, a Takagi-Sugeno-rule-based Fuzzy Inference System (FIS) was developed aiming at forecasting wave parameters based on the wind speed and direction, and the lagged-wave characteristics. Initial and final antecedent fuzzy membership functions were identified using the subtractive clustering method. The model was applied on the wind and wave dataset recorded in years 2000-2006 by an oceanographic buoy deployed in the Aegean Sea. The model showed perfect fit for the training period (2000-2005; 12,274 data points), and expanded its hindcasting ability during 2006 (1044 data points), as the verification part of the series. Model results, for a lead time of 3 h, showed good agreement between the predicted and the observed significant wave height (RMSE=0.216) and zero-up-crossing period (RMSE=0.315). According to other model performance criteria, the fuzzy model slightly underpredicted both wave characteristics (the linear regression slope was 0.911 for wave height and 0.788 for wave period), and reduced its forecasting ability at higher prediction intervals (+6 to + 12 h). Overall, model results illustrated that the developed FIS could serve as a valuable tool for the operational prediction of wave characteristics in Northern Aegean Sea, through the utilization of the POSEIDON network.
ISSN: 0029-8018

hal-00456020
https://hal.archives-ouvertes.fr/hal-00456020
DOI : 10.1016/j.oceaneng.2009.08.016

Éditeur(s) : Paris : Imprimerie royale
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Collectivité territoriale de Martinique. Bibliothèque Schoelcher
Permalien : http://www.manioc.org/patrimon/SCH13142
SCH13142

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The potential effects of the mineralogical composition of sediment on the degradation of oil buried on sandy beaches were investigated. Toward that purpose, a laboratory experiment was carried out with sandy sediment collected along NW Iberian Peninsula beaches, tar-balls from the Prestige oil spill (NW Spain) and seawater. The results indicate that the mineralogical composition is important for the physical appearance of the oil (tar-balls or oil coatings). This finding prompted a reassessment of the current sequence of degradation for buried oil based on compositional factors. Moreover, the halo development of the oil coatings might be enhanced by the carbonate concentration of the sand. These findings open new prospects for future monitoring and management programs for oiled sandy beaches.
ISSN: 0025-326X

hal-01122779
https://hal.archives-ouvertes.fr/hal-01122779
DOI : 10.1016/j.marpolbul.2014.06.040

Éditeur(s) : HAL CCSD World Scientific
Résumé : The present paper presents a laboratory experiment of rip current circulations over a moveable bed. The rip current characteristics over four distinct beach morphologies, exhibiting more or less developed nature-like bar-rip morphology,were investigated. For each video run, the same off shore shore-normal waves were generated by the wave maker with the same mean water level in order to study the sensitivity of the rip current characteristics as a function of the beach morphology only. In each case, a 1-hour video run was used to track a large number (~30) of drifters released within the surf zone. Image coordinates were then rectifie d to still water level Cartesian coordinates to compute drifter velocities, mean characteristics and surf zone rete ntion rates. Results show the presence of classic rip current patterns with counter-rotating cells and a relatively narrowoffshore-directed jet with, for three of the situations, a reasonably symmetric shape. Non-surprisingly, it was found that rip current intensity increases with increasing relative depth of the rip channel. The wave-driven circulations were strongly unstable. Computed standard deviation in fl ow intensity and direction provides high resolution information on the spatial variability of the rip current insta bilities with, for instance, highly-pulsating and weakly directionally variable offshore-directed flow in the rip channel. Conversely to what was previously hypothesized in the literature, there was hardly trace of vortices being shed offs hore and drifters exiting the surf zone compartment were not systematically caught by a pulsating jet. The cause for drifter exiting the semi-enclosed surf zone compartment remains, however, elusive and deserves further investigations. The computed surf zone retention rates (~90%) were of the order of those previously observed in the field, with no clear relationship with the mean rip current velocity or relative depth of the rip channel. Further video-runs will have to be analyzed to explore potential explanations
Proceedings of Coastal Dynamics 2009 Impacts of Human Activities on Dynamic Coastal Processes

ISBN : 978-981-4282-46
hal-00854534
https://hal.archives-ouvertes.fr/hal-00854534

Éditeur(s) : Paris : chez Pillet aîné
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Collectivité territoriale de Martinique. Bibliothèque Schoelcher
Permalien : http://www.manioc.org/patrimon/SCH13171
SCH13171

Éditeur(s) : Cayenne : Imprimerie du gouvernement
Résumé : Année 1883
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Collectivité territoriale de Guyane. Bibliothèque Alexandre-Franconie
Permalien : http://www.manioc.org/patrimon/FRA11264
FRA11264

Éditeur(s) : Cayenne : Imprimerie du gouvernement
Résumé : Année 1840
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Collectivité territoriale de Guyane. Bibliothèque Alexandre-Franconie
Permalien : http://www.manioc.org/patrimon/FRA11248
FRA11248

Éditeur(s) : Cayenne : Imprimerie du gouvernement
Résumé : Année 1845
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Collectivité territoriale de Guyane. Bibliothèque Alexandre-Franconie
Permalien : http://www.manioc.org/patrimon/FRA11230
FRA11230

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
The stratigraphy of the last deglaciation sequence is investigated in Lake Saint-Jean (Québec Province, Canada) based on 300 km of echo-sounder two dimensional seismic profiles. The sedimentary archive of this basin is documented from the Late Pleistocene Laurentidian ice-front recession to the present-day situation. Ten seismic units have been identified that reflect spatio-temporal variations in depositional processes characterizing different periods of the Saint-Jean basin evolution. During the postglacial marine flooding, a high deposition rate of mud settling, from proglacial glacimarine and then prodeltaic plumes in the Laflamme Gulf, produced an extensive, up to 50 m thick mud sheet draping the isostatically depressed marine basin floor. Subsequently, a closing of the water body due to glacio-isostatic rebound occurred at 8.5 cal. ka BP, drastically modifying the hydrodynamics. Hyperpycnal flows appeared because fresh lake water replaced dense marine water. River sediments were transferred towards the deeper part of the lake into river-related sediment drifts and confined lobes. The closing of the water body is also marked by the onset of a wind-driven internal circulation associating coastal hydrodynamics and bottom currents with sedimentary features including shoreface deposits, sediment drifts and a prograding shelf-type body. The fingerprints of a forced regression are well expressed by mouth-bar systems and by the shoreface-shelf system, the latter unexpected in such a lacustrine setting. In both cases, a regressive surface of lacustrine erosion (RSLE) has been identified, separating sandy mouth-bar from glaciomarine to prodeltaic muds, and sandy shoreface wedges from the heterolithic shelf-type body, respectively. The Lake Saint-Jean record is an example of a regressive succession driven by a glacio-isostatic rebound and showing the transition from late-glacial to post-glacial depositional systems.
ISSN: 0300-9483

hal-00984683
https://hal.archives-ouvertes.fr/hal-00984683
DOI : 10.1111/bor.12039

Éditeur(s) : Paris : Librairie Hachette
Siècle(s) traité(s) : 18
Droits : Domaine public
Provenance : Ville de Pointe-à-Pitre. Réseau des bibliothèques
Permalien : http://www.manioc.org/patrimon/PAP11043
PAP11043