ENSO and interdecadal climate variability over the last century documented by geochemical records of two coral cores from the South West Pacific
The south west Pacific is affected by climatic phenomena such as ENSO (El Niño Southern Oscillation) or the PDO (Pacific Decadal Oscillation). Near-monthly resolution calibrations of Sr/Ca, U/Ca and d18Oc were made on corals taken from New Caledonia and Wallis Island. These geochemical variations could be linked to SST (sea surface temperature) and SSS (sea surface salinity) variations over the last two decades, itselves dependent on ENSO occurrences. On the other hand, near-half-yearly resolution over the last century smoothes seasonal and interannual climate signals, but emphasizes low frequency climate variability.
(Advances in Geosciences. vol. 6, n° 1680-7340, pp. 27, 09/01/2006)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, PALEOTROPIQUE
Modélisation du festonnage des barres sableuses d'avant-côte : application à la côte aquitaine, France
Modeling of crescentic pattern development of nearshore bars: Aquitanian Coast, France. Nearshore crescentic bars play key role in nearshore morphodynamics. These bars are observed all along the Aquitanian Coast, with a mean wavelength of about 700 m. A non-linear stability analysis is undertaken to simulate the development of crescentic patterns. Results show that self-organization mechanism can lead alone to the development of these alongshore rhythmic features. Simulated wavelengths are in agreement with observations on the Aquitanian Coast.
(Comptes Rendus. Géoscience. vol. 338, n° 1631-0713, pp. 795-801, 01/01/2006)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IMB, UB, Bordeaux INP, CNRS
cDNA cloning and gene expression of ribosomal S9 protein gene in the mollusk Corbicula fluminea: A new potential biomarker of metal contamination up-regulated by cadmium and repressed by zinc
Biological indicators can be used to assess polluted sites, but their success depends on their specificity. The aim of the present study was to identify a specific cadmium biomarker of the freshwater bivalve Corbicula fluminea. Differential display technique was used to identify new molecular indicators for cadmium exposure. Gene expression of C. fluminea transplanted into a cadmium- and zinc-contaminated river was compared to gene expression of bivalves from a reference site. One differentially expressed band was identified, and the entire cDNA sequence coding for the ribosomal protein S9 (rpS9) was cloned. The rpS9 gene expression was studied by real-time reverse transcription-polymerase chain reaction. After controlled cadmium (15 microg/L) and/or zinc (1 mg/L) laboratory contaminations of the bivalves, this gene was shown to be up-regulated by cadmium and down-regulated by zinc. A 48-d transplantation of animals into a polymetallic field contamination in the Lot river basin (Midi-Pyrénées region, France) showed that rpS9 gene regulation was correlated with the fluctuating cadmium and zinc water contents. To our knowledge, the existence of a gene that is up-regulated by cadmium and repressed by zinc is demonstrated here for the first time.
(Environmental Toxicology and Chemistry. vol. 25, n° 0730-7268, pp. 527, 01/01/2006)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Modélisation du courant sagittal induit par les vagues au-dessus des systèmes barre/baïne de la côte aquitaine (France)
Modelling of a rip current induced by waves over a ridge and runnel system on the Aquitanian Coast, France. The spectral wave driver SWAN is coupled with the time- and depth-averaged (2DH) coastal area model MORPHODYN. This coupled model is used to simulate the rip current induced by breaking waves over ridge and runnel systems on the French Aquitanian Coast. Simulations lead to a description of the rip current characteristics and the physical mechanisms leading to its formation. The rip current is controlled by the local bathymetry, the tide level and offshore wave conditions. The presence of this rip current is favoured by shore-normal incidence and long-period swells. During low-energy conditions, the maximum rip current velocity occurs at midtide. For higher energy conditions, the maximum rip velocity sweeps to high tide. The residual forcing notion enables to explain and to highlight this tidal modulation and the rip current formation mechanisms
(Comptes Rendus. Géoscience. vol. 338, n° 1631-0713, pp. 711-717, 01/01/2006)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
A surface complexation model for cadmium and lead adsorption onto diatom surface
This work is devoted to the physico-chemical study of cadmium and lead interaction with diatom–water interfaces for two marine planktonic (Thalassiosira weissflogii = TW, Skeletonema costatum = SC) and two freshwater periphytic species (Achnanthidium minutissimum = AMIN, Navicula minima = NMIN) by combining adsorption measurements with surface complexation modeling. Reversible adsorption experiments were performed at 20 °C after 3 h of exposure as a function of pH, metal concentration in solution, and ionic strength. While the shape of pH-dependent adsorption edge is similar among all four diatom species, the constant-pH adsorption isotherm and maximal binding capacities differ. These observations allowed us to construct a surface complexation model for cadmium and lead binding by diatom surfaces that postulates the constant capacitance of the electric double layer and considers Cd and Pb complexation with mainly carboxylic and, partially, silanol groups. Parameters of this model are in agreement with previous acid–base titration results and allow quantitative reproduction of all adsorption experiments.
(Journal of Geochemical Exploration. vol. 88, n° 0375-6742, pp. 110-113, 01/01/2006)
LMTG, UT3, Comue de Toulouse, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Eco-Cultural Niche Modeling: New Tools for Reconstructing the Geography and Ecology of Past Human Populations
Prehistoric human populations were influenced by climate change and resulting environmental variability and developed a wide variety of cultural mechanisms to deal with these conditions. In an effort to understand the inesfluence of environmental factors on prehistoric social and technical systems, there is a need to establish methods with which to model and evaluate the rules and driving forces behind these human-environment interactions. We describe a new set of analytical tools―an approach termed Eco-Cultural Niche Modeling (ECNM)―that can be used to address these issues and to test current hypotheses. This approach's modeling architectures are used to reconstruct past human systems in the Old and New Worlds, past natural systems within which they operated― namely geological, paleobiological and paleoenvironmental conditions―and also to develop informed hypotheses concerning the geographic spread, migration, and eco-cultural adaptations of prehistoric human populations. The ECNM approach has recently been developed and explored at two National Science Foundation- and European Science Foundation-funded workshops. We describe the goals and methods of ECNM, the results of the proof-of-concept projects, the analytical issues that remain unresolved, and the potential this approach has to offer the disciplines of paleoanthropology and archaeology.
(Paleoanthropology. vol. 2006, n° 1545-0031, pp. 68-83, 22/02/2026)
PACEA, UB, CNRS, KU, KU, ASU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UCL
Courants induits et dissipation de l'énergie des vagues sur les plages macrotidales de la mer d'Iroise
(22/02/2026)
LETG - Brest, LETG, UNICAEN, NU, UA, EPHE, PSL, UBO EPE, UR2, CNRS, IGARUN, UN, NU, UNIROUEN, NU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Cadmium transport in sediments by tubificid bioturbation: an assessment of model complexity.
(Geochimica et Cosmochimica Acta. vol. 71, n° 0016-7037, pp. 844 - 862, 22/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEH, UT3, Comue de Toulouse, CNRS
Liquefied vs Stratified Sedimentation Mobilization Processes: Insight from the South of the Barbados Accretionary Prism
(Tectonophysics. vol. 428, n° 0040-1951, pp. 33-47, 22/02/2026)
IFPEN, BRGM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LGCA, OSUG, UJF, Grenoble INP, INSU - CNRS, IRSTEA, USMB [Université de Savoie] [Université de Chambéry], CNRS, CNRS, GEOSCIENCES, PSL
A fourth-order compact finite volume scheme for fully nonlinear and weakly dispersive Boussinesq-type equations. Part I: Model development and analysis
A high‐order finite volume scheme is developed to numerically integrate a fully nonlinear and weakly dispersive set of Boussinesq‐type equations (the so‐called Serre equations) (J. Fluid Mech. 1987; 176:117–134; Surveys Geophys. 2004; 25(3–4):315–337). The choice of this discretization strategy is motivated by the fact that this particular set of equations is recasted in a convenient quasi‐conservative form. Cell face values are reconstructed using implicit compact schemes (J. Comput. Phys. 1999; 156:137–180; J. Comput. Phys. 2004; 198:535–566) and time integration is performed with the help of a four‐stage Runge–Kutta method. Numerical properties of the proposed scheme are investigated both, analytically using linear spectral analysis, and numerically for highly nonlinear cases. The numerical analysis indicates that the newly developed scheme has wider stability regions and better spectral resolution than most of the previously published numerical methods used to handle equivalent set of equations. Moreover, it was also noticed that the use of mixed‐order strategies to discretize convective and dispersive terms may result in an important overall reduction of the spectral resolution of the scheme. Additionally, there is some numerical evidence, which seems to indicate that the incorporation of a high‐order dispersion correction term as given by Madsen et al. (Coastal Eng. 1991; 15:371–388) may introduce instability in the system
(International Journal for Numerical Methods in Fluids. vol. 51, n° 0271-2091, pp. 1217-1253, 22/02/2026)
LEGI, UJF, Grenoble INP, CNRS, PUC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS