Non parametric regression estimator: application in valvometry
(28/05/2026)
LMBA, UBS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Comparaison d'estimateurs de régression non paramétriques : application en valvométrie,
(28/05/2026)
LMBA, UBS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Impact of cadmium on aquatic bird Cairina moschata
The impact on palmiped Cairina moschata of two levels of dietary cadmium (Cd) contamination (C1: 1 mg kg-1 and C10: 10 mg kg-1) was investigated on liver gene expression by real-time PCR. Genes involved in mitochondrial metabolism, in antioxidant defences, detoxification and in DNA damage repair were studied. Metallothionein (MT) protein levels and Cd bioaccumulation were also investigated in liver, kidneys and muscle. Male ducks were subjected to three periods of exposure: 10, 20 and 40 days. Cd was mainly bioaccumulated in kidneys first and in liver. The concentrations in liver and kidneys appeared to reach a stable level at 20 days of contamination even if the concentrations in muscle still increased. Cd triggered the enhancement of mitochon-drial metabolism, the establishment of antioxidant defences (superoxide dismutase Mn and Cu/Zn; catalase) and of DNA repair from 20 days of contamination. Discrepancies were observed in liver between MT protein levels and MT gene up-regulation. MT gene expression appeared to be a late hour biomarker.
(BioMetals. vol. 22, n° 0966-0844, pp. 843-853, 28/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IPREM, UPPA, INC-CNRS, CNRS, UPPA
Consequences of a recent flood event on the biogeochemistry of the Rhône Delta
(28/05/2026)
EDF R&D STEP, EDF R&D, EDF [E.D.F.], EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPGN, UN, CNRS, IPGP, INSU - CNRS, UPD7, UR, IPG Paris, CNRS
Etude expérimentale de la célérité des vagues en zone de surf
L'estimation de la célérité des vagues en zone de surf est une étape essentielle dans la modélisation de la circulation littorale. Nous présentons une étude de ce paramètre basée sur les données de la campagne de mesure internationale ECORS 2008. En particulier, nous analysons, pour des houles très energétiques, l'influence des non-linéarités et évaluons plusieurs modèles prédictifs de célérité. Enfin, nous discutons l'influence des pulsations très basse-fréquence de la circulation sur la célérité.
(28/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Evidence for obliquity forcing of glacial Termination II
Variations in the intensity of high-latitude Northern Hemisphere summer insolation, driven largely by precession of the equinoxes, are widely thought to control the timing of Late Pleistocene glacial terminations. However, recently it has been suggested that changes in Earth's obliquity may be a more important mechanism. We present a new speleothem-based North Atlantic marine chronology that shows that the penultimate glacial termination (Termination II) commenced 141,000 T 2500 years before the present, too early to be explained by Northern Hemisphere summer insolation but consistent with changes in Earth's obliquity. Our record reveals that Terminations I and II are separated by three obliquity cycles and that they started at near-identical obliquity phases.
(Science, n° 0036-8075, pp. 1527-1531, 28/05/2026)
SUERC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, PACEA, UB, CNRS, AWI
Spatial heterogeneity in the food web of a heavily modified Mediterranean coastal lagoon: stable isotope evidence
We investigated the food web structure of the Salses-Leucate Lagoon (northwestern Mediterranean) through delta C-13 and delta N-15 analysis of its benthic macrofauna and potential food sources. This lagoon was heavily human-modified during the 1970s, allowing permanent exchange with the open sea and an increase in salinity from that time. As a result, it exhibits a much less marked salinity gradient than the neighbouring lagoon ecosystems, which Suggests a priori that its food web structure is more homogeneous. In this environmental context, we assessed spatial variability in the isotopic composition of non-vagrant macrofauna in Salses-Leucate in relation to degree of connection with the open sea, anthropogenic inputs and the presence of oyster aquaculture. Overall, the main trophic pathway is based on suspended particulate organic matter and sedimented organic matter. However, there were marked spatial differences (at different scales) in both delta C-13 and delta N-15 values of macrofauna, which suggests an important feeding plasticity within each category of primary consumers at a small spatial scale. delta C-13 data showed that the contributions of the different food sources to the diet of primary consumers changed depending on distance from continental inputs, connection with the open sea and local primary producer coverage. Small-scale delta N-15 variability revealed a very localised influence of anthropogenic nitrogen output. Regarding the possible effect of aquaculture, the isotopic ratios of sediment and macrobenthos were not modified underneath the oyster lines with respect to the neighbouring area. Conversely, the isotopic signature of consumers living on the oyster lines contrasted with those living underneath. Therefore, our results suggest that a decoupling exists between the trophic pathways that occur in the water column and on the soft bottom of this shallow water ecosystem.
(Aquatic Biology. vol. 5, n° 1864-7782, pp. 167-179, 28/05/2026)
LEMAR, IRD, IFREMER, UBO EPE, CNRS, LOBB, OOB, UPMC, CNRS, UPMC, INSU - CNRS, CNRS, EFEB, AD2M, SBR, UPMC, CNRS, UPMC, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Dynamics of the turbidity maximum zone in a macrotidal estuary (the Gironde, France): Observations from field and MODIS satellite data
Over a 1-year period, field and satellite measurements of surface water turbidity were combined in order to study the dynamics of the turbidity maximum zone (TM) in a macrotidal estuary (the Gironde, France). Four fixed platforms equipped with turbidity sensors calibrated to give the suspended particulate matter (SPM) concentration provided continuous information in the upper estuary. Full resolution data recorded by the moderate resolution imaging spectroradiometer (MODIS) sensors onboard the Terra and Aqua satellite platforms provided information in the central and lower estuary twice a day (depending on cloud cover). Field data were used to validate a recently developed SPM quantification algorithm applied to the MODIS `surface reflectance' product. The algorithm is based on a relationship between the SPM concentration and a reflectance ratio of MODIS bands 2 (near-infrared) and 1 (red). Based on 62 and 75 match-ups identified in 2005 with MODIS Terra and Aqua data, the relative uncertainty of the algorithm applied to these sensors was found to be 22 and 18%, respectively. Field measurements showed the tidal variations of turbidity in the upper estuary, while monthly-averaged MODIS satellite data complemented by field data allowed observing the monthly movements of the TM in the whole estuary. The trapping of fine sediments occurred in the upper estuary during the period of low river flow. This resulted in the formation of a highly concentrated TM during a 4-month period. With increasing river flow, the TM moved rapidly to the central estuary. A part of the TM detached, moved progressively in the lower estuary and was finally either massively exported to the ocean during peak floods or temporary trapped (settled) on intertidal mudflats. The massive export to the ocean was apparently the result of combined favorable environmental conditions: presence of fluid mud near the mouth, high river flow, high tides and limited wind speeds. The mean SPM concentration within surface waters of the whole estuary showed strong seasonal variations but remained almost unchanged on a 1-year-basis. These observations suggest that the masses of suspended sediments exported toward the ocean and supplied by the rivers were almost equivalent during the year investigated (2005). Results show the usefulness of information extracted from combined field and current ocean color satellite data in order to monitor the transport of suspended particles in coastal and estuarine waters. (c) 2008 Elsevier Ltd. All rights reserved.
(Estuarine, Coastal and Shelf Science. vol. 81, n° 0272-7714, pp. 321-332, 28/05/2026)
LOV, INSU - CNRS, SU, CNRS, IMEV, INSU - CNRS, SU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOV, OOVM, UPMC, INSU - CNRS, CNRS, UPMC, INSU - CNRS, CNRS
Contrasting intrainterstadial climatic evolution between high and middle North Atlantic latitudes: A close-up of Greenland Interstadials 8 and 12
Three highly resolved pollen and sea surface temperature records from the Iberian margin (36-42°N) reveal the local evolution of vegetation and climate associated with the rapid climatic variability of marine isotope stage 3. The comparison of the climate at these midlatitudes with dD and d excess from Greenland ice cores shows that the north-south climatic gradient underwent strong variations during the long Greenland Interstadials (GIs) 8 and 12. After the Northern Hemispheric rapid warming at the Greenland Stadial (GS)-GI transition, the trend during the first part of the GI is a Greenland cooling and an Iberian warming. This increase of the North Atlantic climatic gradient led to moisture transportation to Greenland from midlatitudes (lightest d excess) and to a drying episode in Iberia. The subsequent temperature decrease in Greenland and Iberia associated with the precipitation increase in the latter region occurred when the major source of Greenland precipitation shifted to lower latitudes (d excess increase).
(Geochemistry, Geophysics, Geosystems. vol. 10, pp. n/a-n/a, 28/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GLACCIOS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, UB
Antarctic climate change and the environment
The Antarctic climate system varies on timescales from orbital, through millennial to sub-annual, and is closely coupled to other parts of the global climate system. We review these variations from the perspective of the geological and glaciological records and the recent historical period from which we have instrumental data (, the last 50 years). We consider their consequences for the biosphere, and show how the latest numerical models project changes into the future, taking into account human actions in the form of the release of greenhouse gases and chlorofluorocarbons into the atmosphere. In doing so, we provide an essential Southern Hemisphere companion to the Arctic Climate Impact Assessment.
(Antarctic Science. vol. 21, n° 0954-1020, pp. 541, 28/05/2026)
BAS, NERC, GSFC, CNR, AWI, SCAR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS