Comparative biomarker responses in Japanese medaka (Oryzias latipes) exposed to benzo[a]pyrene and challenged with betanodavirus at three different life stages
It is now well documented that several contaminants can modulate the fish immune system, leading to disrupted host resistance against pathogens and increased incidence of disease. Since fish are usually co-exposed to chemicals and pathogens in the natural environment, analysis of the immunotoxic effects of pollutants is particularly relevant. The authorities in the European Union have recommended the development of toxicity assays on cell cultures and embryos, as an alternative to testing in vertebrates. This is why in our study, a fish immune challenge assay was developed for the early life stages of Japanese medaka to evaluate and compare the relevance of new biomarkers. Fish were exposed to benzo[a]pyrene (BaP), a model pollutant, for 8days at the embryonic stage, or for 48h at the larvae and juvenile stages, and fish were infected with betanodavirus by bath-challenge of 10TCID/mL. Biometric changes and induction of malformations were observed after embryonic exposure. DNA damage and induction of EROD activity were recorded at the end of all chemical exposures. Viral infection increased the mortality rate significantly and disturbed the behavior of fish after light stimulation. While BaP exposure increased swimming speed, betanodavirus infection slowed swimming activity. In larvae co-exposed to BaP and the virus, the viral titer in the whole body was higher than in fish infected only with the virus. This study highlighted the sensitivity and usefulness of the immune challenge assay on the early life stages of Japanese medaka to evaluate the toxic effects of pollutants.
(Science of the Total Environment. vol. 652, n° 0048-9697, pp. 964-976, 20/02/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ANSES, VIMEP, ANSES
Overtide generation by wind-induced waves in a tidal inlet of SW France
Quarter-diurnal tidal constituents are linked to tidal asymmetries and play a role in the morphodynamic evolution of inlets, estuaries and lagoons. A two-year non-continuous dataset of current velocities and waves was used to improve understanding on the generation of quarter-diurnal harmonics. Data analysis provides evidence for the generation of quarter-diurnal harmonics by wind-induced waves. Data were collected at the entrance to the Arcachon Lagoon, a mixed-energy tidal inlet in Southwest France. Temporal variability of the quarter-diurnal tidal current was identified through wavelet analysis of the main velocity component (alongshore velocity). Quarter-diurnal velocity amplitudes, bottom and wave stresses, and significant wave height suggested a linkage between quarter-diurnal amplification and wave action. Both significant wave height and wave stress were coherent with quarter-diurnal current amplitudes at synoptic frequencies, most markedly in winter months of both years observed. These coherences corroborated the hypothesis that wind-induced waves enhance bottom stresses that can generate and augment quarter-diurnal currents in this region.
(Continental Shelf Research. vol. 174, n° 0278-4343, pp. 66-75, 15/02/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Interactive effects of climate and topography on soil salinity and vegetation zonation in North‐African continental saline depressions
Questions: Complex distal factors such as climate and topography can interact to drive direct proximal ecological gradients and vegetation zonation in geographical and ecological space, in particular salinity and soil moisture in arid climates. We pose the following questions: (a) Does increasing climate aridity alter direct water and salinity gradients along topography gradients in saline depressions in arid climates? (b) Do these effects of increasing climate aridity in turn alter vegetation life-form zonation? (c) Does increasing climate aridity alter community composition along the zonation? Study site: Continental saline depressions of the Mediterranean arid climate of central and southern Tunisia. Methods: We sampled vegetation structure, diversity, and composition and environmental variables at five positions along the topography gradient of continental saline depressions in wet and dry conditions. Results: Climate aridity altered salinity gradients and vegetation structure but not diversity and community composition. Salinity increased with increasing aridity at the lowest positions of the depressions but decreased with increasing aridity at their highest positions. Total vegetation cover and relative abundance of therophytes decreased, whereas relative abundance of chamaephytes increased with increasing climate aridity at the upper habitats. Conclusions: Ecological factors acting at a regional scale can alter the spatial variation of other ecological factors acting at smaller spatial scales, ultimately explaining vegetation zonation in continental saline depressions. Salinity collapses with increasing aridity.
(Journal of Vegetation Science. vol. 30, n° 1100-9233, pp. 312-321, 15/02/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
A dual nanosecond-pulsed laser setup for nanocomposite synthesis—Ag nanoparticles in Al 2 O 3 /VO 2 matrix
(Journal of Applied Physics. vol. 125, n° 0021-8979, pp. 054301, 07/02/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IRCER, IPAM, UNILIM, INC-CNRS, CNRS, IRCER-AXE2, IRCER, IPAM, UNILIM, INC-CNRS, CNRS
Two-dimensional ammonium distribution in sediment pore waters using a new colorimetric diffusive equilibration in thin-film technique
This study presents a new gel based technique to describe the pore water ammonium distribution through the sediment-water interface in two dimensions at a millimeter scale. The technique is an adaptation of the classical colorimetric method based on the Berthelot's reaction. After the thin film of the gel probe was equilibrated by diffusion either in standard solutions or in pore waters, a colorimetric reagent gel was set on the gel probe, allowing development of the characteristic green color. A flatbed scanner and subsequent densitometry image analysis allowed to determine the concentration distribution of ammonium. The gel probe was tested in the laboratory for two media, deionized water and seawater, within the range 0e3000 mM in NH 4 þ. Detection limit is about 20 mM and accuracy about ±25 mM. The field validation was realized in a tidal mudflat of the French Atlantic coast by comparison with conventional pore water extraction and colorimetric analysis. The large range of concentrations and its applicability in continental and marine sediments suggest a wide range of applications of the technique for a reasonable cost.
(Water Research X. vol. 2, n° 2589-9147, pp. 100023, 01/02/2019)
BIAF, UA, IPGP, INSU - CNRS, UPD7, UR, IPG Paris, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Microfluidic technology for plankton research
Plankton produces numerous chemical compounds used in cosmetics and functional foods. They also play a key role in the carbon budget on the Earth. In a context of global change, it becomes important to understand the physiological response of these microorganisms to changing environmental conditions. Their adaptations and the response to specific environmental conditions are often restricted to a few active cells or individuals in large populations. Using analytical capabilities at the subnanoliter scale, microfluidic technology has also demonstrated a high potential in biological assays. Here, we review recent advances in microfluidic technologies to overcome the current challenges in high content analysis both at population and the single cell level.
(Current Opinion in Biotechnology. vol. 55, n° 0958-1669, pp. 134-150, 01/02/2019)
CRPP, UB, INC-CNRS, CNRS, CRPP, INC-CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, MPIDS
Fate of antibiotics present in a primary sludge of WWTP during their co-composting with palm wastes
(Waste Management. vol. 84, n° 0956-053X, pp. 13-19, 01/02/2019)
ENSAT, INP-ENSAT, AgroToulouse, INP-AgroToulouse, Toulouse INP, Comue de Toulouse, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LMFE, UCA, A2E, Toulouse INP, Comue de Toulouse
Distinguishing intraplate from megathrust earthquakes using lacustrine turbidites
Subduction zone seismicity arises from megathrust, crustal, and intraslab earthquakes, and understanding the recurrence patterns of each type is crucial for hazard assessments. Lake sediments can record earthquakes from all three seismogenic sources. Here, we studied the turbidite record of Lo Encañado, an Andean lake located in central Chile. We show that Lo Encañado turbidites can be attributed to (1) subaquatic slope failure by earthquake shaking (coseismic phase), (2) floods or human impact, and (3) postseismic catchment response. All historical events with shaking intensities >VI (modified Mercalli intensity) have triggered coseismic turbidites, but only the intraplate earthquakes triggered subaerial slope failures followed by postseismic turbidites. We argue that this contrasting result is due to different spectra of seismic waves from these earthquake sources: higher-frequency accelerations from intraplate earthquakes are hardly attenuated in rocks around the lake, whereas lower-frequency accelerations from megathrust earthquakes are amplified in soft lake sediments. We tested our findings by comparing acceleration response spectra of recent and historical intraslab and megathrust earthquakes along a longitudinal profile. Results suggest that the location of Andean lakes is ideal to distinguish earthquake sources.
(Geology. vol. 47, n° 0091-7613, pp. 127-130, 01/02/2019)
RCMG, UGent, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Where has the pollution gone? A survey of organic contaminants in Ho Chi Minh city / Saigon River (Vietnam) bed sediments
A wide range of persistent organic chemicals, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), some insecticides, as well as polybrominated diphenyl ethers (PBDEs) and some perfluoroalkyl substances (PFASs) were analyzed in 17 bed sediments collected along the Saigon River and at adjacent canal mouths from upstream to downstream in Ho Chi Minh City (Vietnam). Concentrations were rather low for PAHs, as well as for legacy PCBs and dichloro-diphenyl-trichlorethane and metabolites (DDTs), or below detection limits for several PFASs and all PBDEs measured. Several insecticides (chlorpyrifos-ethyl, and the pyrethroids cypermethrin and λ-cyhalothrin) displayed rather high concentrations at a few sites within the city. There was no distinct upstream – downstream trend for PAHs, (DDTs) or PCBs. Although adjacent canal sediments tended to be more contaminated than Saigon River sediments, the differences were not significant. Emissions are almost certainly substantial for PAHs, and probably also for other contaminants such as PBDEs and some PFASs. During the dry season, contaminants are presumably stored in the city, either in canals or on urban surfaces. Heavy rainfall during the monsoon period carries away contaminated particle flows into the canals and then the Saigon River. The strong tidal influence in the river channel hinders the accumulation of contaminated particles. Contaminated deposits should accordingly be investigated further downstream in depositional environments, such as the mangrove.
(Chemosphere. vol. 217, n° 0045-6535, pp. 261-269, 01/02/2019)
IRSTEA, LEHNA, UCBL, ENTPE, CNRS, GéHCO, UT, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EPFL, HCMUS, CARE, HCMUT, VNU-HCM, IGE, IRD, Grenoble INP, INSU - CNRS, CNRS, UGA [2016-2019], Fédération OSUG
High-resolution foraminifer stable isotope record of MIS 19 at Montalbano Jonico, southern Italy: A window into Mediterranean climatic variability during a low-eccentricity interglacial
(Quaternary Science Reviews. vol. 205, n° 0277-3791, pp. 106-125, 01/02/2019)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS, LBP, CNRS, UNISTRA, Université de Haute-Alsace (UHA), CNRS, HNHP, MNHN, UPVD, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS