A fault detection method for an automatic detection of spawning in oysters
Using measurements of valve activity (i.e. the distance between the two valves) in populations of bivalves under natural environmental condition (16 oysters in the Bay of Arcachon, France, in 2007, 2013 and 2014), an algorithm for an automatic detection of the spawning period of oysters is proposed in this paper. Spawning observations are important in aquaculture and biological studies, and until now, such a detection is done through visual analysis by an expert. The algorithm is based on the fault detection approach and it works through the estimation of velocity of valve movement activity, that can be obtained by calculating the time derivative of the valve distance. A summarized description of the methods used for the derivative estimation is provided, followed by the associated signal processing and decision making algorithm to determine spawning from the velocity signal. A protection from false spawning detection is also considered by analyzing the simultaneity in spawning. Through this study, it is shown that spawning in a population of oysters living in their natural habitat (i.e. in the sea) can be automatically detected without any human expertise saving time and resources. The fault detection method presented in the paper can also be used to detect complex oscillatory behavior which is of interest to control engineering community.
(IEEE Transactions on Control Systems Technology. vol. 24, n° 1063-6536, pp. 1140--1147, 01/03/2016)
NON-A, Inria, CRIStAL, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Role of macrofauna on benthic oxygen consumption in sandy sediments of a high-energy tidal beach
Sandy beaches exposed to tide and waves are characterized by low abundance and diversity of benthic macrofauna, because of high-energy conditions. This is the reason why there are few studies on benthic communities living in such highly dynamic environments. It has been shown recently that tidal sandy beaches may act as biogeochemical reactors. Marine organic matter that is supplied in the sand during each flood tide is efficiently mineralized through aerobic respiration. In order to quantify the role of macrofauna in the whole beach benthic respiration, we studied the macrofauna and the pore water oxygen content of an exposed sandy beach (Truc Vert, SW of France) during four seasons in 2011. The results showed that macrofauna was characterised by a low number of species of specialized organisms such as the crustaceans Eurydice naylori and Gastrosaccus spp. and the polychaetes Ophelia bicornis and Scolelepis squamata. The distribution and abundance of macrofauna were clearly affected by exposure degree and emersion time. The combined monitoring of benthic macrofauna and pore waters chemistry allowed us to estimate (1) the macrofauna oxygen uptake, calculated with a standard allometric relationship using biomass data, and (2) the total benthic oxygen uptake, calculated from the oxygen deficit measured in pore waters. This revealed that benthic macrofauna respiration represented a variable but low (<10%) contribution to the total benthic oxygen consumption This suggests that oxygen was mainly consumed by microbial respiration.
(Continental Shelf Research, n° 0278-4343, 01/03/2016)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Untangling the complex origin of turbidite activity on the Calabrian Arc (Ionian Sea) over the last 60ka
The Ionian Sea, due to the presence of two accretionary prisms, the Calabrian Arc and the Mediterranean Ridge, associated with the subduction of the Nubia plate and the Eurasia plate, is the witness of large and catastrophic turbidite events. These events are associated with high magnitude earthquakes and tsunamis. They lead an important gravity-driven sedimentary deposit in the Ionian basin. In this study, we analysed turbidite deposits in order to establish a calendar of the palaeoseismicity and volcaniclastic events from Etna on the Calabrian Arc. Two gravity cores collected in a slope basin on the Calabrian Arc and in the Ionian abyssal plain record more than two hundred turbidites over the last 60,000 years. These turbidites were dated with a multi-proxy approach: radiometric dating, tephrochronology and sapropels. The origin of the turbidites was studied with a sedimentary approach: grain-size, lithology, thin section, and geochemistry of volcanic glass. The results suggest that three triggers are responsible for the deposits of turbidites. There are siliciclastic turbidites triggered by earthquakes and tsunamis waves, and volcaniclastic turbidites triggered by the Etna volcano eruptions or flank collapses. Co-seismic turbidites present different recurrence times depending on the location of the core. On the Calabrian Arc, recurrence times vary between 450 and 1000 years according to the periods in time. On the abyssal plain, recurrence times are shorter and more regular: around every 240 years.
(Marine Geology. vol. 373, n° 0025-3227, pp. 11-25, 01/03/2016)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SHOM, LMV, UBP, INSU - CNRS, UJM, UJM EPE, CNRS, IUEM, IRD, INSU - CNRS, UBO EPE, CNRS
Psychotropic drugs in mixture alter swimming behaviour of Japanese medaka (Oryzias latipes) larvae above environmental concentrations
Psychiatric pharmaceuticals, such as anxiolytics, sedatives, hypnotics and antidepressors, are among the most prescribed active substances in the world. The occurrence of these compounds in the environment, as well as the adverse effects they can have on non-target organisms, justifies the growing concern about these emerging environmental pollutants. This study aims to analyse the effects of six psychotropic drugs, valproate, cyamemazine, citalopram, sertraline, fluoxetine and oxazepam, on the survival and locomotion of Japanese medaka Oryzias latipes larvae. Newly hatched Japanese medaka were exposed to individual compounds for 72 h, at concentrations ranging from 10 μg L−1 to 10 mg L−1. Lethal concentrations 50 % (LC50) were estimated at 840, 841 and 9,136 μg L−1 for fluoxetine, sertraline and citalopram, respectively, while other compounds did not induce any significant increase in mortality. Analysis of the swimming behaviour of larvae, including total distance moved, mobility and location, provided an estimated lowest observed effect concentration (LOEC) of 10 μg L−1 for citalopram and oxazepam, 12.2 μg L−1 for cyamemazine, 100 μg L−1 for fluoxetine, 1,000 μg L−1 for sertraline and >10,000 μg L−1 for valproate. Realistic environmental mixture of the six psychotropic compounds induced disruption of larval locomotor behaviour at concentrations about 10- to 100-fold greater than environmental concentrations.
(Environmental Science and Pollution Research. vol. 23, n° 0944-1344, pp. 4964-4977, 01/03/2016)
LCE, CNRS, UMLP, UBFC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, INUC, Comue de Toulouse, GEODE, UT2J, Comue de Toulouse, CNRS
Pre-hatching fluoxetine-induced neurochemical, neurodevelopmental, and immunological changes in newly hatched cuttlefish
Embryonic and early postembryonic development of the cuttlefish Sepia officinalis (a cephalopod mollusk) occurs in coastal waters, an environment subject to considerable pressure from xenobiotic pollutants such as pharmaceutical residues. Given the role of serotonin in brain development and its interaction with neurodevelopmental functions, this study focused on fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI, antidepressant). The goal was to determine the effects of subchronic waterborne FLX exposure (1 and 10 mu g L-1) during the last 15 days of embryonic development on neurochemical, neurodevelopmental, behavioral, and immunological endpoints at hatching. Our results showed for the first time that organic contaminants, such as FLX, could pass through the eggshell during embryonic development, leading to a substantial accumulation of this molecule in hatchlings. We also found that FLX embryonic exposure (1 and 10 mu g L-1) (1) modulated dopaminergic but not serotonergic neurotransmission, (2) decreased cell proliferation in key brain structures for cognitive and visual processing, (3) did not induce a conspicuous change in camouflage quality, and (4) decreased lysozyme activity. In the long term, these alterations observed during a critical period of development may impair complex behaviors of the juvenile cuttlefish and thus lead to a decrease in their survival. Finally, we suggest a different mode of action by FLX between vertebrate and non-vertebrate species and raise questions regarding the vulnerability of early life stages of cuttlefish to the pharmaceutical contamination found in coastal waters.
(Environmental Science and Pollution Research. vol. 23, n° 0944-1344, pp. 5030--5045, 01/03/2016)
GMPc, UNICAEN, NU, BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
First light of the VLT planet finder SPHERE II. The physical properties and the architecture of the young systems PZ Telescopii and HD 1160 revisited
Context. The young systems PZ Tel and HD 1160, hosting known low-mass companions, were observed during the commissioning of the new planet finder of the Very Large Telescope (VLT) SPHERE with several imaging and spectroscopic modes. Aims. We aim to refine the physical properties and architecture of both systems. Methods. We use SPHERE commissioning data and dedicated Rapid Eye Mount (REM) observations, as well as literature and unpublished data from VLT/SINFONI, VLT/NaCo, Gemini/NICI, and Keck/NIRC2. Results. We derive new photometry and confirm the short-term (P = 0.94 d) photometric variability of the star PZ Tel A with values of 0.14 and 0.06 mag at optical and near-infrared wavelengths, respectively. We note from the comparison to literature data spanning 38 yr that the star also exhibits a long-term variability trend with a brightening of similar to 0.25 mag. The 0.63-3.8 mu m spectral energy distribution of PZ Tel B (separation similar to 25 AU) allows us to revise its physical characteristics: spectral type M7 +/- 1, T-eff = 2700 +/- 100 K, log(g) \textless 4.5 dex, luminosity log(L/L-circle dot) = 2.51 +/- 0.10 dex, and mass 38 72 M-J from “hot-start” evolutionary models combining the ranges of the temperature and luminosity estimates. The 1-3.8 mu m SED of HD 1160 B (similar to 85 au) suggests a massive brown dwarf or a low-mass star with spectral type M6.0+1.00.5, T-eff = 3000 +/- 100 K, subsolar metallicity [M/H] = -0.5-0.0 dex, luminosity log(L/L-circle dot) = 2.81 +/- 0.10 dex, and mass 39 166 MJ. The physical properties derived for HD 1160 C (similar to 560 au) from KsL' -band photometry are consistent with the discovery study. The orbital study of PZ Tel B confirms its deceleration and the high eccentricity of its orbit (e \textgreater 0.66). For eccentricities below 0.9, the inclination, longitude of the ascending node, and time of periastron passage are well constrained. In particular, both star and companion inclinations are compatible with a system seen edge-on. Based on “hot-start” evolutionary models, we reject other brown dwarf candidates outside 0.25 `' for both systems, and giant planet companions outside 0.5 `' that are more massive than 3 MJ for the PZ Tel system. We also show that K1-K2 color can be used along with YJH low-resolution spectra to identify young L-type companions, provided high photometric accuracy (\textless= 0.05 mag) is achieved. Conclusions. SPHERE opens new horizons in the study of young brown dwarfs and giant exoplanets using direct imaging thanks to high-contrast imaging capabilities at optical (0.5-0.9 mu m) and near-infrared (0.95-2.3 mu m) wavelengths, as well as high signal-to-noise spectroscopy in the near-infrared domain (0.95-2.3 mu m) from low resolutions (R similar to 30 50) to medium resolutions (R similar to 350).
(Astronomy & Astrophysics - A&A. vol. 587, n° 0004-6361, 01/03/2016)
OAPD, INAF, IPAG, INSU - CNRS, CNES, CNRS, OSUG, Grenoble INP, INSU - CNRS, IRSTEA, USMB [Université de Savoie] [Université de Chambéry], CNRS, UGA [2016-2019], LAM, AMU, INSU - CNRS, CNES, CNRS, ESO, ESO, OACT, INAF, LESIA, UPMC, INSU - CNRS, CNRS, PSL, UPD7, CNRS, MPIA, ETH Zürich, UNIGE, UDP, DAS, UCHILE, AI PANNEKOEK, UvA, TUM, CRAL, ENS de Lyon, UCBL, INSU - CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CALTECH, CFHT, INSU - CNRS, NRC, CNRS, UH, GSFC, MONARIS, UPMC, INC-CNRS, CNRS, ObsGE, UNIGE, LAGRANGE, UNS, INSU - CNRS, UniCA, CNRS, UniCA, ESRF, CREATIS, UCBL, INSA Lyon, INSA, UJM, UJM EPE, INSERM, CNRS
In situ spawning in a marine broadcast spawner, the Pacific oyster Crassostrea gigas: Timing and environmental triggers
The precise environmental conditions under which broadcast spawners spawn in the field remain largely unknown. We investigated this issue in the oyster Crassostrea gigas using three different methods at different time scales in two traditional oyster farming areas of the French Atlantic Coast, the Bay of Arcachon and Marennes-Oléron. We directly recorded spawning at high temporal resolution using high-frequency non-invasive (HFNI) valvometry from 2007–2014 and measured the dry mass and oyster larvae abundance in 2008 and 2009. We analyzed a 29-yr series of oyster D-larvae numbers in the Bay of Arcachon (1982–2010). By combining these three approaches, we demonstrated that during the summer months at both sites, spawning in C. gigas occurs in the morning or during the evening, essentially at high tide of perigean spring tides, independent of the positions of these oysters, above or below the lowest water level. We characterized the associated water currents at the spawning location in the Bay of Arcachon and observed that spawning systematically occurs during the early phase of a water current peak, at the beginning of ebbing. We propose that this water current peak acts as a final trigger for spawning. These results have ecological consequences associated with gamete encounters and the dispersal of fertilized eggs (zygotes).
(Limnology and Oceanography. vol. 61, n° 0024-3590, pp. 635-647, 01/03/2016)
IFREMER, LEMAR, IRD, IFREMER, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Sub-chronic exposure to fluoxetine in juvenile oysters (Crassostrea gigas): uptake and biological effects
The bioconcentration potential of fluoxetine (FLX) and its biological effects were investigated in juvenile Pacific oyster exposed for 28 days to environmentally relevant concentrations of FLX (1 ng L−1, 100 ng L−1 and up to 10 μg L−1). FLX bioaccumulated in oyster flesh resulting in 28-day bioconcentration factors greater than 2,000 and 10,000 by referring to wet and dry weights, respectively. Nevertheless, FLX did not induce oyster mortality, delayed gametogenesis, or lead to adverse histopathological alterations. At the two highest concentrations, despite non-optimal trophic conditions, FLX stimulated shell growth but only in a transient manner, suggesting a role of serotonin in the regulation of feeding and metabolism in bivalves. Those high concentrations seemed to drive bell-shaped responses of catalase and glutathione S-transferase activities throughout the exposure period, which may indicate the activation of antioxidant enzyme synthesis and then an enhanced catabolic rate or direct inhibition of those enzymes. However, no clear oxidative stress was detected because no strong differences in thiobarbituric acid-reactive substance (TBARS) content (i.e. lipid peroxidation) were observed between oyster groups, suggesting that cellular defence mechanisms were effective. These results demonstrate the importance of considering additional biomarkers of oxidative stress to obtain a comprehensive overview of the FLX-induced changes in marine bivalves exposed under realistic conditions. Considering the battery of biomarkers used, FLX appears to induce little or no effects on oyster physiology even at a concentration of 10 μg L−1. These results do not confirm the lowest observed effect concentration (LOEC) values reported by some authors in other mollusc species.
(Environmental Science and Pollution Research. vol. 23, n° 0944-1344, pp. 5002-5018, 01/03/2016)
GMPc, UNICAEN, NU, BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, LEFE, INEE-CNRS, CNRS, UT3, Comue de Toulouse, CNRS, Toulouse INP, Comue de Toulouse, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPTC, UB, CNRS
Proteomic changes in Corbicula fluminea exposed to wastewater from a psychiatric hospital
The increase use of pharmaceutical compounds in veterinary practice and human population results in the ubiquitous presence of these compounds in aquatic ecosystems. Because pharmaceuticals are highly bioactive, there is concern about their toxicological effects in aquatic organisms. Therefore, the aim of this study was to assess the effects of an effluent from a psychiatric hospital (containing a complex mixture of 25 pharmaceutical compounds from eleven therapeutic classes) on the freshwater clam Corbicula fluminea using a proteomic approach. The exposure of C. fluminea to this complex effluent containing anxiolytics, analgesics, lipid regulators, beta blockers, antidepressants, antiepileptics, antihistamines, antihypertensives, antiplatelets and antiarrhythmics induced protein changes after 1 day of exposure in clam gills and digestive gland more evident in the digestive gland. These changes included increase in the abundance of proteins associated with structural (actin and tubulin), cellular functions (calreticulin, proliferating cell nuclear antigen (PCNA), T complex protein 1 (TCP1)) and metabolism (aldehyde dehydrogenase (ALDH), alcohol dehydrogenase, 6 phosphogluconate dehydrogenase). Results from this study indicate that calreticulin, PCNA, ALDH and alcohol dehydrogenase in the digestive gland and T complex protein 1 (TCP1)) and 6 phosphogluconate dehydrogenase in the gills represent useful biomarkers for the ecotoxicological characterization of psychiatric hospital effluents in this species.
(Environmental Science and Pollution Research. vol. 23, n° 0944-1344, pp. 5046-5055, 01/03/2016)
CIMA, UAlg, LECA, USMB [Université de Savoie] [Université de Chambéry], CNRS, UGA [2016-2019], IRIB, UNIROUEN, NU, INSERM, CNRS, HeRacLeS, UNIROUEN, NU, IRIB, UNIROUEN, INSERM, CNRS, INSERM, INC-CNRS, CNRS, BTSB, INUC, Comue de Toulouse, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GEODE, UT2J, Comue de Toulouse, CNRS, INUC, Comue de Toulouse
Differences between mono-generic and mixed diatom silicon isotope compositions trace present and past nutrient utilisation off Peru
In this study we combine for the first time silicon (Si) isotope compositions of small mixed diatom species (d 30 Si bSiO2) and of large handpicked mono-generic (i.e. genus = Coscinodiscus) diatom samples (d 30 Si Coscino) with diatom assemblages extracted from marine sediments in the Peruvian upwelling region in order to constrain present and past silicate utilisation. The extension of a previous core-top data set from the Peruvian shelf demonstrates that d 30 Si Coscino values record near-complete Si utilisation, as these are similar to the isotopic composition of the subsurface source waters feeding the upwelling. In contrast, the d 30 Si bSiO2 of small mixed diatom species increase southward along the shelf as well as towards the shore. We attribute highest d 30 Si bSiO2 values partly to transient iron limitation but primarily to the gradual increase of Si isotope frac-tionation within the seasonal diatom succession, which are mainly recorded by small diatom species during intense bloom events. In contrast, lower d 30 Si bSiO2 values are related to initial Si isotope utilisation during periods of weak upwelling, when low Si(OH) 4 concentrations do not permit intense blooms and small diatom species record substantially lower d 30 Si signatures. As such, we propose that the intensity of the upwelling can be deduced from the offset between d 30 Si bSiO2 and d 30 Si Coscino (D 30 Si coscino-bSiO2), which is low for strong upwelling conditions and high for prevailing weak upwelling. We apply the information extracted from surface sediments to generate a record of the present-day main upwelling region covering the past 17,700 years and find that this location has also been characterized by a persistent offset (D 30 Si coscino-bSiO2). By comparison with the diatom assemblages we show that the coastal upwelling system changed markedly between weak and strong upwelling conditions. In addition, our model calculations to quantify species-specific Si isotope fractionation effects based on the diatom assemblages indicate an overall minor influence that cannot explain the high amplitude in the measured d 30 Si bSiO2 record.
(Geochimica et Cosmochimica Acta. vol. 177, n° 0016-7037, pp. 30-47, 01/03/2016)
GEOMAR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, RWTH Aachen, CAU