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| Registros recuperados: 26.605 | |
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| Reveillon, Damien; Abadie, Eric; Sechet, Veronique; Masseret, Estelle; Hess, Philipp; Amzil, Zouher. |
| The neurotoxin BMAA (β-N-methylamino-l-alanine) and its isomer DAB (2,4-diaminobutyric acid) have been detected in seafood worldwide, including in Thau lagoon (French Mediterranean Sea). A cluster of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease associated with BMAA, has also been observed in this region. Mussels, periphyton (i.e. biofilms attached to mussels) and plankton were sampled between July 2013 and October 2014, and analyzed using HILIC-MS/MS. BMAA, DAB and AEG (N-(2-aminoethyl)glycine) were found in almost all the samples of the lagoon. BMAA and DAB were present at 0.58 and 0.83, 2.6 and 3.3, 4.0 and 7.2 μg g−1 dry weight in plankton collected with nets, periphyton and mussels, respectively. Synechococcus sp., Ostreococcus... |
| Tipo: Text |
Palavras-chave: BMAA; Diatoms; Chaetoceros sp.; Seston; Mytilus galloprovincialis; HILIC-MS/MS. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00275/38607/37192.pdf |
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| Sutton, Jill N.; Liu, Yi-wei; Ries, Justin B.; Guillermic, Maxence; Ponzevera, Emmanuel; Eagle, Robert A.. |
| The boron isotope composition (δ11B) of marine biogenic carbonates has been predominantly studied as a proxy for monitoring past changes in seawater pH and carbonate chemistry. However, a number of assumptions regarding chemical kinetics and thermodynamic isotope exchange reactions are required to derive seawater pH from δ11B biogenic carbonates. It is also probable that δ11B of biogenic carbonate reflects seawater pH at the organism's site of calcification, which may or may not reflect seawater pH. Here, we report the development of methodology for measuring the δ11B of biogenic carbonate samples at the multi-collector inductively coupled mass spectrometry facility at Ifremer (Plouzané, France) and the evaluation of δ11BCaCO3 in a diverse range of marine... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00430/54152/55481.pdf |
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| Campos, Marilia C.; Chiessi, Cristiano M.; Voigt, Ines; Piola, Alberto R.; Kuhnert, Henning; Mulitza, Stefan. |
| Abrupt millennial-scale climate change events of the last deglaciation (i.e. Heinrich Stadial 1 and the Younger Dryas) were accompanied by marked increases in atmospheric CO2 (CO2atm) and decreases in its stable carbon isotopic ratios (delta C-13), i.e. delta(CO2atm)-C-13, presumably due to out-gassing from the ocean. However, information on the preceding Heinrich Stadials during the last glacial period is scarce. Here we present delta C-13 records from two species of planktonic foraminifera from the western South Atlantic that reveal major decreases (up to 1%) during Heinrich Stadials 3 and 2. These delta C-13 decreases are most likely related to millennial-scale periods of weakening of the Atlantic meridional overturning circulation and the consequent... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53162/55294.pdf |
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| Djeghri, Nicolas; Stibor, Herwig; Lebeau, Oanez; Pondaven, Philippe. |
| Some jellyfish host zooxanthellae in their tissues (mostly from the family Symbiodiniaceae; Dinophyceae) and supplement their heterotrophic nutrition with their symbiont's photosynthates. The mixotrophy of zooxanthellate jellyfishes (as holobionts) renders the study of their nutrition, growth, and population dynamics complicated. Here, we used an experimental approach to assess how carbon and nitrogen stable isotopes (δ13C and δ15N) as well as the elemental composition (C:N ratios) of zooxanthellate jellyfishes are affected by variations in nutrition sources: i. e. predation (heterotrophic) versus photosynthesis (autotrophic). Our laboratory experiment, conducted on the zooxanthellate jellyfish Cassiopea sp. medusae (including symbionts) in the presence or... |
| Tipo: Text |
Palavras-chave: Stable isotopes; C:N ratios; Photosymbiosis; Mixotrophy; Scyphozoa; Zooxanthellae. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00591/70348/68448.pdf |
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| Riera, Pascal. |
| This study examined the delta(15)N of suspended and sedimented particulate organic matter, primary sources of organic matter and benthic invertebrates along an estuarine gradient in Marennes-Oleron Bay, France. Particular emphasis was given to the use of delta(15)N as a tracer of the origin of organic matter and as a means of determining the benthic food web structure in estuarine environments. delta(15)N values indicated that there was direct utilisation of benthic diatoms as a food source by oyster Crassostrea gigas near intertidal mudflats but suggested trophic mediation between terrestrial detritus and oysters in the upper estuarine reaches. delta(15)N data showed that the trophic position of oysters may vary in the estuarine bay. The delta(15)N values... |
| Tipo: Text |
Palavras-chave: Nitrogen isotope ratio; Particulate organic matter; Crassostrea gigas; Benthic food web; Estuary; Marennes-Oleron Bay. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00448/55926/57786.pdf |
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| Registros recuperados: 26.605 | |
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