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Registros recuperados: 30 | |
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Soudant, Dominique. |
Le Dinophysis est une microalgue toxique à l’origine d’epidémies diarrhéiques. En dépit de nombreuses études, l’écologie et la biologie de ce genre phytoplanctonique restent mal connues. Afin de déterminer les conditions d’apparition de Dinophysis cf. acuminata sur le site d’Antifer (Normandie, France), des prélèvements d’eau de mer ont été effectués quasi-journellement pendant les périodes estivales des années 1987 à 1993. Les séries temporelles résultantes concernent la concentration de la microalgue et les facteurs chimiques, physiques et météorologiques. L’analyse de ces données à l’aide d’outils sta- tistiques classiques (e.g. régression) s’est avérée difficile (e.g. instabilité temporelle des résultats). Une caractéristique commune de ces méthodes... |
Tipo: Text |
Palavras-chave: Modélisation; Statistique; Dynamique; Séries temporelles; Bayésien; Dinophysis; Baie de Seine. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00015/12576/9446.pdf |
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Lassus, Patrick; Maggi, Pierre; Proniewski, F.; Truquet, Philippe; Bardouil, Michele. |
Since 1987 Antifer oil tanker terminal (Normandy, France) was weIl known, as a preferential area for summer highest blooms of Dinophysis cf acuminata, a toxic dinoflagellate. Three oceanographic cruises were made in August 1989, before, in the course of and after the seasonal max. of this species. Results obtained from these cruises (hydrological parameters and phytoplankton) as weIl as from a daily survey at a reference station in Antifer harbour, corrobora te the prevailing role of coastal up flowing of Seine estuarine waters, pushed to the coast by a dominant S - SW wind, on intensity and duration of Dinophysis bloom. Such observations are in agreement with those of Summer 1987 at reference station. |
Tipo: Text |
Palavras-chave: Antifer; Dinophysis; Hydrologie; Phytoplancton; Antifer; Dinophysis; Hydrology; Phytoplankton. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00138/24946/23039.pdf |
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Bardouil, Michele; Masselin, Pierre; Bohec, Madeleine. |
Laboratory assays have been performed, using mussels contamined with Dinophysis, in order to assess potential depurations kinetics. Mussels samples from Seine bay, Douarnenez bay and Vilaine bay have been tested . From these assays, which are to be performed in 1989; two main results are stressed : 1) when the toxicity level is near 0,5 MU/g of hepatopancreas*, depuration is undedectable during twelve days, 2) when the toxicity level exceeds 1 MU/g,depuration is important during the first eight days. *(quarantine level used by Japanese authorities) . |
Tipo: Text |
Palavras-chave: Moules; DSP; Dinophysis; Décontamination; Blue mussels; DSP; Dinophysis; Depuration. |
Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00430/54148/55479.pdf |
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Gaillard, Sylvain; Charrier, Aurelie; Malo, Florent; Carpentier, Liliane; Bougaran, Gael; Hégaret, Helene; Réveillon, Damien; Hess, Philipp; Séchet, Veronique. |
The cryptophyte Teleaulax amphioxeia is a source of plastids for the ciliate Mesodinium rubrum and both organisms are members of the trophic chain of several species of Dinophysis. It is important to better understand the ecology of organisms at the first trophic levels before assessing the impact of principal factors of global change on Dinophysis spp. Therefore, combined effects of temperature, irradiance and pH on growth rate, photosynthetic activity and pigment content of a temperate strain of T. amphioxeia were studied using a full factorial design (central composite design 23*) in 17 individually controlled bioreactors. The derived model predicted an optimal growth rate of T. amphioxeia at a light intensity of 400 µmol photons · m‐2 · s‐1, more... |
Tipo: Text |
Palavras-chave: Dinophysis; Ecophysiology; Full factorial design; Global change; Mesodinium rubrum; Teleaulax amphioxeia. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00609/72155/70910.pdf |
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Serais, Ophelie; Abadie, Eric; Hubert, Clarisse; Bellamy, Elise; Fiandrino, Annie; Lemoine, Maud; Neaud-masson, Nadine. |
Ce rapport a été réalisé à la demande de la Direction Départementale de la Protection des Populations de l’Hérault (DDPP34). Les résultats en toxines lipophiles réglementées (Acide Okadaïque, Dinophysis toxines et Pectenotoxines uniquement) dans les moules et les huîtres prélevées au point « Parc Leucate 2 » dans le cadre du REPHYTOX, ainsi que les dénombrements du phytoplancton toxique du genre Dinophysis réalisés dans le cadre du REPHY dans la lagune de Leucate, sont présentés sur des graphiques permettant une visualisation temporelle des épisodes de contamination entre janvier 2014 et décembre 2020. |
Tipo: Text |
Palavras-chave: REPHYTOX; REPHY; Leucate; Point Parc Leucate 2; Moules; Huîtres; Toxins lipophiles; Dinophysis; Graphiques; Période 2014-2020. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00662/77444/79099.pdf |
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Zendong, Suzie Zita; Kadiri, Medina; Herrenknecht, Christine; Nezan, Elisabeth; Mazzeo, Antonia; Hess, Philipp. |
Algal toxins may accumulate in fish and shellfish and thus cause poisoning in consumers of seafood. Such toxins and the algae producing them are regularly surveyed in many countries, including Europe, North America, Japan and others. However, very little is known regards the occurrence of such algae and their toxins in most African countries. This paper reports on a survey of phytoplankton and algal toxins in Nigerian coastal waters. Seawater samples were obtained from four sites for phytoplankton identification, on three occasions between the middle of October 2014 and the end of February 2015 (Bar Beach and Lekki in Lagos State, Port Harcourt in Rivers State and Uyo in Akwa Ibom State). The phytoplankton community was generally dominated by diatoms and... |
Tipo: Text |
Palavras-chave: Dinoflagellates; Dinophysis; Phycotoxins; Untargeted analysis; Phytoplankton. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00314/42521/41893.pdf |
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Soudant, Dominique. |
L'objectif de ce travail était de mettre en place un outil mathématique permettant de prévoir les concentrations en Dinophysis cf. acuminata, micro-algue toxique. Nous avons décidé d'utiliser des méthodes dynamiques de prévision bayésienne : modèles polynomiaux du premier, second et troisième ordre, modèle polynomial du premier ordre avec intervention, et modèle de régression multilinéaire. Les modèles polynomiaux du premier, second et troisième ordre se sont avérés inadaptés. Le modèle de régression multilinéaire a été testé avec les variables concentrations en phosphate (PO4) et en nitrate (NO3). Ce modèle est insatisfaisant du fait de l'inconstance des relations entre la concentration en Dinophysis cf. acuminata et les régresseurs. Le modèle polynomial... |
Tipo: Text |
Palavras-chave: Modèle dynamique bayésien; Prévision; Séries chronologiques; Dinophysis; Antifer. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00430/54178/55519.pdf |
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García-portela, Maria; Reguera, Beatriz; Gago, Jesus; Le Gac, Mickael; Rodríguez, Francisco. |
Dinoflagellate species of Dinophysis are obligate mixotrophs that require light, nutrients, and prey for sustained growth. Information about their nitrogenous nutrient preferences and their uptake kinetics are scarce. This study aimed to determine the preferred nitrogen sources in cultures of D. acuminata and D. acuta strains from the Galician Rías Baixas (NW Spain) and to compare their uptake kinetics. Well-fed versus starved cultures of D. acuminata and D. acuta were supplied with N15 labeled inorganic (nitrate, ammonium) and organic (urea) nutrients. Both species showed a preference for ammonium and urea whereas uptake of nitrate was negligible. Uptake rates by well-fed cells of D. acuminata and D. acuta were 200% and 50% higher, respectively, than by... |
Tipo: Text |
Palavras-chave: Dinophysis; Nitrate; Ammonium; Urea; Uptake rates; N-15 incubations; Antibiotic treatment. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00606/71770/70250.pdf |
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Soudant, Dominique; Beliaeff, Benoit; Thomas, G. |
Classical regression analysis can be used to model time series. However, the assumption that model parameters are constant over time is not necessarily adapted to the data. In phytoplankton ecology, the relevance of time-varying parameter values has been shown using a dynamic linear regression model (DLRM). DLRMs, belonging to the class of Bayesian dynamic models, assume the existence of a non-observable time series of model parameters, which are estimated on-line, i.e. after each observation. The aim of this paper was to show how DLRM results could be used to explain variation of a time series of phytoplankton abundance. We applied DLRM to daily concentrations of Dinophysis cf. acuminata, determined in Antifer harbour (French coast of the English... |
Tipo: Text |
Palavras-chave: Phytoplankton; Dinophysis; Time series; Regression; Dynamic; Bayesian. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00337/44784/44490.pdf |
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Le Dean, Loic; Gauthier, Franck. |
Nous avons réalisé cette étude dans le but de fournir aux agents d'IFREMER chargés de la surveillance des eaux littorales et en particulier de la flore phytoplanctonnique, un outil permettant d'identifier et de compter les cellules de Dinophysis de façon automatique. La visionique nous semblant être une discipline qui se prêtait à ce type de détection, nous avons réalisé une étude de faisabilité d'un système d'analyse d'il}1age appliqué à la reconnaissance et au comptage de Dinophysis. Le capteur utilisé est une caméra J.V.C Tri C.C.D transmettant trois images (rouge - verte - bleue) à un ordinateur compatible A.T.. Celui ci est équipé d'un ensemble de cartes MATROX de numérisation et traitement d'images et d'un coprossesseur arithmétique. Les applications... |
Tipo: Text |
Palavras-chave: Dinophysis; Phytoplancton; Visionique; Reconnaissance de forme; Segmentation; Binarisationcontours. |
Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00136/24714/22768.pdf |
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Farrell, Hazel; Gentien, Patrick; Fernand, Liam; Lunven, Michel; Reguera, Beatriz; Gonzalez-gil, Sonsoles; Raine, Robin. |
An investigation into the distribution of Dinophysis spp. in coastal waters off the south coast of Ireland was carried out in July 2007. Dinophysis acuta was present as a sub surface layer containing up to 55,000 cells L-1. The population had a high percentage of viable cells (mean: 89%; median: 94%; n = 24) with a high specific division rate (~0.55 d-1). The layer, of approximately 5 m thickness, did not coincide with the fluorescence maximum and was present as a patch of horizontal dimension less than 10 km x 7 km. Both conventional and towed undulating CTD used in conjunction with high vertical resolution sampling methods showed the patch of Dinophysis to move with a similar speed and direction as the coastal flow, which ran parallel to the coast in the... |
Tipo: Text |
Palavras-chave: Coastal jets; Dinophysis; Ireland; Transport. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00064/17538/17420.pdf |
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Registros recuperados: 30 | |
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