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| Registros recuperados: 369 | |
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| Abdel-Halim, A.M.; Gharib, S.M.. |
| Species composition, abundance, and phytoplankton biomass in Lake Nasser were studied during the highest flood season in autumn 1999, and were supported by some physico-chemical environmental parameters. The nutrient salts levels were low to medium, with ranges of 0.96-9.92 g/L for nitrite, 20.14-72.14 g/L for ammonia, complete depletion -27.69 g/L for phosphate, and 5.83-9.00 g/L for silicate. A total of 71 taxa were identified, of which 46% were chlorophytes, 26% bacillariophytes and 22% cyanophytes. Phytoplankton abundance and biomass values were higher in the northern stations than in the southern, but were lower than previously reported, indicating approaching from oligomesotrophic status, with,respectively, means of 108.9 x 104 unit/L and 1.18... |
| Tipo: Journal Contribution |
Palavras-chave: Environmental Studies; Phytoplankton; Phytoplankton; Http://aims.fao.org/aos/agrovoc/c_13344. |
| Ano: 2006 |
URL: http://hdl.handle.net/1834/1454 |
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| Abikhalil, Celina; Finkelstein, Darren S.; Conejero, Genevieve; Du Bois, Justin; Destoumieux-garzon, Delphine; Rolland, Jean-luc. |
| Exposure of the toxin-producing dinoflagellate Alexandrium catenella (A. catenella) was previously demonstrated to cause apoptosis of hemocytes in the oyster species Crassostrea gigas. In this work, a coumarin-labeled saxitoxin appeared to spread throughout the cytoplasm of the hemocytes. PSTs, including saxitoxin, were also shown to be directly responsible for inducing apoptosis in hemocytes, a process dependent on caspase activation and independent of reactive oxygen species (ROS) production. A series of in vitro labeling and microscopy experiments revealed that STX and analogs there of induced nuclear condensation, phosphatidylserine exposure, membrane permeability, and DNA fragmentation of hemocytes. Unlike in vertebrates, gonyautoxin-5 (GTX5), which... |
| Tipo: Text |
Palavras-chave: Shellfish; Toxin; Harmful algae; Phytoplankton. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00391/50272/50905.pdf |
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| Ajani, Penelope A.; Lim, Hong Chang; Verma, Arjun; Lassudrie, Malwenn; Mcbean, Katie; Doblin, Martina A.; Murray, Shauna A.. |
| Certain species of the marine diatom genus Pseudo‐nitzschia are responsible for the production of the domoic acid (DA), a neurotoxin that can bioaccumulate in the food chain and cause amnesic shellfish poisoning (ASP) in animals and humans. This study extends our knowledge by reporting on the first observation of the potentially toxic species Pseudo‐nitzschia simulans from this region. One clonal strain of P. simulans was isolated from the East Australian Current and characterized using light and transmission electron microscopy, and phylogenetic analyses based on regions of the internal transcribed spacer (ITS) and the D1–D3 region of the large subunit (LSU) of the nuclear‐encoded ribosomal deoxyribonucleic acid (rDNA), as well as examined for DA... |
| Tipo: Text |
Palavras-chave: Domoic acid; East Australian current; Harmful algal blooms; Phytoplankton; Shellfish. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00618/73047/75313.pdf |
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| Akcha, Farida; Arzul, Genevieve; Rousseau, Sabrina; Bardouil, Michele. |
| The alkaline comet assay was tested on different microalgae: the clinofiagellates, Karenia mikimotoi and Alexandrium minuturn, and the diatom, Chaetoceros gracilis. The microalgae were exposed during their exponential growth to the model direct genotoxicant, hydrogen peroxide (1 h, 5 and 100 pM H2O2). Following H2O2 exposure, the comet assay was validated only for K. mikimotoi for which genotoxicity was observed from the lowest tested concentration of 5 pM with a concentration-dependent effect. C. gracilis was too small in size (4 mu m) to be correctly analysed. For A. minuturn, our lysis buffer was not strong enough to digest the cellulosic thecal plates. For K. mikimotoi, the comet assay was thus applied for the study of the genotoxic effects of... |
| Tipo: Text |
Palavras-chave: Comet assay; Genotoxicity; Pesticides; Phytoplankton. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4504.pdf |
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| Alunno-bruscia, Marianne; Bourles, Yves; Maurer, Daniele; Robert, Stephane; Mazurie, Joseph; Gangnery, Aline; Goulletquer, Philippe; Pouvreau, Stephane. |
| Many studies based on bioenergetics growth models have investigated the effects of environmental factors on oyster (Crassostrea gigas) growth and physiology. However, most of these models are site-specific and cannot be applied to other culture sites without the re-estimation of parameters or re-formulation of some processes. We aimed to develop a generic growth model suitable for application in contrasting environments, with a constant set of parameters. We tested the oyster-DEB model (Bourlès et al. 2009) for the stimulation of C. gigas growth in different cohorts (spats and adults) at major shellfish culture sites in France, in several years: Arcachon (1993–1994); Marennes-Oléron (2007); Quiberon (1999, 2000, 2001); Rade de Brest (2008); Baie du... |
| Tipo: Text |
Palavras-chave: DEB theory; Modelling; Bivalves; Crassostrea gigas; Phytoplankton; Temperature effect; Coastal environment.. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00043/15403/12762.pdf |
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| Alves-de-Souza,Catharina; Menezes,Mariângela; Huszar,Vera. |
| This paper presents the composition and functional groups of the phytoplankton from Comprida lagoon, a tropical humic coastal Lagoon located in Southeast Brazil. A total of 28 taxa was found, distributed in eight taxonomic divisions as follows: 26% Heterokontophyta, 21% Chlorophyta, 21% Cyanophyta, 14% Bacillariophyta, 14% Cryptophyta, and 4% Prymnesiophyta. Twenty-three taxa were identified at the specific and infraspecific levels, from which four are new records for Brazil and two for Rio de Janeiro State. Phytoplankton of the Comprida lagoon was comprised of several flagellates, but also eukaryote and prokaryote picoplankton, filamentous cyanobacteria and several diatoms. The biomass was lower than that found in other lacustrine systems, and showed... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phytoplankton; Tropics; Humic systems; Coastal lagoons; Functional groups; Southeast Brazil. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062006000300019 |
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| Alzieu, Claude. |
| The necessity to combat oil slicks makes it necessary to assess the relative effectiveness and toxicity of dispersal agents used. This is usually done by using individual or groups of indicator organisms. The theory behind the various approaches is outlined, and some considerations are listed for the choice of technique. 2 organisms were chosen - the Portuguese oyster (Crassostrea), and the phytoplankton alga Phaeodactylum tricornutum Bohlin, on which if feeds - and the oyster closing reaction, and level of inhibition of growth under the influence of irritant products was measured. Methods are described, and the results shown for emulsifying, agglomerating and precipitating products. The results are discussed, and the mode of interference of the products... |
| Tipo: Text |
Palavras-chave: Choice of technique; Phytoplankton; Organisms; Toxicity; Oil spills; Pollution. |
| Ano: 1972 |
URL: http://archimer.ifremer.fr/doc/1972/publication-2073.pdf |
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| Angeler, David G; Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment; david.angeler@slu.se; Drakare, Stina; Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment ; stina.drakare@slu.se; Johnson, Richard K; Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment ; richard.johnson@slu.se. |
| Revealing the adaptive responses of ecological, social, and economic systems to a transforming biosphere is crucial for understanding system resilience and preventing collapse. However, testing the theory that underpins complex adaptive system organization (e.g., panarchy theory) is challenging. We used multivariate time series modeling to identify scale-specific system organization and, by extension, apparent resilience mechanisms. We used a 20-year time series of invertebrates and phytoplankton from 26 Swedish lakes to test the proposition that a few key-structuring environmental variables at specific scales create discontinuities in community dynamics. Cross-scale structure was manifested in two independent species groups within both communities across... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Complex adaptive systems dynamics; Complex adaptive systems organization; Cross-scale structure; Discontinuities; Environmental variables; Invertebrates; Lakes; Panarchy; Phytoplankton; Resilience; Time series modeling. |
| Ano: 2011 |
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| Araujo,Gabrielle Joanne Medeiros; Barbosa,José Etham de Lucena; Barbosa,Luciana Gomes. |
| A floristic survey of the class Euglenophyceae in Panati Lake (7º11'14" S and 36º49'52" W) is presented. The samples were collected between November 2005 and April 2007 along the margins of the lake, and a total of 29 taxa were collected, described, and illustrated, comprising 11 specifics and 18 infraspecifics, with five typical and 13 non-typical varieties. The genus Trachelomonas showed the greatest richness (13 taxa), followed by the genus Lepocinclis (seven taxa). All of the 29 taxa cataloged had been previously reported for Brazil, most with wide geographical distributions, but all were new records for Paraíba State, and 25 new for northeastern Brazil - reflecting the need for more taxonomic studies of the Euglenophyceae in these locations. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Euglenophyceae; Flora; Phytoplankton. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042012000100004 |
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| Ayata, S. -d.; Levy, Marina; Aumont, Olivier; Sciandra, Antoine; Sainte-marie, J.; Tagliabue, A.; Bernard, Olivier. |
| The aim of this study is to evaluate the consequences of accounting for variable Chl:C (chlorophyll:carbon) and C:N (carbon:nitrogen) ratios in the formulation of phytoplankton growth in biogeochemical models. We compare the qualitative behavior of a suite of phytoplankton growth formulations with increasing complexity: 1) a Redfield formulation (constant C:N ratio) without photo-acclimation (constant Chl:C ratio), 2) a Redfield formulation with diagnostic chlorophyll (variable and empirical Chl:C ratio), 3) a quota formulation (variable C:N ratio) with diagnostic chlorophyll, and 4) a quota formulation with prognostic chlorophyll (dynamic variable). These phytoplankton growth formulations are embedded in a simple marine ecosystem model in a 1D framework... |
| Tipo: Text |
Palavras-chave: Biogeochemical modeling; Phytoplankton; Photo-acclimation; Redfield ratio; Internal quota; BATS; Optimization; Micro-genetic algorithm. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00159/27071/25460.pdf |
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| Registros recuperados: 369 | |
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