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| Registros recuperados: 58 | |
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| Long, Marc; Tallec, Kevin; Soudant, Philippe; Lambert, Christophe; Le Grand, Fabienne; Sarthou, Geraldine; Jolley, Dianne; Hegaret, Helene. |
| Harmful microalgal blooms are a threat to aquatic organisms, ecosystems and human health. Toxic dinoflagellates of the genus Alexandrium are known to produce paralytic shellfish toxins and to release bioactive extracellular compounds (BECs) with potent cytotoxic, hemolytic, ichtyotoxic and allelopathic activity. Negative allelochemical interactions refer to the chemicals that are released by the genus Alexandrium and that induce adverse effects on the physiology of co-occurring protists and predators. Releasing BECs gives the donor a competitive advantage that may help to form dense toxic blooms of phytoplankton. However BECs released by Alexandrium minutum are uncharacterized and it is impossible to quantify them using classical chemical methods.... |
| Tipo: Text |
Palavras-chave: Harmful algal bloom; Alexandrium; Allelopathy; Cytotoxicity; PAM fluorometry; Bioassay. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00453/56424/58116.pdf |
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| BRAGA,Andrina Guimarães Silva; SOUZA,Krishna Ferri Alencar de; BARBIERI,Fabio da Silva; FERNANDES,Cleberson de Freitas; ROCHA,Rodrigo Barros; VIEIRA JUNIOR,José Roberto; LACERDA,Clariana Lins; CELESTINO,Caroline Oliveira; FACUNDO,Valdir Alves; BRITO,Luciana Gatto. |
| ABSTRACT The strategies to control the cattle tick, Rhipicephalus microplus are based mainly on the use of synthetic pesticides. However, the emergence, establishment, and development of resistance of ticks is rendering the main chemical groups ineffective. Finding new molecules to effectively control infestations by R. microplus is necessary to maintain the productivity of cattle herds, particularly of taurine breeds established in equatorial and tropical regions of the world. Ethanol extracts from the leaves, stems, and fruits of Piper tuberculatum were evaluated in bioassays at concentrations of 50, 25, 12.50, 6.25, 3.12 and 1.56 mg mL-1. The concentrations lethal to 50% of the individuals (LC50) of tick larvae after 24 hours of exposure were 3.62, 3.99... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cattle tick; Bioassay; Active molecules; Piperaceae. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672018000100057 |
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| Kreutz,Luiz Carlos; Barcellos,Leonardo José Gil; Silva,Tális Oliveira; Anziliero,Deniz; Martins,Daiana; Lorenson,Monique; Marteninghe,Ariane; Silva,Leonardo Bolognese da. |
| Toxicity risks of agricultural pesticides to fishes are pivotal. Currently, many questions remain unsolved regarding to the toxicity of commonly used pesticides to silver catfish (Rhamdia quelen), a South American catfish. The present studies have been designed to investigate the acute toxicity and the lethal concentration (LC50) of four herbicides, two fungicides and two insecticides to silver catfish fingerlings. All experiments were carried out in triplicates, in a static bioassay system, using commercially available pesticides. The data was analyzed through the Trimmed Spearman-Karber method available from the Environmental Protection Agency. The 96hLC50 and 95% lower and upper confidence limits, respectively, for the following pesticides were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bioassay; Toxicity; Pesticides; LC50; Rhamdia quelen. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782008000400022 |
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| SILVA,K.S.; FREITAS,F.C.L.; BRAGA,D.F.; DOMBROSKI,J.L.D.; SANTOS,A.F.B.. |
| ABSTRACT Ametryn is one of the most widely used herbicides in the sugarcane culture. Little is known about the interactions between this herbicide and the attributes of soils in the sugarcane region of northeastern Brazil. This knowledge, before recommending herbicide, will minimize the negative effects on the environment, particularly on water resources, and will ensure weed control efficacy. In this work, ametryn leaching potential was estimated through bioassays and chromatography, in five soils from the sugarcane region in northeastern Brazil: Quartzarenic Neosol (Entisol); Red Argisol (Ultisol); Ferrihumiluvic Spodosol (Spodosols); Red-Yellow Acrisol (Oxisol) and Haplic Cambisol (Inceptisols). To achieve this, columns were prepared with samples of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide; Liquid chromatography; Bioassay; Mobility. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000400839 |
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| Zequi,João A. C.; Lopes,José. |
| Culex (Culex) saltanensis Dyar, 1928 can become a problem in urban centers because they reproduce abundantly in ponds organically enriched. It is vector of the Plasmodium spp. and Crithidia ricadoi Sibajev et al. 1993. This research verifies the efficacy of Bacillus thuringiensis israelensis on C. saltanensis in two temperature situations, both in laboratory and field conditions. LC50 for C. saltanensis immatures fourth instar, was 0.154 ppm and the LC95 was 0.248 ppm an average temperature of 25.7ºC. When exposed at a constant temperature of 12±1ºC and a photoperiod of 14L:10D, had its susceptibity decreased in 1.50 times in reation to LC50, when compared to room temperature. B. thuringiensis israelensis is highly efficient in the control of this mosquito... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bioassay; Mosquito control; Immature Culicidae. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752007000100020 |
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| Bragadeeswaran,S; Therasa,D; Prabhu,K; Kathiresan,K. |
| Specimens of the pufferfish Arothron hispidus collected at Parangipettai, on the southeast coast of India, were subjected to bacterial isolation and identification. Three species were identified, namely Bacillus sp., Kytococcus sedentarius and Cellulomonas fimi. Partially-purified microbial filtrates exhibited hemolytic activity on chicken and human erythrocytes of O, B and AB blood groups, with maximum activity of 32 HU. The microbial filtrates also presented ATPase, Mg2+-ATPase, Na+K+-ATPase and AchE enzymatic activities of positive neuromodulation in Kytococcus sedentarius with 1300, 300.1, 1549.98 and 140.55%, in Cellulomonas fimi with 620, 300, 10 and 128.42%, and in Bacillus species with 40, 200, 849.98 and 158.69%, respectively. Toxicity symptoms... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Arothron hispidus; Tetrodotoxin; Bioassay; ATPase and AchE enzymatic activities; Anticancer activity. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992010000300008 |
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| Bustos-Obregon,Eduardo; Vargas,Álvaro. |
| A chronic toxicity bioassay was conducted with the microcrustacean Artemia salina as the testing organism for the toxic organophosphate diazinon in order to determine if the species is an appropriate indicator of pollution in aquatic environments. Tests of animal exposure to different concentrations of the toxicant were performed for 24, 48 and 72 hours after larvae hatching. Registered mortality data was used to obtain the lethal dose 50 (LD50) of the organophosphate for each exposure time, considering the immobilization of A. salina larvae as the mortality parameter. The lethal concentration (LD50) in the same exposure times was calculated by evaluating morphological changes on the three initial stages of larval development. Both doses were determined by... |
| Tipo: Journal article |
Palavras-chave: Diazinon; Artemia salina; Ecotoxicology; Bioassay. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602010000300013 |
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| NÚÑEZ FRÉ,F.R.; JUAN,V.F.; YANNICCARI,M.; SAINT ANDRÉ,H.M.; FERNANDEZ,R.R.. |
| ABSTRACT: Euphorbia davidii (Euphorbiaceae) is a summer annual weed present in the Province of Buenos Aires, Argentina. The aim of this study was to compare the sensitivity to glyphosate of different populations of Euphorbia davidii. Two techniques were used: a seed bioassay and shikimate determination in glyphosate-treated plants. Germination rates of seeds belonging to the populations from Espartillar, Barrow, Olavarria and Azul exposed to different concentrations of glyphosate were compared. Plants from the same locations treated with glyphosate were evaluated to determine shikimate levels. The most sensitive population was from Espartillar, with a CE50 (average effective concentration) of 4.00 g e.a. L-1. Based on this finding, the resistance index for... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide resistance; Germination; Bioassay; Shikimate; EUDA5. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100209 |
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| Palacio,Soraya Moreno; Espinoza-Quiñones,Fernando Rodolfo; Galante,Raquel Manozzo; Zenatti,Dilcemara Cristina; Seolatto,Araceli Aparecida; Lorenz,Evandro Kleber; Zacarkim,Carlos Eduardo; Rossi,Nickeli; Rizzutto,Márcia de Almeida; Tabacniks,Manfredo Harri. |
| The present work was performed using the common onion (Allium cepa L.) as a bioindicator of toxicity of heavy metals in river water. The test waters were collected at two sampling sites: at the beginning and the end of the Toledo River. The bulbs of A. cepa L. were grown in test water with nine concentration levels of copper, zinc and lead from 0.1 to 50 ppm. In the laboratory, the influence of these test liquids on the root growth was examined during five days. For test liquids containing below 0.03-ppm dissolved Cu the root growth was reduced by 40% However, the same reduction occurred for 1-ppm dissolved Zn. For dissolved Pb, results reveal toxicity above 0.1 and 0.6 ppm at the beginning and the end of the Toledo river water, respectively. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Acute toxicity; Bioassay; Copper; Zinc; Lead; Allium cepa L. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000400024 |
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| YAMAGUCHI, Toshiro; SAWANO, Kaita; KISHIMOTO, Miori; FURUHAMA, Kazuhisa; YAMADA, Kazutaka; 山田, 一孝. |
| Soil samples from the ground surface and feces and blood from a mixed-breed male pig were collected on April 10, 2011 at a farm within 20 km of the Fukushima Daiichi nuclear power plant. The radioactivity of each sample was measured using a Ge semiconductor detector. Despite the fact that the pig had been fed non-contaminated imported feed, 131I, 134Cs and 137Cs were detected in the feces, and 134Cs and 137Cs were detected in the blood clots. Because it is considerably difficult to measure radioactive contamination in the edible muscle of living livestock, bioassays are an option for the screening of radioactive contamination in living livestock to ensure food safety. |
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Palavras-chave: Bioassay; Cesium; Fukushima; Iodine; Radioactive contamination. |
| Ano: 2012 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3893 |
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| Destéfano,Ricardo Henry Rodrigues; Bechara,Ivanira José; Messias,Claudio Luiz; Piedrabuena,Aquiles Eugênico. |
| The study evaluated the effectiveness of Metarhizium anisopliae var. anisopliae (Hyphomycetes : Moniliales) strain E9, isolated from the pasture spittlebug Deois flavopicta (Hemiptera : Cercopidae), against larvae, prepupae and pupae stage and emergent adults of Anastrepha fraterculus, the South American fruitfly. The bioassay was carried out simulating field conditions, on autoclaved (AS) and non-autoclaved (NAS) soil from typical citrus orchards in the State of São Paulo, Southeastern region of Brazil. Various concentrations of conidia were incorporated into the soil the mortality, calculated based on the percentage of adult emergence, was 86% for the highest conidia concentrations: 2.52 x 10(10) for AS and 2.52 x 10(10) for NAS. The lethal concentration... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Microbial control; Metarhizium anisopliae; Anastrepha fraterculus; Fruitfly; Bioassay. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822005000100018 |
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| Beiras, R; His, Edouard. |
| The effects of Hg concentrations ranging from 0 (control) to 1024 mu g l(-1) upon embryogenesis, survival and growth of Mytilus galloprovincialis mussel larvae were investigated. Embryogenesis was abnormal in 50% of the individuals at 10 mu g l(-1). The 48 h LC(50) for D-shaped, early umbonate, late umbonate and eyed larvae were 51, 164, 322 and 383 pg l(-1) respectively. The LC(50) was an allometric function of ash-free dry weight with exponent b = 0.60. Larval growth was significantly reduced after 6 d exposure to 4 mu g Hg l(-1) and after 10 d exposure to 2 mu g l(-1). No significant differences in lethal or sublethal sensitivity to Hg were found between M. galloprovincialis and previously studied Crassostrea gigas embryos and larvae. The implications... |
| Tipo: Text |
Palavras-chave: Mercury; Mytilus; Mussel; Larva; Growth; Embryo; Bioassay; Ecotoxicology. |
| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00258/36946/35665.pdf |
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| Registros recuperados: 58 | |
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