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Environmental change and freshwater macroinvertebrates at Wicken Fen, CambridgeshireLee, David George January 1988 (has links)
No description available.
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The impact of agricultural practices on the aquatic invertebrate populations of ricefieldsSimpson, Ian Charles January 1992 (has links)
No description available.
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Déterminisme de la décision lysogénique au sein des communautés virales aquatiques : importance des fluctuations physiologiques et métaboliques des hôtes procaryotes / Determinism of lysogenic decision in aquatic viral communities : importance of physiological and metabolic fluctuations within prokaryotic hostsPalesse, Stephanie 05 December 2014 (has links)
Résumé indisponible / Résumé indisponible
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Flow injection chemistries for the in situ monitoring of nutrients in sea waterMcCormack, Trevor January 1996 (has links)
No description available.
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An ecophysiological study of the Elodea nuttallii-epiphyton associationJones, John Iwan January 1994 (has links)
No description available.
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Modelling phosphorus losses from agricultural catchments to surface waters using GISMcGuckin, Sara Olivia January 2000 (has links)
No description available.
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The physiological ecology of photosynthetic ciliated protozoa and their trophic roles in freshwater and brackish planktonic microbial food websPerriss, Stephen James January 1993 (has links)
No description available.
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Do diurnal dissolved oxygen cycles have diagnostic value for assessing pollution status in lakes?Ansa-Asare, Osmund Duodu January 1998 (has links)
The effects of pollutant burdens on natural cyclic patterns in aquatic ecosystems have been studied, to test the hypothesis that a parameter or parameters describing the <I>pattern of variation </I>in a single determinant, such as DO or pH, may be used to describe the status of a body of water more meaningfully than results from single spot measurements. In this study the background water quality in a Scottish and a Ghanaian lake was assessed, then <I>rafts </I>were built on the lakes (Myrtle Dam and Weija Lake respectively) creating three small lakes to test the effects of pollutant loads (<I>e.g. </I>organics and nutrients) on them. Laboratory investigations to study the behaviour of the pollutants on DO or pH cycles were carried out, and then a dynamic DO model was developed to describe the cyclic behaviour of DO. Finally, the model was used to investigate the effects of added pollutant burdens on the DO cycles. Water quality assessment of Myrtle Dam and Weija Lake by using the <I>Weighted Water Quality Index </I>proved that Weija Lake has doubtful quality with WQI 51, which needs improvement. Myrtle Dam WQI of 73 shows that the lake waters are unpolluted (or recovered from pollution). It is also well oxygenated at the surface and receives no toxic discharge. The <I>raft</I> experiments for Myrtle Dam and the Weija Lake have been used to demonstrate that, in the raft tubes, organic loadings do have effects on the oxygen cycles, and showed that there are two effects. One is that, with a small organic loading, the mean DO value dropped, then increased as the organic loading was consumed. The second is that the amplitude of the DO cycle increased as the organic loading increased from 2.5 to 5.0 mg L<sup>-1</sup> TOC for Myrtle Dam, and decreased for Weija Lake as the organic loading increased from 2.5 to 5.0 mg L<sup>-1</sup> TOC. The laboratory experiments in both Ghana and Aberdeen proved to be useful in explaining the effects of nutrients and trace elements on the DO cycles. It was evident that the higher the algal concentration, the greater was the DO cycle and 30% v/v (<I>c.a. </I>254 mg L<sup>-1</sup> chlorophyll 'a' content ≍ 17 g L<sup>-1</sup> biomass aqueous algal suspension) proved to be the most suitable concentration for investigations, because, with higher organic loadings, the 100% aqueous algal suspension proved to be too concentrated and caused total deoxygenation.
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Avaliacao ecotoxicologica do farmaco triclosan para invertebrados marinhos / Ecotoxicological assessment of the pharmaceutical tricosan for marine invertebratesCORTEZ, FERNANDO S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:33:07Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:17Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Avaliacao ecotoxicologica do farmaco triclosan para invertebrados marinhos / Ecotoxicological assessment of the pharmaceutical tricosan for marine invertebratesCORTEZ, FERNANDO S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:33:07Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:17Z (GMT). No. of bitstreams: 0 / Triclosan é um composto orgânico de baixa solubilidade que vem sendo utilizado em formulações de cremes dentais e faciais, xampu, sabonetes, embalagens de gêneros alimentícios e diversos tipos de materiais, tais como, adesivos, brinquedos, sapatos, selantes, tintas, colchão, roupas, pisos, toldos e rejuntes. O amplo uso deste composto deve-se à grande eficácia contra bactérias Gram negativas e Gram positivas. Por seu extenso uso, evidências da presença de Triclosan têm sido frequentemente relatadas em efluentes urbanos e industriais, águas superficiais e sedimentos de ambientes dulcícolas, estuarinos e marinhos, como também em organismos aquáticos como algas, peixes e mamíferos. Neste contexto, o presente estudo avaliou a toxicidade aguda e crônica de Triclosan para diferentes invertebrados marinhos de águas tropicais. Para tanto, ensaios de toxicidade aguda foram realizados com o copépodo Nitokra sp (mortalidade) e com o ouriço-do-mar Lytechinus variegatus (taxa de fertilização). Para a avaliação do efeito crônico, ensaios de toxicidade de curta duração (desenvolvimento embriolarval) foram realizados com o ouriço-do-mar L. variegatus e Perna perna. Além desses métodos, o ensaio do Tempo de Retenção do Corante Vermelho Neutro foi empregado com a finalidade de se avaliar os efeitos do Triclosan sobre a estabilidade da membrana lisossômica de hemócitos de P. perna. Na avaliação do efeito agudo, o valor médio da CL(I)50;96h encontrada para o copépodo foi de 0,20 mg.L-1 enquanto que o valor médio da CI(I)50;1h para ouriço-do-mar foi de 0,28 mg.L-1. Já na avaliação do efeito crônico, o valor médio da CI(I)50;24h para ouriço-do-mar foi de 0,14 mg.L-1 e para o molusco bivalve a média da CI(I)50;48h, foi de 0,13 mg.L-1. O efeito na estabilidade da membrana lisossômica de hemócitos de P. perna ocorreu em concentrações a partir de 12 ng.L-1. Estes resultados evidenciam o risco ecológico da introdução contínua desse composto em ambientes marinhos, e devem ser considerados para identificação de concentrações seguras e futura regulação do bactericida Triclosan na legislação ambiental nacional e internacional. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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