Through isotopic analysis of Viviparus lentus (V. lentus) a high resolution record of stepwise changes in δ18O and δ13C across the Eocene / Oligocene transition and Oi-1 glacial maximum has been produced for the continental Solent Group strata, Isle of Wight (UK). Comparison of this V. lentus δ18Ocarb. record with high resolution marine δ18Ocarb. records shows that similar isotopic shifts exist in the near coastal continental and marine realms. In order to calculate palaeotemperatures from this new continental record an investigation into the biology of modern Viviparus and its effect on the isotopic composition of its shell carbonate was undertaken. Experimental measurements of the 18O/16O isotope fractionation between the biogenic aragonite of Viviparus and its host freshwater were undertaken on samples derived from the Somerset Levels in order to generate a genus specific thermometry equation. The results from using this new Viviparus equation on fossil V. lentus shell fragments suggests that aquatic and terrestrial biota were being affected by climate change associated with the Late Eocene Event. This conicides with a decrease in mammal species richness in the Osborne Member, reaching its climax at the end of the Osborne / Seagrove Bay Members. This event is followed by a brief warming in the Bembridge Limestone which was marked by a within-Europe mammal turnover involving dispersal from the south and an increase in species richness, concurrent with this is an increase in size of Harrisichara gyrogonites. An additional investigation into seasonal isotopic variability using whole well preserved V. lentus specimens has also revealed a shift from tropical /subtropical to temperate climatic zones occurring before the Eocene /Oligocene boundary and Oi-1 glacial maximum. Overall the evidence provided by these investigations would suggest that climatic change was already in progress prior to the build up of glacial ice on Antarctica.

Tierärztl. Hochsch., Diss., 2004--Hannover.

Evidence of feminising effects, including additional or enlarged female organs, have been reported in the (sub)-tropical freshwater prosobranch Marisa cornuarietis exposed to vertebrate estrogen receptor agonists. The primary symptom is an increase in the number of eggs laid, but this is only observed when exposure occurs at relatively low temperatures. This research project exposed temperate freshwater prosobranchs and a pulmonate to 17β-oestradiol (10-200 ngL-l, nominal) in an outdoor mesocosm subject to natural seasons to determine whether similar effects occur in European native temperate freshwater gastropods. Laboratory exposures to 17β-oestradiol (1-100 ngL-l, nominal) and Bisphenol-A (0.2-20 ngL-l, nominal) were also carried out over a range of different temperatures and photoperiods to simulate natural seasons. In the mesocosm exposures, significant increases in reproduction were measured in Viviparus viviparus, Bithynia tentaculata and, if the mortality rate was not significantly increased, Planorbarius corneus. It was observed that increases only occurred after the onset of autumn. In the laboratory, the oviposition rate in P. corneus was constant at 20oC with a 16h photoperiod, but declined significantly at 15oC with a 12h photoperiod, except at 100 ngL-l 17β-oestradiol, when the rate remained constant. There were no similar effects from Bisphenol-A exposure. Small increases in reproduction were observed in all the prosobranch exposures to both compounds, but the interpretation of the data was confounded by several factors (test chemical degradation, high mortality rates and parasitized organisms) and there were no significant differences. In conclusion, there were indications that all of the assessed species were capable of increased reproduction, and in P. corneus this appears to be a perpetuation of summer oviposition rates in autumnal conditions. The consequences of this effect in annual semelparous pulmonates may not be detrimental at the population level, but the long-term fitness of iteroparous prosobranchs that practice ‘restrained reproduction’ in early breeding seasons may be adversely affected.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2008. / Härtill 3 uppsatser.

Orientador: Elizabeth Moreira dos Santos Schmidt / Resumo: Este trabalho encontra-se dividido em três capítulos. O capítulo 1 versa sobre uma revisão de literatura que teve como objetivo a realização de um levantamento retrospectivo sobre os endoparasitas em bovinos no Brasil, que também incluiu dados mundiais. No capítulo 2, objetivou-se investigar os nematódeos gastrintestinais (GI) e pulmonares que parasitam bovinos jovens. Para isso, foram utilizados 140 bezerros mestiços, de dois a 12 meses de idade, clinicamente saudáveis, de duas propriedades leiteiras nos municípios de Botucatu e Manduri, estado de São Paulo. Durante um ano, trimestralmente, amostras de fezes foram coletadas diretamente da ampola retal para a realização da contagem de OPG pela técnica de McMaster modificada e pesquisa de L1 de Dictyocaulus viviparus pela modificação da técnica de Baermann. Além disso, coproculturas foram realizadas em pool de amostras para a observação das larvas infectantes. Na propriedade de Manduri, houve um aumento significativo da contagem de OPG no inverno. Na propriedade de Botucatu, os animais com até três meses de idade apresentaram maiores contagens de OPG quando comparados aos animais mais velhos. Em geral, foram observados ovos de estrongilídeos, Strongyloides spp., Moniezia spp., Trichuris spp. e oocistos de Eimeria spp. Nas coproculturas, em ordem de prevalência, foram recuperadas larvas infectantes de Cooperia spp., Haemonchus spp., Oesophagostomum spp. e Trichostrongylus spp. As L1 de D. viviparus foram recuperadas somente na ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work was divided into three chapters. The chapter 1 aimed to perform a review article based on a retrospective survey of epidemiological studies examining endoparasites that affect bovine in different regions of Brazil, which also included international data. The chapter 2 aimed to determine the gastrointestinal (GI) and pulmonary parasites that affect calves. For this, we used 140 clinically healthy crossbred calves, two to 12 months old, which belonged to two private farms in the municipalities of Botucatu and Manduri, São Paulo state. The animals were monitored for 12 months. Feces were collected directly from the rectum every three months. Fecal egg counts were determined using the modified McMaster technique with a sensitivity of 50 eggs per gram of feces (EPG). Coproculture was performed on pooled samples to identify Strongylida infective larvae. First-stage larvae of Dictyocaulus viviparus were identified by a modified Baermann method. The calves from Manduri farm showed a significant increase in the fecal egg counts in the winter when to compare to other seasons. The Botucatu farm calves differed significantly in the age groups in that younger calves (2 – 3 months old) showed a higher EPG than older calves (8 – 12 months old). Generally, we found Strongyle type-eggs, Strongyloides spp., Moniezia spp., and Trichuris spp. eggs and Eimeria spp. oocysts. The most prevalent genera in all coprocultures were: Cooperia spp., Haemonchus spp., Oesophagostomum spp., and Tri... (Complete abstract click electronic access below) / Mestre

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 4 uppsatser.