129 resultados para 2003-07-BS


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Crystallization of 1-butyl-3-methylimidazolium chloride from mixed ionic liquid or ionic liquid-aromatic solution, and from the melt yields different crystalline polymorphs, the first direct evidence for inhibition of crystallization in ionic liquids by polymorphism.

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The classification of a microsporidian parasite observed in the abdominal muscles of amphipod hosts has been repeatedly revised but still remains inconclusive. This parasite has variable spore numbers within a sporophorous vesicle and has been assigned to the genera Glugea, Pleistophora, Stempellia, and Thelohania. We used electron microscopy and molecular evidence to resolve the previous taxonomic confusion and confirm its identification as Pleistophora mulleri. The life cycle of P. mulleri is described from the freshwater amphipod host Gammarus duebeni celticus. Infection appeared as white tubular masses within the abdominal muscle of the host. Light and transmission electron microscope examination revealed the presence of an active microsporidian infection that was diffuse within the muscle block with no evidence of xenoma formation. Paucinucleate merogonial plasmodia were surrounded by an amorphous coat immediately external to the plasmalemma. The amorphous coat developed into a merontogenetic sporophorous vesicle that was present throughout sporulation. Sporogony was polysporous resulting in uninucleate spores, with a bipartite polaroplast, an anisofilar polar filament and a large posterior vacuole. SSU rDNA analysis supported the ultrastructural evidence clearly placing this parasite within the genus Pleistophora. This paper indicates that Pleistophora species are not restricted to vertebrate hosts.

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The aim of this study was to assess the effect of group size during the post-weaning period on the performance and behaviour of pigs. A total of 1280 pigs were allocated to one of five group sizes from weaning at 4 weeks of age until 10 weeks of age. The group sizes consisted of 10, 20, 30, 40 or 60 pigs, and groups were balanced for gender and weight. All pigs were housed at a constant space allowance and one 4-space dry feeder and drinker was provided per 10 animals. Group size did not significantly affect growth rate; however, the coefficient of variation for growth was greater in groups of 10 than in larger groups, and this reached significance (P