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31.
Norbert Schmilz 《Die Naturwissenschaften》1988,75(11):559-566
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Hohoff C Solmsdorff K Löttker P Kemme K Epplen JT Cooper TG Sachser N 《Die Naturwissenschaften》2002,89(10):462-465
A new species of wild guinea pigs from Bolivia was recently discovered: Galea sp. So far no data are available concerning its social and mating systems. We therefore investigated behavioural compatibility, sexual dimorphism, paternity in a male-competing situation, testicular and epididymal size, and sperm morphology and motility. The results showed a complete intrasexual and moderate intersexual behavioural incompatibility between unfamiliar animals, a reversed sexual dimorphism with females larger than males, and litters always fathered by single males. Furthermore, both the reproductive organ weights and the percentage of motile sperm and sperm with intact acrosomes were significantly lower compared with the promiscuous congeneric Galea musteloides. In summary, these data strongly suggest a monogamous social and mating system for the recently discovered Galea sp. 相似文献
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Norbert Caspers 《Environmental Sciences Europe》2003,15(4):246-250
The assessment of adverse effects in terrestrial ecosystems is of central importance to any Environmental Risk Assessment of Industrial Chemicals at an EU level. A conceptual proposal in this regard is clearly outlined in the ‘Technical Guidance Document’ which is currently undergoing revision; nonetheless, from an industrial point of view, there are still some unresolved questions: The design of ecotoxicological tests should not focus exclusively on reproducibility under defined laboratory conditions; of equal if not greater importance is the ecological relevance of tests, i.e. the ability of a (chronic) test system to adequately reflect substance-related effects on wild species at the population level. In readily biodegradable substances in particular, the choice of an appropriate test substrate and an optimized feeding regime as well as the analytical confirmation of nominal test concentrations is vital. Bioaccumulation of industrial chemicals in soil-dwelling organisms usually takes place via the pore water phase. Oligochaete worms such as Eisenia and Lumbricus have proven to be promising candidates for an experimental approach. However, there is still an urgent need for the development of a balanced understanding of how to evaluate the results of those studies. Variability is inherently high in terrestrial systems, making any differentiation between natural fluctuations of parameters and substance-induced effects on the structures and functions of ecosystems a difficult task. In order to strengthen their predictive value for population or ecosystem-related effects, any experimental study has to fulfill specific quality criteria (e.g. acknowledged test procedure; Good Laboratory Practice; appropriate methodological approach (including statistics); meaningful endpoints; clear linkage of results and experimental design). Only if these criteria are met can test results be used for regulatory purposes. 相似文献
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