23 research outputs found
Influence of particle size and shape on flowability and compactibility of binary mixtures of paracetamol and microcrystalline cellulose
Juvenile growth and survival of the apple snail Pomacea canaliculata (Caenogastropoda: Ampullariidae) reared at different constant temperatures
Investigation on the impact of different proportions of components in formulations on stability of a moisture sensitive drug
Novel highly-swellable and pH-responsive slow release formulations of clotrimazole with chitosan-g-PEG/starch microparticles
The impact of the degree of intimate mixing on the compaction properties of materials produced by crystallo-co-spray drying
Applying the technique of image classification to climate science: the case of Andalusia (Spain)
Influence of Bank-Specific and Macroeconomic Variables on Credit Risk: A Case of Nepalese Commercial Banks
Juvenile food limitation in standard tests: a warning to ecotoxicologists.
Standard ecotoxicological tests are as simple as possible and food sources are mainly chosen for practical reasons. Since some organisms change their food preferences during the life-cycle, they might be food limited at some stage if we do not account for such a switch. As organisms tend to respond more sensitively to toxicant exposure under food limitation, the interpretation of test results may then be biased. Using a reformulation of the von Bertalanffy model to analyze growth data of the pond snail Lymnaea stagnalis, we detected food limitation in the early juvenile phase. The snails were held under conditions proposed for a standardized test protocol, which prescribes lettuce as food source. Additional experiments showed that juveniles grow considerably faster when fed with fish flakes. The model is based on Dynamic Energy Budget (DEB) theory, which allows for mechanistic interpretation of toxic effects in terms of changes in energy allocation. In a simulation study with the DEB model, we compared the effects of three hypothetical toxicants in different feeding situations. The initial food limitation when fed with lettuce always intensified the effect of the toxicants. When fed with fish flakes, the predicted effect of the toxicants was less pronounced. From this study, we conclude that (i) the proposed test conditions for L. stagnalis are not optimal, and require further investigation, (ii) fish flakes are a better food source for juvenile pond snails than lettuce, (iii) analyzing data with a mechanistic modeling approach such as DEB allows identifying deviations from constant conditions, (iv) being unaware of food limitation in the laboratory can lead to an overestimation of toxicity in ecotoxicological tests. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10646-012-0973-5) contains supplementary material, which is available to authorized users