The purpose of the test is to measure the capacity of a chemical to activate or inhibit the transcription of a genetic construct (THb/ZIP-GFP X. laevis eleutheroembryos) either by binding to the thyroid hormone receptor or by modifying the amount of thyroid hormone available for transcription. The test is based on the use of a transgenic frog (possessing the genetic construction THb/ZIP-GFP) of the species X. laevis. GFP is a fluorescent protein that can be used to affirm the presence of the substance and to follow its action. This test is based on the quantification of fluorescence, and thus of the GFP protein, throughout the eleutheroembryo exposed to a test chemical. Indeed, if the fluorescence is > 12% by including the highest concentration of the test, the test is considered positive. Organisms are exposed in chemically inert cell culture plates (6 wells). Each well contains ten organisms in solution. In a run, 20 organisms are exposed to each test concentration. Tadpoles are exposed to the test chemical at NF stage 45 for a duration of 72 hours. A positive result of the XETA test indicates in vivo that a substance induces damage to the receptor and metabolization of the thyroid hormone. A negative result indicates that, under test conditions, the test substance does not induce detectable damage to the thyroid and its functioning.

Part of Water Quality Set - Buy all four books and save over 30% on buying separately! Bioanalytical Tools in Water Quality Assessment reviews the application of bioanalytical tools to the assessment of water quality including surveillance monitoring. The types of water included range from wastewater to drinking water, including recycled water, as well as treatment processes and advanced water treatment. Bioanalytical Tools in Water Quality Assessment not only demonstrates applications but also fills in the background knowledge in toxicology/ecotoxicology needed to appreciate these applications. Each chapter summarises fundamental material in a targeted way so that information can be applied to better understand the use of bioanalytical tools in water quality assessment. Bioanalytical tools in Water Quality Assessment can be used by lecturers teaching academic and professional courses and also by risk assessors, regulators, experts, consultants, researchers and managers working in the water sector. It can also be a reference manual for environmental engineers, analytical chemists, and toxicologists. Authors: Beate Escher, National Research Centre for Environmental Toxicology (EnTox), The University of Queensland, Australia, Frederic Leusch, Smart Water Research Facility (G51), Griffith University Gold Coast Campus, Australia. With contributions by Heather Chapman and Anita Poulsen

This Test Guideline describes an amphibian metamorphosis assay intended to screen substances which may interfere with the normal functioning of the hypothalamo-pituitary-thyroid axis. The assay was validated with the species Xenopus laevis, which is ...

A guide to the issues relevant to the design, analysis, and interpretation of toxicity studies that examine chemicals for use in the environment Statistical Analysis of Ecotoxicity Studies offers a guide to the design, analysis, and interpretation of a range of experiments that are used to assess the toxicity of chemicals. While the book highlights ecotoxicity studies, the methods presented are applicable to the broad range of toxicity studies. The text contains myriad datasets (from laboratory and field research) that clearly illustrate the book's topics. The datasets reveal the techniques, pitfalls, and precautions derived from these studies. The text includes information on recently developed methods for the analysis of severity scores and other ordered responses, as well as extensive power studies of competing tests and computer simulation studies of regression models that offer an understanding of the sensitivity (or lack thereof) of various methods and the quality of parameter estimates from regression models. The authors also discuss the regulatory process indicating how test guidelines are developed and review the statistical methodology in current or pending OECD and USEPA ecotoxicity guidelines. This important guide: Offers the information needed for the design and analysis to a wide array of ecotoxicity experiments and to the development of international test guidelines used to assess the toxicity of chemicals Contains a thorough examination of the statistical issues that arise in toxicity studies, especially ecotoxicity Includes an introduction to toxicity experiments and statistical analysis basics Includes programs in R and excel Covers the analysis of continuous and Quantal data, analysis of data as well as Regulatory Issues Presents additional topics (Mesocosm and Microplate experiments, mixtures of chemicals, benchmark dose models, and limit tests) as well as software Written for directors, scientists, regulators, and technicians, Statistical Analysis of Ecotoxicity Studies provides a sound understanding of the technical and practical issues in designing, analyzing, and interpreting toxicity studies to support or challenge chemicals for use in the environment.

"Amphibians are facing an extinction crisis, but getting to the facts has been difficult. "Threatened Amphibians of the World" is a visual journey through the first-ever comprehensive assessment of the conservation status of the world's 6,000 known species of frogs, toads, salamanders, and caecilians. All 1,900 species known to be threatened with extinction are covered, including a description of threats to each species and an evaluation of conservation measures in place or needed. Each entry includes a photograph or illustration of the species where available, a distribution map, and detailed information on range, population and habitat and ecology. Introductory chapters present a detailed analysis of the results, complemented by a series of short essays written by many of the world's leading herpetologists. Appendices include annoted lists of lower risk species and a country-by-country listing of threatened amphibians."--pub. desc.

This Test Guideline is designed to assess effects of prolonged exposure to chemicals on the reproduction and survival of the hermaphrodite freshwater snail Lymnaea stagnalis (the Great Pond Snail).