This Test Guideline is designed to assess the effects of prolonged exposure to chemicals on the growth of juvenile fish. Juvenile fish in exponential growth phase are placed, after being weighed, in test chambers and are normally exposed to five sublethal concentrations of the test substance...

This Test Guideline is designed to assess the toxicity of substances to freshwater aquatic plants of the genus Lemna (duckweed). Exponentially growing plant cultures of the genus Lemna (Lemna gibba and Lemna minor usually) are allowed to grow as monocultures in, at least, five concentrations of...

Nach dem sogenannten PISA-Schock wird insbesondere in Deutschland intensiv diskutiert, wie die Qualität der schulische Ausbildung verbessert werden kann. Dabei herrscht die Überzeugung vor, dass die Qualität der schulischen Ausbildung eine wichtige Determinante des langfristigen...

Purchasing power parities (PPPs) are the rates of currency conversion that try to equalise the purchasing power of different currencies, by eliminating the differences in price levels between countries. The basket of goods and services priced is a sample of all those that are part of final...