Abstract-The extensive database of acute and chronic aquatic toxicity data for alkylphenol ethoxylates (APEs) and selected biodegradation intermediates was reviewed and summarized for freshwater and saltwater aquatic microorganisms, algae, invertebrates, and fish inhabiting cold and warm water bodies. Most acute toxicity studies that tested APE-9 and APE-10, the most common commercially relevant APEs, reported results that ranged from about 1,000 to 10,000 g/L. Results from studies testing alkylphenols, intermediate by-products of APE biodegradation, ranged from about 20 to 3,000 g/L. Chronic values are a factor of about 2 to 10 lower. Although most studies used one of several common species and standard protocols to assay conventional endpoints, many nontraditional species and toxicological endpoints were also used. This toxicological database encompasses virtually all important types of aquatic habitats and classes of aquatic species. Bioaccumulation data from both laboratory and field studies indicate that alkylphenols have a low to moderate bioaccumulation potential. Fresh weight, nonlipid-based bioconcentration factors (BCFs) measured in the laboratory ranged from Ͻ1 to 1,250 for fish and 1 to 3,400 for invertebrates, whereas field bioaccumulation factors (BAFs) ranged from 6 to 487, with most values Ͻ100. Overall, these data provide an extensive and useful database to support environmental risk assessment activities.

The last twenty years of health care research has seen a steady stream of common health care data models implemented for multi-organization research. Each model offers a uniform interface on data from the diverse organizations that implement them, enabling the sharing of research tools and data. While the groups designing the models have had various needs and aims, and the data available has changed significantly in this time, there are nevertheless striking similarities between them. This paper traces the evolution of common data models, describing their similarities and points of departure. We believe the history of this work should be understood and preserved. The work has empowered collaborative research across competing organizations and brought together researchers from clinical practice, universities and research institutes around the planet. Understanding the eco-system of data models designed for collaborative research allows readers to evaluate where we have been, where we are going as a field, and to evaluate the utility of different models to their own work.

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This section is designed for the discussion and debate of current economic problems. Contributions which raise new issues or comments on issues already raised are welcome. Stuck in low GEAR? Macroeconomic policy in South Africa, 1996-98 John Weeks* Despite its ideology while in opposition, once in power the ANC government implemented an orthodox macroeconomic policy which stressed deficit reduction and a tight monetary policy, combined with trade liberalisation. The stated purpose of this package (the Growth, Employment, and Redistribution programme, or GEAR) was to increase economic growth, with a 4-2% rate programmed for 1996-2000. At mid-term of the programme, growth remained far below this target. The GEAR'S lack of success cannot be explained by unfavourable external factors; rather, the disappointing performance seemed the result of fiscal contraction and excessively high interest rates.