A Four Country Comparision of Spite, Cooperation and Errors in Voluntary Contribution Mechanisms.

This paper presents data from experiments with a linear voluntary contributions mechanism for public goods conducted in Japan, the Netherlands, Spain and the USA. The same experimental design was used in the four countries.EXPERIMENTS ; VOLUNTARY SERVICES ; PUBLIC GOODS

Impact of Polymers on the Solution Crystal Growth Rate of a Poorly Water-Soluble Active Pharmaceutical Ingredient

Poor aqueous solubility is a major impediment to the oral delivery of over 75% of pharmaceutical compounds currently under development. The bioavailability of these compounds can be enhanced with the use of supersaturating dosage forms, due to their high flux rates across the gastrointestinal tract membrane. However, the success of this strategy hinges on the ability to inhibit crystallization of the supersaturated drug solutions. Polymers can be used to inhibit crystallization and prolong supersaturation, however the mechanisms of polymer inhibition are not yet fully understood. Therefore it is desirable to understand the attributes that render a polymer effective. In this work, the crystal growth rate of a poorly soluble pharmaceutical compound, felodipine, was measured in the presence of various polymers. The growth rate studies were performed using a rotating disk apparatus so that the growth kinetics could be controlled and mathematically modeled. It was found that both polymer ionization state and polymer hydrophobicity greatly impacted polymer effectiveness. Investigation of these systems with atomic force microscopy (AFM) revealed that these properties significantly impacted adsorbed polymer conformation. The polymers that adsorbed in an extended chain conformation were able to achieve a higher degree of surface coverage than those that adsorbed in a coiled globule formation. The surface coverage was found to directly correlate to polymer effectiveness. By modeling this correlation using the Kubota-Mullin model, polymer effectiveness could be predicted when surface coverage was known. This research also assessed the ability of a polymer to impact crystal morphology. It was found that when polymers were present during crystal evolution from an amorphous melt, they were able to impact the size and shape of the resulting crystals. This in turn influenced the rate of crystal growth from supersaturated solutions

Deliverable 2: Report on the production of GIF by turbot, the effects on growth performance of turbot of local GIF production within RAS and the presence of GIF at commercial farm level

One of the working hypotheses of this project is that growth retardation of turbot cultured in recirculating aquaculture systems (RAS) is caused by the accumulation of growth inhibiting factors (GIF) produced by the turbot themselves in the culture water. Our first goal was to demonstrate the production of growth inhibiting factors by turbot following the methodology of Yurl and Perlmutter. A series of successive experiments was performed. Extracts from turbot culture water were tested for GIF presence in early life stage tests using eggs and larvae and small scale growth trials with juveniles. Our second goal was to demonstrate the transfer of GIF between tanks. Four experiments involving the integration of experimental tanks in a farm scale setting were performed. Our third goal was to demonstrate the presence of GIF at commercial farms. Two juvenile growth trials were performed