Life cycle optimisation for highway best management practices.

Highway runoff can cause a number of water quantity and quality problems. Stormwater management systems for highways have been developed based on a fast drainage for large storm situations. Non-point source pollution from highway runoff is a growing water quality concern. Stormwater quality control needs to be integrated into highway drainage design and operation to reduce the stormwater impacts on the receiving water. A continuous simulation/optimisation model for analysing integrated highway best management practices (BMPs) is presented. This model can evaluate the life cycle performance of infiltration and/or storage oriented highway BMPs. It can be directly integrated with spreadsheet optimisation tools to find the least cost options for implementing BMPs throughout a specified life cycle.

Exercise influences spatial learning in the radial arm maze.

Previous studies indicate that the hippocampus is active during exercise, and that neurotrophin expression, receptor density, and survival of dentate gyrus granule cells in the hippocampus can be modified by moderate voluntary exercise. The present study was designed to test the consequences of voluntary exercise on a hippocampal-related behavior. Exercising and control rats were tested on the standard and delayed nonmatch-to-position (DNMTP) version of the eight-arm radial maze, both of which are sensitive to hippocampal damage. Voluntarily exercising rats ran in running wheels attached to their home cage for 7 weeks prior to and throughout testing, and took 30% fewer trials to acquire criterion performance than sedentary controls. Both groups spent the same average time per arm. Once the eight-arm maze had been learned to criterion, group differences were not apparent. Exercise can facilitate acquisition of a hippocampal-related spatial learning task, but does not affect performance following acquisition. Further work will be necessary to link these effects to hippocampal-related variables shown to be influenced by exercise.

The ratio of striatal D1 to muscarinic receptors changes in aging rats housed in an enriched environment.

The enriched environment (EC) causes morphological plasticity in striatal cells that express D1 and D2 receptors. We used radioligand binding assays to examine whether EC produces plasticity in striatal receptor density and receptor density ratios. After 30 days of EC, 2-year-old rats had a higher ratio of D1 to muscarinic receptors in striatum relative to singly housed rats. Assays also showed trends for a greater ratio of D1 to cannabinoid receptors and a greater density of D1 receptors in striatum after EC. D2 receptor density was unaffected by the EC condition.

Eponymous verb phrases and ambiguity resolution.

To understand eponymous verb phrases such as "do a John Travolta," readers cannot merely select a sense out of a mental lexicon (sense selection). They must create new senses (sense creation) by retrieving salient information from memory. We conducted two experiments to test the hypothesis that these processes of memory retrieval parallel those used for ordinary lexical ambiguities. To prepare for Experiment 1, we gathered readers' interpretations of eponymous verb phrases like "do a John Travolta" to establish dominant and subordinate interpretations. We then wrote story contexts that biased comprehension toward one or the other interpretation. In Experiment 1, paraphrase judgment times were used to demonstrate that dominant meanings are privileged in the sense that they are accessible even when the story creates a subordinate bias. In Experiment 2, this privilege faded somewhat when there was a delay before the paraphrase judgment. We discuss the results with respect to the distinction between sense selection and sense creation.