ABSTRACf: This paper summarizes an investigation to characterize and treat selected storm water contaminants that are listed as toxic pollutants (termed toxicants in this paper) in the Clean Water Act, Section 307 (Arbuckle et al., 1991). The first project phase investigated typical toxicant concentrations in storm water, the origins of these toxicants, and storm and land-use factors that influenced these toxicant concentrations. Of the 87 storm water source area samples analyzed, 9% were considered extremely toxic (using the Microtox~toxicity-screening procedure). Moderate toxicity was exhibited in 32% of the samples, whereas 59% of the samples had no evidence of toxicity. Only a small fraction of the organic toxicants analyzed were frequently detected, with 1,3dichlorobenzene and fluoranthene the most commonly detected organics investigated (present in 23% of the samples). Vehicle service and parking area runoff samples had many of the highest observed concentrations of organic toxicants. All metallic toxicants analyzed were commonly found in all samples analyzed.The second project phase investigated the control of storm water toxicants using a variety of bench-scale conventional treatment processes. Toxicity changes were monitored using the Microtox~bioassay test. The most beneficial treatment tests included settling for at least 24 hours (up to 90% reductions), screening and filtering through at least 40-l'm screens (up to 70% reductions), and aeration and/or photodegradation for at least 24 hours (up to 80% reductions). Because many samples exhibited uneven toxicity reductions for the different treatment tests, a treatment train approach was selected for the current project phase. This current phase includes testing of a prototype treatment device that would be useful for controlling runoff from critical source areas (e.g.. automobile service facilities). Water Environ. Res., 67, 260 (1995).

Bedside catheterization of the right heart with a percutaneously introduced flowdirected catheter was carried out in 24 critically ill patients; 71 determinations of mixed venous oxygen saturation (MVo 2 ) were obtained. A second catheter was inserted either into a central intrathoracic vein or the right atrium for simultaneous sampling of central venous (CVo 2 ) or right atrial (RAo 2 ) oxygen saturation. For the group as a whole, mean CVo 2 (57.9% ± 15.25) was significantly greater than mean MVo 2 (53.3% ± 14.84) ( P <0.001), but there was no significant difference and correlation was good between changes in central venous compared to changes in mixed venous oxygen saturation. On the other hand, there was no significant mean difference as well as an excellent correlation between individual values of RAo 2 and MVo 2 (r=+0.95). Patients with heart failure or shock showed poor correlation between CVo 2 and simultaneously determined MVo 2 . Furthermore, subjects with shock showed a mean CVo 2 (58.0%±13.05) that was significantly greater than mean MVo 2 (47.5% ± 15.11). In contrast, there was no significant difference between mean RAo 2 and mean MVo 2 and excellent correlation of individual values in patients with either heart failure or shock. Although CVo 2 is a poor reflection of MVo 2 in subjects with severe heart failure or shock, there was a better correlation between changes in CVo 2 with corresponding changes in MVo 2 . In addition, RAo 2 correlated closely with corresponding values of MVo 2 . The reversal of the normal relationship between CVo 2 and MVo 2 under these circumstances is compatible with the thesis that low output states are attended by redistribution of blood flow away from femoral, splanchnic, and renal circulation with preferential preservation of cerebral blood flow.

Cells in the hippocampal formation show spatial firing correlates thought to be critical to the role played by this structure in spatial learning. Place cells in the hippocampus proper show location-specific activity, whereas cells in the postsubiculum fire as a function of momentary directional heading. One question which has received little attention is how these spatial signals are used by motor structures to actually guide spatial behavior. Here we present a model of how one kind of spatial behavior, instrumental learning in the Morris water maze, could be guided by the spatial information in the hippocampal formation. For this, we concentrate on the hippocampal projection to the nucleus accumbens, which is strongly implicated in instrumental learning. In the model, simulated firing patterns of place cells and head direction cells activate "motor" cells in the "accumbens." Each motor cell causes a particular locomotor movement in a simulated rat. In this way, the "rat" locomotes through the simulated environment. Each step places the animal in a slightly different location and directional orientation, which, in turn, activates a different set of place and head direction cells, thus causing the next locomotor response, and so on. Connection strengths between cells are initially set randomly. When the animal encounters the reward location, however, connections are altered, so that recently active synapses are strengthened. Thus, successful moves in a particular locational and directional context are "stamped in." Simulated rats show rapid learning, similar in many ways to that of actual rats. In particular, they generate efficient routes to the goal after minimal experience, and can do so from somewhat novel starting positions. Consideration of the model architecture shows that 1) combined use of directional and place information is an example of a linearly inseparable problem and that 2) some types of novel route generation, often thought to require a "cognitive mapping" strategy, can be generated from the S-R type model used here.

The results indicate that, among non-dependent drinkers (unlike alcohol-dependent participants), alcohol-related attentional bias is not a generalized phenomenon, but occurs only under a specific set of circumstances.