County-level prohibition and alcohol-related fatal motor vehicle accidents

The 50 states and the District of Columbia were grouped according to whether or not they had county-level alcohol prohibition. Several motor vehicle fatality rates were calculated for each type of jurisdiction, including the single-vehicle fatality rate (an index of alcohol-related motor vehicle accidents). In all cases, motor vehicle fatality rates for drivers in states with county-level prohibition were significantly greater than in nonprohibition states. This suggests that drivers residing in counties with prohibition are compelled to drive to adjacent counties or states to drink and consequently have increased involvement in motor vehicle accidents.     

Influences of environmental salinity on the structure and function of gill mitochondrial membranes of an osmoconforming invertebrate,Crassostrea virginica

The influence of salinity acclimation on the lipids of gill mitochondrial membranes was investigated in the osmoconforming oyster Crassostrea virginica. Commercially obtained oysters were maintained at 300 or 1000 mOsm for 1 mo at 10°C and fed identical diets of cultured algae. Salinity exposure induced an increase in some of the negatively charged phospholipids. This response may be a mechanism to bind accumulated cations which would otherwise interfere with intracellular metabolism. Lower levels of n6 fatty acids were also observed at high salinities, compared to oysters in dilute seawater and are consistent with the established marine versus freshwater n6 pattern. Arrhenius plots of membrane-bound carnitine palmitoyl transferase activity failed to display a shift in breakpoints, indicating the changes observed did not influence the properties of the membrane.     

Structure of and relationships within and between the littoral,rock-substrate fish communities off four islands in the Canarian Archipelago

A total of 577 visual surveys (each of 5 min in duration and 100 m² in area) were conducted throughout 1990 and 1991 at 32 locations off four Canary islands (i.e., Alegranza, Fuerteventura, Gran Canaria and Tenerife) with the objects of describing the coastal fish community, comparing the differences in the fish fauna within and between these islands, and determining the biotic and abiotic factors related to the structure of the fish communities. A total of 76 species were recorded; the most common were Abudefduf luridus, Canthigaster rostrata, Chromis limbatus, Sparisoma cretense and Thalassoma pavo (94.28, 86.48, 52.34, 73.31, and 94.10% frequency of occurrence, respectively). The abundance and average size of the commercially important species was greater in those locations where there was less fishing pressure. The stepwise linear regression models were capable of explaining only a low amount of variation in the dependent variables (i.e., number of species, number of individuals, average size and species diversity) of the fish community. The independent variables recorded were date, time of day, depth, slope of the substrate, substrate type, percentage of sand, percentage of algae, algal height, number of sea urchins (Diadema antillarum) and the individual islands. An ANOVA, using the islands only as independent variables, indicated that each island contributed significantly to the variation in the four dependent variables and there were significant differences among the islands. Detrended correspondence analysis (DCA) and a two-way indicator species analysis (TWINSPAN) determined associations between species and environmental attributes of the survey locations. The patterns in the TWINSPAN analysis indicated that localities had faunal resemblances based on the island off which where they were located.