An analysis of 2001 and 2002 West Nile virus (WNV) surveillance data shows that counties that report WNV-infected dead birds early in the transmission season are more likely to report subsequent WNV disease cases in humans than are counties that do not report early WNV-infected dead birds.
The idea of a seamless, scaleless data base of digital spatial data for use in auto mated cartography or geographic information systems has intrigued researchers for a number of years. Yet reviewing the plans of mapping agencies in the United States and Europe for their digital data bases in the 1990's shows partitioning by scale, space, and time. Why is… (More)
Just as rules have been developed to measure how well a data base management system conforms to the relational model, the desirable characteristics of a spatial data base management system can be specified. Spatial data base management systems must meet the requirements of conventional data base management systems as well as provide special facilities to… (More)