Sociodemographic factors and the variation in syphilis rates among US counties, 1984 through 1993: an ecological analysis

OBJECTIVES: Syphilis in the United States is focally distributed, with high incidence rates in the South and in metropolitan areas nationwide. In this study an ecological analysis, using the county as the unit of analysis, was performed to generate hypotheses about community-level determinants of syphilis rates. METHODS: Bivariate rank correlations and multivariate, backward stepwise elimination linear regressions were performed. Mean annual incidence of primary- and secondary-stage syphilis in a county was the dependent variable, and county sociodemographic characteristics (from census data) were the independent variables. RESULTS: In the multivariate regression model, sociodemographic characteristics accounted for 71% of the variation in syphilis rates among counties. With other factors accounted for, the most highly correlated characteristics were percentage non-Hispanic Black population, county location in the South, percentage of the population that was urban, percentage Hispanic population, and percentage of births to women younger than 20 years. CONCLUSIONS: Most of the variation in syphilis rates among counties is accounted for by sociodemographic characteristics. Identification and remediation of modifiable health determinants for which these factors are markers are needed to improve the health status of these populations.     

BONSAI: 3D object recognition using constrained search

BONSAI, a model-based 3D object recognition system, is described. It identifies and localizes 3D objects in range images of one or more parts that have been designed on a computer-aided-design (CAD) system. Recognition is performed via constrained search of the interpretation tree, using unary and binary constraints (derived automatically from the CAD models) to prune the search space. Attention is focused on the recognition procedure, but the model-building, image acquisition, and segmentation procedures are also outlined. Experiments with over 200 images demonstrate that the constrained search approach to 3D object recognition has an accuracy comparable to that of previous systems