Background The built environment can constrain or facilitate physical activity. Most studies of the health consequences of the built environment suffer from problems of selection bias associated with confounding effects of residential choice and transportation decisions. Purpose To examine the cross-sectional associations between objective and perceived measures of the built environment, BMI, obesity (BMI>30 kg/m2), and meeting weekly recommended physical activity (RPA) levels through walking and vigorous exercise. To assess effect of using light rail transit system (LRT) on changes in BMI, obesity, and meeting weekly RPA levels. Methods Data were collected on individuals before (July 2006–February of 2007) and after (March 2008–July 2008) completion of a light rail system in Charlotte, NC. BMI, obesity, and physical activity levels were calculated for a comparison of these factors pre- and post-LRT construction. A propensity score weighting approach adjusted for differences in baseline characteristics among LRT and non-LRT users. Data were analyzed in 2009. Results More positive perceptions of one’s neighborhood at baseline were associated with a −0.36 (p<.05) lower BMI, 15% lower odds (95% CI=0.77, 0.94) of obesity, 9% higher odds (95% CI = 0.99, 1.20) of meeting weekly RPA through walking, and 11% higher odds (95% CI= 1.01, 1.22) of meeting RPA levels of vigorous exercise. The use of light rail transit to commute to work was associated with an average −1.18 reduction in BMI (p<0.05) and an 81% reduced odds (95% CI= 0.04, 0.92) of becoming obese over time. Conclusions The results of this study suggest that improving neighborhood environments and increasing the public’s use of LRT systems could provide improvements in health outcomes for millions of individuals.

Surface-enhanced resonance Raman scattering (SERRS) from silver nanoparticles using 514.5-nm excitation has been shown to offer huge potential for applications in highly sensitive multiplexed DNA assays. If the technique is to be applied to real biological samples and integrated with other methods, then the use of gold nanoparticles and longer wavelengths of excitation are desirable. The data presented here demonstrate that dye-labeled oligonucleotide sequences can be directly detected by SERRS using gold nanoparticles in a quantitative manner for the first time. The performance of gold and silver nanoparticles as SERRS substrates was assessed using 514.5-, 632.8-, and 785-nm excitation and a range of 13 commercially available dye-labeled oligonucleotides. The quantitative response allowed the limit of detection to be determined for each case and demonstrates that the technique is highly effective, sensitive, and versatile. The possibility of excitation at multiple wavelengths further enhances the multiplexing potential of the technique. The importance of effectively combining the optical properties of the nanoparticle and the dye label is demonstrated. For example, at 632.8-nm excitation, the dye BODIPY TR-X and gold nanoparticles make a strong SERRS combination with very little background fluorescence. This study allows the choice of nanoparticle and dye label for particular experimental setups, and significantly expands the applicability of enhanced Raman scattering for use in many disciplines.

Drawing on school climate theory and social disorganization theory, this article examines the influence of major institutional and community factors on disorder in Philadelphia public schools. Using U.S. census data, school district data, and police data, the authors examined the following predictors of disorder in 43 middle schools: community poverty and residential stability, community crime, school size, and school stability. Community was conceptualized in two ways: local (the census tract around the school) and imported (aggregated measures from the census tracts in which students actually reside). Previous studies have failed to make this distinction when assessing community-level influences on school disorder. The authors used path analysis to examine direct and indirect relationships between community characteristics (poverty, residential stability, crime rates), school size, school stability (a factor score based on student attendance and turnover), and school disorder (a factor score based on school incident data and dismissal rates). The local community model fit the data better than the imported model: The communities immediately surrounding schools have a stronger influence on school disorder than the communities from which students are drawn. Community poverty exerted strong indirect effects on school disorder in both models. The effects of community variables on school disorder were strongly mediated by school stability, illustrating that analyses of institutional processes have much to add to the explanation of school disorder.

Using a national survey of U.S. residents this study examines racial, socioeconomic, and community explanations for the trust of local police. We hypothesize that the construct of social capital offers a nexus for explaining racial differences in attitudes toward the police. We measure social capital as a construct by aggregating together measures that assess the degree of trust and civic engagement in communities. The results indicate that depleted levels of perceived community social capital contribute to higher levels of distrust of local police. Social capital, however, partially mediates the relative distrust of Blacks toward the police. These findings suggest only partial support for a social capital explanation of Blacks’ distrust in the police. The implications of these findings for police reform efforts to mend minority relations in urban cities are discussed.