PURPOSE Neighborhood walkability, characterized by mixed land use, street connectivity, and residential density, has been found to be related to overall physical activity. In previous analyses, this association was significant in high income adults, but not in low income adults. The purpose of the present study was to test the hypothesis that car availability moderated the relation between neighborhood walkability and physical activity. METHODS A random sample of adults was recruited from neighborhoods in Seattle and King County, WA that varied by walkability and income. Participants reported the number of operating motor vehicles in their households. Physical activity was measured by 7 days of monitoring with Actigraph accelerometers, and mean daily minutes of moderate-to-vigorous physical activity (MVPA) were computed. A neighborhood walkability index was calculated for a 1-km radius around each participant's home based on the street network using Geographic Information Systems. Multiple regressions were conducted separately for low- and high-income participants to explain MVPA, controlling for age and sex. RESULTS Of the 624 low-income participants, 8.5% had no car. Of the 659 high-income participants, 1.8% had no car. The median of cars per household for each group was 2.0. Interactions between walkability and car availability were not significant for low- (p<.15) or high-income (p<.46) participants. In regressions without interactions for the high-income group, walkability explained 3.6% of the variance (p<.001), but car ownership explained only .003% (p<.90). Results for the low-income group showed walkability explained 1.2% of the variance (p<.01), and there was a trend for car ownership to be negatively related to MVPA (.006% of variance, p<.06). CONCLUSIONS The hypothesized moderating effect of car availability on the relation between walkability and MVPA was not supported for low- or high-income adults. However, when car availability was included in the regression model for lowincome adults, it was marginally significant, indicating further study of this variable is warranted. In contrast to previous analyses, when car availiability was in the model for low-income adults, walkability was significantly related to MVPA. Different patterns of associations between environmental variables and MVPA may be operating for different population subgroups. Supported by NIH grant HL67350.
Activation of transcription factor NF-kappaB, the major regulator of the inflammatory response, depends on the inhibitor of NF-kappaB kinase (IKK) complex, which is composed of 2 catalytic subunits, IKK1 and IKK2 (also known as IKKalpha and IKKbeta), and a regulatory subunit, IKKgamma (also known as NEMO). In this issue of the JCI, Mourkioti et al. show that muscle-specific disruption in mice of the gene encoding IKK2 prevents NF-kappaB activation in response to denervation or toxin-induced injury (see the related article beginning on page 2945). Importantly, this genetic manipulation prevents muscle wasting, thereby providing strong evidence in support of a major pathogenic role for inflammation in a variety of muscular dystrophies characterized by progressive muscle fiber degeneration.
Crime is both a societal safety and public health issue. Examining different measures and aspects of crime-related safety and their correlations may provid
Correlates of the physical activity habits of preschool children were studied in a multiethnic sample. Physical activity levels of 33 low-income children were observed systematically during free-play periods at preschool. Children spent 58% of free-play time in sedentary activities (e.g., sitting), and were vigorously active only 11% of the time. Independent variables studied were child body mass index (BMI), teacher-rated Type A behavior, and parent-reported mother BMI, father BMI, parent vigorous activity, and family cardiovascular disease (CVD) risk. The multiple regression of moderate-intensity activity was significant, with family CVD risk, parent vigorous activity, and father BMI accounting for significant amounts of variance. The results suggest that the effects of parental role modeling on child physical activity levels may extend to free-play settings far beyond the confines of the home environment.
127 Latino adults responded to a survey concerning physical activity. Respondents over-represented well educated and middle class Latinos. Subjects reporte
CASCADES of interacting regulatory genes controlling developmental pathways have been defined in organisms such as Drosophila (1–9) and the nematode Caenorhabditis elegans (10–12). The developmental regulators include transcription factors, kinases, phosphatases, growth factors,receptors, and cell-adhesion molecules. In Drosophila, products of maternally expressed genes control expression of zygotic segmentation genes, the products of which regulate homeotic gene expression; regulation is also exerted between genes of the same class. As a result, the embryo is divided into a meshwork of metameric units, each expressing a unique combination of homeotic genes. These genes contain a conserved homeobox, encoding a 60-amino acid homeodomain which functions in DNA binding. By acting as transcription factors, the homeodomain proteins orchestrate activation of a unique combination of target genes which makes the cells enter a specific morphogenetic pathway. The molecular mechanisms underlying regulation of target gene expression are poorly understood but include competition among homeo-proteins for binding to recognition elements, posttranslational modifications affecting DNA-binding and transactivation properties, and cooperation with specific cofactors. Further elucidation of regulatory mechanisms has been hampered because only a few target genes in Drosophila regulated by homeogenes have so far been identified (13, 14). Defining developmental pathways in mammalian systems has proven even more difficult. Cloning by similarity has been used to identify genes that are potentially mammalian counterparts of well characterized Drosophila transcriptional regulators (15–19). Mammalian HOX genes are homologous to the antennapedia class of homeotic genes in Drosophila and appear to be involved in determination of regional identity along the anterior-posterior axis (20, 21). The drawback of cloning by the similarity method is the difficulty in identifying physiological target genes. In a different approach, cell type-specific regulatory elements identified in well characterized genes have been the key entry point for purification and cloning (22, 23) or direct cloning (24) of transcriptional regulators.
No abstract is provided for this article.
Background. This study examined predictors of adoption and maintenance of vigorous physical activity over time in a sample of 1,719 randomly selected women and men. Methods. Based on reported frequency of vigorous exercise in a mail survey at baseline, subjects were classified as sedentary (zero sessions per week), intermediate (one to two sessions per week), or active (three or more sessions per week). Results. On the same survey subjects reported on 25 potential determinants of physical activity based on a comprehensive learning model. Twenty-four months later, 85% of subjects were resurveyed, and their physical activity levels were classified. Within each baseline category and gender subgroup, predictors of follow-up physical activity were identified. In multivariate analyses, adoption of vigorous exercise by sedentary men was predicted by self-efficacy, age (inverse), and neighborhood environment (inverse). Adoption by sedentary women was predicted by education, self-efficacy, and friend and family support for exercise. Maintenance of vigorous physical activity was predicted by self-efficacy and age (inverse) for initially active men and by education for initially active women. Conclusion. These results suggest that factors influencing adoption are different for men and women, and there may be different factors influencing adoption versus maintenance of vigorous physical activity.
Creating is recommended to promote physical activity, but potential co-benefits of such environments have not been well described. An extensive but non-systematic review of scientific and gray literature was conducted to explore a wide range of literature to understand the co-benefits of activity-friendly environments on physical health, mental health, social benefits, safety/injury prevention, environmental sustainability, and economics. Five physical activity settings were defined: parks/trails, urban design, transportation, schools, and workplaces/buildings. Key findings: • A total of 418 higher-quality findings were summarized based on direction of association and quality of source. • The overall summary indicated 22 of 30 setting by outcome combinations showed evidence of co-benefits. • Each setting had strong evidence of at least 3 of the 6 co-benefits, and parks and trails had strong evidence of all 6 co-benefits. Thus, for each setting there are multiple features that can be designed to both facilitate physical activity and produce co-benefits. • All five physical activity settings could be designed so they have positive effects on economic outcomes, including increased home value, greater retail activity, reduced health care costs, and improved productivity. • Activity-friendly design in all settings had strong evidence of environmental co-benefits based on reduced pollution and carbon emissions. • There were many gaps in evidence of co-benefits in the schools and workplace settings as well the health consequences of environments that support active travel. • Overall, there was little evidence of negative consequences of activity-friendly environments. Implications: The most important conclusion of this review is that creating communities, transportation systems, schools, and buildings that make physical activity attractive and convenient also produces a wide range of other benefits for communities. Rather than thinking that designing one feature of a transportation system or school is sufficient, we encourage decision-makers and designers to consider how features in all settings can be optimized for physical activity and multiple other benefits. We urge mayors, other city officials, and staff in multiple departments to consult these findings as an aid in decision-making.
