Associations between sociodemographic characteristics and perceptions of the built environment with the frequency, type, and duration of physical activity among trail users.

Introduction: Rail trails are elements of the built environment that support the Task Force on Community Preventive Services' recommendation to create, or enhance access to, places for physical activity (PA). The purpose of this study was to examine the associations between sociodemographic characteristics and perceptions of the built environment with the frequency, type, and duration of PA among users of an urban, paved rail trail segment.

Methods: Interviewers conducted intercept surveys with 431 rail trail users and analyzed data by using logistic regression to estimate odds ratios between sociodemographic characteristics and perceptions of the built environment on the frequency, type, and duration of PA performed on the trail.

Youth physical activity resource use and activity measured by accelerometry.

Objectives: To examine whether use of physical activity resources (eg, parks) was associated with daily physical activity measured by accelerometry.

Methods: One hundred eleven adolescents completed a travel diary with concurrent accelerometry. The main exposure was self-reported use of a physical activity resource (none /1+ resources).

Selenium, apoptosis, and colorectal adenomas.

Background: Selenium is an essential trace element found in cereals, wheat, dairy products, meat, and fish. This micronutrient may prevent carcinogenesis through several biochemical pathways; one suggested pathway is enhanced apoptosis.

Objectives: The relation between selenium and colorectal adenomas was evaluated because the colorectal adenoma is the established precursor lesion of most colorectal cancers.