Development of an Accelerometer-Linked Online Intervention System to Promote Physical Activity in Adolescents

Most adolescents do not achieve the recommended levels of moderate-to-vigorous physical activity (MVPA), placing them at increased risk for a diverse array of chronic diseases in adulthood. There is a great need for scalable and effective interventions that can increase MVPA in adolescents. Here we report the results of a measurement validation study and a preliminary proof-of-concept experiment testing the impact of Zamzee, an accelerometer-linked online intervention system that combines proximal performance feedback and incentive motivation features to promote MVPA. In a calibration study that parametrically varied levels of physical activity in 31 12-14 year-old children, the Zamzee activity meter was shown to provide a valid measure of MVPA (sensitivity in detecting MVPA = 85.9%, specificity = 97.5%, and r = .94 correspondence with the benchmark RT3 accelerometer system; all p < .0001). In a subsequent randomized controlled multi-site experiment involving 182 middle school-aged children assessed for MVPA over 6 wks, intent-to-treat analyses found that those who received access to the Zamzee intervention had average MVPA levels 54% greater than those of a passive control group (p < 0.0001) and 68% greater than those of an active control group that received access to a commercially available active videogame (p < .0001). Zamzee’s effects on MVPA did not diminish significantly over the course of the 6-wk study period, and were statistically significant in both females and males, and in normal- vs. high-BMI subgroups. These results provide promising initial indications that combining the Zamzee activity meter with online proximal performance feedback and incentive motivation features can positively impact MVPA levels in adolescents.     

A comparison of blood gases and acid-base measurements in arterial, arterialized venous, and venous blood during short-term maximal exercise

The purpose of this study was to determine the relationship between blood gases and acid-base measurements in arterial, arterialized venous, and venous blood measured simultaneously during short-term maximal exercise. Ten well-trained male cyclists performed a graded maximal exercise test on a cycle ergometer to determine the power output corresponding to their peak oxygen consumption (test I), and a short-term maximal test on a cycle ergometer at peak power output (test II). During test II arterial, arterialized venous and venous blood were sampled simultaneously for determination of partial pressures of oxygen and carbon dioxide, pH, bicarbonate (HCO3-), base excess (BE), and lactate (La). Samples were taken at rest, the end of 1 min of exercise (1 ME), at the end of exercise (EE), and at 2 min of recovery (REC). During test II, subjects maintained a peak power output of 370.6 (62.1) W [mean (SD)] for 4.5, SD 1.6 min. Except at rest venous and arterialized venous measurements tended to be the same at all sampling intervals, but differed significantly from measurements in arterial blood (P less than 0.05). BE was the only variable that rendered consistently significant correlations between arterial and arterialized venous blood at each sampling interval. The pooled correlation coefficient between arterial and arterialized venous BE was r = 0.83 [regression equation: BEa = (0.84 BEav)-0.51]. Arterial La was significantly higher than venous La at 1 ME (2.8, 0.7 vs 0.8, 0.3 mmol.l-1) and higher than both venous and arterialized venous La at EE.(ABSTRACT TRUNCATED AT 250 WORDS)     

Metabolism of phenols by Ochromonas danica

Abstract This study investigated the catabolic potential of a eukaryotic alga to degrade one of the most common organic pollutants, phenol. The alga, Ochromonas danica (993/28), was selected for study after screening for its heterotrophic capabilities. The catabolic versatility of the alga was elucidated by incubating with a variety of phenolic compounds. The alga removed phenol, all the cresol isomers and 3,4-xylenol from its incubation media, with phenol being removed more rapidly than any of its methylated homologues. Consequently, the alga was found to have a greater specificity for phenol than for o - or p -cresols. This study shows that O. danica could catabolize phenol and its methylated homologues.     

Indication of dynamic neurovascular coupling from inconsistency between EEG and fMRI indices across sleep–wake states

Sleep and Biological Rhythms - Neurovascular coupling (NVC), the transient regional hyperemia following the evoked neuronal responses, is the basis of blood oxygenation level-dependent techniques...     

Promoting Smoke-Free Homes: A Novel Behavioral Intervention Using Real-Time Audio-Visual Feedback on Airborne Particle Levels

Interventions are needed to protect the health of children who live with smokers. We pilot-tested a real-time intervention for promoting behavior change in homes that reduces second hand tobacco smoke (SHS) levels. The intervention uses a monitor and feedback system to provide immediate auditory and visual signals triggered at defined thresholds of fine particle concentration. Dynamic graphs of real-time particle levels are also shown on a computer screen. We experimentally evaluated the system, field-tested it in homes with smokers, and conducted focus groups to obtain general opinions. Laboratory tests of the monitor demonstrated SHS sensitivity, stability, precision equivalent to at least 1 µg/m³, and low noise. A linear relationship (R² = 0.98) was observed between the monitor and average SHS mass concentrations up to 150 µg/m³. Focus groups and interviews with intervention participants showed in-home use to be acceptable and feasible. The intervention was evaluated in 3 homes with combined baseline and intervention periods lasting 9 to 15 full days. Two families modified their behavior by opening windows or doors, smoking outdoors, or smoking less. We observed evidence of lower SHS levels in these homes. The remaining household voiced reluctance to changing their smoking activity and did not exhibit lower SHS levels in main smoking areas or clear behavior change; however, family members expressed receptivity to smoking outdoors. This study established the feasibility of the real-time intervention, laying the groundwork for controlled trials with larger sample sizes. Visual and auditory cues may prompt family members to take immediate action to reduce SHS levels. Dynamic graphs of SHS levels may help families make decisions about specific mitigation approaches.     

Comparing the use of leaf and cambium tissue in a single genetic study of tropical trees

Amplified fragment length polymorphisms (AFLPs) are a useful molecular tool for studying species with little available genetic information; however, since universal primers are used contaminant DNA from non-target organisms may also be amplified. Cambium tissue may contain fewer biotic contaminants or plant defense chemicals, than the more commonly used leaf tissue, and therefore be more suitable for use as a source of DNA when using universal primers. On the other hand, cambium tissue can be difficult to identify, yields low DNA and requires the bark of the tree to be damaged, thereby increasing the risk of introducing disease. We show that within two tropical tree species, there are few differences between AFLP profiles obtained from either cambium or leaf tissue from the same tree. We studied 50 Brosimum alicastrum individuals at 119 AFLP loci and 40 Swietenia macrophylla individuals at 112 AFLP loci. The matrix of S?rensen similarity indices between individual AFLP profiles for cambium samples was strongly correlated to the matrix for leaf samples in each species (Mantel test; B. alicastrum r = 0.815, P < 0.001; S. macrophylla r = 0.895, P < 0.001). The phylogenetic relationship between the trees studied did not differ dependent on tissue type used and therefore shows that both tissues can be used within a single study without introducing substantial error.