Mediators of the effect of the JUMP-in intervention on physical activity and sedentary behavior in Dutch primary schoolchildren from disadvantaged neighborhoods.

<p>Abstract</p> <p>Background</p> <p>Important health benefits can be achieved when physical activity in children from low socio-economic status is promoted and sedentariness is limited. By specifying the mediating mechanisms of existing interventions one can improve future physical activity interventions. This study explored potential mediators of the long-term effect of the school-based multicomponent JUMP-in intervention on sport participation, outdoor play and screen time in Dutch primary schoolchildren from disadvantaged neighborhoods.</p> <p>Methods</p> <p>In total, 600 primary schoolchildren (aged 9.8 ± 0.7, 51% girls, 13% Dutch ethnicity, 35% overweight) from 9 intervention and 10 control schools were included in the analyses. JUMP-in was developed using Intervention Mapping, and targeted psychological and environmental determinants of physical activity. Outcome behaviors were self-reported sport participation, outdoor play, TV-viewing behavior and computer use. Potential mediators were self-reported psychological, social and physical environmental factors.</p> <p>Results</p> <p>JUMP-in was effective in improving sport participation after 20 months, but not in improving outdoor play, or reducing TV-viewing or computer time. JUMP-in was not effective in changing hypothesized mediators so no significant mediated effects could be identified. However, changes in self-efficacy, social support and habit strength were positively associated with changes in sport participation, and changes in social support, self-efficacy, perceived planning skills, enjoyment and habit strength were positively associated with changes in outdoor play. Changes in enjoyment was positively associated with changes in TV-viewing while parental rules were negatively associated. Having a computer in the bedroom and enjoyment were positively associated with changes in computer use, while changes in parental rules were negatively associated.</p> <p>Conclusions</p> <p>Besides a significant positive effect on sports participation, no significant intervention effect on outdoor play, screen time or any of the potential mediators was found. This suggest that other (unmeasured) factors operated as mediating mechanisms of the intervention, that we used unsuccessful intervention strategies, that the strategies were inappropriately implemented, or that children are unable to accurately recall past activities and cognitions. Additionally, the school setting might not be the sole channel to influence leisure time activities. Still, several personal and environmental constructs were found to be relevant in predicting change in sport participation, outdoor play and screen behavior and seem to be potential mediators. Future interventions are recommended including more effective strategies targeting these relevant constructs, addressing different constructs (e.g. pedagogic skills of parents), and focusing on different implementation settings.</p> <p>Trail registration</p> <p>ISRCTN17489378</p

Development of a novel, through-flow microwave-based regenerator for sorbent-based direct air capture

In this work an all-electric regenerator is developed for the desorption of CO2 from air-capture sorbents using microwaves. An electromagnetic model was made for a continuous flow radial desorber and its dimensions were optimised for maximal microwave utilisation. Based on the optimal dimensions an actual prototype, capable of desorbing CO2 from a commercial supported amine sorbent in fixed- or moving-bed configuration was built to demonstrate the concept and to study performance characteristics. TSA experiments using nitrogen as purge gas to produce enriched air (1 to 2 vol.% CO2) were done. Productivities of up to 1.5 kgCO2/kgsorb./d were demonstrated, with a total energy duty of 25 MJ/kgCO2. Compared to traditional TVSA desorption, the energy duty is similar while the productivity is significantly higher. The process can be further improved by creating an even more homogeneous electric field (preventing hot spots in the regenerator) and by enabling desorption under vacuum conditions to produce pure CO2. Overall, microwave desorption is demonstrated as an effective way to circumvent heat transfer limitations present during more traditional thermal desorption processes using polymeric sorbents

Animal behaviour analysis with GPS and 3D accelerometers

A herd of dairy cows were equipped with GPS tracking collars and at the same time, their behaviour was manually scored with Pocket Observer software. TrackLab was used to visualize the data. The manually scored behaviours were used to classify the GPS data, and for foraging, resting and walking, the GPS data had a very high predictive value for the behaviours. Although ruminating and standing could not be distinguished on the basis of GPS data alone, a further experiment on Canada Geese indicated that the addition of accelerometer data to the GPS tags showed very promising results with respect to distinguishing more behaviours than could be classified using GPS alone. This opens up a spectrum of possibilities for farm mangers including automatic detection oestrus in cattle and geofencing applications

Animal behaviour analysis with GPS and 3D accelerometers

A herd of dairy cows were equipped with GPS tracking collars and at the same time, their behaviour was manually scored with Pocket Observer software. TrackLab was used to visualize the data. The manually scored behaviours were used to classify the GPS data, and for foraging, resting and walking, the GPS data had a very high predictive value for the behaviours. Although ruminating and standing could not be distinguished on the basis of GPS data alone, a further experiment on Canada Geese indicated that the addition of accelerometer data to the GPS tags showed very promising results with respect to distinguishing more behaviours than could be classified using GPS alone. This opens up a spectrum of possibilities for farm mangers including automatic detection oestrus in cattle and geofencing applications