Acute effects of advertisements on children's choices, preferences, and ratings of liking for physical activities and sedentary behaviours : a randomised controlled pilot study

The acute decision prompting effects of social marketing via television (TV) advertisements promoting physical activity to children are unknown. This pilot study aimed to determine the acute effects of an Australian government-sponsored TV advertisement (called ‘Get Moving’), promoting more physical activity and less sedentary behaviour, on children's choices, preferences, and ratings of liking for physical activities and sedentary behaviours. Thirty-one children aged 10–12 years were recruited from a single public school, and randomised to one of two treatment groups or two control groups (Solomon four-group design). Treatment participants watched an episode of The Simpsons® embedded every 10 min with three 30 s Get Moving advertisements plus standard advertisements. Control participants watched the same episode plus standard advertisements, but without the Get Moving advertisements. The following dependent variables were assessed immediately before and/or after exposure: activity preference (participants selected either verbally or by pointing to one of eight picture cards depicting four physical activities and four sedentary behaviours); ratings of liking (participants rated how much they liked or disliked each of these activities/behaviours either verbally or by pointing to one of nine values with an adjacent smile or frown on a Likert-type scale); and time spent in physical activities was assessed by direct observation during a 10 min free-time session. No significant effects or trends were seen for any of the dependent variables. Further research is needed to determine whether different content and/or higher doses of exposure to physical activity promoting advertisements are needed to influence children's activity choices.

Children's perceptions of the use of public open spaces for active free-play

Activity performed by children in their free-time may have a significant impact on overall physical activity levels, however, very little is known about the influences on children's active free-play. To examine the role and use of public open spaces, 132 children (6-12 years) from a selection of primary schools participated in small focus group interviews. Children reported that their use of public open spaces was influenced by a combination of intrapersonal, social and environmental factors including; the play equipment and facilities at local parks, lack of independent mobility, urban design features, presence of friends, and personal motivation.

An investigation of the influences on children's active free-play

This research examined the influences on children's (6-12 years) active free-play. The findings suggest that there are a number of strategies that focus on individual, social and physical environmental factors that have the potential to be successful in creating opportunities for children to be physically active in their free-time.

Cues and the optimal timing of activities under environmental changes

Organisms time activities by using environmental cues to forecast the future availability of important resources. Presently, there is limited understanding of the relationships between cues and optimal timing, and especially about how this relationship will be affected by environmental changes. We develop a general model to explore the relation between a cue and the optimal timing of an important life history activity. The model quantifies the fitness loss for organisms failing to time behaviours optimally. We decompose the immediate change in fitness resulting from environmental changes into a component that is due to changes in the predictive power of the cue and a component that derives from the mismatch of the old response to the cue to the new environmental conditions. Our results show that consequences may range from negative, neutral to positive and are highly dependent on how cue and optimal timing and their relation are specifically affected by environmental changes.

Effect of electronic time monitors on children's television watching: pilot trial of a home-based intervention

OBJECTIVES: This pilot study evaluated the feasibility (recruitment, retention, and acceptability) and preliminary efficacy of a six-week home-based electronic time monitor intervention on New Zealand children's television watching in 2008. METHODS: Twenty-nine children aged 9 to 12 years who watched more than 20 h of television per week (62% male, mean age 10.4 years) were randomised to either the intervention or the control group. The intervention group received an electronic TV time monitor for 6 weeks and advice to restrict TV watching to 1 h per day or less. The control group was given verbal advice to restrict TV watching. RESULTS: Participant retention at 6 weeks was 93%. Semi-structured interviews with intervention families confirmed moderate acceptability of TV time monitors and several perceived benefits including better awareness of household TV viewing and improved time planning. Drawbacks reported included disruption to parents' TV watching and increased sibling conflict. Time spent watching television decreased by 4.2 h (mean change [SD]: -254 [536] min) per week in the intervention group compared with no change in the control group (-3 [241] min), but the difference between groups was not statistically significant, p=0.77. Both groups reported decreases in energy intake from snacks and total screen time and increases in physical activity measured by pedometer and between-group differences were not statistically significant. CONCLUSIONS: Electronic TV time monitors are feasible to use for home-based TV watching interventions although acceptability varies between families. Preliminary findings from this pilot suggest that such devices have potential to decrease children's TV watching but a larger trial is needed to confirm effectiveness. Future research should be family-orientated; take account of other screen time activities; and employ TV time monitors as just one of a range of strategies to decrease sedentary behaviour.

The dietary, physical activity and sedentary behaviours of Victorian regional secondary school students

The aim of this study was to investigate the dietary, physical activity and sedentary behaviours of adolescents from four secondary schools in Warrnambool, regional Victoria. In 2004, a random sample of students (n=712), stratified by school year level, was generated from school enrolment databases and 443 students completed a lifestyle questionnaire. Twenty per cent of students were physically active for 60 minutes or more per day; 28 per cent used electronic media in free time for a maximum of two hours per day. Only seven per cent of students met these two Australian physical activity recommendations. Fruit, vegetables and dairy products were consumed every day by 39 per cent, 40 per cent and 71 per cent of students respectively; three serves per day of each of these foods are recommended for Australian adolescents. Compared with boys, girls were less physically active (p<0.001), consumed more fruit (p=0.011) and vegetables (p<0.001), but fewer dairy products (p<0.024). Seventeen per cent of students were overweight or obese; these students were less physically active than normal weight peers (p<0.018). The dietary, physical and sedentary behaviours of regional Victorian secondary school students in this study were inadequate when compared with Australian recommendations. Dietary and physical activity habits are still evolving in adolescence and unhealthy habits can still be changed.

Politics and technology : friends or enemies of the story?

Taking its cue from the conference at which it was presented, this article considers both old stories and new ways, and addresses the question of the impact not only of new technology but also of politics upon 'the story'. Fundamental is the question of whether politics and technology might be considered friends or enemies of the story. Drawing on her long term experiences as an interviewer, the author interrogates particular oral history projects undertaken into children's play lore and play ways, to show how children's games and play time activities have been politicised. Locating her analysis in an international context of US legislation and British and Australian research, the author examines how play itself has become the plaything of both politicians and fear. She then examines the impact of high fidelity recording equipment and the universal accessibility of material located on the internet to address the question of technology as friend of the story, ultimately concluding that the story and the question will both go on.

The Short Questionnaire to Assess Health-Enhancing (SQUASH) physical activity in adolescents: a validation using doubly labeled water

Accurate assessment of physical activity energy expenditure (PAEE) among adolescents is important for surveillance, evaluating interventions, and understanding the relation between energy balance and normal physiological and behavioral growth and development. The purpose of this study was to examine the validity of the Short Questionnaire to Assess Health-Enhancing Physical Activity (SQUASH)13 for measuring PAEE among adolescents. Methods: The participants were seventeen adolescents (9 females; Mean age = 17.53; SD = 0.62). Energy expenditure was measured during a 9-day period with doubly labeled water (DLW). The SQUASH was self-administered on the morning of the 10th day and assessed commuting activities, leisure time activities, household activities, and activities at work and school over the previous 9 days. Results: A Bland-Altman plot indicated that the SQUASH underestimated PAEE compared with DLW by a mean difference of 126 kcal·d-1 (95% limits of agreement:-1,207 to 1,459 kcal·d-1), representative of a 10% underestimation. The Spearman rank order correlation coefficient showed there was a significant association between the SQUASH and DLW (r =.50, P =.04), for estimating PAEE. Conclusion: When using a sample of highly active adolescents, the SQUASH is a valid self-report tool for measuring PAEE at the group and individual rank order level.

Incorporating differences in marginal utilities of time across activities in a time allocation model

Most existing activity time allocation models assume that individuals allocate their time to different activities over a period in such a way that the marginal utilities of time across activities are equal. Their argument is that, if not equal, an individual is free to allocate more time to those activities whose marginal utilities of time are higher and, finally allocates the optimal time to each activity with equal marginal utility. However, such an ideal situation may not always prevail in reality, especially when an individual is under income constraint and/or under intense time pressure. In order to incorporate such differences in marginal utilities of time across activities, we enrich the traditional activity time allocation model by explicitly including income constraint and by adding marginal extension activity choice model. As an application, the developed integrated model is used to estimate the value of activity time during weekends in Tokyo. The results are encouraging in that they forecast the individual time allocation more accurately and estimate realistically the value of activity time for each activity in a set of different activities than do by existing traditional models.

Individual, social and physical environmental correlates of children's active free-play : a cross-sectional study

Background
Children's unstructured outdoor free-play (or active free-play) has the potential to make an important contribution to children's overall physical activity levels. Limited research has, however, examined physical activity in this domain. This study examined associations between individual, social and physical environmental factors and the frequency with which children play in particular outdoor locations outside school hours. This study also investigated whether the frequency of playing in outdoor locations was associated with children's overall physical activity levels.

Methods
Participants including 8-9 year old children and their parents (n = 187) were recruited from a selection of primary schools of varying socioeconomic status across metropolitan Melbourne, Australia. Parents completed a survey and children's overall physical activity levels were measured by accelerometry. Regression models examined the odds of children playing in various outdoor settings according to particular correlates.

Results
Inverse associations were found between preference for activities not involving physical activity, and the likelihood of children playing in the yard at home on the weekend (OR = 0.65; CI = 0.45,0.95). Positive correlates of children playing in their own street included: parental perceptions that it was safe for their child to play in their street (weekdays [OR = 6.46; CI = 2.84,14.71], weekend days [OR = 6.01; CI = 2.68,13.47]); children having many friends in their neighbourhood (OR = 2.63; CI = 1.21,5.76); and living in a cul-de-sac (weekdays [OR = 3.99; CI = 1.65,9.66], weekend days [OR = 3.49; CI = 1.49,8.16]). Positive correlates of more frequent play in the park/playground on weekdays included family going to the park together on a weekly basis on weekdays (OR = 6.8; CI = 3.4,13.6); and on weekend days (OR = 7.36; CI = 3.6,15.0). No differences in mean mins/day of moderate-vigorous physical activity were found between children in the highest and lowest tertiles for frequency of playing in particular outdoor locations.

Conclusion
The presence of friends, safety issues and aspects of the built environment were reported by parents to be associated with children's active free-play in outdoor locations. Future research needs to further examine associations with time spent in active free-play and objectively-measured overall physical activity levels. It is also important to investigate strategies for developing a supportive social and physical environment that provides opportunities for children to engage in active free-play.

Time-delay systems : design of delay-free and low-order observers

This note provides a comprehensive treatment on the design of functional observers for linear systems having a time-varying delay in the state variables. The designed observers possess attractive features of being low-order and delay-free and hence they are cost effective and easy to implement. Existence conditions are derived and a design procedure for finding low-order observers is given.

The activities and impacts of part-time employment on full time undergraduate students in property and construction courses in Australia

This paper examines the extent of part-time employment of undergraduate students enrolled in property and construction related courses in five universities across Australia. Forty five percent of the students responded to a questionnaire on their part-time work. Past research reveals that there is need for a more accurate understanding as to why students seek part-time work to the extent that they do and that working long hours has a negative effect on the study patterns of undergraduate students. Increased employer work demands results in less time available for study and an inability to attend lectures because of work. There is growing concern that students are increasingly disinterested in connecting with the broader and total university experience and are instead, seeking to adopt a minimalist approach to education.

Analysis of current research for Property and construction students’ results reveals that students are working on average 18 hours per week during semester time. The students therefore appear to be working beyond what is considered beneficial to their studies, although their contextual understanding and work ethic improves.

The paper concludes with some approaches that could re- engage students into the learning process. It may be helpful to develop a partnership between the University and the industry thereby providing work experience that complements the program of study. Otherwise students may not get the range of experience they need and may struggle to find the linkages between theory and practice.

Intelligent clothing for automated recognition of human physical activities in free-living environment

This paper presents an intelligent clothing framework for human daily activity recognition using a single waist-worn tri-axial accelerometer sensor coupled with a robust pattern recognition system. The activity recognition algorithm is realized to distinguish six different physical activities through three major steps: acceleration signal collection/pre-processing, wavelet-based principle component analysis, and a support vector machine classifier. The proposed activity recognition method has been experimentally validated through two batches of trials with an overall mean classification accuracy of 95.25 and 94.87%, respectively. These results suggest that the intelligent clothing is not only able to learn the activity patterns but also capable of generalizing new data from both known and unknown subjects. This enables the proposed intelligent clothing to be applied in a comfortable and in situ assessment of human physical activities, which would open up new market segments to the textile industry.

Effect of selenium-saturated bovine lactoferrin (Se-bLF) on antioxidant enzyme activities in human gut epithelial cells under oxidative stress

Cancer and many chronic inflammatory diseases are associated with increased amounts of reactive oxygen species (ROS). The potential cellular and tissue damage created by ROS has significant impact on many disease and cancer states and natural therapeutics are becoming essential in regulating altered redox states. We have shown recently that iron content is a critical determinant in the antitumour activity of bovine milk lactoferrin (bLF). We found that 100% iron-saturated bLF (Fe-bLF) acts as a potent natural adjuvant and fortifying agent for augmenting cancer chemotherapy and thus has a broad utility in the treatment of cancer. Furthermore, we also studied the effects of iron saturated bLF's ability as an antioxidant in the human epithelial colon cancer cell line HT29, giving insights into the potential of bLF in its different states. Thus, metal saturated bLF could be implemented as anti-cancer neutraceutical. In this regard, we have recently been able to prepare a selenium (Se) saturated form of bLF, being up to 98% saturated. Therefore, the objectives of this study were to determine how oxidative stress induced by hydrogen peroxide (H₂O₂) alters antioxidant enzyme activity within HT29 epithelial colon cancer cells, and observe changes in this activity by treatments with different antioxidants ascorbic acid (AA), Apo (iron free)-bLF and selenium (Se)-bLF. The states of all antioxidant enzymes (glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-s-transferase (GsT), catalase and superoxide dismutase (SOD)) demonstrated high levels within untreated HT29 cells compared to the majority of other treatments being used, even prior to H₂O₂ exposure. All enzymes showed significant alterations in activity when cells were treated with antioxidants AA, Apo-bLF or Se-bLF, with and/or without H₂O₂ exposure. Obvious indications that the Se content of the bLF potentially interacted with the glutathione (GSH)/GPx/GR/GsT associated redox system could be observed immediately, showing capability of Se-bLF being highly beneficial in helping to maintain a balance between the oxidant/antioxidant systems within cells and tissues, especially in selenium deficient systems. In conclusion, the antioxidative defence activity of Se-bLf, investigated in this study for the first time, shows dynamic adaptations that may allow for essential protection from the imbalanced oxidative conditions. Because of its lack of toxicity and the availability of both selenium and bLF in whole milk, Se-bLF offers a promise for a prospective natural dietary supplement, in addition to being an immune system enhancement, or a potential chemopreventive agent for cancers.

Faster and parameter-free discord search in quasi-periodic time series

Time series discord has proven to be a useful concept for time-series anomaly identification. To search for discords, various algorithms have been developed. Most of these algorithms rely on pre-building an index (such as a trie) for subsequences. Users of these algorithms are typically required to choose optimal values for word-length and/or alphabet-size parameters of the index, which are not intuitive. In this paper, we propose an algorithm to directly search for the top-K discords, without the requirement of building an index or tuning external parameters. The algorithm exploits quasi-periodicity present in many time series. For quasi-periodic time series, the algorithm gains significant speedup by reducing the number of calls to the distance function.