Recommendations for improved data processing from expired gas analysis indirect calorimetry

There is currently no universally recommended and accepted method of data processing within the science of indirect calorimetry for either mixing chamber or breath-by-breath systems of expired gas analysis. Exercise physiologists were first surveyed to determine methods used to process oxygen consumption ([OV0312]O 2) data, and current attitudes to data processing within the science of indirect calorimetry. Breath-by-breath datasets obtained from indirect calorimetry during incremental exercise were then used to demonstrate the consequences of commonly used time, breath and digital filter post-acquisition data processing strategies. Assessment of the variability in breath-by-breath data was determined using multiple regression based on the independent variables ventilation (VE), and the expired gas fractions for oxygen and carbon dioxide, FEO 2 and FECO2, respectively. Based on the results of explanation of variance of the breath-by-breath [OV0312]O2 data, methods of processing to remove variability were proposed for time-averaged, breath-averaged and digital filter applications. Among exercise physiologists, the strategy used to remove the variability in sequential [OV0312]O2 measurements varied widely, and consisted of time averages (30 sec [38%], 60 sec [18%], 20 sec [11%], 15 sec [8%]), a moving average of five to 11 breaths (10%), and the middle five of seven breaths (7%). Most respondents indicated that they used multiple criteria to establish maximum [OV0312]O 2 ([OV0312]O2max) including: the attainment of age-predicted maximum heart rate (HRmax) [53%], respiratory exchange ratio (RER) >1.10 (49%) or RER >1.15 (27%) and a rating of perceived exertion (RPE) of >17, 18 or 19 (20%). The reasons stated for these strategies included their own beliefs (32%), what they were taught (26%), what they read in research articles (22%), tradition (13%) and the influence of their colleagues (7%). The combination of VE, FEO 2 and FECO2 removed 96-98% of [OV0312]O2 breath-by-breath variability in incremental and steady-state exercise [OV0312]O2 data sets, respectively. Correction of residual error in [OV0312]O2 datasets to 10% of the raw variability results from application of a 30-second time average, 15-breath running average, or a 0.04 Hz low cut-off digital filter. Thus, we recommend that once these data processing strategies are used, the peak or maximal value becomes the highest processed datapoint. Exercise physiologists need to agree on, and continually refine through empirical research, a consistent process for analysing data from indirect calorimetry.

Self-regulation and the intention behaviour gap. Exploring dietary behaviours in university students

The aim of this study was to explore whether two aspects of self-regulation (impulsivity and temporal orientation) could reduce the intention–behaviour gap for two dietary behaviours: fruit and vegetable consumption and saturated fat consumption. Australian undergraduate students (N = 154) completed questionnaires (the Barratt impulsiveness scale and the consideration of future consequences scale) and intention measures, and 1 week later behaviour was measured using the Block rapid food screener. After controlling for demographics, intention was associated with fruit and vegetable consumption, but the self-regulation measures did not further improve the variance accounted for. For saturated fat, gender was associated with consumption, such that males tended to consume more saturated fat. Intention was significantly associated with consumption, and impulsivity further improved the model such that those who were more impulsive tended to consume more saturated fat. These findings suggest that health protective and health risk behaviours, such as those investigated in the current study, may have different determinants.

Does school suspension affect subsequent youth non-violent antisocial behaviour? A longitudinal study of studnets in Victoria, Australia and Washington State, United States

School suspension has been not only associated with negative behaviours but also is predictive of future poor outcomes. The current study investigates (1) whether school suspension is a unique predictor of youth non-violent antisocial behaviour (NVAB) relative to other established predictors, and (2) whether the predictors of NVAB are similar in Australia and the United States (USA). The data analysed here draw on two statewide representative samples of Grade 7 and 9 students in Victoria, Australia and Washington State, USA, resurveyed at 12-month follow-up (N = 3,677, 99% retention). School suspension did not uniquely predict NVAB in the final model. The predictors of NVAB, similar across states, included previous student NVAB, current alcohol and tobacco use, poor family management, association with antisocial friends, and low commitment to school. An implication of the findings is that US evidence-based prevention programmes targeting the influences investigated here could be trialled in Australia.

Visionnaire 2013

Visionnaire: a screening of graduate and masters short films: Wolf, Shaw, Mawrgan. Treasure, Horton, Kyle. Descent, Coughlin, Michael. Cut, Hendriks, Frouwke. A Silent Waltz, Lefoe, Kelsey; Elliott, Isaac; Nanayakkara, Ashini; Tillett, Michael; Teychenne, Danielle; Axiaq, Christopher. Siren, Brander, Dale; Heath, Katherine, Stielow, Rebecca; Bellamy, Edward; Boldeman, Emma; Dong, Jing. The Man Who Cared Too Much, Milner, Robert; Di Quinzio, Carl; Lancaster, Tabitha; Hennequin, Blake; Pinnock, Alicia; Hay, Sarah. Perspective, Hampson, Matt; Gubieski, Alex; Lam, Yen; Jokomo, Nyasha; Carew, Keanan; Burr, Harrison. A Cut Above, Giebler, Heather; Blythe, Carolyn, Carell, Eden; Lai, Cyrus; Rattenbury, Todd; Gatsios, Isaac. Pumpkins, Davies, Brooke; Scharf, Harrison; Jayawardena, Kevin; Lee, Sebastian; Haidari, Ali; Morris, Travis. The Runner, Mitchinson, Liz; Kelly, Rhin; Fomin, Nina; Luxa, Haili; Williams-Pate, Robert; Karoutsos, Antonios. Doors, Sadeghi, Sam; Ward, Ben; Thomson, Alana; Brown, Sam; Earl, Richard; Watterson, James. Daddy’s Little Girl, Dahlenburg, Zoe; Atalla, Joanna; McConnell, Adam; Perri, Tim; Turnbull, Sophie; Leszczynski, Dale. Hopscotch, Egenes, Silge Vikor; Burns, Matt; Fuller, Kelly; Wurm, Christopher; Parker, Stephen; Carson, Brooke Aung.

Lateral positioning for critically ill adult patients: a systematic review

A systematic review was undertaken to evaluate the effect of lateral positioning compared to other body positions on morbidity, mortality, and clinical adverse events for critically ill patients. Twenty three studies met the criteria. Hypoxaemia was not consistently reported. No clinical practice recommendations could be drawn from the included studies due to methodological shortcomings.

Greater effect of diet than exercise training on the fatty acid profile of rat skeletal muscle

We determined the interaction of diet and exercise-training intensity on membrane phospholipid fatty acid (FA) composition in skeletal muscle from 36 female Sprague-Dawley rats. Animals were randomly divided into one of two dietary conditions: high-carbohydrate (64.0% carbohydrate by energy, n = 18) or high fat (78.1% fat by energy, n = 18). Rats in each diet condition were then allocated to one of three subgroups: control, which performed no exercise training; low-intensity (8 m/min) treadmill run training; or high-intensity (28 m/min) run training. All exercise-trained rats ran 1,000 m/session, 4 days/wk for 8 wk and were killed 48 h after the last training bout. Membrane phospholipids were extracted, and FA composition was determined in the red and white vastus lateralis muscles, Diet exerted a major influence on phospholipid FA composition, with the high-fat diet being associated with a significantly (P < 0.01) elevated ratio of n-6/n-3 FA for both red (2.7-3.2 vs. 1.0-1.1) and white vastus lateralis muscle (2.5-2.9 vs. 1.2). In contrast, alterations in FA composition as a result of either exercise-training protocol were only minor in comparison. We conclude that, under the present experimental conditions, a change in the macronutrient content of the diet was a more potent modulator of skeletal muscle membrane phospholipid FA composition compared with either low- or high-intensity treadmill exercise training.

Reasoned versus reactive prediction of behaviour: a meta-analysis of the prototype willingness model

The prototype willingness model (PWM) was designed to extend expectancy-value models of health behaviour by also including a heuristic, or social reactive pathway, to better explain health-risk behaviours in adolescents and young adults. The pathway includes prototype, i.e., images of a typical person who engages in a behaviour, and willingness to engage in behaviour. The current study describes a meta-analysis of predictive research using the PWM and explores the role of the heuristic pathway and intentions in predicting behaviour. Eighty-one studies met inclusion criteria. Overall, the PWM was supported and explained 20.5% of the variance in behaviour. Willingness explained 4.9% of the variance in behaviour over and above intention, although intention tended to be more strongly related to behaviour than was willingness. The strength of the PWM relationships tended to vary according to the behaviour being tested, with alcohol consumption being the behaviour best explained. Age was also an important moderator, and, as expected, PWM behaviour was best accounted for within adolescent samples. Results were heterogeneous even after moderators were taken into consideration. This meta-analysis provides support for the PWM and may be used to inform future interventions that can be tailored for at-risk populations.

Adolescent predictors and environmental correlates of young adult alcohol use problems

To examine the rates of young adult alcohol and drug use and alcohol problems, adolescent predictors of young adult alcohol problems and correlations with young adult social, work and recreational environments.

Food hygiene knowledge in adolescents and young adults

Purpose – The purpose of this paper is to utilise the comprehensive Food Safety Knowledge Instrument to compare food hygiene knowledge across a population of high school and university students in Australia and the UK. Design/methodology/approach – In total, 475 students from secondary schools and universities in Australia and the UK took part in a survey, which included a Food Safety Knowledge Instrument and demographic items. Findings – Food safety knowledge was generally very low. High school students had a mean score of only 38 per cent, while university students just reached a “pass” with a mean of 54 per cent. Demographics accounted for 41 per cent of variance in food knowledge scores. Female gender, being at university rather than high school, and living out of home rather than with parents were associated with greater food knowledge. Residing in Australia rather than the UK and being older were also associated with greater knowledge; however, these findings were subsumed by education group. Socio-economic status was not a significant predictor of food knowledge. Practical implications – Identifying demographic and cultural differences in food knowledge can help to identify at-risk populations to better target in theory and knowledge-based interventions. Originality/value – This study is the first to apply the knowledge instrument in an Australian population. Understanding the baseline knowledge in this population is an important first step at developing effective interventions for food safety.