Accelerometer data requirements for reliable estimation of habitual physical activity and sedentary time of children during the early years - a worked example following a stepped approach

This study presents a worked example of a stepped process to reliably estimate the habitual physical activity and sedentary time of a sample of young children. A total of 299 children (2.9 ± 0.6 years) were recruited. Outcome variables were daily minutes of total physical activity, sedentary time, moderate to vigorous physical activity and proportional values of each variable. In total, 282 (94%) provided 3 h of accelerometer data on ≥1 day and were included in a 6-step process: Step-1: determine minimum wear-time; Step-2: process 7-day-data; Step-3: determine the inclusion of a weekend day; Step-4: examine day-to-day variability; Step-5: calculate single day intraclass correlation (ICC) (2,1); Step-6: calculate number of days required to reach reliability. Following the process the results were, Step-1: 6 h was estimated as minimum wear-time of a standard day. Step-2: 98 (32%) children had ≥6 h wear on 7 days. Step-3: no differences were found between weekdays and weekend days (P ≥ 0.05). Step-4: no differences were found between day-to-day variability (P ≥ 0.05). Step-5: single day ICC’s (2,1) ranged from 0.48 (total physical activity and sedentary time) to 0.53 (proportion of moderate to vigorous physical activity). Step-6: to reach reliability (ICC = 0.7), 3 days were required for all outcomes. In conclusion following a 7 day wear protocol, ≥6 h on any 3 days was found to have acceptable reliability. The stepped-process offers researchers a method to derive sample-specific wear-time criterion.     

Effects of glucose–fructose versus glucose ingestion on stride characteristics during prolonged treadmill running

Scarce research has examined the effects of carbohydrate composition on running stride characteristics. On two occasions, 14 males and 6 females completed a 120-min sub-maximal run followed by a 4-mile time trial. Participants consumed glucose (GLU) or glucose–fructose (GLU–FRU) beverages supplying 1.3 g/min carbohydrate. Substrate use, psychological affect [Feeling Scale (FS)], and stride characteristics (stride frequency, stride length, and contact time) were assessed. Effects were expressed as Cohen’s d (90% confidence limits [90% CL]). CLs for stride frequency differences at 53 min (90% CL = 0.04–0.21) and 113 min (90% CL = 0.02–0.24) did not cover 0, indicating a positive effect of GLU–FRU. However, effect sizes were small (d = 0.13) and likely-to-very-likely trivial. Energy expenditure differences at sub-maximal end were very likely trivial (d = 0.08; 90% CL = 0.00–0.17), while FS ratings were possibly higher for GLU–FRU at 50 (d = 0.19; 90% CL = ?0.10–0.48) and 110 min (d = 0.16; 90% CL = ?0.13–0.45). During the time trial, stride length was possibly higher with GLU–FRU (d = 0.13; 90% CL = ?0.08–0.33). Glucose–fructose co-ingestion has no significant effect on stride characteristics during constant-velocity running but may result in slightly higher stride length during self-paced running.     

Ordinal position in the serial learning of rats

Rats were runway trained on each of two, three-trial series consisting of different varieties of reward (X, Y, and Z) and nonreward (N) serving as trial outcomes. The two series are represented as XNY and ZNN. Distinguishing the two series were different brightness and texture cues on the runway floor. Transfer tests, conducted after the rats had developed faster running for rewarded trials than for nonrewarded trials and slower running on Trial 2 of ZNN than on Trial 2 of XNY, provided evidence that trial position, rather than item memories, was controlling the discriminations. In Experiment 1, reversing the floor cues completely reversed the discriminations. In Experiment 2, transfer to NNN did not change the routine patterns of approach that had been established.     

The effects of audience reaction shots on attitudes towards controversial issues

This study investigated the influence that audience reaction shots have on viewers’ attitudes towards controversial issues discussed on television. It was hypothesized that viewers would show stronger agreement with a side of an issue which was coupled with positive reaction shots. No evidence was found to support a main effect, but evidence was found to suggest that the effects of reaction shots is contingent on viewers’ beliefs that the audience holds the same position on the issue as they do.     

Examining the accuracy of teachers' judgments of DIBELS performance

The purpose of this investigation was to examine the accuracy of teachers' judgments of students' early literacy skills and to determine if students' achievement levels influenced teachers' judgments. Typical and lower‐achieving kindergarten and first‐grade students' scores on the Nonsense Word Fluency and Phoneme Segmentation Fluency measures of the Dynamic Indicators of Basic Early Literacy Skills (DIBELS) were compared to the predicted performance by their teachers. Results showed a moderately strong correlation between teachers' judgments and students' performance across all of the students, which is consistent with past research. Teachers' judgments, however, consistently and significantly overestimated the actual performance of students, particularly those who were typically performing students. The findings of the investigation suggest that relying on teachers' judgments of students' early literacy skills alone may be insufficient to accurately identify students at risk for reading difficulties. © 2011 Wiley Periodicals, Inc.     

Mixed-method pre-cooling reduces physiological demand without improving performance of medium-fast bowling in the heat

This study examined physiological and performance effects of pre-cooling on medium-fast bowling in the heat. Ten, medium-fast bowlers completed two randomised trials involving either cooling (mixed-methods) or control (no cooling) interventions before a 6-over bowling spell in 31.9±2.1°C and 63.5±9.3% relative humidity. Measures included bowling performance (ball speed, accuracy and run-up speeds), physical characteristics (global positioning system monitoring and counter-movement jump height), physiological (heart rate, core temperature, skin temperature and sweat loss), biochemical (serum concentrations of damage, stress and inflammation) and perceptual variables (perceived exertion and thermal sensation). Mean ball speed (114.5±7.1 vs. 114.1±7.2 km · h(-1); P = 0.63; d = 0.09), accuracy (43.1±10.6 vs. 44.2±12.5 AU; P = 0.76; d = 0.14) and total run-up speed (19.1±4.1 vs. 19.3±3.8 km · h(-1); P = 0.66; d = 0.06) did not differ between pre-cooling and control respectively; however 20-m sprint speed between overs was 5.9±7.3% greater at Over 4 after pre-cooling (P = 0.03; d = 0.75). Pre-cooling reduced skin temperature after the intervention period (P = 0.006; d = 2.28), core temperature and pre-over heart rates throughout (P = 0.01-0.04; d = 0.96-1.74) and sweat loss by 0.4±0.3 kg (P = 0.01; d = 0.34). Mean rating of perceived exertion and thermal sensation were lower during pre-cooling trials (P = 0.004-0.03; d = 0.77-3.13). Despite no observed improvement in bowling performance, pre-cooling maintained between-over sprint speeds and blunted physiological and perceptual demands to ease the thermoregulatory demands of medium-fast bowling in hot conditions.     

An administrative mess: A case study from the officiating community

This case is written for instructors of classes focused on strategic management, organisational behaviour, human resource management, and/or an officiating course. The case highlights the numerous administrative processes a new employee in a sport organisation would face. Although the case is fictional it is based on the authors’ personal and professional experiences in athletics administration and officiating, and further draws upon the authors’ research in the area of officiating. Consequently, this case study was constructed based on first-hand observation, interviews and conversation with numerous officials and administrators, and through the examination of documents frequently used to manage officials. As a result, the case provides an opportunity for students to critically evaluate and address: (1) a sport organisation's policies and procedures; (2) issues related to human resource management within a sport setting; (3) the managerial response after an organisational failure.     

Defining Quality Child Care: Multiple Stakeholder Perspectives

Multiple perspectives regarding the definition of quality child care, and how child care quality can be improved, were examined using a focus group methodology. Participants were representatives from stakeholder groups in the child care profession, including child care center owners and directors (3 groups), parents (3 groups), child caregivers (3 groups), policy makers (1 group), and social service providers (1 group). Qualitative analysis revealed 6 components of quality that were consistently discussed across all participant groups: (a) communication and rapport, (b) caregiver practices, (c) staff characteristics, (d) finances and resources, (e) visibility and involvement, and (f) professionalism. Analyses highlighted differences among stakeholder groups and the complex interplay among quality components. Findings are compared to previously documented perspectives on child care quality, and a conceptual model is presented that (a) summarizes findings about how proximity to child impacts definitions of quality and (b) highlights the central role played by child care center directors. Implications for child care practice and policy are discussed.