Validity and Reliability of Proximity Detection with Bluetooth-Enabled Accelerometers among Adults

ABSTRACT

Introduction: This study examined the concurrent validity and inter-pair reliability of the proximity detection function on Bluetooth-enabled accelerometers across manufacturer-specified ranges. If valid, this method could be used for objectively measuring shared physical activity participation. Method: Thirty-six dyads aged 21.6 (2.1) years wore two sets of Bluetooth-enabled accelerometers initialized as beacons and receivers to compare accelerometer-measured proximity detection to direct observation under 11 different controlled and free-living conditions. Results: The proportion of minutes in which proximity was detected differed across conditions (p < .001), with the highest proportions in the controlled conditions (.77–1.0). Among the free-living conditions, the different room (.73 ± .20) condition had the highest proximity detection proportions. There were no differences in the proximity detection across accelerometer pairs (p = .265). Conclusion: Proximity detection with Bluetooth-enabled accelerometers was reliable and had the highest detection rates under the controlled treadmill walking conditions. Despite limitations, using Bluetooth-enabled accelerometers is a promising approach for measuring shared physical activity.     

Hydration, sweat and thermoregulatory responses to professional football training in the heat

AbstThis study examined the relationship between intensity of training and changes in hydration status, core temperature, sweat rate and composition and fluid balance in professional football players training in the heat. Thirteen professional football players completed three training sessions; "higher-intensity" (140 min; HI140), "lower-intensity" (120 min; LI120) and "game-simulation" (100 min; GS100). Movement demands were measured by Global Positioning System, sweat rate and concentration were determined from dermal patches and body mass change. Despite similar environmental conditions (26.9 ± 0.1 °C and 65.0 ± 7.0% relative humidity [Rh]), higher relative speeds (m · min(-1)) and increased perceptions of effort and thermal strain were observed in HI140 and GS100 compared with LI120 (P < 0.05). Significantly (P < 0.05) greater sweat rate (L · h(-1)) and electrolyte losses (g) were observed in HI140 and GS100 compared with LI120. Rate of rise in core temperature was correlated with mean speed (r = 0.85), session rating of perceived exertion (sRPE) (r = 0.61), loss of potassium (K+) (r = 0.51) sweat rate (r = 0.49), and total sweat loss (r = 0.53), with mean speed the strongest predictor. Sodium (Na+) (r = 0.39) and K+ (r = 0.50) losses were associated with total distance covered. In hot conditions, individualised rehydration practices should be adopted following football training to account for differences in sweat rate and electrolyte losses in response to intensity and overall activity within a session.     

Ranking of rankings: benchmarking twenty-five higher education ranking systems in Europe

The purpose of this study is to evaluate the ranking practices of 25 European higher education ranking systems (HERSs). Ranking practices were assessed with 14 quantitative measures derived from the Berlin Principles on Ranking of Higher Education Institutions (BPs). HERSs were then ranked according to their degree of congruence with the BPs. Additionally, the three domains of methodology, transparency, and consumer-friendliness were proposed to underlie the BPs, and the measures were also applied for assessing HERSs regarding these domains. Results indicate that the cooperating HERSs by CHE (Germany), AQA (Austria) and swissUp (Switzerland) exhibit the highest congruence with the BPs. However, no European HERS demonstrates good overall congruence with the BPs, mainly due to methodological shortcomings. Results further show that HERSs compiled and published by non-profit research entities seem to perform better than the majority of HERSs published by for-profit news outlets. International comparisons indicate that HERSs published in German-speaking countries and the Netherlands tend to exhibit a higher congruence with the BPs. Overall, this study hopes to stimulate the improvement of ranking practices through benchmarking with existing exemplary models. The quantitative assessment tool further promises to be useful in explaining relative stability or change of higher education institutions in HERSs, as well as in helping to explain resource allocation pressures within higher education institutions.     

Determining the business impact of knowledge management

This case study describes an evaluation of business impact and return on investment (ROI) for the Knowledge Exchange, a knowledge management (KM) system within Accenture. The evaluation used a continuous measurement design to allow impact and ROI to be tracked across time and groups. The results demonstrated a significant positive impact on productivity, based largely on the effect on time savings realized by leveraging a useful KM system across a large population of employees.     

Heart rate,blood lactate concentration and estimated energy expenditure in a semi-professional rugby league team during a match: a case study

The aim of this study was to examine heart rate, blood lactate concentration and estimated energy expenditure during a competitive rugby league match. Seventeen well-trained rugby league players (age, 23.9 +/- 4.1 years; VO2max, 57.9 +/- 3.6 ml x kg(-1) x min(-1); height, 1.82 +/- 0.06 m; body mass, 90.2 +/- 9.6 kg; mean +/- s) participated in the study. Heart rate was recorded continuously throughout the match using Polar Vantage NV recordable heart rate monitors. Blood lactate samples (n = 102) were taken before the match, after the warm-up, at random stoppages in play, at half time and immediately after the match. Estimated energy expenditure during the match was calculated from the heart rate-VO2 relationship determined in laboratory tests. The mean team heart rate (n = 15) was not significantly different between halves (167 +/- 9 vs 165 +/- 11 beats x min(-1)). Mean match intensity was 81.1 +/- 5.8% VO2max. Mean match blood lactate concentration was 7.2 +/- 2.5 mmol x l(-1), with concentrations for the first half (8.4 +/- 1.8 mmol x l(-1)) being significantly higher than those for the second half (5.9 +/- 2.5 mmol x l(-1)) (P<0.05). Energy expenditure was approximately 7.9 MJ. These results demonstrate that semi-professional rugby league is a highly aerobic game with a considerable anaerobic component requiring high lactate tolerance. Training programmes should reflect these demands placed on players during competitive match-play.     

Does Interpretive Test Score Information Help Teachers?

To what extent do teachers possess the competence to interpret state testing program results properly?     

Journals at bepress: new twists on an old model

In recent years academic journal publishers have explored a variety of new business models. The Berkeley Electronic Press (bepress), founded by professors in 1999, now publishes 39 electronic‐only journals. bepress's own model rests on three principles: improve, but do not break, the traditional journal; allow non‐subscribers to read articles as guests; and offer reasonable and sustainable prices to libraries. This model has resulted in steady growth. Even in the shifting landscape of open access, there remains a place for professional journal publishers who offer innovative improvements, traditionally qualified content, and reasonable prices.     

Cognitive Techniques as a Means for Facilitating Supervisee Development

During periods of uncertainty or psychological distress, a supervisee may encounter or develop rigid or unhelpful thinking patterns that could delay development by promoting discouraging realities and experiences. Such cognitive experiences often are so subtle that they occur outside of the supervisee's immediate awareness. This article explores how the cognitive model of counseling could be used in supervision as a guide to help the supervisor and supervisee discover and modify negative thought processes.