Assessing the variation in the load that produces maximal upper-body power

Substantial variation in the load that produces maximal power has been reported. It has been suggested that the variation observed may be due to differences in subject physical characteristics. Therefore the aim of this study was to determine the extent in which anthropometric measures correlate to the load that produces maximal power. Anthropometric measures (upper-arm length, forearm length, total arm length, upper-arm girth) and bench press strength were assessed in 26 professional rugby union players. Peak power was then determined in the bench press throw exercise using loads of 20 to 60% of one repetition maximum (1RM) in the bench press exercise. Maximal power occurred at 30 +/- 14 %1RM (mean +/- SD). Upper-arm length had the highest correlation with the load maximizing power: -0.61 (90% confidence limits -0.35 to -0.78), implying loads of 22 vs. 38 %1RM maximize power for players with typically long vs. short upper-arm length. Correlations for forearm length, total arm length and upper-arm girth to the load that maximized power were -0.29 (0.04 to -0.57), -0.56 (-0.28 to -0.75), and -0.29 (0.04 to -0.57), respectively. The relationship between 1RM and the load that produced maximal power was r = -0.23 (0.10 to -0.52). The between-subject variation in the load that maximised power observed (SD= +/- 14 %1RM) may have been due to differences in anthropometric characteristics, and absolute strength and power outputs. Indeed, athletes with longer limbs and larger girths, and greater maximal strength and power outputs utilised a lower percentage of 1RM loads to achieve maximum power. Therefore, we recommend individual assessment of the load that maximizes power output

Flow compressibility effects around an open-wheel racing car

A numerical investigation has been conducted into the influence of flow compressibility effects around an open-wheeled racing car. A geometry was created to comply with 2012 F1 regulations. Incompressible and compressible CFD simulations were compared-firstly with models which maintained Reynolds number as Mach number increased, and secondly allowing Mach number and Reynolds number to increase together as they would on track. Results demonstrated significant changes to predicted aerodynamic performance even below Mach 0·15. While the full car coefficients differed by a few percent, individual components (particularly the rear wheels and the floor/ diffuser area) showed discrepancies of over 10% at higher Mach numbers when compressible and incompressible predictions were compared. Components in close ground proximity were most affected due to the ground effect. The additional computational expense required for the more physically-realistic compressible simulations would therefore be an additional consideration when seeking to obtain maximum accuracy even at low freestream Mach numbers

Morality, responsibility and risk: Gay men and proximity to HIV

No abstract available

Reconstructing a Hopeful Theology in the Context of Evolutionary Ethics

The purpose of this thesis is to articulate a theological metaethic which accepts the nature of ethics as understood under the rubric of evolutionary theory. It will be argued that such a theological methaethic can be interpreted as hopeful and optimistic given the apparent evolution of the moral from the amoral. The relationship between theology and evolutionary theory is presented here not as dichotomic but as dialectic – this is not to suggest that the two fields are mutually communicative, but rather that both can contribute to a cohesive, overarching worldview. In this respect, this thesis threads together the theological presupposition of a God of values with the naturalistic and material presuppositions of the modern scientific worldview (being cognizant of the fact that science may not necessarily be presented with these presuppositions). This dialectic occurs between two different but intertwined levels. One is the level of ethical systems; in this work, a particular understanding of Western Christian ethics. This level is framed by another, broader level of metaethics; in this thesis, an overarching understanding of the character of ethics will emerge from reflections on evolutionary theory and its naturalistic context. This will be a naturalistic view, though one which is understood to fit within a theological framework.Religious Studie

Evolution of smart devices and human movement apps: Recommendations for use in sports science education and practice

Many smart phones and tablets possess high-speed cameras. An increasing number of human movement professionals (e.g. personal trainers, athletics coaches, strength and conditioning coaches and physiotherapists) are beginning to use human movement analysis apps with their smart phones/tablets to quantitatively assess their clients’ performance and injury risk. However, an understanding of the validity and reliability of these tools is required. This narrative review seeks to list some relevant human movement apps; summarise the validity and reliability of selected apps and to provide recommendations for their use ineducation and practice

INVESTIGATING THE USE OF SAMPLE ENTROPY TO DETECT FATIGUE

Sample entropy can sensitively identify changes in biological signal regularity. The aim of this study was to investigate whether sample entropy could detect such change in human movement which may be attributable to fatigue or other factors. The regularity of kettlebell trajectories from simulated kettlebell sport competition performed by five experienced lifters was assessed using a novel moving window technique. Resultant entropy estimate trajectories indicate sensitivity to changes in regularity. Decrements in grip strength indicate this may be attributable to fatigue though other possibilities exist. The ability to easily model the resultant entropy trajectories is also demonstrated. The technique holds potential for use by practitioners though more work is required before implementation

Dose and life stage-dependent effects of dietary beta-carotene supplementation on the growth and development of the Booroolong frog

Carotenoids are known for their antioxidant capacity and are considered to play an important role in vertebrate growth and development. However, evidence for their beneficial effects remains limited, possibly because very few studies have tested for dose effects across different life stages. The present study investigated the effect of various doses of dietary beta-carotene supplements on the growth and development of larval and post-metamorphic Booroolong frogs (Litoria booroolongensis). Larval and post-metamorphic basal diets (containing 0.015 and 0.005 mg g−1 total carotenoids, respectively) were supplemented with beta-carotene at one of four concentrations: 0 mg g−1 , 0.1 mg g−1 , 1 mg g−1 and 10 mg g−1 . Each treatment included 72 replicate individuals, and individuals remained on the same diet treatment over both life stages (spanning 53 experimental weeks). Our results show that larvae receiving an intermediate (1 mg g−1 ) beta-carotene supplement dose grew faster than unsupplemented larvae (0 mg g−1 ), and metamorphosed earlier. After metamorphosis, there was no effect of the lowest supplement dose (0.1 mg g−1 ) on growth and development. However, juveniles fed the highest supplement dose (10 mg g−1 ) displayed significantly smaller body mass and lower body condition, compared to all other supplement doses, from 4-months through to sexual maturity (7-months). These findings indicate that beta-carotene supplementation has positive effects on growth and development, but only at intermediate doses, and only in the larval life stage. This knowledge may assist with amphibian conservation by expediting the rate that metamorphs can be generated in captive breeding programmes. More broadly, this is the first study to demonstrate both dose and life stagedependent effects of dietary beta-carotene supplementation on vertebrate growth and development