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Maloney, S. J. (2019). The Relationship Between Asymmetry and Athletic Performance: A Critical Review. The Journal of Strength & Conditioning Research, 33(9).
Abstract: Maloney, SJ. The relationship between asymmetry and athletic performance: A critical review. J Strength Cond Res 33(9): 2579-2593, 2019--Symmetry may be defined as the quality to demonstrate an exact correspondence of size, shape, and form when split along a given axis. Although it has been widely asserted that the bilateral asymmetries are detrimental to athletic performance, research does not wholly support such an association. Moreover, the research rarely seeks to distinguish between different types of bilateral asymmetry. Fluctuating asymmetries describe bilateral differences in anthropometric attributes, such as nostril width and ear size, and are thought to represent the developmental stability of an organism. There is evidence to suggest that fluctuating asymmetries may be related to impaired athletic performance, although contradictory findings have been reported. Sporting asymmetries is a term that may better describe bilateral differences in parameters, such as force output or jump height. These asymmetries are likely to be a function of limb dominance and magnified by long-standing participation within sport. Sporting asymmetries do not seem to carry a clear influence on athletic performance measures. Given the vast discrepancy in the methodologies used by different investigations, further research is warranted. Recent investigations have demonstrated that training interventions can reduce sporting asymmetries and improve performance. However, studies have not sought to determine whether the influence of sporting asymmetry is independent of improvements in neuromuscular parameters. It may be hypothesized that the deficient (weaker) limb has a greater potential for adaptation in comparison to the strong limb and may demonstrate greater responsiveness to training.
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Nelson, X. J., & Fijn, N. (2013). The use of visual media as a tool for investigating animal behaviour. Animal Behaviour, 85(3), 525–536.
Abstract: In this essay we outline how video-related technology can be used as a tool for studying animal behaviour. We review particular aspects of novel, innovative animal behaviour uploaded by the general public via video-based media on the internet (using YouTube as a specific example). The behaviour of animals, particularly the play behaviour focused on here, is viewed by huge audiences. In this essay we focused on three different kinds of media clips: (1) interspecies play between dogs and a range of other species; (2) object play in horses; and (3) animal responses to stimuli presented on iPads, iPods and iPhones. We argue that the use of video is a good means of capturing uncommon or previously unknown behaviour, providing evidence that these behaviours occur. Furthermore, some of the behaviours featured on YouTube provide valuable insights for future directions in animal behaviour research. If we also take this opportunity to convey our knowledge to a public that seems to be fundamentally interested in animal behaviour, this is a good means of bridging the gap between knowledge among an academic few and the general public.
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Whitehead, H. (2008). Precision and power in the analysis of social structure using associations. Anim. Behav., 75(3), 1093–1099.
Abstract: I develop guidelines for assessing the precision and power of statistical techniques that are frequently used to study nonhuman social systems using observed dyadic associations. Association indexes estimate the proportion of time that two individuals are associated. Binomial approximation and nonparametric bootstrap methods produce similar estimates of the precision of association indexes. For a mid-range (0.4-0.9) association index to have a standard error of less than 0.1 requires about 15 observations of the pair associated, and for it to be less than 0.05, this rises to 50 observations. The coefficient of variation among dyads of the proportion of time that pairs of individuals are actually associated describes social differentiation (S), and this may be estimated from association data using maximum likelihood. With a poorly differentiated population (S~0.2), a data set needs about five observed associations per dyad to achieve a correlation between true and estimated association indexes of r=~0.4. It requires about 10 times as much data to achieve a representation with r=~0.8. Permutation tests usually reject the null hypothesis that individuals have no preferred associates when S2H>5, where H is the mean number of observed associations per individual. Thus most situations require substantial numbers of observations of associations to give useful portrayals of social systems, and sparse association data inform only when social differentiation is high.
Keywords: association; precision; social structure; statistical power
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Robinson, I. H. (1999). The human-horse relationship: how much do we know? Equine Vet J Suppl, (28), 42–45.
Abstract: Human relationships or interactions with horses have varied throughout history depending on human needs, but it is horses' ability to carry a human individual that has had perhaps the greatest impact on their relationship with man. Despite our long association with the horse, there have been few studies on human-horse relationships. There is little historical evidence on individual relationships with horses but indications of strong human-horse relationships have been noted in mounted societies, such as North American Plains Indians. Riding a horse has traditionally been associated with power, and was reserved for the ruling elite in many areas. Demographic data suggest that human relationships with horses may have changed in recent times. Although the lack of land and the relatively high cost of horse care may reduce the possibility of ownership for many people, the availability of riding establishments and increases in leisure time mean that riding is no longer restricted to the upper classes. There is a wide range in type and intensity of potential interactions with horses, indicating that human-horse relationships are likely to vary considerably. Some people appear to sacrifice a great deal in order to own a horse. However, the motivation behind these activities and the process by which an individual assesses personal costs of ownership versus their perceived benefits remains to be studied. Future research should focus on characterising the human-horse relationship, and the degree of individual and cultural variation. A greater understanding of horse owner perceptions of 'costs' versus 'benefits' may also increase our understanding of the relationship and the economic importance of horses in society.
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