26 research outputs found
Laboratory-based ergometry for swimmers: a narrative review
INTRODUCTION:
First widely available dry-land training machines for swimmers were introduced about 40 years ago. They were designed so that swimmers could perform resistance exercise whilst more-closely replicating the movements of swimming, than when using other gymnasium-based resistance training machines. This narrative review categorises and summarises what has been shown by the studies that have utilised laboratory-based ergometry for swimmers.
EVIDENCE ACQUISITION:
A systematic search was conducted in PubMed, Web of Science, ScienceDirect and Scopus (1970-2018) and relevant publications were included. Publications were grouped into 4 main areas of research: (i) physiological responses to exercise, (ii) functional evaluation of swimmers, (iii) monitoring of training, and (iv) muscular work output of swimmers.
EVIDENCE SYNTHESIS:
Significant differences were showed between swim bench exercise and real swimming, especially in regard to the muscles involved. The difficulties of accurate reproduction of the movements and coordinated dynamic actions of swimming have not been overcome. Nevertheless, the literature shows that the use of these devices has provided a valuablecontribution to swimming physiology, while overcoming difficulties presented by attempting to make physiological measurements in the water.
CONCLUSIONS:
In spite of its limitations, laboratory-based ergometry has allowed a valuable contribution to the understanding of the physiology, effects of training and efficiency of swimming
Exercise, plasma catecholamine concentrations and decision-making performance of soccer players on a soccer-speciWc test
The main aim of this study was to compare the decision-making performance of college soccer players on a
soccer-speciWc, tachistoscopically presented test, at rest and while exercising at their adrenaline threshold and at
their maximum power output. These were determined following an incremental test to exhaustion on a cycle
ergometer. After the initial maximum power test, participants (n = 9) were allowed 10 habituation trials on the
soccer decision-making test. Participants’ decision-making performance was tested at rest, while cycling at a
power output that had previously been determined to elicit their adrenaline threshold and while cycling at
maximum power output. Accuracy and speed of decision were the dependent variables. A one-way repeatedmeasures
analysis of variance showed no signiWcant eV ect of exercise on accuracy, and showed speed of decision
to be signiWcantly aV ected by exercise. Tukey post-hoc tests showed that speed of decision at rest was signiWcantly
slower than in the other two conditions, which did not diV er signiWcantly from one another. Based on allocatable
resources theories of arousal and performance, we conclude that the adrenaline threshold may be indicative of
increases in the resources available to the individual. Furthermore, we considered that exercise at maximum
power output may only induce a moderate rather than a high level of arousal
Sustainability strategies by companies in the global coffee sector
The coffee sector is facing several sustainability challenges. We ask whether addressing these is transforming the entire coffee sector or rather leading to market differentiation. Drawing on stakeholder theory and global value chain analysis, we analyse how the coffee sector approaches sustainability by examining the sustainability efforts of a random sample of 513 companies. We also identify the factors shaping the adoption of sustainability strategies. A third of companies report no commitment to sustainability, whereas another third report vague commitment. The final third of companies report tangible commitments to sustainability. Company characteristics and stakeholders affect the scope and type of sustainability strategy chosen. Large, risk-aware companies tend to conduct ‘hands-on’ governance, adopting internal sustainability practices along their value chain. Small, consumerfacing companies and producers rely on ‘hands-off’ governance, adopting external voluntary sustainability standards. Several sustainability issues remain underaddressed by most companies, including climate change and deforestation. We found indications of potential greenwashing by some companies. Addressing sustainability is not yet fully mainstreamed in the sector, though ambitious commitments by sustainability leaders and large actors signal increasing importance of sustainability as part of corporate social responsibility efforts. We observe market differentiation through sustainability with progressive companies adopting sustainability strategies that align with their stakeholders, depending on value chain characteristics. Our results indicate a notable reliance on internal sustainability practices. There is a need for common coffee sustainability indicators relevant for all actors along the value chain, which are consistent with the Sustainable Development Goals, and a transparent, mandatory reporting framework
Leaching characteristics of homologues of benzalkonium chloride from wood treated with ammoniacal copper quaternary wood preservative
Violent conflict and social transformation: An institutionalist approach to the role of informal economic networks
Cet article cherche à contribuer à la discussion à propos du rôle des réseaux économiques informels lors de conflits violents. Il soutient que les transformations sociales qui découlent d'un conflit peuvent être soit productives ou destructives, selon la nature des institutions imbriquées au sein des réseaux sociaux. Il souligne en particulier la manière dont la relation historique des réseaux informels avec l'Etat façonne le contenu institutionnel de ces réseaux informels. Deux études de cas contrastées sont présentéés afin d'illustrer ceci. En Somalie, les institutions traditionelles de confiance et de réciprocité furent préservées lors du conflit, et ont contribué à la coordination économique ainsi qu'à la médiation du conflit. Au Sierra Leone, l'intrusion de réseaux patrimoniaux dans la vie communautaire traditionelle suite au conflit a contribué au développement de réseaux de jeunes ayant un comportement anti-social et opportuniste, ce qui causa un effondrement social.European Journal of Development Research (2009) 21, 81–94. doi:10.1057/ejdr.2008.8