Conceptualizing minimalist footwear: an objective definition     

Devon R. Coetzee  Yumna Albertus  Nicholas Tam  Ross Tucker 《Journal of sports sciences》2018,36(8):949-954

Running has been plagued with an alarmingly high incidence of injury, which has resulted in the exploration of interventions aimed at reducing the risk of running-related injury. One such intervention is the introduction of footwear that mimics barefoot running. These have been termed minimalist shoes.

Minimalist footwear aims to reduce the risk of injury by promoting adaptations in running biomechanics that have been linked to a reduction in both impact and joint forces. However, some studies have found that minimalist footwear may be beneficial to the runner as they promote favourable biomechanical adaptations, whilst other studies have found the opposite to be true.

Reasons for these conflicting results could be attributed to the lack of a definition for minimalist footwear. The aim of this review article is to provide a structural definition for minimalist footwear based on studies that have examined the influence of footwear on biomechanical variables during running.

Based on current literature, we define minimalist footwear as a shoe with a highly flexible sole and upper that weighs 200g or less, has a heel stack height of 20mm or less and a heel-toe differential of 7mm or less.  相似文献   

Effect of wetted surface area on friction,pressure, wave and total drag of a kayak     

Beatriz B. Gomes  Leandro Machado  Nuno V. Ramos  Filipe A. V. Conceição  Ross H. Sanders  Mário A. P. Vaz 《Sports biomechanics / International Society of Biomechanics in Sports》2018,17(4):453-461

Using theoretical principles, the components of drag (friction D _F, pressure D _PR and wave D _W) of a single-seat kayak were analysed. The purpose was to examine the effect of changes in wetted surface area due to changes in kayaker’s weight and the relative contribution of D _F, D _PR and D _W to the total passive drag as function of velocity. The total passive drag values were based on experimental data collected in a single-seat kayak. Three different kayaker simulated weights were tested – 65, 75 and 85 kg. D _F was the drag component that contributed the greatest percentage (between 60 and 68% at 5.56 m/s the top velocity tested) to the total passive drag for all the velocities tested and simulated weights. D _W was the most affected by the increase in kayaker’s simulated weight, mainly when comparing 65/75 to 85 kg. Results support the importance of a kayak design selection that minimises the kayak’s drag for the individual weight of the kayaker. Also, the results suggest that the path for better hydrodynamic kayak performance should seek changes that can reduce D _F, D _PR and D _W with D _F offering the most potential to reduce passive drag.  相似文献   

Forgeries of Fossils in “Amber”: History,Identification and Case Studies     

David A. Grimaldi  Alexander Shedrinsky  Andrew Ross  Norbert S. Baer 《Curator: The Museum Journal》1994,37(4):251-274

The appeal of ancient fossilized tree resin, or amber, has made pieces with animal and plant inclusions particularly prized. Unfortunately, amber forgeries are more convincingly and routinely made than most other kinds of fossils, by embedding organisms in natural resins (e.g., copal) or synthetic resins (especially polyester) or by filling a carved niche in a natural piece of amber with resin and a modern inclusion. The confusion of organisms in copal (forged and natural) for ones in amber has a long history. Reviewed here are simple tests for discerning forgeries and natural inclusions in both substances. We discuss an old but sophisticated technique for crafting amber forgeries from authentic amber and present several new examples from old collections in two large museum collections. Also discussed is the widespread use of polyester resin forgeries in the Dominican Republic and Mexico.  相似文献   

Sales Teams or Salespersons: Performance Implications for Embracing Individualistic and Collectivistic Cultural Values in a Global Marketplace     

Lawrence E. Ross  Katie P. Desiderio  Michael Knudstrup  Michael G. Frino 《Performance Improvement Quarterly》2014,26(4):53-73

Identifying antecedents of salesperson performance is a long‐standing objective in the sales management research field. The purpose of this article is to outline how the practical understanding of, and the willingness to embrace, sales employees' cultural value‐systems adds value while considering performance drivers, individualistic versus collectivistic values, and performance outcomes. The cultural dimensions under consideration, individualism and collectivism, cannot be approached as a dichotomy. As is the case for all cultural dimensions, they represent a continuum and not absolutes. In this study, the work preferences and predispositions of participants were compared using an international data set. Respondents were culturally classified based on research (i.e., Americans and Australians as individualists and Japanese and South Koreans as collectivists). Specifically, it was found that individualists were less attached to their current work situation; collectivists indicated less work/family conflict; and individualists valued independent work more while collectivists valued deciding work time. This is important because of the need to understand how to effectively connect with the values of people to encourage positive performance outcomes. The reality is that value holds differing degrees of emphasis; the performance formula is the theoretical framework to guide this research. The implications of the results for sales management professionals are discussed.  相似文献   

The conspiracy: To have pfun     

Ken Ross 《Performance Improvement》1991,30(2):6-8

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