INFLUENCE OF NATURAL GRASS AND ARTIFICIAL TURF SURFACES ON ATHLETE PERFORMANCE AND PERCEIVED PERFORMANCE SATISFACTION

Hannah Reck1, Brandi Decoux1, Samantha Carson1, Daniel B. Hollander1, Megan Gordon1, Bovorn Sirikul1, Christopher Wilburn2, Wendi Weimar2. 1Southeastern Louisiana University, Hammond, LA. 2Auburn University, Auburn, AL. BACKGROUND: Examination of athlete performance and perceptions across different playing surfaces has provided useful information to better understand athlete preferences, tactical alterations, and focus areas for industry/material science developers. However, much of the previous research on natural grass (NG) and artificial turf (AT) surfaces has been limited in scope to comparisons of only performance measures or only perceptual ratings. Additionally, fewer studies have assessed both performance and perception across multiple AT surfaces and NG within the same project. Thus, the purpose of this study was to investigate the influence of NG and different AT playing surfaces on athlete performance and perceived performance satisfaction. METHODS: Seventeen male participants (age: 23.1 ± 2.9 years; height: 1.81 ± 0.06 m; mass: 77.8 ± 9.9 kg) completed three 20-yard sprint trials and three change of direction (CoD) trials (i.e., 5-10-5 agility) on four playing surfaces-one NG surface and three AT surfaces with varying structural components. After completion of all performance tests, each participant then responded to a visual analogue scale (VAS) questionnaire for each surface regarding their satisfaction with the surface’s grip/traction and softness/compliance as well as their ability to change direction and accelerate. Friedman tests were conducted to compare sprint time, CoD time, CoD deficit, and the VAS scores across all surfaces. RESULTS: There were statistically significant differences detected for CoD deficit (χ2(3)= 9.071, p= 0.028), acceleration VAS score (χ2(3)= 10.089, p= 0.018), and softness/compliance VAS score (χ2(3)= 10.804, p= 0.013). Post hoc Wilcoxon signed-rank tests with a Bonferroni correction (a=.0125) revealed that CoD deficit on the third AT surface was larger than on NG (p= .008), the third AT was ranked higher for acceleration VAS score than the second AT (p=.003), and the third AT was ranked lower than NG for softness/compliance VAS score (p=.002). CONCLUSION: Interestingly, the participants in this study perceived the third AT to be a harder surface that they could accelerate better on, and yet CoD deficit, a measure that is improved by enhanced acceleration ability, was compromised on this surface compared to NG. These findings suggest that perceptions of the performance-related characteristics of AT and actual performance are not always congruent. KEYWORDS: Perception, Performance, Artificial turf, Natural Gras

Olfactory effects of a hypervariable multicomponent pheromone in the red-legged salamander, Plethodon shermani

Chemical communication via chemosensory signaling is an essential process for promoting and modifying reproductive behavior in many species. During courtship in plethodontid salamanders, males deliver a mixture of non-volatile proteinaceous pheromones that activate chemosensory neurons in the vomeronasal epithelium (VNE) and increase female receptivity. One component of this mixture, Plethodontid Modulating Factor (PMF), is a hypervariable pheromone expressed as more than 30 unique isoforms that differ between individual males-likely driven by co-evolution with female receptors to promote gene duplication and positive selection of the PMF gene complex. Courtship trials with females receiving different PMF isoform mixtures had variable effects on female mating receptivity, with only the most complex mixtures increasing receptivity, such that we believe that sufficient isoform diversity allows males to improve their reproductive success with any female in the mating population. The aim of this study was to test the effects of isoform variability on VNE neuron activation using the agmatine uptake assay. All isoform mixtures activated a similar number of neurons (>200% over background) except for a single purified PMF isoform (+17%). These data further support the hypothesis that PMF isoforms act synergistically in order to regulate female receptivity, and different putative mechanisms are discussed