Associations between differing magnitudes of inter-limb asymmetry and linear and change of direction speed performance in male youth soccer players

Abstract Study aim: This study examines the relationship between different magnitudes of asymmetry and their effects on speed performance. Material and methods: Forty-two sub-elite male youth soccer players performed a 30-m sprint, change of direction, single leg countermovement jump and single leg hop. Subjects were divided into groups with vertical and horizontal asymmetry, and both groups were then divided into three groups according to magnitudes of inter-limb asymmetry (<5%, 5–10%, and >10%). Results: The results showed no significant correlation between different jump asymmetry magnitudes and the mentioned outcomes of speed performance (p > 0.05). In addition, larger asymmetries resulted in faster linear speed, even if small differences (g range = 0.00 to 0.57; p > 0.05). But this was not similar for change of direction speed (g range = –0.42 to 0.34; p > 0.05). Conclusions: There are inconsistent findings for the effects of inter-limb asymmetries on speed performance. The results of the present study indicate that the magnitude of asymmetry had no meaningful association with independent measures of performance in soccer players. Therefore, it seems more likely to explain the effects of individual asymmetries on performance rather than the idea that asymmetry negatively affects performance

Structural stability and energetics of single-walled carbon nanotubes under uniaxial strain

A (10x10) single-walled carbon nanotube consisting of 400 atoms with 20 layers is simulated under tensile loading using our developed O(N) parallel tight-binding molecular-dynamics algorithms. It is observed that the simulated carbon nanotube is able to carry the strain up to 122% of the relaxed tube length in elongation and up to 93% for compression. Young s modulus, tensile strength, and the Poisson ratio are calculated and the values found are 0.311 TPa, 4.92 GPa, and 0.287, respectively. The stress-strain curve is obtained. The elastic limit is observed at a strain rate of 0.09 while the breaking point is at 0.23. The frequency of vibration for the pristine (10x10) carbon nanotube in the radial direction is 4.71x10^3 GHz and it is sensitive to the strain rate.Comment: 11 pages, 8 figure

The combination of atmospheric plasma and chemical treatments for antibacterial finish on cotton

The aim of this study was to investigate the incorporation of triclosan based chemical into cyclodextrin based commercial product, bonded onto cotton fabric with and without plasma modification. The treated samples were characterized by SEM analysis. The antibacterial activities of the washed and unwashed samples were evaluated according to the AATCC Test Method 147-1998 and some physical properties were also investigated. It was observed that after the combination process of triclosan, cyclodextrin and atmospheric plasma modification, cotton fabric was able to retain its antibacterial activity up to the 5 washing cycles at 60°C

Over restrictive elimination of foods in children with foodallergy

Background. Previous studies demonstrated critical deficits in diagnosis and management of childhood foodallergy (FA), and recent developments in FA research support adopting a proactive approach in FA management.Our objective was to describe FA knowledge and management patterns of pediatricians.Method. We applied a 24-item survey to 170 general pediatricians, pediatric allergists and pediatricgastroenterologists practicing in Turkey.Results. Some IgE-mediated symptoms of FA such as cough, urticaria, wheezing and anaphylaxis were falselyrecognized as symptoms of non-IgE-mediated FA by 30%, 29%, 25% and 19% of the participants, respectively.By contrast, 50% of the participants falsely recognized bloody stool, a finding of IgE-mediated FA. Mostfrequently and least frequently used diagnostic tools were specific IgE (30.5%) and oral food challenge test(1.7%), respectively. Maternal diet restrictions and infant diet restrictions were advised by 82% and 82%,respectively. Percentages of physicians eliminating only 1 food were 21%, 19%; 2 foods were 15%, 11%; 3 foodswere 7%, 8%; 4-5 foods were 8%, 11%; 5 to 10 foods were 21%, 26%; and >10 foods were 28%, 25% from thematernal and infant diet, respectively. Cow’s milk, cheese, butter, yoghurt, baked milk products and hen’s eggwere the most commonly restricted items.Conclusion. Overall, FA knowledge of pediatricians was fair. Pediatricians utilize an overly restrictive approachwhen advising diet eliminations in FA. Recent developments favor a more proactive approach to induce immunetolerance and need to be encouraged in pediatric clinical practice. Future educational efforts should focus onemphasizing the deleterious effects of injudicious and extensive eliminations

Craniometric Data Supports Demic Diffusion Model for the Spread of Agriculture into Europe

BACKGROUND:The spread of agriculture into Europe and the ancestry of the first European farmers have been subjects of debate and controversy among geneticists, archaeologists, linguists and anthropologists. Debates have centred on the extent to which the transition was associated with the active migration of people as opposed to the diffusion of cultural practices. Recent studies have shown that patterns of human cranial shape variation can be employed as a reliable proxy for the neutral genetic relationships of human populations. METHODOLOGY/PRINCIPAL FINDINGS:Here, we employ measurements of Mesolithic (hunter-gatherers) and Neolithic (farmers) crania from Southwest Asia and Europe to test several alternative population dispersal and hunter-farmer gene-flow models. We base our alternative hypothetical models on a null evolutionary model of isolation-by-geographic and temporal distance. Partial Mantel tests were used to assess the congruence between craniometric distance and each of the geographic model matrices, while controlling for temporal distance. Our results demonstrate that the craniometric data fit a model of continuous dispersal of people (and their genes) from Southwest Asia to Europe significantly better than a null model of cultural diffusion. CONCLUSIONS/SIGNIFICANCE:Therefore, this study does not support the assertion that farming in Europe solely involved the adoption of technologies and ideas from Southwest Asia by indigenous Mesolithic hunter-gatherers. Moreover, the results highlight the utility of craniometric data for assessing patterns of past population dispersal and gene flow