The impact of information quantity and strength of relationship between training set and validation set on accuracy of genomic estimated breeding values

Recent advances in genomic selection are a revolution in animal breeding. A genome consisting 10 chromosomes each with 100 cM in length with 100 equally spaced markers (1 cM) were simulated. After 50 generations of random mating in a finite population (Ne = 100) in order to create sufficient linkage disequilibrium, population was expanded to two different population sizes of 500 and 1000. This structure was conserved until generation 59. Only females of generations 51 to 58 had phenotypicrecords and were included in the training set. The generation 59 was assumed as juveniles without any phenotypic records (validation set). Two measures of heritability (h2 = 0.1 and h2 = 0.5) were considered.Each simulation was replicated 10 times and results were averaged across replications. The results showed that using individuals of more recent generations in training set led to higher accuracy of genomic estimated breeding values (GEBVs) than individuals from more distant generations. However, increase in the amount of phenotypic records in training set even from individuals of older generations will increase accuracy of GEBVs. Number of phenotypic records in training set was shown to haveimportant role in accuracy of GEBVs especially for low heritability traits

The effect of a semi-rigid thoracolumbosacral orthosis (TLSO) on foot pressure in elderly subjects presenting with spinal hyperkyphosis

Purpose: The ageing process can be accompanied by a degeneration of the spine and increase the risk of thoracic hyperkyphosis (excessive spinal forward curvature) amongst elderly people. This condition can in turn impair mobility, reduce balance, and increase the risk of falling and mortality in affected individuals. The use of corrective orthotic bracing has been shown to improve spinal posture, and increase stability and balance amongst the elderly. However, there is little evidence that evaluates the use of corrective braces on foot pressure changes in these subjects. Methods: In this study, we evaluated the use of a thoracolumbosacral orthosis (TLSO) on 19 subjects over 60 years old who presented with hyperkyphosis. We measured foot pressure using the Pedar-X system before (without brace) and after (with brace) immediate using a TLSO in both static (quite standing) and dynamic (walking on a 5 meters freeway) scenarios. Results: The results demonstrated that using a TLSO immediately decreases forefoot pressures in stasis, and around the first metatarsal, as well as pressures relating to the second to fifth metatarsals under dynamic conditions. Hindfoot pressures were increased, but not significantly. Conclusion: This study showed that using a TLSO can be beneficial for elderly people with hyperkyphosis. Implications for rehabilitation The ageing process can be accompanied by a degeneration of the spine and increase the risk of thoracic hyperkyphosis. The use of corrective orthotic bracing has been shown to improve spinal posture, and increase stability and balance amongst the elderly. Using a TLSO decreases forefoot pressures in stasis, and around the first metatarsal, as well as pressures relating to the second to fifth metatarsals under dynamic conditions