Psychological interventions used to reduce sports injuries: A systematic review of real-world effectiveness.

Objective: To systematically review studies examining the role of psychological interventions in injury prevention. The primary research question was: (1) What is the real-world effectiveness of psychological intervention in preventing sports injuries? Design: Mixed method systematic review with best evidence synthesis Data sources: CINAHL, MEDLINE, PsycARTICLES, PsycINFO, SPORTDiscus, Science Direct and PubMed Eligibility criteria for selecting studies: Randomised control trials (RCTs), non-RCTs that included a comparison group, before and after study designs and qualitative methods. Studies were required to outline specific unimodal or multimodal psychological interventions used in relation to injury prevention in the real-world setting. Outcome measure: Studies were independently appraised with the Mixed-Methods Appraisal Tool (MMAT). • Results: Thirteen papers (incorporating 14 studies) met the eligibility criteria, of which 93% (13/14) reported a decrease in injury rates (effect size range = 0.2 – 1.21). There was an overall moderate risk of bias in reporting (52%). There is a dominance of stress management-based interventions in literature due to the prominence of the Model of Stress and Athletic Injury within the area. Summary/conclusions: Psychological interventions demonstrate small (0.2) to large (1.21) effects on sports injury rates. The research area demonstrates a cumulative moderate risk in reporting bias (52%). PROSPERO registration: CRD4201603587

Which way up? Recognition of homologous DNA segments in parallel and antiparallel alignment

Homologous gene shuffling between DNA promotes genetic diversity and is an important pathway for DNA repair. For this to occur, homologous genes need to find and recognize each other. However, despite its central role in homologous recombination, the mechanism of homology recognition is still an unsolved puzzle. While specific proteins are known to play a role at later stages of recombination, an initial coarse grained recognition step has been proposed. This relies on the sequence dependence of the DNA structural parameters, such as twist and rise, mediated by intermolecular interactions, in particular electrostatic ones. In this proposed mechanism, sequences having the same base pair text, or are homologous, have lower interaction energy than those sequences with uncorrelated base pair texts; the difference termed the recognition energy. Here, we probe how the recognition energy changes when one DNA fragment slides past another, and consider, for the first time, homologous sequences in antiparallel alignment. This dependence on sliding was termed the recognition well. We find that there is recognition well for anti-parallel, homologous DNA tracts, but only a very shallow one, so that their interaction will differ little from the interaction between two nonhomologous tracts. This fact may be utilized in single molecule experiments specially targeted to test the theory. As well as this, we test previous theoretical approximations in calculating the recognition well for parallel molecules against MC simulations, and consider more rigorously the optimization of the orientations of the fragments about their long axes. The more rigorous treatment affects the recognition energy a little, when the molecules are considered rigid. However when torsional flexibility of the DNA molecules is introduced, we find excellent agreement between analytical approximation and simulation.Comment: Paper with supplemental material attached. 41 pages in all, 4 figures in main text, 3 figures in supplmental. To be submitted to Journa

Psychosocial factors associated with talent development in football: A systematic review

Objectives: To provide a critical systematic review of recent research into psychosocial factors associated with talent development in football. Design: Systematic review informed by the PRISMA guidelines. Method: Literature was sourced from Science Direct, Sport Discus, Psycharticles and Psychinfo. This was followed by a detailed screening and sifting process to identify literature. Identified literature was independently appraised by multiple reviewers using the mixed-methods Appraisal Tool (MMAT). Data was represented using concept mapping. Results: Forty-three studies met the inclusion criteria. They investigated a cumulative 14,977 participants and gleaned 48 psychosocial factors associated with talent development in football. Findings suggest that social and psychological factors are interrelated and influence adaptive developmental behaviours (e.g., adaptive lifestyle choices, practice and play behaviours). These can influence coach perceptions of players and whether they may recommend players for career progression. Independent MMAT appraisal demonstrated a moderate risk of bias. Female football players and female coaches are significantly under-represented in the literature; with white, adolescent, able-bodied, male European football players dominating the literature. Descriptive, cross-sectional, correlational and retrospective designs are most commonly adopted in the literature. Conclusions: Psychosocial factors can differentiate between performance levels of football or are positively associated with career progression to a senior elite level in football, however findings should be viewed with caution due to a moderate risk of bias in reporting. The research area would be advanced by diversification of participant groups, longitudinal, prospective designs, and by testing the predictive validity of existing grounded theories

Nucleotide Frequencies in Human Genome and Fibonacci Numbers

This work presents a mathematical model that establishes an interesting connection between nucleotide frequencies in human single-stranded DNA and the famous Fibonacci's numbers. The model relies on two assumptions. First, Chargaff's second parity rule should be valid, and, second, the nucleotide frequencies should approach limit values when the number of bases is sufficiently large. Under these two hypotheses, it is possible to predict the human nucleotide frequencies with accuracy. It is noteworthy, that the predicted values are solutions of an optimization problem, which is commonplace in many nature's phenomena.Comment: 12 pages, 2 figure