An investigation into sleep patterns and the effect of time of day on performance in youth swimmers

The purpose of this study was to investigate sleep patterns in competitive youth swimmers and to establish any time-of-day effect on physiological and psychological variables linked to swimming performance. Twelve swimmers (14.8 ± 2.1 years) underwent physiological and psychological tests in morning and evening and completed sleep diaries over a 2-week period. There was a non-significant effect between morning and evening swimming performance for 800 m (p = 0.068) and 50 m (p = 0.306). Handgrip strength was significantly greater in evening (p = 0.007), back and leg strength were significantly greater in morning (p = 0.013). There was no time-of-day effect for jump height (p = 0.756). The profile of mood states indicated significantly higher anger (p = 0.012) and vigour (p = 0.000) in the morning. Swimming performance was not significantly affected by time of day; however, physiological variables showed varied results. Multiple factors could be influencing results including training time and mood state so should be monitored closely by coaches

Land based resistance training and youth swimming performance

Resistance training has been shown to have both performance-enhancing and injury reducing benefits in youth athletes. The benefits are somewhat overlooked by many swimming coaches, therefore the effects of a structured resistance training programme in highly trained youth swimmers was investigated. Nine competitive youth swimmers (age: 13 ± 1.1 years) underwent a 7 week dry-land resistance training programme. Swimming performance and other relevant physiological parameters were measured pre- and post-training. There was a small non-significant improvement in swimming performance following the 7 week training programme (100m freestyle; p > 0.05, ES = 0.26). Countermovement jump height (p < 0.05, ES = -1.26), back and leg strength (p < 0.05, ES = -1.85) and number of push ups completed in 60 s (p < 0.05, ES = -1.86) all significantly improved. Although the resistance training programme did not significantly improve swimming performance, other physiological parameters, important for success in the pool, did significantly improve. It may be that an adaptation period is needed so the swimmers can learn to efficiently apply their increased force in the water

An overview of the effect of probiotics and exercise on mood and associated health conditions

The present paper provides a review of the current knowledge relating to the health benefits of probiotics, specially focused on the effects they may have together with physical exercise on mood disorders and related chronic medical conditions. With both these conditions being a substantial contributor to the global disease burden any alternative therapy must be considered. Probiotics influence the gut microbiota through a complex network of events which can influence mechanisms leading to development of mood disorders such as depression and anxiety. Similarly, through a complex interaction between psychological and neurobiological mechanisms, exercise has been found to play a key role in mood enhancement

The influence of serial carbohydrate mouth rinsing on power output during a cycle sprint

The objective of the study was to investigate the influence of serial administration of a carbohydrate (CHO) mouth rinse on performance, metabolic and perceptual responses during a cycle sprint. Twelve physically active males (mean (± SD) age: 23.1 (3.0) years, height: 1.83 (0.07) m, body mass (BM): 86.3 (13.5) kg) completed the following mouth rinse trials in a randomized, counterbalanced, double-blind fashion; 1. 8 x 5 second rinses with a 25 ml CHO (6% w/v maltodextrin) solution, 2. 8 x 5 second rinses with a 25 ml placebo (PLA) solution. Following mouth rinse administration, participants completed a 30 second sprint on a cycle ergometer against a 0.075 g·kg-1 BM resistance. Eight participants achieved a greater peak power output (PPO) in the CHO trial, resulting in a significantly greater PPO compared with PLA (13.51 ± 2.19 vs. 13.20 ± 2. 14 W·kg-1, p < 0.05). Magnitude inference analysis reported a likely benefit (81% likelihood) of the CHO mouth rinse on PPO. In the CHO trial, mean power output (MPO) showed a trend for being greater in the first 5 seconds of the sprint and lower for the remainder of the sprint compared with the PLA trial (p > 0.05). No significant between-trials difference was reported for fatigue index, perceived exertion, arousal and nausea levels, or blood lactate and glucose concentrations. Serial administration of a CHO mouth rinse may significantly improve PPO during a cycle sprint. This improvement appears confined to the first 5 seconds of the sprint, and may come at a greater relative cost for the remainder of the sprint

Improved Constrained Global Optimization for Estimating Molecular Structure From Atomic Distances

Determination of molecular structure is commonly posed as a nonlinear optimization problem. The objective functions rely on a vast amount of structural data. As a result, the objective functions are most often nonconvex, nonsmooth, and possess many local minima. Furthermore, introduction of additional structural data into the objective function creates barriers in finding the global minimum, causes additional computational issues associated with evaluating the function, and makes physical constraint enforcement intractable. To combat the computational problems associated with standard nonlinear optimization formulations, Williams et al. (2001) proposed an atom-based optimization, referred to as GNOMAD, which complements a simple interatomic distance potential with van der Waals (VDW) constraints to provide better quality protein structures. However, the improvement in more detailed structural features such as shape and chirality requires the integration of additional constraint types. This dissertation builds on the GNOMAD algorithm in using structural data to estimate the three-dimensional structure of a protein. We develop several methods to make GNOMAD capable of effectively and efficiently handling non-distance information including torsional angles and molecular surface data. In specific, we propose a method for using distances to effectively satisfy known torsional information and show that use of this method results in a significant improvement in the quality of α-helices and β-strands within the protein. We also show that molecular surface data in combination with our improved secondary structure estimation method and long-range distance data offer increased accuracy in spatial proximity of α-helices and β-strands within the protein, and thus provide better estimates of tertiary protein structure. Lastly, we show that the enhanced GNOMAD molecular structure estimation framework is effective in predicting protein structures in the context of comparative modeling

The effect of prior upper body exercise on subsequent wingate performance

It has been reported previously that the upper body musculature is continually active during high intensity cycle ergometry. The aim of this study was to examine the effects of prior upper body exercise on subsequent Wingate (WAnT) performance. Eleven recreationally active males (20.8 ± 2.2 yrs; 77.7 ± 12.0 kg;  1.79 ± 0.04 m) completed two trials in a randomised order. In one trial participants completed 2 × 30 s WAnT tests (WAnT1 and WAnT2) with a 6 min recovery period; in the other trial, this protocol was preceded with 4 sets of biceps curls to induce localised arm fatigue. Prior upper body exercise was found to have a statistically significant detrimental effect on peak power output (PPO) during WAnT1 (P < 0.05) but no effect was observed for mean power output (MPO) (P > 0.05). Handgrip (HG) strength was also found to be significantly lower following the upper body exercise. These results demonstrate that the upper body  is meaningfully involved in the generation of leg power during intense cycling

Incorporation of Honey-Based Phenolic Acids Into Shape Memory Polymer Foams for Use as Antimicrobial Hemostat

Polyurethane shape memory polymer (SMP) foams are ultra-low density, “smart” materials that transition between a primary and secondary shape when exposed to a thermal stimulus. This material has the potential to be used in a new application as a hemostatic wound dressing. Honey-based phenolic acids are a class of naturally occurring antimicrobial substances produced by bees to protect their hives from harmful microbes in the environment. To tune the properties of SMP foams to best serve the proposed application, these honey-based phenolic acids will be incorporated into the polymer backbone to impart antimicrobial properties to the foams. An esterification reaction involving a phenolic acid and N,N,N,N’-tetrakis(2-hydroxypropyl) ethylene diamine (HPED) is carried out to produce a modified HPED molecule where one of the alcohol groups is replaced by the phenolic acid. SMP foams are then synthesized using hexamethylene diisocyanate (HDI), HPED, and varied amounts of triethanolamine (TEA) and the modified HPED-phenolic acid monomer. The resultant foams are characterized to determine their density, pore size, glass transition temperature (Tg), rate of thermal actuation, and antimicrobial properties

Can Emergency Physicians Perform Carotid Artery Point-of-Care Ultrasound to Detect Stenosis in Patients with TIA and Stroke? A Pilot Study

Introduction: Patients with severe, symptomatic carotid stenosis can have their subsequent stroke risk reduced by surgical intervention if performed soon after a transient ischemic attack (TIA) or stroke. Patients presenting to an emergency department (ED) without computed tomography angiography (CTA) with TIA/stroke, may require transfer to another hospital for imaging to rule out carotid artery stenosis. The objective of this study was to determine the test characteristics of carotid artery point-of-care ultrasound (POCUS) in detecting greater than 50% stenosis in patients presenting with TIA/stroke.Methods: We conducted a prospective cohort study on a convenience sample of adult patients presenting to a comprehensive stroke centre with TIA or stroke between June–October 2017. Carotid POCUS was performed. Primary outcome measure, stenosis ≥ 50%, was determined by the final radiology report of CTA. A blinded POCUS expert separately reviewed the archived carotid POCUS scans. We calculated sensitivity and specificity for stenosis ≥ 50%.Results: We conducted POCUS on 75 patients, of which 70 were included in our analyses. Of those 70, 14.3% were diagnosed with greater than 50% stenosis. Carotid POCUS performed as follows: sensitivity 70.0% (95% confidence interval [CI], 34.8%-93.3%); specificity 86.7% (95% CI, 75.4%-94.1%); positive likelihood ratio (LR +) 5.3 (95% CI, 1.2-9.3); negative likelihood ratio (LR -) 0.4 (95% CI, 0.0-0.7). The inter-rater reliability between POCUS performer interpretation and expert interpretation had moderate agreement (k = 0.68). Scans took a mean 6.2 ± 2.2 minutes to complete.Conclusion: Carotid POCUS has low to moderate association with CTA for detection of carotid artery stenosis ≥ 50%. Further research and investigation is needed prior to widespread use of carotid POCUS in patients with acute cerebral ischemia. Additionally, external validity is likely affected by availability of training, maintenance of competency, and experience in more rural centres

Attitudes Towards Vaccination Among Medical Students: A Two-Site Study

Introduction: Mandatory immunization for school age children in the 20th Century led to a substantial decline in infectious disease. All US states allow medical exemptions from immunizations with 49 permitting additional religious exemptions and 19 permitting additional philosophical exemptions. Vaccine exemptions have lead to an increase in the incidence of disease outbreaks. Healthcare providers play a critical role in educating parents about the benefits and risks of immunizations. This project compares student attitudes and knowledge regarding vaccination at medical schools in two distinct states: one with no additional exemptions (West Virginia) and one with both additional exemptions (Vermont).https://scholarworks.uvm.edu/comphp_gallery/1218/thumbnail.jp

Weekly vitamin D₃ supplementation improves aerobic performance in combat sport athletes

Vitamin D3 supplementation can affect the strength and power of an athlete, however the effect on endurance performance remains unclear. Twenty-seven recreational male combat athletes with at least 12 months experience within combat sports were recruited (age: 24 ± 4 years, stature: 176 ± 6 cm, weight: 77 ± 14 kg). Participants completed baseline testing for blood haemoglobin and haematocrit, upper and lower body VO2peak and upper and lower body Wingate. Following testing participants were stratified to 50000IU (D1), 80000IU (D2) or 110000IU (D3) of vitamin D3 per week. They then completed a 6-week placebo period followed by a 6-week supplementation period. Retesting was carried out after the placebo and supplementation period. There was a significant effect for time for haemoglobin and haematocrit, upper and lower body VO2peak and upper body Wingate power (p<0.01) but no effect for dose of vitamin D given. Performance data was normalised to vitamin D intake and there was a moderate effect size between D1 and D2 for lower body VO2peak (d=0.6), upper body VO2peak (d=0.13) and upper body average power (d=0.75), with a large effect size between D1 and D2 for haemoglobin (d=1.19), haematocrit (d=0.93) and upper body peak power (d=0.95). There was a large effect size for D1 compared to D3 for all variables (d>0.8). Therefore, there is no additional benefit to increasing dose above 500000IU vitamin D per week. Given the endurance adaptations from vitamin D supplementation and the importance of endurance for combat performance, recreational combat athletes should supplement at 50000IU per week for six weeks