Confirming the Value of Adolescent Swimming Performance Models

This is the author accepted manuscript. The final version is available from Human Kinetics via the DOI in this record.PURPOSE: To evaluate the efficacy of existing performance models to assess the progression of male and female adolescent swimmers through a quantitative and qualitative mixed-methods approach. METHODS: Fourteen published models were tested using retrospective data from an independent sample of Dutch junior national-level swimmers from when they were between 12 and 18 years of age (n=13). The degree of association by Pearson's correlations were compared between the calculated differences from the models and quadratic functions derived from the Dutch junior national qualifying times. Swimmers were grouped based on their differences from the models and compared with their swimming histories that were extracted from questionnaires and follow-up interviews. RESULTS: Correlations of the deviations from both the models and quadratic functions derived from the Dutch qualifying times were all significant except for the 100 m breaststroke and butterfly and the 200 m freestyle female events (p<0.05). Additionally, the 100 m freestyle and backstroke for males and 200 m freestyle male and female events were almost directly proportional. In general deviations from the models were accounted for by the swimmers' training histories. Higher levels of retrospective motivation appeared to be synonymous with higher-level career performance. CONCLUSIONS: This mixed-methods approach helped to confirm the validity of the models that were found to be applicable to adolescent swimmers at all levels, allowing coaches to track performance and set goals. The value of the models in being able to account for the expected performance gains during adolescence allows for peripheral factors that could affect performance to be quantified

'Choosing shoes': a preliminary study into the challenges facing clinicians in assessing footwear for rheumatoid patients

Background: Footwear has been accepted as a therapeutic intervention for the foot affected by rheumatoid arthritis (RA). Evidence relating to the objective assessment of footwear in patients with RA is limited. The aims of this study were to identify current footwear styles, footwear characteristics, and factors that influence footwear choice experienced by patients with RA. Methods: Eighty patients with RA were recruited from rheumatology clinics during the summer months. Clinical characteristics, global function, and foot impairment and disability measures were recorded. Current footwear, footwear characteristics and the factors associated with choice of footwear were identified. Suitability of footwear was recorded using pre-determined criteria for assessing footwear type, based on a previous study of foot pain. Results: The patients had longstanding RA with moderate-to severe disability and impairment. The foot and ankle assessment demonstrated a low-arch profile with both forefoot and rearfoot structural deformities. Over 50% of shoes worn by patients were opentype footwear. More than 70% of patients’ footwear was defined as being poor. Poor footwear characteristics such as heel rigidity and sole hardness were observed. Patients reported comfort (17%) and fit (14%) as important factors in choosing their own footwear. Only five percent (5%) of patients wore therapeutic footwear. Conclusions: The majority of patients with RA wear footwear that has been previously described as poor. Future work needs to aim to define and justify the specific features of footwear that may be of benefit to foot health for people with RA

Modelling the Progression of Male Swimmers’ Performances through Adolescence

Insufficient data on adolescent athletes is contributing to the challenges facing youth athletic development and accurate talent identification. The purpose of this study was to model the progression of male sub-elite swimmers’ performances during adolescence. The performances of 446 males (12–19 year olds) competing in seven individual events (50, 100, 200 m freestyle, 100 m backstroke, breaststroke, butterfly, 200 m individual medley) over an eight-year period at an annual international schools swimming championship, run under FINA regulations were collected. Quadratic functions for each event were determined using mixed linear models. Thresholds of peak performance were achieved between the ages of 18.5 ± 0.1 (50 m freestyle and 200 m individual medley) and 19.8 ± 0.1 (100 m butterfly) years. The slowest rate of improvement was observed in the 200 m individual medley (20.7%) and the highest in the 100 m butterfly (26.2%). Butterfly does however appear to be one of the last strokes in which males specialise. The models may be useful as talent identification tools, as they predict the age at which an average sub-elite swimmer could potentially peak. The expected rate of improvement could serve as a tool in which to monitor and evaluate benchmarks

RCD snubber revisited

Published versio

The effect of additives on the hydration of CaSO4·0.5H2O: A synchrotron X-ray diffraction study

To modulate the rate of hydration of calcium sulfate hemihydrate (HH) to calcium sulfate dihydrate for industrial applications, additives (both accelerants and retardants) are added to the HH. Here we explore in detail the kinetics and mechanism of HH hydration in the presence of the accelerators K2SO4 or ZnSO4, and also when a retardant (citric acid or tartaric acid) is added. Retardants tend to lower the maximum temperature of the reaction and increase the time needed to reach 50% hydration, yet the total conversion percentage is much higher for citric acid/tartaric acid then when an accelerant is added. The reaction process is found to involve heterogenous nucleation regardless of the nature of the additive. More soluble accelerants act mainly though increasing the rate of crystal growth, while less soluble species have a more significant effect on the rate of nucleation

Online misinformation about climate change

This is the final version. Available from the publisher via the DOI in this record.Policymakers, scholars, and practitioners have all called attention to the issue of misinformation in the climate change debate. But what is climate change misinformation, who is involved, how does it spread, why does it matter, and what can be done about it? Climate change misinformation is closely linked to climate change skepticism, denial, and contrarianism. A network of actors are involved in financing, producing, and amplifying misinformation. Once in the public domain, characteristics of online social networks, such as homophily, polarization, and echo chambers—characteristics also found in climate change debate—provide fertile ground for misinformation to spread. Underlying belief systems and social norms, as well as psychological heuristics such as confirmation bias, are further factors which contribute to the spread of misinformation. A variety of ways to understand and address misinformation, from a diversity of disciplines, are discussed. These include educational, technological, regulatory, and psychological-based approaches. No single approach addresses all concerns about misinformation, and all have limitations, necessitating an interdisciplinary approach to tackle this multifaceted issue. Key research gaps include understanding the diffusion of climate change misinformation on social media, and examining whether misinformation extends to climate alarmism, as well as climate denial. This article explores the concepts of misinformation and disinformation and defines disinformation to be a subset of misinformation. A diversity of disciplinary and interdisciplinary literature is reviewed to fully interrogate the concept of misinformation—and within this, disinformation—particularly as it pertains to climate change. This article is categorized under:. Perceptions, Behavior, and Communication of Climate Change > Communication.Economic and Social Research Council (ESRC

Environmental selection and resource allocation determine spatial patterns in picophytoplankton cell size

Here we describe a new trait-based model for cellular resource allocation that we use to investigate the relative importance of different drivers for small cell size in phytoplankton. Using the model, we show that increased investment in nonscalable structural components with decreasing cell size leads to a trade-off between cell size, nutrient and light affinity, and growth rate. Within the most extreme nutrient-limited, stratified environments, resource competition theory then predicts a trend toward larger minimum cell size with increasing depth. We demonstrate that this explains observed trends using a marine ecosystem model that represents selection and adaptation of a diverse community defined by traits for cell size and subcellular resource allocation. This framework for linking cellular physiology to environmental selection can be used to investigate the adaptive response of the marine microbial community to environmental conditions and the adaptive value of variations in cellular physiology