On-time maturation in female adolescent ballet dancers: Learning from lived experiences

This is the final version. Available on open access from SAGE Publications via the DOI in this recordThis study employed semi-structured interviews and Interpretative Phenomenological Analysis to explore experiences of on-time maturation in nine adolescent ballet dancers from across three vocational ballet schools in the United Kingdom. Two themes were identified as central to their experiences: ‘A right and a wrong way to grow’, and fitting in and moving forward. Instead of perceiving themselves as ‘average’ and experiencing a relatively easy pubertal transition, on-time dancers described unique challenges associated with a fluctuation between fitting in and not fitting in within their social context. The implications of on-time maturation in this context are complex and do not appear to follow the same trajectory as early maturing ballet dancers nor on-time non-dancers

Of grit and grace: negotiating puberty, surviving, and succeeding in professional ballet

This is the author accepted manuscript. The final version is available from Human Kinetics via the DOI in this recordExperiences of puberty and how individuals adapt to puberty may be integral to success in ballet; however, there is a paucity of current research in this area. This study explores the lived experiences of nine professional ballet dancers to capture the journey of negotiating puberty in a ballet context. An interpretative phenomenological analysis approach was employed with semistructured interviews utilized to gather rich, descriptive accounts from nine professional ballet dancers from the United Kingdom and United States. Lived experiences were characterized by conflict and struggle, coming to terms with physical changes and possessing grit and grace in order to successfully negotiate puberty, and to succeed and survive in professional ballet. Accepting physical and esthetic strengths and weaknesses and learning how to adapt or how to compensate for weaknesses was described as pivotal. Factors such as social support, the timing and extent of pubertal changes, dance teacher behaviors, and the ballet training context influenced the extent to which dancers experienced conflict and struggle and how easily they were able to come to terms with their adult physique. Further research is needed to explore the implications of maturing and developing within the context of ballet training and to develop strategies to better facilitate healthy development in ballet

Beyond the coaches eye: Understanding the ‘how’ and ‘why’ of maturity selection biases in male academy soccer

This study explored academy football coaches’ perceptions and experiences of managing individual differences in the maturity timing of male adolescent football players in an English Premier League academy. Using a longitudinal mixed method design, 98 under 12–16 players were assessed for maturity status, growth velocities, and match performance grade. Interviews with nine respective coaches were conducted in parallel. The qualitative and quantitative data were combined to generate a contextualised richer understanding and four archetypal case studies. Findings showed coaches perceive various advantages and disadvantages to players maturing either ahead or in the delay of their peers and had different expectations of performance based upon a players maturity status; biological maturity status and timing had large implications for selection and release decisions. This study highlights the challenges of developing, managing and selecting adolescent players in elite male youth football. Biological maturation confounds talent identification and development, and academy environments need to monitor maturity status and educate coaches and selectors on the complexities and intricacies of individual differences in maturity timing

The H in WASH: a reflection on the contribution, style and legacy of professor Val Curtis

In this paper we reflect on the contribution, style and legacy of Professor Val Curtis, an important, and sometimes controversial, figure in the water, sanitation and hygiene (WASH) sector who sadly passed away on October 19, 2020. Across numerous scientific articles, and several books, and operational programmes, she established herself as a world-renowned scientific expert in the field of hygiene and behaviour change, as well as a major thought-leader in the WASH sector. We identify four major scientific contributions which she made over three decades of research that spanned multiple fields, including engineering, epidemiology, and psychology. Beyond her research, she tirelessly championed hygiene as a public health priority, using her talents as a communicator to secure concrete changes in relevant policy and practice. We are confident that her example, as both a public health researcher, and as a hygiene champion, will inspire future generations of WASH researchers and practitioners to be bold and ambitious

Predicting the timing of the peak of the pubertal growth spurt in elite youth soccer players: evaluation of methods.

Background: Three commonly used non-invasive protocols are implemented to estimate the timing at which PHV most likely occurs. Accurate estimation of circumpubertal years can aid in managing training load of adolescent athletes.Aim: Three protocols were compared against observed age at PHV: an estimate of 13.8 ± 1.0 years - generic age at PHV (from longitudinal measures); an estimate based on the maturity offset equation, predicted age at PHV ±1.0 year; a window of PHV based on 85 - 96% of predicted adult height at time of observation.Subjects and methods: A final sample of 23 (from 28) adolescent participants who were selected from the academy of an English Premier League club. Anthropometric measures were collected across five playing seasons; age at PHV was estimated with Super-Imposition by Translation and Rotation (SITAR). The three protocols were compared based on measures at 13.0 years.Results and Conclusions: An age window based on predicted maturity offset did not improve estimation of PHV compared to generic age method; however, the percentage of predicted adult height window showed improvement in performance shown by the following results. Predicted age at PHV correctly assigned 15 participants (65%) as experiencing PHV, while the percentage height correctly assigned 17 participants (74%). Generic age and predicted age at PHV correctly predicted observed age at PHV for 14 participants (61%), percentage of adult height window correctly predicted 22 participants (96%)

The fallacy of placing confidence in confidence intervals

Interval estimates – estimates of parameters that include an allowance for sampling uncertainty – have long been touted as a key component of statistical analyses. There are several kinds of interval estimates, but the most popular are confidence intervals (CIs): intervals that contain the true parameter value in some known proportion of repeated samples, on average. The width of confidence intervals is thought to index the precision of an estimate; CIs are thought to be a guide to which parameter values are plausible or reasonable; and the confidence coefficient of the interval (e.g., 95 %) is thought to index the plausibility that the true parameter is included in the interval. We show in a number of examples that CIs do not necessarily have any of these properties, and can lead to unjustified or arbitrary inferences. For this reason, we caution against relying upon confidence interval theory to justify interval estimates, and suggest that other theories of interval estimation should be used instead

Spatial Stereoresolution for Depth Corrugations May Be Set in Primary Visual Cortex

Stereo “3D” depth perception requires the visual system to extract binocular disparities between the two eyes' images. Several current models of this process, based on the known physiology of primary visual cortex (V1), do this by computing a piecewise-frontoparallel local cross-correlation between the left and right eye's images. The size of the “window” within which detectors examine the local cross-correlation corresponds to the receptive field size of V1 neurons. This basic model has successfully captured many aspects of human depth perception. In particular, it accounts for the low human stereoresolution for sinusoidal depth corrugations, suggesting that the limit on stereoresolution may be set in primary visual cortex. An important feature of the model, reflecting a key property of V1 neurons, is that the initial disparity encoding is performed by detectors tuned to locally uniform patches of disparity. Such detectors respond better to square-wave depth corrugations, since these are locally flat, than to sinusoidal corrugations which are slanted almost everywhere. Consequently, for any given window size, current models predict better performance for square-wave disparity corrugations than for sine-wave corrugations at high amplitudes. We have recently shown that this prediction is not borne out: humans perform no better with square-wave than with sine-wave corrugations, even at high amplitudes. The failure of this prediction raised the question of whether stereoresolution may actually be set at later stages of cortical processing, perhaps involving neurons tuned to disparity slant or curvature. Here we extend the local cross-correlation model to include existing physiological and psychophysical evidence indicating that larger disparities are detected by neurons with larger receptive fields (a size/disparity correlation). We show that this simple modification succeeds in reconciling the model with human results, confirming that stereoresolution for disparity gratings may indeed be limited by the size of receptive fields in primary visual cortex

Modelling human visual navigation using multi-view scene reconstruction

It is often assumed that humans generate a 3D reconstruction of the environment, either in egocentric or world-based coordinates, but the steps involved are unknown. Here, we propose two reconstruction-based models, evaluated using data from two tasks in immersive virtual reality. We model the observer’s prediction of landmark location based on standard photogrammetric methods and then combine location predictions to compute likelihood maps of navigation behaviour. In one model, each scene point is treated independently in the reconstruction; in the other, the pertinent variable is the spatial relationship between pairs of points. Participants viewed a simple environment from one location, were transported (virtually) to another part of the scene and were asked to navigate back. Error distributions varied substantially with changes in scene layout; we compared these directly with the likelihood maps to quantify the success of the models. We also measured error distributions when participants manipulated the location of a landmark to match the preceding interval, providing a direct test of the landmark-location stage of the navigation models. Models such as this, which start with scenes and end with a probabilistic prediction of behaviour, are likely to be increasingly useful for understanding 3D vision