Talent development in female soccer: Developmental activities of professional players in England.

The activities soccer players engage in during their formative years are thought to significantly contribute to the acquisition of expert performance. Whilst this area has seen great interest in male players, there has been little research in females. The study examined developmental activities engaged in by professional female soccer players in England. 56 female soccer players that had either progressed to professional status in adulthood (professional), or did not (ex-academy), completed the Participant History Questionnaire. Professional players started engaging in soccer at an earlier age than their ex-academy counterparts, resulting in greater engagement in practice and play during childhood. During adolescence, professional players engaged in higher amounts of practice than ex-academy players. Engagement in competition and practice was rated as high in physical and cognitive effort by all, yet ex-academy players reported higher levels of physical effort during early adolescence, and cognitive effort during late adolescence. Findings provide an illustration of the talent pathways of professional female soccer players in England and may inform future talent development systems. Large interindividual variation in soccer-specific and other-sport activity data highlight the importance of further understanding the environments of individual soccer nations and their potential impact on the talent identification and development processes.

Evaluation of multi-directional speed qualities throughout adolescence in youth soccer: The non-linear nature of transfer.

Training and assessment of agility is often prioritised by soccer coaches and practitioners aiming to develop multi-directional speed. Although the importance of agility is advocated throughout childhood and adolescence, limited data evidence agility performance at different stages of adolescence. The purpose of this study was to examine differences in multi-directional speed performance in youth soccer players spanning an entire soccer academy. A total of 86 male junior-elite soccer players volunteered to participate. Anthropometric data were collected, alongside performance data from a battery of physical tests including sprinting, jumping, change of direction, reaction time, and agility. Bayesian models using log-likelihoods from posterior simulations of parameter values displayed linear or curvilinear relationships between both chronological and biological age and performance in all tests other than agility and reaction time. For agility and reaction time tests, performance improved until ~14 years of age or the estimated age of peak height velocity whereby arrested development in performance was observed. Our results demonstrate that while most performance skills improve as chronological or biological age increases, measures of agility and reaction time may not. These findings support the notion that agility performance is complex and multifaceted, eliciting unique, challenging physical demands and non-linear development.

Ambulance response times and 30-day mortality: a Copenhagen (Denmark) registry study.

BACKGROUND AND IMPORTANCE: Ensuring prompt ambulance responses is complicated and costly. It is a general conception that short response times save lives, but the actual knowledge is limited. OBJECTIVE: To examine the association between the response times of ambulances with lights and sirens and 30-day mortality. DESIGN: A registry-based cohort study using data collected from 2014-2018. SETTINGS AND PARTICIPANTS: This study included 182 895 individuals who, during 2014-2018, were dispatched 266 265 ambulances in the Capital Region of Denmark. OUTCOME MEASURES AND ANALYSIS: The primary outcome was 30-day mortality. Subgroup analyses were performed on out-of-hospital cardiac arrests, ambulance response priority subtypes, and caller-reported symptoms of chest pain, dyspnoea, unconsciousness, and traffic accidents. The relation between variables and 30-day mortality was examined with logistic regression. RESULTS: Unadjusted, short response times were associated with higher 30-day mortality rates across unadjusted response time quartiles (0-6.39 min: 9%; 6.40-8.60 min: 7.5%, 8.61-11.80 min: 6.6%, >11.80 min: 5.5%). This inverse relationship was consistent across subgroups, including chest pain, dyspnoea, unconsciousness, and response priority subtypes. For traffic accidents, no significant results were found. In the case of out-of-hospital cardiac arrests, longer response times of up to 10 min correlated with increased 30-day mortality rates (0-6.39 min: 84.1%; 6.40-8.60 min: 86.7%, 8.61-11.8 min: 87.7%, >11.80 min: 85.5%). Multivariable-adjusted logistic regression analysis showed that age, sex, Charlson comorbidity score, and call-related symptoms were associated with 30-day mortality, but response time was not (OR: 1.00 (95% CI [0.99-1.00])). CONCLUSION: Longer ambulance response times were not associated with increased mortality, except for out-of-hospital cardiac arrests.

Methods to predict the timing and status of biological maturation in male adolescent soccer players: A narrative systematic review.

The aim of this review was to summarise the methods used to predict and assess maturity status and timing in adolescent, male, academy soccer players. A systematic search was conducted on PubMed, Scopus, Web of Science, CINAHL, Medline and SPORTDiscus. Only experimental studies including male, academy players aged U9-U18 years registered with a professional soccer club were included. The methodological quality of the included studies was assessed using guidelines from the Framework of Potential Biases. Fifteen studies fulfilled our inclusion criteria. Studies were mainly conducted in European countries (n = 12). In total, 4,707 players were recruited across all 15 studies, with an age range of 8-18 years. Five studies were longitudinal, two studies were mixed-method designs and eight studies were cross-sectional. Due to high heterogeneity within the studies, a meta-analysis was not performed. Our findings provided no equivalent estimations of adult height, skeletal age, or age at PHV. Discrepancies were evident between actual and predicted adult height and age at PHV. The Bayley-Pinneau [1952], Tanner-Whitehouse 2 [1983] and Khamis-Roche [1994] methods produced estimates of adult height within 1cm of actual adult height. For age at PHV, both Moore [2015] equations produced the closest estimates to actual age at PHV, and the Fransen [2018] equation correlated highly with actual age at PHV (>90%), even when the period between chronological age and age at PHV was large. Medical imaging techniques (e.g., Magnetic Resonance Imaging, X-Ray, Dual energy X-ray Absorptiometry) demonstrated high intra/inter-rater reliability (ICC = 0.83-0.98) for skeletal maturity assessments. The poor concordance between invasive and non-invasive methods, is a warning to practitioners to not use these methods interchangeably for assessing maturational status and timing in academy soccer players. Further research with improved study designs is required to validate these results and improve our understanding of these methods when applied in this target population.

Men Are from Quartile One, Women Are from? Relative Age Effect in European Soccer and the Influence of Age, Success, and Playing Status.

The relative age effect (RAE) is characterised by an overrepresentation of athletes born earlier in the selection year. Whilst an RAE is consistently evident in male soccer, examinations in female players remain limited. The aim of the present study was to examine the influence of sex, as well as age, success, and playing status in European soccer players. The sample consisted of a total of 6546 soccer players from 55 soccer nations that competed in recent European Championship qualification campaigns. Results indicated an evident RAE in male [p = 0.017] but not female [p = 0.765] players. Male players were over-represented by players born in the first quartile for the U17 [p < 0.001] and U19 [p = 0.001] levels, however, this over-representation did not transfer to senior levels. No RAE was observed at any level for female players. Inside each age group, a slight selection bias towards those born in the first quartile for successful squads was observed but did not significantly differentiate between qualification status for either male or female players. Results from this study highlight the disparity in RAE prevalence between male and female players and raise further questions regarding the value of selecting relatively older players to metrics of success, transition, and selection for senior international soccer.

Developmental activities of professional male British rugby-league players versus controls.

PURPOSE: Many rugby league clubs rely on developing youth athletes into experts in adulthood. One factor that contributes to the attainment of expertise is the activities that athletes engage in across their development. Therefore, the developmental activities of professional male British rugby league players were compared to lesser-skilled players. METHODS: Players who had progressed from youth academies to professional status, those who were released from youth academies, and those who had only played recreationally completed the Participation History Questionnaire. RESULTS: During childhood, professional players accumulated significantly greater amounts of play compared to ex-academy and recreational players, as well as greater coach-led practice compared to ex-academy . During early adolescence, this pattern continued, whereas in late adolescence the professional and ex-academy players accumulated significantly greater amounts of coach-led practice compared to their recreational counterparts. Professional players accumulated more hours in rugby league up to 18 years of age compared to ex-academy players, with both groups accumulating more hours than recreational . The number of other sports engaged in was relatively low across development and did not discriminate between performance levels. CONCLUSION: Findings from this study may inform future practice of talent development systems within rugby league in Britain.

Does anticipation of penalty kicks in soccer transfer across similar and dissimilar sports?

The aim of the present study was to examine whether anticipation skill associated with penalty-kick scenarios is sport-specific, or whether it transfers between sports that have similar elements. A shortened participation history questionnaire was used to identify 97 soccer players, 47 invasion sport players (e.g., rugby), and 72 other sport players (e.g., swimming), as well as skill level (hours of engagement/competition level). These participants completed a video-based temporal occlusion anticipation test that required them to select the destination of the ball across a series of soccer penalty scenarios. Results indicated that the skilled soccer players were more accurate than the skilled and less-skilled invasion sport players and skilled and less-skilled other sport players. Skilled soccer players were also more accurate than the less-skilled soccer players, with less-skilled soccer players exhibiting similar accuracy to both the skilled and less-skilled invasion sport and other sport players indicating that processes associated with anticipation of penalty kicks may be specific to their sport.

SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY AND OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FINDINGS IN WAARDENBURG SYNDROME.

PURPOSE: Waardenburg syndrome (WS) is a rare condition characterized by six main features. It has been previously observed that WS is also associated with hypopigmentation of the choroid through multimodal imaging. To our knowledge, this is the first report of using swept-source optical coherence tomography angiography (OCTA) on a patient with known WS. METHODS: Report of a single case. The swept-source OCT images were captured using Topcon DRI OCT Triton (Topcon, Inc, Tokyo, Japan), whereas swept-source OCTA images were captured by Optovue AngioVue (Optovue, Inc, Fremont, CA) using DualTrack Motion Correction Technology. RESULTS: In this case, OCTA demonstrated evidence of normal vasculature of all layers (superficial, deep, and choricocapillaris), a normal foveal avascular zone measuring 0.267 mm2 in the right eye and 0.307 mm2 in the left eye, and a normal capillary density measuring 49.8% in the right eye and 52.6% in the left eye. CONCLUSION: There are many conditions that may mimic the hypopigmentation of the choroid associated with WS; it has been documented that these similar conditions such as choroidal nevus, choroidal melanoma, and Vogt-Koyanagi-Harada syndrome all demonstrated abnormal OCTA findings. Unlike these conditions, our patient with WS had unremarkable OCTA findings.

Quantification of brain proton longitudinal relaxation (T1 ) in lithium-treated and lithium-naïve patients with bipolar disorder in comparison to healthy controls.

BACKGROUND: Proton longitudinal relaxation (T1 ) is a quantitative MRI-derived tissue parameter sensitive to myelin, macromolecular, iron and water content. There is some evidence to suggest that cortical T1 is elevated in bipolar disorder and that lithium administration reduces cortical T1 . However, T1 has not yet been quantified in separate groups containing lithium-treated patients, lithium-naïve patients, and matched healthy controls. METHODS: Euthymic patients with bipolar disorder receiving lithium (n = 18, BDL) and those on other medications but naïve to lithium (n = 20, BDC) underwent quantitative T1 mapping alongside healthy controls (n = 18, HC). T1 was compared between groups within the cortex, white matter and subcortical structures using regions of interest (ROI) derived from the Desikan-Killiany atlas. Effect sizes for each ROI were computed for BDC vs BDL groups and Bipolar Disorder vs HC groups. RESULTS: No significant differences in T1 were identified between BDL and BDC groups when corrected for multiple comparisons. Patients with bipolar disorder had significantly higher mean T1 in a range of ROIs compared to healthy controls, including bilateral motor, somatosensory and superior temporal regions, subcortical structures and white matter. CONCLUSIONS: The higher T1 values observed in the patients with bipolar disorder may reflect abnormal tissue microstructure. Whilst the precise mechanism remains unknown, these findings may have a basis in differences in myelination, macromolecular content, iron and water content between patients and controls.

Feedback of GPS training data within professional English soccer: a comparison of decision making and perceptions between coaches, players and performance staff.

Purpose: The aim of the study was to examine the perceptions of training data feedback from key stakeholders within the coaching process of professional soccer clubs. A survey assessed the importance of training data towards reflection and decision-making, potential barriers and player preferences.Methods: A total of 176 participants comprising coaches, players and performance staff completed the survey.Results: The training data coaches most commonly identified as wanting to see to support reflection was 'high-intensity' actions and variables recognised by the coach as 'work rate/intensity'. All stake- holders reported training data as at least somewhat important in guiding their coaches' practices, with lack of a common goal and high volumes of information being the main barriers to effective feedback of training data. Players deemed feedback as positive to change their behaviour, with total distance, high-speed running and sprint distances as the information they would most like to see. It would be likely to be looked at via message or pinned up in the changing room.Conclusion: Training data are seen as an impactful and effective tool for use by all key stakeholders. Despite this, its use can be optimised by increasing opportunities for informal reflection, using less information, and improving communication of data.

Confinement Effect on Porosity and Permeability of Shales.

Porosity and permeability are the key factors in assessing the hydrocarbon productivity of unconventional (shale) reservoirs, which are complex in nature due to their heterogeneous mineralogy and poorly connected nano- and micro-pore systems. Experimental efforts to measure these petrophysical properties posse many limitations, because they often take weeks to complete and are difficult to reproduce. Alternatively, numerical simulations can be conducted in digital rock 3D models reconstructed from image datasets acquired via e.g., nanoscale-resolution focused ion beam-scanning electron microscopy (FIB-SEM) nano-tomography. In this study, impact of reservoir confinement (stress) on porosity and permeability of shales was investigated using two digital rock 3D models, which represented nanoporous organic/mineral microstructure of the Marcellus Shale. Five stress scenarios were simulated for different depths (2,000-6,000 feet) within the production interval of a typical oil/gas reservoir within the Marcellus Shale play. Porosity and permeability of the pre- and post-compression digital rock 3D models were calculated and compared. A minimal effect of stress on porosity and permeability was observed in both 3D models. These results have direct implications in determining the oil-/gas-in-place and assessing the production potential of a shale reservoir under various stress conditions.

White matter microstructural properties in bipolar disorder in relationship to the spatial distribution of lithium in the brain.

BACKGROUND: Lithium treatment is associated with an increase in magnetic resonance imaging derived measures of white matter integrity, but the relationship between the spatial distribution of brain lithium and white matter integrity is unknown. METHODS: Euthymic patients with bipolar disorder receiving lithium (n = 12) and those on other medications but naïve to lithium (n = 17) underwent diffusion imaging alongside matched healthy controls (n = 16). Generalised fractional anisotropy (gFA) within white matter was compared between groups using a standard space white matter atlas. Lithium-treated patients underwent novel multinuclear lithium magnetic resonance imaging (7Li-MRI) to determine the relative lithium concentration across the brain. The relationship between 7Li-MRI signal intensity and gFA was investigated at the resolution of the 7Li-MRI sequence in native space. RESULTS: Lithium-treated bipolar disorder and healthy control groups had higher mean white matter gFA than the bipolar disorder group treated with other medications (t = 2.5, p < 0.05; t = 2.7, p < 0.03, respectively). No differences in gFA were found between patients taking lithium and healthy controls (t = 0.02, p = 1). These effects were seen consistently across most regions in the white matter atlas. In the lithium-treated group, a significant effect of the 7Li-MRI signal in predicting the gFA (p < 0.01) was identified in voxels containing over 50% white matter. LIMITATIONS: Cross-sectional evaluation of a relatively small cohort. CONCLUSIONS: The higher gFA values observed in the lithium-treated bipolar disorder group suggests that long-term lithium is associated with greater white matter integrity. Our novel analysis supports this further, showing a positive association between white matter gFA and the spatial distribution of lithium.

Time-resolved synchrotron X-ray micro-tomography datasets of drainage and imbibition in carbonate rocks.

Multiphase flow in permeable media is a complex pore-scale phenomenon, which is important in many natural and industrial processes. To understand the pore-scale dynamics of multiphase flow, we acquired time-series synchrotron X-ray micro-tomographic data at a voxel-resolution of 3.28 µm and time-resolution of 38 s during drainage and imbibition in a carbonate rock, under a capillary-dominated flow regime at elevated pressure. The time-series data library contains 496 tomographic images (gray-scale and segmented) for the complete drainage process, and 416 tomographic images (gray-scale and segmented) for the complete imbibition process. These datasets have been uploaded on the publicly accessible British Geological Survey repository, with the objective that the time-series information can be used by other groups to validate pore-scale displacement models such as direct simulations, pore-network and neural network models, as well as to investigate flow mechanisms related to the displacement and trapping of the non-wetting phase in the pore space. These datasets can also be used for improving segmentation algorithms for tomographic data with limited projections.

Atypical biological kinematics are represented during observational practice.

The present study investigated the effect of stimulus-response compatibility on the representation of atypical biological kinematics during observational practice. A compatible group observed an atypical model that moved rightward, whereas an incompatible group observed an atypical model that moved leftward. Both groups were instructed to observe the model with the intention to later reproduce the movement trajectory. This was examined in a posttest where participants were asked to move rightward with a kinematic profile that matched the atypical kinematics. Compared to a control group that did not engage in practice, and irrespective of whether the stimulus was observed in a spatially compatible or incompatible orientation, participants from both experimental groups reproduced velocity profiles that were comparable and similar to the atypical biological kinematics. Bayesian analysis indicated equality between the 2 experimental groups, thus suggesting comparable sensorimotor processing. Therefore, by rotating the incompatible stimulus by 180 degrees during observational practice, the current study has isolated the processing and representation of atypical biological kinematics to the underlying sensorimotor processes, rather than spatial encoding of peak velocity via processes associated with stimulus-response compatibility. (PsycINFO Database Record

3D 7Li magnetic resonance imaging of brain lithium distribution in bipolar disorder.

Lithium is a major treatment for bipolar disorder and the likelihood of a favourable response may be determined by its distribution in the brain. Lithium can be directly detected by magnetic resonance (MR), but previous 7Li MR spectroscopy studies have demonstrated that this is challenging compared to conventional 1H MR imaging due to the MR properties of the lithium nucleus and its low concentration in brain tissue, as dictated by therapeutic dose. We have tested and implemented a highly efficient balanced steady-state free precession 7Li-MRI method to address these challenges and enable MRI of brain lithium in a short duration scan. We report a 3D 7Li-MRI acquisition with 25 mm isotropic resolution in an 8-min scan that demonstrates heterogeneity in lithium concentration within the brain in subjects with bipolar disorder. This represents the direct imaging of a pharmaceutical agent in its target organ and notably expands the repertoire of techniques available to investigate the effects of lithium in man.

Sensorimotor learning and associated visual perception are intact but unrelated in autism spectrum disorder.

Humans show an astonishing capability to learn sensorimotor behaviours. However, data from sensorimotor learning experiments suggest the integration of efferent sensorimotor commands, afferent sensorimotor information, and visual consequences of a performed action during learning is different in autism, leading to atypical representation of internal action models. Here, we investigated the generalization of a sensorimotor internal action model formed during sensorimotor learning to a different, but associated, visual perception task. Although motor timing was generally less accurate in adults with autism, following practice with feedback both autistic adults, and controls, significantly improved performance of the movement sequence timing task by reducing timing error. In a subsequent perception task, both groups demonstrated similar temporal-discrimination accuracy (autism = 75%; control = 76%). Significant correlations between motor timing error, and temporal-discrimination during a perception task, was found for controls. No significant correlations were found for autistic adults. Our findings indicate that autistic adults demonstrated adaptation by reducing motor timing error through sensorimotor learning. However, the finding of significant correlations between motor timing error and temporal-discrimination accuracy in the control group only suggests sensorimotor processes underpinning internal action model formation operate differently in autism. Autism Res 2018, 11: 296-304. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We showed autistic adults learned a new motor skill, and visually judged moving objects, to a similar level of accuracy as a control group. Unlike the control group, there was no relationship between how well autistic adults learned the motor skill, and how well they judged objects. The lack of a relationship might be one of the reasons autistic adults interact differently in the social world.

Variation of the Contact Time of Droplets Bouncing on Cylindrical Ridges with Ridge Size.

Reducing the contact time between bouncing droplets and an underlying solid surface is relevant to a broad range of industrial applications, such as anti-icing and self-cleaning. Previous work has found that placing cylindrical obstacles on the substrate leads to a reduction in contact time. For obstacles large compared to the drop, this is a result of hydrodynamic coupling between the azimuthal and axial spreading directions. For obstacles small compared to the drop, the reduction in contact time is interpreted as being due to fast retraction along the cylindrical ridge, followed by drop breakup. Here we use simulations to discuss in greater detail the effect of varying the obstacle size on the dynamics of the drop bouncing. We investigate the crossover between the two regimes and explain why the contact time is minimized when the radii of the drop and the cylindrical obstacle are comparable.

Dynamics of snap-off and pore-filling events during two-phase fluid flow in permeable media.

Understanding the pore-scale dynamics of two-phase fluid flow in permeable media is important in many processes such as water infiltration in soils, oil recovery, and geo-sequestration of CO2. The two most important processes that compete during the displacement of a non-wetting fluid by a wetting fluid are pore-filling or piston-like displacement and snap-off; this latter process can lead to trapping of the non-wetting phase. We present a three-dimensional dynamic visualization study using fast synchrotron X-ray micro-tomography to provide new insights into these processes by conducting a time-resolved pore-by-pore analysis of the local curvature and capillary pressure. We show that the time-scales of interface movement and brine layer swelling leading to snap-off are several minutes, orders of magnitude slower than observed for Haines jumps in drainage. The local capillary pressure increases rapidly after snap-off as the trapped phase finds a position that is a new local energy minimum. However, the pressure change is less dramatic than that observed during drainage. We also show that the brine-oil interface jumps from pore-to-pore during imbibition at an approximately constant local capillary pressure, with an event size of the order of an average pore size, again much smaller than the large bursts seen during drainage.

Dynamic fluid connectivity during steady-state multiphase flow in a sandstone.

The current conceptual picture of steady-state multiphase Darcy flow in porous media is that the fluid phases organize into separate flow pathways with stable interfaces. Here we demonstrate a previously unobserved type of steady-state flow behavior, which we term "dynamic connectivity," using fast pore-scale X-ray imaging. We image the flow of N2 and brine through a permeable sandstone at subsurface reservoir conditions, and low capillary numbers, and at constant fluid saturation. At any instant, the network of pores filled with the nonwetting phase is not necessarily connected. Flow occurs along pathways that periodically reconnect, like cars controlled by traffic lights. This behavior is consistent with an energy balance, where some of the energy of the injected fluids is sporadically converted to create new interfaces.