Motor skill competence and moderate- and vigorous-intensity physical activity: a linear and non-linear cross-sectional analysis of eight pooled trials.

BACKGROUND: Few studies have examined the relationship between motor skill competence and device-measured physical activity in large samples and none have used non-linear modelling. This study assessed the linear and non-linear associations between motor skill competence and physical activity in children using pooled data from eight studies. METHODS: Cross-sectional ActiGraph accelerometer and motor skills competence data from 988 children (50.8% boys) aged 3-11 years were included. Total, object control and locomotor skill competence were assessed using the Test of Gross Motor Skill Development. Linear mixed models were fitted to examine linear associations between motor skill competence and physical activity. Then, restricted cubic splines models were used to assess potential non-linear relationships. Interactions by sex and age were assessed. RESULTS: There was evidence of positive linear associations between total skill, and object control and locomotor skills, with moderate- and vigorous-intensity physical activity; however, the associations with total skill competence and object control better fitted a non-linear model. Non-linear models indicated associations were positive but relatively weak in the low to mid ranges of TGMD/object control scores but at high ranges (~ > 70 out of 100/ and ~ 35 out of 50) the association strength increased for both moderate- and vigorous-intensity physical activity. There were sex interactions for locomotor skills only, specifically for vigorous activity with boys having a stronger positive association than girls. CONCLUSIONS: There appears to be a threshold for object control skill proficiency that children need to reach to enhance their physical activity levels which provides support for a motor skill "proficiency barrier". This provides a tangible benchmark for children to achieve in motor competence programs.

Dynamical independence: Discovering emergent macroscopic processes in complex dynamical systems.

We introduce a notion of emergence for macroscopic variables associated with highly multivariate microscopic dynamical processes. Dynamical independence instantiates the intuition of an emergent macroscopic process as one possessing the characteristics of a dynamical system "in its own right," with its own dynamical laws distinct from those of the underlying microscopic dynamics. We quantify (departure from) dynamical independence by a transformation-invariant Shannon information-based measure of dynamical dependence. We emphasize the data-driven discovery of dynamically independent macroscopic variables, and introduce the idea of a multiscale "emergence portrait" for complex systems. We show how dynamical dependence may be computed explicitly for linear systems in both time and frequency domains, facilitating discovery of emergent phenomena across spatiotemporal scales, and outline application of the linear operationalization to inference of emergence portraits for neural systems from neurophysiological time-series data. We discuss dynamical independence for discrete- and continuous-time deterministic dynamics, with potential application to Hamiltonian mechanics and classical complex systems such as flocking and cellular automata.

Effects on mortality of shielding clinically extremely vulnerable patients in Liverpool, UK, during the COVID-19 pandemic.

OBJECTIVE: This study evaluates the impact of England's COVID-19 shielding programme on mortality in the City of Liverpool in North West England. STUDY DESIGN: Shielded and non-shielded people are compared using data from linked routine health records on all people registered with a general practitioner in Liverpool from April 2020 to June 2021. METHODS: A discrete time hazard model and interactions between the shielding status and the periods of higher risk of transmission are used to explore the effects of shielding across the major phases of the COVID-19 pandemic. RESULTS: Shielding was associated with a 34% reduction in the risk of dying (HR = 0.66, 95% CI: 0.58 to 0.76) compared with a propensity-matched non-shielded group. Shielding appeared to reduce mortality during the first and third waves, but not during the second wave, where shielding was not mandated by the government. The effects were similar for males and females, but more protective for those living in the least deprived areas of Liverpool. CONCLUSIONS: It is likely that the shielding programme in Liverpool saved lives, although this seems to have been a little less effective in more deprived areas. A comprehensive programme for identifying vulnerable groups and providing them with advice and support is likely to be important for future respiratory virus pandemics. Additional support may be necessary for socio-economically disadvantaged groups to avoid increased inequalities.

Development of ELIP to Assess Physical Literacy for Emerging Adults: A Methodological and Epistemological Challenge.

Purpose: Following increased interest in physical literacy (PL), development of appropriate tools for assessment has become an important next step for its operationalization. To forward the development of such tools, the objective of this study was to build the foundations of the Évaluation de la Littératie Physique (ELIP), designed to help reduce existing tensions in approaches to PL assessment that may be resulting in a low uptake into applied settings. Methods: We followed two steps: (1) the development of the first version of ELIP by deploying a Delphi method (n = 30); and (2) the modification of items through cognitive interviews with emerging adults (n = 32). Results: The expert consensus highlighted four dimensions of PL to be assessed-physical; affective; cognitive; and social-with new perspectives, including a preference for broad motor tests over fitness. Conclusion: Results offer new insights into the assessment of emerging adults' PL, but ELIP still requires further work concerning validity, reliability, and sensitivity.

How Do Physical Activity and Sedentary Behaviour Affect Motor Competence in Children with Autism Spectrum Disorder Compared to Typically Developing Children: A Pilot Study.

Older children with Autism Spectrum Disorder (ASD) have high levels of motor impairment, however we are unsure if similar patterns exist in young children. This study aimed to investigate motor competence in four-to-seven-year-old children with (n = 17) and without (n = 17) ASD. A series of ANOVAS indicated children with ASD performed significantly poorer on all measures of motor competence, except MABC-2 manual dexterity and ball skills subscales. Results indicate that moderate-to-vigorous physical activity (PA) and sedentary behaviour (SB) may influence motor competence, regardless of diagnosis. Establishing appropriate levels of engagement in moderate-to-vigorous PA and SB during early school years is important for the development of all children and may be an important early intervention avenue for motor impairment in children with ASD.

Effects of classroom-based active breaks on cognition, sitting and on-task behaviour in children with intellectual disability: a pilot study.

BACKGROUND: Classroom-based active breaks can help typically developing children reduce sitting, increase physical activity and improve cognitive functions and on-task behaviour. Yet, this strategy has not been tested in children with intellectual disability (ID) - a population who are insufficiently active. This study aimed to investigate the effects of a 5-week active breaks intervention on cognitive functions and on-task behaviour in schoolchildren with ID. METHODS: Twenty-four children, aged between 8 and 12 years (37.5% girls), were recruited. Children's cognitive functions (response inhibition, lapses of attention, interference and working memory) were measured at baseline and end of trial using computer-based tests. Sitting, standing and movement patterns were assessed with inclinometers, and on-task behaviour was directly observed in the classroom before and after active breaks, at baseline, mid-trial and end of trial. Linear mixed models were used to investigate the intervention effects on cognitive functions and sedentary patterns; generalised linear mixed models were used to analyse on-task behaviour data. RESULTS: A significant time × group interaction was found for working memory favouring the intervention (B = 11.56, 95% confidence interval [1.92, 21.21]). No significant effects were found in relation to the other measures of children's cognition or on-task behaviour. Stepping time and bouts of sitting were positively affected. CONCLUSIONS: Classroom-based active breaks can increase physical activity and reduce sedentary behaviour in children with ID and might also benefit their working memory. Further research is required to clarify the effects on cognition and to investigate whether this strategy has other benefits in this population.

The effect of osteopathic manual therapy with breathing retraining on cardiac autonomic measures and breathing symptoms scores: A randomised wait-list controlled trial.

BACKGROUND: Breathing retraining and manual therapy (MT), delivered independently or together, influence autonomic activity, and improve symptoms in patients with chronic conditions. This study evaluated the effects of breathing retraining and osteopathic MT on cardiac autonomic measures and breathing symptoms during spontaneous breathing in healthy active adults. METHODS: Participants (n = 18) received breathing retraining and four, weekly manual therapy sessions, randomised to start immediately, or after 6-week delay. Heart-rate (HR) variability was assessed as a 7-day average of waking 6-min electrocardiograms, using time (logarithm of root-mean-square of successive differences; LnRMSSD) and frequency domain (logarithm of high-frequency; LnHF) measures. Recordings were taken before, one week following intervention or delay, and then following the later intervention for those with delayed starts. Changes were compared between those who received and had yet to receive the intervention, and before and after treatment for the whole cohort. RESULTS: Following the intervention, HR-variability measures increased 4% overall (Effect Sizes: 1.0-1.1) for the whole cohort. Between-group analyses showed that the immediate-start group increased more than the delayed start group: LnRMSSD 0.27 (0.02-0.52; 95%CI) ln.ms, and LnHF 0.41 (-0.01-0.84) ln.ms2 for immediate start; compared with LnRMSSD -0.09 (-0.29-0.11) ln.ms, and LnHF -0.19 (-0.59-0.22) ln.ms2 (P = 0.02-0.03 for interaction) for delayed start. Resting HR decreased following intervention in the whole cohort (Effect Size -0.8; P = 0.02). CONCLUSION: A 6-week osteopathic treatment consisting of breathing retraining and MT is beneficial in raising HR-variability compared to no treatment, and may induce favourable (parasympathetic over sympathetic) autonomic modulation. TRIAL REGISTRATION: ACTRN12614001119684.

A new approach to comprehensively evaluate the morphological properties of the human femoral head: example of application to osteoarthritic joint.

Osteoarthritis affects the morphological properties of the femoral head. The goal of this study was to develop a method to elucidate whether these changes are localised to discrete regions, or if the reported trends in microstructural changes may be identified throughout the subchondral bone of the human femoral head. Whole femoral heads extracted from osteoarthritic (n = 5) and healthy controls (n = 5) underwent microCT imaging 39 µm voxel size. The subchondral bone plate was virtually isolated to evaluate the plate thickness and plate porosity. The trabecular bone region was divided into 37 volumes of interest spatially distributed in the femoral head, and bone morphometric properties were determined in each region. The study showed how the developed approach can be used to study the heterogeneous properties of the human femoral head affected by a disease such as osteoarthritis. As example, in the superior femoral head osteoarthritic specimens exhibited a more heterogeneous micro-architecture, with trends towards thicker cortical bone plate, higher trabecular connectivity density, higher trabecular bone density and thicker structures, something that could only be observed with the newly developed approach. Bone cysts were mostly confined to the postero-lateral quadrants extending from the subchondral region into the mid trabecular region. Nevertheless, in order to generalise these findings, a larger sample size should be analysed in the future. This novel method allowed a comprehensive evaluation of the heterogeneous micro-architectural properties of the human femoral head, highlighting effects of OA in the superior subchondral cortical and trabecular bone. Further investigations on different stages of OA would be needed to identify early changes in the bone.

Information flow in finite flocks.

We explore information flow in finite active matter flocks by simulating the canonical Vicsek model and estimating the flow of information as a function of noise (the variability in the extent to which each animal aligns with its neighbours). We show that the global transfer entropy for finite flocks not only fails to peak near the phase transition, as demonstrated for the canonical 2D Ising model, but remains constant from the transition throughout the entire ordered regime to very low noise values. This provides a foundation for future study regarding information flow in more complex models and real-world flocking data.

Musculoskeletal consultations from childhood to adulthood: a longitudinal study.

BACKGROUND: The Global Burden of Disease reports indicate that musculoskeletal conditions are important causes of disability worldwide. Such conditions may originate in childhood, but studies investigating changes longitudinally and from childhood to adulthood are infrequent. METHODS: Nine birth cohorts of children (starting at ages 7-15 years) were followed. Participants were identified from Consultations in Primary Care Archive, an electronic health record database of 11 English general practices. Musculoskeletal consultation prevalence figures were calculated, and reasons for consultation evaluated. RESULTS: Annual musculoskeletal consultation prevalence was similar across cohorts for each age. Prevalence increased from 6 to 16% between ages 7 and 22 and was higher in males until age 15, after which prevalence was higher in females. Pain was the most common reason for consultation. Back pain consultations increased from 1 consultation/1000 7 year olds to 84 consultations/1000 22 year olds. Lower limb pain consultations increased from 21 consultations/1000 7 year olds to 56 consultations/1000 22 year olds. CONCLUSIONS: This study shows that from childhood, individuals are more likely to seek healthcare for musculoskeletal consultations as they age, but rates are not increasing over time. Changes in consultation rates by age, gender and pain region may inform studies on the development of chronic musculoskeletal pain over the life-course.

Young Children with ASD Participate in the Same Level of Physical Activity as Children Without ASD: Implications for Early Intervention to Maintain Good Health.

Primary-school-aged children and adolescents with autism spectrum disorder (ASD) are reported to engage in lower levels of moderate-to-vigorous physical activity (MVPA) compared to typically developing (TD) children (Jones et al. in PLoS ONE, 12(2):1-23, 2017). Levels of MVPA in young children with ASD remain unclear. This study aimed to investigate MVPA in 4-to-7-year-old children with (n = 37) and without (n = 40) ASD, to determine if MVPA is related to ASD diagnosis; and examine correlates to better inform interventions. Results indicated children with ASD engage in the same levels of MVPA as TD children. Future studies need to further explore MVPA in children with ASD over time to uncover when the divergence in MVPA levels occur and what factors may be associated.

Validity and feasibility of an obstacle course to assess fundamental movement skills in a pre-school setting.

Failure to master age-appropriate fundamental movement skills (FMS) at a young age can limit motor skill competence affecting health. Assessments often have issues with feasibility and implementation in a field setting. As such, the purpose of this study was to investigate the validity and feasibility of the Athletic Skills Track (AST), in a pre-school setting. For the validation study sixty-five 3-6 year old children (25 boys and 40 girls) from five pre-schools across Adelaide, Australia participated. Correlations and linear regression analysis (adjusted for age and gender) were used to investigate the association between the time to complete the AST and the raw score of the Test of Gross Motor Development 2 (TGMD-2). For the feasibility study pre-school staff completed a semi-structured interview regarding the feasibility of the AST. The AST took less than a minute per child and the TGMD-2 around 20 minutes for two children. There was a strong negative correlation (r = -0.63, p < 0.01) between the AST scores and the TGMD-2 scores. All five staff reported strengths of the AST to be its short administration time, setup and appropriateness. These results suggest that the AST could be a feasible and valid method of FMS assessment in Australian pre-schools.

Modeling children's development in gross motor coordination reveals key modifiable determinants. An allometric approach.

Children change their body size, shape, and gross motor coordination (GMC) as they grow. Further, GMC is expected to link to changes in children's body size, physical activity (PA), and physical fitness (PF). The objective was to model GMC changes in children followed longitudinally and to investigate associations between these changes and PA and PF levels. A total of 245 children (122 girls) were observed at 6 years of age and followed annually until 9 years. A sequence of allometric models was fitted, that is, 1. body mass, stature, and PA; 2. addition of four PF tests; 3. addition of four more PF tests. In Model 1, changes in GMC are nonlinear, and body mass (-0.60 ± 0.07, P < .001) and stature (2.91 ± 0.35, P < .001) parameter estimates were significant suggesting children with a more linear body size/shape showed higher GMC performances. Girls tend to outperform boys across time, and PA was not associated with GMC changes. Model 2 fitted the data better, and the PF tests (handgrip, standing long jump, 50-yard dash, and shuttle run) were significantly linked to GMC change. In Model 3, adding the remaining PF tests did not change the order of any factors importance. The greatest GMC changes were achieved by children whose body size/shape has an ectomorphic dominance across the years. Considering that leaner and physically fitter children tended to be more coordinated, physical education should also focus on PF development in components related to muscular strength, speed, agility, and aerobic capacity, along with nutritional education to reduce fat mass.

Applying quantitative bias analysis to estimate the plausible effects of selection bias in a cluster randomised controlled trial: secondary analysis of the Primary care Osteoarthritis Screening Trial (POST).

BACKGROUND: Selection bias is a concern when designing cluster randomised controlled trials (c-RCT). Despite addressing potential issues at the design stage, bias cannot always be eradicated from a trial design. The application of bias analysis presents an important step forward in evaluating whether trial findings are credible. The aim of this paper is to give an example of the technique to quantify potential selection bias in c-RCTs. METHODS: This analysis uses data from the Primary care Osteoarthritis Screening Trial (POST). The primary aim of this trial was to test whether screening for anxiety and depression, and providing appropriate care for patients consulting their GP with osteoarthritis would improve clinical outcomes. Quantitative bias analysis is a seldom-used technique that can quantify types of bias present in studies. Due to lack of information on the selection probability, probabilistic bias analysis with a range of triangular distributions was also used, applied at all three follow-up time points; 3, 6, and 12 months post consultation. A simple bias analysis was also applied to the study. RESULTS: Worse pain outcomes were observed among intervention participants than control participants (crude odds ratio at 3, 6, and 12 months: 1.30 (95% CI 1.01, 1.67), 1.39 (1.07, 1.80), and 1.17 (95% CI 0.90, 1.53), respectively). Probabilistic bias analysis suggested that the observed effect became statistically non-significant if the selection probability ratio was between 1.2 and 1.4. Selection probability ratios of > 1.8 were needed to mask a statistically significant benefit of the intervention. CONCLUSIONS: The use of probabilistic bias analysis in this c-RCT suggested that worse outcomes observed in the intervention arm could plausibly be attributed to selection bias. A very large degree of selection of bias was needed to mask a beneficial effect of intervention making this interpretation less plausible.

Imaging features of myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPNs) are a heterogeneous group of haematological disorders including polycythaemia vera (PV), essential thrombocythaemia (ET), primary myelofibrosis (PMF), and chronic myeloid leukaemia (CML). These disorders show large overlap in genetic and clinical presentations, and can have many different imaging manifestations. Unusual thromboses, embolic events throughout the systemic or pulmonary vasculature, or osseous findings can often be clues to the underlying disease. There is limited literature about the imaging features of these disorders, and this may result in under-diagnosis. Multiple treatments are available for symptom control, and the development of multiple new pharmacological inhibitors has significantly improved morbidity and prognosis. Knowledge of these conditions may enable the radiologist to suggest an MPN as a possible underlying cause for certain imaging findings, particularly unexplained splanchnic venous thrombosis, i.e. in the absence of chronic liver disease or pancreatitis. The aim of the present review is to outline using examples the different categories of MPN and illustrate the variety of radiological findings associated with these diseases.

Validity and reliability of a pictorial instrument for assessing perceived motor competence in Portuguese children.

BACKGROUND: It is important to assess young children's perceived Fundamental Movement Skill (FMS) competence in order to examine the role of perceived FMS competence in motivation toward physical activity. Children's perceptions of motor competence may vary according to the culture/country of origin; therefore, it is also important to measure perceptions in different cultural contexts. The purpose was to assess the face validity, internal consistency, test-retest reliability and construct validity of the 12 FMS items in the Pictorial Scale for Perceived Movement Skill Competence for Young Children (PMSC) in a Portuguese sample. METHODS: Two hundred one Portuguese children (girls, n = 112), 5 to 10 years of age (7.6 ± 1.4), participated. All children completed the PMSC once. Ordinal alpha assessed internal consistency. A random subsamples (n = 47) were reassessed one week later to determine test-retest reliability with Bland-Altman method. Children were asked questions after the second administration to determine face validity. Construct validity was assessed on the whole sample with a Bayesian Structural Equation Modelling (BSEM) approach. The hypothesized theoretical model used the 12 items and two hypothesized factors: object control and locomotor skills. RESULTS: The majority of children correctly identified the skills and could understand most of the pictures. Test-retest reliability analysis was good, with an agreement ration between 0.99 and 1.02. Ordinal alpha values ranged from acceptable (object control 0.73, locomotor 0.68) to good (all FMS 0.81). The hypothesized BSEM model had an adequate fit. CONCLUSIONS: The PMSC can be used to investigate perceptions of children's FMS competence. This instrument can also be satisfactorily used among Portuguese children.

Missing the target: DNAk is a dominant epitope in the humoral immune response of channel catfish (Ictalurus punctatus) to Flavobacterium columnare.

Vaccination remains a viable alternative for bacterial disease protection in fish; however additional work is required to understand the mechanisms of adaptive immunity in the channel catfish. To assess the humoral immune response to Flavobacterium columnare; a group of channel catfish were first immunized with F. columnare LV-359-01 cultured in iron-depleted media, before being challenged with wild type F. columnare LV-359-01. The immunization protocol did not confer increased protection against F. columnare; however both control and immunized responders generated serum and skin IgM antibodies against F. columnare proteins. Western blot analyses of individuals from both groups showed that IgM antibodies were generated to the same 70 kDa extracellular protein, which was identified to be the bacterial chaperonin protein DNAk. Antibodies generated were cross reactive to DNAk proteins found in other gram negative bacteria. Our data suggests that DNAk is the dominant epitope in the channel catfish B-cell response to F. columnare.