{1124} Deformation Twinning in Commercial Purity Titanium at Room Temperature

This is the accepted manuscript. It is currently embargoed pending publication.Definitive evidence from both electron back-scattered diffraction and transmission electron microscopy is shown for the existence of 1124 twinning as a rare deformation twinning mode in coarse grained commercial purity titanium after room temperature ballistic impact testing at 103 s−1. Non-Schmid-based twin type selection is demonstrated for 1124 and the conjugate 1122 deformation twinning modes in this material within grains where the c-axis is closely aligned to the loading direction. Limited Schmid-based twin variant selection is shown for 1124 and 1122 deformation twinning modes in this material. The occurrence of high area fractions of 1124 twinning has relevance for high strain rate plasticity modelling of grains of textured titanium compressed parallel to their c-axes.This work was supported by the Rolls-Royce plc / EPSRC strategic partnership under EP/H022309/1

Physical activity patterns in youth with intellectual disabilities

The aim of this study was to assess the physical activity (PA) patterns of youth with intellectual disabilities (ID). PA was monitored for 7 days in 70, 5 – 15 year old participants using accelerometers. Thirty two participants were included in the final analysis. Habitual PA and the number of continuous bouts accrued for a range of bout lengths (5-600 seconds) for light (LPA), moderate (MPA) and vigorous (VPA) intensity PA were calculated. Multivariate analysis of covariance was used to assess differences in the number of continuous bouts by sex, age, ID group and between week and weekend days. Participants exhibited short sporadic bursts of activity. The number of continuous bouts decreased as the intensity and duration increased. Few differences in PA patterns were reported by sex, ID group, age group and between week and weekend days, possibly due to the generally low PA levels within this population

Physical activity and play behaviours in children and young people with intellectual disabilities: A cross-sectional observational study

The benefits of physical activity and active play for children and young people are well established. However, there is a lack of physical activity research involving children and young people with intellectual disabilities. This study investigated habitual physical activity and recess play behaviour in 70 5- to 15-year-old participants with intellectual disabilities using objective methods (accelerometers) and systematic observation techniques. Results showed that few children were active enough to benefit their physical health (23% of the cohort). No differences in habitual physical activity, sedentary behaviour, or recess play behaviours were observed between boys and girls. Participants spent most of their recess time alone or playing in small groups, with no participants engaging in large group play. Older participants spent more recess time playing in small groups rather than playing alone and participants with Autistic Spectrum Disorder spent more time engaged in active pursuits and less time standing than non-Autism Spectrum Disorder participants. Positive correlations were observed between time spent alone and physical activity. These findings contrast with those typically observed in a mainstream school setting. In conclusion, interventions designed from formative research are needed to promote physical activity within this population. Implications for school psychologists are discussed

Very high strain rate deformation twinning behaviour of Ti–6Al–4V

Equiaxed fine-grained and coarse-grained samples of h.c.p. α phase Ti–6Al–4V with trace amounts of retained b.c.c. β phase were ballistically tested at room temperature. The deformed microstructures were characterised by electron back scattered diffraction. The extensive deformation twinning observed in the α phase in both samples was limited to the {1 0 -1 2} and {1 1 -2 1} tensile twinning modes. These two deformation twinning types have very different morphologies: thin {1 1 -2 1} deformation twins span multiple α phase grain boundaries, while the wider {1 0 -1 2} deformation twins are usually limited to individual grains, reorienting almost entire grains to a twinned orientation. Both {1 0 -1 2} and {1 1 -2 1} deformation twins are able to propagate across low angle α lath boundaries, but only the {1 1 -2 1} deformation twinning types can propagate across high angle α grain boundaries.This work was supported by the Rolls-Royce plc/EPSRC strategic partnership under EP/H022309/1

Parental perceptions on children's out-of-school physical activity and family-based physical activity interventions

This study explored parents' physical activity knowledge and perceptions of children’s out-of school physical activity to formatively contribute to a family-based intervention design. Parents were largely unaware of the UK child physical activity guidelines and whether their child achieved the guidelines daily. Physical activity for many parents was attributed to healthy weight status, and the neighbourhood environment was perceived as unconducive to children’s outdoor play which consequently increased the attractiveness of adult supervised organised activities. Family-based intervention engagement was considered as an important opportunity to increase physical activity knowledge, family time, and receive feedback on activity behaviours. Parental concerns related to intervention content and logistic and timing barriers. Consulting with parents in a formative sense prior to familial physical activity intervention facilitates intervention content to be aligned with family-specific perceptions and needs, and offers opportunities to communicate the relevance of programs to parents. This may aid subsequent intervention recruitment and engagement

Effect of a family focused active play intervention on sedentary time and physical activity in preschool children

Background: Early childhood provides a window of opportunity for the promotion of physical activity. Given the limited effectiveness of interventions to date, new approaches are needed. Socio-ecological models suggest that involving parents as intervention targets may be effective in fostering healthier lifestyles in children. This study describes the effectiveness of a family-focused ‘Active Play’ intervention in decreasing sedentary time and increasing total physical activity in preschool children. Method: Seventy-seven families were recruited from 8 randomly selected SureStart children’s centres in the North West of England. Centres were randomly assigned to either an intervention (n = 4) or a comparison group (n = 4). Parents and children in the intervention group received a 10-week active play programme delivered by trained active play professionals; this included an activity and educational component. Families in the comparison group were asked to maintain their usual routine. Each participating parent and child wore a uni-axial accelerometer for 7 days at baseline and post-test. Week and weekend day sedentary time and total physical activity adjusted for child- and home- level covariates were analysed using multilevel analyses. Results: Significant intervention effects were observed for sedentary time and physical activity for both week and weekend days. Children in the intervention group engaged in 1.5% and 4.3% less sedentary time during week and weekend days, respectively and 4.5% and 13.1% more physical activity during week and weekend days, respectively than children in the comparison group. Parent’s participation in sport and their physical activity levels, child’s sex, availability of media in the home and attendance at organised activities were significant predictors of sedentary time and physical activity in this age group. Conclusion: A 10-week family focused active play intervention produced positive changes in sedentary time and total physical activity levels in preschool children. Specific covariates were identified as having a significant effect on the outcome measures. Moreover, children whose parents were active engaged in less sedentary time and more physical activity suggesting that parent’s activity habits are mediators of physical activity engagement in this age group. Keywords: Preschool children, Paren

“I Wasn’t Sure What It Meant to be Honest”—Formative Research towards a Physical Literacy Intervention for Preschoolers

Physical literacy (PL) as a concept is important in developing lifelong physical activity; however, there is little research exploring how PL can be developed during the preschool years. This two-phase qualitative study sought the insights of academics/expert practitioners and preschool staff towards PL in order to inform the design of future preschool PL interventions. Phase One comprised of nine semi-structured interviews with experts in the field of children’s physical activity and/or PL. Interview topics included perspectives on the concept of PL and recommendations for interventions targeted at improving preschool PL. Phase Two consisted of focus groups with practitioners from four local children’s centres. Focus groups explored perspectives on the feasibility and acceptability of proposed PL interventions. Interviews and focus groups were analysed by thematic analysis and means of representation, respectively. Findings revealed that whilst there was limited understanding about the concept of PL among preschool educators, knowledge of child development was evident and that all participants agreed that there was a need for further training for practitioners. Perceived barriers to promoting PL noted by practitioners included funding, policy, curricular priorities, parental opinions, and the preschool environment. It was recommended that interventions should be: (i) designed using a participatory approach including all key stakeholders, (ii) conducted over the long term, and (iii) incorporate opportunities for children to engage in free and outdoor play. Furthermore, any intervention should be flexible to allow for variation between children’s centres, aligned to current policy/children’s centre targets and provide training and resources in order to overcome perceived barriers.</jats:p

Comparison of children's free-living physical activity derived from wrist and hip raw accelerations during the segmented week.

This study assessed children's physical activity (PA) levels derived from wrist-worn GENEActiv and hip-worn ActiGraph GT3X+ accelerometers and examined the comparability of PA levels between the two devices throughout the segmented week. One hundred and twenty-nine 9-10-year-old children (79 girls) wore a GENEActiv (GAwrist) and ActiGraph GT3X+ (AGhip) accelerometer on the left wrist and right hip, respectively, for 7 days. Mean minutes of light PA (LPA) and moderate-to-vigorous PA (MVPA) per weekday (whole-day, before-school, school and after-school) and weekend day (whole-day, morning and afternoon-evening) segments were calculated, and expressed as percentage of segment time. Repeated measures analysis of variance examined differences in LPA and MVPA between GAwrist and AGhip for each time segment. Bland-Altman plots assessed between-device agreement for LPA and MVPA for whole weekday and whole weekend day segments. Correlations between GAwrist and AGhip were weak for LPA (r = 0.18-0.28), but strong for MVPA (r = 0.80-0.86). LPA and MVPA levels during all weekday and weekend day segments were significantly higher for GAwrist than AGhip (p < 0.001). The largest inter-device percent difference of 26% was observed in LPA during the school day segment. Our data suggest that correction factors are needed to improve raw PA level comparability between GAwrist and AGhip

Microstructural characterisation of metallic shot peened and laser shock peened Ti–6Al–4V

A detailed analysis has been conducted of Ti–6Al–4V processed by metallic shot peening and laser shock peening. Analysis by incremental hole drilling, electron backscattered diffraction microscopy, transmission electron microscopy and transmission Kikuchi diffraction microscopy is evaluated and discussed. The results of this analysis highlight the very different dislocation structures in surfaces processed by these two techniques. Transmission Kikuchi diffraction also has been used to evaluate sub-grains generated by laser shock peening. A notable feature of material processed by laser shock peening is the almost complete absence of deformation twinning, contrasting with the frequent observation of extensive deformation twinning observed in the material processed by metallic shot peening.This work was supported by the Rolls-Royce plc/EPSRC strategic partnership under EP/H022309/1

Exploring teachers' perceptions on physical activity engagement for children and young people with intellectual disabilities

Aim: To explore teacher’s perceptions of barriers and facilitators to physical activity, including enabling, reinforcing and predisposing factors amongst children and young people (CYP) with intellectual disabilities (ID). Method and procedures: The Youth Physical Activity Promotion (YPAP) model was used to inform semi-structured focus groups to explore physical activity of CYP with ID. Participants were 23 (9 male) teachers and teaching assistants, from 3 special educational needs (SEN) schools (1 = Primary, 2 = Secondary) within North West England. Three focus groups were held with between 6 and 8 participants, audio and video recorded and data transcribed. Data were inductively and deductively analysed using Nvivo and represented through pen profiles. Results: Three pen profiles were developed and structured around YPAP model to display themes within the data. Enabling factors (facilities (n=23) and activity type (n=39)); reinforcing factors (influences of peers (n=23), family (n=10) and teachers (n=19) to physical activity engagement); predisposing factors (healthy lifestyle (n=15), enjoyment of physical activity (n=14), adaptations for physical activity (n=10), structured play (n=10), effects of disability on physical activity (n=8) and the CYPs attitudes towards physical activity (n=8)). Conclusion: CYP with ID enjoy engaging in physical activity, particularly activities that are of a fun and unstructured nature which allow for progression of skills and promote independence. Participants recognised that they, as teachers, had an influence on the CYP’s physical activity engagement, however suggested that parents have the most influential role. Similar to previous research, participants noted that CYP with ID had a lack of understanding as regards the importance of physical activity engagement and its benefits to health. It is suggested a strong home-school link for CYP within SEN schools could prove to be a key facilitator for active and healthy lifestyles education and choices