Shear and delamination behaviour of basal planes in Zr3AlC2 MAX phase studied by micromechanical testing

The mechanical properties of layered, hexagonal-structured MAX phases often show the combined merits of metals and ceramics, making them promising material candidates for safety critical applications. While their unique mechanical performance largely arises from the crystal structure, the effect of chemistry on the properties of these materials remains unclear. To study this, here we employed two in situ electron microscope small scale testing approaches to examine the micromechanical properties of Zr3AlC2, and compared the results with the properties of Ti3SiC2: we used micropillar compression tests to measure basal slip strength, and double cantilever beam splitting tests to evaluate fracture energy for basal plane delamination. We observed distinct and systematic differences in these measured properties between Zr3AlC2 and Ti3SiC2, where Zr3AlC2 appeared to be stronger but more brittle at the microscale, and discussed the implications of the results in the selection, design, and engineering of MAX phases for targeted engineering applications

A multilevel perspective of transition to a circular economy with particular reference to a community renewable energy niche

This article is an attempt to look into the processes involved in achieving full system transition to a circular economy (CE) through the development of niche activities. Based on a case study relating to a community renewable energy (CRE) niche, the article argues that for transition to take hold and make progress, the socio-technical regimes underpinning the system of a linear economy would need to be disrupted through the agency of niches that bring forth radical innovations across a spectrum of activities. This argument is explored through a case study from the energy sector in Scotland. A Delphi study is conducted to assess the success of the Scottish Government in progressing CRE as a niche aimed at disrupting the incumbent fossil-based energy regime. The study finds that despite the commitment of the Scottish Government to empower, nurture and shield CRE as a niche, there is no clear evidence as yet to show whether these actions have achieved their desired effect of enabling the CRE niche to play a disruptive role. The article also underscores the need for methodological refinement to enhance the robustness of the data used in the evaluation of policy efforts in niche development as a strategy for transition to CE

Lights, Camera...Citizen Science: Assessing the Effectiveness of Smartphone-Based Video Training in Invasive Plant Indentification

The rapid growth and increasing popularity of smartphone technology is putting sophisticated data-collection tools in the hands of more and more citizens. This has exciting implications for the expanding field of citizen science. With smartphonebased applications (apps), it is now increasingly practical to remotely acquire high quality citizen-submitted data at a fraction of the cost of a traditional study. Yet, one impediment to citizen science projects is the question of how to train participants. The traditional ‘‘in-person’’ training model, while effective, can be cost prohibitive as the spatial scale of a project increases. To explore possible solutions, we analyze three training models: 1) in-person, 2) app-based video, and 3) app-based text/images in the context of invasive plant identification in Massachusetts. Encouragingly, we find that participants who received video training were as successful at invasive plant identification as those trained in-person, while those receiving just text/images were less successful. This finding has implications for a variety of citizen science projects that need alternative methods to effectively train participants when in-person training is impractical

Co-production of an educational package for the universal human papillomavirus (HPV) vaccination programme tailored for schools with low uptake:A participatory study protocol

AIM: To co-produce with young people an educational package about the human papillomavirus (HPV) vaccine that is tailored to increase vaccine uptake in schools and populations with lower uptake. INTRODUCTION: Persistent infection with HPV can result in cancers affecting men and especially women. From September 2019, the English-schools-based HPV vaccination programme was expanded to include young men (in addition to young women) aged 12-13 years. Some young people attending schools with lower uptake of the vaccine have unmet information needs. We hypothesise that mechanisms to address information needs and increase young people's autonomy in consent procedures will result in higher uptake. METHODS AND ANALYSIS: The Medical Research Council's framework for development and evaluation of complex interventions will inform intervention development. Recruitment of young people aged 12-15 years and key stakeholders (National Health Service commissioners, school staff, immunisation nurses and youth workers/practitioners) will be facilitated through existing links with healthcare organisations, schools and youth organisations in areas with lower uptake of the HPV vaccination programme. The proposed research will comprise three phases: (1) a rapid review of adolescent immunisation materials and preliminary qualitative interviews with young people and key stakeholders, (2) theory development and co-production of HPV vaccine communication materials through an iterative process with young people and (iii) testing delivery mechanisms and acceptability of the educational package in four schools with lower uptake. ETHICS AND DISSEMINATION: The University of Bristol's Faculty of Health Sciences and London School of Hygiene and Tropical Medicine's Research Ethics Committees provided approvals for the study. A dissemination event for young people and key stakeholders and webinar with the National Immunisation Network will be organised. The study findings will be published in peer-reviewed journals and presented at conferences. Recommendations for a future larger scale study will be made

The effects of a single whole-body cryotherapy exposure on physiological, performance and perceptual responses of professional academy soccer players following repeated sprint exercise

In professional youth soccer players, the physiological, performance and perceptual effects of a single whole body cryotherapy (WBC) session performed shortly after repeated sprint exercise were investigated. In a randomized, counter-balanced and crossover design, 14 habituated English Premier League academy soccer players performed 15 x 30 m sprints (each followed by a 10 m forced deceleration) on two occasions. Within 20 min of exercise cessation, players entered a WBC chamber (Cryo: 30 s at -60°C, 120 s at -135°C) or remained seated (Con) indoors in temperate conditions (~25°C). Blood and saliva samples, peak power output (countermovement jump) and perceptual indices of recovery and soreness were assessed pre-exercise and immediately, 2 h and 24 h post exercise. When compared to Con, a greater testosterone response was observed at 2 h (+32.5 ± 32.3 pg·ml-1, +21%) and 24 h (+50.4 ± 48.9 pg·ml-1, +28%) post-exercise (both P=0.002) in Cryo (trial x treatment interaction: P=0.001). No between trial differences were observed for other salivary (cortisol and testosterone/cortisol ratio), blood (lactate and Creatine Kinase), performance (peak power output) or perceptual (recovery or soreness) markers (all trial x treatment interactions: P>0.05); all of which were influenced by exercise (time effects: all P<0.05). A single session of WBC performed within 20 min of repeated sprint exercise elevated testosterone concentrations for 24 h but did not affect any other performance, physiological or perceptual measurements taken. While unclear, WBC may be efficacious for professional soccer players during congested fixture periods

Risk factors for depression in trauma-exposed children and adolescents: a systematic review and meta-analysis

Background: While Post Traumatic Stress Disorder (PTSD) has been the most frequently studied sequela in the aftermath of trauma, post-traumatic depression is at least as prevalent, if not more so. The impacts of depression are wide-ranging, deleterious and potentially long-term. Understanding the risk factors for post-traumatic depression in children and adolescents is therefore critical. The present systematic review and meta-analysis considered this question. Method: Three databases (Medline, PsycINFO, and Published International Literature on Traumatic Stress [PILOTS]) were searched for pertinent studies. Results: Fifty-seven studies (N = 45,981) allowed for the derivation of pooled effect sizes for 12 risk factors, contributing 145 effect sizes. All effect sizes were statistically significant. Negligible to small effect sizes were largely found for pre-trauma variables (age [r=0.09], gender [r=0.16], low family income [r=0.16] and prior trauma exposure [r=0.16) and trauma-related risk factors (trauma severity [r=0.20], peri‑traumatic distress [r=0.24] and direct exposure [r=0.07]). Small to large effect sizes were found for post-trauma variables (comorbid PTSD symptoms [r=0.58], avoidant coping [r=0.26], low social support [r=0.29] and maternal depression [r=0.20]) and bereavement (r=0.29). Limitations: Risk factor effect size estimates were characterised by significant heterogeneity, and several effect sizes were based on only a few studies (e.g. income, maternal depression). Conclusions: These findings suggest that the post-traumatic responses and environments of children and adolescents may be prominent risk factors for the emergence or maintenance of post-traumatic depression in children and adolescents. This highlights potential targets for assessment and monitoring those most at risk and may also inform treatment

Information needs of ethnically diverse, vaccine-hesitant parents during decision-making about the HPV vaccine for their adolescent child:a qualitative study

BackgroundThe English schools-based human papillomavirus (HPV) vaccination programme has the potential to eliminate HPV-related cancers if high uptake is achieved. However, unmet information needs among some parents may contribute to persisting lower uptake among minority ethnic groups. Through this study we aimed to understand the information needs of vaccine-hesitant, ethnically diverse parents during decision-making about the HPV vaccine for their adolescent child, to inform the future development of tailored communication materials.MethodsRecruitment was facilitated thorough healthcare and community organisations within London and the South West of England. Semi-structured interviews took place between April and August 2023. Thematic analysis was undertaken, assisted by NVivo software.ResultsOf the 29 parents interviewed, the majority were mothers (79%), belonged to a minority ethnic group (88%), and had an adolescent child unvaccinated against HPV (72%). Five of the interviews were undertaken in the participants’ primary language with translation support. Most parents interviewed had limited knowledge about the HPV vaccine and appeared conflicted as to whether vaccines could offer benefits to health. Misunderstanding around the potential of developing serious side-effects (e.g. fertility issues, developing cancer) were factors that could negatively impact decision-making by parents. Stigma associated with the sexual transmissibility of HPV did not always negatively impact decision-making. However, some parents chose not to vaccinate on the basis of perceptions of low risk and a preference to provide education about sexual behaviours to their adolescent child.ConclusionsTailoring communication materials to address misunderstandings could support informed decision-making by vaccine hesitant parents for their adolescent children to be vaccinated against HPV. Future communication materials about the HPV vaccine should highlight the benefits of protection against cancer to increase parents’ motivation for protect their adolescent child; provide accurate convincing information in relation to the excellent safety profile; and emphasise the importance of providing HPV vaccine at the recommended age, all alongside communicating the universality and commonality of HPV infection