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Cascade photoelectrocatalysis (PEC) is a possible method to improve the selectivity of solar-driven CO2 reduction (CO2R). This concept can be realized by coupling different CO2R catalysts to different subcells in a multijunction photovoltaic (PV) stack. Efficient implementation will require careful tuning of the photocurrents and design of the photovoltages provided by the subcells to the CO2R catalysts in such a way as to facilitate the target reaction. Here, we outline the design principles of the tandem PEC approach using two-step conversion of CO2 to ethylene in aqueous electrolyte, via a CO intermediate, as a model system. To perform this reaction, the first coupled PV-catalyst component should provide 4 electrons to reduce 2 molecules of CO2 to CO; the second component should provide 8 electrons to reduce 2 CO molecules to C2H4. Based on known CO2R catalysts, the overpotential required to produce CO can be less than that required to reduce it to ethylene, creating the opportunity for improved efficiency. Cascade PEC can be realized in a three-terminal tandem (3TT) configuration using III-V-semiconductor based subcells coupled to Au (produces CO intermediate) and Cu (converts CO to ethylene). The current to each catalyst can be controlled by the area of the subcell exposed to the electrolyte, and the photovoltage is determined by the materials selected and device configuration. Operating conditions are found by simulating the coupled system using the open-source circuit simulator SPICE (Simulation Program with Integrated Circuits Emphasis). We identify conditions under which a 3TT configuration can have a higher solar to chemical conversion efficiency compared to a two-terminal two-junction tandem (2T 2J) with the same absorbers and a Cu catalyst only. We also show that 3TT PEC devices can be less sensitive to variations in catalyst activity compared to 2T devices. Finally, we discuss the applications of cascade PEC to CO2 reduction, using different intermediates, and to other chemical networks.

Learning Together is a whole-school intervention, evaluated using a randomized controlled trial in southeast England, which reduced bullying and improved physical and mental health. This paper examines trial data using fuzzy-set qualitative comparative analysis to test hypotheses derived from embedded qualitative research about potential causal pathways. Analyses suggested that the intervention worked via three mechanisms: improving student commitment to school; improving student pro-social skills; and de-escalating conflict and bullying. Evidence also suggests that these mechanisms may have been activated via other resources in schools not receiving Learning Together resources. The analysis suggests which contextual features may be important for activating these mechanisms.

Background The need to engage boys in gender-transformative relationships and sexuality education (RSE) to reduce adolescent pregnancy is endorsed by the World Health Organization and the United Nations Educational, Scientific and Cultural Organization. Objectives To evaluate the effects of If I Were Jack on the avoidance of unprotected sex and other sexual health outcomes. Design A cluster randomised trial, incorporating health economics and process evaluations. Setting Sixty-six schools across the four nations of the UK. Participants Students aged 13–14 years. Intervention A school-based, teacher-delivered, gender-transformative RSE intervention (If I Were Jack) versus standard RSE. Main outcome measures Self-reported avoidance of unprotected sex (sexual abstinence or reliable contraceptive use at last sex) after 12–14 months. Secondary outcomes included knowledge, attitudes, skills, intentions and sexual behaviours. Results The analysis population comprised 6556 students: 86.6% of students in the intervention group avoided unprotected sex, compared with 86.4% in the control group {adjusted odds ratio 0.85 [95% confidence interval (CI) 0.58 to 1.26], p = 0.42}. An exploratory post hoc analysis showed no difference for sexual abstinence [78.30% intervention group vs. 78.25% control group; adjusted odds ratio 0.85 (95% CI 0.58 to 1.24), p = 0.39], but more intervention group students than control group students used reliable contraception at last sex [39.62% vs. 26.36%; adjusted odds ratio 0.52 (95% CI 0.29 to 0.920), p = 0.025]. Students in schools allocated to receive the intervention had significantly higher scores on knowledge [adjusted mean difference 0.18 (95% CI 0.024 to 0.34), p = 0.02], gender-equitable attitudes and intentions to avoid unintended pregnancy [adjusted mean difference 0.61 (95% CI 0.16 to 1.07), p = 0.01] than students in schools allocated to receive the control. There were positive but non-significant differences in sexual self-efficacy and communication skills. The total mean incremental cost of the intervention compared with standard RSE was £2.83 (95% CI –£2.64 to £8.29) per student. Over a 20-year time horizon, the intervention is likely to be cost-effective owing to its impact on unprotected sex because it would result in 379 (95% CI 231 to 477) fewer unintended pregnancies, 680 (95% CI 189 to 1467) fewer sexually transmitted infections and a gain of 10 (95% CI 5 to 16) quality-adjusted life-years per 100,000 students for a cost saving of £9.89 (95% CI –£15.60 to –£3.83). Limitations The trial is underpowered to detect some effects because four schools withdrew and the intraclass correlation coefficient (0.12) was larger than that in sample size calculation (0.01). Conclusions We present, to our knowledge, the first evidence from a randomised trial that a school-based, male engagement gender-transformative RSE intervention, although not effective in increasing avoidance of unprotected sex (defined as sexual abstinence or use of reliable contraception at last sex) among all students, did increase the use of reliable contraception at last sex among students who were, or became, sexually active by 12–14 months after the intervention. The trial demonstrated that engaging all adolescents early through RSE is important so that, as they become sexually active, rates of unprotected sex are reduced, and that doing so is likely to be cost-effective. Future work Future studies should consider the longer-term effects of gender-transformative RSE as students become sexually active. Gender-transformative RSE could be adapted to address broader sexual health and other settings. Trial registration This trial is registered as ISRCTN10751359. Funding This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (PHR 15/181/01) and will be published in full in Public Health Research; Vol. 11, No. 8. See the NIHR Journals Library website for further project information. Plain language summary Adolescent pregnancy is often thought to be an issue for young women alone, but it is important to engage young men to tackle the problem and find solutions. The If I Were Jack intervention was especially designed to engage with boys as well as girls aged 14 years and to promote positive masculinity and gender equality to prevent adolescent pregnancy and promote positive sexual health. It uses tailored interactive films and resources, made with the help of students and teachers, to make it relevant to each of the four UK nations. This relationship and sexuality education intervention encourages adolescents to avoid unprotected sex by delaying sexual activity until they feel ready and to use reliable contraception once sexually active. It also promotes knowledge, attitudes (such as beliefs about gender and masculinities), skills and intentions for safe and pleasurable relationships. In this trial, we compared students in 33 schools randomly allocated to deliver the intervention with students in 33 schools that continued with their usual relationship and sexuality education practices. Four schools withdrew, two because of COVID-19 school closures. This left a total of 6556 students who completed questionnaires at the start of the study and 12–14 months later. Responses from all these students showed that If I Were Jack had a positive impact on knowledge, attitudes and intentions required for safe and pleasurable relationships, but did not have a significant effect on overall avoidance of unprotected sex. This was because the intervention had no effect on delaying sexual activity. However, we found that the intervention was effective in increasing the use of reliable contraception as students became sexually active, as well as for those who already were sexually active prior to receiving the intervention. We also found that If I Were Jack was likely to provide value for money by reducing unintended pregnancies and improving sexual health. Scientific summary Background The need for relationship and sexuality education (RSE) to especially engage with young men and boys to promote positive sexual health for all, and to be gender transformative to challenge the gender inequalities that underlie young women’s generally poorer sexual health outcomes (especially in relation to sexual violence, adolescent pregnancy and sexually transmitted infections), is widely endorsed by the World Health Organization and the United Nations Educational, Scientific and Cultural Organization, among others. Objectives The JACK trial evaluated the effectiveness and cost-effectiveness of the If I Were Jack intervention, a schools-based RSE intervention, which is designed to especially engage young men as well as young women and promote joint responsibility in preventing adolescent pregnancy by avoiding unprotected sex and in promoting positive sexual health and relationships. We assessed whether there would be higher rates of self-reported avoidance of unprotected sex (either by remaining sexually abstinent or by using a reliable form of contraception) among students in schools allocated to use If I Were Jack than among those in schools that continued with their usual RSE. Design We undertook a multicentre, parallel-group cluster randomised trial of the If I Were Jack intervention with schools as the unit of randomisation. We incorporated a health economic cost–consequences analysis and process evaluation. Setting The trial was conducted in secondary-level schools across the four nations of the UK. Recruitment We sampled schools from Department of Education-listed secondary schools in each nation of the UK (Northern Ireland, Wales, Scotland and England), with consideration of the socioeconomic status of schools [based on the proportion of students eligible for free school meals (FSM) as indicated by the School Meal Census]. In each nation, eligible schools were stratified into two levels according to FSM eligibility rates (schools above and below the median national percentage of FSM for all eligible schools). Independent private, special, and Irish/Welsh-medium and Scottish Gaelic schools and schools with

The outdoor operation of electrochemical solar fuels devices must contend with challenges presented by the cycles of solar irradiance, temperature, and other meteorological factors. Herein, we discuss challenges associated with these fluctuations presented over three timescales, including the effects of diurnal cycling over the course of many days, a single diurnal cycle over the course of hours, and meteorological phenomena that cause fluctuations on the order of seconds to minutes. We also highlight both reaction-independent and reaction-specific effects of variable conditions for the hydrogen evolution reaction and CO2 reduction reaction. We identify key areas of research for advancing the outdoor operation of solar fuels technology and highlight the need for metrics and benchmarks to enable the comparison of diurnal studies across systems and geographical locations. [ABSTRACT FROM AUTHOR]

There is a strong research base on the underlying concomitants of early developing math skills. Fewer studies have focused on later developing skills. Here, we focused on direct and indirect contributions of cognitive measures (e.g., language, spatial skills, working memory) and numerosity measures, as well as arithmetic proficiency, on key outcomes of fraction performance, proportional reasoning, and broad mathematics achievement at sixth grade (N = 162) via path analysis. We expected a hierarchy of skill development, with predominantly indirect effects of cognitive factors via number and arithmetic. Results controlling for age showed that the combination of cognitive, number, and arithmetic variables cumulatively accounted for 38% to 44% of the variance in fractions, proportional reasoning, and broad mathematics. There was consistency across outcomes, with more proximal skills providing direct effects and with the effects of cognitive skills being mediated by number and by more proximal skills. Results support a hierarchical progression from domain-general cognitive processes through numerosity and arithmetic skills to proportional reasoning to broad mathematics achievement. [This article was published in "Journal of Experimental Child Psychology," v145 p95-119 May 2016.]

Education policy increasingly promotes action groups as a key strategy for student and/or staff participation in school improvement and whole-school health promotion. Such groups can coordinate multi-component interventions, increase participation and engagement, and enable local adaptations, but few process evaluations have assessed this. We evaluated fidelity, feasibility and acceptability of action groups as part of a trial of a whole-school intervention to reduce bullying and aggression and promote health in English secondary schools, which reported multiple health and educational impacts. Action groups involved students and staff, supported by external facilitators, and drew on data on student needs. They aimed to: coordinate implementation of restorative practices and a social and emotional competencies curriculum; review policies and rules; and enact local decisions to modify school environments. Our process evaluation used interviews, focus groups, observations and questionnaires to assess action groups' fidelity, role in coordination, role in local adaptation, support from external facilitators and data on student needs, and acceptability in engaging members. Fidelity was high in the first two years but lower in the third year when external facilitators withdrew. Student needs data were perceived as useful, but views on external facilitators were mixed. Groups successfully reviewed policies and rules, planned activities and coordinated restorative practices, but were less successful in implementing the curriculum. Success was facilitated by the involvement of school leaders. Members reported high satisfaction and empowerment. Action groups are a promising strategy for leading whole-school health promotion. Implementation is supported by external facilitation, local data and involvement of senior managers.