Spin precession and spin Hall effect in monolayer graphene/Pt nanostructures

Spin Hall effects have surged as promising phenomena for spin logics operations without ferromagnets. However, the magnitude of the detected electric signals at room temperature in metallic systems has been so far underwhelming. Here, we demonstrate a two-order of magnitude enhancement of the signal in monolayer graphene/Pt devices when compared to their fully metallic counterparts. The enhancement stems in part from efficient spin injection and the large resistivity of graphene but we also observe 100% spin absorption in Pt and find an unusually large effective spin Hall angle of up to 0.15. The large spin-to-charge conversion allows us to characterise spin precession in graphene under the presence of a magnetic field. Furthermore, by developing an analytical model based on the 1D diffusive spin-transport, we demonstrate that the effective spin-relaxation time in graphene can be accurately determined using the (inverse) spin Hall effect as a means of detection. This is a necessary step to gather full understanding of the consequences of spin absorption in spin Hall devices, which is known to suppress effective spin lifetimes in both metallic and graphene systems.Comment: 14 pages, 6 figures. Accepted in 2D Materials. https://doi.org/10.1088/2053-1583/aa882

Understanding the development of minimum unit pricing of alcohol in Scotland: A qualitative study of the policy process

Background: Minimum unit pricing of alcohol is a novel public health policy with the potential to improve population health and reduce health inequalities. Theories of the policy process may help to understand the development of policy innovation and in turn identify lessons for future public health research and practice. This study aims to explain minimum unit pricing’s development by taking a ‘multiple-lenses’ approach to understanding the policy process. In particular, we apply three perspectives of the policy process (Kingdon’s multiple streams, Punctuated-Equilibrium Theory, Multi-Level Governance) to understand how and why minimum unit pricing has developed in Scotland and describe implications for efforts to develop evidence-informed policymaking. Methods: Semi-structured interviews were conducted with policy actors (politicians, civil servants, academics, advocates, industry representatives) involved in the development of MUP (n = 36). Interviewees were asked about the policy process and the role of evidence in policy development. Data from two other sources (a review of policy documents and an analysis of evidence submission documents to the Scottish Parliament) were used for triangulation. Findings: The three perspectives provide complementary understandings of the policy process. Evidence has played an important role in presenting the policy issue of alcohol as a problem requiring action. Scotland-specific data and a change in the policy ‘image’ to a population-based problem contributed to making alcohol-related harms a priority for action. The limited powers of Scottish Government help explain the type of price intervention pursued while distinct aspects of the Scottish political climate favoured the pursuit of price-based interventions. Conclusions: Evidence has played a crucial but complex role in the development of an innovative policy. Utilising different political science theories helps explain different aspects of the policy process, with Multi-Level Governance particularly useful for highlighting important lessons for the future of public health policy

An exploratory review of HIV prevention mass media campaigns targeting men who have sex with men.

BACKGROUND: Men who have sex with men (MSM) are at increased risk of HIV infection in both high- and low-income settings. Mass media campaigns have been used as a means of communicating HIV health promotion messages to large audiences of MSM. There is no consensus on which designs are most appropriate to evaluate the process and outcomes of such interventions. METHODS: An exploratory review was conducted to assess research examining awareness, acceptability, effects on HIV testing, disclosure and sexual risk, and cost-effectiveness of HIV mass media campaigns targeting MSM. We searched for quantitative and qualitative studies published between 1990 and May 2011 via the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Psych Info, ISI Web of Science, OpenGrey and COPAC, and contacting experts. No exclusions were made on the basis of study design or methods because our primary aim was to map evidence. We appraised study quality and present a narrative synthesis of findings. RESULTS: Sixteen reports from 12 studies were included. All were from high-income countries and most examined multi-media interventions. Half of the studies were single cross-sectional surveys. Three repeat cross-sectional studies collected data pre and post the campaign launch. The remaining three studies monitored routine data. Three studies included a nested qualitative component. Campaign coverage was the most commonly reported outcome (9 studies). Imagery, tone of language, content and relevance were identified in the qualitative research as factors influencing campaign acceptability. HIV testing rates (or intention to test) were reported by five studies. Two studies reported that testing rates were higher among men who had seen the campaigns compared to men who had not, but this may reflect confounding. Findings were less consistent regarding reductions in sexual risk behaviours (4 studies). None of the studies examined cost-effectiveness. CONCLUSIONS: Campaigns aim to provide MSM with information to help prevent transmission of HIV and to address increasing motivation and changing norms towards precautionary behaviours. However, the limitations of mass media in imparting skills in effecting behaviour change should be recognised, and campaigns supplemented by additional components may be better-suited to achieving these goals

Dilemmas of school-based Relationships and Sexuality Education for and about consent

In 2018, reflecting in this journal on the arrival of the ‘age of consent’ into sexuality education, Jen Gilbert questioned what would happen to a concept drawn in part from legal contexts, but partly also driven by the passion of feminist activists, when it met the demands and logics – the learning outcomes and lesson plans – of the classroom. This article offers one response, drawing on qualitative data from two whole-school sexual health programmes, Positive Choices and Project Respect, piloted in secondary schools in England between 2017 and 2019. It describes how each addressed the issue of consent and focuses on specific ‘moments’ that illuminate some of the challenges of doing so for both staff and students. Our analyses aim to contribute to the practice of relationships and sexuality education in schools by helping educators to anticipate, understand and therefore better address the dilemmas that teaching for and about consent might encounter. We argue that these dilemmas relate both to broader (and gendered) ideas of consent and entitlement, and to issues specific to schools. However, we also argue that a more theorised account of the school enables us to identify the minor achievements that are nonetheless possible

Natural flood management: does age of forest influence flood mitigation?

Forestry has the potential to alleviate flooding by delaying the downstream passage of flood flows, reducing the volume of runoff through interception (Calder et al. 2003) and promoting rainfall infiltration into the soil (Forest Research, 2010). However, it is difficult to predict how much a forest needs to grow, before there is any significant effect on soil properties to increase the capacity to 1) store water, 2) increase soil infiltration, 3) slow water and reduce water flow connectivity to rivers. The structural coupling between plant roots and soil environment determines flow paths through the soil, where root growth and die-back influences soil hydraulic properties, increasing macropore distribution (Bengough, 2012) and soil permeability. We test the hypothesis: as the forest grows soil permeability below forests will increase, due to increasing macropore structure

Development of soil hydraulic properties below grassland, ancient forest and plantation forests

Woodlands in particular have the potential to alleviate flooding by delaying the downstream passage of flood flows, reducing the volume of runoff through interception (Calder et al. 2003) and promoting rainfall infiltration into the soil (Thomas & Nisbet, 2006). The natural processes which occur below ground to enable a change in hydraulic pathways and storage are complex and are dependent not only on geology, but also on landuse. We focus this study on below-ground changes that influence soil water characteristics, such as soil hydraulic conductivity, soil water retention and soil structure, which are all important in understanding how the planting of trees can mitigate localised flooding

Is positive school climate and adolescent mental health: Longitudinal study of young people in England

Background and objectives: Studies suggest that individual student-reported connection to school is associated with better mental health. However, there is less evidence for associations between schools’ overall school climate and the mental health of their students. This may reflect limitations in which mental health outcomes have been examined. We conducted a large longitudinal study in schools, hypothesising that we would find associations at both the student and school levels between student-reported positive school climate, and reduced student conduct and emotional problems and improved mental wellbeing. // Methods: We tracked students in 20 English secondary schools from near the end of the first year of secondary school (age 11/12) over 3 years using reliable measures of school climate and mental health. // Results: We found associations between student-level reports of positive school climate at baseline, and reduced conduct and emotional problems and better mental wellbeing at 3-year follow-up adjusting for various potential confounders. We also found some evidence of adjusted associations between baseline school-level measures of overall positive climate and better student mental health at follow-up. However, these student- and school-level associations reduced considerably when also adjusting for baseline mental health. // Conclusions: Our findings suggest that there are associations between school climate and student mental health at both the student and school level but these associations are complex and not necessarily causal

Spin precession in anisotropic media

We generalize the diffusive model for spin injection and detection in nonlocal spin structures to account for spin precession under an applied magnetic field in an anisotropic medium, for which the spin lifetime is not unique and depends on the spin orientation.We demonstrate that the spin precession (Hanle) line shape is strongly dependent on the degree of anisotropy and on the orientation of the magnetic field. In particular, we show that the anisotropy of the spin lifetime can be extracted from the measured spin signal, after dephasing in an oblique magnetic field, by using an analytical formula with a single fitting parameter. Alternatively, after identifying the fingerprints associated with the anisotropy, we propose a simple scaling of the Hanle line shapes at specific magnetic field orientations that results in a universal curve only in the isotropic case. The deviation from the universal curve can be used as a complementary means of quantifying the anisotropy by direct comparison with the solution of our generalized model. Finally, we applied our model to graphene devices and find that the spin relaxation for graphene on silicon oxide is isotropic within our experimental resolution

Public understanding of COVID-19 antibody testing and test results: A qualitative study conducted in the U.K. early in the pandemic

Background: During the COVID-19 pandemic, antibody testing was proposed by several countries as a surveillance tool to monitor the spread of the virus and potentially to ease restrictions. In the UK, antibody testing originally formed the third pillar of the UK Government's COVID-19 testing programme and was thought to offer hope that those with a positive antibody test result could return to normal life. However, at that time scientists and the public had little understanding of the longevity of COVID-19 antibodies, and whether they provided immunity to reinfection or transmission of the virus. Objective: This paper explores the UK public's understanding of COVID-19 testing, perceived test accuracy, the meaning of a positive test result, willingness to adhere to restrictive measures in response to an antibody test result and how they expect other people to respond. Methods: On-line synchronous focus groups were conducted in April/May 2020 during the first wave of the pandemic and the most stringent period of the COVID-19 restrictive measures. Data were analysed thematically. Results: There was confusion in responses as to whether those with a positive or negative test should return to work and which restrictive measures would apply to them or their household members. Participants raised concerns about the wider public response to positive antibody test results and the adverse behavioural effects. There were worries that antibody tests could create a divided society particularly if those with a positive test result were given greater freedoms or chose to disregard the restrictive measures. Conclusion: Should these tests be offered more widely, information should be developed in consultation with the public to ensure clarity and address uncertainty about test results and subsequent behaviours

How Do Contextual Factors Influence Implementation and Receipt of Positive Youth Development Programs Addressing Substance Use and Violence? A Qualitative Meta-Synthesis of Process Evaluations

Objective:Positive youth development (PYD) often aims to prevent tobacco, alcohol, and drugs use and violence. We systematically reviewed PYD interventions, synthesizing process, and outcomes evidence. Synthesis of outcomes, published elsewhere, found no overall evidence of reducing substance use or violence but notable variability of fidelity. Our synthesis of process evaluations examined how implementation varied and was influenced by context.Data Source:Process evaluations of PYD aiming to reduce substance use and violence.Study Inclusion Criteria:Overall review published since 1985; written in English; focused on youth aged 11 to 18 years; focused on interventions addressing multiple positive assets; reported on theory, process, or outcomes; and concerned with reducing substance use or violence. Synthesis of process evaluations examined how implementation varies with or is influenced by context.Data Extraction:Two reviewers in parallel.Data Synthesis:Thematic synthesis.Results:We identified 12 reports. Community engagement enhanced program appeal. Collaboration with other agencies could broaden the activities offered. Calm but authoritative staff increased acceptability. Staff continuity underpinned diverse activities and durable relationships. Empowering participants were sometimes in tension with requiring them to engage in diverse activities.Conclusion:Our systematic review identified factors that might help improve the fidelity and acceptability of PYD interventions. Addressing these might enable PYD to fulfill its potential as a means of promoting health