The Design of Reinforced Concrete Buildings to Resist Earthquake Forces

There does not exist to today, and perhaps there never will be, any known method of predicting the location and time at which an earthquake will occur. Neither can we predict the maximum intensity that earthquakes in any given locality will bring. Hence the practicing structural engineer is constantly faced with the problem of deciding how much , if any seismic force to include when designing any particular structure , and from the economic viewpoint, how often will this force occur. At present, he will of course be guided by the particular building code of the area in which he is working but these codes, because of the lack of any conclusive information based in research or experience, are likely to skip over the subject very lightly or to omit it altogether

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

Organisational interventions for improving wellbeing and reducing work-related stress in teachers [Review].

Background: The teaching profession is an occupation with a high prevalence of work-related stress. This may lead to sustained physical and mental health problems in teachers. It can also negatively affect the health, wellbeing and educational attainment of children, and impose a financial burden on the public budget in terms of teacher turnover and sickness absence. Most evaluated interventions for the wellbeing of teachers are directed at the individual level, and so do not tackle the causes of stress in the workplace. Organisational-level interventions are a potential avenue in this regard. Objectives: To evaluate the effectiveness of organisational interventions for improving wellbeing and reducing work-related stress in teachers. Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, ASSIA, AEI, BEI, BiblioMap, DARE, DER, ERIC, IBSS, SSCI, Sociological Abstracts, a number of specialist occupational health databases, and a number of trial registers and grey literature sources from the inception of each database until January 2015. Selection criteria: Randomised controlled trials (RCTs), cluster-RCTs, and controlled before-and-after studies of organisational-level interventions for the wellbeing of teachers. Data collection and analysis: We used standard methodological procedures expected by Cochrane. Main results: Four studies met the inclusion criteria. They were three cluster-randomised controlled trials and one with a stepped-wedge design. Changing task characteristics One study with 961 teachers in eight schools compared a task-based organisational change intervention along with stress management training to no intervention. It found a small reduction at 12 months in 10 out of 14 of the subscales in the Occupational Stress Inventory, with a mean difference (MD) varying from -3.84 to 0.13, and a small increase in the Work Ability Index (MD 2.27; 95% confidence interval (CI) 1.64 to 2.90; 708 participants, low-quality evidence). Changing organisational characteristics@ Two studies compared teacher training combined with school-wide coaching support to no intervention. One study with 59 teachers in 43 schools found no significant effects on job-related anxiety (MD -0.25 95% CI -0.61 to 0.11, very low-quality evidence) or depression (MD -0.26 95% CI -0.57 to 0.05, very low-quality evidence) after 24 months. The other study with 77 teachers in 18 schools found no significant effects on the Maslach Burnout Inventory subscales (e.g. emotional exhaustion subscale: MD -0.05 95% CI -0.52 to 0.42, low-quality evidence) or the Teacher Perceived Emotional Ability subscales (e.g. regulating emotions subscale: MD 0.11 95% CI -0.11 to 0.33, low-quality evidence) after six months. Multi-component intervention: One study with 1102 teachers in 34 schools compared a multi-component intervention containing performance bonus, job promotion opportunities and mentoring support to a matched-comparison group consisting of 300 schools. It found moderately higher teacher retention rates (MD 11.50 95% CI 3.25 to 19.75 at 36 months follow-up, very low-quality evidence). However, the authors reported results only from one cohort out of four (eight schools), demonstrating a high risk of reporting bias. Authors’ conclusions: We found low-quality evidence that organisational interventions lead to improvements in teacher wellbeing and retention rates. We need further evaluation of the effects of organisational interventions for teacher wellbeing. These studies should follow a complex- interventions framework, use a cluster-rando

Climate change, maternal health and birth outcomes: how does environmental heat affect pregnancy and birth outcomes in The Gambia?

Extreme heat exposure is linked to poor maternal and child health. With anthropogenic climate change, global annual temperatures have risen to 1.2°C above pre-industrial levels and are predicted to reach around 2.7°C by the end of the century. West Africa is high-risk for the impacts of climate change, including extreme heat, both in terms of exposure, health risks and adaptation options. This thesis explores the impact of extreme heat on maternal and fetal physiology to improve understanding of the pathophysiological pathways and examines the longer-term impacts of heat on growth in the first 1000 days of life. Firstly, a prospective cohort study was conducted of heat stress, heat strain and fetal strain in pregnant subsistence farmers in West Kiang, The Gambia. Additionally qualitative work explored the lived experiences of pregnant subsistence farmers, to include how working in the heat whilst pregnant feels, what adaptation options are available, and their concerns for the future. Secondly, an analysis of robust data from a randomized controlled trial of nutritional supplementation characterizes the relationship between chronic heat exposure and growth faltering in the first 1000 days of life, also in West Kiang, The Gambia. Thirdly, I engaged schools across The Gambia to identify climate or environmental issues in their areas, develop solutions to these local problems and brought everyone together for a festival to share climate change solutions. The findings showed a worrying level of heat exposure already being experienced. Acute impacts on maternal and fetal physiology were high. Long term impacts of heat on growth faltering were significant for weight-for-age and weight-for-height z-scores. This thesis highlights the ongoing risk to maternal and child health of rising global temperatures, but also demonstrates strong youth and community drive to alter the current trajectory

Student- and school-level belonging and commitment and student smoking, drinking and misbehaviour

Objectives: It has been suggested that students are healthier in schools where more students are committed to school. Previous research has examined this only using a proxy measure of value-added education (a measure of whether school-level attendance and attainment are higher than predicted by students’ social profile), finding associations with smoking tobacco, use of alcohol and illicit drugs, and violence. These findings do not provide direct insights into the associations between school-level aggregate student commitment and health behaviours, and may simply reflect the proxy measure being residually confounded by unmeasured student characteristics. We examined the previously used proxy measure of value-added education, as well as direct measures at the level of the school and the student of lack of student commitment to school to see whether these were associated with students’ self-reported smoking tobacco, alcohol use and school misbehaviour. Design: Cross-sectional survey. Setting: A total of 40 schools in south-east England. Methods: Multi-level analyses. Results: There were associations between school- and student-level measures of lack of commitment to school and tobacco smoking, alcohol use and school misbehaviour outcomes, but the proxy measure of school-level commitment, value-added education, was not associated with these outcomes. A sensitivity analysis focused only on violent aspects of school misbehaviour found a pattern of associations identical to that found for the measure of misbehaviour. Conclusion: Our study provides the first direct evidence in support of the Theory of Human Functioning and School Organisation

Coupling of groundwater, river level and rainfall in an upland floodplain

Upland floodplains provide an important function in regulating river flows and controlling the coupling of hillslope runoff with rivers. To investigate the responses of floodplain groundwater to river flows and rainfall events, a small floodplain in an upland area of the River Tweed catchment, Scotland, was characterised using geophysics, 3D geological mapping and hydrogeological testing; and monitoring undertaken from September 2011 to February 2013 of: groundwater levels in five pairs of piezometers; river stage and flow at the upstream and downstream limits of the study site; soil moisture on the adjacent hillslope; and meteorological parameters. Periodical groundwater chemistry and residence data were also collected. The floodplain aquifer is permeable throughout but partially stratified, comprising dominantly alluvial and glaciofluvial sandy gravels between 8 and 15m interspersed with thin, intermittent layers of low permeability silts, clays and peats. Overlying the gravel aquifer is a partial thin cover of low permeability alluvial silts, and it is underlain dominantly by low permeability glaciolacustrine silts and clays. High permeability solifluction deposits mantle much of the adjacent hillslope and provide a rapid connection to the floodplain aquifer. The unusually wet year of 2012 provides a good example of how a temperate upland floodplain responds to consistently high rainfall. Statistical analysis and graphical interpretation of groundwater level, rainfall, soil moisture and river stage demonstrates that: 1) dominant groundwater flow within the floodplain is in the same direction as the river, from up-valley to down-valley; 2) soil moisture in the hillslope is strongly correlated with local rainfall, but groundwater across much of the floodplain is more strongly influenced by river stage; except 3) groundwater near the edge of floodplain, which responds more slowly to local rainfall and river stage changes ; and 4) subsurface flow from the hillslope to the floodplain occurs during high rainfall events. A detailed investigation of three flood events, when the river rose above bank level and flooded adjacent fields and groundwater became artesian in parts of the floodplain, suggests that antecedent moisture conditions can partly explain the differences in groundwater response during different flood events, where high intensity or long duration rainfall can cause saturated soil conditions, reducing soil water storage capacity and hence promoting flood conditions. A conceptual model based on field data of groundwater flow after storm events during antecedent unsaturated and saturated soil conditions is presented

'We've Got Some Underground Business Selling Junk Food': Qualitative Evidence of the Unintended Effects of English School Food Policies

Drawing on two qualitative studies, we report evidence of pervasive black markets in confectionery, ‘junk’ food and energy drinks in English secondary schools. Data were collected at six schools through focus groups and interviews with students (n= 149) and staff (n= 36), and direct observations. Supermarkets, new technologies and teachers’ narrow focus on attainment have enabled these ‘underground businesses’ to emerge following increased state regulation of school food and drink provision. These activities represent a new form of counter-school resistance to institutional constraints within the context of enduring, although less visible, class-based stratification in British secondary schools. These black markets also appear to be partly driven by the unsafe and unsociable nature of school canteens, which was a recurring theme across all schools. These findings highlight how new school food ‘bans’ ignore the complex, ecological drivers of poor diet in youth and the potential for iatrogenic effects which exacerbate health inequalities

Absence of magnetic-proximity effect at the interface of Bi2_2Se3_3 and (Bi,Sb)2_2Te3_3 with EuS

We performed x-ray magnetic circular dichroism (XMCD) measurements on heterostructures comprising topological insulators (TIs) of the (Bi,Sb)$_2$(Se,Te)$_3$ family and the magnetic insulator EuS. XMCD measurements allow us to investigate element-selective magnetic proximity effects at the very TI/EuS interface. A systematic analysis reveals that there is neither significant induced magnetism within the TI nor an enhancement of the Eu magnetic moment at such interface. The induced magnetic moments in Bi, Sb, Te, and Se sites are lower than the estimated detection limit of the XMCD measurements of $\sim\!10^{-3}$ $\mu_\mathrm{B}$/at.Comment: 7 pages, 3 figures, published in Physical Review Letter