Students’ responses to theory: An FD case study

This paper will report on a small qualitative case study which explored the professional formation of students on a work-based learning course. These students were studying part-time to become professionally qualified youth workers and were already working or volunteering in the field. Drawing on interviews with students and their employers nine months after completion of the WBL course we will map some of the ways in which they consider participation has influenced their understanding of the field and their approach to their work. Contrary to expectations, our own and those in the professional literature, we found that students placed considerable value on the contribution of theory. In some cases this had led to significant changes in perspective, leading them to question their own practices and those of colleagues. While some had encountered resistance others had the autonomy to change their practices during and after the course

Few smooth d-polytopes with n lattice points

We prove that, for fixed n there exist only finitely many embeddings of Q-factorial toric varieties X into P^n that are induced by a complete linear system. The proof is based on a combinatorial result that for fixed nonnegative integers d and n, there are only finitely many smooth d-polytopes with n lattice points. We also enumerate all smooth 3-polytopes with at most 12 lattice points. In fact, it is sufficient to bound the singularities and the number of lattice points on edges to prove finiteness.Comment: 20+2 pages; major revision: new author, new structure, new result

Assessing health and well-being among older people in rural South Africa

Background: The population in developing countries is ageing, which is likely to increase the burden of noncommunicable diseases and disability. Objective: To describe factors associated with self-reported health, disability and quality of life (QoL) of older people in the rural northeast of South Africa. Design: Cross-sectional survey of 6,206 individuals aged 50 and over. We used multivariate analysis to examine relationships between demographic variables and measures of self-reported health (Health Status), functional ability (WHODASi) and quality of life (WHOQoL). Results: About 4,085 of 6,206 people eligible (65.8%) completed the interview. Women (Odds Ratio (OR) 1.30, 95% CI 1.09, 1.55), older age (OR2.59, 95% CI 1.97, 3.40), lower education (OR1.62, 95% CI 1.31,2.00), single status (OR1.18, 95% CI 1.01, 1.37) and not working at present (OR1.29, 95% CI 1.06, 1.59) were associated with a low health status. Women were also more likely to report a higher level of disability (OR1.38, 95% CI 1.14, 1.66), as were older people (OR2.92, 95% CI 2.25, 3.78), those with no education (OR1.57, 95% CI 1.26, 1.97), with single status (OR1.25, 95% CI 1.06, 1.46) and not working at present (OR1.33, 95% CI 1.06, 1.66). Older age (OR1.35, 95% CI 1.06, 1.74), no education (OR1.39, 95% CI 1.11, 1.73), single status (OR1.28, 95% CI 1.10, 1.49), a low household asset score (OR1.52, 95% CI 1.19, 1.94) and not working at present (OR1.32; 95% CI 1.07, 1.64) were all associated with lower quality of life. Conclusions: This study presents the first population-based data from South Africa on health status, functional ability and quality of life among older people. Health and social services will need to be restructured to provide effective care for older people living in rural South Africa with impaired functionality and other health problems

Skyrmion Hall Effect Revealed by Direct Time-Resolved X-Ray Microscopy

Magnetic skyrmions are highly promising candidates for future spintronic applications such as skyrmion racetrack memories and logic devices. They exhibit exotic and complex dynamics governed by topology and are less influenced by defects, such as edge roughness, than conventionally used domain walls. In particular, their finite topological charge leads to a predicted "skyrmion Hall effect", in which current-driven skyrmions acquire a transverse velocity component analogous to charged particles in the conventional Hall effect. Here, we present nanoscale pump-probe imaging that for the first time reveals the real-time dynamics of skyrmions driven by current-induced spin orbit torque (SOT). We find that skyrmions move at a well-defined angle {\Theta}_{SH} that can exceed 30{\deg} with respect to the current flow, but in contrast to theoretical expectations, {\Theta}_{SH} increases linearly with velocity up to at least 100 m/s. We explain our observation based on internal mode excitations in combination with a field-like SOT, showing that one must go beyond the usual rigid skyrmion description to unravel the dynamics.Comment: pdf document arxiv_v1.1. 24 pages (incl. 9 figures and supplementary information

Effect of Adhesive Stiffness and CFRP Geometry on the Behavior of Externally Bonded CFRP Retrofit Measures Subject to Monotonic Loads

Nine 10" (254 mm) deep, 6" (152 mm) wide and 186" (4730 mm) long concrete beams having three #4 longitudinal steel reinforcing bars as primary flexural reinforcement, were tested monotonically to failure under mid-point bending. Eight beams were strengthened with various arrangements of soffit-mounted externally bonded carbon fiber reinforced polymer (CFRP) and one beam was left as an unretrofit control specimen. A commercially available 4" (102 mm) wide, 0.055" (1.4 mm) thick preformed unidirectional high strength carbon fiber (CFRP) strip system was used in this study. Additionally, two commercially available adhesives, with significantly different moduli, were used to apply the CFRP strips to the concrete substrate. In order to investigate the effect of the CFRP strip width-to-soffit width ratio (bf/b), four different strip arrangements were used. All specimens tested in this program exhibited intermediate crack induced debonding behavior. The observed failures were generally bond-induced although concrete crushing was also observed in all cases. Increased flexural capacity and decreased flexural ductility was observed with increasing CFRP retrofit material area. Observations indicate retrofit geometry has an influence on the overall retrofit performance. The FRP width-to-substrate width ratio (bf/b) is shown to affect intermediate crack induced debonding behavior - an increase in strain at debonding is seen for specimens having a smaller bf/b ratio. Additionally, superior performance in the form of higher general yield and maximum loads, and higher deflections at these loads, was observed for the specimens having the lower modulus of elasticity adhesive. The current American Concrete Institute (ACI) recommendation intended to mitigate debonding failure by limiting the allowable strain in the FRP (the limiting strain is referred to as åfub) is shown to be non-conservative, overestimating the strain where debonding becomes likely by two fold for the high modulus adhesive and less so for the low modulus adhesive. The equation for estimating åfub recommended by Teng et al. (2001), including the modifying kb term, appears to provide appropriately conservative estimates of debonding for the specimens having low modulus adhesive although remains unconservative for the high modulus adhesive. This indicates that the nature of the adhesive should be included in the calculation of limiting strain. Proposed values for the coefficient kb which accounts for the bf/b ratio were found to generally underestimate the effect of the width ratio for the test specimens. Therefore, not only is the ratio bf/b (as represented by kb) a contributing factor to bond behavior, its contribution may be underestimated. Cover delamination (end peel debonding) was effectively mitigated in all specimens by extending the CFRP close to the support along the relatively long shear span

Valuation of Child Behavioral Problems from the Perspective of US Adults

To assess preferences between child behavioral problems and estimate their value on a quality-adjusted life year (QALYs) scale

Using collaborative hackathons to coproduce knowledge on local climate adaptation governance

While coproduction of knowledge is growing in popularity in social sciences, and especially climate change research, we still need to better understand how to coproduce climate knowledge. In this paper, we explore how collaborative climate hackathons coproduce local adaptation knowledge, and what this method reveals about local climate governance. The data derives from two collaborative climate hackathons, called Klimathons, that attracted 73 and 98 participants in Bergen, Norway. The participants were practitioners and decision-makers from local, regional, and national institutions as well as researchers from natural and social climate sciences. The collaborative group work revolved around the challenges and solutions of local adaptation planning and uncovered how a diversity of key actors understand the local adaptation work in Norway. These interventions revealed that there are significant disagreements and divergent understanding of relevant laws, regulations and responsibility between practitioners working within the same governance system. Though the cross-sectorial interaction does not dissolve these divergences, they allow actors to renegotiate boundaries between divergent knowledge communities. The Klimathons helped us navigate the complexity of local climate adaptation by shifting the focus to how different actors make sense of and work on adaptation and showing the intertwining and interdependence of potential drivers for adaptation.publishedVersio

Comparison of dense optical flow and PIV techniques for mapping surface current flow in tidal stream energy sites

AbstractMarine renewable energy site and resource characterisation, in particular tidal stream energy, require detailed flow measurements which often rely on high-cost in situ instrumentation which is limited in spatial extent. We hypothesise uncrewed aerial vehicles (UAV) offer a low-cost and low-risk data collection method for tidal stream environments, as recently techniques have been developed to derive flow from optical videography. This may benefit tidal and floating renewable energy developments, providing additional insight into flow conditions and complement traditional instrumentation. Benefits to existing data collection methods include capturing flow over a large spatial extent synchronously, which could be used to analyse flow around structures or for site characterisation; however, uncertainty and method application to tidal energy sites is unclear. Here, two algorithms are tested: large-scale particle image velocimetry using PIVlab and dense optical flow. The methods are applied on video data collected at two tidal stream energy sites (Pentland Firth, Scotland, and Ramsey Sound, Wales) for a range of flow and environmental conditions. Although average validation measures were similar (~ 20–30% error), we recommend PIVlab processed velocity data at tidal energy sites because we find bias (underprediction) in optical flow for higher velocities (&gt; 1 m/s).</jats:p

The Value Adults Place On Child Health And Functional Status

By summarizing the value adults place on child health and functional status, this study provides a new quantitative tool that enhances our understanding of the benefits of new health technologies and illustrates the potential contributions of existing datasets for comparative effectiveness research in pediatrics