Generalised action-angle coordinates defined on island chains

Straight-field-line coordinates are very useful for representing magnetic fields in toroidally confined plasmas, but fundamental problems arise regarding their definition in 3-D geometries because of the formation of islands and chaotic field regions, ie non-integrability. In Hamiltonian dynamical systems terms these coordinates are a form of action-angle variables, which are normally defined only for integrable systems. In order to describe 3-D magnetic field systems, a generalisation of this concept was proposed recently by the present authors that unified the concepts of ghost surfaces and quadratic-flux-minimising (QFMin) surfaces. This was based on a simple canonical transformation generated by a change of variable $\theta = \theta(\Theta,\zeta)$, where $\theta$ and $\zeta$ are poloidal and toroidal angles, respectively, with $\Theta$ a new poloidal angle chosen to give pseudo-orbits that are a) straight when plotted in the $\zeta,\Theta$ plane and b) QFMin pseudo-orbits in the transformed coordinate. These two requirements ensure that the pseudo-orbits are also c) ghost pseudo-orbits. In the present paper, it is demonstrated that these requirements do not \emph{uniquely} specify the transformation owing to a relabelling symmetry. A variational method of solution that removes this lack of uniqueness is proposed.Comment: 10 pages. Accepted by Plasma Physics and Controlled Fusion as part of a cluster of refereed papers in a special issue containing papers arising from the Joint International Stellarator & Heliotron Workshop and Asia-Pacific Plasma Theory Conference, held in Canberra and Murramarang Resort, Australia, 30 January - 3 February, 201

Implementing a Pre-Exposure Prophylaxis Intervention for Safer Conception among HIV Serodiscordant Couples: Recommendations for Health Care Providers

Couples in HIV serodiscordant relationships frequently desire children. Although partners who are virally suppressed pose almost no risk of transmitting HIV to their partners, partners who are inconsistently on therapy may transmit HIV to their partners when attempting to conceive. Pre-exposure prophylaxis (PrEP) is an available safer conception strategy for these couples but is not consistently offered. We sought to better understand barriers to PrEP implementation for couples seeking conception and patient perceptions on what providers could do to encourage use. We conducted in-depth, qualitative interviews with 11 participants representing six couples taking PrEP for safer conception in a safety-net hospital in New England. Semi-structured qualitative interviews assessed the following: Relationship nature and contextual factors; attitudes and perceptions regarding PrEP for safer conception; experience within health care systems related to HIV and PrEP; and facilitators, barriers, and other experiences using PrEP for safer conception. Four key themes have important implications for implementation of PrEP for safer conception: Knowledge and understanding gaps regarding HIV and PrEP among both members of the couple, role of insurance and financing in decision-making, learning to manage and adhere to a treatment plan, and the need for providers to enhance knowledge and offer further support. Addressing barriers to safer conception strategies at multiple levels is needed to prevent HIV transmission within serodiscordant couples who desire children. Providers can play an important role in lowering these barriers through the use of multiple strategies

High field magneto-transport in high mobility gated InSb/InAlSb quantum well heterostructures

We present high field magneto-transport data from a range of 30nm wide InSb/InAlSb quantum wells. The low temperature carrier mobility of the samples studied ranged from 18.4 to 39.5 m2V-1s-1 with carrier densities between 1.5x1015 and 3.28x1015 m-2. Room temperature mobilities are reported in excess of 6 m2V-1s-1. It is found that the Landau level broadening decreases with carrier density and beating patterns are observed in the magnetoresistance with non-zero node amplitudes in samples with the narrowest broadening despite the presence of a large g-factor. The beating is attributed to Rashba splitting phenomenon and Rashba coupling parameters are extracted from the difference in spin populations for a range of samples and gate biases. The influence of Landau level broadening and spin-dependent scattering rates on the observation of beating in the Shubnikov-de Haas oscillations is investigated by simulations of the magnetoconductance. Data with non-zero beat node amplitudes are accompanied by asymmetric peaks in the Fourier transform, which are successfully reproduced by introducing a spin-dependent broadening in the simulations. It is found that the low-energy (majority) spin up state suffers more scattering than the high-energy (minority) spin down state and that the absence of beating patterns in the majority of (lower density) samples can be attributed to the same effect when the magnitude of the level broadening is large

Enhancing Online or Blended Learning Environments with Active Learning

Active learning is more than just a trending buzzword. This paper explores engaging strategies that are evidence-based instructional practices. With a little creativity and technology, these strategies can easily be implemented in any online or blended learning environment to engage learners and increase student learning outcomes

Detection and mapping of hydrothermally altered rocks in the vicinity of the comstock lode, Virginia Range, Nevada, using enhanced LANDSAT images

The author has identified the following significant results. LANDSAT images enhanced by the band-ratioing method can be used for reconnaissance alteration mapping in moderately heavily vegetated semiarid terrain as well as in sparsely vegetated to semiarid terrain where the technique was originally developed. Significant vegetation cover in a scene, however, requires the use of MSS ratios 4/5, 4/6, and 6/7 rather than 4/5, 5/6, and 6/7, and requires careful interpretation of the results. Supplemental information suitable to vegetation identification and cover estimates, such as standard LANDSAT false-color composites and low altitude aerial photographs of selected areas is desirable

Patterns and correlates of active commuting in adults with type 2 diabetes: cross-sectional evidence from UK Biobank.

OBJECTIVES: To describe the active commuting (AC) patterns of adults with type 2 diabetes and how these relate to physical activity and sedentary behaviour in UK Biobank. Social and environmental correlates of AC will also be explored. DESIGN: Cross-sectional analysis of a cohort study. SETTINGS: This is a population cohort of over 500 000 people recruited from 22 centres across the UK. Participants aged between 37 and 73 years were recruited between 2006 and 2010. PARTICIPANTS: 6896 participants with a self-reported type 2 diabetes diagnosis who reported commuting to work and had complete covariate data were included in the analysis. EXPOSURE MEASURES: Exposure measures were AC to work, measured as usual mode of transport. OUTCOME MEASURES: Outcome measures were weekly minutes of moderate to vigorous physical activity (MVPA), hours/day of sedentary time and participation in active travel. RESULTS: AC (reporting walking or cycling to work only) was reported by 5.5% of participants, with the great majority using the car to commute (80%). AC was associated with an additional 73 (95% CI 10.8 to 134.9) and 105 (95% CI 41.7 to 167.2) weekly minutes of MVPA for men and women, respectively. AC was associated with reduced sedentary time (β -1.1, 95% CI -1.6 to -0.7 hours/day for men; and β -0.8, 95% CI -1.2 to -0.3 hours/day for women). Deprivation and distance from home to work were identified as correlates of AC behaviour. CONCLUSIONS: Rates of AC are very low in adults with type 2 diabetes. However, AC offers a potentially sustainable solution to increasing physical activity and reducing sedentary behaviour. Therefore, strategies to improve the environment and encourage AC may help to increase population levels of physical activity and reduce the disease burden associated with type 2 diabetes

Electrocardiographic safety evaluation of dihydroartemisinin piperaquine in the treatment of uncomplicated falciparum malaria.

Dihydroartemisinin-piperaquine (DP) could become a leading fixed combination malaria treatment worldwide. Although there is accumulating evidence of efficacy and safety from clinical trials, data on cardiotoxicity are limited. In two randomized controlled trials in Thailand, 56 patients had ECGs performed before treatment, 4 hours after the first dose, and 4 hours after the last dose. The mean (95% CI) changes in QTc interval (Bazett's correction) were 2 (-6 to 9) ms and 14 (7 to 21) ms, respectively. These small changes on the third day of treatment are similar to those observed elsewhere in the convalescent phase following antimalarial treatment with drugs known to have no cardiac effects and are therefore likely to result from recovery from acute malaria and not the treatment given. At therapeutic doses, DP does not have clinically significant effects on the electrocardiogram

Disability income support design and mental illness: a summary of the grey literature

Aim: Mental illnesses have many distinctive features such as their fluctuating nature, invisibility and lack of diagnostic clarity that make determining eligibility for disability income support challenging. How do policy-makers deal with these features when designing disability income support? More specifically, ‘How do mental illnesses come to be considered eligible disabilities?’, ‘What tools are used to assess mental illness for eligibility?’, ‘What challenges exist in this process?’ and ‘What approaches are used to address these challenges?’ We aimed to determine what evidence is available to policy-makers in Australia and Ontario (Canada) to answer these questions. Methods: Ten electronic databases and grey literature in both jurisdictions were searched using key words including disability income support, disability pension, mental illness, mental disability, addiction, depression and schizophrenia for articles published between 1991 and June 2013 yielding 1,341 articles of which 20 met the inclusion criteria and were critically appraised. Results: Results revealed that there is limited evidence available on disability income support design and mental illness in the Australian and Ontarian setting. Most of the evidence available is from the grey literature and draws on evidence from case law. Many documents reviewed argued that current policy in Australia and Ontario is frequently based on negative assumptions about mental illnesses rather than available evidence (either peer-reviewed or grey literature). Results showed that problems related to mental illness are largely related to the interpretation of the definition rather than the definition itself. Conclusions: The review confirmed that mental illnesses present many challenges when designing disability income support and that academic as well as grey literature, especially case law, provide insight into these challenges. More research is needed on addressing these challenges identified, particularly in these contexts, with the intention that more evidence on this topic could lead to policies for those with mental illness that are well-informed and do not reinforce societal prejudices

Cell Cycle Deregulation in Ewing's Sarcoma Pathogenesis

Ewing's sarcoma is a highly aggressive pediatric tumor of bone that usually contains the characteristic chromosomal translocation t(11;22)(q24;q12). This translocation encodes the oncogenic fusion protein EWS/FLI, which acts as an aberrant transcription factor to deregulate target genes necessary for oncogenesis. One key feature of oncogenic transformation is dysregulation of cell cycle control. It is therefore likely that EWS/FLI and other cooperating mutations in Ewing's sarcoma modulate the cell cycle to facilitate tumorigenesis. This paper will summarize current published data associated with deregulation of the cell cycle in Ewing's sarcoma and highlight important questions that remain to be answered