Modelling binary alloy solidification with adaptive mesh refinement

The solidification of a binary alloy results in the formation of a porous mushy layer, within which spontaneous localisation of fluid flow can lead to the emergence of features over a range of spatial scales. We describe a finite volume method for simulating binary alloy solidification in two dimensions with local mesh refinement in space and time. The coupled heat, solute, and mass transport is described using an enthalpy method with flow described by a Darcy-Brinkman equation for flow across porous and liquid regions. The resulting equations are solved on a hierarchy of block-structured adaptive grids. A projection method is used to compute the fluid velocity, whilst the viscous and nonlinear diffusive terms are calculated using a semi-implicit scheme. A series of synchronization steps ensure that the scheme is flux-conservative and correct for errors that arise at the boundaries between different levels of refinement. We also develop a corresponding method using Darcy's law for flow in a porous medium/narrow Hele-Shaw cell. We demonstrate the accuracy and efficiency of our method using established benchmarks for solidification without flow and convection in a fixed porous medium, along with convergence tests for the fully coupled code. Finally, we demonstrate the ability of our method to simulate transient mushy layer growth with narrow liquid channels which evolve over time

Development of a method to identify foot strike on an arena surface: application to jump landing

Foot strike can be difficult to determine using kinematics alone, particularly when studying equine activities on more compliant surfaces, so this study was done with the aim of developing and validating a method to determine foot strike on an arena surface that can be used in conjunction with kinematics alone, and of applying the method in the context of measuring foot strike during jump landing on an arena surface. A low-cost contact mat was developed. The timing of the contact mat switching ‘on’ was compared to the timing of a force platform onset of 20 N, load and loading rate at foot strike. Two groups of 25 participants were used in two separate studies to validate the contact mat: the first measured the difference in timing with respect to two different activities (running and stepping down from a box), and the second measured the difference in timing with respect to 1- and 2-cm depths of an arena surface during running. In a third study, the mat was used to measure leading limb foot strike of six horses during jump landing, and these data were compared to kinematics from a palmar marker on the hoof wall. All data were recorded at 500 Hz. A consistent difference in delay was found between the mat and force platform onset, and as a result, no significant differences (P>0.05) in timing delay between different loading rates or depths were found. During jump landing, foot strike (determined from the mat) occurred after the vertical velocity minima and the acceleration maxima for the hoof marker, but it occurred before the point where the rate of vertical displacement began to reduce. In conclusion, further work is needed to enhance these techniques, but these preliminary results indicate that this method may be effective in determining foot strike for field-based applications

G20 2014: reform of the international organisations, financial regulation, trade, accountability and anti-corruption

This issue of the G20 Monitor discusses the reform of international economic institutions, financial regulation, and the trade, accountability and anti-corruption agendas at the forthcoming Brisbane G20 Summit. It also provides a summary of the key ideas from the ‘G20 Conference: Strengthening Accountability and Effectiveness’ hosted by the Lowy Institute. Key findings: If the G20 is truly to be the world’s premier forum for international economic cooperation, fostering the reform of international economic institutions needs to be a fundamental objective. Ex ante regulatory impact assessments are an important tool for strengthening financial regulation and fostering financial stability globally. Trade, anti-corruption, and the accountability of the G20 are important agenda items for the forthcoming Brisbane Summit and go to the heart of the G20’s aim to boost growth and resilience

Demographic changes in UK rescue centre dog population between 2014 and 2018

Rescue centers remain a common means of rehoming a dog. There is a paucity of research into the composition of rescue center populations and its potential reflection of increased popularity of brachycephalic breeds. The study investigated changes in rescue center demographics from 2015 to 2018, compared to the wider dog population. Dogs on 16 rehoming centers’ websites were recorded weekly from June 2015 for 8 weeks and replicated from June 2018. Data were collected on 1793 dogs across the centers. Over 50% of which were classified as purebred in both years. Over 80% of the dogs were categorized into 24 breeds or breed crosses. Dogs categorized as brachycephalic increased from 24 (2.76%) in 2015 to 48 (5.19%) in 2018. Subadult dogs (3–4 years) were most prevalent in both years. While sex, breed type, and age of the rehoming center population has remained relatively stable, breeds are changing. Whilst low, brachycephalic numbers doubled in 3 years, mirroring their rising popularity within the UK, impacting on rehoming centers and prospective new owners with additional costs of brachycephalic obstructive airway syndrome surgery

VIDA: a virus database system for the organization of animal virus genome open reading frames

VIDA is a new virus database that organizes open reading frames (ORFs) from partial and complete genomic sequences from animal viruses. Currently VIDA includes all sequences from GenBank for Herpesviridae, Coronaviridae and Arteriviridae. The ORFs are organized into homologous protein families, which are identified on the basis of sequence similarity relationships, Conserved sequence regions of potential functional importance are identified and can be retrieved as sequence alignments. We use a controlled taxonomical and functional classification for all the proteins and protein families in the database. When available, protein structures that are related to the families have also been included. The database is available for online search and sequence information retrieval at http://www.biochem.ucl.ac.uk/bsm/virus-database/ VIDA.html

Adaptability among science teachers in schools: A multi-nation examination of its role in school outcomes

Adaptability helps teachers to navigate change, novelty, and uncertainty at work. We sought to extend understanding of adaptability by considering it at the school-level in 2189 high schools across eight nations. We investigated whether two job demands (disruptive student behavior, student diversity) and a job resource (teacher collaboration) are associated with school-average teacher adaptability. We also examined the association that school-average teacher adaptability has with teacher self-efficacy and, in turn, student self-efficacy. Findings showed, for example, that greater school-average teacher adaptability was positively associated with teacher self-efficacy and, in turn, student self-efficacy. Findings were similar across the eight nations

Simulation and Quality in Clinical Education

Abstract Background Simulation-based education (SBE) has become commonplace in healthcare education within hospitals, higher education institutions, the private healthcare sector, and private education providers. The standards and quality of delivery vary across the UK (1), leading to differing degrees of learning for healthcare professionals. This variance in standards makes research into the impact of SBE on the end user (the patient) difficult to measure. Review The delivery of SBE needs to be of a high standard if learning via this pedagogy is to be maximised and benefits to patients accurately assessed. This article aims to summarise the importance of quality within clinical SBE and how it can be achieved and maintained to produce a measurable impact on patient care. The current progress of the implementation of UK national standards for SBE is included to highlight the need for standardisation and guidance to support simulation centres and individuals to benchmark practice and work towards accreditation through quality measurement and monitoring processes. Suggestions are made on how such standards will affect the future of SBE and all those involved. Conclusion There is a clear need for the development of national standards for SBE delivery and for a stepped approach [i.e. minimum, intermediate, and advanced standards] depending on the size, capacity, and frequency of SBE education delivery. Considerable financial outlay will be required to monitor standards effectively. The enhanced use of current and future technologies should be considered with regards to monitoring standards as well as data collection for future research opportunities. Keywords Simulation, quality improvement, educational standard