Effect of contact wire gradient on the dynamic performance of the catenary pantograph system

This paper considers the interaction between a train mounted pantograph and a railway overhead line, presenting results that could be used to reduce the cost of installing overhead electrification, for example, by reducing the need for expensive bridge reconstruction. Ideally, overhead wires would run at a constant height parallel to the track, however, gradients are often unavoidable due to clearance limitations requiring lower wire heights at bridges and tunnels, and higher heights above level crossings. In this study, the influence of a range of contact wire gradients on the contact force between the overhead line and pantograph has been studied using a validated finite element model. Introducing a windowing technique to identify discrete dynamic behaviours found that overhead wire gradients can be increased with minimal effect on the contact force, showing current wire gradient limits are conservative. This may open up opportunities for electrification, less disruptive than following current standards

Abrogated cryptic activation of lentiviral transfer vectors

Despite significant improvements in lentivirus (LV) vector-based gene therapy there are still several safety risks using LV vectors including the potential formation of replication-competent LV particles. To address this shortcoming, we constructed a novel and safer gene transfer system using modified SIN-based LV gene transfer vectors. Central to our approach is a conditional deletion of the Ψ packaging signal after integration in the target genome. Here we demonstrate that after transduction of target cells, conventional SIN-based LV transfer vectors can still be mobilized. However mobilization is rendered undetectable if transductions are followed by a Cre/loxP-mediated excision of Ψ. Thus conditional elimination of the packaging signal may represent another advance in increasing the safety of LV vectors for gene therapeutic treatment of chronic diseases

Affordances and limitations of electronic storybooks for young children's emergent literacy

AbstractStories presented on phones, tablets and e-readers now offer an alternative to print books. The fundamental challenge has become to specify when and for whom the manner in which children retain information from stories has been changed by electronic storybooks, for better and for worse. We review the effects of digitized presentations of narratives that include oral text as well as multimedia information sources (e.g., animations and other visual and sound effects, background music, hotspots, games, dictionaries) on children's emergent literacy. Research on preschool and kindergarten children has revealed both positive and negative effects of electronic stories conditional upon whether materials are consistent with the way that the human information processing system works. Adding certain information to electronic storybooks can facilitate multimedia learning, especially in children at-risk for language or reading difficulty. Animated pictures, sometimes enriched with music and sound, that match the simultaneously presented story text, can help integrate nonverbal information and language and thus promote storage of those in memory. On the other hand, stories enhanced with hypermedia interactive features like games and “hotspots” may lead to poor performance on tests of vocabulary and story comprehension. Using those features necessitates task switching, and like multitasking in general, seems to cause cognitive overload. However, in accordance with differential susceptibility theory, well-designed technology-enhanced books may be particularly suited to improve learning conditions for vulnerable children and turn putative risk groups into successful learners. This new line of research may have far-reaching consequences for the use of technology-enhanced materials in education

Is impartiality enough? Government impartiality and citizens' perceptions of public service quality

10.1111/gove.12527Governance343727-76

Public Sector Innovation in the Asia Pacific - Trends, Challenges, and Opportunities

10.1111/1467-8500.12435Australian Journal of Public Administration379271 - 27