653 research outputs found

    Further buffeting tests in a cryogenic wind tunnel

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    Further measurements of buffeting, using wing-root strain gauges, were made in the NASA Langley 0.3 m Cryogenic Wind Tunnel to refine techniques which will be used in larger cryogenic facilities such as the United States National Transonic Facility (NTF) and European Transonic Wind Tunnel (ETW). The questions addressed included the relative importance of variations in frequency parameter and Reynolds number, the choice of model material (considering both stiffness and damping) and the effects of static aeroelastic distortion. The main series of tests was made on half models of slender 65 deg delta wings with a sharp leading edge. The three delta wings had the same planform but widely different bending stiffness and frequencies (obtained by varying both the material and the thickness of the wings). It was known that the flow on this configuration would be insensitive to variations in Reynold number. Additional tests were made on one unswept half-wing of aspect ratio 1.5 with an NPL 9510 aerofoil section, known to be sensitive to variations in Reynolds number at transonic speeds. For brevity the test Mach numbers were restricted to M = 0.21 and 0.35 for the delta wings and to M = 0.30 for the unswept wing

    Fast nonadiabatic dynamics of many-body quantum systems

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    Modeling many-body quantum systems with strong interactions is one of the core challenges of modern physics. A range of methods has been developed to approach this task, each with its own idiosyncrasies, approximations, and realm of applicability. However, there remain many problems that are intractable for existing methods. In particular, many approaches face a huge computational barrier when modeling large numbers of coupled electrons and ions at finite temperature. Here, we address this shortfall with a new approach to modeling many-body quantum systems. On the basis of the Bohmian trajectory formalism, our new method treats the full particle dynamics with a considerable increase in computational speed. As a result, we are able to perform large-scale simulations of coupled electron-ion systems without using the adiabatic Born-Oppenheimer approximation

    Risk factors for active trachoma in The Gambia.

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    Trachoma has been endemic in The Gambia for decades but national surveys indicate that the prevalence is falling. Risk factor data can help guide trachoma control efforts. This study investigated risk factors for active trachoma and ocular Chlamydia trachomatis infection in children aged below 10 years in two Gambian regions. The overall prevalence of C. trachomatis infection was only 0.3% (3/950) compared with 10.4% (311/2990) for active trachoma, therefore analyses were only performed for active trachoma. After adjustment, increased risk of trachoma was associated with being aged 1-2 years (odds ratio (OR) 2.20, 95% CI 1.07-4.52) and 3-5 years (OR 3.62, 95% CI 1.80-7.25) compared with <1 year, nasal discharge (OR 2.07, 95% CI 1.53-2.81), ocular discharge (OR 2.68, 95% CI 1.76-4.09) and there being at least one other child in the household with active trachoma (OR 11.28, 95% CI 8.31-15.31). Compared with other occupations, children of traders had reduced risk (OR 0.53, 95% CI 0.30-0.94). At the household level, only the presence of another child in the household with active trachoma was associated with increased risk of active trachoma, suggesting that current trachoma control interventions are effective at this level. In contrast, child-level factors were associated with increased risk after adjustment, indicating a need to increase control efforts at the child level

    CADRE: the Central Aspergillus Data REpository 2012

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    The Central Aspergillus Data REpository (CADRE; http://www.cadre-genomes.org.uk) is a public resource for genomic data extracted from species of Aspergillus. It provides an array of online tools for searching and visualising features of this significant fungal genus. CADRE arose from a need within the medical community to understand the human pathogen Aspergillus fumigatus. Due to the paucity of Aspergillus genomic resources 10 years ago, the long-term goal of this project was to collate and maintain Aspergillus genomes as they became available. Since our first release in 2004, the resource has expanded to encompass annotated sequence for eight other Aspergilli and provides much needed support to the international Aspergillus research community. Recent developments, however, in sequencing technology are creating a vast amount of genomic data and, as a result, we shortly expect a tidal wave of Aspergillus data. In preparation for this, we have upgraded the database and software suite. This not only enables better management of more complex data sets, but also improves annotation by providing access to genome comparison data and the integration of high-throughput data

    Rapid Syphilis Tests as Catalysts for Health Systems Strengthening: A Case Study from Peru.

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    OBJECTIVES: Untreated maternal syphilis leads to adverse pregnancy outcomes. The use of point of care tests (POCT) offers an opportunity to improve screening coverage for syphilis and other aspects of health systems. Our objective is to present the experience of the introduction of POCT for syphilis in Peru and describe how new technology can catalyze health system strengthening. METHODS: The study was implemented from September 2009-November 2010 to assess the feasibility of the use of a POCT for syphilis for screening pregnant women in Lima, Peru. Outcomes measured included access to syphilis screening, treatment coverage, partner treatment, effect on patient flow and service efficiency, acceptability among providers and patients, and sustainability. RESULTS: Before the introduction of POCT, a pregnant woman needed 6 visits to the health center in 27 days before she received her syphilis result. We trained 604 health providers and implemented the POCT for syphilis as the "two for one strategy", offering with one finger stick both syphilis and HIV testing. Implementation of the POCT resulted in testing and treatment on the first visit. Screening and treatment coverages for syphilis improved significantly compared with the previous year. Implementation of POCT has been scaled up nationally since the study ended, and coverages for screening, treatment and partner treatment have remained over 92%. CONCLUSIONS: Implementation of POCT for syphilis proved feasible and acceptable, and led to improvement in several aspects of health services. For the process to be effective we highlight the importance of: (1) engaging the authorities; (2) dissipating tensions between providers and identifying champions; (3) training according to the needs; (4) providing monitoring, supervision, support and recognition; (5) sharing results and discussing actions together; (6) consulting and obtaining feedback from users; and (7) integrating with other services such as with rapid HIV testing

    Low risk management intervention? : Limited impact of remedial tillage on net ecosystem carbon balance at a commercial Miscanthus plantation

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    Acknowledgements The work was supported by Measurement and Analysis of bioenergy greenhouse gases (MAGLUE, EP/M013200/1). We were also supported by the Natural Environment Research Council award number NE/R016429/1 as part of the UK-SCAPE programme and the Ecosystem Land Use Modelling (ELUM) project which was commissioned and funded by the Energy Technologies Institute (www.elum.ac.uk). A.H. was additionally funded by the ADVENT project funded by the UK Natural Environment Research Council (NE/M019691/1) and ADVANCES funded by the UK Natural Environment Research Council (NE/M019691/1), EPSRC funded UKERC-4 and both A.H. and R.L.R were funded by BBSRC funded PCB4GGR project (BB/V011553/1). We would also like to thank theland owner for allowing access to their fields and the land owner and Terravesta Ltd for providing information on crop management.Peer reviewe

    Making sense of variety in place leadership: the case of England’s smart cities

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    Making sense of variety in place leadership: the case of England’s smart cities. Regional Studies. There is rising interest in cities becoming ‘smart’ knowledge-oriented economies by prioritizing more digitally enabled modes of production and service delivery. Whilst the prevalence of these new organizational forms is well understood, the way that leadership agency is exercised (i.e., the actors involved and their modalities of action) is not. Drawing on new empirical data and sense-making methodology, the paper reveals discursive patterns in how public agencies, private firms and communities ‘see’ and ‘do’ leadership within these place-based contexts, and concludes that success in exploiting the social and spatial dynamics of ‘smart’ development lies in understanding actors’ assumptions about commercial and social gain

    Individual leader to interdependent leadership: A case study in leadership development and tripartite evaluation

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    This article is available open access through the publisher’s website at the link below. Copyright @ 2013 Sage Publications.The Problem - In this case study we see a move away from orthodox views of school leadership as “headship” to a more contemporary model of educational leadership wherein we note a departure from functional, curricula-based school leadership toward more human resource development (HRD) approaches. The aim of this study was to consider the effectiveness of an educational development program for middle leaders within an educational establishment. The Solution - We examined the impact of a bespoke higher education leadership development intervention in Leadership (and Change) on the formation and cohesiveness of a newly formed innovative leadership structure. The Stakeholders - The leadership development intervention was designed through a tripartite collaboration including a university, senior school leaders, and staff. The intervention was designed to shift leadership from individual leader agency to interdependent human leadership agency. Through tripartite evaluation we uncover leadership development praxis that transcends the boundaries of conventional educational leadership and reemphasizes the benefits of bridging the academic/practitioner divide and the application of theory to praxis
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