5,001 research outputs found

    Computer program to determine pressure distributions and forces on blunt bodies of revolution

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    Program was written to include integration of surface pressure in order to obtain axial-force, normal-force, and pitching-moment coefficients. Program was written in CDC FORTRAN for the CDC-6600 computer system

    Public health information on COVID-19 for international travellers:Lessons learned from a mixed-method evaluation

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    Objectives: In the containment phase of the response to the COVID-19 outbreak, Public Health England (PHE) delivered advice to travellers arriving at major UK ports. We aimed to rapidly evaluate the impact and effectiveness of these communication materials for passengers in the early stages of the pandemic. Study design: The study design used is the mixed-methods evaluation. Methods: A questionnaire survey and follow-up interviews with passengers arriving at London Heathrow Airport on scheduled flights from China and Singapore. The survey assessed passengers’ knowledge of symptoms, actions to take, and attitudes towards PHE COVID-19 public health information; interviews explored their views of official public health information and self-isolation. Results: One hundred and twenty-one passengers participated in the survey and 15 in follow-up interviews. Eighty three percentage of surveyed passengers correctly identified all three COVID-19 associated symptoms listed in PHE information at that time. Most could identify the recommended actions and found the advice understandable and trustworthy. Interviews revealed that passengers shared concerns about the lack of wider official action, and that passengers’ knowledge had been acquired elsewhere as much from PHE. Respondents also noted their own agency in choosing to self-isolate, partially as a self-protective measure. Conclusion: PHE COVID-19 public health information was perceived as clear and acceptable, but we found that passengers acquired knowledge from various sources and they saw the provision of information alone on arrival as an insufficient official response. Our study provides fresh insights into the importance of taking greater account of diverse information sources and of the need for public assurance in creating public health information materials to address global health threats.</p

    The Globular Cluster M15. I. Identification, Discovery, and Period Determination of Variable Stars

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    We present new BVIBVI CCD photometry for variables in the globular cluster M15. Our photometry was obtained using both the image subtraction package ISIS and DAOPHOT/ALLFRAME. The data were acquired in 2001 on two observing runs on 11 observing nights using the 2-m telescope of the Bulgarian National Astronomical Observatory ``Rozhen'' with a Photometrics CCD camera. For 40 previously known variables, we present a period for the first time, and improved periods were obtained for many previously known variables. Fourteen new variables are reported. We present updated Bailey diagrams for the cluster and discuss its Oosterhoff classification. Although many of M15's RRab pulsators fall at an intermediate locus between Oosterhoff types I and II in the Bailey diagram, we argue that M15 is indeed a bona-fide Oosterhoff type IIComment: 48 pages, 7 figures, 3 table

    The unusually large population of Blazhko variables in the globular cluster NGC 5024 (M53)

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    We report the discovery of amplitude and phase modulations typical of the Blazhko effect in 22 RRc and 9 RRab type RR Lyrae stars in NGC 5024 (M53). This brings the confirmed Blazhko variables in this cluster to 23 RRc and 11 RRab, that represent 66% and 37% of the total population of RRc and RRab stars in the cluster respectively, making NGC 5024 the globular cluster with the largest presently known population of Blazhko RRc stars. We place a lower limit on the overall incidence rate of the Blazhko effect among the RR Lyrae population in this cluster of 52%. New data have allowed us to refine the pulsation periods. The limitations imposed by the time span and sampling of our data prevents reliable estimations of the modulation periods. The amplitudes of the modulations range between 0.02 and 0.39 mag. The RRab and RRc are neatly separated in the CMD, and the RRc Blazhko variables are on averge redder than their stable couterparts; these two facts may support the hypothesis that the HB evolution in this cluster is towards the red and that the Blazhko modulations in the RRc stars are connected with the pulsation mode switch.Comment: ACCEPTED IN MNRAS 14 pages, 9 figures and 6 table

    A dual process account of creative thinking

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    This article explicates the potential role played by type 1 thinking (automatic, fast) and type 2 thinking (effortful, logical) in creative thinking. The relevance of Evans's (2007) models of conflict of dual processes in thinking is discussed with regards to creative thinking. The role played by type 1 thinking and type 2 thinking during the different stages of creativity (problem finding and conceptualization, incubation, illumination, verification and dissemination) is discussed. It is proposed that although both types of thinking are active in creativity, the extent to which they are active and the nature of their contribution to creativity will vary between stages of the creative process. Directions for future research to test this proposal are outlined; differing methodologies and the investigation of different stages of creative thinking are discussed. Š Taylor & Francis Group, LLC

    Standard and generalized McDonald–Kreitman test: a website to detect selection by comparing different classes of DNA sites

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    The McDonald and Kreitman test (MKT) is one of the most powerful and extensively used tests to detect the signature of natural selection at the molecular level. Here, we present the standard and generalized MKT website, a novel website that allows performing MKTs not only for synonymous and nonsynonymous changes, as the test was initially described, but also for other classes of regions and/or several loci. The website has three different interfaces: (i) the standard MKT, where users can analyze several types of sites in a coding region, (ii) the advanced MKT, where users can compare two closely linked regions in the genome that can be either coding or noncoding, and (iii) the multi-locus MKT, where users can analyze many separate loci in a single multi-locus test. The website has already been used to show that selection efficiency is positively correlated with effective population size in the Drosophila genus and it has been applied to include estimates of selection in DPDB. This website is a timely resource, which will presumably be widely used by researchers in the field and will contribute to enlarge the catalogue of cases of adaptive evolution. It is available at http://mkt.uab.es

    Learning about COVID-19 across borders:public health information and adherence among international travellers to the UK

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    Objective: public health control measures at borders have long been central to national strategies for the prevention and containment of infectious diseases. Travel was inevitably associated with the rapid global transmission of COVID-19. In the UK, public health authorities tried to reduce the risks of travel-associated spread by providing public health information at ports of entry. This study investigates risk assessment processes, decision-making and adherence to official advice among international travellers, to provide evidence for future policy on the provision of public health information to facilitate safer international travel.Study design: this study is a qualitative study evaluation.Method: international air passengers arriving at the London Heathrow Airport on scheduled flights from China and Singapore were approached for interview after consenting to contact in completed surveys. Semi-structured interviews were conducted by telephone, using two topic guides to explore views of official public health information and self-isolation. Interview transcripts were coded and analysed thematically.Results: participants regarded official advice from Public Health England as adequate at the time, despite observing differences with intervention measures implemented in their countries of departure. Most participants also described adopting precautionary measures, including self-isolation and the use of face coverings that went beyond official advice, but reported adherence to guidance on contacting health authorities was more variable. Adherence to the official guidance was informed by the perceived salience of specific transmission possibilities and containment measures assessed in relation to participants’ local social and institutional environments.Conclusion: analysis of study findings demonstrates that international air travellers' responses to public health advice constitute a proactive process of risk assessment and rationalised decision-making to guide preventive action. This process incorporates consideration of the current living situation, trust in information sources, correspondence with cultural logics and willingness to accept potential risk to self and significant others. Our findings concerning international passengers’ understanding of, and compliance with, official advice and mitigation measures provide valuable evidence to inform future policy and generate recommendations on the presentation of public health information to facilitate safer international travel. Access to a central source of regularly updated official information would help minimise confusion between different national guidelines. Greater attention to the differentiated information needs of diverse groups in creating future public-facing guidance would help to minimise the uncertainties generated by the receipt of generic information

    Associations between the objectively-measured office environment and workplace step count and sitting time: cross-sectional analyses from the Active Buildings study

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    Office-based workers spend a large proportion of the day sitting and tend to have low overall activity levels. Despite some evidence that features of the external physical environment are associated with physical activity, little is known about the influence of the spatial layout of the internal environment on movement and the majority of data use self-report. This study investigated associations between objectively-measured sitting time and activity levels and the spatial layout of office floors in a sample of UK office-based workers. Participants wore activPAL accelerometers for at least three consecutive workdays. Primary outcomes were steps and proportion of sitting time per working hour. Primary exposures were office spatial layout, which was objectively-measured by deriving key spatial variables: ‘distance from each workstation to key office destinations’, ‘distance from participant’s workstation to all other workstations’, ‘visibility of co-workers’ and workstation ‘closeness’. 131 participants from 10 organisations were included. 54% were female, 81% were white, and the majority had a managerial or professional role (72%) in their organisation. The average proportion of the working hour spent sitting was 0.7 (SD 0.15); participants took on average 444 (SD 210) steps per working hour. Models adjusted for confounders revealed significant negative associations between step count and distance from each workstation to all other office destinations (e.g. B=-4.66, 95%CI: -8.12, -1.12, p<0.01) and nearest office destinations (e.g. B=-6.45, 95%CI: -11.88, -0.41, p<0.05) and visibility of workstations when standing (B=-2.35, 95%CI: -3.53, -1.18, p<0.001). The magnitude of these associations was small. There were no associations between spatial variables and sitting time per work hour. Contrary to our hypothesis, the further participants were from office destinations the less they walked, suggesting that changing the relative distance between workstations and other destinations on the same floor may not be the most fruitful target for promoting walking and reducing sitting in the workplace. However, reported effect sizes were very small and based on cross-sectional analyses. The approaches developed in this study could be applied to other office buildings to establish whether a specific office typology may yield more promising results

    Exogenous double-stranded RNA inhibits the infection physiology of rust fungi to reduce symptoms in planta

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    Rust fungi (Pucciniales) are a diverse group of plant pathogens in natural and agricultural systems. They pose ongoing threats to the diversity of native flora and cause annual crop yield losses. Agricultural rusts are predominantly managed with fungicides and breeding for resistance, but new control strategies are needed on non-agricultural plants and in fragile ecosystems. RNA interference (RNAi) induced by exogenous double-stranded RNA (dsRNA) has promise as a sustainable approach for managing plant-pathogenic fungi, including rust fungi. We investigated the mechanisms and impact of exogenous dsRNA on rust fungi through in vitro and whole-plant assays using two species as models, Austropuccinia psidii (the cause of myrtle rust) and Coleosporium plumeriae (the cause of frangipani rust). In vitro, dsRNA either associates externally or is internalized by urediniospores during the early stages of germination. The impact of dsRNA on rust infection architecture was examined on artificial leaf surfaces. dsRNA targeting predicted essential genes significantly reduced germination and inhibited development of infection structures, namely appressoria and penetration pegs. Exogenous dsRNA sprayed onto 1-year-old trees significantly reduced myrtle rust symptoms. Furthermore, we used comparative genomics to assess the wide-scale amenability of dsRNA to control rust fungi. We sequenced genomes of six species of rust fungi, including three new families (Araucariomyceaceae, Phragmidiaceae, and Skierkaceae) and identified key genes of the RNAi pathway across 15 species in eight families of Pucciniales. Together, these findings indicate that dsRNA targeting essential genes has potential for broad-use management of rust fungi across natural and agricultural systems

    Precision Prediction for the Big-Bang Abundance of Primordial Helium

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    Within the standard models of particle physics and cosmology we have calculated the big-bang prediction for the primordial abundance of \he to a theoretical uncertainty of less than 0.1 \pct (δYP<±0.0002)(\delta Y_P < \pm 0.0002), improving the current theoretical precision by a factor of 10. At this accuracy the uncertainty in the abundance is dominated by the experimental uncertainty in the neutron mean lifetime, τn=885.4±2.0sec\tau_n = 885.4 \pm 2.0 sec. The following physical effects were included in the calculation: the zero and finite-temperature radiative, Coulomb and finite-nucleon-mass corrections to the weak rates; order-α\alpha quantum-electrodynamic correction to the plasma density, electron mass, and neutrino temperature; and incomplete neutrino decoupling. New results for the finite-temperature radiative correction and the QED plasma correction were used. In addition, we wrote a new and independent nucleosynthesis code designed to control numerical errors to be less than 0.1\pct. Our predictions for the \EL[4]{He} abundance are presented in the form of an accurate fitting formula. Summarizing our work in one number, YP(η=5×10−10)=0.2462±0.0004(expt)±<0.0002(theory) Y_P(\eta = 5\times 10^{-10}) = 0.2462 \pm 0.0004 (expt) \pm < 0.0002 (theory). Further, the baryon density inferred from the Burles-Tytler determination of the primordial D abundance, ΩBh2=0.019±0.001\Omega_B h^2 = 0.019\pm 0.001, leads to the prediction: YP=0.2464±0.0005(D/H)±<0.0002(theory)±0.0005(expt)Y_P = 0.2464 \pm 0.0005 (D/H) \pm < 0.0002 (theory) \pm 0.0005 (expt). This ``prediction'' and an accurate measurement of the primeval \he abundance will allow an important consistency test of primordial nucleosynthesis.Comment: Replaced fitting formulas - new versions differ by small but significant amount. Other minor changes. 30 pages, 17 figures, 5 table
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