2,801 research outputs found

    Peculiar Velocity and Deaberration of the Sky

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    Recent studies have found the earth's peculiar velocity to be significant in microwave background based tests for compact cosmic topology, and modifications to these tests have been proposed. Tests of non-gaussianity, weak lensing analysis and new tests using improved CMB data will also be sensitive to peculiar velocity. We propose here to simplify matters by showing how to construct a deaberrated CMB map to which any test requiring a Hubble flow viewpoint can be applied without further complication. In a similar manner deaberration can also be applied to object surveys used for example in topological searches and matter distribution analysis. In particular we have produced a revised list of objects with z > 1.0 using the NASA/IPAC Extragalactic Database.Comment: 8 pages, 1 figure, v4 accepted by Ap

    Spitzer Space Telescope spectral observations of AGB stars in the Fornax dwarf spheroidal galaxy

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    We have observed five carbon-rich AGB stars in the Fornax dwarf spheroidal (dSph) galaxy, using the Infrared Spectrometer on board the Spitzer Space Telescope. The stars were selected from a near-infrared survey of Fornax and include the three reddest stars, with presumably the highest mass-loss rates, in that galaxy. Such carbon stars probably belong to the intermediate-age population (2-8 Gyr old and metallicity of [Fe/H] -1) of Fornax. The primary aim of this paper is to investigate mass-loss rate, as a function of luminosity and metallicity, by comparing AGB stars in several galaxies with different metallicities. The spectra of three stars are fitted with a radiative transfer model. We find that mass-loss rates of these three stars are 4-7x10^-6 Msun yr-1. The other two stars have mass-loss rates below 1.3x10^-6 Msun yr-1. We find no evidence that these rates depend on metallicity, although we do suggest that the gas-to-dust ratio could be higher than at solar metallicity, in the range 240 to 800. The C2H2 bands are stronger at lower metallicity because of the higher C/O ratio. In contrast, the SiC fraction is reduced at low metallicity, due to low silicon abundance. The total mass-loss rate from all known carbon-rich AGB stars into the interstellar medium of this galaxy is of the order of 2x10^-5 Msun yr-1. This is much lower than that of the dwarf irregular galaxy WLM, which has a similar visual luminosity and metallicity. The difference is attributed to the younger stellar population of WLM. The suppressed gas-return rate to the ISM accentuates the difference between the relatively gas-rich dwarf irregular and the gas-poor dwarf spheroidal galaxies. Our study will be useful to constrain gas and dust recycling processes in low metallicity galaxies.Comment: MNRAS accepte

    Communicating future overheating risks to building design practitioners:Using the Low Carbon Futures tool

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    The Low Carbon Futures tool provides a probabilistic assessment of future overheating risks and cooling demands for domestic and nondomestic buildings in the UK. The approach adopted for the development of the Low Carbon Futures tool includes academic rigour within the development of the calculation engine, and also practitioner feedback throughout the process. This paper discusses the journey of the tool from modelling and simulation to the practitioner engagement, which took place by means of a questionnaire, focus groups and interviews with building design professionals aimed at understanding how the issue of overheating in buildings is being addressed. Throughout these events, the synergies between designing for low-carbon targets and designing for a future climate were explored. A final dissemination event was held to identify output styles that could be generated by the Low Carbon Futures tool that would be more practical and useful for specific client types. The workshop discussions serve to shape the outputs from the tool, and the feedback gathered will be used to inform a number of output styles, based on client type. Practical application: This paper outlines the development of the Low Carbon Futures tool for analysing overheating risks in buildings and discusses the practitioner feedback obtained from industry professionals on the use and applicability of the tool, in a final event hosted by the Low Carbon Futures research team in London. This event confirmed that practitioners need to be comfortable with the layout and format of the output in order to communicate its meaning and possible implications to a range of clients. A balanced output is required, which conveys some of the complexity of the underlying analysis, but which is easily understood and conveyed to a potentially lay audience. </jats:p

    Development of an Objective Structured Clinical Examination as a Component of Assessment for Initial Board Certification in Anesthesiology.

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    With its first administration of an Objective Structured Clinical Examination (OSCE) in 2018, the American Board of Anesthesiology (ABA) became the first US medical specialty certifying board to incorporate this type of assessment into its high-stakes certification examination system. The fundamental rationale for the ABA's introduction of the OSCE is to include an assessment that allows candidates for board certification to demonstrate what they actually "do" in domains relevant to clinical practice. Inherent in this rationale is that the OSCE will capture competencies not well assessed in the current written and oral examinations-competencies that will allow the ABA to judge whether a candidate meets the standards expected for board certification more properly. This special article describes the ABA's journey from initial conceptualization through first administration of the OSCE, including the format of the OSCE, the process for scenario development, the standardized patient program that supports OSCE administration, examiner training, scoring, and future assessment of reliability, validity, and impact of the OSCE. This information will be beneficial to both those involved in the initial certification process, such as residency graduate candidates and program directors, and others contemplating the use of high-stakes summative OSCE assessments

    {BOAO Photometric Survey of Galactic Open Clusters. II. Physical Parameters of 12 Open Clusters

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    We have initiated a long-term project, the BOAO photometric survey of open clusters, to enlarge our understanding of galactic structure using UBVI CCD photometry of open clusters which have been little studied before. This is the second paper of the project in which we present the photometry of 12 open clusters. We have determined the cluster parameters by fitting the Padova isochrones to the color-magnitude diagrams of the clusters. All the clusters except for Be 0 and NGC 1348 are found to be intermediate-age to old (0.2 - 4.0 Gyrs) open clusters with a mean metallicity of [Fe/H] = 0.0.Comment: 11 page

    Cost-Effectiveness of Skin Surveillance Through a Specialized Clinic for Patients at High Risk of Melanoma

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    Purpose Clinical guidelines recommend that people at high risk of melanoma receive regular surveillance to improve survival through early detection. A specialized High Risk Clinic in Sydney, Australia was found to be effective for this purpose; however, wider implementation of this clinical service requires evidence of cost-effectiveness and data addressing potential overtreatment of suspicious skin lesions. Patients and Methods A decision-analytic model was built to compare the costs and benefits of specialized surveillance compared with standard care over a 10-year period, from a health system perspective. A high-risk standard care cohort was obtained using linked population data, comprising the Sax Institute’s 45 and Up cohort study, linked to Medicare Benefits Schedule claims data, the cancer registry, and hospital admissions data. Benefits were measured in quality-adjusted life-years gained. Sensitivity analyses were undertaken for all model parameters. Results Specialized surveillance through the High Risk Clinic was both less expensive and more effective than standard care. The mean saving was A6,828(956,828 (95% CI, 5,564 to $8,092) per patient, and the mean quality-adjusted life-year gain was 0.31 (95% CI, 0.27 to 0.35). The main drivers of the differences were detection of melanoma at an earlier stage resulting in less extensive treatment and a lower annual mean excision rate for suspicious lesions in specialized surveillance (0.81; 95% CI, 0.72 to 0.91) compared with standard care (2.55; 95% CI, 2.34 to 2.76). The results were robust when tested in sensitivity analyses. Conclusion Specialized surveillance was a cost-effective strategy for the management of individuals at high risk of melanoma. There were also fewer invasive procedures in specialized surveillance compared with standard care in the community
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