2,628 research outputs found

    Looking Back on a Closing Chapter: The Experience of the East German Churches

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    Can Reflection from Grains Diagnose the Albedo?

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    By radiation transfer models with a realistic power spectra of the projected density distributions, we show that the optical properties of grains are poorly constrained by observations of reflection nebulae. The ISM is known to be hierarchically clumped from a variety of observations (molecules, H I, far-infrared). Our models assume the albedo and phase parameter of the dust, the radial optical depth of the sphere averaged over all directions, and random distributions of the dust within the sphere. The outputs are the stellar extinction, optical depth, and flux of scattered light as seen from various viewing angles. Observations provide the extinction and scattered flux from a particular direction. Hierarchical geometry has a large effect on the flux of scattered light emerging from a nebula for a particular extinction of the exciting star. There is a very large spread in both scattered fluxes and extinctions for any distribution of dust. Consequently, an observed stellar extinction and scattered flux can be fitted by a wide range of albedos. With hierarchical geometry it is not completely safe to determine even relative optical constants from multiwavelength observations of the same reflection nebula. The geometry effectively changes with wavelength as the opacity of the clumps varies. Limits on the implications of observing the same object in various wavelengths are discussed briefly. Henry (2002) uses a recipe to determine the scattered flux from a star with a given extinction. It is claimed to be independent of the geometry. It provides considerably more scattering than our models, probably leading to an underestimate of the grain albedos from the UV Diffuse Galactic Light.Comment: 27 pages, including 7 figures. Accepted by Ap

    Spitzer IRAC observations of newly-discovered planetary nebulae from the Macquarie-AAO-Strasbourg H-alpha Planetary Nebula Project

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    We compare H-alpha, radio continuum, and Spitzer Space Telescope (SST) images of 58 planetary nebulae (PNe) recently discovered by the Macquarie-AAO-Strasbo- urg H-alpha PN Project (MASH) of the SuperCOSMOS H-alpha Survey. Using InfraRed Array Camera (IRAC) data we define the IR colors of PNe and demonstrate good isolation between these colors and those of many other types of astronomical object. The only substantive contamination of PNe in the color-color plane we illustrate is due to YSOs. However, this ambiguity is readily resolved by the unique optical characteristics of PNe and their environs. We also examine the relationships between optical and MIR morphologies from 3.6 to 8.0um and explore the ratio of mid-infrared (MIR) to radio nebular fluxes, which is a valuable discriminant between thermal and nonthermal emission. MASH emphasizes late evolutionary stages of PNe compared with previous catalogs, enabling study of the changes in MIR and radio flux that attend the aging process. Spatially integrated MIR energy distributions were constructed for all MASH PNe observed by the GLIMPSE Legacy Project, using the H-alpha morphologies to establish the dimensions for the calculations of the Midcourse Space Experiment (MSX), IRAC, and radio continuum (from the Molonglo Observatory Synthesis Telescope and the Very Large Array) flux densities. The ratio of IRAC 8.0-um to MSX 8.3-um flux densities provides a measure of the absolute diffuse calibration of IRAC at 8.0 um. We independently confirm the aperture correction factor to be applied to IRAC at 8.0um to align it with the diffuse calibration of MSX. The result agrees with the recommendations of the Spitzer Science Center and with results from a parallel study of HII regions. These PNe probe the diffuse calibration of IRAC on a spatial scale of 9-77 arcsec.Comment: 48 pages, LaTeX (aastex), incl. 18 PostScript (eps) figures and 3 tables. Accepted by Astrophysical Journa

    Effect of a brief intervention on evidence-based medicine skills of pediatric residents

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    BACKGROUND: While Evidence-Based Medicine (EBM) skills are increasingly being taught in medical schools, teaching quality has been insufficient, so that incoming pediatric residents lack adequate EBM skills required for patient care. The objective of this study was to evaluate the effectiveness of a brief teaching module developed to improve EBM skills of pediatric residents. METHODS: With-in subjects study design with pre- and post-test evaluation was performed in a large urban pediatric residency training program in Brooklyn, New York. We included PGY-1s during intern orientation, while second and third year pediatric residents were selected based on schedule availability. Sixty-nine residents were enrolled into the study, 60 (87%) completed the training. An EBM training module consisting of three or four weekly two-hour seminars was conducted. The module was designed to teach core EBM skills including (1) formulating answerable clinical questions, (2) searching the evidence, (3) critical appraisal skills including validity and applicability, and (4) understanding levels of evidence and quantitative results for therapy articles. A portion of the Fresno test of competence in EBM was used to assess EBM skills. The test presented a clinical scenario that was followed by nine short answer questions. One to three questions were used to assess EBM skills for each of the four core skills. The Îș co-efficient for inter-rater reliability was 0.74 (95% CI: 0.56–0.92). RESULTS: Prior to the training module, the residents achieved a mean score of 17% correct overall. Post intervention, the mean score increased to 63% with improvement in each EBM category. A mean of 4.08 more questions (out of 9) were answered correctly after the training (95% CI of 3.44–4.72). CONCLUSION: A brief training module was effective in improving EBM skills of pediatric residents

    G313.3+00.3: A New Planetary Nebula discovered by the Australia Telescope Compact Array and the Spitzer Space Telescope

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    We present a new planetary nebula, first identified in images from the Australia Telescope Compact Array, although not recognized at that time. Recent observations with the Spitzer Space Telescope during the GLIMPSE Legacy program have rediscovered the object. The high-resolution radio and infrared images enable the identification of the central star or its wind, the recognition of the radio emission as thermal, and the probable presence of polycylic aromatic hydrocarbons in and around the source. These lead to the conclusion that G313.3+00.3 is a planetary nebula. This object is of particular interest because it was discovered solely through radio and mid-infrared imaging, without any optical (or near-infrared) confirmation, and acts as a proof of concept for the discovery of many more highly extinguished planetary nebulae. G313.3+00.3 is well-resolved by both the instruments with which it was identified, and suffers extreme reddening due to its location in the Scutum-Crux spiral arm.Comment: 18 pages, LaTeX (aastex), incl. 8 PostScript (eps) figures and 1 table. Accepted by ApJ (Part 1

    Growth and Diversification of Doctoral Education in the United Kingdom

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    The chapter analyses the growth in numbers of doctoral students and doctoral degrees awarded in the United Kingdom in recent years and develops two arguments related to this growth. First, doctoral education and training no longer serve almost exclusively the reproduction of the academic profession but provide a highly qualified workforce for the knowledge-intensive sectors of society. Second, due to the growth in the numbers, motives and purposes for obtaining a doctoral degree have diversified leading to the development of new routes towards a doctorate and an expansion in the types of doctoral degree. The United Kingdom is probably the European country with the highest degree of diversity in terms of doctoral degree types, and the most important ones are briefly described in the chapter. This second part will also include a brief discussion of nonacademic labour markets for doctoral degree holders. A third part of the chapter will look at the extended policy field into which doctoral education and training have increasingly been embedded in recent years. Given the fact that doctoral degree holders are a valuable resource (e.g. in human capital terms) for various economic sectors of the knowledge society, their education and training is no longer considered to be exclusively an academic affair. Instead, it is increasingly managed at institutional level and guided by policy processes at national and – at least in Europe – at supranational level. The fourth and final part of the chapter will discuss the question of the growing divergence or growing convergence in doctoral education and training. It is assumed that, despite the growing diversity of pathways and doctoral degree types, there is also some convergence at play – at least at the European level – in so far as quality assurance, definitions of skills and qualifications as well as procedures for the examination and award of degrees are increasingly subject to standards, rules and regulations defined by the European network of quality assurance agencies. It remains to be seen whether the exit of the United Kingdom from the European Union will have an impact on, or even reverse, this trend

    A Spitzer Space Telescope Infrared Survey of Supernova Remnants in the Inner Galaxy

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    Using Infrared Array Camera (IRAC) images at 3.6, 4.5, 5.8, and 8 microns from the GLIMPSE Legacy science program on the Spitzer Space Telescope, we searched for infrared counterparts to the 95 known supernova remnants that are located within galactic longitudes 65>|l|>10 degrees and latitudes |b|<1 degree. Eighteen infrared counterparts were detected. Many other supernova remnants could have significant infrared emission but are in portions of the Milky Way too confused to allow separation from bright HII regions and pervasive mid-infrared emission from atomic and molecular clouds along the line of sight. Infrared emission from supernova remnants originates from synchrotron emission, shock-heated dust, atomic fine-structure lines, and molecular lines. The detected remnants are G11.2-0.3, Kes 69, G22.7-0.2, 3C 391, W 44, 3C 396, 3C 397, W 49B, G54.4-0.3, Kes 17, Kes 20A, RCW 103, G344.7-0.1, G346.6-0.2, CTB 37A, G348.5-0.0, and G349.7+0.2. The infrared colors suggest emission from molecular lines (9 remnants), fine-structure lines (3), and PAH (4), or a combination; some remnants feature multiple colors in different regions. None of the remnants are dominated by synchrotron radiation at mid-infrared wavelengths. The IRAC-detected sample emphasizes remnants interacting with relatively dense gas, for which most of the shock cooling occurs through molecular or ionic lines in the mid-infrared.Comment: Accepted 10/18/2005 for publication in "The Astronomical Journal". The figures in this astro-ph submission are drastically reduced in quality in order to fit within its limit

    Engaging African American breast cancer survivors in an intervention trial: culture, responsiveness and community

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    Younger breast cancer survivors often lead extremely busy lives with multiple demands and responsibilities, making them difficult to recruit into clinical trials. African American women are even more difficult to recruit because of additional historical and cultural barriers. In a randomized clinical trial of an intervention, we successfully used culturally informed, population-specific recruitment and retention strategies to engage younger African-American breast cancer survivors

    Social Value of Marine and Coastal Protected Areas in England and Wales.

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    The U.K. government is committed to establishing a coherent network of marine protected areas by 2012 and the recentMarine and Coastal Access Act, 2009 will designate marine conservation zones and provide wider access rights to the coast. To fulfill these goals, this article argues the need for a clearer, shared understanding of the social value of protected areas in creating new designations and managing existing ones. Although marine and coastal environments attract many people and are vitally important in terms of realized and potential social value, the majority of the public in the United Kingdom lacks understanding and awareness regarding them. Combined with this, the social value of marine and coastal protected areas (MCPAs) have been largely ignored relative to conservation and economics, with the latter invariably taking precedence in environmental policymaking. Social value reflects the complex, individual responses that people experience in a given place. Many reasons determine why one area is valued above another, and this research investigates the social value of MCPAs from a practitioner’s perspective through a series of interviews. Understanding why we “socially” value MCPAs will ultimately equip managers with an informed understanding of these spaces, influence management decisions, and, potentially, policymaking. This article defines social value in the context of MCPAs in England and Wales from a practitioner perspective, explores key concepts, and suggests possible improvements in decision-making

    Livestock trade networks for guiding animal health surveillance

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    BACKGROUND: Trade in live animals can contribute to the introduction of exotic diseases, the maintenance and spread endemic diseases. Annually millions of animals are moved across Europe for the purposes of breeding, fattening and slaughter. Data on the number of animals moved were obtained from the Directorate General Sanco (DG Sanco) for 2011. These were converted to livestock units to enable direct comparison across species and their movements were mapped, used to calculate the indegrees and outdegrees of 27 European countries and the density and transitivity of movements within Europe. This provided the opportunity to discuss surveillance of European livestock movement taking into account stopping points en-route. RESULTS: High density and transitivity of movement for registered equines, breeding and fattening cattle, breeding poultry and pigs for breeding, fattening and slaughter indicates that hazards have the potential to spread quickly within these populations. This is of concern to highly connected countries particularly those where imported animals constitute a large proportion of their national livestock populations, and have a high indegree. The transport of poultry (older than 72 hours) and unweaned animals would require more rest breaks than the movement of weaned animals, which may provide more opportunities for disease transmission. Transitivity is greatest for animals transported for breeding purposes with cattle, pigs and poultry having values of over 50%. CONCLUSIONS: This paper demonstrated that some species (pigs and poultry) are traded much more frequently and at a larger scale than species such as goats. Some countries are more vulnerable than others due to importing animals from many countries, having imported animals requiring rest-breaks and importing large proportions of their national herd or flock. Such knowledge about the vulnerability of different livestock systems related to trade movements can be used to inform the design of animal health surveillance systems to facilitate the trade in animals between European member states. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12917-015-0354-4) contains supplementary material, which is available to authorized users
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