5,693 research outputs found

    Correlation of the Havemeyer endoscopic laryngeal grading system with histopathological changes in equine Cricoarytenoideus dorsalis muscles

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    The establishment of a single validated endoscopic laryngeal grading system for assessing recurrent laryngeal neuropathy (RLN) is desirable to facilitate direct comparisons between the findings of different clinical and research groups worldwide. The objective of this study was to assess the relationship between the Havemeyer endoscopic laryngeal grading system and histopathological changes consistent with RLN in the left cricoarytenoideus dorsalis (CAD) muscle of horses of different breeds with a full range of clinical severities of RLN, i.e., from normal endoscopic laryngeal function to complete laryngeal hemiplegia. Endoscopic grading of laryngeal function of 22 horses was performed using the Havemeyer endoscopic laryngeal grading system. A biopsy sample of the left CAD muscle was obtained from each horse, either at post mortem examination (n = 16), or during routine laryngoplasty surgery (n = 6). A semi-quantitative histopathological scoring system was used to grade the severity of histopathological lesions consistent with RLN in the left CAD muscle of each horse. A significant positive correlation (rs = 0.705, p < 0.001) was found between the Havemeyer grades and sub-grades of laryngeal function and the semi-quantitative assessment of histopathological lesions consistent with RLN in the left CAD muscle. However, a wide spread of muscle histopathological scores was obtained, particularly from horses with Havemeyer sub-grades II.1, III.1 and III.2. In conclusion, the Havemeyer endoscopic laryngeal grading system was found to broadly correlate with histopathological changes consistent with RLN in equine cricoarytenoideus dorsalis muscle

    The structure of intercalated water in superconducting Na0.35_{0.35}CoO2_{2}\cdot1.37D2_{2}O: Implications for the superconducting phase diagram

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    We have used electron and neutron powder diffraction to elucidate the structural properties of superconducting \NaD. Our measurements show that our superconducting sample exhbits a number of supercells ranging from 1/3a{1/3}a^{*} to 1/15a{1/15}a^{*}, but the most predominant one, observed also in the neutron data, is a double hexagonal cell with dimensions \dhx. Rietveld analysis reveals that \deut\space is inserted between CoO2_{2} sheets as to form a layered network of NaO6_{6} triangular prisms. Our model removes the need to invoke a 5K superconducting point compound and suggests that a solid solution of Na is possible within a constant amount of water yy.Comment: 4 pages, 3 figure

    Exciton energy transfer in nanotube bundles

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    Photoluminescence is commonly used to identify the electronic structure of individual nanotubes. But, nanotubes naturally occur in bundles. Thus, we investigate photoluminescence of nanotube bundles. We show that their complex spectra are simply explained by exciton energy transfer between adjacent tubes, whereby excitation of large gap tubes induces emission from smaller gap ones via Forster interaction between excitons. The consequent relaxation rate is faster than non-radiative recombination, leading to enhanced photoluminescence of acceptor tubes. This fingerprints bundles with different compositions and opens opportunities to optimize them for opto-electronics.Comment: 5 pages, 5 figure

    A high-resolution radio survey of the Vela supernova remnant

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    This paper presents a high-resolution radio continuum (843 MHz) survey of the Vela supernova remnant. The contrast between the structures in the central pulsar-powered nebula of the remnant and the synchrotron radiation shell allows the remnant to be identified morphologically as a member of the composite class. The data are the first of a composite remnant at spatial scales comparable with those available for the Cygnus Loop and the Crab Nebula, and make possible a comparison of radio, optical and soft X-ray emission from the resolved shell filaments. The survey, made with the Molonglo Observatory Synthesis Telescope, covers an area of 50 square degrees at a resolution of 43'' x 60'', while imaging structures on scales up to 30'.Comment: 18 pages, 7 jpg figures (version with ps figures at http://astro.berkeley.edu/~dbock/papers/); AJ, in pres

    The Distance to the Cygnus Loop from Hubble Space Telescope Imaging of the Primary Shock Front

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    We present a Hubble Space Telescope/WFPC2 narrow-band H-alpha image of a region on the northeastern limb of the Cygnus Loop supernova remnant. This location provides a detailed example of where the primary blast wave first encounters the surrounding interstellar medium. The filament structure is seen in exquisite detail in this image, which was obtained primarily as an EARLY ACQuisition image for a follow-up spectroscopic program. We compare the HST image to a digitized version of the POSS-I red plate to measure the proper motion of this filament. By combining this value for the proper motion with previous measurements of the shock velocity at this position we find that the distance to the Cygnus Loop is 440 (+130, -100) pc, considerably smaller than the canonical value of 770 pc. We briefly discuss the ramifications of this new distance estimate for our understanding of this prototypical supernova remnant.Comment: 18 pages, 3 Figures (2 JPEG and one Postscript

    Evidence of a Curved Synchrotron Spectrum in the Supernova Remnant SN 1006

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    A joint spectral analysis of some Chandra ACIS X-ray data and Molonglo Observatory Synthesis Telescope radio data was performed for 13 small regions along the bright northeastern rim of the supernova remnant SN 1006. These data were fitted with a synchrotron radiation model. The nonthermal electron spectrum used to compute the photon emission spectra is the traditional exponentially cut off power law, with one notable difference: The power-law index is not a constant. It is a linear function of the logarithm of the momentum. This functional form enables us to show, for the first time, that the synchrotron spectrum of SN 1006 seems to flatten with increasing energy. The effective power-law index of the electron spectrum is 2.2 at 1 GeV (i.e., radio synchrotron-emitting momenta) and 2.0 at about 10 TeV (i.e., X-ray synchrotron-emitting momenta). This amount of change in the index is qualitatively consistent with theoretical models of the amount of curvature in the proton spectrum of the remnant. The evidence of spectral curvature implies that cosmic rays are dynamically important instead of being "test" particles. The spectral analysis also provides a means of determining the critical frequency of the synchrotron spectrum associated with the highest-energy electrons. The critical frequency seems to vary along the northeastern rim, with a maximum value of 1.1e17 (0.6e17 - 2.1e17) Hz. This value implies that the electron diffusion coefficient can be no larger than a factor of ~4.5-21 times the Bohm diffusion coefficient if the velocity of the forward shock is in the range 2300-5000 km/s. Since the coefficient is close to the Bohm limit, electrons are accelerated nearly as fast as possible in the regions where the critical frequency is about 1.0e17 Hz.Comment: 41 pages, 8 figures, accepted by Ap

    Books

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    Ask the Doctor. Hypertension By Vincent Friedewald. Pp. xiv + 120. R59.95. Kansas City:Andrews and McMeel. ISBN 0-8362-7022-3.How to Survive in Anaesthesia*By P Neville Robinson and George M Hall. Pp. xi + 172. £22.00.1997. London: BMJ. ISBN 0-7279-1066-3.Epidemiology. A Manual for South Africa* Edited by J M Katzenellenbogen, G Joubert and S S Abdool Karim. Pp. 295. R120. 1997. Cape Town: Oxford University Press. ISBN 0-19-571308-7

    On the edge of a new frontier: Is gerontological social work in the UK ready to meet twenty-first-century challenges?

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    This article is available open access through the publisher’s website. Copyright @ 2013 The Authors.This article explores the readiness of gerontological social work in the UK for meeting the challenges of an ageing society by investigating the focus on work with older people in social work education and the scope of gerontological social work research. The discussion draws on findings from two exploratory studies: a survey of qualifying master's programmes in England and a survey of the content relating to older people over a six-year period in four leading UK social work journals. The evidence from master's programmes suggests widespread neglect of ageing in teaching content and practice learning. Social work journals present a more nuanced picture. Older people emerge within coverage of generic policy issues for adults, such as personalisation and safeguarding, and there is good evidence of the complexity of need in late life. However, there is little attention to effective social work interventions, with an increasingly diverse older population, or to the quality of gerontological social work education. The case is made for infusing content on older people throughout the social work curriculum, for extending practice learning opportunities in social work with older people and for increasing the volume and reporting of gerontological social work research.Brunel Institute for Ageing Studie
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