1,400 research outputs found

    Constructing Infinitary Quotient-Inductive Types

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    This paper introduces an expressive class of quotient-inductive types, called QW-types. We show that in dependent type theory with uniqueness of identity proofs, even the infinitary case of QW-types can be encoded using the combination of inductive-inductive definitions involving strictly positive occurrences of Hofmann-style quotient types, and Abel's size types. The latter, which provide a convenient constructive abstraction of what classically would be accomplished with transfinite ordinals, are used to prove termination of the recursive definitions of the elimination and computation properties of our encoding of QW-types. The development is formalized using the Agda theorem prover.Comment: The accompanying Agda code can be found at https://doi.org/10.17863/CAM.4818

    Accurate laboratory wavelengths of the e 3 Σ–(ν' = 5) – X 1 Σ+(ν'' = 0) band of 12C16O

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    CITATION: Dickenson, G. D. et al. 2010. Accurate laboratory wavelengths of the e 3 Σ–(ν' = 5) – X 1 Σ+(ν'' = 0) band of 12C16O. Astrophysical Journal Letters, 714(2):L268–L270, doi:10.1088/2041-8205/714/2/L268.The original publication is available at https://iopscience.iop.org/journal/2041-8205The forbidden singlet-triplet transitions of carbon monoxide (CO) are important in the interpretation of vacuum ultraviolet interstellar absorption spectra and in particular for the measurement of large CO column densities. Twenty rovibronic lines of the e 3Σ–(ν' = 5) – X 1Σ+(ν'' = 0) band of 12 C 16O for which laboratory wavelengths were previously unavailable were identified in laser-induced fluorescence excitation spectra. Wavelengths were assigned to five rovibronic transitions to an average accuracy of 0.0028 Å. A further 15 lines could not be fully resolved and average wavelengths were measured for these groups of closely spaced lines. A wavelength difference of 0.011 ± 0.0028 Å between the measured wavelengths and the calculated wavelengths in the atlas of Eidelsberg & Rostas demonstrates the need for more experimental data on CO.https://iopscience.iop.org/article/10.1088/2041-8205/714/2/L268Publisher's versio

    Measurement of antiacetylcholine receptor auto-antibodies in myasthenia gravis

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    Two different acetylcholine receptor (AChR) preparations derived from amputated human muscle (AChRAMP) and from the human rhabdomyosarcoma cell line TE671 (AChRTE67,) were compared in radio-immunoprecipitation assays for the detection of AChR auto-antibodies in serum specimens from 20 patients with proven myasthenia gravis. Tests performed with the AChRTE67, and AChRAMP antigen preparations were positive in all the patients and in 19/20 respectively. A high degree of correlation (r = 0,94) was evident between the two auto-antigen preparations. Assays based on the use of TE671-derived antigen represent a useful alternative to the conventional assay using AChRAMP  for the detection of AChR autoantibodies

    Neurodevelopmental evaluation and referral practices in children with congenital heart disease in central South Africa

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    Introduction: Children with congenital heart disease (CHD) are at higher risk for developmental delays than the general population. The American Heart Association (AHA) published a guideline to address these concerns in 2012. This study determined the neurodevelopmental evaluation and referral practices of practitioners in central South Africa.Method: An online survey was administered to practitioners (n=45) including paediatric cardiologists (n=4), cardiothoracic surgeons (n=4) and general paediatricians (n=37). Information on practitioner characteristics, awareness of the 2012 AHA guideline; and neurodevelopmental evaluation and referral practices was collected.Results: Twenty-one practitioners responded, including paediatric cardiologists (n=4), cardiothoracic surgeons (n=2) and paediatricians (n=15). Data for 20 practitioners was included. Despite most practitioners (n=18) indicating guidelines for the management of development were important, the majority (n=16; 80%) were unaware of the guideline. Most practitioners (n=18; 90%) failed to risk stratify children to identify those to be evaluated. Children with developmental delays were referred for formal developmental evaluation (n=11; 55%) and to intervention therapies (n= 15; 75%).Conclusion: Most practitioners are unaware of the 2012 AHA guideline. Awareness of the developmental risks associated with CHD and implementation of the guideline could promote early identification of developmental delays with referral to intervention therapies

    Book Reviews

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    Basic Neurology. Ed. by J. Gilroy and P. L. Holliday. Pp. vii + 373. Illustrated. R27,90. London: Macmillan. 1982.The Pathology of the Heart. By E. G. J. Olsen. Pp. ix + 402. Illustrated. R91,85. London: Macmillan. 1982.Profile of Disease and Health Care in South Africa. By H. C. J. van Rensburg and A. Mans. Pp. xvii + 319. R29,50. Pretoria: Academica Press. 1982.Principles of Ambulatory Medicine. Ed. by L. R. Barker, J. R. Burton and P. D. Zieve. Pp. xiii + 1127. Illustrated. R78,-. Baltimore, Maryland: Williams & Wilkins. 1982.Topical Reviews in Accident Surgery, vol. 2. Ed. by N. Tubbs and P. S. London. Pp. ix +258. Illustrated. £18,50. London: Wright PSG.1982.Early Care of the Injured Patient. 3rd ed. Ed. by A. J. Wait, L. F. Peltier, B. A. Pruitt jun, D. D. Trunkey and R. F. Wilson. Pp. xv + 413. Illustrated. Philadelphia: W. B. Saunders. 1982.Current Pediatric Therapy. 10th ed. By S. S. Gellis and B. M. Kagan. Pp. xxxviii + 776. R94,25. Philadelphia: W. B. Saunders. 1982.Selected Techniques in Interventional Radiology,vol. 19 (Saunders Monographs in Clinical Radiology). By S. Kadir, S. L. Kaufman, K. H. Barth and R. 1. White jun. Pp. xi +216. Illustrated. R76,75. Philadelphia: W. B. Saunders. 1982.Clinical Topics in Internal Medicine. Ed. by G. M. Tisi and H. M. Ranney. Pp. xii 173. Illustrated. Baltimore, Maryland: Williams & Wilkins. 1982.Recognizable Patterns of Human Malformation: Genetic Embryologic and Clinical Aspects (Major Problems in Clinical Pediatrics, vo!. vii). 3rd ed. By W. David and M. D. Smith. Pp. xvii + 653. Illustrated. R78,55. Philadelphia: W. B. Saunders. 1982.The Patient and the Plastic Surgeon. By R. M. Goldwyn. Pp. xiii + 255. Boston: Little, Brown. 1981.The Aging Lumbar Spine. By S. W. Wiesel, P. Bernini and R. H. Rothman. Pp. 257. Illustrated. R69,55. Philadelphia: W. B. Saunders. 1982.Postoperative Complications of Intracranial Neurological Surgery. By N. H. Horwitz and H. V. Rizzoli. Pp. xi + 472. Illustrated. Baltimore: Williams & Wilkins. 1982.Current Topics in Inflammation and Infection (International Academy of Pathology Monograph). Ed. by G. Majno, R. S. Cotran and . Kaufman. Pp. xi + 242. Illustrated. Baltimore, Maryland: Williams & Wilkins. 1982.Radiology of the Ear, Nose and Throat. By G. E. Valvassori, G. D. Porter, W. N. Hanafee, B. L. Carter and R. A. Buckingham. Pp. viii + 342. Illustrated. RI94,30. Philadelphia: \Y/. B. Saunders. 1982.Neuropathology ofParasitic Infections. By W. J. Brown and M. Voge. Pp. 240. Illustrated. RI5,-. Oxford: Oxford Medical Publishers. 1982.Herzkrankheiten: Pathophysiologie, Diagoostik, Therapie. 2nd ed. By H. Roskamm and H. Reindel!. Pp. xxxiii + 1543. Illustrated. DM 278,-. Berlin: Springer-Verlag. 1982.Review ofSpeech, Language and Hearing, vols I, 2and 3. By N. J. Lass, L. V. McReynolds, J. L. Northern and D. E. Yoder. Illustrated. R36,20 each. Philadelphia: W. B. Saunders. 1982

    First detection of a VHE gamma-ray spectral maximum from a Cosmic source: H.E.S.S. discovery of the Vela X nebula

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    The Vela supernova remnant (SNR) is a complex region containing a number of sources of non-thermal radiation. The inner section of this SNR, within 2 degrees of the pulsar PSR B0833-45, has been observed by the H.E.S.S. gamma-ray atmospheric Cherenkov detector in 2004 and 2005. A strong signal is seen from an extended region to the south of the pulsar, within an integration region of radius 0.8 deg. around the position (RA = 08h 35m 00s, dec = -45 deg. 36' J2000.0). The excess coincides with a region of hard X-ray emission seen by the ROSAT and ASCA satellites. The observed energy spectrum of the source between 550 GeV and 65 TeV is well fit by a power law function with photon index = 1.45 +/- 0.09(stat) +/- 0.2(sys) and an exponential cutoff at an energy of 13.8 +/- 2.3(stat) +/- 4.1(sys) TeV. The integral flux above 1 TeV is (1.28 +/- 0.17 (stat) +/- 0.38(sys)) x 10^{-11} cm^{-2} s^{-1}. This result is the first clear measurement of a peak in the spectral energy distribution from a VHE gamma-ray source, likely related to inverse Compton emission. A fit of an Inverse Compton model to the H.E.S.S. spectral energy distribution gives a total energy in non-thermal electrons of ~2 x 10^{45} erg between 5 TeV and 100 TeV, assuming a distance of 290 parsec to the pulsar. The best fit electron power law index is 2.0, with a spectral break at 67 TeV.Comment: 5 pages, 4 figures, accepted for publication in Astronomy and Astrophysics letter

    Observations of Mkn 421 in 2004 with H.E.S.S. at large zenith angles

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    Mkn 421 was observed during a high flux state for nine nights in April and May 2004 with the fully operational High Energy Stereoscopic System (H.E.S.S.) in Namibia. The observations were carried out at zenith angles of 60^\circ--65^\circ, which result in an average energy threshold of 1.5 TeV and a collection area reaching 2~km2^2 at 10~TeV. Roughly 7000 photons from Mkn~421 were accumulated with an average gamma-ray rate of 8 photons/min. The overall significance of the detection exceeds 100 standard deviations. The light-curve of integrated fluxes above 2~TeV shows changes of the diurnal flux up to a factor of 4.3. For nights of high flux, intra-night variability is detected with a decay time of less than 1 hour. The time averaged energy spectrum is curved and is well described by a power-law with a photon index \egamm and an exponential cutoff at \ecut~TeV and an average integral flux above 2~TeV of 3 Crab flux units. Significant variations of the spectral shape are detected with a spectral hardening as the flux increases. Contemporaneous multi-wavelength observations at lower energies (X-rays and gamma-rays above 300\approx 300~GeV) indicate smaller relative variability amplitudes than seen above 2~TeV during high flux state observed in April 2004.Comment: 5 pages, 4 figures, published in A&

    Very high energy gamma rays from the direction of Sagittarius A*.

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    We report the detection of a point-like source of very high energy (VHE) -rays coincident within 1' of Sgr A *, obtained with the HESS array of Cherenkov telescopes. The -rays exhibit a power-law energy spectrum with a spectral index of and a flux above the 165 GeV threshold of m -2 s -1. The measured flux and spectrum differ substantially from recent results reported in particular by the CANGAROO collaboration
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