1,317 research outputs found
Constructing Infinitary Quotient-Inductive Types
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
Measurement of antiacetylcholine receptor auto-antibodies in myasthenia gravis
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
Non-western contexts: the invisible half
Like many other disciplines within the broad area of social sciences (e.g., anthropology, gender studies, psychology, sociology, etc.), consumer research is also highly navigated by scholars from Western countries. This, however, does not mean, by any means, that consumer research is devoted to studying Western contexts only. As evident from the ever-increasing number of regional conferences (e.g., Asia-Pacific and Latin American conferences of the Association for Consumer Research) and non-Western students' enrolment in doctoral programs at Western universities, there are many more researchers (from non-Western countries) who are entering the field and enriching it by their colourful contributions. Yet, given the low number of publications on consumer research in non-Western contexts, it seems that our current knowledge in these societies has a long way to go to flourish. More specifically, and in the domain of consumption culture research, this gap is even further widened by the fact that the culture of consumption in such contexts is largely interpreted with reference to the 'grand narratives' of Western scholars (e.g., Foucault, Mafessoli, Bourdieu, Deleuze, Baudrillard, Nietzsche, Durkheim, Derrida, etc.). Therefore, from an ontological perspective, it seems that our existing knowledge about non-Western societies lies heavily on the 'theoretical structures' that are 'constructed' by Western philosophy as a set of ideas, beliefs, and practices (Said, 1978). As Belk (1995) reminds us, consumption culture always existed in all human societies. What makes contemporary societies different from that of our predecessors' is not the fact that consumption culture did not exist in those societies, but that consumption culture has become a prevailing feature in modern society (Slater, 1997; Lury, 1996; Fırat and Venkatesh, 1995; McCracken, 1988). Therefore, the nature and dynamics of consumption culture in each society should be studied not only against the sociocultural, historical, and economic background of a given context (Western or non-Western) but also with reference to the philosophical and epistemological viewpoints that analyse and interpret cultural practices of that society from within that culture. Addressing such issues, this paper discusses some of the key reasons for lack of theory development in the field from non-western contexts. The paper invites scholars in non-Western contexts to introduce the less articulated, and sometime hidden, body of knowledge from their own contexts into the field of marketing in general and consumer research in particular
Dental pathology in a wild serval (Leptailurus serval) population
Members of the family Felidae suffer from a wide range of dental, oral and maxillofacial conditions that can cause significant morbidity and mortality. Although many dental, oral and maxillofacial anomalies of the domestic cat (Felis catus) also occur in wild felines, we could find no investigations of these conditions in servals (Leptailurus serval). The objective of this study was to describe the dental, oral and maxillofacial pathology of a wild serval population in South Africa. Detailed extraoral and intraoral examinations and full-mouth dental radiographs on 30 wild servals revealed 14 different dental conditions but no other oral or maxillofacial pathology.Secunda Synfuels Operationshttp://elsevier.com/locate/jcpahj2021Centre for Veterinary Wildlife StudiesCompanion Animal Clinical Studie
Book Reviews
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
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
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--65, which result in an average energy threshold of 1.5 TeV
and a collection area reaching 2~km 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
~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&
H.E.S.S. observations of gamma-ray bursts in 2003-2007
Very-high-energy (VHE; >~100 GeV) gamma-rays are expected from gamma-ray
bursts (GRBs) in some scenarios. Exploring this photon energy regime is
necessary for understanding the energetics and properties of GRBs. GRBs have
been one of the prime targets for the H.E.S.S. experiment, which makes use of
four Imaging Atmospheric Cherenkov Telescopes (IACTs) to detect VHE gamma-rays.
Dedicated observations of 32 GRB positions were made in the years 2003-2007 and
a search for VHE gamma-ray counterparts of these GRBs was made. Depending on
the visibility and observing conditions, the observations mostly start minutes
to hours after the burst and typically last two hours. Results from
observations of 22 GRB positions are presented and evidence of a VHE signal was
found neither in observations of any individual GRBs, nor from stacking data
from subsets of GRBs with higher expected VHE flux according to a
model-independent ranking scheme. Upper limits for the VHE gamma-ray flux from
the GRB positions were derived. For those GRBs with measured redshifts,
differential upper limits at the energy threshold after correcting for
absorption due to extra-galactic background light are also presented.Comment: 9 pages, 4 tables, 3 figure
Very high energy gamma rays from the direction of Sagittarius A*.
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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