1,862 research outputs found

    The hydrostatic equilibrium and Tsallis equilibrium for self-gravitating systems

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    Self-gravitating systems are generally thought to behavior non-extensively due to the long-range nature of gravitational forces. We obtain a relation between the nonextensive parameter q of Tsallis statistics, the temperature gradient and the gravitational potential based on the equation of hydrostatic equilibrium of self-gravitating systems. It is suggested that the nonextensive parameter in Tsallis statistics has a clear physical meaning with regard to the non-isothermal nature of the systems with long-range interactions and Tsallis equilibrium distribution for the self-gravitating systems describes the property of hydrostatic equilibrium of the systems.Comment: 7 pages, 9 Reference

    Investigation of charge sharing among electrode strips for a CdZnTe detector

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    We have investigated charge sharing among the anode strips of a CdZnTe (CZT) detector using a 30 micrometer collimated gamma-ray beam. We compared the laboratory measurements with the predictions from our modeling of the charge transport within the detector. The results indicate that charge sharing is a function of the interaction depth and the energy of the incoming photon. Also, depending on depth, a fraction of the electrons might drift to the inter-anode region causing incomplete charge collection. Here, we show that photoelectron range and diffusion of the charge cloud are the principal causes of charge sharing and obtain limits on the size of the electron cloud as a function of position in the detector.Comment: 16 pages 10 figures. Accepted for publication in Nuclear Instruments and Methods -

    Quantum games of asymmetric information

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    We investigate quantum games in which the information is asymmetrically distributed among the players, and find the possibility of the quantum game outperforming its classical counterpart depends strongly on not only the entanglement, but also the informational asymmetry. What is more interesting, when the information distribution is asymmetric, the contradictive impact of the quantum entanglement on the profits is observed, which is not reported in quantum games of symmetric information.Comment: 5 pages, 3 figure

    Phaeochrornocytorna - a case report

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    A 52-year-old man presented with a 4-year history of paroxysmal attacks of anxiety, giddiness, palpitation, sweating, and severe headache. These symptoms wereassociated with sudden increases in his blood pressure; and a provisional diagnosis of phaeochromocytoma was made.Collections of urine were submitted for catecholamine assay. One collection showed a slight increase in catecholamines but the rest were normal, including a collection made after a provocation test, using histamine 0,025 mg intravenously. The histamine test did, however, cause systolic and diastolic blood pressure to rise by 20 mmHg.As he was mildly hypertensive between paroxysms, a phentolamine test was carried out, utilising 5 mg well diluted, intravenously, over 5 minutes under basal conditions. This, too, was negative. An aortogram failed to demonstrate convincingly tumour vascularisation, but there was a mild hypertensive crisis during this examination.At laparotomy, a single phaeochromocytoma was found in the right adrenal gland, and was successfully removed. Recovery was uneventful and the patient was discharged, normotensive and not requiring hypotensive therapy, though mild hypertension has developed since. No residual catecholamine activity has been detected.The preparation of the patient for surgery and the control of operative complications are described, and the salient diagnostic features of phaeochromocytoma are briefly discussed.S. Afr. Med. J. 48, 401 (1974)

    An in vitro test to demonstrate the inhibitory effect of homologous immune serum on the infectivity of Cowdria ruminantium

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    Homologous immune sheep serum inhibits the infectivity of mice for the Kumm stock of Cowdria ruminantium in an in vitro test. The presence of complement and an optimal ratio between the reagents are of cardinal importance. With the exception of the Ball 3 stock, there is no cross-inhibition between the immune sera of sheep infected with several other heterologous stocks and the Kumm stock. The role played by the humoral component of the immune response in naturally acquired heartwater is unknown, but probably small compared to the cellular component.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

    The natural resistance of cattle to artificial infection with Cowdria ruminantium: the role played by conglutinin

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    The conglutinin titres of year-old Bonsmara-cross cattle infected with Cowdria ruminantium were inversely proportional to the severity of the reactions elicited by the infection. There was no correlation, however, between conglutinin levels of 8-month-old calves of the same breed, sex and origin and their susceptibility to heartwater. The role possibly played by conglutinin in the non-specific resistance of cattle to heartwater and in the epidemiology of the disease is discussed.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

    Increased pathogenicity of an Ehrlichia-like agent after passage through Amblyomma hebraeum : a preliminary report

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    After being passaged through 3 generations of Amblyomma hebraeum, an Ehrlichia-like agent isolated from an adult Hyalomma truncatum female became more pathogenic and elicited a disease in sheep indistinguishable from heartwater. Cross-immunity between this agent and several stocks of Cowdria ruminantium and high levels of antibody elicited by the agent against 2 stocks of C. ruminantium in the indirect fluorescent antibody test, confirmed its close relationship to Cowdria.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

    The influence of dithiosemicarbazone on the immunity of sheep to heartwater

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    Four out of 9 sheep, immune to heartwater and subsequently treated with gloxazone, showed a febrile reaction when they were challenged 6 months later, but the same number of untreated controls also developed this reaction. In a second group of treated immune animals challenged after 9 months, 8 out of 8 showed a febrile reaction, whereas only 3 out of 8 controls reacted. Furthermore, the blood of one of the 4 sheep that reacted to challenge at 6 months was infective to a susceptible sheep inoculated with it, whereas that of 4 out of the 8 challenged at 9 months was infective.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

    Pathogenesis of heartwater. I. Cowdria ruminantium in the lymph nodes of domestic ruminants

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    The intracellular replication of Cowdria ruminantium (Cowdry, 1926) is described in reticulum cells of lymph nodes several days prior to the appearance of rickettsial colonies in vascular endothelial cells. This is suggestive of a developmental cycle of the parasite in the lymph nodes. The subinoculation of suspensions of these glands resulted in transmission of the disease.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.
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