875 research outputs found

    X-Linked Deafness in a South African Kindred

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    The X-linked deafness of Nance is present in a South African kindred. Recognition of the familial pattern of the disorder, together with the characteristic clinical and audiometric features, permits diagnostic precision, thereby facilitating accurate genetic counselling and rational management. Linkage studies indicated that the loci for the Xg blood group and the deafness gene are unlikely to be very close to each other.S. Afr. Med. J., 48, 587 (1974)

    X-linked deafness in a South African kindred

    Get PDF
    The X-linked deafness of Nance is present in a South African kindred. Recognition of the familial pattern of the disorder, together with the characteristic clinical and audiometric features, permits diagnostic precision, thereby facilitating accurate genetic counselling and rational management. Linkage studies indicated that the loci for the Xg blood group and the deafness gene are unlikely to be very close to each other.S. Afr. Med. J., 48, 587 (1974)

    Analytic treatment of CRIB Quantum Memories for Light using Two-level Atoms

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    It has recently been discovered that the optical analogue of a gradient echo in an optically thick material could form the basis of a optical memory that is both completely efficient and noise free. Here we present analytical calculation showing this is the case. There is close analogy between the operation of the memory and an optical system with two beam splitters. We can use this analogy to calculate efficiencies as a function of optical depth for a number of quantum memory schemes based on controlled inhomogeneous broadening. In particular we show that multiple switching leads to a net 100% retrieval efficiency for the optical gradient echo even in the optically thin case.Comment: 10 page

    Gradient Echo Quantum Memory for Light using Two-level Atoms

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    We propose a quantum memory for light that is analogous to the NMR gradient echo. Our proposal is ideally perfectly efficient and provides simplifications to current 3-level quantum memory schemes based on controlled inhomogeneous broadening. Our scheme does not require auxiliary light fields. Instead the input optical pulse interacts only with two-level atoms that have linearly increasing Stark shifts. By simply reversing the sign of the atomic Stark shifts, the pulse is retrieved in the forward direction. We present analytical, numerical and experimental results of this scheme. We report experimental efficiencies of up to 15% and suggest simple realizable improvements to significantly increase the efficiency.Comment: 4 pages, 4 figure

    Streptomycin ototoxicity in the unborn child

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    The original publication is available at http://www.samj.org.zaStreptomycin has been used in pregnant patients for more than 30 years. Some doubt, however, still exists with regard to its effects on the ear of the unborn child. Thirty-three children whose mothers had received streptomycin during pregnancy were followed up and their hearing tested. A minor degree of hearing loss which could possibly be due to the action of streptomycin was found in only 2 children.Publishers' versio

    Dynamic decoherence control of a solid-state nuclear quadrupole qubit

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    We report on the application of a dynamic decoherence control pulse sequence on a nuclear quadrupole transition in Pr3+:Y2SiO5Pr^{3+}:Y_2SiO_5 . Process tomography is used to analyse the effect of the pulse sequence. The pulse sequence was found to increase the decoherence time of the transition to over 30 seconds. Although the decoherence time was significantly increased, the population terms were found to rapidly decay on the application of the pulse sequence. The increase of this decay rate is attributed to inhomogeneity in the ensemble. Methods to circumvent this limit are discussed.Comment: 4 pages, 6 figure

    Risk factors for chest infection in acute stroke: a prospective cohort study

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    <p><b>Background and Purpose:</b> Pneumonia is a major cause of morbidity and mortality after stroke. We aimed to determine key characteristics that would allow prediction of those patients who are at highest risk for poststroke pneumonia.</p> <p><b>Methods:</b> We studied a series of consecutive patients with acute stroke who were admitted to hospital. Detailed evaluation included the modified National Institutes of Health Stroke Scale; the Abbreviated Mental Test; and measures of swallow, respiratory, and oral health status. Pneumonia was diagnosed by set criteria. Patients were followed up at 3 months after stroke.</p> <p><b>Results:</b> We studied 412 patients, 391 (94.9%) with ischemic stroke and 21 (5.1%) with hemorrhagic stroke; 78 (18.9%) met the study criteria for pneumonia. Subjects who developed pneumonia were older (mean±SD age, 75.9±11.4 vs 64.9±13.9 years), had higher modified National Institutes of Health Stroke Scale scores, a history of chronic obstructive pulmonary disease, lower Abbreviated Mental Test scores, and a higher oral cavity score, and a greater proportion tested positive for bacterial cultures from oral swabs. In binary logistic-regression analysis, independent predictors (P<0.05) of pneumonia were age >65 years, dysarthria or no speech due to aphasia, a modified Rankin Scale score ≥4, an Abbreviated Mental Test score <8, and failure on the water swallow test. The presence of 2 or more of these risk factors carried 90.9% sensitivity and 75.6% specificity for the development of pneumonia.</p> <p><b>Conclusions:</b> Pneumonia after stroke is associated with older age, dysarthria/no speech due to aphasia, severity of poststroke disability, cognitive impairment, and an abnormal water swallow test result. Simple assessment of these variables could be used to identify patients at high risk of developing pneumonia after stroke.</p&gt
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