425 research outputs found

    Maintaining Quantum Coherence in the Presence of Noise through State Monitoring

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    Unsharp POVM measurements allow the estimation and tracking of quantum wavefunctions in real-time with minimal disruption of the dynamics. Here we demonstrate that high fidelity state monitoring, and hence quantum control, is possible even in the presence of classical dephasing and amplitude noise, by simulating such measurements on a two-level system undergoing Rabi oscillations. Finite estimation fidelity is found to persist indefinitely long after the decoherence times set by the noise fields in the absence of measurement.Comment: 5 pages, 4 figure

    Maxillofacial Radiology 196

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    A healthy,12-year-old female patient, presented with an anterior open bite requesting orthodontic treatment. A panoramic radiograph was requested for treatment planning (Figure 1). An incidental finding of well-defined multilocular radiolucencies were detected superimposed over the right ramus and middle cranial fossa region. The patient was asymptomatic with no clinical signs of facial asymmetry. A cone-beam computerised tomography (CBCT) scan was requested to exclude any occult pathology (Figure 2)

    A Survey of the quality of nursing care in several health districts in South Africa.

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    BACKGROUND: South Africa is currently focusing strongly on human resource development. The purpose of this study was to describe and compare the quality of nursing service and care in three health districts in the KwaZulu Natal Province. To identify deficiencies which could be addressed by education and training, it might be useful to measure the quality of care given by nurses. METHODS: From March to August 2002 a survey was done in six hospitals and six clinics in three health districts of the KwaZulu-Natal province of South Africa. Five different aspects of care was evaluated; hand-over from one nursing shift to another, implementation of universal precautions, patient satisfaction, nursing records, management of chronic illnesses. All these aspects were evaluated using checklists based on record reviews or direct observation, except for patient satisfaction, which was evaluated by questionnaires. RESULTS: The average scores on the different aspects varied from 11% (for nursing records) to 73% (for management of chronic diseases). Specific problems became evident. In one district three out of four hand-overs between shifts of nurses scored less than 50%. In all three districts the use of protective gear scored low (43%). While the average score for management of chronic illnesses were high at 73%, the blood pressures of only 23% was within the target range, and the blood sugar of only 38% of patients were controlled. Patient satisfaction averaged 72% across the three districts. CONCLUSION: The quality of care measurements identified specific training needs, but other management strategies are probably also indicated

    Case Study: Cancrum oris (noma) in a malnourished HIV-positive child from rural Kwazulu-Natal

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    Cancrum oris (noma – derived from the Greek nomein, ‘to devour\') is an infectious disease with a fulminating course that destroys the oro-facial tissues and other neighbouring structures.1 Although cancrum oris can occur at any age, it is most commonly in malnourished children between the ages of 1 and 5 years whose general health has been further weakened by some infectious disease, usually measles but also tuberculosis, gastro-enteritis, typhoid, whooping cough, or malignant disease such as leukaemia. The possible relevance to HIV has not been fully investigated. This report details a case presenting to East Griqualand and Usher Memorial Hospital, Kokstad, KwaZulu-Natal. Southern African Journal of HIV Medicine Vol. 5 (3) 2004: 45-4

    Intra-osseous synovial sarcoma.

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    Intra-osseous synovial sarcoma is very rare and its mode of origin is conjectural. Our patient's tumour was situated within the lower femur. The sited of origin of the few intra-osseous synovial sarcomas so far documented may support the concept of intra-osseous synovial rests

    Decoherence due to elastic Rayleigh scattering

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    We present theoretical and experimental studies of the decoherence of hyperfine ground-state superpositions due to elastic Rayleigh scattering of light off-resonant with higher lying excited states. We demonstrate that under appropriate conditions, elastic Rayleigh scattering can be the dominant source of decoherence, contrary to previous discussions in the literature. We show that the elastic-scattering decoherence rate of a two-level system is given by the square of the difference between the elastic-scattering \textit{amplitudes} for the two levels, and that for certain detunings of the light, the amplitudes can interfere constructively even when the elastic scattering \textit{rates} from the two levels are equal. We confirm this prediction through calculations and measurements of the total decoherence rate for a superposition of the valence electron spin levels in the ground state of 9^9Be+^+ in a 4.5 T magnetic field.Comment: 5 pages, 3 figure

    Introducing a new cadre into Uganda’s health care system: lessons learnt from the implementation process

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    Uganda introduced Registered Comprehensive Nursing (RCN) and Enrolled Comprehensive Nursing (ECN) training programs in 1994 and 2003 respectively, to create certificate and diploma level cadre of nurses with competencies in general nursing, midwifery, public health, psychiatry, paediatrics and management. This paper is based on an evaluation study undertaken to assess how the programs were implemented including stakeholders’ perceptions about the graduates. Despite being relevant, the implementation process of both programs failed to meet acceptable standards. We conclude that introducing a new cadre of nurses without proper preparation hinders realization of their full potential including their contribution to the healthcare system

    Results from South Africa's 2016 report card on physical activity for children and youth

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    Background: We present results of the 2016 Healthy Active Kids South Africa (HAKSA) Report Card on the current status of physical activity (PA) and nutrition in South African youth. The context in which we interpret the findings is that participation in PA is a fundamental human right, along with the right to "attainment of the highest standard of health." Methods: The HAKSA 2016 Writing Group was comprised of 33 authorities in physical education, exercise science, nutrition, public health, and journalism. The search strategy was based on peer-reviewed manuscripts, dissertations, and 'gray' literature. The core PA indicators are Overall Physical Activity Level; Organized Sport Participation; Active and Outdoor Play; Active Transportation; Sedentary Behaviors; Family and Peer Influences; School; Community and the Built Environment; and National Government Policy, Strategies, and Investment. In addition, we reported on Physical Fitness and Motor Proficiency separately. We also reported on nutrition indicators including Overweight and Under-nutrition along with certain key behaviors such as Fruit and Vegetable Intake, and policies and programs including School Nutrition Programs and Tuck Shops. Data were extracted and grades assigned after consensus was reached. Grades were assigned to each indicator ranging from an A, succeeding with a large majority of children and youth (81% to 100%); B, succeeding with well over half of children and youth (61% to 80%); C, succeeding with about half of children and youth (41% to 60%); D, succeeding with less than half but some children and youth (21% to 40%); and F, succeeding with very few children and youth (0% to 20%); INC is inconclusive. Results: Overall PA levels received a C grade, as we are succeeding with more than 50% of children meeting recommendations. Organized Sports Participation also received a C, and Government Policies remain promising, receiving a B. Screen time and sedentary behavior were a major concern. Under-and over-weight were highlighted and, as overweight is on the rise, received a D grade. Conclusion: In particular, issues of food security, obesogenic environments, and access to activity-supportive environments should guide social mobilization downstream and policy upstream. There is an urgent need for practice-based evidence based on evaluation of existing, scaled up interventions.Scopu

    Trapped-ion probing of light-induced charging effects on dielectrics

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    We use a string of confined 40^{40}Ca+^+ ions to measure perturbations to a trapping potential which are caused by light-induced charging of an anti-reflection coated window and of insulating patches on the ion-trap electrodes. The electric fields induced at the ions' position are characterised as a function of distance to the dielectric, and as a function of the incident optical power and wavelength. The measurement of the ion-string position is sensitive to as few as 4040 elementary charges per Hz\sqrt{\mathrm{Hz}} on the dielectric at distances of order millimetres, and perturbations are observed for illumination with light of wavelengths as long as 729\,nm. This has important implications for the future of miniaturised ion-trap experiments, notably with regards to the choice of electrode material, and the optics that must be integrated in the vicinity of the ion. The method presented can be readily applied to the investigation of charging effects beyond the context of ion trap experiments.Comment: 11 pages, 5 figure
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