20 research outputs found

    Characteristic Evolution and Matching

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    I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress in characteristic evolution is traced from the early stage of 1D feasibility studies to 2D axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black hole spacetime. Cauchy codes have now been successful at simulating all aspects of the binary black hole problem inside an artificially constructed outer boundary. A prime application of characteristic evolution is to extend such simulations to null infinity where the waveform from the binary inspiral and merger can be unambiguously computed. This has now been accomplished by Cauchy-characteristic extraction, where data for the characteristic evolution is supplied by Cauchy data on an extraction worldtube inside the artificial outer boundary. The ultimate application of characteristic evolution is to eliminate the role of this outer boundary by constructing a global solution via Cauchy-characteristic matching. Progress in this direction is discussed.Comment: New version to appear in Living Reviews 2012. arXiv admin note: updated version of arXiv:gr-qc/050809

    Therapeutic suggestion helps to cut back on drug intake for mechanically ventilated patients in intensive care unit

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    Research was conducted on ventilated patients treated in an intensive care unit (ICU) under identical circumstances; patients were divided into two groups (subsequently proved statistically identical as to age and Simplified Acute Physiology Score II [SAPS II]). One group was treated with positive suggestions for 15-20 min a day based on a predetermined scheme, but tailored to the individual patient, while the control group received no auxiliary psychological treatment. Our goal was to test the effects of positive communication in this special clinical situation. In this section of the research, the subsequent data collection was aimed to reveal whether any change in drug need could be demonstrated upon the influence of suggestions as compared to the control group. Owing to the strict recruitment criteria, a relatively small sample (suggestion group n = 15, control group n = 10) was available during the approximately nine-month period of research. As an outcome of suggestions, there was a significant drop in benzodiazepine (p < 0.005), opioid (p < 0.001), and the α2-agonist (p < 0.05) intake. All this justifies the presence of therapeutic suggestions among the therapies used in ICUs. However, repeating the trial on a larger sample of patients would be recommended. © 2013 Akadémiai Kiadó, Budapest

    Preventing the next 'SARS' - European healthcare workers' attitudes towards monitoring their health for the surveillance of newly emerging infections: qualitative study

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    <p>Abstract</p> <p>Background</p> <p>Hospitals are often the epicentres of newly circulating infections. Healthcare workers (HCWs) are at high risk of acquiring infectious diseases and may be among the first to contract emerging infections. This study aims to explore European HCWs' perceptions and attitudes towards monitoring their absence and symptom reports for surveillance of newly circulating infections.</p> <p>Methods</p> <p>A qualitative study with thematic analysis was conducted using focus group methodology. Forty-nine hospital-based HCWs from 12 hospitals were recruited to six focus groups; two each in England and Hungary and one each in Germany and Greece.</p> <p>Results</p> <p>HCWs perceived risk factors for occupationally acquired infectious diseases to be 1.) exposure to patients with undiagnosed infections 2.) break-down in infection control procedures 3.) immuno-naïvety and 4.) symptomatic colleagues. They were concerned that a lack of monitoring and guidelines for infectious HCWs posed a risk to staff and patients and felt employers failed to take a positive interest in their health. Staffing demands and loss of income were noted as pressures to attend work when unwell. In the UK, Hungary and Greece participants felt monitoring staff absence and the routine disclosure of symptoms could be appropriate provided the effectiveness and efficiency of such a system were demonstrable. In Germany, legislation, privacy and confidentiality were identified as barriers.</p> <p>All HCWs highlighted the need for knowledge and structural improvements for timelier recognition of emerging infections. These included increased suspicion and awareness among staff and standardised, homogenous absence reporting systems.</p> <p>Conclusions</p> <p>Monitoring absence and infectious disease symptom reports among HCWs may be a feasible means of surveillance for emerging infections in some settings. A pre-requisite will be tackling the drivers for symptomatic HCWs to attend work.</p

    Characteristic Evolution and Matching

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    I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress is traced from the early stage of 1D feasibility studies to 2D axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black spacetime. A prime application of characteristic evolution is to compute waveforms via Cauchy-characteristic matching, which is also reviewed.Comment: Published version http://www.livingreviews.org/lrr-2005-1
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