967 research outputs found

    Ultralow-power GaAs MESFET MSI circuits using two-phase dynamic FET logic

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    Quantum-enhanced micromechanical displacement sensitivity

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    We report on a hitherto unexplored application of squeezed light: for quantum-enhancement of mechanical transduction sensitivity in microcavity optomechanics. Using a toroidal silica microcavity, we experimentally demonstrate measurement of the transduced phase modulation signal with a sensitivity 0.72(±0.01)-0.72(\pm 0.01)\,dB below the shot noise level. This is achieved for resonant probing in the highly under-coupled regime, by preparing the probe in a weak coherent state with phase squeezed vacuum states at sideband frequencies

    Atomic spectroscopy studies of short-lived isotopes and nuclear isomer separation with the ISOLDE RILIS

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    The Resonance Ionization Laser Ion Source (RILIS) at the ISOLDE on-line isotope separator is based on the selective excitation of atomic transitions by tunable laser radiation. Ion beams of isotopes of 20 elements have been produced using the RILIS setup. Together with the mass separator and a particle detection system it represents a tool for high-sensitive laser spectroscopy of short-lived isotopes. By applying narrow-bandwidth lasers for the RILIS one can study isotope shifts (IS) and hyperfine structure (HFS) of atomic optical transitions. Such measurements are capable of providing data on nuclear charge radii, spins and magnetic moments of exotic nuclides far from stability. Although the Doppler broadening of the optical absorption lines limits the resolution of the technique, the accuracy of the HFS measurements examined in experiments with stable Tl isotopes approaches a value of 100 MHz. Due to the hyperfine splitting of atomic lines the RILIS gives an opportunity to separate nuclear isomers. Isomer selectivity of the RILIS has been used in studies of short-lived Ag, Cu and Pb isotopes

    Isotope Shift Measurements of Stable and Short-Lived Lithium Isotopes for Nuclear Charge Radii Determination

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    Changes in the mean-square nuclear charge radii along the lithium isotopic chain were determined using a combination of precise isotope shift measurements and theoretical atomic structure calculations. Nuclear charge radii of light elements are of high interest due to the appearance of the nuclear halo phenomenon in this region of the nuclear chart. During the past years we have developed a new laser spectroscopic approach to determine the charge radii of lithium isotopes which combines high sensitivity, speed, and accuracy to measure the extremely small field shift of an 8 ms lifetime isotope with production rates on the order of only 10,000 atoms/s. The method was applied to all bound isotopes of lithium including the two-neutron halo isotope Li-11 at the on-line isotope separators at GSI, Darmstadt, Germany and at TRIUMF, Vancouver, Canada. We describe the laser spectroscopic method in detail, present updated and improved values from theory and experiment, and discuss the results.Comment: 34 pages, 24 figures, 14 table

    Development and External Validation of the International Early Warning Score for Improved Age- and Sex-Adjusted In-Hospital Mortality Prediction in the Emergency Department

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    Objectives: Early Warning Scores (EWSs) have a great potential to assist clinical decision-making in the emergency department (ED). However, many EWS contain methodological weaknesses in development and validation and have poor predictive performance in older patients. The aim of this study was to develop and externally validate an International Early Warning Score (IEWS) based on a recalibrated National Early warning Score (NEWS) model including age and sex and evaluate its performance independently at arrival to the ED in three age categories (18-65, 66-80, &gt; 80 yr). Design: International multicenter cohort study. Setting: Data was used from three Dutch EDs. External validation was performed in two EDs in Denmark. Patients: All consecutive ED patients greater than or equal to 18 years in the Netherlands Emergency department Evaluation Database (NEED) with at least two registered vital signs were included, resulting in 95,553 patients. For external validation, 14,809 patients were included from a Danish Multicenter Cohort (DMC). Measurements and Main Results: Model performance to predict in-hospital mortality was evaluated by discrimination, calibration curves and summary statistics, reclassification, and clinical usefulness by decision curve analysis. In-hospital mortality rate was 2.4% (n = 2,314) in the NEED and 2.5% (n = 365) in the DMC. Overall, the IEWS performed significantly better than NEWS with an area under the receiving operating characteristic of 0.89 (95% CIs, 0.89-0.90) versus 0.82 (0.82-0.83) in the NEED and 0.87 (0.85-0.88) versus 0.82 (0.80-0.84) at external validation. Calibration for NEWS predictions underestimated risk in older patients and overestimated risk in the youngest, while calibration improved for IEWS with a substantial reclassification of patients from low to high risk and a standardized net benefit of 5-15% in the relevant risk range for all age categories. Conclusions: The IEWS substantially improves in-hospital mortality prediction for all ED patients greater than or equal to18 years.</p

    Quantum coherent control of highly multipartite continuous-variable entangled states by tailoring parametric interactions

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    The generation of continuous-variable multipartite entangled states is important for several protocols of quantum information processing and communication, such as one-way quantum computation or controlled dense coding. In this article we theoretically show that multimode optical parametric oscillators can produce a great variety of such states by an appropriate control of the parametric interaction, what we accomplish by tailoring either the spatio-temporal shape of the pump, or the geometry of the nonlinear medium. Specific examples involving currently available optical parametric oscillators are given, hence showing that our ideas are within reach of present technology.Comment: 14 pages, 5 figure

    Doctor-patient interaction in Finnish primary health care as perceived by first year medical students

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    BACKGROUND: In Finland, public health care is the responsibility of primary health care centres, which render a wide range of community level preventive, curative and rehabilitative medical care. Since 1990's, medical studies have involved early familiarization of medical students with general practice from the beginning of the studies, as this pre-clinical familiarisation helps medical students understand patients as human beings, recognise the importance of the doctor-patient relationship and identify practicing general practitioners (GPs) as role models for their professional development. Focused on doctor-patient relationship, we analysed the reports of 2002 first year medical students in the University of Kuopio. The students observed GPs' work during their 2-day visit to primary health care centres. METHODS: We analysed systematically the texts of 127 written reports of 2002, which represents 95.5% of the 133 first year pre-clinical medical students reports. The reports of 2003 (N = 118) and 2004 (N = 130) were used as reference material. RESULTS: Majority of the students reported GPs as positive role models. Some students reported GPs' poor attitudes, which they, however, regarded as a learning opportunity. Students generally observed a great variety of responsibilities in general practice, and expressed admiration for the skills and abilities required. They appreciated the GPs' interest in patients concerns. GPs' communication styles were found to vary considerably. Students reported some factors disturbing the consultation session, such as the GP staring at the computer screen and other team members entering the room. Working with marginalized groups, the chronically and terminally ill, and dying patients was seen as an area for development in the busy Finnish primary health care centres. CONCLUSION: During the analysis, we discovered that medical students' perceptions in this study are in line with the previous findings about the importance of role model (good or bad) in making good doctors. Therefore, medical students' pre-clinical primary health care centre visits may influence their attitudes towards primary health care work and the doctor-patient relationship. We welcome more European studies on the role of early pre-clinical general practice exposure on medical students' primary care specialty choice
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