1,084 research outputs found

    Comment on the Shiner-Davison-Landsberg Measure

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    The complexity measure from Shiner et al. [Physical Review E 59, 1999, 1459-1464] (henceforth abbreviated as SDL-measure) has recently been the subject of a fierce debate. We discuss the properties and shortcomings of this measure, from the point of view of our recently constructed fundamental, statistical mechanics-based measures of complexity Cs(γ,β) [Stoop et al., J. Stat. Phys. 114, 2004, 1127-1137]. We show explicitly, what the shortcomings of the SDL-measure are: It is over-universal, and the implemented temperature dependence is trivial. We also show how the original SDL-approach can be modified to rule out these points of critique. Results of this modification are shown for the logistic parabol

    Quality assurance of radiodiagnostic equipment -Overview of literature since 2004

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    Het Britse handboek voor de kwaliteitsborging (Quality Assurance) van CT-scanners en andere rontgentoestellen, kan met enkele aanpassingen ook in Nederland gebruikt worden. Dit blijkt uit een literatuurstudie van het RIVM naar de kwaliteitsborging van deze apparaten. Beelden van CT-scanners en andere rontgentoestellen moeten goed genoeg zijn om een juiste diagnose te kunnen stellen. Ze worden gemaakt met rontgenstraling en die is schadelijk voor de gezondheid. De beelden worden echter vaak beter als er meer straling wordt gebruikt. Om goede beelden te krijgen met een zo laag mogelijke stralingsdosis is er veel aandacht nodig voor het optimaal laten functioneren van de apparatuur. Het geheel van maatregelen die hieraan bijdragen wordt kwaliteitsborging genoemd. Er is in Nederland geen algemeen handboek voor de kwaliteitsborging van CT-scanners en andere rontgenapparaten. Uit het onderzoek van het RIVM blijkt dat het Britse handboek, aangevuld met enkele andere documenten, vrij eenvoudig naar de Nederlandse praktijk vertaald kan worden. Wel is er nog een enkele toevoeging nodig en moeten grenswaarden worden aangepast aan de Nederlandse regelgeving.The British handbook on quality assurance of CT and other x-ray equipment may, with some adaptations, also be used in the Netherlands. This is the main conclusion of a literature study by RIVM on quality assurance of such equipment. Images from CT scanners and other x-ray equipment must have sufficient quality to enable a correct diagnosis. They are obtained using x-rays, which have adverse health effects. However, in diagnostic imaging, higher x-ray doses often lead to better image quality. To obtain good images while keeping the radiation dose as low as reasonably achievable, much attention is needed for the optimal performance of the equipment. Quality assurance is the complex of all measures needed to achieve this. A general handbook on quality assurance of CT and other x-ray equipment adapted to the Dutch practice does not exist. The literature study by RIVM shows that it should be relatively straightforward to adapt, with some additions, the British handbook to the Dutch practice and legislation.Inspectie voor de Gezondheidszor

    Quality assurance for the optimization of patient dose in interventional radiology

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    Drie maatregelen kunnen de dosis straling optimaliseren die patienten ontvangen tijdens radiologische interventies. Ten eerste moderne apparatuur gebruiken die speciaal geschikt is voor interventies. Ten tweede extra aandacht schenken aan stralingsbescherming tijdens opleidingen op het gebied van de interventieradiologie. En tot slot complicaties van straling opnemen in het complicatieregister van de sectie Interventieradiologie van de Nederlandse Vereniging voor Radiologie. Dit blijkt uit onderzoek dat het RIVM in opdracht van de Inspectie voor de Gezondheidszorg heeft uitgevoerd naar de kwaliteitsborging van de interventieradiologie in Nederland. De opdracht is ingegeven door de relatief hoge stralingsdosis waaraan patienten kunnen worden blootgesteld tijdens radiologische interventies. Bij interventieradiologie worden medische behandelingen uitgevoerd via een kleine opening in de huid, terwijl die ingreep in beeld wordt gebracht met behulp van rontgen, CT, MRI of echografie. Bij gebruik van rontgen of CT kan de stralingsdosis leiden tot nadelige effecten voor de gezondheid, zoals roodheid, verbranding van de huid, (tijdelijke) ontharing of op de lange termijn kanker.Three measures may optimize the radiation dose that patients receive during interventional radiology procedures. The first is by using modern equipment that is appropriate for interventional radiology procedures, while the second involves paying extra attention to radiation protection in courses in the field of interventional radiology. A final measure is to incorporate radiation-related complications into the complication register of the Interventional Radiology section of the Dutch Association for Radiology. This was found in an investigation of quality assurance in interventional radiology in the Netherlands that was assigned to RIVM by the Dutch Health Inspectorate. The investigation was motivated by the relatively high radiation dose that patients undergoing an interventional radiology procedure may be exposed to. In interventional radiology, medical treatment is applied through a small opening in the skin, while the procedure is monitored using medical imaging such as X-ray, CT, MRI or ultrasound. In the case of X-ray or CT, the radiation dose may cause adverse health effects such as erythema, burnt skin, (temporary) epilation or, in the long term, cancer.Inspectie voor de Gezondheidszor

    Мои воспоминания об Иване Георгиевиче Спасском

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    Стислі спогади автора про відомого вченого-нумізмата й музейника І.Г. Спаського та його сім’ю.Краткие воспоминания автора об известном ученом-нумизмате и музейщике И.Г. Спасском и его семье.Short author’s memories about known scientist-numismatist and museum-worker I.G. Spassky and his family

    Disease management for co-morbid depression and anxiety in diabetes mellitus: design of a randomised controlled trial in primary care

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    BACKGROUND: Depression and anxiety are common co-morbid health problems in patients with type 2 diabetes. Both depression and anxiety are associated with poor glycaemic control and increased risk of poor vascular outcomes and higher mortality rates. Results of previous studies have shown that in clinical practice, treatment of depression and anxiety is far from optimal as these symptoms are frequently overlooked and undertreated. METHODS/DESIGN: This randomised controlled trial will examine the effectiveness of a disease management programme treating symptoms of depression and anxiety in primary care patients with Type 2 diabetes. Patients will be randomized on patient level in 1:1 ratio. Random block sizes of 2 and 4 are used. The disease management programme consists of screening, stepped treatment and monitoring of symptoms (n = 80). This will be compared to care as usual (n = 80). DISCUSSION: The disease management model for co-morbid depression and anxiety in primary care patients with diabetes is expected to result in reduced symptoms of depression and anxiety, improved quality of life, reduced diabetes specific distress and improved glyceamic control, compared to care as usual. TRIAL REGISTRATION: Dutch Trial Register NTR262

    Collective directional locking of colloidal monolayers on a periodic substrate

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    We investigate the directional locking effects that arise when a monolayer of paramagnetic colloidal particles is driven across a triangular lattice of magnetic bubbles. We use an external rotating magnetic field to generate a two-dimensional traveling wave ratchet forcing the transport of particles along a direction that intersects two crystallographic axes of the lattice. We find that, while single particles show no preferred direction, collective effects induce transversal current and directional locking at high density via a spontaneous symmetry breaking. The colloidal current may be polarized via an additional bias field that makes one transport direction energetically preferred
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