987 resultados para Instrument de mesure


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Diffuse reflectance spectroscopy with a fiber optic probe is a powerful tool for quantitative tissue characterization and disease diagnosis. Significant systematic errors can arise in the measured reflectance spectra and thus in the derived tissue physiological and morphological parameters due to real-time instrument fluctuations. We demonstrate a novel fiber optic probe with real-time, self-calibration capability that can be used for UV-visible diffuse reflectance spectroscopy in biological tissue in clinical settings. The probe is tested in a number of synthetic liquid phantoms over a wide range of tissue optical properties for significant variations in source intensity fluctuations caused by instrument warm up and day-to-day drift. While the accuracy for extraction of absorber concentrations is comparable to that achieved with the traditional calibration (with a reflectance standard), the accuracy for extraction of reduced scattering coefficients is significantly improved with the self-calibration probe compared to traditional calibration. This technology could be used to achieve instrument-independent diffuse reflectance spectroscopy in vivo and obviate the need for instrument warm up and post∕premeasurement calibration, thus saving up to an hour of precious clinical time.

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BACKGROUND: Anticoagulation can reduce quality of life, and different models of anticoagulation management might have different impacts on satisfaction with this component of medical care. Yet, to our knowledge, there are no scales measuring quality of life and satisfaction with anticoagulation that can be generalized across different models of anticoagulation management. We describe the development and preliminary validation of such an instrument - the Duke Anticoagulation Satisfaction Scale (DASS). METHODS: The DASS is a 25-item scale addressing the (a) negative impacts of anticoagulation (limitations, hassles and burdens); and (b) positive impacts of anticoagulation (confidence, reassurance, satisfaction). Each item has 7 possible responses. The DASS was administered to 262 patients currently receiving oral anticoagulation. Scales measuring generic quality of life, satisfaction with medical care, and tendency to provide socially desirable responses were also administered. Statistical analysis included assessment of item variability, internal consistency (Cronbach's alpha), scale structure (factor analysis), and correlations between the DASS and demographic variables, clinical characteristics, and scores on the above scales. A follow-up study of 105 additional patients assessed test-retest reliability. RESULTS: 220 subjects answered all items. Ceiling and floor effects were modest, and 25 of the 27 proposed items grouped into 2 factors (positive impacts, negative impacts, this latter factor being potentially subdivided into limitations versus hassles and burdens). Each factor had a high degree of internal consistency (Cronbach's alpha 0.78-0.91). The limitations and hassles factors consistently correlated with the SF-36 scales measuring generic quality of life, while the positive psychological impact scale correlated with age and time on anticoagulation. The intra-class correlation coefficient for test-retest reliability was 0.80. CONCLUSIONS: The DASS has demonstrated reasonable psychometric properties to date. Further validation is ongoing. To the degree that dissatisfaction with anticoagulation leads to decreased adherence, poorer INR control, and poor clinical outcomes, the DASS has the potential to help identify reasons for dissatisfaction (and positive satisfaction), and thus help to develop interventions to break this cycle. As an instrument designed to be applicable across multiple models of anticoagulation management, the DASS could be crucial in the scientific comparison between those models of care.

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En este trabajo se describe una experiencia llevada a cabo con profesores de matemáticas en formación, sobre el papel que pueden desarrollar las nuevas tecnologías para llevar a cabo procesos de demostración y prueba en el aula de secundaria.

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En este trabajo se describe detalladamente una experiencia llevada a cabo con profesores de matemáticas en formación, sobre el papel que pueden desarrollar las nuevas tecnologías para llevar a cabo procesos de demostración y prueba en el aula de secundaria.

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Das Verbundstudium der nordrhein-westfälischen Fachhochschulen bietet über 3000 Studierenden die Möglichkeit, in einer Kombination von Präsenz- und Selbststudium neben dem Beruf zu studieren. Das Institut für Verbundstudien koordiniert und organisiert die Kooperationsprozesse der Hochschulen und engagiert sich mit seinem Bereich Hochschuldidaktik und Fernstudienentwicklung als Entwicklungs- und Kompetenzzentrum im Bereich der Neuen Medien und des E-Learnings. Zur Verbreitung und Verstetigung der digitalen Lehr- und Lernangebote sowie der Optimierung der Kooperations- und Supportstrukturen hat das Institut eine Onlinebefragung von 200 Lehrenden zur Situation und den Perspektiven des E-Learnings im Verbundstudium durchgeführt. Die Studie zeigt, dass für die Lehrenden auch zukünftig die gedruckte Lerneinheit das zentrale Element der Lehre sein wird. Sie sehen Bedarf zur Ergänzung und Anreicherung des Studiums sowie des Lernens und wünschen sich zur Unterstützung der Lehre ergänzende digitale Elemente vor allem in folgenden Bereichen: Kommunikation, Ergänzungen zu Lerneinheiten (Linklisten, Übungen, ergänzende Medien und Materialien), übergreifendes Glossar. Die Ergebnisse der Onlinebefragung sind die Grundlage des von den Gremien des Verbundstudiums beschlossenen E-Learning-Konzepts. Die von den Lehrenden gewünschten digitalen Elemente und Funktionen sind im Rahmen der Entwicklung durch den Bereich Hochschuldidaktik und Fernstudienentwicklung in der E-Learning-Umgebung VS-online umgesetzt worden. Zurzeit werden die bereitgestellten Elemente und Funktionen von den einzelnen Verbundstudiengängen mit Beiträgen und Inhalten gefüllt. (DIPF/Orig.)

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A method for simulation of acoustical bores, useful in the context of sound synthesis by physical modeling of woodwind instruments, is presented. As with previously developed methods, such as digital waveguide modeling (DWM) [Smith, Comput. Music J. 16, pp 74-91 (1992)] and the multi convolution algorithm (MCA) [Martinez et al., J. Acoust. Soc. Am. 84, pp 1620-1627 (1988)], the approach is based on a one-dimensional model of wave propagation in the bore. Both the DWM method and the MCA explicitly compute the transmission and reflection of wave variables that represent actual traveling pressure waves. The method presented in this report, the wave digital modeling (WDM) method, avoids the typical limitations associated with these methods by using a more general definition of the wave variables. An efficient and spatially modular discrete-time model is constructed from the digital representations of elemental bore units such as cylindrical sections, conical sections, and toneholes. Frequency-dependent phenomena, such as boundary losses, are approximated with digital filters. The stability of a simulation of a complete acoustic bore is investigated empirically. Results of the simulation of a full clarinet show that a very good concordance with classic transmission-line theory is obtained.

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This article examines the relationship of the body with a musical instrument; specifically it looks at the vital threshold conditions that occur during the interplay of voice and instrument. By examining the work ‘IKAS’ (1982) for solo saxophone by German composer Hans-Joachim Hespos, the unusual timbral relationships created between vocal and instrumental sounds are exposed. I argue that this particular work highlights the performer/instrument relation as one marked by Gilles Deleuze’s notion of the workings of a machine and a machine’s relation to a ‘flow’, in particular a machine’s function with view to the break in the flow. By turning towards Deleuze’s concept of the machine, this article offers a slightly different vocabulary for music analysis, one that more easily encompasses certain works of the twentieth century, specifically those that are more timbre- than pitch-based.