2,231 research outputs found

    Pulmonary and cardiac drugs: clinically relevant interactions

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    Chronic heart and lung diseases are very common in the elderly population. The combination of chronic heart failure and chronic obstructive pulmonary disease (COPD) is also common and, according to current guidelines, these patients should be treated for both diseases. In patients with heart failure, beta-blockers are very important drugs because their use is associated with significantly improved morbidity and mortality. These beneficial effects were documented in patients with and without COPD, although theoretically there is a risk for bronchoconstriction, particularly with non-beta1 selective blockers. In COPD patients, long-acting sympathomimetics (LABA) improve lung function, dyspnea, and quality of life and their combination with a beta-blocker makes sense from a pharmacological and a clinical point of view, because any potential arrhythmogenic effects of the LABA will be ameliorated by the beta-blocker. Inhaled tiotropium, a long-acting muscarinic antagonist (LAMA), has been extensively investigated and no safety concerns were reported in terms of cardiac adverse effects. The same applies for the other approved LAMA preparations and LAMA-LABA combinations. Severe COPD causes air-trapping with increasing pressures in the thorax, leading to limitations in blood return into the thorax from the periphery of the body. This causes a decrease in stroke volume and cardiac index and is associated with dyspnea. All these adverse effects can be ameliorated by potent anti-obstructive therapy as recently shown by means of a LABA-LAMA combination

    Pulmonary Vascular Tree Segmentation from Contrast-Enhanced CT Images

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    We present a pulmonary vessel segmentation algorithm, which is fast, fully automatic and robust. It uses a coarse segmentation of the airway tree and a left and right lung labeled volume to restrict a vessel enhancement filter, based on an offset medialness function, to the lungs. We show the application of our algorithm on contrast-enhanced CT images, where we derive a clinical parameter to detect pulmonary hypertension (PH) in patients. Results on a dataset of 24 patients show that quantitative indices derived from the segmentation are applicable to distinguish patients with and without PH. Further work-in-progress results are shown on the VESSEL12 challenge dataset, which is composed of non-contrast-enhanced scans, where we range in the midfield of participating contestants.Comment: Part of the OAGM/AAPR 2013 proceedings (1304.1876

    An agent-based model of wood markets: Scenario analysis

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    We present an agent-based model of wood markets. The model covers softwood and hardwood markets for sawlogs, energy wood, and industrial wood. Our study region is a mountainous area in Switzerland that is close to the border, and therefore partially depends on the wood markets of the adjacent countries. The wood markets in this study region are characterized by many small-scale wood suppliers, and a mix of private and publicowned forests. The model was developed to investigate the availability of wood in the study region under different market conditions. We defined several scenarios that are relevant to policy makers and analyzed them with a focus on the two most important assortments of wood in the study region, namely, sawlogs softwood and energy wood softwood. The development of the prices and amounts sold in the scenarios are compared to a business-as-usual scenario. The scenarios were designed to investigate i) the influence of intermediaries, ii) the influence of the profit-orientation of forest owners, iii) the influence of the exchange rate, and iv) the consequences of set-asides in the study region. The presented model has a large potential to support the planning of policy measures as it allows capturing emergent phenomena, and thereby facilitates identifying potential consequences of policy measures planned prior to their implementation. This was demonstrated by discussing the scenario findings with respect to Switzerland's forestry policy objective of increasing the harvested amount of wood to the sustainable potential. We showed that a higher profit-orientation of forest owners would be beneficial for this objective, but also revealed potential conflicts of different economic goals

    Radiometric calibration of the in-flight blackbody calibration system of the GLORIA interferometer

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    GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) is an airborne, imaging, infrared Fourier transform spectrometer that applies the limb-imaging technique to perform trace gas and temperature measurements in the Earth's atmosphere with three-dimensional resolution. To ensure the traceability of these measurements to the International Temperature Scale and thereby to an absolute radiance scale, GLORIA carries an on-board calibration system. Basically, it consists of two identical large-area and high-emissivity infrared radiators, which can be continuously and independently operated at two adjustable temperatures in a range from −50 °C to 0 °C during flight. Here we describe the radiometric and thermometric characterization and calibration of the in-flight calibration system at the Reduced Background Calibration Facility of the Physikalisch-Technische Bundesanstalt. This was performed with a standard uncertainty of less than 110 mK. Extensive investigations of the system concerning its absolute radiation temperature and spectral radiance, its temperature homogeneity and its short- and long-term stability are discussed. The traceability chain of these measurements is presented

    A Fast Algorithm Finding the Shortest Reset Words

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    In this paper we present a new fast algorithm finding minimal reset words for finite synchronizing automata. The problem is know to be computationally hard, and our algorithm is exponential. Yet, it is faster than the algorithms used so far and it works well in practice. The main idea is to use a bidirectional BFS and radix (Patricia) tries to store and compare resulted subsets. We give both theoretical and practical arguments showing that the branching factor is reduced efficiently. As a practical test we perform an experimental study of the length of the shortest reset word for random automata with nn states and 2 input letters. We follow Skvorsov and Tipikin, who have performed such a study using a SAT solver and considering automata up to n=100n=100 states. With our algorithm we are able to consider much larger sample of automata with up to n=300n=300 states. In particular, we obtain a new more precise estimation of the expected length of the shortest reset word 2.5n5\approx 2.5\sqrt{n-5}.Comment: COCOON 2013. The final publication is available at http://link.springer.com/chapter/10.1007%2F978-3-642-38768-5_1
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