1,712 research outputs found

    Guided sparse camera pose estimation

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    In this paper, we present an idea for a sparse approach to calculate camera poses from RGB images and laser distance measurements to perform subsequent facade reconstruction. The core idea is to guide the image recording process by choosing distinctive features with the laser range finder, e.g. building or window corners. From these distinctive features, we can establish correspondences between views to compute metrically accurate camera poses from just a few precise measurements. In our experiments, we achieve reasonable results in building facade reconstruction with only a fraction of features compared to standard structure from motion

    Arbeitsmarkt 2030 - Arbeitskräftebedarf kleinerer, mittlerer und großer Betriebe: eine strategische Vorausschau auf den Fachkräftebedarf nach Betriebsgröße

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    Der Bericht führt die Überlegungen der Publikation "Arbeitsmarkt 2030 - Eine strategische Vorausschau auf Demografie, Beschäftigung und Bildung in Deutschland" durch eine Differenzierung nach Betriebsgröße fort. Die Autoren gehen zwei Hauptfragen nach: Wie wird sich der sektorale, berufliche und qualifikationsspezifische Strukturwandel in der Nachfrage nach Arbeitskräften der Betriebe unterschiedlicher Größe niederschlagen? Und wie werden sich die verschieden großen Betriebe im Wettbewerb um Arbeitskräfte behaupten

    Selective arterialization of a cardiac vein in a model of cardiac microangiopathy and macroangiopathy in sheep

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    ObjectiveSome patients with significant arteriosclerosis of the heart are not amenable to revascularization of a coronary artery because they have a combination of microangiopathy and significant macroangiopathy. We investigated the benefit of arterialization of a cardiac vein under these circumstances in an acute animal model.MethodsIn the hearts of 8 sheep, microspheres were injected into the left coronary artery; 60 minutes later, a stenosis of the left anterior descending artery was performed. After 45 minutes, retrograde venous revascularization was performed by sewing the left internal thoracic artery to the concomitant vein of the left anterior descending artery in a beating-heart technique. For flow reversal, the vein was ligated proximally to the anastomosis. The efficiency of the bypass graft was evaluated by coronary angiography and flow measurement. Cardiac output, electrocardiography, and mean arterial blood pressure were assessed in each phase of the experiment.ResultsThe ischemic state of the myocardium was confirmed by a significant decrease of cardiac output, stroke volume, and mean arterial blood pressure, and a significant elevation of the ST segment in the electrocardiography. After retrograde venous revascularization was established, cardiac output and stroke volume increased and ST elevations decreased. The grafts showed adequate flow (26.15 ± 2.08 mL/min), and reversed blood flow in the grafted vein was proved by coronary angiography.ConclusionRetrograde venous revascularization is possible and improves cardiac function in a state of acute ischemia caused by a combination of microangiopathy and macroangiopathy

    Talbot-Lau x-ray phase-contrast setup for fast scanning of large samples

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    Abstract Compared to conventional attenuation x-ray radiographic imaging, the x-ray Talbot-Lau technique provides further information about the scattering and the refractive properties of the object in the beam path. Hence, this additional information should improve the diagnostic process concerning medical applications and non-destructive testing. Nevertheless, until now, due to grating fabrication process, Talbot-Lau imaging suffers from small grating sizes (70 mm diameter). This leads to long acquisition times for imaging large objects. Stitching the gratings is one solution. Another one consists of scanning Talbot-Lau setups. In this publication, we present a compact and very fast scanning setup which enables imaging of large samples. With this setup a maximal scanning velocity of 71.7 mm/s is possible. A resolution of 4.1 lines/mm can be achieved. No complex alignment procedures are necessary while the field of view comprises 17.5 × 150 cm2. An improved reconstruction algorithm concerning the scanning approach, which increases robustness with respect to mechanical instabilities, has been developed and is presented. The resolution of the setup in dependence of the scanning velocity is evaluated. The setup imaging qualities are demonstrated using a human knee ex-vivo as an example for a high absorbing human sample

    Nucleosynthetic osmium isotope anomalies in acid leachates of the Murchison meteorite

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    We present osmium isotopic results obtained by sequential leaching of the Murchison meteorite, which reveal the existence of very large internal anomalies of nucleosynthetic origin. The Os isotopic anomalies are correlated, and can be explained by the variable contributions of components derived from the s, r and p-processes of nucleosynthesis. Much of the s-process rich osmium is released by relatively mild leaching, suggesting the existence of an easily leachable s-process rich presolar phase, or alternatively, of a chemically resistant r-process rich phase. The s-process composition of Os released by mild leaching diverges slightly from that released by aggressive digestion techniques, perhaps suggesting that the presolar phases attacked by these differing procedures condensed in different stellar environments. The correlation between 190Os and 188Os can be used to constrain the s-process 190Os/188Os ratio to be 1.275 pm 0.043. Such a ratio can be reproduced in a nuclear reaction network for a MACS value for 190Os of ~200 pm 22 mbarn at 30 keV. We also present evidence for extensive internal variation of 184Os abundances in the Murchison meteorite. This suggests that p process rich presolar grains (e.g., supernova condensates) may be present in meteorites in sufficient quantities to influence the Os isotopic compositions of the leachates.Comment: 40 pages, 9 figures, 2 tables. Accepted for publication in Earth and Planetary Science Letter

    RNA binding protein Caprin-2 is a pivotal regulator of the central osmotic defense response

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    In response to an osmotic challenge, the synthesis of the antidiuretic hormone arginine vasopressin (AVP) increases in the hypothalamus, and this is accompanied by extension of the 3′ poly(A) tail of the AVP mRNA, and the up-regulation of the expression of RNA binding protein Caprin-2. Here we show that Caprin-2 binds to AVP mRNAs, and that lentiviral mediated shRNA knockdown of Caprin-2 in the osmotically stimulated hypothalamus shortens the AVP mRNA poly(A) tail at the same time as reducing transcript abundance. In a recapitulated in vitro system, we confirm that Caprin-2 over-expression enhances AVP mRNA abundance and poly(A) tail length. Importantly, we show that Caprin-2 knockdown in the hypothalamus decreases urine output and fluid intake, and increases urine osmolality, urine sodium concentration, and plasma AVP levels. Thus Caprin-2 controls physiological mechanisms that are essential for the body's response to osmotic stress. DOI: http://dx.doi.org/10.7554/eLife.09656.00

    Transcatheter valve implantation for patients with aortic stenosis: a position statement from the European Association of Cardio-Thoracic Surgery (EACTS) and the European Society of Cardiology (ESC), in collaboration with the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

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    Aims: To critically review the available transcatheter aortic valve implantation techniques and their results, as well as propose recommendations for their use and development. Methods and results: A committee of experts including European Association of Cardio-Thoracic Surgery and European Society of Cardiology representatives met to reach a consensus based on the analysis of the available data obtained with transcatheter aortic valve implantation and their own experience. The evidence suggests that this technique is feasible and provides haemodynamic and clinical improvement for up to 2 years in patients with severe symptomatic aortic stenosis at high risk or with contraindications for surgery. Questions remain mainly concerning safety and long-term durability, which have to be assessed. Surgeons and cardiologists working as a team should select candidates, perform the procedure, and assess the results. Today, the use of this technique should be restricted to high-risk patients or those with contraindications for surgery. However, this may be extended to lower risk patients if the initial promise holds to be true after careful evaluation. Conclusion: Transcatheter aortic valve implantation is a promising technique, which may offer an alternative to conventional surgery for high-risk patients with aortic stenosis. Today, careful evaluation is needed to avoid the risk of uncontrolled diffusio

    Measurement of the running of the QED coupling in small-angle Bhabha scattering at LEP

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    Using the OPAL detector at LEP, the running of the effective QED coupling alpha(t) is measured for space-like momentum transfer from the angular distribution of small-angle Bhabha scattering. In an almost ideal QED framework, with very favourable experimental conditions, we obtain: Delta alpha(-6.07GeV^2) - Delta alpha(-1.81GeV^2) = (440 pm 58 pm 43 pm 30) X 10^-5, where the first error is statistical, the second is the experimental systematic and the third is the theoretical uncertainty. This agrees with current evaluations of alpha(t).The null hypothesis that alpha remains constant within the above interval of -t is excluded with a significance above 5sigma. Similarly, our results are inconsistent at the level of 3sigma with the hypothesis that only leptonic loops contribute to the running. This is currently the most significant direct measurment where the running alpha(t) is probed differentially within the measured t range.Comment: 43 pages, 12 figures, Submitted to Euro. Phys. J.
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