1,398 research outputs found

    Broad levels in 17^{17}O and their relevance for the astrophysical s-process

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    Levels in 17^{17}O affect the astrophysical s-process in two opposite ways. The neutron production is enhanced by resonances in the 13^{13}C(α\alpha,nn)16^{16}O reaction at excitation energies around 7 MeV in 17^{17}O, and the number of available neutrons is reduced by low-lying resonances in the 16^{16}O(nn,γ\gamma)17^{17}O reaction corresponding to levels in 17^{17}O with excitation energies of 454-5 MeV. The present work uses the 19^{19}F(dd,α\alpha)17^{17}O reaction to determine absolute widths of the relevant levels in 17^{17}O. The results improve the uncertainties of the previously adopted values and resolve a discrepancy between recent studies for the 1/2+1/2^+ level close to the threshold of the 13^{13}C(α\alpha,nn)16^{16}O reaction. In addition, improved excitation energies and widths are provided for several states in 17^{17}O up to excitation energies close to 8 MeV.Comment: 5 pages, 2 figures, Phys. Rev. C (in press

    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

    Inverse relationship between tumor proliferation markers and connexin expression in a malignant cardiac tumor originating from mesenchymal stem cell engineered tissue in a rat in vivo model

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    Recently, we demonstrated the beneficial effects of engineered heart tissues for the treatment of dilated cardiomyopathy in rats. For further development of this technique we started to produce engineered tissue (ET) from mesenchymal stem cells. Interestingly, we observed a malignant tumor invading the heart with an inverse relationship between proliferation markers and connexin expression

    Time resolved X-ray Dark-Field Tomography Revealing Water Transport in a Fresh Cement Sample

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    Grating-based X-ray dark-field tomography is a promising technique for biomedical and materials research. Even if the resolution of conventional X-ray tomography does not suffice to resolve relevant structures, the dark-field signal provides valuable information about the sub-pixel microstructural properties of the sample. Here, we report on the potential of X-ray dark-field imaging to be used for time-resolved three-dimensional studies. By repeating consecutive tomography scans on a fresh cement sample, we were able to study the hardening dynamics of the cement paste in three dimensions over time. The hardening of the cement was accompanied by a strong decrease in the dark-field signal pointing to microstructural changes within the cement paste. Furthermore our results hint at the transport of water from certain limestone grains, which were embedded in the sample, to the cement paste during the process of hardening. This is indicated by an increasing scattering signal which was observed for two of the six tested limestone grains. Electron microscopy images revealed a distinct porous structure only for those two grains which supports the following interpretation of our results. When the water filled pores of the limestone grains empty during the experiment the scattering signal of the grains increases

    Staged Concept for Treatment of Severe Postsaphenectomy Wound Infection

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    The saphenous vein remains the most commonly used conduit in coronary artery bypass surgery. Vein harvest is a critical component with significant morbidity associated with leg wounds from open technique. Occurring complications are hematoma, postoperative pain, skin changes, neuropathy, and septic or nonseptic wound complications. Within the context of a recent case, we present our approach to postsaphenectomy wound management

    Constraints on Cosmological Parameters from Future Galaxy Cluster Surveys

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    We study the expected redshift evolution of galaxy cluster abundance between 0 < z < 3 in different cosmologies, including the effects of the cosmic equation of state parameter w=p/rho. Using the halo mass function obtained in recent large scale numerical simulations, we model the expected cluster yields in a 12 deg^2 Sunyaev-Zeldovich Effect (SZE) survey and a deep 10^4 deg^2 X-ray survey over a wide range of cosmological parameters. We quantify the statistical differences among cosmologies using both the total number and redshift distribution of clusters. Provided that the local cluster abundance is known to a few percent accuracy, we find only mild degeneracies between w and either Omega_m or h. As a result, both surveys will provide improved constraints on Omega_m and w. The Omega_m-w degeneracy from both surveys is complementary to those found either in studies of CMB anisotropies or of high-redshift Supernovae (SNe). As a result, combining these surveys together with either CMB or SNe studies can reduce the statistical uncertainty on both w and Omega_m to levels below what could be obtained by combining only the latter two data sets. Our results indicate a formal statistical uncertainty of about 3% (68% confidence) on both Omega_m and w when the SZE survey is combined with either the CMB or SN data; the large number of clusters in the X-ray survey further suppresses the degeneracy between w and both Omega_m and h. Systematics and internal evolution of cluster structure at the present pose uncertainties above these levels. We briefly discuss and quantify the relevant systematic errors. By focusing on clusters with measured temperatures in the X-ray survey, we reduce our sensitivity to systematics such as non-standard evolution of internal cluster structure.Comment: ApJ, revised version. Expanded discussion of systematics; Press-Schechter mass function replaced by fit from simulation

    Information technology in management personnel on the example of KC "Jobs"

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    Analysis of the workings and personnel decisions in the field of human resource management. They are inextricably linked to the processes of information processing. The higher the effect of the use of personnel information, the more objective decisions will be made by the heads of a wide variety of human resources issues. In this regard, there is a need in the compilation and dissemination of the experience gained in the application of modern technologies, as well the creation of new software products. Consideration of "human process management" module. It is designed to automate the management processes in terms of the conduct of personnel information in the context of positions and employees in order to provide the head of information for management decision making and carrying out related activities. Consideration of the positive and negative sides of the module, as its distinctivefeatures

    Surgical Therapy of Atrial Fibrillation

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    Atrial fibrillation (AF) can be found in an increasing number of cardiac surgical patients due to a higher patient's age and comorbidities. Atrial fibrillation is known, however, to be a risk factor for a greater mortality, and one aim of intraoperative AF treatment is to approximate early and long-term survival of AF patients to survival of patients with preoperative sinus rhythm. Today, surgeons are more and more able to perform less complex, that is, minimally invasive cardiac surgical procedures. The evolution of alternative ablation technologies using different energy sources has revolutionized the surgical therapy of atrial fibrillation and allows adding the ablation therapy without adding significant risk. Thus, the surgical treatment of atrial fibrillation in combination with the cardiac surgery procedure allows to improve the postoperative long-term survival and to reduce permanent anticoagulation in these patients. This paper focuses on the variety of incisions, lesion sets, and surgical techniques, as well as energy modalities and results of AF ablation and also summarizes future trends and current devices in use
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