719 research outputs found
Towards 10 cm/s radial velocity accuracy on the Sun using a Fourier transform spectrometer
No full textThe IAG solar observatory is producing high-fidelity, ultra-high-resolution
spectra (R>500000) of the spatially resolved surface of the Sun using a Fourier
Transform spectrometer (FTS). The radial velocity (RV) calibration of these
spectra is currently performed using absorption lines from Earth's atmosphere,
limiting the precision and accuracy. To improve the frequency calibration
precision and accuracy we plan to use a Fabry-Perot etalon (FP) setup that is
an evolution of the CARMENES FP design and an iodine cell in combination. To
create an accurate wavelength solution, the iodine cell is measured in parallel
with the FP. The FP can then be used to transfer the accurate wavelength
solution provided by the iodine via simultaneous calibration of solar
observations. To verify the stability and precision of the FTS we perform
parallel measurements of the FP and an iodine cell. The measurements show an
intrinsic stability of the FTS of a level of 1 m/s over 90 hours. The
difference between the FP RVs and the iodine cell RVs show no significant
trends during the same time span. The RMS of the RV difference between FP and
iodine cell is 10.7 cm/s, which can be largely attributed to the intrinsic RV
precisions of the iodine cell and the FP (10.2 cm/s and 1.0 cm/s,
respectively). This shows that we can calibrate the FTS to a level of 10 cm/s,
competitive with current state-of-the-art precision RV instruments. Based on
these results we argue that the spectrum of iodine can be used as an absolute
reference to reach an RV accuracy of 10 cm/s.Comment: 13 pages, 9 figures, to be published in Journal of Astronomical
Telescopes, Instruments, and Systems (JATIS
Supplementary_material - A Targeted Literature Review of the Disease Burden in Patients With Symptomatic Peripheral Artery Disease
No full textSupplementary_material for A Targeted Literature Review of the Disease Burden in Patients With Symptomatic Peripheral Artery Disease by Rupert Bauersachs, Sebastian Debus, Mark Nehler, Maria Huelsebeck, Janita Balradj, Kevin Bowrin and Jean-Baptiste Briere in Angiology</p
Replication Data for: Towards 10 cm/s radial velocity accuracy using a Fourier transform spectrometer
No full textFTS-Spectra, extracted radial velocities, temperature data as well as code used in evaluation for the aforementioned paper
Prior surgical intervention and tumor size impact clinical outcome after precision radiotherapy for the treatment of optic nerve sheath meningiomas (ONSM)
No full textAbstract Purpose We analyzed our long-term experience with fractionated stereotactic radiotherapy (FSRT) in patients with meningioma of the optic nerve sheath (ONSM). Patients and Methods Between January 1991 and January 2010, 40 patients with ONSM were treated using FSRT. Of these, 19 patients received radiotherapy as primary treatment, and 21 patients were treated after surgical resection. The median target volume was 9.2 ml, median total dose was 54 Gy in median single fractions of 1,8 Gy. Results Local progression-free survival was 100%. Median survival after FSRT was 60 months (range 4-228 months). In all patients overall toleration of FSRT was very good. Acute toxicity was mild. Prior to RT, 29 patients complained about any kind of visual impairment including visual field deficits, diplopia or amaurosis. Prior surgical resection was identified as a negative prognostic factor for visual outcome, whereas patients with larger tumor volumes demonstrated a higher number of patients with improvement of pre-existing visual deficits. Conclusion Long-term outcome after FSRT for ONSM shows improved vision in patients not treated surgically prior to RT; moreover, the best improvement of visual deficits are observed in patients with larger target volumes. The absence of tumor recurrences supports that FSRT is a strong alternative to surgical resection especially in small tumors without extensive compression of normal tissue structures</p
Online_Appendix – Supplemental material for Chemoradiation in female patients with anal cancer: Patient-reported outcome of acute and chronic side effects
No full textSupplemental material, Online_Appendix for Chemoradiation in female patients with anal cancer: Patient-reported outcome of acute and chronic side effects by Stefan A. Koerber, Ben Seither, Alla Slynko, Matthias F. Haefner, David Krug, Jakob Liermann, Sebastian Adeberg, Klaus Herfarth, Juergen Debus and Florian Sterzing in Tumori Journal</p
Combinatorics of Reflection Groups and Real Algebraic Geometry
No full textReal algebraic geometry studies sets defined by a finite system of real polynomial equalities and inequalities. A central topic in this area is the study of the cone of nonnegative polynomials. Verifying that a given polynomial is nonnegative is an NP-hard problem. However, it turns out to be algorithmically much more feasible to verify if a given polynomial admits a representation into a sum of squares of polynomials, and such a decomposition provides a certificate for nonnegativity. Therefore, understanding the sets of sums of squares and nonnegative polynomials provides applications to various fields such as polynomial optimization and graph theory. In this thesis, tropicalization and the combinatorics of reflection groups are exploited to examine the cones of invariant sums of squares forms and nonnegative forms, and to study invariant systems of equations.
In these contexts the thesis provides new insights in the description of sums of squares invariant under infinite series of essential reflection groups, the asymptotic behavior of the cones of symmetric and even symmetric sums of squares and nonnegative forms, and the ideals corresponding to the irreducible representations of the hyperoctahedral group
Robotic radiosurgery using „Cyberknife M6“ at Heidelberg University Hospital – initial clinical experience in the first 145 patients
No full textGlioblastoma recurrence pattern: Radiologic Evaluation of the Recurrence pattern of 608 Patients in Relation to neural Stem Cells of the subventricular Zone
No full text
Long-term outcome after radiotherapy in patients with atypical and malignant meningioma - Clinical results in 85 patients treated in a single institution
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