Interfraction variation and dosimetric changes during image-guided radiation therapy in prostate cancer patients

In dieser Arbeit sollten Volumen- und Dosisänderungen von Blase und Rektum im Verlauf der Tomotherapie bei Patienten mit Prostatakarzinom detektiert werden. Hierzu wurden Blase und Rektum auf wöchentlichen MVCTs rekonturiert und die tatsächlich applizierte Strahlendosis errechnet. Es zeigten sich sowohl für die Blase als auch für das Rektum große Volumen- und Dosisschwankungen mit teils deutlichen Abweichungen vom ursprünglichen Bestrahlungsplan. Ein Entwicklungstrend im Verlauf der Bestrahlung war nicht nachweisbar.The aim of this study was to identify volume changes and dose variations of rectum and bladder during radiation therapy in prostate cancer patients. Therefore bladder and rectum were re-contoured on MVCTs once a week and the actual delivered radiation dose was calculated. For the rectum as well as the bladder, relevant interfraction variations of the organ volume and of the radiation dose could be observed. However, we could not identify a time trend during radiation therapy neither for the volumes nor for the doses

Optimal Design of a Medium-Voltage Grid Analyzer

Much research has been done for medium-voltage applications, where multilevel inverters are challenging classical low-voltage inverters, connected by transformers. Although the decision is very crucial for system costs and performance, comparisons of both approaches are missing, being now introduced for the application of a medium-voltage grid analyzer

Computational Fluid Dynamic Investigations on a Small-Scale Liquid Sodium Loop

Liquid metal heat transfer systems are a technically attractive option to increase the efficiency of CSP plants. Sodium as heat transfer medium is promising especially due to high heat transfer rates. In this paper, basic considerations are made to match the requirements of a small-scale loop with sodium as heat transfer medium. The setup of the test facility KArlsruhe ReceIver test FAcility (KARIFA) to heat up this loop with a 20 kW IR laser is described. The loop is planned as an integrated design using an additive manufacturing process. Different technologies like selective laser melting (SLM) are established processes to realize an integrated design and to bring together components in one part. Some variations must be implemented to adapt these processes to liquid metal loops. The high heat fluxes also demand a flow simulation to ensure an efficient and safe operation. A Reynolds-averaged Navier-Stokes (RANS) steady state simulation was performed to show the surface and duct temperatures as well as dimensionless values to analyse the characteristics of the sodium flow

About the lithospheric structure of central Tibet based on seismic data from the INDEPTH III profile

Signals from 11 shots and 8 earthquakes, and numerous teleseismic events were recorded along the 400-km seismic line INDEPTH III in central Tibet and interpreted together with previous seismic and tectonic data. The abnormal behavior of various mantle phases reveals a complex Moho-transition zone, especially in the northern part of the line, in the Changtang Block, where the lower crust and the mantle show unusually low velocities, a shingled appearance of Pn and no low-velocity layer in the upper crust. The strong east-west anisotropy in the Changtang Block is related to an easterly escape movement of the whole lithosphere, facilitated by the warm and weak layers in the lower crust and the upper mantle, bounded apparently by two prominent west-east running fault zones

UNSEEN: Bewertung der Unsicherheiten in linear optimierenden Energiesystemmodellen unter Zuhilfenahme Neuronaler Netze

Der Einsatz von Modellen zur Erstellung und Untersuchung von Szenarien ist ein wesentliches Instrument der Energiesystemanalyse. Für die Politikberatung ist die Frage nach der Verlässlichkeit von solchen Szenarien von großer Wichtigkeit, da diese mit großen Unsicherheiten behaftet sein können. Diesem Problem wird in UNSEEN begegnet: durch das Abfahren eines sehr großen Parameterraums sollen weit mehr als 1000 Energieszenarien automatisch generiert, berechnet und ausgewertet werden. Hierzu zählen insbesondere auch Extremszenarien. Eine wesentliche Herausforderung ist dabei die Senkung von Modellrechenzeiten zur Lösung gemischt-ganzzahliger Optimierungsprobleme. Im Vorläuferprojekt BEAM-ME wurde mit der Entwicklung und Anwendung des Open Source Solvers PIPS-IPM++ die Voraussetzung für den Einsatz von Hochleistungscomputern zur performanten Lösung dieser Modelle gelegt. Die grundlegende Idee für die Weiterentwicklung ist es eine Methode des Maschinellen Lernens (Reinforcement Learning) zu verwenden, um schnelle Vorhersagen der Ergebnisse eines Optimierungsproblems zu erhalten und diese als Startlösung für einen deterministischen Lösungsalgorithmus zu nutzen. Mittels Modellkopplungen und statistischer Analysen werden ex-post ausführliche Auswertungen des entstehenden Szenarioraums durchgeführt. Hierzu werden multi-kriterielle Indikatoren (u. a. zu Angemessenheit, Betriebssicherheit und Wirtschaftlichkeit) von möglichen, zukünftigen Stromversorgungssystemen ermittelt. Auf dieser Grundlage sollen abschließend Methoden entwickelt werden, um besonders interessante Punkte innerhalb des Szenarioraums gezielt ansteuern können

Phylogeny of the Eurasian Wren Nannus troglodytes (Aves: Passeriformes: Troglodytidae) reveals deep and complex diversification patterns of Ibero-Maghrebian and Cyrenaican populations

Acknowledgments We are indebted to S. Birks (Burke Museum of Natural History and Culture, Seattle, WA, USA) and to J.-M. Pons (L’Institut de Systématique, Évolution, Biodiversité, Muséum national d’histoire naturelle, Paris, France), who kindly provided access to genetic material from their collections. We also thank G. López and CHAGRA ringing group for providing samples. All genetic analyses were performed at SGN-SNSD-Mol-Lab and we are grateful to A. Rauh, C. Spitzweg, A. Müller, and C. Kehlmaier for practical help in the molecular lab facilities. We would also like to thank M. Vamberger for support in phylogenetic analyses. Finally, we would like to thank four anonymous reviewers for constructive criticism on the manuscript. Erratum: Phylogeny of the Eurasian Wren Nannus troglodytes (Aves: Passeriformes: Troglodytidae) reveals deep and complex diversification patterns of Ibero-Maghrebian and Cyrenaican populations (PLoS ONE) (2020) 15: 3 (e0230151) DOI: 10.1371/journal.pone.0230151) F. Albrecht, J. Hering, E. Fuchs, J.C. Illera, F. Ihlow, T.J. Shannon, 2020. PLoS ONEPeer reviewedPublisher PD

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

HDR Brachytherapy and SBRT as Bridging Therapy to Liver Transplantation in HCC Patients: A Single-Center Experience

Background: In the treatment of patients with HCC awaiting liver transplantation (LT), local ablative treatments (LAT) are available either for downstaging or as bridging treatment. We present our clinical experience with both available radiation-based techniques, brachytherapy (BT), and stereotactic body radiotherapy (SBRT). Methods: All patients diagnosed with HCC and who were treated with BT or SBRT at our institution between 2011 and 2018 were retrospectively reviewed. The current analysis included all patients who subsequently underwent LT. Results: A total of 14 patients (male=9; female=5) were evaluated. Seven underwent BT for bridging before LT, and seven were treated with SBRT. BT was performed with a prescribed dose of 1 × 15 Gy, while SBRT was applied with 37 Gy (65%-iso) in three fractions in six patients, and one patient was treated with 54 Gy (100%-iso) in nine fractions. The treatment was generally well tolerated. One case of grade 3 bleeding was reported after BT, and one case of liver failure occurred following SBRT. All patients underwent LT after a median time interval of 152 days (range 47–311) after BT and 202 days (range 44–775) following SBRT. In eight cases, no viable tumor was found in the explanted liver, while four liver specimens showed vital tumor. The median follow-up after SBRT was 41 months and 17 months following BT. Overall, no hepatic HCC recurrence occurred following LT. Conclusion: Both SBRT and BT are feasible and well tolerated as bridging to LT when applied with caution in patients with impaired liver function. Radiation-based treatments can close the gap for patients not suitable for other locally ablative treatment options

Evaluation of uncertainties in linear energy system optimization models using HPC and neural networks

Within the interdisciplinary BMWK-funded project UNSEEN, experts from High Performance Computing, mathematical optimization and energy systems analysis combine strengths to evaluate uncertainties in modeling and planning future energy systems with the aid of High Performance Computing (HPC) and neural networks. Energy System Models (ESM) are central instruments for realizing the energy transition. These models try to optimize complex energy systems in order to ensure security of supply while minimizing costs for power production and transmission. In order to derive reliable and robust policy advice for decision makers, hundreds or even thousands of ESM problems need to be solved in order to address uncertainties in a given model and dataset.Mixed-integer linear programs (MIPs), a direct extension of Linear programs (LPs), can be used to formulate and compute more concrete and realistic energy systems. Since the availability of fast LP solvers is a major prerequisite for optimizing MIPs, the development of an open-source scalable distributed-memory LP solver, called PIPS-IPM++, was started in a preceding project and can already outperform state-of-the-art solvers. A second prerequisite for efficient MIP solving is the availability of MIP heuristics. For this purpose, we develop a generic MIP framework including reinforcement learning methods. Moreover, we aim to implement an efficient automated HPC workflow for generating, solving, and postprocessing numerous ESM problems with a special structure in order to develop new tools for better predictions about the future of our energy system. This novel approach couples multiple existing and new software packages to achieve the project goals