765 research outputs found

    CelticGraph: Drawing Graphs as Celtic Knots and Links

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    Celtic knots are an ancient art form often attributed to Celtic cultures, used to decorate monuments and manuscripts, and to symbolise eternity and interconnectedness. This paper describes the framework CelticGraph to draw graphs as Celtic knots and links. The drawing process raises interesting combinatorial concepts in the theory of circuits in planar graphs. Further, CelticGraph uses a novel algorithm to represent edges as B\'ezier curves, aiming to show each link as a smooth curve with limited curvature.Comment: Appears in the Proceedings of the 31st International Symposium on Graph Drawing and Network Visualization (GD 2023

    Entwicklung und Krise des Liberalismus in Österreich

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    Die vorliegende Diplomarbeit befasst sich mit der Krise des Liberalismus, insbesondere der liberalen Parteien in Österreich. Anhand der geschichtlichen sowie politischen Entwicklung des Liberalismus und mit Hilfe von Interviews wird untersucht, warum eine liberale Partei in Österreich, – im Gegensatz zu den liberalen Parteien im Ausland, - so große Probleme hat Fuß zu fassen. Zur Beurteilung der Krise des Liberalismus in Österreich werden grundsätzlich die verschiedenen Definitionen des Liberalismus und seine Formen dargestellt. In der historischen Entwicklung, hauptsächlich von 1848 bis heute, werden die Folgen für den Liberalismus herausgearbeitet, womit die Krisen deutlich werden. Bereits vor über hundert Jahren wurde der Liberalismus von seinen Kritikern in Österreich zu Grabe getragen. In weiterer Folge wird auf die Zeit nach dem Zweiten Weltkrieg und die Versuche der Bildung einer eigenen liberalen Partei („Liberales Forum“) eingegangen. Auch wird hingewiesen, wie radikale nationale Gruppierungen zur Zerschlagung des Liberalismus in Österreich beitrugen. Unter den politischen Sichtweisen wird versucht eine Gegenüberstellung zum Marxismus, Sozialismus, christliche Soziallehre, Neoliberalismus sowie soziale Marktwirtschaft herauszuarbeiten. Bei der Stellung der einzelnen im Nationalrat vertretenen politischen Parteien zum Liberalismus sieht man die Verflechtung liberalen Gedankengutes bei den einzelnen Parteien. Ein wichtiger Punkt, nämlich der Liberalismus und die Europäische Union, zeigt auf, dass auf europäischer Ebene ein mit allen Mitgliedsländern koordinierter Katalog liberaler Werte existiert, der für Österreich Vorbildcharakter haben sollte und man deshalb nicht mehr nur auf das Staatsgrundgesetz über die allgemeinen Rechte der Staatsbürger aus 1867 zurückgreifen muss. Beim Ausblick wird festgestellt, dass zwar das Umfeld für eine eigene liberale Partei nicht gerade positiv ist, eine eigene Partei oder eine Verstärkung der liberalen Werte in den großen Parteien, welche danach ihre Politik ausrichten, aber wünschenswert wäre, weil es nicht nur die Demokratie belebt, sondern weil Liberale eine wichtige Funktion in der Gesellschaft haben. Sie achten darauf, dass die Freiheit des Einzelnen gewahrt bleibt. Sie sind Mahner und ein Korrektiv gegen jeglichen Extremismus, von welcher Seite auch immer

    Influence of Different Beam Energies on the Micro-Bunching Instability

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    During the operation of an electron synchrotron with short electron bunches, the beam dynamics are influenced by the occurrence of the micro-bunching instability. This collective instability is caused by the self-interaction of a short electron bunch with its own emitted coherent synchrotron radiation (CSR). Above a certain threshold bunch current dynamic micro-structures start to occur on the longitudinal phase space density. The resulting dynamics depend on various parameters and were previously investigated in relation to, amongst others, the momentum compaction factor and the acceleration voltage. In this contribution, the influence of the energy of the electrons on the dynamics of the micro-bunching instability is studied based on measurements at the KIT storage ring KARA (Karlsruhe Research Accelerator)

    On the Perturbation of Synchrotron Motion in the Micro-Bunching Instability

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    The self-interaction of short electron bunches with their own radiation field can have a significant impact on the longitudinal beam dynamics in a storage ring. While higher bunch currents increase the power of the emitted CSR which can be provided to dedicated experiments, it simultaneously amplifies the strength of the self-interaction. Eventually, this leads to the formation of dynamically changing micro-structures within the bunch and thus fluctuating CSR emission, a phenomenon that is generally known as micro-bunching or micro-wave instability. The underlying longitudinal dynamics can be simulated by solving the VFP equation, where the CSR self-interaction can be added as a perturbation to the Hamiltonian. In this contribution, we focus on the perturbation of the synchrotron motion that is caused by introducing this additional wake field. Therefore, we adopt the perspective of a single particle and eventually comment on its implications for collective motion. We explicitly show how the shape of the parallel plates CSR wake potential breaks homogeneity in the longitudinal phase space and propose a quadrupole-like mode as potential seeding mechanism of the micro-bunching instability. Moreover, we consider synchrotron motion above the instability threshold and thereby motivate an approach to control of the occurring micro-bunching dynamics. Using dynamically adjusted RF amplitude modulations we can directly address the continuous CSR-induced perturbation at the timescale of its occurrence, which allows for substantial control over the longitudinal charge distribution. While the approach is not limited to this particular application, we demonstrate how this can significantly mitigate the micro-bunching dynamics directly above the instability threshold. The gained insights are supported and verified using the VFP solver Inovesa and put into context with measurements at KARA

    European Association of Cardiothoracic Anesthesiology and Intensive Care (EACTAIC) Fellowship Curriculum: Second Edition

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    This document represents the first update of the Cardiothoracic and Vascular Anaesthesia Fellowship Curriculum of the European Association of Cardiothoracic Anaesthesiology and Intensive Care. After obtaining feedback from exit interviews with fellows in training, graduate fellows, and program directors, 2 modified online Delphi procedures with questionnaires were conducted. A consensus was reached when two-thirds of responding committee members gave green or yellow ratings on a traffic light system, and >70% indicated strong agreement or agreement on a 5-point Likert scale. The new regulations include the following: (1) more flexibility in the fellows` rotation, as long as the total number of days, rotations, and cases are completed during the training year; (2) recommendation for strict compliance with national working-time guidelines; (3) no extension of fellowship training to compensate for annual and/or sick leave, unless the required minimum number of cases and rotations are not reached; (4) interruption of fellowship training for >12 months is allowed for personal or medical reasons; (5) introduction of a checklist for quantitative assessment of standard clinical skills; (6) recommendations for a uniform structure of exit interviews; (7) possibility of a 1-month training rotation in a postanesthesia care unit instead of an intensive care unit; and (8) provided all other requirements have been met, the allowance of progression from the basic training year to the advanced fellowship training year without first passing the transesophageal echocardiography examination

    Benzo-fused Lactams from a Diversity-oriented Synthesis (DOS) Library as Inhibitors of Scavenger Receptor BI (SR-BI)-mediated Lipid Uptake

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    We report a new series of 8-membered benzo-fused lactams that inhibit cellular lipid uptake from HDL particles mediated by Scavenger Receptor, Class B, Type I (SR-BI). The series was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR), measuring the transfer of the fluorescent lipid DiI from HDL particles to CHO cells overexpressing SR-BI. The series is part of a previously reported diversity-oriented synthesis (DOS) library prepared via a build-couple-pair approach. Detailed structure–activity relationship (SAR) studies were performed with a selection of the original library, as well as additional analogs prepared via solution phase synthesis. These studies demonstrate that the orientation of the substituents on the aliphatic ring have a critical effect on activity. Additionally, a lipophilic group is required at the western end of the molecule, and a northern hydroxyl group and a southern sulfonamide substituent also proved to be optimal. Compound 2p was found to possess a superior combination of potency (av IC50 = 0.10 μM) and solubility (79 μM in PBS), and it was designated as probe ML312

    Results from a real-time dosimetry study during left atrial ablations performed with ultra-low dose radiation settings

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    Background: Three-dimensional mapping systems and the use of ultra-low dose radiation protocols have supported minimization of radiation dose during left atrial ablation procedures. By using optimal shielding, scattered radiation reaching the operator can be further reduced. This prospective study was designed to determine the remaining operator radiation exposure during left atrial catheter ablations using real-time dosimetry. Methods: Radiation dose was recorded using real-time digital dosimetry badges outside the lead apron during 201 consecutive left atrial fibrillation ablation procedures. All procedures were performed using the same X‑ray system (Siemens Healthineers Artis dBc; Siemens Healthcare AG, Erlangen, Germany) programmed with ultra-low dose radiation settings including a low frame rate (two frames per second), maximum copper filtration, and an optimized detector dose. To reduce scattered radiation to the operators, table-suspended lead curtains, ceiling-suspended leaded plastic shields, and radiation-absorbing shields on the patient were positioned in an overlapping configuration. Results: The 201 procedures included 139 (69%) pulmonary vein isolations (PVI) (20 cryoballoon ablations, 119 radiofrequency ablations, with 35 cases receiving additional ablation of the cavotricuspid isthmus) and 62 (31%) PVI plus further left atrial substrate ablation. Mean radiation dose measured as dose area product for all procedures was 128.09 ± 187.87 cGy ∙ cm2 with a mean fluoroscopy duration of 9.4 ± 8.7 min. Real-time dosimetry showed very low average operator doses of 0.52 ± 0.10 µSv. A subanalysis of 51 (25%) procedures showed that the radiation burden for the operator was highest during pulmonary vein angiography. Conclusion: The use of ultra-low dose radiation protocols in combination with optimized shielding results in extremely low scattered radiation reaching the operator.Hintergrund: Der Einsatz von dreidimensionalen Mapping-Systemen und von Niedrigdosiseinstellungen der Röntgenanlage führte zu einer Minimierung der Strahlenbelastung bei linksatrialen Ablationen. Optimierte Abschirmung kann die Streustrahlung als Strahlenbelastung des Untersuchers weiter reduzieren. In dieser prospektiven Studie wurde untersucht, welcher Strahlenbelastung der Untersucher unter Anwendung dieser Maßnahmen während linksatrialer Ablationen noch ausgesetzt ist. Methoden: Die Strahlenbelastung wurde mittels Echtzeitdosimetrie an der Außenseite der Bleischürze während 201 konsekutiven linksatrialen Ablationen gemessen. Alle Prozeduren wurden mit demselben Röntgensystem (Siemens Healthineers Artis dBc; Siemens Healthcare AG, Erlangen, Deutschland) und mit strahlensparenden Einstellungen durchgeführt, unter anderem mit einer niedrigen Bildrate von 2 Bildern/s, maximaler Kupferfilterung und angepasster Detektoreingangsdosis. Um Streustrahlung zu reduzieren, wurden die Seitenlamellen, die mobile Acrylscheibe und die strahlenabsorbierenden Schilde auf dem Patienten überlappend angeordnet. Ergebnisse: Die 201 Prozeduren umfassten 139 (69%) Pulmonalvenenisolationen (PVI; 20 Kryoballonablationen, 119 Radiofrequenzablationen, in 35 Fällen mit zusätzlicher Ablation des kavotrikuspidalen Isthmus) und 62 (31%) PVI mit zusätzlicher linksatrialer Substratmodifikation. Die Strahlendosis als Dosis-Flächen-Produkt (DAP) betrug durchschnittlich 128,09± 187,87 cGy ⋅cm2 bei einer Fluoroskopiedauer von imMittel 9,4± 8,7min. Die per Echtzeitdosimetrie erhobene mittlere Strahlendosis des Untersuchers zeigte sich mit 0,52± 0,10 μSv als sehr gering. Eine Subanalyse bei 51 (25 %) Prozeduren zeigte, dass die Strahlendosis des Untersuchers während der Pulmonalvenenangiographie am höchsten war. Schlussfolgerung: Die Kombination von Niedrigdosiseinstellungen und optimierter Abschirmung führt zu einer extremniedrigen Streustrahlung als Strahlenbelastung des Untersuchers
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