Snare technique for coronary sinus cannulation in cardiac resynchronization therapy

PURPOSE Biventricular pacing is a mainstay of therapy for patients with heart failure. However, lead implantations may fail due to anatomical reasons including the impossibility of coronary sinus cannulation. METHODS AND RESULTS A dual approach from the subclavian vein using a snare through a sheath and from the femoral vein using a steerable electrophysiology catheter was performed. Once the snare hooked the catheter, the latter was advanced into the coronary sinus and finally, the sheath could also be advanced in an "over-the-wire" technique. CONCLUSION The snare technique for coronary sinus cannulation offers a "bail-out" strategy for left ventricular lead implantation

XACML Extension for Graphs: Flexible Authorization Policy Specification and Datastore-independent Enforcement

The increasing use of graph-structured data for business- and privacy-critical applications requires sophisticated, flexible and fine-grained authorization and access control. Currently, role-based access control is supported in graph databases, where access to objects is restricted via roles. This does not take special properties of graphs into account such as vertices and edges along the path between a given subject and resource. In previous iterations of our research, we started to design an authorization policy language and access control model, which considers the specification of graph paths and enforces them in the multi-model database ArangoDB. Since this approach is promising to consider graph characteristics in data protection, we improve the language in this work to provide flexible path definitions and specifying edges as protected resources. Furthermore, we introduce a method for a datastore-independent policy enforcement. Besides discussing the latest work in our XACML4G model, which is an extension to the Extensible Access Control Markup Language (XACML), we demonstrate our prototypical implementation with a real case and give an outlook on performance.Comment: Extended version of an accepted paper at the 20th International Conference on Security and Cryptography (SECRYPT), 202

Finanzielle Berichterstattung von PPP unter IPSAS : Ein Projekt in Zusammenarbeit mit der Förderagentur für Innovation des Bundes KTI

In der wissenschaftlichen und politischen Debatte fällt die ambivalente Haltung gegenüber den PPP auf. Auf der einen Seite wird PPP wegen seiner Effizienz- und Effektivitätsvorteile gepriesen und auf der anderen Seite wird PPP als ein Mittel zur Umgehung der Schuldenbremsen betrachtet. Das Ziel unserer Studie ist mit Hilfe der wirtschaftlichen Betrachtungsweise aus der Rechnungslegungstheorie ("Substance over form") eine Brücke zwischen den beiden Lagern zu schlagen: Indem man klare Regeln für eine transparente Berichterstattung festlegt, kann man eine Instrumentalisierung von PPP für fiskalpolitische Spielereien verhindern und rückt so die Wirtschaftlichkeitsbetrachtung von PPP in den Vordergrund. Um dieses Ziel zu erreichen, steht die Beantwortungen der folgenden beiden Forschungsfragen im Zentrum dieser Arbeit: • Wie sind PPP gemäss einer wirtschaftlichen Betrachtungsweise in der Rechnungslegung nach IPSAS abzubilden und wie kann insbesondere der neue IPSAS zu den Dienstleistungskonzessionen in der Praxis angewendet werden? • Welche Auswirkungen hat die wirtschaftliche Betrachtungsweise auf die finanzielle Berichterstattung und die Schuldenbremse? Um diese Fragen zu beantworten, wird in einem ersten Schritt der Forschungsgegenstand PPP umschrieben. Insbesondere wird auf die zwei in der Praxis und Theorie am meisten diskutierten Gesichtspunkte rund um das Konzept PPP eingegangen: Die verdeckte Verschuldung sowie Effizienz- und Effektivitätsvorteile. Diese beiden Aspekte stehen in einem unmittelbaren Zusammenhang mit den Anforderungen der modernen Rechnungslegung und so wird der Bogen zur Darstellung von PPP in der Rechnungslegung auf Basis einer wirtschaftlichen Betrachtungsweise gespannt. Nach einem Überblick über die verschiedenen internationalen Ansätze wird der neue Lösungsansatz vom IPSAS-Board aufgezeigt. Die International Federation of Accountants, welche Projektpartner beim KTI-Projekt PPP unter IPSAS ist, hat unter Mitarbeit des Instituts für Verwaltungs-Management einen Lösungsvorschlag erarbeitet, der vom IPSAS-Board im September 2009 verabschiedet wird. Dieser neue Ansatz von IPSAS wird auf Praxisbeispiele angewendet und dadurch werden die Prinzipien dieses Ansatzes für die Anwendung in der Praxis aufbereitet. Mit den Praxisbeispielen und der strukturierten Übersicht im Anhang soll ein Leitfaden für die Anwendung dieses neuen Ansatzes in der Praxis gegeben werden. Im letzten Kapitel wird der IPSAS-Ansatz aus einer theoretischen Sicht gewürdigt und es werden die Auswirkungen auf die finanzielle Berichterstattung sowie die Schuldenbremse aufgezeigt

Metabolites and dead-end products from the microbial oxidation of quaternary ammonium alcohols

Methyl-triethanol-ammonium originates from the hydrolysis of the parent esterquat surfactant, which is used as softener in fabric care. The initial steps of the catabolism were investigated in cell-free extracts of the bacterial strain MM 1 able to grow with methyl-triethanol-ammonium as sole source of carbon, energy and nitrogen. The initial degradation of methyl-triethanol-ammonium is an enzymatically catalyzed reaction, located in the particulate fraction of strain MM 1. The oxygen dependent reaction occurred also in presence of phenazine methosulfate as an alternative electron acceptor. As soon as one ethanol group of methyl-triethanol-ammonium was oxidized to the aldehyde, cyclic hemiacetals were formed by intramolecular cyclization. The third ethanol group of methyl-triethanol-ammonium was oxidized to the aldehyde and the carboxylic acid sequentially. The structurally related compounds dimethyl-diethanol-ammonium and choline were oxidized as well, whereas (±)-2,3-dihydroxypropyl-trimethyl-ammonium was not converted at all. The structures of the metabolites were established by 1D and 2D 1H, 13C and 14N NMR spectroscopy and by capillary electrophoresis mass spectrometr

Quadriceps Strength and Knee Function After Anterior Cruciate Ligament Reconstruction with Quadriceps Tendon Bone Autograft: A Preliminary Report

Introduction. The purpose of this study was to evaluate quadriceps strength and knee function after anterior cruciate ligament (ACL) reconstruction using a quadriceps tendon bone (QTB) autograft. Methods. Preliminary data were extracted from an ongoing prospective cohort study in which the operative extremity was compared to non-operative extremity. Patients from 14 to 40 years of age who had an ACL reconstruction with QTB autograft volunteered to have knee assessment including quadriceps isokinetic strength measures and functional knee testing at 6 and 12 months postoperatively. Paired t-tests were conducted to compare postoperative strength and function scores on participants who had minimum 1-year post-surgical follow-up. Results. Patients had a significant recovery of quadriceps strength as determined by isokinetic testing and single leg hop test. For 31 participants, quadriceps strength of the operative leg measured at 60 deg/sec was 63% of the non-operative leg at 6 months, increasing to 79% at 1 year (p < 0.001); when measured at 180 deg/sec, these values were 68% at 6 months, increasing to 82% at 1 year (p < 0.001). For 30 participants, single leg hop functional scores of the operative leg were 80% of the non-operative leg at 6 months, increasing to 91% at 1 year (p < 0.001). Conclusions. After QTB autograft for ACL reconstruction, there were significant gains in quadriceps strength and knee function from 6 months to 1 year postoperative. These findings indicate the QTB is an acceptable ACL reconstruction option

Reproducible Research and GIScience: An Evaluation Using GIScience Conference Papers

Ponencia presentada en: 11th International Conference on Geographic Information Science (GIScience 2021)GIScience conference authors and researchers face the same computational reproducibility challenges as authors and researchers from other disciplines who use computers to analyse data. Here, to assess the reproducibility of GIScience research, we apply a rubric for assessing the reproducibility of 75 conference papers published at the GIScience conference series in the years 2012-2018. Since the rubric and process were previously applied to the publications of the AGILE conference series, this paper itself is an attempt to replicate that analysis, however going beyond the previous work by evaluating and discussing proposed measures to improve reproducibility in the specific context of the GIScience conference series. The results of the GIScience paper assessment are in line with previous findings: although descriptions of workflows and the inclusion of the data and software suffice to explain the presented work, in most published papers they do not allow a third party to reproduce the results and findings with a reasonable effort. We summarise and adapt previous recommendations for improving this situation and propose the GIScience community to start a broad discussion on the reusability, quality, and openness of its research. Further, we critically reflect on the process of assessing paper reproducibility, and provide suggestions for improving future assessments

Connectionist Feedforward Networks for Control of Nonlinear Systems

The control of nonlinear systems is addressed from a new perspective, which makes use of several concepts and techniques developed in the area of Artificial Neural Networks. In particular, this work explores the potential of connectionist representations which consist of only feedforward connections of sigmoids or gaussian units. A unified review demonstrating the capabilities of these structures to approximate continuous nonlinear functions is given. The use of the Fourier transform and the properties of kernel functions are exploited in order to demonstrate some properties of gaussian networks. The adjustment of the different parameters plays a significant role in the relevance of these structures in control. For sigmoid networks a new learning algorithm is proposed, its main feature being the use of the forgetting factor and pseudoinverse. For gaussian networks several algorithms using different techniques, such as: the Fourier Transform, gradient approach, and/or clustering algorithm, are explored and compared. The representation of a dynamic system by means of a static nonlinear function, and consequently, by a connectionist representation, is addressed. Concepts such as controllability, observability, and invertibility, which are needed to develop any control structures, are put forward for the nonlinear case. Four control structures using connectionist models to generate the control signal are proposed, and its potential analysed. For each approach a simple example is presented to illustrate their performance. A summary of their main characteristics is also given. Two industrial applications have been tackled, and solutions developed, illustrating not only the differences between different techniques, but also the potential and limitations of the ideas pursued in this work. Finally, some suggestions are given, which may engender further research in the field of control and artificial neural systems

Completion of the Long Duration Wear Test of the NASA HERMeS Hall Thruster

The NASA Hall Effect Rocket with Magnetic Shielding (HERMeS) 12.5-kW Hall thruster has been the subject of extensive technology maturation by NASA GRC and JPL in preparation for development into a flight propulsion system. As part of this effort, a series of wear tests have been conducted to identify erosion phenomena and the accompanying failure modes as well as to validate service-life models for magnetically-shielded thrusters. This work presents a summary of the results obtained during the Long Duration Wear Test (LDWT), which was the third in this wear test series. The LDWT accumulated approximately 3,570 hours of operation and had the overall goal to identify and correct design or facility issues prior to the flight qualification campaign. Thruster performance, stability, and plume properties were invariant throughout the duration of the LDWT and consistent with measurements acquired during previous HERMeS performance and wear characterizations. Average erosion rates of a carbon-carbon composite pole cover were found to match those measured with graphite to within the empirical uncertainty while the previously observed time-dependence of pole cover erosion rates was linked to changes in pole cover roughness. Azimuthal variations in keeper wear rate were observed including deposition on one of the azimuthal-facing sides of the keeper mask. This strongly suggests the presence of an azimuthal component in the process driving keeper erosion