Ethik-Konsultationsdienst nach dem Konzept von J.C. Fletcher an der University of Virginia, Charlottesville, USA

Zusammenfassung.   Es wird die Arbeitsweise der klinischen Ethik-Konsultation am Klinikum der Philipps-Universit?t Marburg anhand eines konkreten Falles dargestellt. Grundlegend für diese Vorgehensweise ist die Theorie und Praxis eines Ethik-Konsildienstes, wie sie am Medical Center der University of Virginia von J.C. Fletcher, F.G. Miller und J.J. Fins entwickelt wurde.      

Effect of the rotor shape on the mixing characteristics of a continuous flow Taylor-vortex reactor

Macro- and micromixing in a continuous flow Taylor-vortex reactor with novel ribbed rotors were investigated and compared to the features of a classical cylindrical rotor. The characterisation was performed in a wide hydrodynamic range (40<Ta<2500 and 0.03<Re<0.51) through tracer experiments and the analysis of the rotor power consumption. Additionally, the flow patterns were visualised by using a rheoscopic fluid. The results show that the novel rotors equipped with ribs immobilise and stabilise the vortices. As compared to cylindrical rotors, micromixing is clearly enhanced while axial dispersion can be simultaneously reduced. Through the use of ribbed rotors, the operational window can be broadened considerably, in which the reactor runs at very low or moderate extent of macromixing.     

Versuche mit neuen Formen von Durchflußdüsen

Ohne Zusammenfassung Mitteilung aus dem Maschinenversuchsfeld „Reiche Zeche” an der Bergakademie Freiberg Ein Erratum zu diesem Beitrag ist unter zu finden.     

Quantification of wild-type mitochondrial DNA and its 4.8-kb deletion in rat organs

Long-term durability of aortic valve allografts may be enhanced by cellular capacities for regeneration and repair. To evaluate aortic valve graft production of an important structural protein, rat aortic roots were implanted heterotopically into the abdominal aorta of recipient rats. Grafts were either syngeneic or strongly allogeneic, were implanted either fresh or after cryopreservation, and were left in place 2 to 21 days after implantation. A total of 80 aortic valve grafts and the corresponding native aortic valves were examined. The grafts were retrieved and immunocytochemically stained for the presence of procollagen, a precursor to collagen. Regardless of histocompatibility or preservation, grafts exhibited consistent procollagen presence that equaled or exceeded that seen in the corresponding native valves. Positive procollagen staining was predominantly in the aortic wall. The most prominent staining was near the hinge point of the valve leaflets, with no staining in the free portion of the leaflets. Staining with alpha-actin demonstrated vascular smooth muscle in sites remote from the areas positive for procollagen, which suggests that vascular smooth muscle was not responsible for the procollagen production. These findings indicate that cryopreservation is compatible with persistent fibroblast viability and in vivo protein synthesis by both syngeneic and allogeneic aortic valve grafts.     

Regelung des Mischungsverhältnisses der Motoren mit äußerer Gemischbildung

Ohne Zusammenfassung     

VC Management for Heterogeneous QoS Multicast Transmissions

A crucial component of the interaction between ATM's and the Internet's Quality of Service (QoS) architectures is the efficient mapping of RSVP (Resource reSerVation Protocol) as the Internet's signalling protocol onto the according ATM mechanisms. In particular, this article focuses on one of the most contrary characteristics of RSVP and ATM signalling. This is the support for heterogeneous reservations by RSVP over the ATM subnetwork, taking into account that ATM only allows for a homogeneous QoS within a single Virtual Circuit (VC). We present previous approaches to the solution of this problem and argue for more sophisticated and efficient approaches to manage ATM VCs taking into consideration ATM tariffs and resource consumption.     

Comparison of Simulated and Measured Synthetic Aperture Radar Image Spectra with Buoy-Derived Ocean Wave Spectra During the Shuttle Imaging Radar B Mission

During the SIR-B mission over the North Sea, two successful synthetic aperture radar (SAR) data takes with simultaneous buoy measurements of ocean wave spectra have been obtained on October 6 and 8, 1984. On October 6, the SAR imaging of ocean waves was predicted as strongly nonlinear and on October 8 as almost linear. The SIR-B experiment confirmed the theoretical predictions. By applying the SAR imaging model based on velocity bunching theory the SAR image spectra are calculated from the measured ocean wave spectra. These calculated SAR image spectra are compared with the SIR-B derived SAR image spectra and it is shown that both agree quite well. This is considered as a further experimental confirmation for the velocity bunching model that has been proposed for describing SAR imaging of ocean surface waves.