29 research outputs found
Information Geometry of Quantum Entangled Gaussian Wave-Packets
Describing and understanding the essence of quantum entanglement and its
connection to dynamical chaos is of great scientific interest. In this work,
using information geometric (IG) techniques, we investigate the effects of
micro-correlations on the evolution of maximal probability paths on statistical
manifolds induced by systems whose microscopic degrees of freedom are Gaussian
distributed. We use the statistical manifolds associated with correlated and
non-correlated Gaussians to model the scattering induced quantum entanglement
of two spinless, structureless, non-relativistic particles, the latter
represented by minimum uncertainty Gaussian wave-packets. Knowing that the
degree of entanglement is quantified by the purity P of the system, we express
the purity for s-wave scattering in terms of the micro-correlation coefficient
r - a quantity that parameterizes the correlated microscopic degrees of freedom
of the system; thus establishing a connection between entanglement and
micro-correlations. Moreover, the correlation coefficient r is readily
expressed in terms of physical quantities involved in the scattering, the
precise form of which is obtained via our IG approach. It is found that the
entanglement duration can be controlled by the initial momentum p_{o}, momentum
spread {\sigma}_{o} and r. Furthermore, we obtain exact expressions for the IG
analogue of standard indicators of chaos such as the sectional curvatures,
Jacobi field intensities and the Lyapunov exponents. We then present an
analytical estimate of the information geometric entropy (IGE); a suitable
measure that quantifies the complexity of geodesic paths on curved manifolds.
Finally, we present concluding remarks addressing the usefulness of an IG
characterization of both entanglement and complexity in quantum physics.Comment: 37 pages, 3 figure
The insect unguitractor plate in action: Force transmission and the micro CT visualizations of inner structures
The application of multi-body simulation approach in the kinematic analysis of beetle leg joints
Development and first assessment of a RGBW-LED diaphanoscope
Background: Diaphanoscopy is an old but still useful technique in ophthalmic diagnostics. Its application suffers somewhat from the fact that the light is strongly attenuated and red-shifted in color when the eye wall is transilluminated.
Material and methods: A color adjustable diaphanoscope prototype is developed based on a powerful red-green-blue-white light-emitting diode (RGBW-LED). Its optical and thermal properties are measured and tested on the porcine eyes of a local butcher. In addition, based on the technical data, the assumed retinal hazard to human eyes is assessed according to the standard DIN EN ISO 15004-2: 2007-6.
Results: The investigated porcine eyes were brightly illuminated with all LED colors. The calculated values for judging the thermal and photochemical hazard were below the limits given in DIN EN ISO 15004-2: 2007-6.
Conclusion: Based on the standard mentioned above, there is no recognizable danger to the human retina when applied for a limited time, and at least in the porcine model, the presented RGBW-LED diaphanoscope allows an adjustable ophthalmological transillumination without the requirement of the more elaborated devices that are usually employed in operating rooms
Efficacy of enoxaparin, certoparin and dalteparin in preventing cardiac catheter thrombosis: an in vitro approach
The direct thrombin inhibitor argatroban effectively prevents cardiac catheter thrombosis in vitro
SummaryThe direct thrombin inhibitor argatroban offers some significant advantages over unfractionated heparin (UFH) and is recommended as an alternative anticoagulant during percutaneous coronary interventions (PCI). The impact of argatroban on cardiac catheter thrombosis – a severe potential complication of PCI – has not been systematically studied yet. The aim of the present study was to test in vitro the hypothesis that argatroban is equivalent to the more established anticoagulants UFH and enoxaparin in preventing catheter thrombus formation. Blood pretreated with the anticoagulants of interest was continuously circulated through a guiding catheter by using a roller pump for a maximum experimental period of 60 minutes. In an alternate model, coagulation was mechanically induced by a magnetic stirrer. Coagulation parameters, overall thrombus weight and electron microscopic features (deposits of platelets and fibrin on the catheter surface) were quantified as endpoints. Argatroban (administered as bolus or continuous in-fusion), UFH (bolus), and enoxaparin (bolus) significantly reduced catheter thrombus formation compared to untreated controls. Here, neither overall thrombus weight nor platelet/fibrin deposition was different among the specific anticoagulants. Declining ACT (activated clotting time) levels – which were found in the argatroban bolus group – could be prevented by continuous infusion. In magnetic stirrer-induced coagulation, thrombus weight was lower following bolus treatment with UFH and enoxaparin compared to argatroban. These data suggest that the potential for argatroban in preventing catheter thrombosis is comparable to that of UFH and enoxaparin. However, the anticoagula-tory efficacy varied, depending on the model of coagulation activation, which demonstrates the necessity for specific testing.</jats:p
