Glyph-based SPECT visualization for the diagnosis of coronary artery disease

Myocardial perfusion imaging with single photon emission computed tomography (SPECT) is an established method for the detection and evaluation of coronary artery disease (CAD). State-of-the-art SPECT scanners yield a large number of regional parameters of the left-ventricular myocardium (e.g., blood supply at rest and during stress, wall thickness, and wall thickening during heart contraction) that all need to be assessed by the physician. Today, the individual parameters of this multivariate data set are displayed as stacks of 2D slices, bull's eye plots, or, more recently, surfaces in 3D, which depict the left-ventricular wall. In all these visualizations, the data sets are displayed side-by-side rather than in an integrated manner, such that the multivariate data have to be examined sequentially and need to be fused mentally. This is time consuming and error-prone. In this paper we present an interactive 3D glyph visualization, which enables an effective integrated visualization of the multivariate data. Results from semiotic theory are used to optimize the mapping of different variables to glyph properties. This facilitates an improved perception of important information and thus an accelerated diagnosis. The 3D glyphs are linked to the established 2D views, which permit a more detailed inspection, and to relevant meta-information such as known stenoses of coronary vessels supplying the myocardial region. Our method has demonstrated its potential for clinical routine use in real application scenarios assessed by nuclear physicians.     

Nonlinear characterization of the performance of production and logistics networks

Today’s networks of production and logistics are often characterized by large structural and dynamical complexity. As a consequence of their nonlinear and potentially unstable dynamics, efficient planning and control is hardly possible, resulting in economic risks. The solution of the corresponding problems requires an overall understanding of the complex behavior of such systems. This paper uses discrete-event simulation to study networks that consist of a low number of cooperating manufacturers. The dynamics of the logistic parameters in the model are analyzed using methods originated in the theory of nonlinear dynamical systems. The results allow evaluation and potential improvement of the performance of different concepts and strategies that may be applied for the control of the dynamics of manufacturing networks.     

Thermal inactivation of tickborne encephalitis virus in milk

Tickborne encephalitis, a zoonotic virus infection, is transmitted to humans usually by the bite of an infected tick. It may also be acquired by ingesting infected dairy products. In this study, the infectivity of tickborne encephalitis virus, suspended in milk and other media, remained unchanged during a period of five days of storage at 8 °C. After heat treatments in the range of 60 to 80 °C, a decrease of approximately 4 or 4.5 log units in the virus titre was observed. Kinetic parameters for the inactivation were calculated, and the line of equal effects showing a 3‐log inactivation was determined.     

Allgemeine bestandteile der lebensmittel

Ohne Zusammenfassung     

Production and physiological action of the disaccharide lactulose

The disaccharide lactulose is an artificial sugar with a significant impact on human digestion. It can be generated by either alkaline isomerization of lactose via the Lobry de Bruyn – Alberda van Ekenstein rearrangement or by enzyme-catalyzed synthesis. Based on the first reaction, different process schemes for the preparation of lactulose have been developed. Maximum yield of lactulose relative to initial lactose concentration Y_lactu/lacto appears to be restricted to 30%, but the presence of complexing agents and further down streaming processes lift Y_lactu/lacto up to 88%. The enzymatic synthesis of lactulose can be carried out using different pathways with the transgalactosylation reaction being the most promising. The dose-dependent effects of lactulose include the enhancement of probiotic intestinal flora as well as an increased colonic motility. The physiological action of lactulose has been focussed by clinical trials for over five decades, leading to its application as pharmaceutical as well as a prebiotic food ingredient.     

Properties of an αs-casein-rich casein fraction: Influence of dialysis on surface properties,miscibility, and micelle formation

In this study, the surface tension, miscibility, and particle size distribution of a solution containing an α_s-casein (CN)-rich CN fraction (54 wt % α_s-CN, 32 wt % β-CN, and 15 wt % κ-CN) were determined at pH 6.6. The nondialyzed CN fraction was compared with a dialyzed one. In the nondialyzed sample, every charge on the protein was compensated by 0.3 charges coming from counterions, whereas in the dialyzed sample, only 0.2 charges could be assigned to each charge on the protein. This relation was determined by calculating the charges at the proteins, taking the measured mineral content into account. The surface tension was measured as a function of the protein concentration by the du Noüy ring method at room temperature. Results indicated alterations in the surface properties after reduction of counterions. The equilibrium surface tension above the critical micelle concentration increased from 40.1 × 10⁻³ to 45 × 10⁻³ N/m, the critical micelle concentration increased from 0.9 × 10⁻⁴ to 2 × 10⁻³ mol/L, and the minimal area occupied per molecule at the surface increased from 2.4 × 10⁻¹⁸ to 4.6 × 10⁻¹⁸ m². Cloud points were determined by measuring the absorbance of CN solutions as a function of the temperature. The cloud points were found to be concentration dependent and had a minimum at 0.2 wt % at 34°C for nondialyzed CN and at 0.25 wt % at 28°C for dialyzed CN, again demonstrating the influence of counterion reduction. Below the cloud point, a micellar phase was found to exist. The hydrodynamic diameter of the micelles were characterized by dynamic light scattering in both auto- and cross-correlation mode. However, no influence of reduction in counterions could be observed, possibly due to the fact that dynamic light scattering is not a suitable method for this type of system. The presence of self-assembled structures was verified by freeze-fracture electron microscopy. The observed differences between dialyzed and nondialyzed samples were explained by changes in the counterion cloud surrounding the proteins. Consequently, the electrostatic interactions between as well as within the CN are altered by dialysis, which, in turn, affects the behavior at the surface as well as the properties in the solution.     

Versuchsaufbau zur beschleunigten Bildung von Fouling aus Magermilchkonzentrat

Air bubbles on heating surfaces have a siginificant influence on fouling of protein containing products. The formation of fouling has been investigated in a pilot plant under constant conditions. Fouling layers were analyzed with respect to mass, thickness and composition. Adsorption of air bubbles on the heating surface, together with a high wall temperature difference, and a low flow velocity resulted in a considerable shortening of the induction period as well as heavy deposits of fouling. The growth of air bubbles within the fouling layer increased with experimental progression.     

Voreen: A Rapid-Prototyping Environment for Ray-Casting-Based Volume Visualizations

The Voreen volume-rendering engine provides an environment for realizing volume visualizations, which exploit GPU-based ray casting techniques. To alleviate the development process, visual prototyping can be peformed by editing a data flow network graph. While this environment gives full flexibility when designing novel visualizations, the component-based architecture ensures that the realized visualization techniques can be exploited in interactive applications without any performance penalty.