Atomistic Visualization of Mesoscopic Whole‐Cell Simulations Using Ray‐Casted Instancing

Molecular visualization is an important tool for analysing the results of biochemical simulations. With modern GPU ray casting approaches, it is only possible to render several million of atoms interactively unless advanced acceleration methods are employed. Whole‐cell simulations consist of at least several billion atoms even for simplified cell models. However, many instances of only a few different proteins occur in the intracellular environment, which can be exploited to fit the data into the graphics memory. For each protein species, one model is stored and rendered once per instance. The proposed method exploits recent algorithmic advances for particle rendering and the repetitive nature of intracellular proteins to visualize dynamic results from mesoscopic simulations of cellular transport processes. We present two out‐of‐core optimizations for the interactive visualization of data sets composed of billions of atoms as well as details on the data preparation and the employed rendering techniques. Furthermore, we apply advanced shading methods to improve the image quality including methods to enhance depth and shape perception besides non‐photorealistic rendering methods. We also show that the method can be used to render scenes that are composed of triangulated instances, not only implicit surfaces.     

Comparison of two rapid whole-blood tests for Helicobacter pylori infection in Chinese patients

Consecutive Chinese patients undergoing endoscopy for dyspepsia were tested for Helicobacter pylori infection by two rapid whole-blood tests: FlexPack HP (Abbott Laboratories) and Helisal One-Step (Cortecs Diagnostics). Biopsy-based tests (rapid urease test and histology) and the [13C]urea breath test were used as the "gold standard." One hundred sixty-one consecutive patients were studied, and 88 (54.7%) were confirmed to have H. pylori infection. The sensitivities, specificities, and positive and negative predictive values were 81.8%, 83.6% (P = 0.008), 85.7% (P = 0.04), and 79.2% for FlexPack HP and 84.1%, 63.0% (P = 0.008), 73.3% (P = 0.047), and 76.7% for Helisal One-Step, respectively.     

A methodical procedure for designing consumer oriented on-demand IT service propositions

IT providers are increasingly facing the challenge to adapt their previously resource oriented service portfolios in order to offer their customers services which explicitly support business processes. Such customer centric service propositions, however, seem to contradict the demand for standardized and automated operational IT processes more than traditional IT service offers, as they are even more subject to customer individual reengineering efforts due to permanently changing business requirements. In order to reconcile increased efficiency in operational processes and effectiveness in consumer oriented service propositions, we propose (1) to predefine all service propositions in consideration of both consumer oriented commitments and operational processes, and (2) to allow for standardized customization by offering a selection of complementary service propositions that extend commitments regarding customer oriented functionality and performance. Such service propositions are aligned with a company’s entities such as workplaces. Thereby the customer organization is enabled to trace, control and adjust commitments, value and expenses of IT services per entity in its business. We introduce a procedural model for designing and on-demand requesting this kind of service propositions, and we illustrate the model’s application and impact by examples taken from two large projects with an associated IT provider.     

Influence of Mould Materials on the Morphological and Mechanical Properties of Injection‐Moulded Prototypes

The use of prototype moulds made with rapid tooling (RT)‐techniques offers the possibility to manufacture prototypes in the series process. Although the series material is used during injection moulding, the properties of the prototype are not identical with the product because of the varying surface qualities of the RT‐moulds and the different thermal conditions in the process. In this work, different RT‐techniques (resin casting, metal spraying, selective laser sintering, investment casting and keltooling) are investigated according to the morphological as well as the mechanical properties of injection‐moulded prototypes. The specimen are compared with parts that were injection‐moulded in a steel mould to realise a comparison between prototype and product. The thermal diffusivity of the analysed RT‐mould materials differs from one tenth of the value of steel up to seven times higher compared to steel. This leads to a different morphology of the prototype concerning the boundary layers and the spherulite size. A good heat conducting material (e. g. aluminium investment casting mould) causes thick boundary layers and small spherulites. In contrast, a rather insulating mould material (e. g. resin casting mould) results in thin boundary layers and large spherulites. The investigations show that the effect of a good heat conducting material can be achieved by using a lower mould temperature for badly conducting materials in the same way. The yield stress of the prototypes differs up to 20% from the mechanical properties of the product and is influenced by the spherulite size and the mould's surface quality. The prototype, moulded in a keltool mould, shows the best resemblance with the product.     

Vergleichende Untersuchungen über die gas-chromatographischen Trenneigenschaften der Polyester aus Äthylenglykol und aliphatischen Dicarbonsäuren

Comparative Studies on the Gas Chromatographic Resolving Properties of Polyesters from Ethylene Glycol and Aliphatic Dicarboxylic Acids Ethylene glycol polyesters of aliphatic dicarboxylic acids (C₄-C₁₀) were synthesized. In the gas chromatographic analysis, the relative retention values for n-paraffins, α-n-olefins, fatty acid methyl esters, fatty alcohol acetates and dicarboxylic acid methyl esters are independent of the molecular weights and the end group distribution of the said liquid phases. With the help of the closely agreeing t_R-values GLC-Spectra were drawn, which enable a rapid identification of the compounds mentioned above with the aid of a few test substances. Mixed polyesters behave in the same way.     

Inverse determination of effective mechanical properties of adhesive bondlines

A new approach for determining effective mechanical bondline properties using a combined experimental–numerical modal analysis technique is proposed. After characterizing clear spruce wood boards, an adhesive layer is applied to the boards’ surfaces. The shift of the eigenfrequencies resulting from the adhesive layer together with information on the bondline geometry can then be used to inversely determine the mechanical properties of the adhesive layer using finite element models. The calculated values for clear wood as well as for the adhesive layer lie within reasonable ranges, thus demonstrating the method’s potential.     

Multipole analysis of meta-atoms

We determine the rigorously calculated scattered field of meta-atoms and decompose it into spherical harmonics with complex amplitudes. Transforming these spherical harmonics into a Cartesian base reveals all multipole moments in this coordinate system, i.e. all electric and magnetic dipole, quadrupole and any higher order moments can be completely determined. We show that these multipole moments provide a deeper understanding on how light interacts with the considered meta-atoms. After sketching the analytical framework, we investigate exemplarily two well-established meta-atoms and show the applicability of our approach.     

Mesh refinement for shape optimization

The numerical solution of shape optimization problems is considered. The algorithm of successive optimization based on finite element techniques and design sensitivity analysis is applied. Mesh refinement is used to improve the quality of finite element analysis and the computed numerical solution. The norm of the variation of the Lagrange augmented functional with respect to boundary variation (residuals in necessary optimality conditions) is taken as an a posteriori error estimator for optimality conditions and the Zienkiewicz—Zhu error estimator is used to improve the quality of structural analysis. The examples presented show meaningful effects obtained by means of mesh refinement with a new error estimator.     

Making sense of randomness: Implicit encoding as a basis for judgment.

People attempting to generate random sequences usually produce more alternations than expected by chance. They also judge overalternating sequences as maximally random. In this article, the authors review findings, implications, and explanatory mechanisms concerning subjective randomness. The authors next present the general approach of the mathematical theory of complexity, which identifies the length of the shortest program for reproducing a sequence with its degree of randomness. They describe 3 experiments, based on mean group responses, indicating that the perceived randomness of a sequence is better predicted by various measures of its encoding difficulty than by its objective randomness. These results seem to imply that in accordance with the complexity view, judging the extent of a sequence's randomness is based on an attempt to mentally encode it. The experience of randomness may result when this attempt fails. (PsycINFO Database Record (c) 2011 APA, all rights reserved)