Application of nested PCR and mass spectrometry for DNA-based virus detection: HBV-DNA detected in the majority of isolated anti-HBc positive sera

DNA preparations from three different groups of serum samples were examined for HBV-DNA via a nested polymerase chain reaction assay (lower detection limit: 10 viral genomes in 100 microliters serum): Group I consisted of 11 uninfected control sera, group II consisted of sera obtained from 11 HBV infected patients and group III consisted of 21 isolated anti-HBc positive samples. The 21 samples from group III were HBV-DNA negative according to a conventional non-nested PCR assay and hybridization with a 32P-labelled probe. Using nested PCR and mass spectrometry, HBV-DNA was detected in none of group I and in all of group II samples. In 11 out of 21 (52%) of the isolated anti-HBc positive sera from group III, HBV-DNA was detected. No correlation was observed between HBV-DNA positivity and anti-HBc titers. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry provided a fast, sensitive and non-radioactive assay for the detection of PCR products without the need for gel electrophoresis or hybridization with labelled probes.     

Microstructural Evolution of Alumina Layers on an Al–Cu–Fe Quasicrystal during High-Temperature Oxidation

The oxidation of a quasicrystal with the nominal compositionAl₆₃Cu₂₅Fe₁₂ was studied around 800°Cin environmental and synthetic air by means of thermogravimetric analysis,electron microscopy, and analytical electron spectroscopy. In an earlyoxidation stage, -Al₂O₃ formed with an orientational relationship tothe quasicrystal. At the oxide–metal interface, -Al₂O₃transformed into large hexagonal shaped -Al₂O₃grains. The change in surface morphology indicated that at theoxide–gas interface -Al₂O₃ continued togrow as -Al₂O₃. Locally the metastable aluminalayer was transformed thoroughly into -Al₂O₃,which then continued to grow with a nodular morphology. On top of the oxidenodules, several at.% of Cu²⁺ were detected.     

A parallel algorithm with enhancements via partial objective value cuts for cluster-based wireless sensor network design

In this paper, we develop a parallel algorithm for the solution of an integrated topology control and routing problem in Wireless Sensor Networks (WSNs). After presenting a mixed-integer linear optimization formulation for the problem, for its solution, we develop an effective parallel algorithm in a Master–Worker model that incorporates three parallelization strategies, namely low-level parallelism, domain decomposition, and multiple search (both cooperative and independent) in a single Master–Worker framework.     

Synthese von substituierten benzotriazolen zur stabilisierung aromatischer polyamide gegen UV-licht

2-(2′-Hydroxyphenyl)-benzotriazoles, containing a carbonamide group in 5- or 5′-position, were synthesized to stabilize polyamides. The influence of the ortho-positioned hydroxy group for the stabilizing effect of these substances was examined by methylating it. The synthesized benzotriazoles were characterized, especially with regard to their UV-absorption-spectra. The photolytic resistance of poly-(m-phenyleneisophthalamide), containing these stabilizers, for example 2-(2′-hydroxy-5′-tert-butylphenyl)-benzotriazol-5-carbonic acid anilide, was examined by measuring the viscosity.     

3D ActionSLAM: wearable person tracking in multi-floor environments

We present 3D ActionSLAM, a stand-alone wearable system that can track people in previously unknown multi-floor environments with sub-room accuracy. ActionSLAM stands for action-based simultaneous localization and mapping: It fuses dead reckoning data from a foot-mounted inertial measurement unit with the recognition of location-related actions to build and update a local landmark map. Simultaneously, this map compensates for position drift errors that accumulate in open-loop tracking by means of a particle filter. To evaluate the system performance, we analyzed 23 tracks with a total walked distance of 6,489 m in buildings with up to three floors. The algorithm robustly (93 % of runs converged) mapped the areas with a mean landmark positioning error of 0.59 m. As ActionSLAM is fully stand-alone and not dependent on external infrastructure, it is well suited for patient tracking in remote health care applications. The algorithm is computationally light-weight and runs in real-time on a Samsung Galaxy S4, enabling immediate location-aware feedback. Finally, we propose visualization techniques to facilitate the interpretation of tracking data acquired with 3D ActionSLAM.     

Towards long term monitoring of electrodermal activity in daily life

Manic depression, also known as bipolar disorder, is a common and severe form of mental disorder. The European research project MONARCA aims at developing and validating mobile technologies for multi-parametric, long term monitoring of physiological and behavioral information relevant to bipolar disorder. One aspect of MONARCA is to investigate the long term monitoring of Electrodermal activity (EDA) to support the diagnosis and treatment of bipolar disorder patients. EDA is known as an indicator of the emotional state and the stress level of a person. To realize a long-term monitoring of the EDA, the integration of the sensor system in the shoe or sock is a promising approach. This paper presents a first step towards such a sensor system. In a feasibility study including 8 subjects, we investigate the correlation between EDA measurements at the fingers, which is the most established sensing site, with measurements of the EDA at the feet. The results indicate that 88% of the evoked skin conductance responses (SCRs) occur at both sensing sites. When using an action movie as psychophysiologically activating stimulus, we have found weaker reactivity in the foot than in the hand EDA. The results also suggest that the influence of moderate physical activity on EDA measurements is low and has a similar effect for both recording sites. This suggests that the foot recording location is suitable for recordings in daily life even in the presence of moderate movement.     

Non-standard bone simulation: interactive numerical analysis by computational steering

Numerous numerical methods have been developed in an effort to accurately predict stresses in bones. The largest group are variants of the h-version of the finite element method (h-FEM), where low order Ansatz functions are used. By contrast, we3 investigate a combination of high order FEM and a fictitious domain approach, the finite cell method (FCM). While the FCM has been verified and validated in previous publications, this article proposes methods on how the FCM can be made computationally efficient to the extent that it can be used for patient specific, interactive bone simulations. This approach is called computational steering and allows to change input parameters like the position of an implant, material or loads and leads to an almost instantaneous change in the output (stress lines, deformations). This direct feedback gives the user an immediate impression of the impact of his actions to an extent which, otherwise, is hard to obtain by the use of classical non interactive computations. Specifically, we investigate an application to pre-surgical planning of a total hip replacement where it is desirable to select an optimal implant for a specific patient. Herein, optimal is meant in the sense that the expected post-operative stress distribution in the bone closely resembles that before the operation.     

The multi-agent programming contest from 2005–2010

The Multi-Agent Programming Contest is an annual international event on programming multi-agent systems: Teams of agents participate in a simulated cooperative scenario. It started in 2005 and is organised in 2010 for the sixth time. The contest is an attempt to stimulate research in the area of multi-agent system development and programming by (i) identifying key problems in the field and (ii) collecting suitable benchmarks that can serve as milestones for testing multi-agent programming languages, platforms and tools. This article provides a short history of the contest since it started and reports in more detail on the cows and cowboys scenario implemented for the 2008, 2009 and 2010 contest editions. We briefly discuss the underlying technological background and conclude with a critical discussion of the experiences and lessons learned.