Some characteristics of plastic streamer tubes

The operating characteristics of plastic streamer tubes chosen as a detector of the DELPHI-LEP hadron calorimeter are described. The work has been performed using a set-up specially designed to investigate a hadron calorimeter prototype on a beam of the Dubna synchrophasotron. The apparatus operated on-line with an ES-1040 computer.     

Softwarequalit?tsmodelle – Praxisempfehlungen und Forschungsagenda

Softwarequalit?t birgt für einen Technologiestandort wie Deutschland ein gro?es Potenzial. Sie ist aber gleichzeitig auch eine enorme Herausforderung. Qualit?tsmodelle tragen zur Konsolidierung und Konkretisierung der vielschichtigen Qualit?tsfragestellungen bei. Dieses Papier stellt als Ergebnis der Diskussionen von Qualit?tsexperten aus Forschung und Praxis dar, welche Fragestellungen in der Zukunft am dringlichsten im Bereich der Softwarequalit?tsmodelle bearbeitet werden müssen, um den Stand der Forschung und auch die Praxis entscheidend zu verbessern.     

Natural hybridization in freshwater animals. Ecological implications and molecular approaches

The number of cases where the phenomena of hybridization and gene introgression have been found in species interactions is steadily increasing, in both plant and animal taxa. During the last few years, many examples have been detected even in otherwise well-known freshwater animal taxa. We discuss the topic with respect to ecology and evolutionary processes and compare the main potentials and limitations of allozymes, mitochondrial DNA, and RAPD markers to address some important genetic issues of interspecific hybridization in natural populations of selected freshwater model systems.     

Configuration dependent stiffness of the PUMA 560 manipulator: Analytical and experimental results

Joint stiffness of three PUMA 560 manipulators has been measured experimentally. Results of these studies indicate that stiffness data for joints 1, 2 and 3 are similar between PUMA 560 manipulators. Nonlinear relationships between end effector load, end effector displacement and joint configuration are explained. Because mass and inertia data has already been determined, complete dynamic models of the PUMA 560 manipulator which include joint compliance data, are now possible. Using linearized equilibrium equations, static, compliant, configuration dependent joint deflections are determined and compared with experimental results.     

Parallel‐connected monolithic dye‐sensitised solar modules

Light‐soaking and high‐temperature storage testing of monolithic dye‐sensitised solar modules with total area module efficiencies above 5% have been performed. Our experiences from the development of a four‐layer monolithic dye‐sensitised solar test cell for comparative testing of material components for dye‐sensitised solar cells have directed our module development to a novel device design consisting of parallel‐connection of individual monolithic cells. The results from the accelerated testing of the modules (total area of 17.0 cm²) with four parallel‐connected cells (active area of 3.38 cm²/cell) are equivalent to those obtained for the monolithic single test cells when using identical device components. The successful transfer from cell to module stability is an important milestone in our ambition to develop a low‐cost Photovoltaic (PV) technology. Moreover, our results indicate that intensified research and development to define the procedures for relevant accelerated testing of dye‐sensitised solar modules is urgently required. Copyright © 2010 John Wiley & Sons, Ltd.     

Variable effects of the conserved RNA hairpin element upon 3' end processing of histone pre-mRNA in vitro

We have studied the requirements for efficient histone-specific RNA 3' processing in nuclear extract from mammalian tissue culture cells. Processing is strongly impaired by mutations in the pre-mRNA spacer element that reduce the base-pairing potential with U7 RNA. Moreover, by exchanging the hairpin and spacer elements of two differently processed H4 genes, we find that this difference is exclusively due to the spacer element. Finally, processing is inhibited by the addition of competitor RNAs, if these contain a wild-type spacer sequence, but not if their spacer element is mutated. Conversely, the importance of the hairpin for histone RNA 3' processing is highly variable: A hairpin mutant of the H4-12 gene is processed with almost wild-type efficiency in extract from K21 mouse mastocytoma cells but is strongly affected in HeLa cell extract, whereas an identical hairpin mutant of the H4-1 gene is affected in both extracts. The hairpin defect of H4-12-specific RNA in HeLa cells can be overcome by a compensatory mutation that increases the base complementarity to U7 snRNA. Very similar results were also obtained in RNA competition experiments: processing of H4-12-specific RNA can be competed by RNA carrying a wild-type hairpin element in extract from HeLa, but not K21 cells, whereas processing of H4-1-specific RNA can be competed in both extracts. With two additional histone genes we obtained results that were in one case intermediate and in the other similar to those obtained with H4-1. These results suggest that hairpin binding factor(s) can cooperatively support the ability of U7 snRNPs to form an active processing complex, but is(are) not directly involved in the processing mechanism.     

Comparison EUROMET.EM-K8 of DC voltage ratio: results

A regional key comparison of dc voltage ratio has been carried out in Europe. The method to evaluate the comparison reference value, the resulting degrees of equivalence for the voltage ratios 1000 V/10 V and 100 V/10 V and the link to the corresponding worldwide key comparison CCEM-K8 are reported.     

InAlAs/InGaAs HBT X-band double-balanced upconverter

We report on an InAlAs/InGaAs HBT Gilbert cell double-balanced mixer which upconverts a 3 GHz IF signal to an RF frequency of 5-12 GHz. The mixer cell achieves a conversion loss of between 0.8 dB and 2.6 dB from 5 to 12 GHz. The LO-RF and IF-RF isolations are better than 30 dB at an LO drive of +5 dBm across the RF band. A pre-distortion circuit is used to increase the linear input power range of the LO port to above +5 dBm. Discrete amplifiers designed for the IF and RF frequency ports make up the complete upconverter architecture which achieves a conversion gain of 40 dB for an RF output bandwidth of 10 GHz. The upconverter chip set fabricated with InAlAs/InGaAs HBT's demonstrates the widest gain-bandwidth performance of a Gilbert cell based upconverter compared to previous GaAs and InP HBT or Si-bipolar IC's     

Navigation and Exploration of Interconnected Pathways

Visualizing pathways, i. e. models of cellular functional networks, is a challenging task in computer assisted biomedicine. Pathways are represented as large collections of interwoven graphs, with complex structures present in both the individual graphs and their interconnections. This situation requires the development of novel visualization techniques to allow efficient visual exploration. We present the Caleydo framework, which incorporates a number of approaches to handle such pathways. Navigation in the network of pathways is facilitated by a hierarchical approach which dynamically selects a working set of individual pathways for closer inspection. These pathways are interactively rendered together with visual interconnections in a 2.5D view using graphics hardware acceleration. The layout of individual graphs is not computed automatically, but taken from the KEGG and BioCarta databases, which use layouts that life scientists are familiar with. Therefore they encode essential meta‐information. While the KEGG and BioCarta pathways use a pre‐defined layout, interactions such as linking+brushing, neighborhood search or detail on demand are still fully interactive in Caleydo. We have evaluated Caleydo with pathologists working on the determination of unknown gene functions. Informal experiences confirm that Caleydo is useful in both generating and validating such hypotheses. Even though the presented techniques are applied to medical pathways, the proposed way of interaction is not limited to cellular processes and therefore has the potential to open new possibilities in other fields of application.