Dynamic LL(k) parsing

A new class of context-free grammars, called dynamic context-free grammars, is introduced. These grammars have the ability to change the set of production rules dynamically during the derivation of some terminal string. The notion of LL() parsing is adapted to this grammar model. We show that dynamic LL() parsers are as powerful as LR() parsers, i.e. that they are capable to analyze every deterministic context-free language while using only one symbol of lookahead. Received: 24 August 1994 / 5 January 1996     

Quantification of the thaumatin-like kiwi allergen by a monoclonal antibody-based ELISA

Thaumatin-like proteins (TLPs) have been established as a new family of fruit and pollen allergens. The aim of this study was to develop a two-site ELISA for the quantification of the thaumatin-like kiwi allergen (Act d 2) in kiwifruit extracts and kiwifruit-containing food products. Genomic DNA (gDNA) of Act d 2 was amplified and the deduced amino acid sequence was determined to obtain a primary structure. Act d 2 purified from kiwifruit extract by HPLC was identified by Edman degradation and MS. Balb/c mice were immunized with Act d 2 for the production of mAbs by hybridoma technology. The optimized ELISA measured Act d 2 concentrations ranging from 0.2 to 9.0 ng/mL, with intra- and interassay coefficients of variation of 3.65 and 10.44%, respectively. The developed ELISA is a useful method for the quantification of the thaumatin-like kiwi allergen in kiwifruit extracts as well as the allergen level in kiwifruit-containing food products. It may be a helpful analytical tool for the evaluation of the stability (integrity) of fruit allergen extracts for in vitro diagnosis.     

Standards für die Beratung zu Patientenverfügungen

Ohne ZusammenfassungDie Standards wurden von der Arbeitsgruppe Standards für Beratung zu Patientenverfügungen in der Akademie für Ethik in der Medizin e.V. (AEM) erarbeitet. Mitglieder der Arbeitsgruppe sind: Eggert Beleites, Georg Beule, Jürgen Bickhardt, Linus Geisler, Eugen Engels, Lilo Brombacher-Böß, Sylke Geißendörfer, Brigitte Huber, Carmen Kaminsky, Rita Kielstein, Hartmut Kreß, Klaus Kutzer, Arnd T. May, Hans Georg Nehen, Silke Niewohner, Birgitt van Oorschot, Wolfgang Putz, Susanne Roller, Sonja Rothärmel, Hans-Martin Sass, Alfred Simon, Wilhelm Uhlenbruck, Petra Vetter, Elke Zeller.Arbeitsgruppen in der AEM sind offene Foren für den Austausch unterschiedlicher Standpunkte und Positionen. Der Inhalt der von ihnen veröffentlichten Beiträge wird allein von den genannten Autorinnen und Autoren verantwortet. Er repräsentiert nicht notwendigerweise die Meinung der AEM oder ihrer Organe.     

Prototyping realistic programming languages based on formal specifications

The specification of realistic programming languages is difficult and expensive. One approach to make language specification more attractive is the development of techniques and systems for the generation of language–specific software from specifications. To contribute to this approach, a tool–based framework with the following features is presented: It supports new techniques to specify more language aspects in a static fashion. This improves the efficiency of generated software. It provides powerful interfaces to generated software components. This facilitates the use of these components as parts of language–specific software. It has a rather simple formal semantics. In the framework, static semantics is defined by a very general attribution technique enabling e.g. the specification of flow graphs. The dynamic semantics is defined by evolving algebra rules, a technique that has been successfully applied to realistic programming languages. After providing the formal background of the framework, an object–oriented programming language is specified to illustrate the central specification features. In particular, it is shown how parallelism can be handled. The relationship to attribute grammar extensions is discussed using a non-trivial compiler problem. Finally, the paper describes new techniques for implementing the framework and reports on experiences made so far with the implemented system. Received: 20 November 1995 / 20 January 1997     

Ventilation of passenger car cabins: comparison of experimental data and numerical calculations

The complex flow in the interior of a passenger car cabin is measured and calculated in a Reynolds number range of practical importance. It turns out that the mean flow field compares quite well, even in minor details. But, experiments and calculations deviate considerably as far as turbulent quantities are concerned. The situation is analysed by a closer look to the physics of the flow field. From this, conclusions are drawn why the k−ɛ model applied here might be inappropriate for the flow field under consideration.     

Invited Paper: UHP‐lamp systems for projection applications

Abstract— Projection systems have found widespread use in conference rooms and other professional applications during the last decade and are now entering the home‐TV market with considerable pace. Projectors as small as about one liter are nowadays able to deliver a screen flux of several thousand lumens and are, with a system efficacy of more than 10 lm/W, the most‐efficient display system realized today. Because such highly efficient projectors employ microdisplays as light valves, short‐arc lamps are a key component in realizing these properties. The introduction of the UHP‐lamp system by Philips in 1995 can be identified as one of the key enablers for the commercial success of projection systems. The ultra‐high‐performance (UHP) lamp concept features outstanding arc luminance, a well‐suited spectrum, long life, and excellent flux maintenance. For the first time, it combines a very‐high‐pressure mercury‐discharge lamp having an extremely short and stable arc length with a regenerative chemical cycle that keeps the discharge walls free from blackening, leading to lifetimes of over 10,000 hours. In this review, the most important aspects of the UHP concept that enabled its success in the projection market are described, followed by a discussion of some recent additions to the UHP‐product portfolio.     

Sulfur-impregnated activated carbon fiber cloth as a binder-free cathode for rechargeable Li-S batteries

A route for the preparation of binder-free sulfur-carbon cathodes is developed for lithium sulfur batteries. The method is based on the impregnation of elemental sulfur into the micropores of activated carbon fibers. These electrodes demonstrate good electrochemical performance at high current density attributed to the uniform dispersion of sulfur inside the carbon fiber.     

Loss of HCN2 in Dorsal Hippocampus of Young Adult Mice Induces Specific Apoptosis of the CA1 Pyramidal Neuron Layer

Neurons inevitably rely on a proper repertoire and distribution of membrane-bound ion-conducting channels. Among these proteins, the family of hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels possesses unique properties giving rise to the corresponding I_h-current that contributes to various aspects of neural signaling. In mammals, four genes (hcn1-4) encode subunits of HCN channels. These subunits can assemble as hetero- or homotetrameric ion-conducting channels. In order to elaborate on the specific role of the HCN2 subunit in shaping electrical properties of neurons, we applied an Adeno-associated virus (AAV)-mediated, RNAi-based knock-down strategy of hcn2 gene expression both in vitro and in vivo. Electrophysiological measurements showed that HCN2 subunit knock-down resulted in specific yet anticipated changes in I_h-current properties in primary hippocampal neurons and, in addition, corroborated that the HCN2 subunit participates in postsynaptic signal integration. To further address the role of the HCN2 subunit in vivo, we injected recombinant (r)AAVs into the dorsal hippocampus of young adult male mice. Behavioral and biochemical analyses were conducted to assess the contribution of HCN2-containing channels in shaping hippocampal network properties. Surprisingly, knock-down of hcn2 expression resulted in a severe degeneration of the CA1 pyramidal cell layer, which did not occur in mice injected with control rAAV constructs. This finding might pinpoint to a vital and yet unknown contribution of HCN2 channels in establishing or maintaining the proper function of CA1 pyramidal neurons of the dorsal hippocampus.     

Lattice Metamaterials with Mesoscale Motifs: Exploration of Property Charts by Bayesian Optimization

Through the current work, the usefulness of the concept of architectured rod lattices based on unit cell motifs designed at mesoscale is demonstrated. Specifically, 2D triangular lattices with unit cells containing different numbers of rods are considered. Combinations of rods of two different types provide the lattices explored with a greater complexity and versatility. For mesocells with a large number of variable parameters, it is virtually impossible to calculate the entire set of the points mapping the material onto its property space, as the volume of calculations would be gigantic. The number of possible motifs increases exponentially with the number of rods. Herein, the lattice metamaterials with mesoscale motifs are investigated with the focus on their elastic properties by combining machine learning techniques (specifically, Bayesian optimization) with finite element computations. The proposed approach made it possible to construct property charts illustrating the evolution of the boundary of the elastic compliance tensor of lattice metamaterials with an increase in the number of rods of the mesocell when a full-factor experiment would not be possible.     

Modular specification of frame properties in JML

We present a modular specification technique for frame properties. The technique uses modifies clauses and abstract fields with declared dependencies. Modularity is guaranteed by a programming model that enforces data abstraction by preventing representation and argument exposure, a semantics of modifies clauses that uses a notion of ‘relevant location’, and by modularity rules for dependencies. For concreteness, we adapt this technique to the Java Modeling Language, JML. Copyright © 2003 John Wiley & Sons, Ltd.