bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hyperdatenbanken zur Verwaltung von Informationsräumen (Hyperdatabases for Managing Information Spaces)
Authors: Schek Hans-Jörg , Schuldt Heiko , Schuler Christoph , Türker Can , Weber Roger 
Published: April 2004

Zusammenfassung
Mit den enormen Fortschritten in der Kommunikationstechnologie wächst die ehemals in isolierten Daten- und Dokumentenkollektionen verwaltete Information zu einem dicht verwobenen Verbund von Informationskomponenten – zu einem Informationsraum – zusammen. Um die damit verbundene Informationsflut in den Griff zu bekommen, ist eine neue Infrastruktur gefordert, die Koordinationsprozesse und zusammengesetzte Dienste unterstützt und deren korrekte Ausführung auch bei Systemfehlern und Nebenläufigkeit garantiert. Dieser Artikel skizziert das Konzept einer Hyperdatenbank, die eine verteilte und hochgradig skalierbare Infrastruktur eines beliebig großen, dynamischen Informationsraumes bereitstellt. Die Grundidee besteht darin, den kooperierenden Diensten eine zusätzliche Schicht hinzuzufügen, die wir Hyperdatenbankschicht nennen. Während die Vernetzung Bytes durch den Informationsraum transportiert, ist die Hyperdatenbankschicht – neben anderen Aufgaben – für die korrekte Ausführung von dienstübergreifenden Prozessen zuständig.
Einsatz von Mechanismen aktiver Datenbanken beim Entwurf eingebetteter Systeme (Supporting the Development of Embedded Systems by Mechanisms of Active Databases)
Authors: Monjau Dieter , Sporer Mathias , Strätling Adrian 
Published: April 2004

Zusammenfassung
Für den Entwurf eingebetteter Systeme existieren hoch entwickelte Entwurfs- und Simulationswerkzeuge. Bei einer konkreten Entwicklungsaufgabe muss es dem Entwurfsingenieur möglich sein, in einer Wissensbasis vorhandenes Entwurfswissen nachzunutzen und die Konsistenz aller Entwurfsdaten unabhängig von deren Verwaltung in speziellen Tools zu sichern. Der vorliegende Beitrag beschreibt, wie der Wissensingenieur bei der Wartung von Wissensbasen moderne Entwicklungen aus dem Bereich aktiver Datenbanksysteme nutzen kann, um ohne Kenntnisse der Interna eines konkreten DBMS flexible Wissensbasen zu generieren und zu warten, welche die konsistente Verwaltung seiner Entwurfsdaten sichern.
C#: eine Konkurrenz für Java? (C#: a Competitor of Java?)
Authors: Winkler Jürgen F. H. 
Published: April 2004

Zusammenfassung
C# ist eine neue Programmiersprache, die im Wesentlichen bei Microsoft entwickelt worden ist. Erste Fassungen der Sprachdefinition wurden im Jahre 2000 veröffentlicht, im Dezember 2001 wurde bei ECMA die Norm ECMA-334 und im März 2003 bei ISO die Norm 23270 verabschiedet. C# ist inhaltlich gesehen eine Erweiterung von Java. Die Erweiterungen bestehen aus der Einführung neuer Sprachelemente wie zum Beispiel Delegate, Event und Property, und aus der Verbesserung vorhandener Elemente, wie zum Beispiel der Switch-Anweisung. Das technische Konzept der Implementierung weist ebenfalls Verbesserungen auf, und nicht zuletzt ist die Sprachdefinition noch etwas übersichtlicher als die auch recht gute Definition von Java. Der Aufsatz gibt einerseits einen Überblick über die Geschichte von C# und Java und stellt andererseits die Neuerungen anhand von kleinen Beispielen vor. Abschließend wird auf einige Defizite hingewiesen, die vor allem auf der Verwurzelung in der C-Welt beruhen.
Sonderforschungsbereich 588: Humanoide Roboter – Lernende und kooperierende multimodale Roboter (Humanoid Robots – Learning and Cooperating Multimodal Robots)
Authors: Steinhaus Peter , Becher Regine , Dillmann Rüdiger 
Published: April 2004

Zusammenfassung
Ziel des Sonderforschungsbereiches 588 “Humanoide Roboter” ist es, Konzepte, Methoden und Komponenten für einen humanoiden Roboter zu entwickeln, der seinen Arbeitsbereich mit dem Menschen teilt. Die Schwerpunkte unserer Forschungstätigkeit liegen dabei in folgenden Bereichen: Entwicklung mechatronischer Komponenten und Konstruktion eines Demonstratorsystems, Perzeption von Benutzer und Umgebung, Modellierung und Simulation von Roboter, Umgebung und Benutzer, sowie Mensch-Roboter-Kooperation und Lernen auf unterschiedlichen Verhaltensebenen. Durch das in diesem Sonderforschungsbereich entwickelte “teilanthropomorphe Robotersystem” soll der Schritt zu kooperierenden, multimodalen und lernenden Robotersystemen vollzogen werden.
Local crystallography of crystals with disorder
Authors: Egami Takeshi 
Published: April 2004

Abstract
The assumption of perfect periodicity in the crystal lattice is the most basic tenet of crystallography. However, many materials are not crystalline. Even when they are the atomic structure of real materials is often less than perfectly periodic, and usually deviations from perfect periodicity have significant effects on their properties. Thus in order to characterize the structure of real materials by diffraction the crystallographic approaches need to be complemented by other methods focusing on disorder. B. E. Warren was a pioneer of such alternative, non-crystallographic approaches, including the method of atomic pair-density function (PDF) analysis. With the advent of synchrotron based radiation sources, such as pulsed neutron sources and synchrotron radiation sources, it recently became possible to apply the PDF technique on crystals with and without disorder, covering the whole spectrum of structural order and disorder. Here some of the recent progresses in this approach made in my research group are reviewed.
PDF analysis – from atomic displacements to nanocrystals
Authors: Dmowski Wojtek , Swider-Lyons Karen E. 
Published: April 2004

Abstract
Atomic pair-density function (PDF) analysis is an ideal approach for examining the local- and medium-range atomic structures of materials. PDF has been widely used in the studies of glasses and liquids and has also been applied successfully to characterize the local and complex structures of crystalline solids. Using PDF analysis, we demonstrate that important conclusions can be drawn about how the short-and long-range atomic structure of several oxide and hydrous oxide materials relates to their physical and electrochemical properties. For example, in Pb based ferroelectric relaxors, the diffraction pattern suggests a simple perovskite structure, while the PDF analysis shows that, in reality, the Pb atoms are strongly displaced from the high symmetry positions, so they can contribute to the electrical polarization. In hydrous ruthenium dioxide, RuO2 · x H2O, standard X-ray diffraction patterns suggest an “amorphous” structure. However, the PDF method shows that the medium range structure of RuO2 · x H2O is a highly inhomogeneous nanocomposite of ruthenium oxide nanocrystals, dispersed by boundaries of structural water associated with Ru–O. The nanocomposite structure correlates to the unique electrochemical performance of the hydrous RuO2.
Complexity of the phase transition in La1–

x
Sr
x
CoO3
Authors: Louca Despina 
Published: April 2004

Abstract
The complex nature of modern materials is strongly dependent on their intrinsic microstructure. Their collective behaviour at the nanoscale strongly correlates to their macroscopic functionalities. Thus it has become necessary to understand the true nature of atomic disorder in order to understand its effects on the mechanical, elastic, magnetic and electronic transitions. Carefully calibrated and environment-controlled atomistic measurements can significantly further our understanding of the mechanisms responsible for macroscopic properties. To demonstrate these effects, La1–

x
Sr
x
CoO3 is used as an example as it serves as a prototype for demonstrating lattice distortions through phase transitions.
Structural aspects of the M1 and M2 phases in MoVNbTeO propane ammoxidation catalysts
Authors: DeSanto Peter , Buttrey Douglas J. , Grasselli Robert K. , Lugmair Claus G. , Volpe Anthony F. , Toby Brian H. , Vogt Thomas 
Published: April 2004

Abstract
The structures of M1 and M2 in MoVNbTeO propane ammoxidation catalysts have been solved using a combination of TEM, neutron powder diffraction, and synchrotron X-ray powder diffraction. The unit cell of M1 is Pba2 (No. 32) with a = 21.134(2) Å, b = 26.658(2) Å, c = 4.0146(3) Å and Z = 4. The formula unit is Mo7.8V1.2NbTe0.937O28.9. The unit cell of M2 is Pmm2 (No. 25) with a = 12.6294(6) Å, b = 7.29156(30) Å, c = 4.02010(7) Å and Z = 4. The formula unit is Mo4.31V1.36Te1.81Nb0.33O19.81. Tellurium sites in hexagonal channels of both phases are displaced toward vanadium-occupied framework sites, whereas Te in the heptagonal channel of M1 is near the channel center. The chemical topology resulting from oxidation states and Madelung site potentials presents active moieties for the ammoxidation of propane in M1 and propene in M2. EPR confirmed the presence of V4+ and possibly Mo5+ in M1 and V4+ in M2.
High pressure study of a Zr-based bulk metallic glass and its composite
Authors: Halevy Itzhak , Üstündag Ersan , Salhov S. , Yue Alan F. , Broide A. , Hu Jingzhú 
Published: April 2004

Abstract
Energy dispersive X-ray diffraction was used to study the structural evolution of a bulk metallic glass (BMG) alloy and its composite with W particles under hydrostatic pressure. The diffraction data, especially the pair distribution function (PDF) of the BMG allowed the direct measurement of its elastic strain. The results suggest that PDF patterns of BMGs can be used to deducetheir strain evolution in composites as well as in monolithic form. Although the PDF method of strain measurement in amorphous alloys offers lower resolution compared to the analysis of Bragg reflections from crystalline materials, the PDF techique yields valuable information about the deformation of BMGs.
Nanoporous thin films and porous inorganic substrates for lipid bilayer support materials
Authors: Baker Shenda M. , Kolthammer W. Stephen , Tan Johannes B. , Smith Gregory S. 
Published: April 2004

Abstract
Synthetic lipid bilayers are excellent mimics of cell membranes. In order to experimentally access these thin layers and oriented proteins in membranes, suitable supports which allow for membrane fluidity while assuring membrane stability need to be developed. Nanoporous polymer templates created from the natural phase segregation of immiscible diblock copolymers are uniform arrays with pore sizes naturally on the scale of macromolecules, tens of nanometers, and grain sizes currently on the order of microns. We study the suitability of such templates, appropriately treated to present a hydrophilic surface, as substrates for lipid bilayers with scanning force microscopy and neutron reflectometry. In the process, we use tip deflection curves to establish simple criteria for determining the presence of a lipid layer on the substrates. Gold coated porous polymers and silicon oxide templates in silicon both appear to be suitable support materials.
Using the information seeker to elicit construct models for search engine evaluation
Authors: Crudge Sarah E. , Johnson Frances C. 
Published: April 2004

AbstractWith the rise of interactive search engines, direct access to information is available to the end user. Evaluation of these systems is clearly important for their comparison and development. From the perspective of the user engaged with the system in some information‐seeking task, the range of relevant evaluation factors could be considerable. This article presents an investigation into the suitability of repertory grid technique eliciting a mental model of search engines in the user. Such a model comprises constructs held important to the user, which can be used to evaluate the system. The design of the repertory grid application is described and the data analyzed in two stages. The important issues in determining the suitability of the method are identified and the constructs are analyzed to determine their association, discriminatory ability, and clustering around a central overall rating. From this, it is concluded that repertory grid technique is appropriate for user‐centered determination of evaluative constructs. Further analysis of the characteristics of the resulting construct set is undertaken towards establishing an underlying user model of the search engines, and further research is identified for its use in system evaluation.
Manipulating the covalent link between distal side tryptophan, tyrosine, and methionine in catalase‐peroxidases: An electronic absorption and resonance Raman study
Authors: Santoni Elisa , Jakopitsch Christa , Obinger Christian , Smulevich Giulietta 
Published: April 2004

AbstractElectronic absorption and resonance Raman spectroscopies have been applied to study the ferric and ferrous forms, and fluoride complexes of the Tyr249Phe and Met275Ile variants of the recombinant catalase‐peroxidase (KatG) from the cyanobacterium Synechocystis PCC 6803. Both crystal structures and mass spectrometric analysis demonstrated that Tyr249 and Met275 are part of a novel KatG‐specific covalent adduct including in addition a conserved tryptophan. Its role is not well established, but it has been shown to be essential for the catalase activity. In the present work we investigate the effect of mutation on the protein stability and ligand binding. The results clearly show that mutation weakens the heme binding to the protein, giving rise to a partial conversion from the 5‐coordinate high spin of the wild‐type protein to 6‐coordinate low‐spin heme. An internal ligand binds the heme iron on the distal side as a consequence of protein destabilization and partially prevents the binding of external ligand such as fluoride. The results are compared with those previously reported for the Trp122Ala and Trp122Phe variants. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Spectroscopic study on the enzymatic degradation of a biodegradable composite periodontal membrane
Authors: Reggiani Matteo , Taddei Paola , Tinti Anna , Fagnano Concezio 
Published: April 2004

AbstractThe enzymatic in vitro degradation of a commercial biodegradable hydroxyapatite (HA)‐polymer (poly(ε‐caprolactone)‐poly(oxyethylene)(POE)‐poly(ε‐caprolactone) block copolymer) composite membrane was investigated by Raman and IR spectroscopies in two enzymatic solutions at 37°C: esterase and α‐chymotrypsin in saline phosphate buffer (SPB, pH 7.4). The degradation was found to be faster in the enzymatic medium than in SPB and alkaline solutions. The fastest degradation rate was observed in esterase solution. The trend of properly chosen Raman and IR intensity ratios was evaluated to go deeper inside the degradation mechanism: both polymeric and apatitic components were found to be involved in degradation. The former underwent preferential degradation of POE blocks, while HA is removed by the degradation medium faster than the polymer. Vibrational spectroscopy proved a valid tool for investigating the degradation of the membrane. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Using metabolic flux data to further constrain the metabolic solution space and predict internal flux patterns: the Escherichia coli spectrum
Authors: Wiback Sharon J. , Mahadevan Radhakrishnan , Palsson Bernhard Ø. 
Published: April 2004

AbstractConstraint‐based metabolic modeling has been used to capture the genome‐scale, systems properties of an organism's metabolism. The first generation of these models has been built on annotated gene sequence. To further this field, we now need to develop methods to incorporate additional “omic” data types including transcriptomics, metabolomics, and fluxomics to further facilitate the construction, validation, and predictive capabilities of these models. The work herein combines metabolic flux data with an in silico model of central metabolism of Escherichia coli for model centric integration of the flux data. The extreme pathways for this network, which define the allowable solution space for all possible flux distributions, are analyzed using the α‐spectrum. The α‐spectrum determines which extreme pathways can and cannot contribute to the metabolic flux distribution for a given condition and gives the allowable range of weightings on each extreme pathway that can contribute. Since many extreme pathways cannot be used under certain conditions, the result is a “condition‐specific” solution space that is a subset of the original solution space. The α‐spectrum results are used to create a “condition‐specific” extreme pathway matrix that can be analyzed using singular value decomposition (SVD). The first mode of the SVD analysis characterizes the solution space for a given condition. We show that SVD analysis of the α‐spectrum extreme pathway matrix that incorporates measured uptake and byproduct secretion rates, can predict internal flux trends for different experimental conditions. These predicted internal flux trends are, in general, consistent with the flux trends measured using experimental metabolic flux analysis techniques. © 2004 Wiley Periodicals, Inc.
Quantitative genome‐wide analysis of yeast deletion strain sensitivities to oxidative and chemical stress
Authors: Tucker Chandra L. , Fields Stanley 
Published: April 2004

AbstractUnderstanding the actions of drugs and toxins in a cell is of critical importance to medicine, yet many of the molecular events involved in chemical resistance are relatively uncharacterized. In order to identify the cellular processes and pathways targeted by chemicals, we took advantage of the haploid Saccharomyces cerevisiae deletion strains (Winzeler et al., ). Although ∼4800 of the strains are viable, the loss of a gene in a pathway affected by a drug can lead to a synthetic lethal effect in which the combination of a deletion and a normally sublethal dose of a chemical results in loss of viability. We carried out genome‐wide screens to determine quantitative sensitivities of the deletion set to four chemicals: hydrogen peroxide, menadione, ibuprofen and mefloquine. Hydrogen peroxide and menadione induce oxidative stress in the cell, whereas ibuprofen and mefloquine are toxic to yeast by unknown mechanisms. Here we report the sensitivities of 659 deletion strains that are sensitive to one or more of these four compounds, including 163 multichemical‐sensitive strains, 394 strains specific to hydrogen peroxide and/or menadione, 47 specific to ibuprofen and 55 specific to mefloquine. We correlate these results with data from other large‐scale studies to yield novel insights into cellular function. Copyright © 2004 John Wiley & Sons, Ltd.
Shotgun cloning of transposon insertions in the genome of Caenorhabditis elegans
Authors: van der Linden Alexander M. , Plasterk Ronald H. A. 
Published: April 2004

AbstractWe present a strategy to identify and map large numbers of transposon insertions in the genome of Caenorhabditis elegans. Our approach makes use of the mutator strain mut‐7, which has germline‐transposition activity of the Tc1/mariner family of transposons, a display protocol to detect new transposon insertions, and the availability of the genomic sequence of C. elegans. From a pilot insertional mutagenesis screen, we have obtained 351 new Tc1 transposons inserted in or near 219 predicted C. elegans genes. The strategy presented provides an approach to isolate insertions of natural transposable elements in many C. elegans genes and to create a large‐scale collection of C. elegans mutants. Copyright © 2004 John Wiley & Sons, Ltd.
New computational tools for Brassica genome research
Authors: Love Christopher G. , Batley Jacqueline , Lim Geraldine , Robinson Andrew J. , Savage David , Singh Daniel , Spangenberg German C. , Edwards David 
Published: April 2004

AbstractWith the increasing quantities of Brassica genomic data being entered into the public domain and in preparation for the complete Brassica genome sequencing effort, there is a growing requirement for the structuring and detailed bioinformatic analysis of Brassica genomic information within a user‐friendly database. At the Plant Biotechnology Centre, Melbourne, Australia, we have developed a series of tools and computational pipelines to assist in the processing and structuring of genomic data, to aid its application to agricultural biotechnology research. These tools include a sequence database, ASTRA, a sequence processing pipeline incorporating annotation against GenBank, SwissProt and Arabidopsis Gene Ontology (GO) data and tools for molecular marker discovery and comparative genome analysis. All sequences are mined for simple sequence repeat (SSR) molecular markers using ‘SSR primer’ and mapped onto the complete Arabidopsis thaliana genome by sequence comparison. The database may be queried using a text‐based search of sequence annotation or GO terms, BLAST comparison against resident sequences, or by the position of candidate orthologues within the Arabidopsis genome. Tools have also been developed and applied to the discovery of single nucleotide polymorphism (SNP) molecular markers and the in silico mapping of Brassica BAC end sequences onto the Arabidopsis genome. Planned extensions to this resource include the integration of gene expression data and the development of an EnsEMBL‐based genome viewer. Copyright © 2004 John Wiley & Sons, Ltd.
RNAi for plant functional genomics
Authors: Matthew Louisa 
Published: April 2004

AbstractA major challenge in the post‐genome era of plant biology is to determine the functions of all the genes in the plant genome. A straightforward approach to this problem is to reduce or knock out expression of a gene with the hope of seeing a phenotype that is suggestive of its function. Insertional mutagenesis is a useful tool for this type of study, but it is limited by gene redundancy, lethal knock‐outs, non‐tagged mutants and the inability to target the inserted element to a specific gene. RNA interference (RNAi) of plant genes, using constructs encoding self‐complementary ‘hairpin’ RNA, largely overcomes these problems. RNAi has been used very effectively in Caenorhabditis elegans functional genomics, and resources are currently being developed for the application of RNAi to high‐throughput plant functional genomics. Copyright © 2004 John Wiley & Sons, Ltd.
A comparison of global gene expression measurement technologies in Arabidopsis thaliana
Authors: Coughlan Sean J. , Agrawal Vikas , Meyers Blake 
Published: April 2004

AbstractMicroarrays and tag‐based transcriptional profiling technologies represent diverse but complementary data types. We are currently conducting a comparison of high‐density in situ synthesized microarrays and massively‐parallel signature sequencing (MPSS) data in the model plant, Arabidopsis thaliana. The MPSS data (available at http://mpss.udel.edu/at) and the microarray data have been compiled using the same RNA source material. In this review, we outline the experimental strategy that we are using, and present preliminary data and interpretations from the transcriptional profiles of Arabidopsis leaves and roots. The preliminary data indicate that the log ratio differences of transcripts between leaves and roots measured by microarray data are in better agreement with the MPSS data than the absolute intensities measured for individual microarrays hybridized to only one of the cRNA populations. The correlation was substantially improved by focusing on a subset of genes excluding those with very low expression levels; this selection may have removed noisy data. Future reports will incorporate more than 10 tissues that have been sampled by MPSS. Copyright © 2004 John Wiley & Sons, Ltd.