778 research outputs found

    Dynamische Erzeugung von Diagrammen aus standardisierten Geodatendiensten

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    Geodateninfrastrukturen (GDI) erfahren in den letzten Jahren immer weitere Verbreitung durch die Schaffung neuer Standards zum Austausch von Geodaten. Die vom Open Geospatial Consortium (OGC), einem Zusammenschluss aus Forschungseinrichtungen und privaten Firmen, entwickelten offenen Beschreibungen von Dienste-Schnittstellen verbessern die Interoperabilität in GDI. OGC-konforme Geodienste werden momentan hauptsächlich zur Aufnahme, Verwaltung, Prozessierung und Visualisierung von Geodaten verwendet. Durch das vermehrte Aufkommen von Geodiensten steigt die Verfügbarkeit von Geodaten. Gleichzeitig hält der Trend zur Generierung immer größerer Datenmengen beispielsweise durch wissenschaftliche Simulationen an (Unwin et al., 2006). Dieser führt zu einem wachsenden Bedarf an Funktionalität zur effektiven Exploration und Analyse von Geodaten, da komplexe Zusammenhänge in großen Datenbeständen untersucht und relevante Informationen heraus gefiltert werden müssen. Dazu angewendete Techniken werden im Forschungsfeld Visual Analytics (Visuelle Analyse) umfassend beschrieben. Die visuelle Analyse beschäftigt sich mit der Entwicklung von Werkzeugen und Techniken zur automatisierten Analyse und interaktiven Visualisierung zum Verständnis großer und komplexer Datensätze (Keim et al., 2008). Bei aktuellen Web-basierten Anwendungen zur Exploration und Analyse handelt es sich hauptsächlich um Client-Server-Systeme, die auf fest gekoppelten Datenbanken arbeiten. Mit den wachsenden Fähigkeiten von Geodateninfrastrukturen steigt das Interesse, Funktionalitäten zur Datenanalyse in einer GDI anzubieten. Das Zusammenspiel von bekannten Analysetechniken und etablierten Standards zur Verarbeitung von Geodaten kann dem Nutzer die Möglichkeit geben, in einer Webanwendung interaktiv auf ad hoc eingebundenen Geodaten zu arbeiten. Damit lassen sich mittels aktueller Technologien Einsichten in komplexe Daten gewinnen, ihnen zugrunde liegende Zusammenhänge verstehen und Aussagen zur Entscheidungsunterstützung ableiten. In dieser Arbeit wird die Eignung der OGC WMS GetFeatureInfo-Operation zur Analyse raum-zeitlicher Geodaten in einer GDI untersucht. Der Schwerpunkt liegt auf der dynamischen Generierung von Diagrammen unter Nutzung externer Web Map Service (WMS) als Datenquellen. Nach der Besprechung von Grundlagen zur Datenmodellierung und GDIStandards, wird auf relevante Aspekte der Datenanalyse und Visualisierung von Diagrammen eingegangen. Die Aufstellung einer Task Taxonomie dient der Untersuchung, welche raumzeitlichen Analysen sich durch die GetFeatureInfo-Operation umsetzen lassen. Es erfolgt die Konzeption einer Systemarchitektur zur Umsetzung der Datenanalyse auf verteilten Geodaten. Zur Sicherstellung eines konsistenten und OGC-konformen Datenaustauschs zwischen den Systemkomponenenten, wird ein GML-Schema erarbeitet. Anschließend wird durch eine prototypischen Implementierung die Machbarkeit der Diagramm-basierten Analyse auf Klimasimulationsdaten des ECHAM5-Modells verifiziert.Spatial data infrastructures (SDI) have been subject to a widening dispersion in the last decade, through the development of standards for the exchange of geodata. The open descriptions of service interfaces, developed by the OGC, a consortium from research institutions and private sector companies, alter interoperability in SDI. Until now, OGC-conform geoservices are mainly utilised for the recording, management, processing and visualisation of geodata. Through the ongoing emergence of spatial data services there is a rise in the availability of geodata. At the same time, the trend of the generation of ever increasing amounts of data, e. g. by scientific simulation (Unwin et al., 2006), continues. By this, the need for capabilities to effectively explore and analyse geodata is growing. Complex relations in huge data need to be determined and relevant information extracted. Techniques, which are capable of this, are being described extensively by Visual Analytics. This field of research engages in the development of tools and techniques for automated analysis and interactive visualisation of huge and complex data (Keim et al., 2008). Current web-based applications for the exploration and analysis are usually established as Client-Server approaches, working on a tightly coupled data storage (see subsection 3.3). With the growing capabilities of SDI, there is an increasing interest in offering functionality for data analysis. The combination of widely used analysis techniques and well-established standards for the treatment of geodata may offer the possibility of working interactively on ad hoc integrated data. This will allow insights into large amounts of complex data, understand natural interrelations and derive knowledge for spatial decision support by the use of state-of-the-art technologies. In this paper, the capabilities of the OGC WMS GetFeatureInfo operation for the analysis of spatio-temporal geodata in a SDI are investigated. The main focus is on dynamic generation of diagrams by the use of distributed WMS as a data storage. After the review of basics in data modelling and SDI-standards, relevant aspects of data analysis and visualisation of diagrams are treated. The compilation of a task taxonomy aids in the determination of realisable spatio-temporal analysis tasks by use of the GetFeatureInfo operation. In the following, conceptual design of a multi-layered system architecture to accomplish data analysis on distributed datasets, is carried out. In response to one of the main issues, a GML-schema is developed to ensure consistent and OGC-conform data exchange among the system components. To verify the feasibility of integration of diagram-based analysis in a SDI, a system prototype is developed to explore ECHAM5 climate model data

    Waiting for surgery from the patient perspective

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    The aim of this study was to perform a systematic review of the impact of waiting for elective surgery from the patient perspective, with a focus on maximum tolerance, quality of life, and the nature of the waiting experience. Searches were conducted using Medline, PubMed, CINAHL, EMBASE, and HealthSTAR. Twenty-seven original research articles were identified which included each of these three themes. The current literature suggested that first, patients tend to state longer wait times as unacceptable when they experienced severe symptoms or functional impairment. Second, the relationship between length of wait and health-related quality of life depended on the nature and severity of proposed surgical intervention at the time of booking. Third, the waiting experience was consistently described as stressful and anxiety provoking. While many patients expressed anger and frustration at communication within the system, the experience of waiting was not uniformly negative. Some patients experienced waiting as an opportunity to live full lives despite pain and disability. The relatively unexamined relationship between waiting, illness and patient experience of time represents an area for future research

    Determining the Sign of the Z-Penguin Amplitude

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    We point out that the precision measurements of the pseudo observables R_b^0, A_b, and A_FB^0,b performed at LEP and SLC suggest that in models with minimal-flavor-violation the sign of the Z-penguin amplitude is identical to the one present in the standard model. We determine the allowed range for the non-standard contribution to the Inami-Lim function C and show by analyzing possible scenarios with positive and negative interference of standard model and new physics contributions, that the derived bound holds in each given case. Finally, we derive lower and upper limits for the branching ratios of K^+ -> pi^+ nu nubar, K_L -> pi^0 nu nubar, K_L -> mu^+ mu^-, B -> X_d,s nu nubar, and B_d,s -> mu^+ mu^- within constrained minimal-flavor-violation making use of the wealth of available data collected at the Z-pole.Comment: 20 pages, 5 pdf figures, 5 tables, uses pdflatex; further typos corrected, matches PRD versio

    Comment on ``Relativistic kinetic equations for electromagnetic, scalar and pseudoscalar interactions''

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    It is found that the extra quantum constraints to the spinor components of the equal-time Wigner function given in a recent paper by Zhuang and Heinz should vanish identically. We point out here the origin of the error and give an interpretation of the result. However, the principal idea of obtaining a complete equal-time transport theory by energy averaging the covariant theory remains valid. The classical transport equation for the spin density is also found to be incorrect. We give here the correct form of that equation and discuss briefly its structure.Comment: 5 pages LaTe

    Forschungsverbünde für Suchtforschung: Fragestellungen und Inhalte

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    Mit dieser Arbeit soll näher auf die einzelnen Verbünde eingegangen und die einzelnen Projekte kurz vorgestellt werden. Dies kann in solch einem Artikel natürlich nur in dem Umfang geleistet werden, der den Interessierten einen Überblick über die Forschungstätigkeit gestattet. Detailliertere Informationen können den angegebenen Literaturstellen oder den inzwischen eingerichteten Internet-Angeboten entnommen werden

    FINEX: A Fast Index for Exact & Flexible Density-Based Clustering (Extended Version with Proofs)*

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    Density-based clustering aims to find groups of similar objects (i.e., clusters) in a given dataset. Applications include, e.g., process mining and anomaly detection. It comes with two user parameters ({\epsilon}, MinPts) that determine the clustering result, but are typically unknown in advance. Thus, users need to interactively test various settings until satisfying clusterings are found. However, existing solutions suffer from the following limitations: (a) Ineffective pruning of expensive neighborhood computations. (b) Approximate clustering, where objects are falsely labeled noise. (c) Restricted parameter tuning that is limited to {\epsilon} whereas MinPts is constant, which reduces the explorable clusterings. (d) Inflexibility in terms of applicable data types and distance functions. We propose FINEX, a linear-space index that overcomes these limitations. Our index provides exact clusterings and can be queried with either of the two parameters. FINEX avoids neighborhood computations where possible and reduces the complexities of the remaining computations by leveraging fundamental properties of density-based clusters. Hence, our solution is effcient and flexible regarding data types and distance functions. Moreover, FINEX respects the original and straightforward notion of density-based clustering. In our experiments on 12 large real-world datasets from various domains, FINEX frequently outperforms state-of-the-art techniques for exact clustering by orders of magnitude

    Protein abundance profiling of the Escherichia coli cytosol

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    <p>Abstract</p> <p>Background</p> <p>Knowledge about the abundance of molecular components is an important prerequisite for building quantitative predictive models of cellular behavior. Proteins are central components of these models, since they carry out most of the fundamental processes in the cell. Thus far, protein concentrations have been difficult to measure on a large scale, but proteomic technologies have now advanced to a stage where this information becomes readily accessible.</p> <p>Results</p> <p>Here, we describe an experimental scheme to maximize the coverage of proteins identified by mass spectrometry of a complex biological sample. Using a combination of LC-MS/MS approaches with protein and peptide fractionation steps we identified 1103 proteins from the cytosolic fraction of the <it>Escherichia coli </it>strain MC4100. A measure of abundance is presented for each of the identified proteins, based on the recently developed emPAI approach which takes into account the number of sequenced peptides per protein. The values of abundance are within a broad range and accurately reflect independently measured copy numbers per cell.</p> <p>As expected, the most abundant proteins were those involved in protein synthesis, most notably ribosomal proteins. Proteins involved in energy metabolism as well as those with binding function were also found in high copy number while proteins annotated with the terms metabolism, transcription, transport, and cellular organization were rare. The barrel-sandwich fold was found to be the structural fold with the highest abundance. Highly abundant proteins are predicted to be less prone to aggregation based on their length, pI values, and occurrence patterns of hydrophobic stretches. We also find that abundant proteins tend to be predominantly essential. Additionally we observe a significant correlation between protein and mRNA abundance in <it>E. coli </it>cells.</p> <p>Conclusion</p> <p>Abundance measurements for more than 1000 <it>E. coli </it>proteins presented in this work represent the most complete study of protein abundance in a bacterial cell so far. We show significant associations between the abundance of a protein and its properties and functions in the cell. In this way, we provide both data and novel insights into the role of protein concentration in this model organism.</p

    Relativistic Kinetic Equations for Electromagnetic, Scalar and Pseudoscalar Interactions

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    We derive the kinetic equations for both the covariant and equal-time Wigner functions of Dirac particles with electromagnetic, scalar and pseudoscalar interactions. We emphasize the constraint equations for the spinor components in the equal-time formulation.Comment: 12 pages, no figures, revte

    Protein abundance profiling of the Escherichia coli cytosol

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    <p>Abstract</p> <p>Background</p> <p>Knowledge about the abundance of molecular components is an important prerequisite for building quantitative predictive models of cellular behavior. Proteins are central components of these models, since they carry out most of the fundamental processes in the cell. Thus far, protein concentrations have been difficult to measure on a large scale, but proteomic technologies have now advanced to a stage where this information becomes readily accessible.</p> <p>Results</p> <p>Here, we describe an experimental scheme to maximize the coverage of proteins identified by mass spectrometry of a complex biological sample. Using a combination of LC-MS/MS approaches with protein and peptide fractionation steps we identified 1103 proteins from the cytosolic fraction of the <it>Escherichia coli </it>strain MC4100. A measure of abundance is presented for each of the identified proteins, based on the recently developed emPAI approach which takes into account the number of sequenced peptides per protein. The values of abundance are within a broad range and accurately reflect independently measured copy numbers per cell.</p> <p>As expected, the most abundant proteins were those involved in protein synthesis, most notably ribosomal proteins. Proteins involved in energy metabolism as well as those with binding function were also found in high copy number while proteins annotated with the terms metabolism, transcription, transport, and cellular organization were rare. The barrel-sandwich fold was found to be the structural fold with the highest abundance. Highly abundant proteins are predicted to be less prone to aggregation based on their length, pI values, and occurrence patterns of hydrophobic stretches. We also find that abundant proteins tend to be predominantly essential. Additionally we observe a significant correlation between protein and mRNA abundance in <it>E. coli </it>cells.</p> <p>Conclusion</p> <p>Abundance measurements for more than 1000 <it>E. coli </it>proteins presented in this work represent the most complete study of protein abundance in a bacterial cell so far. We show significant associations between the abundance of a protein and its properties and functions in the cell. In this way, we provide both data and novel insights into the role of protein concentration in this model organism.</p

    Role for ribosome-associated quality control in sampling proteins for MHC class I-mediated antigen presentation

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    Pathogens and tumors are detected by the immune system through the display of intracellular peptides on MHC-I complexes. These peptides are generated by the ubiquitin−proteasome system preferentially from newly synthesized polypeptides. Here we show that the ribosome-associated quality control (RQC) pathway, responsible for proteasomal degradation of polypeptide chains that stall during translation, mediates efficient antigen presentation of model proteins independent of their intrinsic folding properties. Immunopeptidome characterization of RQC-deficient cells shows that RQC contributes to the presentation of a wide variety of proteins, including proteins that may otherwise evade presentation due to efficient folding. By identifying endogenous substrates of the RQC pathway in human cells, our results also enable the analysis of common principles causing ribosome stalling under physiological conditions.publishedVersio
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