857 research outputs found

    A computer program to evaluate the effectiveness of PCM frame synchronization strategies

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    Computer program simulating pulse code modulation /PCM/ conversion equipment using Monte Carlo technique in measuring strategy effectiveness of satellite equipment control setting

    Fusing Data with Correlations

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    Many applications rely on Web data and extraction systems to accomplish knowledge-driven tasks. Web information is not curated, so many sources provide inaccurate, or conflicting information. Moreover, extraction systems introduce additional noise to the data. We wish to automatically distinguish correct data and erroneous data for creating a cleaner set of integrated data. Previous work has shown that a na\"ive voting strategy that trusts data provided by the majority or at least a certain number of sources may not work well in the presence of copying between the sources. However, correlation between sources can be much broader than copying: sources may provide data from complementary domains (\emph{negative correlation}), extractors may focus on different types of information (\emph{negative correlation}), and extractors may apply common rules in extraction (\emph{positive correlation, without copying}). In this paper we present novel techniques modeling correlations between sources and applying it in truth finding.Comment: Sigmod'201

    Conformations Of A Model Protein Revealed By An Aggregating Cuį“µį“µ Porphyrin: Sensing The Difference

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    Aggregated t-CuP binds to poly-L-glutamate through supramolecular interactions, revealing itself to be an extremely sensitive probe for the major conformations of the polymeric scaffold

    Effect Of Zinc Cations On The Kinetics Of Supramolecular Assembly And The Chirality Of Porphyrin J-Aggregates

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    Dilute aqueous solutions of anionic meso-4-sulfonatophenyl-porphyrin (TPPS) extract zinc(ii) ions from glass or quartz surfaces at room temperature and efficiently form the corresponding metal complex (ZnTPPS). The partial or complete formation of ZnTPPS has been probed by UV/Vis spectroscopy and both static and time-resolved fluorescence. The source of zinc(ii) ions has been clearly identified through inductively coupled plasma optical emission spectrometry. The presence of increasing amounts of ZnTPPS slows down the rate of TPPS J-aggregate formation in acid solution. This influences the nucleation step and has a profound impact on the onset of chirality in these species. This evidence indicates the important role of this adventitious metal ion in the interpretation of various spectroscopic and kinetic data for the self-assembly of the TPPS porphyrin and provides some insights into controversial findings on their chirality. The use of this metal derivative as the starting compound for in situ formation of monomeric TPPS is suggested

    Clinical validation of an automated fluorogenic factor XIII activity assay based on isopeptidase activity

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    Hereditary factor XIII (FXIII) deficiency is a rare autosomal bleeding disorder which can cause life-threatening bleeding. Acquired deficiency can be immune-mediated or due to increased consumption or reduced synthesis. The most commonly used screening test is insensitive, and widely used quantitative assays have analytical limitations. The present study sought to validate Technofluor FXIII Activity, the first isopeptidase-based assay available on a routine coagulation analyser, the Ceveron s100. Linearity was evidenced throughout the measuring range, with correlation coefficients of >0.99, and coefficients of variation for repeatability and reproducibility were 5% and 10%, respectively. A normally distributed reference range of 47.0āˆ’135.5 IU/dL was derived from 154 normal donors. Clinical samples with Technofluor FXIII Activity results between 0 and 167.0 IU/dL were assayed with BerichromĀ® FXIII Activity, a functional ammonia release assay, and the HemosILā„¢ FXIII antigen assay, generating correlations of 0.950 and 0.980, respectively. Experiments with a transglutaminase inhibitor showed that Technofluor FXIII Activity can detect inhibition of enzymatic activity. No interference was exhibited by high levels of haemolysis and lipaemia, and interference by bilirubin was evident at 18 mg/dL, a level commensurate with severe liver disease. Technofluor FXIII Activity is a rapid, accurate and precise assay suitable for routine diagnostic use with fewer interferents than ammonia release FXIII activity assays

    Mechanism For Copper(II)-Mediated Disaggregation Of A Porphyrin J-Aggregate

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    J-aggregates of anionic meso-tetrakis(4-sulfonatophenyl)porphyrin form at intermediate pH (2.3ā€“3.1) in the presence of NiSOā‚„ or ZnSOā‚„ (ionic strength, I.S. = 3.2 M). These aggregates convert to monomeric porphyrin units via metallation with copper(II) ions. The kinetics for the disassembly process, as monitored by UV/vis spectroscopy, exhibits zeroth-order behavior. The observed zeroth-order rate constants show a two-term dependence on copper(II) ion concentrations: linear and second order. Also observed is an inverse dependence on hydrogen ion concentration. Activation parameters have been determined for the disassembly process leading to Ī”H^ā‰  = (+163 Ā± 15) kJĀ·molā»Ā¹ and Ī”S^ā‰  = (+136 Ā± 11) JĀ·Kā»Ā¹. A mechanism is proposed in which copper(II) cation is in pre-equilibrium with a reactive site at the rim of the J-aggregate. An intermediate copper species is thus formed that eventually leads to the final metallated porphyrin either through an assisted attack of a second metal ion or through a direct insertion of the metal cation into the macrocycle core
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