305,278 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Block Heavy Hitters

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    e study a natural generalization of the heavy hitters problem in thestreaming context. We term this generalization *block heavy hitters* and define it as follows. We are to stream over a matrixAA, and report all *rows* that are heavy, where a row is heavy ifits ell_1-norm is at least phi fraction of the ell_1 norm ofthe entire matrix AA. In comparison, in the standard heavy hittersproblem, we are required to report the matrix *entries* that areheavy. As is common in streaming, we solve the problem approximately:we return all rows with weight at least phi, but also possibly someother rows that have weight no less than (1-eps)phi. To solve theblock heavy hitters problem, we show how to construct a linear sketchof A from which we can recover the heavy rows of A.The block heavy hitters problem has already found applications forother streaming problems. In particular, it is a crucial buildingblock in a streaming algorithm that constructs asmall-size sketch for the Ulam metric, a metric on non-repetitivestrings under the edit (Levenshtein) distance

    Analysis of Nucleosides and Nucleotides in Milk and Infant Formula

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    Nucleotides have been routinely supplemented to infant formulas due to the important roles they play in metabolism and to replicate the higher concentrations typically found in human milk. A method utilising anion exchange solid-phase extraction clean-up and liquid chromatography was developed for the rapid, routine determination of supplemented cytidine 5′ monophosphate, uridine 5′ monophosphate, inosine 5′ monophosphate, guanosine 5′ monophosphate, and adenosine 5′ monophosphate in bovine milk-based infant formula. Chromatographic analyses were performed using a C18 stationary phase with gradient elution, UV detection, and quantitation by an internal standard technique. A single-laboratory validation was performed, with recoveries of 92–101% and repeatability of 1.0–2.3%. An extension study demonstrated the expansion in scope to a wider range of different infant formula products including milk protein and hydrolysate-based products, low and high fat products, soy protein-based and elemental products, adult nutritional and infant formulations, in both ready-to-feed and powder forms. The development of a method to measure the total potentially available nucleosides (TPAN) in human milk has made an important contribution to further understanding the distribution of nucleosides and nucleotides. This method was applied in a lactation study of bovine milk with colostrum and milk samples collected from two herds over the course of the first month post-partum, pooled within each herd by stage of lactation and the TPAN concentrations were determined. Sample analysis consisted of parallel enzymatic treatments, phenylboronate affinity gel extraction, and liquid chromatography to quantify contributions of nucleosides, monomeric nucleotides, nucleotide adducts, and polymeric nucleotides to the nutritionally available nucleoside pool. Bovine colostrum contained high levels of nucleosides and monomeric nucleotides, which rapidly decreased as lactation progressed into transitional milk. Mature milk was relatively consistent in nucleoside and monomeric nucleotide concentrations from approximately the tenth day post-partum. Differences in concentrations between summer-milk and winter-milk herds were largely attributable to variability in uridine and monomeric nucleotide concentrations. The TPAN method was subsequently applied to the analysis of mature bovine, caprine, and ovine milk. The contributions to TPAN from polymeric nucleotides, monomeric nucleotides, and nucleotide adducts were then calculated. Ovine milk contained the highest concentration of TPAN (374.1 µmol dL-1), with lower concentrations in caprine milk (97.4 µmol dL-1) and bovine milk (7.9 µmol dL-1). Ovine milk contained the highest concentrations of each of the different nucleoside and nucleotide forms, and bovine milk contained the lowest. A method for the simultaneous analysis of nucleosides and nucleotides in infant formula using reversed-phase liquid chromatography-tandem mass spectrometry was developed. Following sample dissolution, protein was removed by centrifugal ultrafiltration. Chromatographic analyses were performed using a C18 stationary phase and gradient elution, with mass spectrometric detection, and quantitation by stable isotope labelled internal standard technique. A single laboratory validation study was performed with recoveries of 80.1–112.9% and repeatability relative standard deviations of 1.9–7.2%. The method was validated for the analysis of bovine milk-based, soy-based, caprine milk-based and hydrolysate-based infant formula

    Monitoring Cl- movement in single cells exposed to hypotonic solution

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    Self-referencing ion--selective electrodes (ISEs), made with Chloride Ionophore I-Cocktail A (Fluka), were positioned 1-3 microm from human embryonic kidney cells (tsA201a) and used to record chloride flux during a sustained hyposmotic challenge. The ISE response was close to Nernstian when comparing potentials (VN) measured in 100 and 10 mM NaCl (deltaVN = 57 +/- 2 mV), but was slightly greater than ideal when comparing 1 and 10 mM NaCl (deltaVN = 70 +/- 3 mV). The response was also linear in the presence of 1 mM glutamate, gluconate, or acetate, 10 microM tamoxifen, or 0.1, 1, or 10 mM HEPES at pH 7.0. The ISE was approximately 3 orders of magnitude more selective for Cl- over glutamate or gluconate but less than 2 orders of magnitude move selective for Clover bicarbonate, acetate, citrate or thiosulfate. As a result this ISE is best described as an anion sensor. The ISE was 'poisoned' by 50 microM 5-nitro-2-(3phenylpropyl-amino)-benzoic acid (NPPB), but not by tamoxifen. An outward anion efflux was recorded from cells challenged with hypotonic (250 +/- 5 mOsm) solution. The increase in efflux peaked 7-8 min before decreasing, consistent with regulatory volume decreases observed in separate experiments using a similar osmotic protocol. This anion efflux was blocked by 10 microM tamoxifen. These results establish the feasibility of using the modulation of electrochemical, anion-selective, electrodes to monitor anions and, in this case, chloride movement during volume regulatory events. The approach provides a real-time measure of anion movement during regulated volume decrease at the single-cell leve

    Author, publisher and bookseller : a tripartite synergy in Nigerian book industry

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    This work is about the roles of Author, Publisher and Bookseller in Book development in Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after which it proceeded by defining who an author, a publisher, and a bookseller is and expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in the emerging Information Society. Furthermore, the various constraints to book development were identified while the paper advised on how the Book Industry can be further promoted in Nigeria. However, the paper concluded and made recommendations on how the Book sector can help in enhancing scholarship in the country

    [Report to Chief J. E. Curry, by an unknown author #2]

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    Report to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney

    [Report to Chief J. E. Curry, by an unknown author #1]

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    Report to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney

    Mining e-mail content for author identification forensics

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    We describe an investigation into e-mail content mining for author identification, or authorship attribution, for the purpose of forensic investigation. We focus our discussion on the ability to discriminate between authors for the case of both aggregated e-mail topics as well as across different email topics. An extended set of e-mail document features including structural characteristics and linguistic patterns were derived and, together with a Support Vector Machine learning algorithm, were used for mining the e-mail content. Experiments using a number of e-mail documents generated by different authors on a set of topics gave promising results for both aggregated and multi-topic author categorisation
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