1,720,969 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

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used

    Evalutation of mycophenolic acid systemic exposure by limited sampling strategy in kidney transplant recipients receiving enteric-coated mycophenolate sodium (EC-MPS) and cyclosporine.

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    Background. Enteric-coated mycophenolate sodium (EC-MPS) and mycophenolate mofetil (MMF) are prodrugs of mycophenolic acid (MPA). Although many patients still receive MMF as an inosine monophosphate dehydrogenase inhibitor, EC-MPS could be considered a reliable alternative to MMF in the immunosuppressive protocols of kidney transplant recipients. MPA shows high pharmacokinetic variability and consequently a 12-h area under the curve (AUC0-12) should be used to guide the therapeutic dosage. However, patient compliance and economic costs make MPA AUC0-12 an unpractical approach. Limited sampling strategies or predictive systemic drug exposure equation models based on limited sampling times are available only for MMF but lack for EC-MPS.Methods. The present study enrolled 26 kidney transplant recipients receiving EC-MPS as part of their immunosuppressive therapy. Twenty-six full MPA AUC0-12 were performed. By using multiple stepwise regression analysis, we obtained several predictive equations of MPA systemic exposure in this group of patients. The value of the selected equations was tested in a subsequently enrolled group of 26 kidney transplant recipients.Results. The best equations obtained in the first group of patients were the following: 22.906 + 3.880·C0 + 1.117·C1 + 7.527·C8 (r = 0.901) and 35.064 +3.784·C0 + 1.002·C1 + 1.192·C2 (r = 0.846). These equation models showed an optimal agreement between the full AUCs and estimated AUCs by using the validation group of patients.Conclusions. Limited sampling strategies are useful for MPA AUC0-12 estimation in patients receiving EC-MPS and cyclosporine. The choice of one or the other equation model depends on the pharmacokinetic characteristics of the patients, in particular the potential presence of enterohepatic recirculation

    Reliability of total overnight salivary caffeine assessment (TOSCA) for liver function evaluation in compensated cirrhotic patients

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    BACKGROUND AND AIMS: Systemic caffeine clearance is considered the gold standard for phenotyping cytochrome P450 1A2 in epidemiological studies, and has been recommended for the non-invasive assessment of liver function in chronic liver disease. Our aim was to find a valid, simple and reliable alternative to this method, and therefore focused our attention on the measurement of an unique salivary caffeine concentration, without drug exposure. METHODS: Our evaluation included 36 healthy controls, 47 patients with compensated liver cirrhosis of viral origin, and 48 obese and diabetic patients with cryptogenetic (likely metabolic) cirrhosis. All shared the same caffeine consumption habits (regular daily use of caffeinated beverages, mainly coffee). The total overnight salivary caffeine assessment (TOSCA) was determined by using a single-point concentration of salivary caffeine, after an overnight period of abstinence. RESULTS: Daily routine caffeine intake of our population was adequate for studying the TOSCA. This single-point concentration correlated well with caffeine clearance, measured by salivary concentrations of caffeine. Mean TOSCA in cirrhotic patients was significantly higher than in controls (p<0.001; sensitivity (%) 84.2 and specificity (%) 97.2; negative likelihood ratio=0.16 and positive likelihood ratio=30.32). A cut-off set at 4.2 microg/ml (sensitivity (%) 95.8 and specificity (%) 68.1; negative likelihood ratio=0.06 and positive likelihood ratio=3.0) successfully differentiated the type of cirrhosis. Rapid (with higher metabolism of caffeine) metabolizers were more frequent in the group of patients with cirrhosis of metabolic origin (70.8%; p<0.0001), and the opposite was true for the group of patients with cirrhosis of viral origin, which comprised many poor metabolizers (85.1%; p<0.001). Serum transforming growth factor-beta 1 concentration, mirroring ongoing fibrosis, ranked high in poor metabolizers. The association between overnight assessment and homeostasis model assessment in rapid metabolizers could result from similar roles for cytochrome P450 1A2 and insulin resistance in determining metabolic liver cirrhosis. CONCLUSION: The TOSCA, although differential between the viral and metabolic etiologies, could be considered a good diagnostic use to verify the presence and eventually the type of compensated liver cirrhosis
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