1,720,966 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

    Use of erythropoietin in oncology

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    Anemia is a common complication observed in cancer patients. Its etiology is multifactorial and its severity depends on patient characteristics, type and stage of neoplasia, type of used chemotherapy. Erythropoietin can be effective by counteracting two of the main causes of anemia in cancer patients undergoing chemotherapy: 1. Myelosuppression induced by chemotherapy. Almost all cytotoxic drugs induce this effect. In this circumstance erythropoietin can be effective by accelerating the recovery of the erythroid compartment spared by chemotherapy. For this effect, higher than physiologically normal levels of erythropoietin are required. 2. Endogenous erythropoietin deficiency secondary to renal impairment. Renal impairment is primarily induced by cisplatin and leads to a deficient renal production of erythropoietin. In this case, erythropoietin administration can be considered as a hormone replacement therapy. Possible indications for the use of erythropoietin in cancer patients are the following: 1. Prevention of anemia; 2. Treatment of anemia induced by either high dose chemotherapy and bone marrow transplantation (BMT) or standard dose chemotherapy. The preventive use of erythropoietin is still under investigation. Two randomized studies reported the erythropoietin ability to prevent the anemia development. Further trials are required to identify subsets of patients in which the preventive use of the drug could be cost-effective. One of the causes of anemia after allogeneic BMT is the endogenous production of erythropoietin inappropriately low for the degree of anemia. On the contrary, after autologous BMT the erythropoietin response to anemia is appropriate. Phase III randomized studies showed the efficacy of erythropoietin in the treatment of anemia after allogeneic but not after autologous BMT. After standard dose chemotherapy, phase III randomized studies showed that erythropoietin is able to correct anemia in 60-80% of patients receiving platinum-based chemotherapy and in nearly 40% of patients receiving chemotherapy without platinum. The correction of anemia leads to a significant reduction in transfusion requirement. In solid tumors erythropoietin is commonly administered at the schedule of 150 U/Kg subcutaneously three times per week. Normal levels of current iron supply should be guaranteed by oral iron support during erythropoietin treatment. Because the response to erythropoietin occurs after a median time of 5 weeks, it is necessary to start erythropoietin therapy at an hemoglobin level higher than that triggering transfusion. Various parameters, at baseline or after 2-4 weeks of erythropoietin therapy, have been evaluated as predictors of response. However, other parameters should be studied to identify stronger predictors. Conclusions. Erythropoietin treatment is recommended after allogeneic BMT. Erythropoietin is effective in 60-80% of anemic patients receiving platinum-containing chemotherapy and in approximately 40% of patients receiving chemotherapy without platinum. The preventive use of erythropoietin is still under investigation. Further studies should identify subsets of patients and types of chemotherapy in which the prevention of anemia could be cost/effective

    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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