1,720,960 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

    Aspirin pretreatment potentiates hyperthermia-induced teratogenesis in the mouse

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    OBJECTIVE: Our purpose was to investigate the effect of aspirin pretreatment on hyperthermia-induced teratogenesis. The rationale for the study was based on the growing evidence that prostaglandin pathway may be involved in the cellular response to the thermic injury. STUDY DESIGN: On gestation day 8.5 Swiss mice were treated with 0 or 200 mg/kg of aspirin and 1 hour later exposed to a single 10-minute thermostatic bath treatment at 38 degrees C, 41 degrees C, 42 degrees C, or 43 degrees C. On gestation day 18 uterine contents were evaluated for developmental disorders, including prenatal mortality, intrauterine growth restriction, and external, visceral, and skeletal abnormalities. RESULTS: Consistent with expectations, hyperthermia impaired morphogenesis in a dose-related manner. Although aspirin alone did not reveal embryotoxicity, its administration potentiated hyperthermia-induced teratogenesis. A statistically significant interaction (p < 0.05) was observed at 42 degrees C, where the incidence of fetuses per litter with axial skeletal malformations increased from 20.3% to 55.7%. CONCLUSION: A nonteratogenic dose of aspirin enhanced the teratogenic response to hyperthermia. This result fits the hypothesis that prostaglandins may play a protective role in hyperthermia-induced teratogenesis

    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

    Successful management of a triplet heterotopic caesarean scar pregnancy after in vitro fertilization-embryo transfer.

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    OBJECTIVE: To report a case of a triplet heterotopic caesarean scar pregnancy (CSP) with two gestational sacs implanted in the caesarean scar after in vitro fertilization-embryo transfer. DESIGN: Case report. SETTINGS: Private reproductive medicine center and obstetric department of a university hospital. PATIENT(S): A 31-year-old woman with previous caesarean section affected by secondary infertility related to male azoospermia. INTERVENTION(S): In vitro fertilization-embryo transfer followed by early ultrasound diagnosis of heterotopic CSP and selective embryo reduction performed by transvaginal ultrasound-guided potassium chloride and methotrexate injection in the ectopic gestational sacs. MAIN OUTCOME MEASURE(S): Successful pregnancy outcome. RESULT(S): An ongoing intrauterine pregnancy with a live birth after successful management of ectopic gestational sacs. CONCLUSION(S): Triplet heterotopic CSP with two ectopic gestational sacs may occur after IVF-ET and, to our knowledge, this is the first time such a complication has been reported. Ultrasound is the main tool allowing early diagnosis of this condition, and the injection of potassium chloride and methotrexate is a safe and efficacious treatment method. The gynecologist managing early pregnancy should be aware of the possibility of CSP, and patients must be appropriately counseled about the different treatment options

    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
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