1,721,076 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

    Non-anaplastic pleomorphic xanthoastrocytoma with neuroradiological evidences of leptomeningeal dissemination

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    CASE REPORT: A case of a non-anaplastic pleomorphic xanthoastrocytoma (PXA) presenting with leptomeningeal dissemination (LMD) affecting a 9-year-old girl is presented. DISCUSSION: The neoplasia in this young girl had the otherwise classical clinical features of PXA: the relatively advanced paediatric age of the patient, the seizures as presenting sign; the primary site in the temporal lobe; and the MRI findings of the partially solid and cystic superficial lesion. Only the tumour involvement of the chiasma and the infundibulus was a relatively unusual finding. In a 5-year period, the tumour underwent malignant transformation, bringing the child to death because of the primary tumour progression. However, the leptomeningeal deposits remained unchanged throughout the clinical course. CONCLUSION: To our knowledge, this is the first case of a non-anaplastic PXA presenting with disseminated disease. Thus, it was thought important to describe this case in order to add further information regarding the spectrum of the presenting clinical features of this rare neoplasm and the phenomenon of LMD of non-malignant glioma

    Hyperfractionated radiotherapy and chemotherapy for childhood ependymoma: final results of the first prospective AIEOP study Internat.

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    PURPOSE: A postsurgical "stage-based" protocol for ependymoma was designed. METHODS AND MATERIALS: Children were given: (1) focal hyperfractionated radiotherapy (HFRT) if with no evidence of disease (NED), or (2) 4 courses with VEC followed by HFRT for residual disease (ED). HFRT dose was 70.4 Gy (1.1 Gy/fraction b.i.d.); VEC consisted of VCR 1.5 mg/m2 1/w, VP16 100 mg/m2/day x 3, CTX 3 g/m2 d 1. When feasible, second-look surgery was recommended. RESULTS: Sixty-three consecutive children were enrolled: 46 NED, 17 ED; the tumor was infratentorial in 47 and supratentorial in 16, with spinal metastasis in 1. Of NED patients, 35 of 46 have been treated with HFRT; 8 received conventionally fractionated radiotherapy, and 3 received no treatment. Of the 17 ED patients, 9 received VEC + HFRT; violations due to postsurgical morbidity were as follows: HFRT only (2), conventionally fractionated radiotherapy (3) + VEC (2), and no therapy (1). Objective responses to VEC were seen in 54%; objective responses to RT were seen in 75%. Overall survival and progression-free survival at 5 years for all 63 children were 75% and 56%, respectively; for the NED subgroup, 82% and 65%; and for the ED subgroup, 61% and 35%, respectively. All histologies were centrally reviewed. At multivariate analysis, grading, age, and site proved significant for prognosis. CONCLUSIONS: HFRT, despite the high total dose adopted, did not change the prognosis of childhood ependymoma as compared to historical series: New radiotherapeutic approaches are needed to improve local control. Future ependymoma strategies should consider grading when stratifying treatment indications
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