1,720,966 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
An angiomatoid fibrous histiocytoma over the left pre auricular region in a 13-year-old boy.
No full textA 13-year-old boy presented to us for the evaluation of a slowly growing mass over the left preauricular region. Physical examination showed a nodular swelling, firm on palpation. The patient had no lymphadenopathy. The findings of magnetic resonance imaging (MRI) and vascular MRI led us to suspect a vascular growth. An incisional biopsy was performed and revealed an angiomatoid fibrous histiocytoma (AFH). Angiomatoid fibrous histiocytoma (AFH) is a rare tumor of the soft tissue with fibrohistiocytic and vascular differentiation that shows an intermediate malignancy grade, mainly occurs in patients younger than 20 years of age, and is usually localized on the extremities. Angiomatoid fibrous histiocytoma is considered to be a tumor of intermediate malignancy because of its less aggressive course in contrast to conventional malignant fibrous histiocytoma (MFH). Our case of AFH is peculiar because of its localization in the pre auricular region and because it appeared in a young patient. Surgical excision with maxillo-facial, chest-abdomen, and neck CT and prolonged follow-up is recommended because rare cases of metastasizing AFH have been reported
Intra-articular venous malformations of the knee.
No full textBackground: Intra-articular venous malformations (IAVM) of the knee represent a rare group of low-flow vascular malformations, mainly reported in the literature as synovial hemangiomas, usually with an onset in early childhood. The main symptoms and signs are knee pain, swelling, and hemarthrosis. These lesions are slowly progressive and can lead to chronic synovitis and joint damage. Confusing nomenclature and classification of these lesions have often led to misdiagnosis and inappropriate treatment. We report our experience in the treatment of 14 consecutive patients affected by knee IAVM. Methods: We carried out a retrospective study based on the review of the medical records and diagnostic imaging of the patients admitted to our department from October 1999 to June 2009, and discharged with the final diagnosis of IAVM of the knee. Results: We observed 14 consecutive patients (8 boys, 6 girls); the median age at symptom onset was 5 years (range, 2.5 to 13 y). Magnetic resonance imaging was diagnostic in all cases. Surgical resection associated with a wide synoviectomy was the therapeutic procedure of choice in all cases. Within 6 months after surgery and physiotherapy, all the patients were symptom free with a full or at least acceptable knee range of motion. CD34 staining carried out in the last 7 cases of our series showed labeling of the endothelium of the thick-walled vessels, whereas the endothelium of the thin-walled vascular spaces was not stained. This finding of unstained vascular spaces suggests that a component of lymphatic vessels mixed with dysplastic blood vessels may be frequently present in these abnormalities. Conclusions: Magnetic resonance imaging plays a pivotal role in identifying the lesion. Surgical excision is always indicated and should be performed as early as possible to avoid lesion progression and to reduce the risk of chondral degeneration. According to the microscopic features of our resected specimens, we suggest that these lesions of the knee should be more properly named as IAVM instead of hemangiomas
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