1,720,995 research outputs found
Melanotic neuroectodermal tumor of the epididymis in infancy: case report and review of the literature.
Melanotic neuroectodermal tumor of infancy (MNTI) is a rare, benign tumor that usually involves the upper or lower jaw, but it may also arise in other sites. We describe a case of MNTI located in the left epididymis of a 6-month-old boy. Left orchiectomy was performed. Immunohistochemical and ultrastructural studies revealed two types of cells: small, poorly differentiated cells that were positive for neuron-specific enolase protein and vimentin, and larger epithelial cells that were positive for melanoma antigen (HMB45) and frequently contained large and elongated melanosomes, similar to those described in retinal pigmented epithelium. At 12 months of follow-up, no recurrences or metastases were seen. Primary involvement of the epididymis has been previously reported in only 16 cases. Immunohistochemical and ultrastructural studies suggest that the neoplasm is of neural crest origin
Sulle possibilita' d'impiego delle saldature per punti nella carpenteria metallica ordinaria
Going Beyond Counting First Authors in Author Co-citation Analysis
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
“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
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
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