1,721,040 research outputs found
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
Dispelling the Myths Behind First-author Citation Counts
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
Nodular renal blastoma in kidney with multicystic dysplasia. Report of a case.
The clinico-pathologic association of nodular renal blastema, multicystic kidney and obstructive uropathy has been recently identified. We report on a female patient diagnosed as having unilater multicystic dysplasia by prenatal ultrasonography. The patient was nephrectomized at the age of 6 1/2 months. Examination of the resected kidney revealed multiple unilocular cysts in the cortex and hypoplasia of the homolateral ureter; histological study confirmed the presence of multiple cysts limited to the renal cortex, and revealed, among them, multiple cortical metanephric blastema cells islands. Our case supports a relationship between nodular renal blastema, cortical cysts and obstructive uropathy; ureter hypoplasia could cause intraluminal back pressure, with consequent abnormal development of the ampullae, normally endowed in nephronic anlagens induction, cystic tubular ectasia and persistence of nodular renal blastema. The peripheral location of renal nodular blastema and cysts supports a late error in nephrogenesis, at the time of formation of the last generation of nephrons
Evidence for a hybrid macrophage phenotype in erythrophagocytic histiocytosis
PURPOSE: The phenotype of the proliferating cells in two patients with erythrophagocytic histiocytosis is described. These 6- and 18-month-old female patients presented with fever, anemia, hepatosplenomegaly, and lymphadenopathy. MATERIALS AND METHODS: Clinical histories were reviewed, and pathological specimens of both patients were studied by histology, and electron microscopy/immunohistochemistry using antibodies against macrophage and Langerhans cell (LC) antigens. RESULTS: Histology revealed prominent erythrophagocytosis of proliferating histiocytes. By immunohistochemistry, conventional macrophage (HAM-56, alpha 1-antitrypsin, alpha 1-antichymotrypsin, lisozyme, CD68, and alpha-subunit of S-100 protein) and LC (CD1a and S-100 protein) markers were positive, as well as double labeling for CD1a and alpha 1-antichymotrypsin, in a majority of proliferating cells. Ultrastructural examination revealed Birbeck granules and prominent phagolysosomes frequently in the same cell. CONCLUSIONS: The hybrid ultrastructural and immunohistochemical phenotype between phagocytic macrophage and LC of proliferating histiocytes supports the common origin of these different histiocyte subtypes. This unusual phenotype might be the expression of the proliferating (hybrid) precursor or be the effect of unknown stimuli. Additional cases of childhood erythrophagocytic histiocytosis should be studied with immunophenotyping and ultrastructure to determine whether the hybrid phenotype represents a specific entity or an epiphenomenon
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