1,720,958 research outputs found
Carbonic anhydrase activity in mammalian retina. Developmental aspects in altricial and precocial species
No full textCarbonic anhydrase activity has been studied during retina development in 2 mammalian species, guinea pig and rat, which differ for birth time and gestational period as being precocial and altricial respectively. For both species, the definitive pattern of enzyme distribution corresponds to the localization of the reaction product in the Müller glial cells at the level of nucleus, perikaryon, lateral processes, and end-feet. Only in the rat retina, staining has been observed also in some amacrine cells. The results of either in situ or extra situm investigations showed that, according to tissue maturity, in the precocial species, the definitive expression of carbonic anhydrase is reached at birth time. In the altricial species, on the contrary, maturity is very delayed and may be recognized at only the 12th d of postnatal life. Present findings confirm that carbonic anhydrase is a marker for the maturity of the retinal glial cells
Prostatic Intraepithelial Neoplasia - Qualitative and Quantitative-analyses of the Blood Capillary Architecture On Thin Tissue-sections.
No full textThe aim of our study was to qualitatively and quantitatively investigate the capillary architecture on lectin Ulex Europaeus agglutinin I-stained histological section in prostatic intra-epithelial neoplasia. The capillaries appeared as small, short or elongated vessels with either a smooth or undulated external contour and either virtual or visible lumen, sometimes with a clearly identifiable endothelial nucleus/i. In the benign prostatic hyperplasia and prostatic intra-epithelial neoplasia categories, the capillaries appeared located in close contact with (i.e. touching) or in proximity to the basement membrane of ducts and acini. In the invasive adenocarcinoma category, on the contrary, the capillaries in general appeared interspersed within the tumour stroma and septa. Our quantitative studies of the capillary architecture showed that, going from benign prostatic hyperplasia through prostatic intra-epithelial neoplasia up to invasive adenocarcinoma, an increasing proportion of capillaries becomes shorter, with open lumen and undulated external contour and with a greater number of endothelial cells. The highest proportion of touching capillaries was seen in benign prostatic hyperplasia, while the lowest was in invasive adenocarcinoma, being intermediate in prostatic intra-epithelial neoplasia. When the prostatic intra-epithelial neoplasia samples were divided into low-grade and high-grade, the feature values in the low-grade approached those in benign prostatic hyperplasia, whereas in the high-grade they were close to invasive adenocarcinoma. Half of the benign prostatic hyperplasia samples were taken from total prostatectomies because of the preoperative diagnosis of prostatic adenocarcinoma. The feature values in this subcategory were close to those of prostatic intra-epithelial neoplasia of low grade
Immunohistochemical localization of intracellular and extracellular associated TGFb in the skin of patients with systemic sclerosis (scleroderma) and primary Raynaud's phenomenon
No full text
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
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