1,720,987 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
Reverse transcription polymerase chain reaction phenotyping of metalloproteinases and inhibitors involved in tumor matrix invasion.
No full textI.F. 2.795
Abstract: The matrix metalloproteinase enzymes have been implicated in tumor invasion and metastasis by a series of correlative immunohistochemical studies. In addition, direct evidence for the role of these enzymes in this pathologic process comes from studies using specific metalloproteinase inhibitors to block tumor invasion and metastasis formation, both in vitro and in vivo. Synthetic oligonucleotide primers for four metalloproteinases (MMP-1, MMP-2, MMP-9, MMP-10) and their tissue inhibitors (TIMP-1, TIMP-2) were selected, synthesized, and optimized in the reverse transcriptase-polymerase chain reaction (RT-PCR) to study the qualitative profile of these enzymes and inhibitors in cultured human tumor cells and tumor tissues. These primers are specific and generate unique amplification products for each appropriate enzyme and inhibitor. Slight enhancement in the amplification of cDNA products was achieved by adding dimethylsulfoxide to the reaction mixture, but commercial enhancement reagents were ineffective. Using this RT-PCR method, cDNA amplification was successful with RNA from as few as 20 cultured tumor cells. The RT-PCR analysis was done on three invasive human colon adenocarcinomas and their paired adjacent normal mucosa. The results show MMP-1 and MMP-2 products in all three tumors, and MMP-2 detected in one of the three normal mucosa samples; TIMP-2 expression was present in two of three patients and awaits quantitative assessment of RT-PCR product
Natural and synthetic agents targeting inflammation and angiogenesis for chemoprevention of prostate cancer
No full textProstate cancer is the most common cancer in men and one of the leading causes of cancer-related deaths in Western countries. The extraordinary biological heterogeneity, the increasing incidence of this disease, and the presence of putative premalignant conditions make prostate cancer a crucial pathology to study and test pharmacological or nutritional chemopreventive strategies. It has been demonstrated that the incidence of prostate cancer is lower in Asian people, and that it increases in Asian men living in Western countries; these data point to a pivotal role of diet in the onset of prostate cancer. A large amount of work has been done in investigating chemopreventive properties of dietary compounds widely used in Asian countries (i.e. soy, soybeans, green tea, fish) in respect of the oxidants- and meat-rich diet typical of Western people, particularly of central and northern Europe. Some dietary products appear promising as chemopreventive agents for prostate cancer, because they display both anti-oxidant and anti-inflammatory activity -and inflammation is crucial for the aetiology of adeno-carcinoma of the prostate. There is increasing evidence for close correlation between inflammation, the microenvironment and tumour-associated neo-angiogenesis causing the adverse outcomes of prostate cancer. It may thus be useful to develop new strategies to couple the treatment of inflammation-related prostate cancer and the generation of angiopreventive or antiinflammatory molecules to prevent this disease. The search for compounds with few or no adverse effects - particularly cardiovascular - as compared with the agents currently in use is therefore of greatest relevance. This paper reviews the beneficial effects in this context of the most promising compounds: beta-carotene, capsaicin, curcumin, daidzein, EGCG, genistein, hyperforin, lycopene, N-acetyl-L-cysteine, reductase inhibitors, resveratrol, selenium, silybinin, quesrcetin, vitamin-D and vitamin-E
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
RENAL MATRIX METALLOPROTEASE MMP2 AND ITS SPECIFIC INHIBITOR TIMP2 IN EXPERIMENTAL DIABETIC NEPHROPATHY AND THE EFFECT OF HEPARIN
No full textMetastatic capacity and differentiation in murine melanoma cell lines. A morphometric study.
No full textA morphometric analysis was carried out on electron micrographs of cells of the F1 (low metastatic capacity) and F10 (high metastatic capacity) variant sublines of the murine B16 melanoma, both in in-vitro cultures and in lung-metastatic nodules developed after the intravenous injection of neoplastic cells in syngeneic C57 black male mice. A group of 28 morphometric parameters was derived to describe quantitatively each neoplastic cell profile. No qualitative difference was observed between the two cell lines. The quantitative expression of subcellular organelles was dissimilar in the two sublines, being consistently characterized, both in in-vitro cultured cells and in lung-metastatic colonies, by a significant decrease in the mean values of parameters related to melanosomes in the high metastatic capacity cell line (B16-F10). Moreover, in in-vitro cultured cells, indices describing heterochromatin masses and cytoplasmic membranous compartments displayed statistically significant differences between the two sublines. In this experimental system, an inverse relationship between metastatic capacity and differentiation is detected, since cells with a more aggressive metastatic behavior exhibit a decreased degree of differentiation
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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