1,720,963 research outputs found
The facilitative role of the extracellular matrix in the development of colorectal cancer liver metastases
No full textWe have investigated the hypothesis that a desmoplastic reaction (DR), characterised by the deposition of collagens I and III produced by activated stromal cells, offers Colorectal Cancer (CRC) liver metastases a growth and survival advantage. Immunohistochemical staining of liver specimens obtained at resection for CRC, demonstrated increased deposition of fibrillar collagens and alterations in collagen IV distribution within the tumour as part of a DR. In addition, the deposited fibrillar collagens were closely associated with increased numbers of activated hepatic stellate cells/myofibroblasts. Β1 integrins were highly expressed by both cancer and stromal cells throughout the tumour stroma. However, in poorly differentiated areas of the CRC metastases β1 integrins appeared to be down-regulated, with αv integrin (especially αbβ5) expression upregulated. Clonogenic (survival) and PARP cleavage (apoptosis) assays, showed that collagen I compared to collagen IV significantly increased the survival and reduced the rate of cellular apoptosis for CRC treated with chemotherapy (5-Fluorouracil). The adhesion and proliferation of CRC cells on collagens I and IV was significantly reduced in a dose dependent manner, after incubation with β1 integrin neutralising antibodies (5-10μg/ml), compared to IgG controls. In contrast, αvβ3 and αvβ5 neutralising antibodies (5-20μg.ml), had no influence on the CRC cell adhesion, but significantly reduced the rate of proliferation of the CRC cell lines on collagens, especially for the highly metastatic KM12SM cell line. These results support a role for the desmoplastic reaction in supporting CRC metastases, mediated via β1 and αv integrins. As CRC adopt a more aggressive malignant phenotype, matrix turnover reveals specific binding epitopes which upon ligation by αv integrins plays a key growth regulatory role.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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