1,721,107 research outputs found
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
Abstract 1345: Mutant IDH1 and tissue factor in gliomas
No full textAbstract
Background: IDH1 mutations (IDH1mut) occur in 20-30% of gliomas, induce DNA hypermethylation, and are associated with a better prognosis than IDH1 wild-type (IDH1wt) gliomas, yet the basis for this remains unclear. Furthermore, venous thromboemboli (VTE) are a serious complication in glioma patients, and the mechanism for this is also unclear. We recently discovered that IDH1mut gliomas are much less likely to develop VTE compared to IDH1wt gliomas. Our data suggests that suppression of Tissue Factor (TF), the primary initiator of coagulation, is a key reason for this. TF also directly enhances tumor malignancy via protease-activated receptor 2 (PAR2). In this study, we further explored the significance of TF on malignancy and thrombosis in IDH1wt and IDH1mut gliomas.
Methods: Assays were performed using 6 patient derived glioma cells, 3 IDH1wt (GBM6, GBM12, GBM43) and 3 IDH1mut (TB09, BT142, GBM164). DNA methylation was analyzed by Illumina Human 850K. TF procoagulant activity (PCA) was determined by FXa generation, using preoperative glioma patient arterial plasma, conditioned medium, or cells. In vivo models of cancer induced thrombosis were created via surgical stenosis of the inferior vena cava of mice engrafted with IDH1wt or IDH1mut gliomas. In vitro markers of malignancy were measured by BrdU incorporation for cell proliferation, serum gradient Matrigel-coated transwell inserts for invasion, soft agar colony formation for clonogenicity. Nude mice (N≥6/group) were orthotopically transplanted with IDH1wt glioma cells and monitored for growth using bioluminescence imaging.
Results: The TF gene, F3, was significantly hypermethylated in IDH1mut cells compared to IDH1wt cells, and IDH1mut glioma cells had lower levels of TF protein and TF PCA compared to IDH1wt cells. Exogenous treatment with the product of IDH1mut enzyme, D-2-hydroxyglutarate, directly suppressed TF PCA by 38% in IDH1wt cells (P=0.03), as did transgene IDH1mut expression. Mice with IDH1mut glioma xenografts produced fewer and smaller IVC thrombi than mice with IDH1wt xenografts (0.9±0.9 vs 10.3±3.6 mg, P=0.02). Patients whose gliomas contained IDH1mut had lower TF PCA compared to IDH1wt (0.5±0.2 vs 1.2±0.2 pg/mL, P=0.04), and there was a strong link between levels of TF PCA and subsequent development of VTE (P=0.03). TF knockdown greatly reduced cell proliferation, invasion, and colony formation of IDH1wt cells. Likewise, the PAR2 antagonist, GB83, inhibited IDH1wt cell proliferation by 54% (P<0.001) and reduced cell invasion by 25% (P<0.05). TF knockdown also reduced in vivo growth of IDH1wt gliomas by 96% at 28 days post engraftment (P=0.03), and extended median survival of engrafted mice by 86% (P=0.001).
Conclusions: IDH1mut mediated suppression of TF expression and PCA may be a critical component of the less thrombogenic, and less malignant, IDH1mut phenotype. Targeting TF-PAR2 signaling may therefore represent a novel therapeutic strategy to reduce IDH1wt glioma malignancy.
Citation Format: Dusten Unruh, Snezana Mirkov, Charles D. James, Craig Horbinski. Mutant IDH1 and tissue factor in gliomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1345. doi:10.1158/1538-7445.AM2017-1345</jats:p
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
- …
