1,720,977 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
Abstract 2047: The muscarinic receptor antagonist, benztropine, blocks the expansion of a temozolomide resistant subpopulation of glioma cells
No full textAbstract
Virtually all malignant gliomas become drug-resistant and recur after initial treatment, recurrent tumors are fatal within two-years, and no therapies exist that cure gliomas. The recognition that subpopulations of primitive cells with an oligodendrocyte precursor-like (OPC-like) phenotype capable of resisting standard therapy and contributing to recurrence, frames the question of whether adjuvant therapies designed to modify or eliminate OPC-like cells could slow the progression of glioma. Agents that force the differentiation of treatment-resistant OPC-like glioma cells, a phenomenon that requires cessation of proliferation, are compelling candidates for targeting OPC-like GSCs. Recently, it was observed that OPC proliferation was driven by activation of the M1, M3 and M4 muscarinic receptors. In another report, a large-scale drug screen designed to seek drugs to induce OPC differentiation in the context of multiple sclerosis identified a muscarinic receptor antagonist, benztropine (a.k.a. Cogentin), as a promoter of OPC differentiation and cell cycle exit. We have conducted studies in glioma cell lines supporting a role for benztropine in suppressing the development of drug-resistance to the standard glioma chemo-therapeutic temozolomide (TMZ). Upon treatment with TMZ, we identified the emergence of an OPC-like subpopulation of glioma cells identifiable by the co-expression of CD44, CD15 and PDGFRa. Treatment with pre-inhibitory doses of benztropine significantly reduced the TMZ IC50 in all glioma lines examined in association with blocking emergence of the CD44/CD15/PDGFR-positive subpopulation. Ongoing studies are designed to determine the tumor initiating potential of the CD44/CD15/PDGFR-positive subpopulation and whether benztropine will suppress the development of TMZ resistance in animal models of glioma.
Citation Format: Damian A. Almiron Bonnin, Joseph M. Howard, Alison L. Young, Mark A. Israel, Matthew C. Havrda. The muscarinic receptor antagonist, benztropine, blocks the expansion of a temozolomide resistant subpopulation of glioma cells [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 2047. doi:10.1158/1538-7445.AM2017-2047</jats:p
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
Abstract 5009: Self-renewal of hypoxic glioma stem-like cells is facilitated by secretion-mediated STAT3 activation
No full textAbstract
Glioblastoma, a type of high-grade glioma, is the most common and the most aggressive primary brain tumor of adults. The median survival is 12-15 months. Despite multimodality treatment, most high-grade gliomas eventually recur and are ultimately incurable. Several studies suggest that the initiation, progression, and recurrence of gliomas are driven at least partly by cancer stem-like cells. A defining characteristic of these cancer stem-like cells is their capacity to self-renew. We have identified a pathway dependent upon tumor hypoxia, a commonly found pathologic feature of GBM, that promotes self-renewal through the HIF1α-JAK1/2-STAT3 axis. Under hypoxic conditions, the expression of HIF1α is greatly increased in GBM stem-like cells leading to the activation of JAK1/2-STAT3 which mediates enhanced tumor stem-like cell self-renewal. Our data further demonstrate the importance of VEGF secretion for this pathway of hypoxia-mediated self-renewal. Using tumor stem-like cells derived from the S100β-v-erbB/p53-/- mouse model of spontaneous high-grade glioma, we have discovered that the activation of STAT3 through hypoxia-mediated VEGF secretion is required for self-renewal of glioma stem-like cells. Media conditioned by these S100β-v-erbB/p53-/- tumor sphere cells cultured under hypoxic conditions promoted self-renewal in S100β-v-erbB/p53-/- glioma stem-like cells and depletion of VEGF from this media was sufficient to inhibit STAT3 phosphorylation. Moreover, we have been able to identify two drugs: Brefeldin A and EHT-1864, that significantly inhibit VEGF secretion, decrease stem cell self-renewal, inhibit tumor growth, and increase the survival of mice allografted with S100β-v-erbB/p53-/- glioma stem-like cells. Cells treated with these drugs express molecular signatures that correlated strongly with the increased survival of GBM patients. These findings suggest a novel treatment strategy to inhibit hypoxia-mediated self-renewal of glioma stem-like cells in high-grade gliomas by targeting the secretion of extracellular, paracrine mediators of self-renewal.
Citation Format: Damian A. Almiron Bonnin, Matthew C. Havrda, Huan Liu, Myung Chang Lee, Matthew H. Ung, Chao Cheng, Mark A. Israel. Self-renewal of hypoxic glioma stem-like cells is facilitated by secretion-mediated STAT3 activation [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 5009. doi:10.1158/1538-7445.AM2017-5009</jats:p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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