1,721,021 research outputs found
DNA damage signaling in response to double-strand breaks during mitosis
Full text linkThe signaling cascade initiated in response to DNA double-strandx breaks (DSBs) has been extensively investigated in interphase cells. Here, we show that mitotic cells treated with DSB-inducing agents activate a "primary" DNA damage response (DDR) comprised of early signaling events, including activation of the protein kinases ataxia telangiectasia mutated (ATM) and DNA-dependent protein kinase (DNA-PK), histone H2AX phosphorylation together with recruitment of mediator of DNA damage checkpoint 1 (MDC1), and the Mre11-Rad50-Nbs1 (MRN) complex to damage sites. However, mitotic cells display no detectable recruitment of the E3 ubiquitin ligases RNF8 and RNF168, or accumulation of 53BP1 and BRCA1, at DSB sites. Accordingly, we found that DNA-damage signaling is attenuated in mitotic cells, with full DDR activation only ensuing when a DSB-containing mitotic cell enters G1. Finally, we present data suggesting that induction of a primary DDR in mitosis is important because transient inactivation of ATM and DNA-PK renders mitotic cells hypersensitive to DSB-inducing agents. © 2009 Giunta et al
Give me a break, but not in mitosis
No full textDNA double-strand breaks (DSBs) are extremely cytotoxic lesions with a single unrepaired DSB being sufficient to induce cell death. A complex signaling cascade, termed the DNA damage response (DDR), is in place to deal with such DNA lesions and maintain genome stability. Recent work by us and others has found that the signaling cascade activated by DSBs in mitosis is truncated, displaying apical, but not downstream, components of the DDR. The E3 Ubiquitin ligases RNF8, RNF168 and BRCA1, along with the DDR mediator 53BP1, are not recruited to DSB sites in mitosis, and activation of downstream checkpoint kinases is also impaired. Here, we show that RNF8 and RNF168 are recruited to DNA damage foci in late mitosis, presumably to prime sites for 53BP1 recruitment in early G1. Interestingly, we show that, although RNF8, RNF168 and 53BP1 are excluded from DSB sites during most of mitosis, they associate with mitotic structures such as the kinetochore, suggesting roles for these DDR factors during mitotic cell division. We discuss these and other recent findings and suggest how these novel data collectively contribute to our understanding of mitosis and how cells deal with DNA damage during this crucial cell cycle stage. © 2011 Landes Bioscience
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
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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