1,720,979 research outputs found
Common Fragile Sites: updating the causes of their variability in different cell tissues
Full text linkCommon Fragile Sites (CFSs) are regions in which DNA is prone to gaps, breaks or constrictions visible on metaphase chromosomes when cells are under replicative stressful conditions.
CFSs are characterized by slow/late replication timing mainly due, among other characteristics, to nucleotide sequence which tend to form secondary structure, and to the number of active (or inducible) replication origins. Recent studies indicate that CFSs expression is associated with tissue specificity. In the first part of the work, induction and classification of CFSs in two human lung fibroblast cell line, IMR-90 and MRC-5, has been done. Cytogenetical identification of the most expressed CFSs in both fibroblast cell lines were done: 1p31.1 and 3q13.3, located on chromosome 1 and 3 respectively, are peculiar for this tissue. These regions have typical and confirmed CFSs’ characteristics such as expression higher than 3%, high AT levels and enrichment in large genes.
Using genomic databases, searching for causes of their instability were done comparing percentage of repetitive elements among the CFSs, non-fragile regions (NFRA) and standard genomic sequences. These CFSs are characterized by presence of large genes, NEGR1 found in 1p31.1, LSAMP and ARHGAP31 in the most fragile region of 3q13.3, that could be co-responsible for their genomic instability.
Using probes delimitating fragile regions and combining FISH with IF anti-BrdU, analysis of relationship between replication timing and fragility was done. Furthermore, comparison between replication timing, in normal and stressful condition using APH, was done as well. The results obtained for these fragile regions reflect the replication timing impairments typical of fragile sites, in both normal and stressful conditions.
The same probes when used in lymphocytes result in a normal replication timing, moreover also using CFSs probes specific in lymphocytes on fibroblast, results in normal replication timing.
The results from replication timing analysis are strictly correlated with the structural and functional characteristics that are specific of the tissues in which these CFSs are expressed
Aneuploidy studies in natural populations of rodents to monitor environmental contamination.
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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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