1,721,343 research outputs found
Multi-Omics Approach to Mitochondrial DNA Damage in Human Muscle Fibers
Abstract: Mitochondrial DNA deletions affect energy metabolism at tissue-specific and cell-specific
threshold levels, but the pathophysiological mechanisms determining cell fate remain poorly understood.
Chronic progressive external ophthalmoplegia (CPEO) is caused by mtDNA deletions and
characterized by a mosaic distribution of muscle fibers with defective cytochrome oxidase (COX)
activity, interspersed among fibers with retained functional respiratory chain. We used diagnostic
histochemistry to distinguish COX-negative from COX-positive fibers in nine muscle biopsies from
CPEO patients and performed laser capture microdissection (LCM) coupled to genome-wide gene
expression analysis. To gain molecular insight into the pathogenesis, we applied network and
pathway analysis to highlight molecular differences of the COX-positive and COX-negative fiber
transcriptome. We then integrated our results with proteomics data that we previously obtained
comparing COX-positive and COX-negative fiber sections from three other patients. By virtue of
the combination of LCM and a multi-omics approach, we here provide a comprehensive resource
to tackle the pathogenic changes leading to progressive respiratory chain deficiency and disease in
mitochondrial deletion syndromes. Our data show that COX-negative fibers upregulate transcripts
involved in translational elongation and protein synthesis. Furthermore, based on functional annotation
analysis, we find that mitochondrial transcripts are the most enriched among those with
significantly different expression between COX-positive and COX-negative fibers, indicating that
our unbiased large-scale approach resolves the core of the pathogenic changes. Further enrichments
include transcripts encoding LIM domain proteins, ubiquitin ligases, proteins involved in
RNA turnover, and, interestingly, cell cycle arrest and cell death. These pathways may thus have a
functional association to the molecular pathogenesis of the disease. Overall, the transcriptome and
proteome show a low degree of correlation in CPEO patients, suggesting a relevant contribution of
post-transcriptional mechanisms in shaping this disease phenotype
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
We 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
We 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.
Author-wise bibliometric analysis based on entropy.</p
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