1,721,151 research outputs found
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
Next generation sequencing approaches to identify novel susceptibility genes for epithelial ovarian cancer
Full text linkOvarian cancer is the fifth most common cancer in women in developed countries and is associated with poor survival due to late diagnoses. Strategies focusing on detecting the disease in the earliest stages and/or improving risk prediction may represent effective clinical intervention reducing disease burden. Women at the greatest risk of epithelial ovarian cancer (EOC) can be offered prophylactic risk-reducing salpingo-oopherectomy (RRSO), which is currently only offered to women with mutations in the highly penetrant susceptibility genes BRCA1 or BRCA2. Previous studies show that 46% of familial cases of EOC carry a deleterious mutation in BRCA1 (37%) or BRCA2 (9%). The residual proportion of familial risk is likely to be attributable to other genetic variants providing a rationale for identifying additional susceptibility alleles using rapid high-throughput next generation sequencing (NGS) in large samples sizes. A pilot study determines the principle of NGS in mutation detection sequencing BRCA1 gene in 12 DNA samples with known mutations. The 11bp deletion, missed in the analysis, is detected by altering the bioinformatics. The second study sequences 1506 cases and 1130 healthy controls using Fluidigm microfluidic technology and Illumina HiSeq2000 in 6 DNA repair genes (RAD51B, RAD51C, RAD51D, XRCC2, XRCC3 and SLX4). 94% of the targeted region is sequenced with >30 reads. 23 cases and 1 control show a putative protein-truncating variant in 5 genes. Many missense variants are detected in cases and controls suggesting these are not pathogenic. Epidemiological data shows that women with family history and a deleterious mutation develop EOC on average 10 years younger. Interestingly, half of those women with detected mutations have no family history. A final study uses the established NGS approach to characterise the mutation prevalence in 4 known and 5 candidate EOC susceptibility genes in 2300 unaffected women from high-risk breast-ovarian cancer families. BRCA1 and BRCA2 deleterious mutations are identified in 53 and 49 women respectively. Deleterious mutations are detected in 6 additional genes, BRIP1 (n=5), RAD51C (n=3), RAD51D (n=1) PALB2 (n=5), BARD1 (n=1) and NBN (n=3). Importantly, a bioinformatics pipeline is refined to maximise variant detection sensitivity with zero false negatives where read depth is >30X. Further large case-control studies are recommended to examine the population frequencies in these novel genes. These studies demonstrate the potential of targeted NGS approaches for population-wide risk prediction and early detection of EOC
Functional analysis of low-moderate risk susceptibility genes emerging from pathway based approaches and genome wide association studies in epithelial ovarian cancer
Full text linkPathway based and genome wide association studies aim to identify alleles of low/moderate risk that may account for the development of EOC not attributed to high risk susceptibility genes. The aim of this study was to investigate the functional role of low/moderate susceptibility SNPs and candidate genes that emerge from candidate gene approaches and GWAS using tumour tissues or appropriate models from the proposed cells of origin for EOC, normal Ovarian Surface Epithelium (NOSE), Fallopian Tube Epithelium (FTE) respectively. Part of this study focused in establishing NOSE, FTE and EOC cell lines to study differential expression of candidate genes in post-GWAS functional characterisation studies. Additionally, I have established 3D FTE cultures and propose they more closely resemble the in vivo characteristics than 2D cultures. A candidate gene approach has identified nine candidate genes. I tested 301 invasive EOC tumours and found frequent LOH for tagging SNPs in those genes. LOH was associated with worse survival for AXIN2, CASP5, RRBBP8 and AIFM2 but the result for AXIN2, CASP5 and AIFM2 were associated with stage. Additionally, one SNP in STAG3 showed significant preferential loss of the common allele. Six loci containing susceptibility SNPs were identified in an ovarian cancer GWAS. I found compelling evidence for the somatic role of several genes within these loci in EOC development based on their differential expression between normal (NOSE & FTE) and EOC cell lines. These genes included PVT1, SP2, CBX1, PNPO, HAUS8, USE1, SKAP1, MERIT40 and members of the HOXB family of genes with an observed gain of function role and TIPARP and BNC2 with an observed loss of function role in EOC development. Additionally, I found weak associations of susceptibility SNPs’ genotypes with CBX1, SNX11, SP2 and HOXD1 expression and compelling evidence of genotype specific methylation of HOXB5 using non tumour samples. I further knocked down MERIT40 in EOC cell lines to study the potential role of the gene in EOC development. I found that MERIT40 depletion led to increased accumulation of spontaneous DNA damage and cell cycle arrest characterised by reduction in ploidy of the mucinous EOC cell line EFO27. This study provides functional evidence that GWAS are powerful tools for identifying novel genes implicated with EOC and that further functional investigation of GWAS identified loci leads to a better understanding of the molecular players involved in EOC initiation, development and survival
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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