1,720,965 research outputs found
Dissecting a QTL into Candidate Genes Highlighted the Key Role of Pectinesterases in Regulating the Ascorbic Acid Content in Tomato Fruit
Tomato (Solanum lycopersicum) is a crucial component of the hu- man diet because of its high nutritional value and the antioxidant content of its fruit. As a member of the Solanaceae family, it is considered a model species for genomic studies in this family, especially since its genome has been completely sequenced. Among genomic resources available, Solanum pennellii introgres- sion lines represent a valuable tool to mine the genetic diversity present in wild species. One introgression line, IL12-4, was previously selected for high ascorbic acid (AsA) content, and a transcriptomic analysis indicated the involvement of genes control- ling pectin degradation in AsA accumulation. In this study the integration of data from different “omics” platforms has been ex- ploited to identify candidate genes that increase AsA belonging to the wild region 12-4. Thirty-two genes potentially involved in pathways controlling AsA levels were analyzed with bioinformatic tools. Two hundred-fifty nonsynonymous polymorphisms were detected in their coding regions, and 11.6% revealed deleterious effects on predicted protein function. To reduce the number of genes that had to be functionally validated, introgression sublines of the region 12–4 were selected using species-specific polymor- phic markers between the two Solanum species. Four sublines were obtained and we demonstrated that a subregion of around 1 Mbp includes 12 candidate genes potentially involved in AsA accumulation. Among these, only five exhibited structural delete- rious variants, and one of the 12 was differentially expressed between the two Solanum species. We have highlighted the role of three polymorphic pectinesterases and inhibitors of pectinester- ases that merit further investigation
Exploiting the great potential of Sequence Capture data by a new tool, SUPER-CAP
The recent development of Sequence Capture methodology represents a powerful strategy for enhancing data generation to assess genetic variation of targeted genomic regions. Here, we present SUPER-CAP, a bioinformatics web tool aimed at handling Sequence Capture data, fine calculating the allele frequency of variations and building genotype-specific sequence of captured genes. The dataset used to develop this in silico strategy consists of 378 loci and related regulative regions in a collection of 44 tomato landraces. About 14,000 high-quality variants were identified. The high depth (>40×) of coverage and adopting the correct filtering criteria allowed identification of about 4,000 rare variants and 10 genes with a different copy number variation. We also show that the tool is capable to reconstruct genotype-specific sequences for each genotype by using the detected variants. This allows evaluating the combined effect of multiple variants in the same protein. The architecture and functionality of SUPER-CAP makes the software appropriate for a broad set of analyses including SNP discovery and mining. Its functionality, together with the capability to process large data sets and efficient detection of sequence variation, makes SUPER-CAP a valuable bioinformatics tool for genomics and breeding purposes
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
QTL pyramiding and selection of introgression sub-lines represent efficient tools to improve nutritional quality in tomato fruit.
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