1,720,956 research outputs found
Cloning and characterization of three homoeologous wheat PDI-like genes located on group 5 chromosomes
No full textPDI and PDI-like proteins are responsible for multiple metabolic functions, including secretory protein folding, chaperone activity and redox signalling. In plants the proteins of the PDI family cluster into eight phylogenetic classes, five of them include proteins with two thioredoxin (TRX)-like active domains, whereas the other three classes own a single TRX-like domain. The first class includes the typical PDI, which in cereals may be involved in the folding of secretory proteins during the formation of endosperm protein bodies. The three homoeologous genes coding for the typical PDI and their promoter sequences had previously been isolated and characterized. Their exon/intron structure is highly conserved and includes 10 exons. Recently we reported the characterization of the whole set of nine non-homoeologous PDI-like gene sequences of wheat; since phylogenetic analysis assigned them to the eight plant subfamilies, at least one wheat gene has been cloned for each group. In this study we report the characterisation of the genomic and cDNA sequences of three homoeologous PDI-like genes (TaPDIL5-1A, TaPDIL5-1B and TaPDIL5-1D) of the V phylogenetic group and located in chromosome arms 5AL, 5BL and 5DL of hexaploid wheat. The coding region and the exon/intron structure, consisting of nine exons, of their genomic sequences were highly conserved. The most relevant differences were detected in the length of the second (1393 bp in TaPDIL5-1B, 1076bp in TaPDIL5-1A and 1026 bp in TaPDIL5-1D) and fifth (967 bp in TaPDIL5-1D, 723 bp in both TaPDIL5-1A and TaPDIL5-1B) introns. Their ORFs consisted of 1323 bp, corresponding to polypeptides of 440 aa, with an estimated Mw of 47.2 KDa and pI of 5.3. The three encoded proteins possessed two tandem TRX active domains (a°-a), each containing the typical tetra-peptide site -CGHC-, an inactive TRX b domain at its C-terminus, the signal peptide and a modified NDEL signal for retention in the ER. The comparison of the wheat sequences with the PDI-like genes of the V phylogenetic group from Ararabidopsis, rice and the moss Physcomitrella patens revealed a high level of conservation of their structural features, in terms of intron pattern and exon number, size and position of the active sites. The promoter sequence of the PDI-like gene located in 5A chromosome of bread wheat cv Chinese Spring was cloned using the inverse PCR (IPCR) tecnique. The sequence analysis showed that the fragment cloned by IPCR included about 1400 bp located upstream of the coding sequence. The promoter sequences of the PDI-like genes located in 5B and 5D chromosomes of C. Spring were cloned through PCR amplification using two primer pairs. One of the primers, the same for both pairs, was designed on the basis of a sequence in the distal region of the previously cloned promoter of the 5A chromosome, whereas the second specific primer of each pair was chosen within regions of the
second intron. The search of cis-acting regulatory elements within the promoters of the three genes was performed using the databases of plant promoters PlantCARE and PLACE and the differences between the three sequences will be discussed. Finally, transgenic durum wheat lines (cv Svevo) over-expressing the gene located in 5A chromosome, which was put under the control of the ubiquitin promoter of maize, were produced for the functional characterization of this gene. PCR analyses of 40 plants regenerated from 800 bombarded embryos showed that 5 of them were transgenic for the PDI over-expression construct
Fluctuations in Fe availability are translated into modulation of plant sulfate metabolism at both transcriptional and physiological level in durum wheat
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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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