1,720,961 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
Characterisation of cucumber mosaic virus (CMV) in Catharanthus roseus (L.)G. don and its effects on anticancer metabolite production
Full text linkNatural virus-like disease symptoms such as mosaic and deformation of the leaves and flowers of malformed shape or slight colour-breaking of the petals were observed on Catharanthus roseus plants in Serdang, Selangor, Malaysia. Double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA) detected cucumber mosaic virus (CMV) in high concentrations in the leaf extract of naturally-infected C.
roseus as well as in the leaf extract of inoculated C. roseus. The purified virions were isometric particles with mean diameter 28.60 ± 0.48 nm and contained a central core. The virus induced systemic leaf mosaic on N. tabacum cv. White Burley, C. sativus, N. benthamiana and N. glutinosa. Local lesions and brown necrotic local lesions were
produced on the inoculated leaves of C. amaranticolor and V.sesquipedalis, respectively. A 1000 bp DNA fragment covering the entire coat protein (CP) region of the purified virus was amplified using the primers CMVF1(5’-TAGACAT/ACTGTGACGCGA-3’) and CMVR2 (5’-GTAAGCTGGATGGACAAC-3’). The sequence obtained (GenBank accession number EU726631) revealed a 100% nucleotide and amino acid identities to a CP gene of CMV isolated from C. roseus in India (GenBank accession number EU310928) which is a member of subgroup 1B. Cytopathological study showed that CMV infection disrupted the chloroplast ultrastructure in the C. roseus leaf cells. The presence of large starch grains in the surrounding necrotic zones caused disintegration of the stromatic lamellae and grana, changing the chloroplasts symmetry. Complex membranous structures in the cells
vacuoles and phytoferritin macromolecules in the chloroplast stroma were also observed in the leaf cells of CMV-infected C. roseus. Chloroplast was also the most altered organelle following CMV infection in the leaf cells of N. tabacum cv. White Burley, C. sativus and C.
amaranticolor. A comparative HPLC analysis on the yields of two anticancer metabolites, vincristine and vinblastine in the C. roseus leaf,stem and root tissues at different growing stages indicated that CMV infection modified the metabolism of the metabolites. Following CMV infection, the peak production period of vincristine and vinblastine in
leaves was delayed from four months old uninfected C. roseus plants to six months old CMV-infected plants. CMV infection also delayed the peak production period of vincristine in roots from five months old uninfected plants to seven months old infected ones. As for vinblastine,
the peak production period was delayed from five months old uninfected plants to eight months old infected plants. Another remarkable alteration after CMV infection is that significant increases in the contents of vincristine in the infected root tissues, particularly at six to nine
months old. The concentration of vinblastine which increased about two, four and seven-folds in the roots of six, seven and eight months old CMV-infected plants, respectively, could be another interesting finding
of CMV modification, particularly in these anticancer compounds biosynthesis pathway in C. roseus plants
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
Use of reverse transcription-polymerase chain reaction (RT-PCR) for Cymbidium mosaic virus (CyMV) detection in orchids
Full text linkThe reverse transcription-polymerase chain reaction CRT-PCR) was
adapted for detection of Cymbidium mosaic virus CCyMV) in orchids.
The oligonucleotide primers used were selected from the predicted
homologous coat protein region of CyMV and other Potexviruses
which enabled to amplify approximately 313 bp and 227 bp fragments
using optimum reaction conditions of 2.5 mM MgCh and 30 cycles of
amplification. The RT-PCR allowed the detection of CyMV RNA and virion in
purified fonns as well as in crude tissue extracts of orchid. Direct
CyMV RNA detection was possible in leaves, shoots, stems, roots and
petals. The detection limits of RNA in purified CyMV and virion by
RT-PCR described were 10 ng and 2 ng, respectively. The PCR
amplified fragments were confinned to be CyMV-specific by dotblot
hybridization with DIG-labelled CyMV cDNA probe.
The suitability of the RT-PCR in routine testing of CyMV was
detennined and compared with those of DAS-ELISA. Thirty samples
of leaf tissues representing various genera or hybrids of cultivated
local orchid from glasshouse and commercial nurseries were tested
for CyMV by RT-PCR and DAS-ELISA. Among 15 samples that
tested positive for CyMV infection by DAS-ELISA, only 7 samples
gave the expected amplification fragments when subjected in RTPCR
assays. The equal detection limit on purified CyMV virion by
RT-PCR and DAS-ELISA and lower sensitivity of RT-PCR in
detecting CyMV in a field indexing trial suggested that RT-PCR is
unsuitable to replace DAS-ELISA for routine testing of CyMV in
local orchids
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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