1,720,970 research outputs found
Morphological, phytochemical, and proteomic responses of Andrographis paniculata nees. to salt stress
Get PDFAndrographis paniculata Nees. is a medicinal plant belonging to the family Acanthaceae. The plant is important due to its pharmaceutical curative compound called diterpenoids. The compound is extracted from vegetative parts of the plant which was cultivated in the field from seeds. However, growing the plant is challenging especially in arid and semi-arid regions where salt concentration is relative high. In different parts of the world, the plant exists in various accessions but none of them was properly characterized for its level of salt tolerance. Therefore, the present study was conducted to determine the salt tolerance thresholds of various accessions of the plant, and finally, to characterize the accessions for their physiological, phytochemical and proteomic responses to elevated levels of salt. Salt tolerance thresholds of the various accessions of the plant were determined by exposing 6 of the accessions to different salt concentrations and exposure times at seedling. The experiments were carried out in a split split plot arrangement based on the RCBD. Based on salt tolerance threshold results various dependent parameters related to physiological, biochemical and proteomic responses of the 32 different accessions of the plant were evaluated at seedling and mature stages. Changes in metabolites and proteomes weremonitored by using HPLC and 2D-polyacrylamide gel electrophoresis, respectively. It was found that the tolerance threshold of the plant was 12 dSm-1 for 15-day of exposure time. Based on the salt tolerance index of individual accession, the plant could be grouped into salttolerant, moderately salt-tolerant and salt-sensitive accessions. When exposed to a high salt concentration, the tolerant accessions accumulated higher concentrations of proline, K+, Ca2+and andrographolide, and lower oncentration of Na+ than the sensitive ones, suggesting a salt tolerance response dictated by metabolite and ion adjustments. However, the levels ofphotosynthetic parameters were decreased in all of the accessions, which indicate that the salt stress directly reduced photosynthesis in the plant. Andrographolide content was positively correlated with salt concentration; the higher concentration of the salt the larger increase in andrographolide was observed. The concentration of three main phytochemicals (andrographolide, neoandrographolide and 14-deoxy-11, 12-didehydroandrographolide)evaluated were also positively correlated with salt tolerance index and were negatively correlated with proline content. Overall, these patterns resemble the plant’s salt tolerance responses based on physiological and phytochemical performances. At proteomic level, the tolerant accessions showed dissimilar SDS-PAGE banding patterns of soluble leaf protein of the plant exposed to high salt concentrations. These proteins were further analyzed by 2D gel electrophoresis in combination with a spot protein analysis by using the PDQuest software.The analysis led to the detection of 32 induced proteins and 12 up-regulated proteins in the leaf and root of the salt-treated plants. Of the 44 detected proteins, 12 were sequenced with three of them matched superoxide dismutase, ascorbate peroxidase and ribulose-1, 5-bisphosphate oxygenase whereas the rest were unknown. The three known proteins are generally associated with plant response to environmental stresses and could represent general stress proteins in the present study. Together, the proteomic data and the diverse physiological and phytochemical reactions demonstrated by the different accessions of the plant to salt stress would potentially be used as salt tolerance indicators in the plant’s breeding program for salt tolerance improvement
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Impact of protein diversification on morphometric behavior of Andrographis paniculata Nees
Get PDFProteins are important biochemical parameters in genetic diversity and controlling morphological characteristics in plants. In this study, the proteomic and morphometric data of an important medicinal herb “Aci Paşa” (Andrographis paniculata) were combined together to illustrate their impacts on genetic variation of the plant’s population and to realize the connection between protein patterns and phenotypic behavior of the species. We used three protein extraction buffers including Tris, potassium phosphate, and sodium citrate. The Tris buffer was significantly different (p ≤ 0.01) than other two in terms of the quality and quantity of protein bands by producing 15 types of proteins ranged from 13 to 105 kDa of which two of them were polymorphic. Consequently, a total of 12 accessions of A. paniculata were subjected to morpho-proteomic analyses. The unweighted pair group method with arithmetic average cluster analysis of the accessions based on the protein data and morphological characteristics generated three and four clusters, respectively, at a Euclidean distance of 2.53 for the morphological traits. Moreover, seed proteins analysis revealed that the two polymorphic protein bands sized 20.5 (protein “b”) and 30 kDa (protein “a”) effectively diversified the morphological characteristics and phylogenetic relationships among the 12 accessions of A. paniculata. Interestingly, the protein “b” acted as an activator agent for the number of branches, leaves and total dry weight, while the protein “a” performed a suppressive role for the same traits. Additionally, the two high-weighted faint bands “c” (75 kDa) and “d” (100 kDa) with a very low expression in accession 11228 proved their suppressive role along with the “a” band, while these bands were strongly expressed in the rest of the accessions. These findings suggest that these four proteins should be sequenced and perfectly established for further proteomic analyses. Ultimately, the mentioned proteins can be developed for any prospective breeding program or gene identification
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
