1,720,968 research outputs found
Exogenous aminolevulinic acid protects wheat seedlings against boron-induced oxidative stress
No full textThe present study was carried out in order to elucidate whether exogenous ALA treatment mitigates the stress damages in wheat under boron toxicity. Three different concentrations (5, 10 and 20 mg.L-1) of ALA were applied to the 9-day-wheat leaves and then boron (5 mM) was added to the nutrient solutions for 3 days. Boron toxicity severely reduced root and shoot lengths as well as the level of soluble protein and photosynthetic pigments. In a similar manner, it caused a markable decrease in the activities of antioxidant enzymes including superoxide dismutase, guaicol peroxidase, catalase, ascorbate peroxidase and glutathione reductase. As a result, boron toxicity led to increment in the level of oxidative stress indicators such as superoxide anion, hydrogen peroxide, and lipid peroxidation. ALA application significantly mitigated the boron-induced reductions in the growth parameters and antioxidant defence system. The values of oxidative stress indicators were lesser in ALA-applied seedlings that were associated with higher activities of antioxidant enzymes as well as higher protein level. A significant correlation was recorded between boron and/or ALA-induced protein content and protein profile observed at SDS-PAGE. On the other hand, while boron application caused to a marked increase in boron amounts in roots, ALA treatments reduced considerably the boron uptake from roots. These data clearly revealed that ALA improves boron toxicity in wheat seedlings by increasing antioxidant activity and by modulating boron uptake and/or transportation
Exogenous progesterone application protects chickpea seedlings against chilling-induced oxidative stress
No full textThis experiment was conducted to monitor the influence of foliar progesterone application on the chilling tolerance of chickpea seedlings. Twelve-day-old chickpea seedlings were treated with 10(-7) mol L-1 progesterone. After 12 h, the seedlings were exposed to day/night temperatures of 9/5 A degrees C for 72 h in a growth chamber. Chilling stress resulted in remarkable increase in the activities of antioxidant enzymes including superoxide dismutase (SOD), guaicol peroxidase (POX), catalase, ascorbate peroxidase (APX) and glutathione reductase, as well as the level of antioxidant compounds like ascorbic acid, glutathione and proline. In a similar manner, chilling stress affected significantly oxidative stress indicators measured as superoxide production, electrolyte leakage, hydrogen peroxide (H2O2) and malondialdehyde contents. The values of these parameters were lesser in progesterone-applied seedlings that were associated with higher activities of antioxidant enzymes and greater levels of antioxidant compounds in these seedlings. A highly significant correlation was recorded between SOD, POX and APX activities and their isozymes. This correlation confirmed enhanced activities of these enzymes. In addition, progesterone application ameliorated chilling-induced decrease in relative leaf water content (RLWC) and chlorophyll content. Freezing tolerance, showed by thermal analysis method, proved that progesterone application improved chilling tolerance of chickpea seedlings by lowering freezing point from -4 to -5.5 A degrees C. It is possible that chilling tolerance induced by progesterone is related to elevation of RLWC, chlorophyll content and antioxidative activity, and thereby decrease in oxidative stress indicators
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
- …
