1,720,998 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
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
Evaluation of the nephrotoxic effects of insecticide diazinon in rats
Full text linkOxidative damage of biomolecules is implicated in the pathogenesis of various renal inJuries. Diazinon (O,O-diethyl-O-[2-isopropyl-6-methyl-4-pyrimidinyl] phosphorothioate), an organophosphate insecticide, has been used worldwide in agriculture and domestically for several years, which has led to a variety of negative effects in non target species including humans and therefore, are cause of concern. There are few studies on diazinon with reference to its toxicity in kidney on exposure to low doses based on LD50. The possible toxicity of diazinon is assumed to be as a result of induction of oxidative stress, however, there are not enough studies to confirm this as a result of exposure to low doses of diazinon for acute, subacute and chronic periods. Therefore, the present study was conducted to analyze the direct toxic effects of diazinon which caused biochemical and ultrastructural changes and to evaluate its mechanism of action with special reference to its possible reactive oxygen species generating potential (ROS) in kidney with acute, subacute and chronic exposure in rat models. Adult Sprague Dawley male rats were treated with diazinon in corn oil orally (gavage) according to the selected doses (10 mg/kg body weight, 15 mg/kg body weight and 30 mg/kg body weight) for 7, 14 and 56 consecutive days. The selection of dose regimen of diazinon was based on previously published data which indicate substantial alterations in many biochemical parameters. All of these animals were sacrificed 24 h after the last dose of diazinon or saline within a period of 1 h. Blood and kidney tissues of these animals were taken quickly. Kidneys were cleaned free of extraneous material and perfused immediately with ice cold saline (0.85% w/v, sodium chloride) for biochemical and histopathological studies to assess the derangement in the functioning of kidney. Body weight decreased Significantly in diazinon treated group compared to the saline treated control. Treatment of rats with diazinon induces oxidative stress in kidney, as evident by significant induction in lipid peroxidation (TBARS) which is accompanied by depletion of enzymatic and non-enzymatic antioxidant molecules (viz. GPx-glutathione peroxidase; GR-glutathione reductase; GST glutathione S-transferase; G6PD-glucose 6-phosphate dehydrogenase; CAT-catalase; GSH-reduced glutathione). In contrast, activities of renal y-glutamyl transpeptidase (yGGT) and quinone reductase (QR) were increased significantly. Parallel to these changes, diazinon treatment enhances renal damage as evidenced by sharp increase in blood urea nitrogen (BUN) and serum creatinine (CRN). Additionally, histopathological examinations showed extensive renal injuries, characterized by nuclear pycnosis, kidney swelling with obliteration of space in Bowman's capsule, degeneration of tubular epithelial cells, necrosis of proximal tubules, flattened epithelium and congested blood vessels. Reviewing all observations, our results indicate that diazinon treatment eventuates in decreased renal glutathione, a fall in the activities of antioxidant enzymes including the enzymes involved in glutathione metabolism and excessive production of oxidants with concomitant renal damage, all of which are involved in the cascade of events leading to diazinon-mediated renal oxidative stress and toxicity. We concluded that in diazinon exposure, depletion of antioxidant enzymes is accompanied by induction of oxidative stress that might be beneficial in monitoring diazinon toxicity
Phytochemical constituents, antioxidant and chemopreventive effects of selected plants against carbon tetrachloride (CCL4)-Induced hepatic damage in rats
Full text linkCommelina nudiflora, Nephrolepis biserrata and Dillenia suffruticosa have been used in folk medicine for protection against different diseases such as jaundice, although their actual efficiency remains uncertain. The current experiment was designed to investigate the bioactive compounds and hepatoprotective potential of the selected plants against carbon tetrachloride (CCI₄)-induced hepatic oxidative damage in rats and their possible mechanism of action. The total phenolic and flavonoid contents, phytochemical constituents and antioxidant activates were determined in the methanolic extracts and methanolic fractions of plant samples. Phytochemical analysis was performed by gas chromatography and mass spectrometry (GCMS). In this in vivo study, Sprague Dawley rats were pre-treated with various doses of the methanolic extracts of the selected plants once daily for 14 days followed by two doses of CCI₄ (1ml/kg b. wt. ). After 24 hours of the last dosage, the rats were sacrificed and hepatoprotective analyses were performed on the rat's liver. The obtained data revealed that the methanolic extracts and methanolic fractions of C. nudiflora, N. biserrata and D. suffruticosa possessed strong antioxidant activities and have the ability to scavenge DPPH free radicals effectively. The GCMS analysis of the methanolic extracts and methanolic fractions of C. nudiflora, N biserrata and D. suffruticosa demonstrated the presences of different bioactive compounds of various natures. The identified bioactive compounds have been reported with antioxidant, anti-inflammatory and hepatoprotective properties. The animal studies indicated that the methanolic extracts of C. nudiflora, N biserrata and D. suffruticosa showed hepatoprotective effects against CCI₄- induced hepatic damage. The administration of Methanolic extracts of the plants depleted the elevation of enzymatic levels of serum transaminases, reduced the extent of malondialdehyde production, elevated the level of reduced glutathione and also increased the activities of antioxidant enzymes. The histopathological examination by light and electron microscopy indicated that these plant extracts protect the liver from the toxic effects of CCI₄ and healed lesions such as necrosis, fatty degeneration and hepatocyte injuries such as irregular lamellar organization and dilations in endoplasmic reticulum. The immunohistochemical studies revealed that the administration of plant extracts decreased the formation of 4- hydroxyl-2-nonenal (HNE) modified protein adducts and 8-hydroxy- 2- deoxygunosine (8-OHdG) as compared to the CCI4-intoxicated group. Furthermore, the overexpression of the pro-inflammatory markers TNF-a, IL-6 and PGE2 are also reduced. Collectively, these plants alleviated CCI₄- induced hepatic damage via modulation of hepatic metabolizing enzymes, suppression of oxidative stress, inhibition of inflammatory cytokines and PGE2 in liver. These findings exhibit the potential prospects of C. nudiflora, N biserrata and D. suffruticosa as functional ingredients to prevent ROS-related liver damage
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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