1,720,954 research outputs found
Seasonal Variation in Arsenic Concentration and its Bioremediation Potential of Marine Bacteria Isolated from Alang-Sosiya Ship-Scrapping Yard, Gujarat, India
Get PDFThis work investigates seasonal variations in arsenic concentration at Alang-Sosiya, world’s largest ship-scrapping yard situated on the Gulf of Khambhat. Annually, hundreds of ships have been dismantled, which lead to discharge large amounts of detrimental and persistent pollutants at this location. In all seasons, the arsenic concentration was significantly elevated in sediments and seawaters in the intertidal zone of Alang-Sosiya ship-scrapping yard as compared to the reference station at Ghogha, 42 km away towards the northeast. The highest arsenic concentrations in seawater and sediment samples were observed during the Winter season and Summer season respectively. The marine environment affected by ship-scrapping activity and contaminated with arsenic is the potential location to get arsenic hyper-tolerant bacterial isolates. Out of 16 isolated bacterial strains, KKDK-1 and KKDK-2 sustained 600 mM and 500 mM arsenate respectively. The 16S rRNA ribotyping identified strains KKDK-1 and KKDK-2 as Halomonas species. The strain KKDK-1 showed the maximum arsenic accumulation of 21.7±3.3 mg g-1 cell dry weight at exponential phase (60 h), followed by sudden extrusion of arsenic during stationary phase (84 h) of bacterial growth. Whereas, strain KKDK-2 accumulated 6.8±1.12 mg Arsenic g-1 cell dry weight during exponential phase (72 h), which remains almost invariable during stationary phase (96-144 h) of bacterial growth. These results indicate the hypertolerance of arsenic by KKDK-1 and KKDK-2 with its higher accumulation capacity, signifying them as potential candidates for arsenic detoxification of arsenic contaminated sites
Isolation and Characterisation of Urease Producing Bacteria and their Capacity to Precipitate Calcium Carbonate
Get PDFThe current study was designed to isolate and characterize urease-producing bacteria and to assess their ability to precipitate calcium carbonate. Total eight bacteria were isolated from dung-rich soil samples collected from Dakor, Gujarat. Out of these, two bacterial strains designated as DGDK-3 and DGDK-4 were found to produce a considerable level of urease in the initial screening on the urea agar medium. Based on morphological and physiological tests and more specifically by 16S rRNA gene sequencing analysis, these bacteria were identified as Quasibacillus sp. Strain DGDK-3 and Bacillus sp. Strain DGDK-4. The strains DGDK-3 and DGDK-4 showed 25 IU/ml and 89 IU/ml urease activity, respectively. Also, the efficacy of both strains was tested for calcium carbonate precipitation. Results showed that both the isolates were competent to precipitate a significant level of calcium carbonate. The current work demonstrated that urease-producing bacteria can be utilised in bio-cementationas a crack sealing agent and as a natural stabilizing agent
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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