1,720,958 research outputs found

    Effects of extremely low frequency electromagnetic field on physical and biochemical characteristics of selected tissue cultured plants

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    The extremely low frequency electromagnetic field (ELF-EMF) occurs naturally from the Earth and artificially from human inventions. The electric power lines which lie across many plantations in Malaysia is one of the examples of the source of ELF-EMF. Earlier research demonstrated that some plants exposed to ELF-EMF respond positively in terms of growth and biochemical properties. Therefore, it was hypothesized that ELF-EMF is able to stimulate plant’s growth. The objectives of this study were to develop a suitable ELF-EMF generator, to determine the effects of ELFEMF on plant development, and to analyze the biochemical changes occurs in plants exposed to ELF-EMF. Initially, an ELF-EMF generator, the coGEM 1000 was constructed using four coils of copper wires that were connected to a transformer, a multimeter, and a rheostat. The coGEM 1000 suitable for tissue culture plants is able to produce stable and uniform 6 and 12 mT 50 Hz ELF-EMF in the four coils of the ELF-EMF generator. Four different species of tissue culture plants, namely tobacco plant, banana, orchid, and ficus were exposed to ELF-EMF. All these in vitro plantlets were incubated in a controlled environment prior to exposure to 6 and 12 mT of 50 Hz ELF-EMF for a period of 0.5, 1, 2, and 4 hours. The parameters observed were the number of shoots, shoot height, and number of leaves (growth characteristics) and biochemical properties, such as chlorophyll a and b content, total chlorophyll content, ratio chlorophyll a/b, carotene content, and activities of the enzymes namely catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD), and glutathione reductase (GR). For tobacco plant, the exposure to 6 mT ELF-EMF for an hour had increased the shoot height (3 cm),chlorophyll a (32.8 mg/g) and SOD activity (1.9 U/mg protein); whereas,the exposure to 6 mT ELF-EMF for 0.5 hour had increased the number of shoots (1.4) and total soluble proteins (23.3 mg/g) of the banana plant. However for orchid plants, higher ELF-EMF the exposure to (12 mT) for longer duration (4 hours) had induced a high number of shoots (3.5),number of leaves (10.2) and CAT enzyme activity (1.0 U/mg protein). In contrast to the former, ficus plant exposed to extended periode of ELFEMF did not induce any changes in the growth characteristics. However;the exposure of ficus plant to 12 mT ELF-EMF for 4 hours showed an increased in the activity of CAT (9.8 U/mg protein) and APX (13.2 U/mg protein). It is concluded that different plant species requires different strength and duration of exposure to ELF-EMF to promote growth and development. In addition, the exposures of the selected plant species to the ELF-EMF were able to promote the plant abilities to resist the presence of reactive oxygen species (ROS) generated in tissue culture. These have been illustrated by the increase of the various antioxidative enzymes activities (SOD, CAT and APX) presence in the selected plants species (viz. tobacco, orchid, and ficus plant, respectively). These results suggest that the application of ELF-EMF may help to promote in vitro plant growth through creating a plant that can resist the ROS. This findings provide a foundation for further apllication of the ELF-EMF in promoting plant growth

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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 Under Sail The Imagination of Jack London, 1893-1902

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    In Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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