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Physical mechanisms of nutrient supply and controlling factors of phytoplankton growth in the Arafura Sea
No full textThe Arafura Sea is a relatively shallow basin (< 200 m deep) located in the eastern part of the Indonesian archipelago. Its border on the west is a deeper basin, the Banda Sea, with an average depth of ∼5000 m. Previous studies have shown that circulation in this particular region is mainly influenced by monsoonal winds, which are the northwest (NW) and southeast (SE) monsoons. In addition, previous studies have shown that upwelling is a characteristic phenomenon in this region, induced by the SE monsoon from June to August. During this period, the lower sea surface temperature and elevated chlorophyll-a concentrations are observed near the coast of Papua (northern Arafura Sea). Recent studies have suggested that these features are due to the upwelling of cold and nutrient-rich water masses originating from deeper layers of the Banda Sea.
The present study aims to investigate the mechanism of nutrient supply and its implication on phytoplankton distribution in further detail using a numerical model. A three-dimensional (3D) biogeochemical model ECOHAM (ECOsystem model HAMburg) is utilized in this study. The model domain extends from 122°–139°20’ E and 1°48’–14°19’ S, covering the Arafura and the Banda Sea regions. ECOHAM is forced by ocean current fields derived from HAMSOM (HAMburg Shelf Ocean Model), river run-off, atmospheric nitrogen deposition, wind stress, and solar radiation. Moreover, the initial and boundary values of biogeochemical variables are derived from WOA and GCOMS. Finally, the model results are validated against the in-situ nutrient measurements and satellite-derived chlorophyll-a concentration.
The simulated nutrient (i.e., nitrate and phosphate) concentrations show a good fit with observations, especially in the upper 200 m. Besides nutrients, the simulation overestimates surface chlorophyll-a concentrations in the northern Arafura Sea, but it still represents the seasonal variation quite well. Furthermore, the sensitivity test reveals that a 10% change in temperature factor Q10 for phytoplankton can significantly changes the Redfield net primary production by up to 25%.
This modeling study suggests a different mechanism of nutrient supply between the shallow region in the northern part (Sahul Shelf) and the continental slope area of the Arafura Sea. In the Sahul Shelf, nitrate is primarily transported to the near-surface layer via vertical mixing, which is stronger during the SE monsoon, compared to the NW monsoon. On the other hand, nitrate supply in the continental slope area is mainly regulated by advection. During the NW monsoon, the simulation reveals the horizontal intrusion of nitrate-rich water masses from the eastern Banda Sea in the layer above the nitracline (a layer in which the nitrate concentration increases rapidly with increasing depth). By contrast, during the SE monsoon, the vertical advection transports nitrate to the layer above the nitracline, which is confirmed by nitrate budget analysis.
Furthermore, this study shows that phytoplankton growth is mainly regulated by nitrogen availability. In the Sahul Shelf, the seasonal variations of phytoplankton production and zooplankton grazing indicate the bottom-up control in June-August and top-down control in October-December in the zooplankton-phytoplankton system. In the continental slope area, nitrate concentration in the near-surface layer is depleted, suggesting a strong nitrate limitation, especially for diatoms. In this region, non-diatom production is higher than for diatom because non-diatoms take up ammonium more effectively
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn 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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