1,720,963 research outputs found
The ecology of phytoplankton with focus on cyanobacteria and of aquatic macrophytes in selected lakes and reservoirs in Myanmar
Get PDFMyanmar’s freshwater systems are increasingly subjected to degradation, eutrophication, and anthropogenic impacts. The most visible effects of eutrophication in lakes and rivers are dense blooms of noxious, foul-smelling phytoplankton (mainly cyanobacteria), increased organic loading and sedimentation, fish mortalities, reduction of water clarity and degraded water quality and quantity. Many cyanobacterial species are known to produce toxic compounds, cyanotoxins, which can affect terrestrial and aquatic organisms. The control of cyanobacteria, therefore, is vital for freshwater resource management. Many studies have pointed out that aquatic macrophytes can suppress the structure and variation of phytoplankton communities and enhance water clarity by competing for nutrients, releasing allelopathic compounds and shifting environmental light levels. However, no detailed study on the presence of cyanobacteria and their potential toxin production has been conducted so far in Myanmar’s water bodies. There is also limited or no information on the influence of macrophytes on the function of freshwater systems. More broadly, the interaction between macrophytes and phytoplankton is poorly understood in Myanmar’s freshwater lakes. The overall goal of this study is therefore to improve knowledge about the composition and abundance of phytoplankton and macrophytes, and their interaction in Myanmar's freshwater systems.
The presence of toxin-producing cyanobacteria and cyanotoxins were investigated at Meiktila Lake and Yezin Dam, while an assessment of the importance of aquatic macrophytes as a stabilizing factor in a tropical shallow lake was conducted at Inlay Lake. The distribution of Chara spp. and their ecological requirements was investigated in six water bodies: two natural lakes and four man-made reservoirs. Water sampling and field surveys were conducted in each lake and reservoir 2 to 8 times from 2014 to 2019.
Compared to Inlay Lake, higher phytoplankton biomasses were found in Meiktila Lake and Yezin Dam, of which cyanobacteria were the most dominant groups. Among cyanobacteria species, Raphidiopsis raciborskii was the most dominant taxa (0.2 – 1.9 mg L-1) in Meiktila Lake, while lower biomass (0.0002 - 0.2 mg L-1) was recorded in Yezin Dam. Dolichospermum smithii was only found in Yezin Dam with the highest biomass of 19.18 mg L-1. Neither of these species were observed in Inlay Lake. Low concentrations of Microcystis were found in all the lakes and reservoirs studied in Myanmar. Microcystis has been reported from only a few water bodies in Myanmar before, but is described from many Asian countries.
This study clearly demonstrates the presence of CYN- and deoxy-CYN producing R. raciborskii and MC-producing Microcystis in the cyanobacteria communities of the investigated lakes and reservoirs in Myanmar, confirmed by Enzyme-linked immunosorbent assay (ELISA) and liquid chromatography with tandem mass spectrometry (LC-MS/MS) (LC-HRMS/MS). Although Dolichospermum smithii was the most dominant species in Yezin Dam, none of the Dolichospermum strains isolated appear to produce any toxins, unlike strains from other locations worldwide.
Although 22 Microcystin (MC) congeners were produced by the Microcystis strain (AB2017/08) of Yezin Dam, MC-LR and [D-Asp3] MC-LR were the dominant MC congeners, comprising 76.9 % and 15.7 % of the total MCs detected. Microcystis strain (AB2017/14) from Meiktila Lake with 52 MC congeners produced a considerably higher number of MCs, but MC-LR and [D-Asp3] MC-LR together made up only 20 % of the total MC concentrations. Due to the presence of CYN-and MC-producing cyanobacteria in these lakes and dams, harmful effects on humans, domestic and wild animals cannot be excluded.
This study also fills the knowledge gap on the current distributions of Chara species in lakes and reservoirs in Myanmar. Two Chara species, Chara zeylanica and C. fibrosa, were recorded in our lake survey in 2014 – 2019. Both species were recorded in low-impacted lakes only, with total phosphorous (TP) concentrations below 20 μg L−1. Increased human impact on freshwater habitats must therefore be considered as a factor reducing Chara biodiversity in Myanmar.
Regression analysis showed that the submerged macrophyte abundance and phytoplankton biomass were inversely correlated in the heavily vegetated northern lake area. Our survey suggests a great importance of the submerged macrophytes to the general water quality and the clear water state in Inlay Lake. Maintaining high macrophyte abundances should thereforepublishedVersio
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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