1,720,953 research outputs found
Water holes typology as a function of human and ungulate Activities in Hwange National Park, Zimbabwe
No full textSmall aquatic ecosystems in semi-arid environments are characterised by strong seasonal water level fluctuations. Artificial pumping of ground water to maintain water resources throughout the dry season may affect the limnochemical characteristics of the aquatic ecosystems. The limnology of water pans (pumped and unpumped) in Hwange National Park (Zimbabwe) was studied by determining the seasonal, spatial variation of selected physico-chemical parameters, investigating environmental variables affecting plankton communities in the study sites and assessing of organic matter inputs from terrestrial herbivores. Nineteen temporary and permanent water pans were sampled for seven months in 2013 across the wet (February, March, April, and December) and dry seasons (July, September and November) and analysed for standard physicochemical parameters. Results showed an increase in conductivity, hardness, magnesium and calcium when temporary pans dry up, and when permanent ones are filled with ground water. The concentrations of ions and hardness of water was higher in pumped pans due to groundwater. Higher turbidity was observed during the rainfall season in natural pans, while in artificial pans it occurred during the dry season. The water in all pans showed alkaline conditions. The pumped pans also recorded the highest concentrations of nutrients (total nitrogen and ammonia) during the dry season. In particular, in times of water scarcity, animals gather around artificially maintained waterholes and foul water with faeces and urine, thus inducing water eutrophication. Seasonal variation in conductivity, hardness, turbidity, calcium, magnesium and turbidity suggests the influence of water level fluctuations associated with rainfall, evaporation and pumping activities. Seasonal and spatial distribution of plankton communities and the effect of environmental variables on plankton community composition were investigated in the same temporal, natural and permanent, artificial pans for the same period. In total, forty-three phytoplankton species belonging to thirty-seven genera and fifty-six zooplankton species belonging to twenty-three genera were recorded. Species richness and diversity decreased in both phytoplankton and zooplankton communities during the dry season, although this was more pronounced for zooplankton. During both the dry and wet months, diatoms and rotifers dominated the phytoplankton and zooplankton communities, respectively, in both permanent and temporal pans. Canonical correspondence analyses showed salinity, vegetation, calcium, nutrients, dissolved oxygen and turbidity as the different environmental factors that influenced the plankton community structure in both natural and artificial water pans. An assessment of direct nutrient inputs of terrestrial wildlife into the studied shallow water bodies was also carried out for six months in 2014. Dung from different herbivore species was collected during the dry (June, August and October) and wet (February, March and May) seasons to measure nutrient content and estimate nitrogen and phosphorus leaching rates. Results obtained showed changes in dung nutrient composition between the seasons. The deposition during the dry season of total carbon, nitrogen, and phosphorus, mostly due to elephants, was estimated to be 8.65, 0.25, and 0.06 g/m²/day, respectively, while the leaching rates of dissolved inorganic nitrogen and phosphorus were 0.11 mg and 0.17 mg m²/day, respectively. Water bodies which do not dry up during the dry season attracted wild animals, which caused significant nutrient enrichment. During the wet season there were strong surface water inflows which coincided with reduction of nutrients, conductivity and water hardness levels leading to increased aquatic production (zooplankton and phytoplankton biomass).During the dry season there was contraction of the studied freshwater ecosystems coupled with loss of flow, reduction of clarity due to increase of nutrients from allochtonous organic matter and establishment of cyanobacterial blooms. Due to the small size of the studied waterholes conditions deteriorate within the ecosystems during the dry season with noticeable change in plankton assemblages. The wet season flushing resets the system. In conclusion spatial and temporal variation was observed between the study sites (natural and artificial water pans) with characteristics of both types of pans being influenced by organic matter from terrestrial herbivores
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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