1,720,954 research outputs found
The classification and mapping of Lapalala Wilderness Reserve, Limpopo
Get PDFDissertation (MSc (Plant Science))--University of Pretoria, 2021.Vegetation classifications and maps form the foundation of understanding spatial variation in vegetation and the environmental conditions driving the occurrence of plant assemblages and form a baseline for detecting changes in vegetation. They are considered an important tool for land-use planning and conservation of natural ecosystems, allowing managers to make informed decisions. The aim of this dissertation was to (1) create a vegetation classification for Lapalala Wilderness Nature Reserve, distinguishing major plant communities and correlated environmental factors, and (2) map the distribution of these plant communities across the study area.
Lapalala Wilderness Nature Reserve spans 48 000 ha and is part of the Waterberg Bioregion in Limpopo, South Africa. The reserve plays an important part in conservation of both flora and fauna, and to support management and develop conservation strategies, the need for an updated vegetation map was recognised. One hundred and eighty 20 x 20 m relevés (comprised of 355 species) were sampled in January-March 2019 for this study. Canopy cover was estimated for all vascular plant species and environmental variables collected in the field include bare ground, rock cover, geographic location and elevation. Slope, aspect, curvature, topographic wetness index, topographic position index, distance to water, number of years since the last fire, and the number of fires in the last 10 years were determined for each relevé. Soil samples were analysed for phosphorus, sodium, calcium, potassium, magnesium, organic carbon and pH, and their particle size distribution was determined.
The OptimClass method identified that the best data-analytical combination for this dataset was Relativized Manhattan dissimilarity index and group average clustering with 10 clusters and no data transformations.The identified communities were Community 1: Combretum molle-Schmidtia pappophoroides woodland, Community 2: Senegalia nigrescens-Heteropogon contortus woodland, Community 3: Terminalia sericea-Aristida diffusa woodland, Community 4: Burkea africana-Eragrostis gummiflua woodland, Community 5: Cynodon dactylon-Eragrostis patentipilosa grassland, Community 6: Grewia monticola-Vachellia nilotica woodland, Community 7: Euclea linearis shrubland, Community 8: Cymbopogon pospischilii grassland, Community 9: Vitex obovata-Phyllanthus parvulus shrubland, Community 10: Andropogon eucomus-Eragrostis heteromera grassland. Out of the 37 environmentals variables, 21 had a significant effect on the composition of communities, with many of these variables being related to soil texture (n = 10) and soil nutrient content (n = 7).
CART was used to map the communities. However, mapping the study area was not very accurate due to weak relationships between satellite-derived variables and the occurrence of the communities, but estimates a heterogeneous mosaic of communities. Two communities were widely distributed across the study area, Community 1, comprising 66% of the mapped area, and Community 2 (26%), with small patches of Community 3 (3 %) and Community 5 (5 %). An accuracy assessment of the map showed an overall accuracy of 70 % and kappa index of 40%.
In summary, there was no strong differentiation between the communities in terms of species composition or environmental variables, and, as a result, the plant communities do not represent clear management units. Due to a paucity of vegetation studies and landscape-scale vegetation maps in the Waterberg, this study provides an important step in developing a deeper understanding of the vegetation in this ecologically-important region.Mapula Trust, Lapalala Wilderness Nature ReservePlant ScienceMSc (Plant Science)Unrestricte
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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