1,720,958 research outputs found
Investigating ecological drivers and impacts of vegetation change in sub Antarctic tundra
Get PDFUnderstanding the impact of environmental change on vegetation dynamics requires considering the individualistic responses of plant species, which are influenced by their specific habitat requirements and biotic interactions. For instance, habitat generalist species often have broad environmental tolerance, and may be able to adapt to and often dominate in dynamic or disturbed environments, compared to specialists that are adapted to specific environmental conditions and thus have more restricted tolerance to change. This study explores the potential for the combination of topographic, climatic, edaphic and biotic factors to influence different vascular plant species distributional and cover changes in response to the key drivers of change in the sub-Antarctic, focusing on Marion Island (MI). Given the recent origin and relative species poverty of the sub-Antarctic flora, changes in vegetation are expected to result from individual responses rather than collective trends across the entire flora or its communities. To evaluate the appropriate scale for vegetation assessment in species-poor environments, the classification of vegetation on MI was revisited. Various modern classification techniques were used to classify vascular plant species data, and the resulting classifications were compared with previous units. Due to the limited development of strong plant assemblages with discrete boundaries in the sub-Antarctic islands, community-level classification may not be suitable in such species-poor environments. Consequently, this study proposes a species-level approach aligned with continuum theory rather than community theory for more accurate vegetation monitoring in species-poor environments. Since the 1950s, MI has experienced changes in temperature, precipitation, wind conditions, and biotic interactions, with plant species thus experiencing altered environmental conditions. To investigate the vegetation cover changes across different habitats, repeat photography between 1965 and 2020 was used. Results showed an overall increase in vegetation cover in most habitats over the past five decades, accompanied by rapid drying, rising mean air temperature, changing wind direction, increased invasive plant species cover, and higher invasive house mouse abundance. Climate change and invasive species were identified as the primary interactive drivers of vegetation change. The increase in cover was primarily driven by more responsive species, such as habitat generalists, while habitat specialists either showed minimal changes or a decrease in cover. Since edaphic properties are an often overlooked component of habitat suitability or changes therein, the edaphic properties were modelled for the first time on MI to determine the spatial variation of key soil 4 properties across MI using boosted regression trees. The impact of temperature change on plant species distribution was then examined through species distribution models incorporating edaphic properties along with climatic, topographic and biotic factors. By considering a combination of climatic (changing), biotic, and non-climatic (fixed) predictors, the study aimed to determine the direction and constraints of species distributional changes under past and future temperature scenarios. Although the habitat requirements of vascular plant species on MI were species-specific, with species distributions predicted by differential variables, the responses of most generalist plant species to warming were similar, whereas responses of specialist species were similar. With continued warming, the habitat suitability of generalist plant species were predicted to increase on MI, within the physical constraints imposed by the environment, and toward the west, whereas the habitat suitability of most specialist species was not predicted to increase with warming. The results support the overarching hypothesis of this study that vegetation change on MI occurred as a consequence of the interaction of factors, key among them being climate change and invasive species. This research emphasises the individualistic responses of vascular plant species to environmental change in species-poor and/or young environments. Most habitat generalists have increased in cover and expanded their ranges, and these trends are projected to continue with warming, within the physical limitations of the environment. In contrast, the habitat suitability of specialist species show limited change, with no significant changes in cover observed or changes in range predicted with warming. Consequently, a comprehensive assessment of habitat suitability for different plant species requires considering a combination of topographic, climatic, edaphic, and biotic factors. This study highlights the importance of studying individualistic responses and understanding the specific habitat requirements of individual vascular plant species, which may be overlooked when focusing solely on species assemblage
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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