1,720,958 research outputs found
Dunes under attack: temporal trends of iceplant invasion (Carpobrotus sp. pl., Aizoaceae) in different landscape contexts. An insight on Mediterranean coasts
No full textCarpobrotus acinaciformis, C. edulis (Aizoaceae) and their hybrids, native to South Africa, are considered as one of the worst Invasive Alien plants (IAPs) along the Mediterranean coastal dunes causing irreversible damage in ecosystem biodiversity and loss of ecosystem services [1]. The Convention on Biological Diversity (https://www.cbd.int/) and the Regulation (EU) no. 1143/2014 on Invasive Alien Species propose a common strategy to monitor the invasion and to contrast the negative impacts of IAPs [2]. The invasion of these two species and their hybrids with similar impacts, referred here as Carpobrotus spp., is a highly dynamic process shaped by the interplay of biotic factors (e.g. competition with native communities, spread by mammals or birds), abiotic ones (e.g. coastal erosion and accumulation, seashore distance) and anthropic pressure (e.g. dune trampling, land take, artificial infrastructures) [3,4]. Due to the widespread presence of Carpobrotus spp. on Mediterranean coasts and the huge threat it poses to biodiversity, important efforts have been devoted to mapping it [5], studying its relation with biodiversity [6] and analyzing its spatial pattern in the landscape [7]. However multi-temporal studies exploring the mutual relationship between landscape dynamics and alien species expansion or contraction are still lacking.
In this context, the present work sets out to investigate landscape pattern changes occurred in areas invaded by Carpobrotus spp. (i.e. composition, configuration) during the last decade (2012-2022), and to examine the relationships among such spatial pattern changes and invaded patches dynamics.
We produced fine-scale (1:2000) land-cover/vegetation maps for two time steps (years 2012 and 2022) on invaded coastal dune in central Mediterranean (Lazio region, Italy). We mapped 95 invaded sites with a round buffer of 100 m radius by visual inspection of aerial orthophotos in Google Earth at the fourth level of CORINE land cover legend. Overall landscape change was analyzed by a transition matrix and summarized them by a chord-diagram [8]. We classified the mapped areas into two categories: EXPCAR gathering sites in which alien expansion occurs (e.g. increasing cover of Carpobrotus spp. patches in 2022) and REDCAR grouping sites with a reduction of alien cover over time (e.g. decreasing cover of Carpobrotus spp. patches in 2022). For each area and time step, we calculated a set of non-redundant landscape metrics (LM) depicting the spatial pattern of the whole coastal mosaic (LMland) and of each land cover class (LMclass). In particular: the percentage of the landscape covered by each class (PLAND), patch density (PD), edge density (ED), mean patch area (AREA_MN), Shannon index (SHDI) and Simpson’s index (SIDI) [9] and we tested their temporal difference through non-parametric pair-wise Wilcoxon rank test. Then, we quantified changes in pattern metrics occurring in each cover category by computing ΔLM = 2022LM - 2012LM and we explored the partial dependence of the changes on Carpobrotus spp. spatial pattern (ΔLMCAR) in the coastal dune landscape variables without multicollinearity problem and Variance Inflation Factor (VIF) lesser of three (ΔLMclass, ΔLMland) using a Random Forest model (RF) and Partial Dependence Plot (PDP) [10]. In general, the transition matrix confirms natural dynamism of coastal dune during the last 10-years with comparable shifts towards adjacent land cover classes. Landscape analysis over time evidenced important changes on Carpobrotus spp. spatial pattern during the last decade (2012-2022) and such changes varied across coastal dune tracts in which invasion is expanding (EXPCAR) or contracting (REDCAR). In EXPCAR areas a quite stable coastal context was evidenced, while in REDCAR intense erosion process was detected. Focusing on Carpobrotus spp., in EXPCAR areas, the chord diagram evidenced an increment of CAR class extension substituting HDV class, and on REDCAR areas CAR class decreased and was replaced mainly by SEA and partially recovery by HDV. Consequently, the spatial pattern of Carpobrotus spp. patches significantly changed over time with opposite trends, all landscape metrics intensify in EXPCAR areas causing increase in pressure and impacts on HDV, while in REDCAR areas all landscape metrics show a contraction and simplification of invasion due to very high fragmentation caused by erosion process. Moreover, all RF models and PDP, adequately described the relation of temporal changes in Carpobrotus spp. composition (ΔPLANDCAR) and configuration (ΔPDCAR, ΔEDCAR, ΔAREA_MNCAR) with changes on the spatial pattern of the surrounding landscape (ΔLMclass and ΔLMland) with R2 values greater than 0.405.
The different trends of Carpobrotus spp. expansion or reduction denote the heterogeneous contribution of class and landscape dynamics in determining its spread. Here for the first time, we quantify the multi-temporal effects of landscape pattern and processes to shape Carpobrotus spp. invasion discerning different trends in increase and contraction of invasion [11]. These information concerning IAP occurrence needs to be supported by the knowledge on landscape processes to identify effective conservation and management strategies as claimed by international and regional regulations on biodiversity
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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