1,720,958 research outputs found
Microplastics in the marine environment: new frontiers of investigation of their presence and related associated effects
No full textThe overall aim of this PhD thesis is to improve the investigation of the microplastics (MPs) presence in marine ecosystems and pursue understanding their impacts on marine species. To achieve these aims the main themes discussed in this PhD thesis were divided according to two main lines of research and a Citizen Science project. The first line of research is focused on the monitoring and assessment of the level of microplastic pollution in the marine environment (Mediterranean Sea) focusing on surface water, subsurface water, and sediments. This topic was pursued evaluating the limits of the standard methodologies used in the monitoring framework, designing upgrades in traditional sampling strategies and testing innovative sampling tools to collect more and more ecologically relevant data. Particular attention was paid to the study of the subsurface layers of the water column (approx. 10 m). With the aim to produce innovative knowledges and more data to better understand MPs dynamics and behavior, sampling strategy to collect samples from depth water was improved. In addition, the results obtained has allowed to compare depth with the surface to better describe the accumulation pattern of the MPs in the marine environment. Not only the sampling strategies were improved, but the laboratory procedurals analysis was implemented too. Even nowadays the laboratorial protocols employed in samples proceeding are globally widespread. The presence of globally shared standardized protocol is still missing. In fact, the personalized protocol that exists nowadays for the MPs detection analysis, producing an extremely variability in data from all over the world, makes it difficult to compare to each other. In the current thesis the procedural strategy adopted, was focused on enhancing the MPs extraction from the samples either from surface water, subsurface layer of the water column and sediments, with the aim to achieve the better strategy to propose a universal protocol of extraction. The achievement of the presented aims regarding sampling strategy and procedural analysis were pursued thanks to three sampling campaigns performed in the Mediterranean Sea, described in the first chapter that offers the possibility to test the designed upgrades. In addition, results obtained from the three sampling campaigns were used as point of comparison to confirm the actual efficiency of the adopted upgrades. Data obtained highlight that MPs and microfiber (MFs) distribution in the marine environment was not uniform, conversely it is subjected to a patchy distribution pattern. An accumulation of plastic is observed in sediments too, especially for those plastic particles composed in high density polymers (i.e. PET and PVC) and fibers. The second line of research is aimed to test the ecotoxicological effect of natural weathered plastic leachates on a battery of marine model organisms. To achieve this goal, a battery of traditional and innovative marine model organisms was adopted, and innovative endpoints were investigated. Leachates are a long-lasting threat of our era, caused by the long-term permanence of plastic in the environment and their consequently degradation. However, the investigation in the effects caused by plastic leachates is still poorly understood. Most of the studies in this context were focused on MPs leachates obtained by artificial aged plastic, avoiding the effect of exposure to the natural environment. Conversely, in the ecotoxicological study proposed in this thesis the toxicity of environmental aged plastics collected in different areas of the European marine compartment was investigated. Plastic collected in the field were secondly micronized in order to propose a more realistic scenario. Then MPs obtained have been leached and tested at different concentration. The ecotoxicological investigations pursued in this context were aimed to better define the ecological risk to which marine organisms are exposed and to define the possible response that organisms can produce as effect of the interaction with MPs. In addition, a Weight of Evidence (WOE) model was performed in collaboration with the Polytechnical University of Marche (UNIVPM), with the aim of better define the environmental hazard of the tested leachates. Our findings pointed out that plastic weathered in natural conditions are able to release leachates solutions that affect the behavioural end-point of different marine organisms with a degree of environmental hazard between absent and slight. Finally, the third chapter of this thesis is dedicated to a Citizen Science project aimed to test an innovative sampling strategy to monitor MPs accumulation in nearshore. While many studies have investigated beached and floating microplastics (size < 5 mm) in surface waters offshore, there is almost no information on floating microplastics in surface waters at less than a few hundred meters from the coastline, where the largest plastic mass flux is suspected to occur. Due to the extreme proximity to coastal sources of pollution: tourism activities, riverine mouth systems, wastewater treatment plants and high populated cities centers coupled with the high morphological variability of the coast, the near coast environment is interested in predicted accumulation of marine debris. At the same time the coastal line is not approachable with the boats usually used by the researchers for the monitoring of MPs in open sea, caused by legislative restrictions and practical difficulties. With this purpose the citizen science project here shown was aimed to test an innovative sampling strategy to monitor MPs pollution in nearshore by using a less impactful sampling method. This project in fact, proposes to the citizens involved to participate in the collection of nearshore surface water samples by using the innovative Minimanta net, a smaller and lightweight version inspired to the traditional one. This reduced device allows to tow it from floating gears like kayaks, that are less impacting and more agile to manage in nearshore environment. Coupled with this aim the second objective of the project was to increase the awareness and the responsibility of the participants in plastic pollution theme, to promote a sustainable way of life
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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