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Microplastic on the example of siberian sturgeon (Acipenser baerii) and European catfish (Silurus glanis L) grown in the RAS-system
No full textMagistritöö
Kalanduse ja rakendusökoloogia õppekavalPublitseeritud teadustöödest lähtudes on kõigil veeorganismide rühmadel suur oht mikroplastiga kokkupuuteks. Toiduahela kaudu veeorganismidesse sisenev mikroplast jõuab lõpuks ka inimeste toidulauale, ohustades otseselt inimeste tervist.
Kuigi plastisaaste kontsentratsioone keskkonnas on mõõdetud mitmesugustes maatriksites, on teavet mikro- ja nanoplastide esinemise kohta vee korduvkasutusega vesiviljelussüsteemides (RAS) vähe. Mikro- ja nanomõõdus plastisaaste on samas suurusjärgus paljude veeorganismidega ning sellest tulenevalt saavad toiduobjektiks filtreerijatele, detrivooridele ja settetoidulistele organismidele, samuti vähilaadsetele ja kaladele.
Mikroplasti reostust looduslikes kalavetes on praeguseks põhjalikult uuritud kuid, millisel määral ja ulatuses ning milliste tegurite koosmõjul antud probleem ilmneb RAS-i intensiivse tootmise käigus on suures osas ebaselge. Erinevas mikromõõdus plastisaaste vesiviljelusüksustesse sattumise teed võivad hõlmata nii heit- kui ka torude kaudu voolavat vett, lagunevaid vesiviljelusseadmeid, kalasööta kui kalapüügivahendeid. Keskkonnaohutuse, majandusliku tõhususe ja toiduohutuse kaalutlustel on vajalik igakülgne arusaam vesiviljeluse mikroplastireostusest intensiivse tootmise käigus. Käesoleva uurimistöö eesmärk oli uurida mikroplastide esinemist RAS-majandite süsteemi vees ja kalade elundites, määrata polümeerid ning kvantifitseerida nende kontsentratsioon.
Uurimistöös analüüsiti kolmest, suletud vee korduvkasutusega kalamajandist pärit magevee, siirde- ja poolsiirde kalade, euroopa säga (Silurus glanis L.) ja siberi tuur (Acipenser baerii B.) seedetrakti ja hingamiselundeid, kalabasseinidest pärit veeproove ning tuvastati mikroplasti keemiline kompositsioon. Tuvastatud mikroplasti domineeriv kuju oli kild, värvidest must, lilla ja sinine. FTIR-spektroskoopia abil määratud polümeeri tüüpide hulgas olid polüamiid (PA) ja polüvinülideenkloriid (PVDC) levinuimad.
Laboris läbi viidud katsete eesmärk oli selgitada välja:
1) kas ja millises ulatuses võib Eesti kolmes RAS majandis kasvatatavatel kaladel tuvastada mikromõõdus plastisaastet;
2) millised on potentsiaalsed mikroplasti vesiviljelusüksustesse sattumise teed uuritavates kalamajandites.
Tõestatud said hüpoteesid:
- RAS-süsteem saastub süsteemi komponentidest tuleneva plastireostusega;
- RAS-süsteemis leidub plastireostust mikroplasti suuruse tasemel;
- RAS majandi kala seedetrakt ning hingamiselundid reostuvad mikroplastiga.
Uuringu tulemused võivad anda võrdlusaluse mikroplastide edasiseks jälgimiseks ning eemaldamiseks erinevatest kalakasvatussüsteemidest.Microplastic pollution has become a major global environmental issue. Since fish is an important source of animal protein for human beings, the occurrence and potential impacts of microplastics in fishes deserve very special attention. For environmental safety, economic efficiency and food safety considerations, a comprehensive understanding of microplastic pollution in aquaculture is necessary. External environmental inputs and aquaculture processes are sources of microplastics in aquaculture. The aim of this research was to investigate the presence of microplastics in RAS farms, to identify the polymers present in the water of the system as well as in the organs of the fish, and to quantify their concentration.
The research analyzed the digestive and respiratory organs of Wels catfish (Silurus glanis L.) and Siberian sturgeon (Acipenser baerii B.), water samples from fish ponds, and identified the chemical composition of microplastics. The dominant shape of microplastics detected was fragment, with colors of black, purple and blue. Among the types of plastic polymers determined by FTIR spectroscopy, polyamide (PA) was the most common type of polymer. The experiments carried out in the laboratory were designed to find out:
1) whether and to what extent microscale plastic contamination can be detected in fish farmed in three RAS farms in Estonia;
2) the potential pathways for microplastics to enter the aquaculture units in the fish farms under study.
The hypotheses were proved:
- The RAS system is contaminated by plastic pollution from system components;
- Plastic pollution is present in the RAS system at the microplastics size level;
- The digestive tract and respiratory tract of fish in RAS farms are contaminated with microplastics.
The results of the study may provide a benchmark for further monitoring and removal of microplastics from different fish farming systems
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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