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Kadmiumaltistuksen havaitseminen Hydropsyche pellucidula -vesiperhostoukilla (Trichoptera: Hydropsychidae) hyperspektrikuvantamisen ja kidusvaurioiden avulla
No full textMetallipäästöt aiheuttavat vesistöissä eliöyhteisöille monenlaisia haittavaikutuksia, joita voidaan tutkia bioindikaattori- eli ilmentäjälajimenetelmin. Vesiperhostoukkia (Trichoptera) on käytetty virtavesien metallisaastumisen indikaattoreina, sillä ne kestävät metallialtistusta suhteellisen hyvin, mutta altistuksen seurauksena toukilla voi esiintyä morfologisia muutoksia, kuten kidusvaurioita tai pintakudoksen tummumista. Koska toisaalta vierasaineiden kudospitoisuusmittaus on usein työlästä ja toisaalta rakenteellisten muutosten arviointi altis subjektiiviselle harhalle, tavoitteenani oli kehittää objektiivinen ja kustannustehokas tapa selvittää metallialtistusta ja sen vaikutuksia pohjaeläimistä. Hyperspektrikuvantamisella (hyperspectral imaging, HSI) voidaan tutkia aineiden pitoisuusvaihteluja eri matriiseissa. Sitä hyödynnetään jo muun muassa maaperätutkimuksessa, maataloudessa ja elintarviketeollisuudessa. Tutkielmassani tutkin hyperspektrikuvantamisen soveltuvuutta kadmiumin havaitsemiseen Hydropsyche pellucidula -vesiperhostoukista. Toukkia altistettiin kadmiumkloridille 96 tuntia subletaaleissa pitoisuuksissa 9,9, 94,5, 880 ja 8996 µg Cd l-1. Toukat kuvattiin HSI-kameralla 500–665 nm aallonpituuksilla, niistä tutkittiin mikroskoopilla kidusten vauriot ja niiden Cd-pitoisuudet määritettiin. Kudosten ja altistusveden kadmiumpitoisuuden välillä oli positiivinen korrelaatio (Spearman, n = 74, r = 0,93, p < 0,001). Kidusvaurioita esiintyi kaikissa altistuspitoisuuksissa, mutta eniten pitoisuudessa 94,5 µg l-1. Kudosten kadmiumpitoisuudella ja kidusvaurioiden esiintymisellä ei havaittu yhteyttä (Spearman, n = 74, r = -0,034, p = 0,774). Hyperspektriaineiston perusteella toukkien hemolymfan trehaloosi- eli disakkaridipitoisuus korreloi negatiivisesti (Pearson, n = 30, r = -0,43, p < 0,05) kudosten kadmiumpitoisuuden kanssa. Takaruumiin tumma pigmentti, eumelaniini, runsastui (Pearson, n = 30, r = 0,61, p < 0,001) ja vaalea pigmentti, feomelaniini, väheni (Pearson, n = 30, r = -0,62, p < 0,001) kuvan spektrin kokonaisintensiteetin kasvaessa. Kudosten kadmiumpitoisuus nähtävästi vaikutti kokonaisintensiteettiin ja pigmenttisuhteisiin välillisesti, sillä kudospitoisuudella ei havaittu yhteisvaihtelua näiden muuttujien kanssa. Havaitut spektripiirteiden muutokset toukissa viittaavat stressi- tai immuunireaktioihin altistuksen seurauksena. Hyperspektrikuvantaminen vaikuttaa lupaavalta menetelmältä kadmiumaltistuksen havaitsemiseen, mutta sen laajempi käyttöönotto vaatii sisäänajoa eri lajeilla ja metalleilla.Detecting cadmium exposure from Hydropsyche pellucidula
(Trichoptera: Hydropsychidae) larvae using hyperspectral
imaging and incidence of gill anomalies.
The effects of metal pollution on aquatic biota can be studied using bioindicator methods. Caddis larvae (Trichoptera) are widely used to indicate metal contamination of stream waters since they are relatively tolerant to metal exposure, but show morphological responses, such as gill anomalies or darkening of surface tissue. Because the analyses of tissue concentrations are often quite laborious and evaluation of morphological responses liable to subjective error, my goal was to develop an objective, cost-efficient method to detect metal exposure and its effects from benthic macroinvertebrates. Hyperspectral imaging (HSI) can be used to detect concentrations of elements and substances in different matrices. HSI has applications already in soil research, agriculture and food industry. In this study, I tested the applicability of HSI in detecting sublethal Cd exposure of Hydropsyche pellucidula larvae. Larvae were exposed to CdCl2 for 96 hours, in Cd concentrations of 9.9, 94.5, 880 ja 8996 µg Cd l-1. The measured endpoints were the Cd-concentration of larvae and occurrence of gill anomalies. All larvae were imaged using 500-665 nm visible light wavebands. The measured tissue Cd concentration of the larvae correlated significantly with the exposure concentration (Spearman, n = 74, rs = 0.93, p < 0.001). Gill anomalies were present at all exposure concentrations, but were the most frequent at 94.5 µg Cd l-1. However, there was no association between the incidence of gill anomalies and the Cd tissue concentration (Spearman, n = 74, r = -0.034, p = 0.774). Based on the HSI results, the trehalose concentration (a disaccharide) in larval hemolymph decreased with increasing Cd tissue concentration (Pearson, n = 30, r = -0.43, p < 0.05). Pigmentation of larval abdomen changed as the total intensity of images increased; the relative amounts of eumelanin, a dark pigment, increased (Pearson, n = 30, r = 0.61, p < 0.001) and pheomelanin, yellow pigment, decreased (Pearson, n = 30, r = -0.62, p < 0.001) with increasing total intensity. It seems that tissue Cd concentration affected total intensity and pigment proportions indirectly, since tissue concentration did not correlate with these variables. The observed changes in spectral features suggest stress or immune reactions followed by Cd exposure. Based on the results, hyperspectral imaging is a promising technique for detecting Cd exposure from H. pellucidula, though more research with different species and metals is needed.unknown accessibilityei tietoa saavutettavuudest
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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