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Wpływ transformacji materii organicznej odwodnionych utworów torfowych na zasoby i formy fosforu glebowego
No full textWydział Agrobioinżynierii i Nauk o ZwierzętachAbstract: The soil study was conducted on drained peat bogs in the region of the lower reaches of the Wieprz-Krzna Canal in Polesie Lubelskie. The primary objective of the study was to assess the transformation of organic matter and phosphorus in drained peat soils. Seven characteristic soil profiles (Murshic Histosols) were selected for the study. Soil material taken from 34 organic soil levels (peat and muck) was subjected to laboratory tests. Basic analyses of physical and chemical properties of the soil were conducted: volumetric density, ash content, soil moisture, porosity, pH, soil organic matter content, total content of C, N, P, Fe, Mn, Al, Ca and Mg. Phosphorus resources in the studied soils were determined. Sequential fractionation of carbon compounds was performed and the following organic matter fractions were obtained: after decalcification, bitumens, humic substances, humic acids, fulvic acids, post-extraction residue. Sequential fractionation of soil phosphorus was carried out and the following forms were obtained:
labile (accessible) loosely-bound or adsorbed;
sensitive to changes in redox potential, bound on the surface of hydrated oxides and hydroxides of iron (III) and manganese (IV), released under reducing conditions;
mineral and organic forms (metal oxides bound phosphorus, in apatites and carbonates, organic labile forms of phosphorus);
humic substances bound forms and other polymorphic forms of phosphorus;
phosphorus in the residual fraction, very stable organic and mineral phosphorus compounds. In statistical calculations, descriptive statistics were used: arithmetic mean, minimum value, maximum value, standard deviation, coefficient of variation. The values of the examined parameters in particular soil levels were compared using one-way analysis of variance and Tukey's post-hoc test (for different N). The relationship between the examined parameters was expressed in the form of a simple correlation coefficient (r). The soil phosphorus resources in the studied organic soils ranged from 166 to 237 g/m². Greater resources were found in organic soils located closest to the Wieprz-Krzna Canal, i.e. those more drained and transformed in the process of peat decomposition. The result of the organic matter decomposition process is a significant increase in phosphorus content and a narrowing of the carbon to phosphorus ratio (CT/PT). The processes of organic matter transformation and decay resulted in a large profile differentiation of soil phosphorus forms. In addition to mineralisation and humification of organic matter, iron, manganese and aluminium compounds have been proven to be important in soil phosphorus binding processes. The process of organic matter decomposition contributed to the increase in the share of assimilable (labile) forms of phosphorus, forms bound on the surface of iron (III) and manganese (IV) oxides and hydroxides (released under reducing conditions) as well as mineral and organic forms extracted with 0.5 M HCl. In the studied soils, phosphorus compounds released in the mineralisation processes of organic matter and phosphorus from mineral fertilization are bound primarily by humic substances as well as iron, manganese and aluminium compounds. The risk of the phosphorus migration can be increased by the reduction of chemical compounds containing phosphorus in the event of re-hydration of the area. Phosphorus binding by stable humic substances can be a factor limiting the absorption of soil phosphorus, but also limiting the risk of phosphorus dispersion. The de-watering of the studied area and the analysis of physical and chemical properties of the soil levels suggest that the evolution of the studied soils proceeds towards further deepening of the processes of organic matter decomposition and mineralisation as well as the growth and deepening of the soil phosphorus accumulation zone.Streszczenie: Badania gleboznawcze prowadzono na odwodnionych torfowiskach w rejonie dolnego biegu Kanału Wieprz-Krzna na Polesiu Lubelskim. Podstawowym celem była ocena transformacji materii organicznej i fosforu w odwodnionych glebach torfowych. Do badań wytypowano 7 charakterystycznych profili glebowych (Murshic Histosols). Szczegółowymi badaniami laboratoryjnymi objęto materiał glebowy pobrany z 34 organicznych poziomów glebowych (torfowych i murszowych). Wykonano podstawowe analizy właściwości fizycznych i chemicznych gleby: gęstość objętościowa, popielność, wilgotność gleby, porowatość, odczyn, zawartość substancji organicznej gleby, całkowitą zawartość C, N, P, Fe, Mn, Al, Ca i Mg. Ustalono zasoby fosforu w badanych glebach. Wykonano sekwencyjne frakcjonowanie związków węgla i uzyskano następujące frakcje substancji organicznej: po dekalcytacji, bituminów, substancje humusowe, kwasy huminowe, kwasy fulwowe, poekstrakcyjna pozostałość. Przeprowadzono sekwencyjne frakcjonowanie fosforu glebowego i uzyskano następujące formy:
− labilne (dostępne) luźno związane bądź zaadsorbowane;
− wrażliwe na zmianę potencjału redox, związane na powierzchni uwodnionych tlenków i wodorotlenków żelaza (III) i manganu (IV), uwalniane w warunkach redukcyjnych;
− formy mineralne i organiczne (fosfor związany przez tlenki metali, w apatytach i węglanach, organiczne labilne formy fosforu);
− formy związane przez substancje humusowe oraz inne polimorficzne formy fosforu;
− fosfor we frakcji rezydualnej, bardzo trwałe organiczne i mineralne związki fosforu.
W obliczeniach statystycznych zastosowano statystyki opisowe: średnia arytmetyczna, wartość minimalna, wartość maksymalna, odchylenie standardowe, współczynnik zmienności. Wartości badanych parametrów w poszczególnych poziomach glebowych porównano jednoczynnikową analizą wariancji i testem post-hoc Tukeya (dla różnych N). Zależności pomiędzy badanymi parametrami wyrażono w postaci współczynnika korelacji prostej (r). W badanych glebach organicznych zasoby fosforu glebowego wynosiły od 166 do 237 g·m2. Większe zasoby stwierdzono w glebach organicznych zlokalizowanych najbliżej Kanału Wieprz-Krzna tj. bardziej osuszonych i przeobrażonych w procesie murszenia. Efektem procesu rozkładu materii organicznej jest istotny wzrost zawartości fosforu i zawężenie stosunku węgla do fosforu (CT/PT). Efektem procesów transformacji materii organicznej i murszenia było duże zróżnicowanie profilowe form fosforu glebowego. Obok mineralizacji i humifikacji materii organicznej istotne znaczenie w procesach wiązania fosforu glebowego udowodniono dla związków żelaza, manganu i glinu. Proces rozkładu materii organicznej przyczynił się do wzrostu udziału form przyswajalnych (labilnych) fosforu, form związanych na powierzchni tlenków i wodorotlenków żelaza (III) i manganu (IV) (uwalnianych w warunkach redukcyjnych) oraz form mineralnych i organicznych wydzielonych 0,5M HCl. W badanych glebach uwalniane związki fosforu w procesach mineralizacji materii organicznej oraz fosfor pochodzący z nawożenia mineralnego jest wiązany przede wszystkim przez substancje humusowe oraz związki żelaza manganu i glinu. Istotnym mechanizmem zwiększającym ryzyko migracji fosforu może być redukcja związków chemicznych zawierających fosfor przy ponownym zawodnieniu terenu. Wiązanie fosforu przez trwałe substancje humusowe może być czynnikiem ograniczającym przyswajalność fosforu glebowego, ale także ograniczającym ryzyko rozpraszania fosforu. Odwodnienie badanego terenu oraz analiza właściwości fizycznych i chemicznych poziomów glebowych sugerują ewolucję badanych gleb w kierunku dalszego pogłębiania procesu murszenia i mineralizacji substancji organicznej oraz wzrostu i pogłębiania strefy nagromadzenia fosforu gleboweg
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
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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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