1,720,954 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Genetic analysis and construction of a genetic map of Russian Dandelion (Taraxacum koksaghyz) as an alternative resource crop for natural rubber
No full textDie globale Naturkautschuk-Versorgung ist momentan von einer einzigen Art (Hevea brasiliensis) abhängig, was sie anfällig für Krankheiten und wirtschaftlichen Druck macht. Diese Dissertation begegnet dem dringenden Bedarf an alternativen Kautschukquellen durch die genetische Verbesserung des Russischen Löwenzahns (Taraxacum kok-saghyz, TKS), einer vielversprechenden Pflanze für gemäßigte Zonen. Hauptziel war die Entwicklung genomischer Werkzeuge zur Beschleunigung der Züchtung ertragreicher TKS-Sorten.
Zunächst wurde die genetische Diversität von TKS und anderen Taraxacum-Arten mittels AFLP-Marker analysiert. Die Ergebnisse bestätigten die genetische Abgrenzung von TKS gegenüber verwandten Arten wie dem gewöhnlichen Löwenzahn, zeigten aber auch nur eine geringe bis mäßige genetische Vielfalt im bestehenden Zuchtmaterial auf. Dies verdeutlicht die Notwendigkeit, strategisch neues pflanzengenetisches Material zu integrieren, um einen langfristigen Zuchterfolg zu sichern.
Eine biparentale F1-Kartierungspopulation, erzeugt aus Kreuzungen von Eltern mit hohem und niedrigem Kautschukgehalt, wurde in mehrjährigen Feldversuchen an drei Standorten untersucht. Dabei zeigte sich eine enorme phänotypische Variation des Kautschukgehalts (0,1 % bis 24 %). Die hohe Heritabilität des Merkmals ( = 0,656) belegt eine starke genetische Kontrolle und signalisiert ein hohes Potenzial für die züchterische Selektion.
Im Kern dieser Arbeit stand die Erstellung der ersten hochauflösenden genetischen Karten für TKS mittels Genotyping-by-Sequencing (GBS). Es entstanden zwei detaillierte elterliche Karten mit jeweils acht Kopplungsgruppen, entsprechend der haploiden Chromosomenzahl von TKS. Diese Karten bildeten die Grundlage für die Analyse von Quantitative Trait Loci (QTL), um die für die Kautschukproduktion verantwortlichen Genomregionen zu identifizieren.
Die Analyse identifizierte drei statistisch signifikante Major-QTL für den Kautschukgehalt. Zwei davon lagen auf der mütterlichen und einer auf der väterlichen Karte. Die einzelnen Loci erklärten zwischen 9,1 % und 15,4 % der phänotypischen Varianz. Ein Abgleich mit dem physischen Genom bestätigte eine bekannte QTL-Region auf Chromosom A1 und identifizierte darüber hinaus eine bisher unbekannte QTL-Region auf Chromosom A7.
Zusammenfassend liefert diese Forschung entscheidende genomische Werkzeuge für die TKS-Züchtung. Die hochauflösenden Karten und identifizierten QTL sind eine fundamentale Ressource für die moderne Züchtung. Die mit den QTL verknüpften SNP-Marker ermöglichen die Entwicklung von Werkzeugen für die markergestützte Selektion (MAS). Damit können Züchter überlegene Pflanzen bereits im Keimlingsstadium identifizieren, was die Entwicklung kommerziell rentabler TKS-Sorten erheblich beschleunigt und zur Sicherung einer nachhaltigen Naturkautschuk-Versorgung beiträgt.The global supply of natural rubber is critically dependent on a single species, Hevea brasiliensis, leaving it vulnerable to disease and economic pressures. This dissertation addresses the urgent need for alternative rubber sources by focusing on the genetic improvement of Russian Dandelion (Taraxacum kok-saghyz, TKS), a promising temperate-climate resource crop. The primary goal was to develop genomic tools to accelerate the breeding of high-yielding TKS varieties.
To achieve this, the study first assessed the genetic landscape of TKS and related species. Using Amplified Fragment Length Polymorphism (AFLP) markers, the research confirmed that TKS is genetically distinct from related species like the common dandelion, while also revealing low to moderate genetic diversity within existing breeding germplasm. This highlights a need to strategically incorporate new genetic material to ensure long-term breeding success.
A biparental F1 mapping population was created by crossing high and low rubber-producing parent plants. Extensive multi-year field trials across three different locations revealed significant phenotypic variation for rubber content, ranging from 0.1 % to 24 %. A high broad-sense heritability ( ) of 0.656 was calculated for this trait, indicating strong genetic control and a high potential for improvement through selective breeding.
The core of the project involved creating the first high-resolution genetic maps for TKS using Genotyping-by-Sequencing (GBS). This resulted in two detailed parental maps. Each resolved into eight linkage groups corresponding to the haploid chromosome number of TKS. These maps served as the foundation for quantitative trait loci (QTL) analysis to identify genomic regions controlling rubber production.
The analysis successfully identified three major, statistically significant QTL associated with rubber content. Two QTL were located on the maternal map and one on the paternal map, with individual loci explaining between 9.1 % and 15.4 % of the phenotypic variance. By aligning these genetic findings with the TKS physical genome, the study confirmed a previously reported major QTL region on chromosome A1 and discovered a novel major QTL on chromosome A7.
In conclusion, this research provides a vital genomic toolkit for TKS improvement. The high-resolution maps and identified QTL for rubber content are foundational resources for modern breeding. The SNP markers linked to these QTL can now be used to develop tools for marker-assisted selection (MAS), enabling breeders to identify superior plants at an early stage, thereby accelerating the development of commercially viable TKS cultivars and helping to secure a sustainable future for natural rubber
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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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