1,721,068 research outputs found
Characterising carbon cycle perturbations in the Cenomanian western interior seaway of North America
No full textAs current global temperatures continue to rise at an accelerated pace, it is becoming increasingly important to examine how the planet has responded to previous periods of global warming in order to gain valuable insights into how the Earth system may react in the future. The mid-Cretaceous (~101-91 Ma) provides an excellent case study of a prolonged greenhouse climatic state, where high rates of oceanic crust production and enhanced large igneous province-related volcanism released vast quantities of greenhouse gases into the atmosphere. Consequently, global temperatures reached their highest level for the past 450 Myr during the Cenomanian to Turonian stages, and peak sea levels led to the development of epeiric seas such as the Western Interior Seaway (WIS), which extended southwards from the northern Boreal Ocean, across central North America, and into the Tethys Ocean. Superimposed upon this greenhouse climate were a series of even more extreme climate perturbations, of which Oceanic Anoxic Event 2 (OAE 2), spanning the Cenomanian-Turonian boundary (94.1 Ma), was the most prominent, globally widespread, extreme climatic event of the Late Cretaceous. OAE 2 represents a major global carbon cycle perturbation, during which enhanced marine productivity coupled with the expansion of oxygen minimum zones across global oceans led to the extensive deposition of organic-rich black shale deposits. An earlier Mid-Cenomanian Event (MCE I; ~96.5 Ma) is taken to be a precursor to OAE 2, as it marks the beginning of a ~2 Myr oceanographic reorganisation during which bottom waters started to become increasingly oxygen-depleted. MCE I is identified on a global scale by a distinct dual-peaked positive carbon isotope excursion. However, with little evidence of widespread organic-rich mudrock deposition, most studies of MCE I are from carbonate-rich successions, thus limiting the range of analyses that can be undertaken. Here, a high-resolution, integrated organic and inorganic multi-proxy study of the Rebecca K Bounds-1 core from western Kansas has been undertaken in order to elucidate environmental and oceanographic changes during MCE I and the interval leading up to OAE 2 in the central-eastern WIS. MCE I is identified in an organic-rich sequence through a dual-peaked, positive organic carbon isotope excursion (MCE 1a and MCE 1b, respectively), and is determined to coincide with the establishment of a fully connected seaway that extended from the northern Boreal Ocean to the Tethyan Ocean in the south via the WIS in the mid-Cenomanian, as evidenced by diversified palynological, foraminiferal, and geochemical changes between MCE 1a and MCE 1b. Periodically enhanced planktic productivity is linked to ~50 kyr obliquity cycles across MCE I through cyclostratigraphic analysis. This heightened productivity is attributed to the strengthening of meridional winds during obliquity maxima, which may have increased upwelling-related nutrient input into Tethyan surface waters in equatorial regions. Palynological, redox-sensitive trace metal, lipid biomarker, and sedimentological data reveal that a complex dynamic oceanographic system prevailed in the central region of the WIS, with mixed early Cenomanian Tethyan-Boreal waters eventually being replaced by a northward migrating Tethyan water mass in the mid- to late Cenomanian. This situation prevailed until OAE 2 set in, when a rapid southward incursion of Boreal waters extended as far as the southern margin of the seaway. This multi-faceted study provides a new in-depth, high-resolution example of how Earth systems and environmental conditions reacted to periods of stressed, greenhouse climatic conditions
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
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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