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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
Massive volcanic domes on Venus and the mobilisation of crystal mush: insights from the Troodos Ophiolite, Cyprus
No full textVenus is widely regarded as Earth’s ‘sister’ planet, given similarities in size, mass,
density, chemical composition, and also their proximity. However, there are also striking differences between the two planets. The surface of Venus is dominated by volcanic and tectonised volcanic terrains. Volcanism on Venus is, presumably, largely plume-related due to the absence of evidence for plate tectonic processes. Under the extreme high temperatures and pressures of the Venusian surface, lava flows can extend for hundreds to thousands of kilometres. Steep-sided domes are among the most starkly discernible volcanic landforms on the surface of Venus, given their gigantic size (e.g., 0.12–1.73 km in height, and 8.3–61.8 km in diameter) and peculiar shape, compared to other volcanic features. Those domes are believed to be volcanic edifices, characterised by steep margins, and relatively smooth, flat upper surfaces, exhibiting a circular shape in plan view. Given their distinct morphology, they are important in (1) understanding the range of magmatic processes operating on Venus, and (2)
elucidating geological evolution of planets lacking plate tectonics.
Despite their significance, there remains debate regarding the formation mechanisms of these domes. Physical models suggest that Venusian steep-sided domes require eruption of highly viscous liquids to explain their morphologies. This has led several authors to suggest that they represent eruption of SiO2-rich magmas at relatively low temperatures. However, other authors have argued that radar characteristics of steep-sided domes are inconsistent with eruption of very SiO₂-rich materials, and alternatively suggested that they represent eruption of more mafic liquids. In this scenario, high crystallinities may account for unusually high viscosities evidenced by dome morphology. Bulk viscosity of magmas depends on many factors, including composition (e.g., SiO₂ content and extent of polymerisation), volatile content, crystal content, and most importantly temperature. The overall aim of this study is to assess physical models of Venusian steep-sided dome formation by assessing the validity and implications of constraints on lava viscosity which they provide.
Work is divided into two Sections and four chapters. In Section 1 (Chapter 2), I model magma fractionation to calculate the full range of liquid compositions and bulk viscosity of magmas, which is compared to the viscosity thresholds from physical models. A key finding from this work is that high crystal contents are required to account for formation of high viscosity lavas on Venus. In Section 2 (Chapter 3 to 5), I conduct fieldwork to characterise a terrestrial analogue of eruption of high crystallinity picritic lavas in the Troodos Ophiolite, Cyprus. Using geochemical data, petrological and thermodynamic modelling, and field
observations, I investigate the formation and eruption mechanisms, parental magma compositions, and viscosities of picrites. Information from this section is then used to further assess steep-sided dome formation on Venus and controls of crystallinity on magma viscosity.
In Chapter 2, I implement thermodynamic modelling using the rhyolite-MELTS model to constrain magma compositions, and magma viscosities based on various viscosity parameterisations, using bulk compositions inferred from Venera 13 (alkaline basalt) and Venera 14 (low alkali basalt) Soviet lander data. Viscosities are then compared to viscosity thresholds from published physical models of Venusian dome formation. Extensive (>85–90%) fractional crystallisation or equilibrium melting processes alone fail to produce magmas with viscosities required to account for steep-sided domes. The presence of H₂O during equilibrium crystallisation substantially modifies magma composition (e.g., SiO₂), and decreases solidus temperature, contributing to an increase of liquid viscosity. However, this effect is less significant than the direct control of H₂O as a network modifier in lowering viscosity. Instead, our results reveal that crystal contents of >60 vol.% are invariably required to produce sufficiently high magma bulk viscosities. Such high crystallinities probably require eruption of crystal-rich magma followed by surface crystallisation, possibly enhanced by degassing and undercooling.
To further constrain the eruption mechanisms of high crystallinity magma, in Chapter 3, I conduct fieldwork to observe field relations and collect a suite of representative high crystallinity picritic bodies (e.g., lava flows and a dome) from the Margi (Mαρκί, sometimes referred to as Marki) region, Troodos Ophiolite, Cyprus. These picrites represent a series of mafic/ultramafic lava flows, with groundmasses ranging from glassy to holocrystalline/vitrophyric texture and typically containing variable, but very high concentrations of up to cm-sized olivine. The crystal content from different picrite bodies can vary from 36 to 66 vol.%. I describe field relations, petrology, and geochemistry of a number of these picrite bodies, including olivine (+spinel and melt inclusion) compositions, erupted glass compositions and whole rock data. These picrites are discrete units within the upper pillow lava sequence, with crystal contents that imply open-system crystal accumulation. Variations in composition and olivine crystal cargo imply that bodies have discrete compositions, and close proximity of picrites to extensional faults supports a model where extrusion of crystal mush onto the palaeo-seafloor was facilitated by rifting and tapping of small magmatic systems. However, olivine-spinel equilibration temperatures imply minimal re-equilibration, favouring a model of hot crystal mush storage in the crust.
In Chapter 4, based on olivine-hosted melt inclusion (MI) data, I use petrological modelling to constrain parental magma compositions, and petrogenesis of high crystallinity lavas. I also perform forward fractional crystallisation and partial melting using rhyolite-MELTS to constrain conditions under which olivine crystallisation occurred. Results are discussed within the framework of glass (e.g., erupted liquids), olivine and spinel compositional data. The key findings are (1) crystal-rich magmas are likely formed by magma recharging and repetitive fractionation and concentration of olivine crystals within magmatic systems at less than 0.4 GPa (i.e., ~15 km depth); (2) at least 40% of olivine phenocrysts within picrites are in equilibrium with liquids in which they have erupted, and that picrites are likely formed both by fractionation of olivine, and remobilisation of xenocrysts; (3) Erupted picrites represent a mixture of variably evolving melts (closed system fractionation) and olivine from a mush-rich magmatic system, with the average Fo content from different picritic bodies ranging between Fo₈₉ to Fo₉₁; (4) Parental magmas to both erupted liquids and olivines had variable compositions, including both variations in primary compositions and due to variable extents of sulfide saturation during early stages of olivine crystallisation.
In Chapter 5, I perform viscosity calculations based on glass compositions, H2O content, crystallinity, and crystal size distribution or morphology measured directly from picrite samples to estimate the viscosity of picritic flows and lavas in Margi. Although these lavas have very high crystal contents, calculated viscosities are relatively low due to the low viscosity of erupted liquids, which is, in turn, a function of mafic compositions, high water contents and high erupted temperatures. As a result, the picrite dome at Margi is not a good analogue for investigating the eruption mechanisms for Venusian domes, although picritic bodies at Margi do provide insight into the formation and eruptibility of high crystallinity magma. I further compile dome morphologies for all terrestrial lava domes from basaltic to rhyolitic compositions and other extra-terrestrial lava domes. Venusian steep-sided domes have a smaller aspect ratio (height/width) than 90% of terrestrial lava domes, indicating that direct
comparison between terrestrial domes and Venusian steep-sided domes is challenging given (1) their large difference in volumes and (2) the difference in surface environments between the two planets (e.g., surface temperature, pressure, atmosphere compositions, etc). As such, greater emphasis should instead be placed on improving models of dome formation under
Venusian conditions, and especially, on considering the key role of crystallinity, lava cooling rate as well as composition in controlling lava viscosity and dome morphology
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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