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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
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
First evidence of epithelial transport in tardigrades:a comparative investigation of organic anion transport
No full textSUMMARYWe investigated transport of the organic anion Chlorophenol Red (CPR) in the tardigrade Halobiotus crispae using a new method for quantifying non-fluorescent dyes. We compared the results acquired from the tardigrade with CPR transport data obtained from Malpighian tubules of the desert locust Schistocerca gregaria. CPR accumulated in the midgut lumen of H. crispae, indicating that organic anion transport takes place here. Our results show that CPR transport is inhibited by the mitochondrial un-coupler DNP (1 mmol l–1; 81% reduction), the Na+/K+-ATPase inhibitor ouabain (10 mmol l–1; 21% reduction) and the vacuolar H+-ATPase inhibitor bafilomycin (5 μmol l–1; 21% reduction), and by the organic anions PAH (10 mmol l–1; 44% reduction) and probenecid (10 mmol l–1; 61% reduction, concentration-dependent inhibition). Transport by locust Malpighian tubules exhibits a similar pharmacological profile, albeit with markedly higher concentrations of CPR being reached in S. gregaria. Immunolocalization of the Na+/K+-ATPase α-subunit in S. gregaria revealed that this transporter is abundantly expressed and localized to the basal cell membranes. Immunolocalization data could not be obtained from H. crispae. Our results indicate that organic anion secretion by the tardigrade midgut is transporter mediated with likely candidates for the basolateral entry step being members of the Oat and/or Oatp transporter families. From our results, we cautiously suggest that apical H+ and possibly basal Na+/K+ pumps provide the driving force for the transport; the exact coupling between electrochemical gradients generated by the pumps and transport of ions, as well as the nature of the apical exit step, are unknown. This study is, to our knowledge, the first to show active epithelial transport in tardigrades.</jats:p
Rearrangement of organs and cells during anhydrobiotic tun formation in <i>Richtersius coronifer</i>.
No full text<p>Light microscopy of <b>A</b>. active, hydrated animal (lateral view) and <b>B</b>. a tun (ventral view) showing the rearrangement of major anatomical structures during tun formation. Note the compact body shape of the tun. Dashed circles indicate areas of the midgut (mg), gonads (go) and pharyngeal bulb (pb), respectively. The degree of longitudinal contraction is ultimately limited by the length of the rigid stylets (st). The pharyngeal bulb is for the most part repositioned in the dorsomedian plane. Maximum projection image of a confocal z-series of <b>C</b>. hydrated DAPI stained specimen (lateral view), and D. DAPI stained tun (ventral view) demonstrating the reposition of cell nuclei during tun formation. Scanning electron micrograph of <b>E</b>. a hydrated specimen (lateral view) and <b>F</b>. a tun (dorsal view) revealing the extensive changes in external morphology associated with formation of the tun. A↔P, anterior-posterior axis; br, brain; gI-gIV, ventral ganglia; mo, mouth. Scale bars = 100 μm. </p
Myoanatomical changes in <i>Richtersius coronifer</i> during tun formation.
No full text<p><b>A</b>-<b>D</b>. 3D reconstructions of the tardigrade musculature as visualized by fluorescent phalloidin. <b>A</b>. Lateral view of active (hydrated) state showing details of the dorsal, lateral and leg musculature. <b>B</b>. Ventral view showing details of the ventral longitudinal musculature in the active state. <b>C</b>. Dorsal view of the myoanatomy of the tun (dehydrated) state D. Ventral view of the myoanatomy of the tun. <b>E</b>-<b>F</b>. Scanning electron microscopy (SEM) of animals in the tun state showing the corresponding external morphology of the myoanatomy presented in C and D. <b>E</b>. Dorsal view of the tun. <b>F</b>. Ventral view of the tun. <b>G</b>. SEM of an animal incubated in 1.0 mg/ml phalloidin for 24 h and subsequently dehydrated. The animal failed to form a tun upon dehydration, and collapsed into a flattened shape. A similar collapse was seen in DNP exposed animals upon dehydration. <b>H</b>. Corresponding maximum projection image of a confocal z-series of the musculature of a specimen incubated in 1.0 mg/ml phalloidin for 24 h before dehydration. A↔P, anterior-posterior axis; A-W, dorsal attachment sites; τ<sub>0</sub>-τ<sub>4</sub>, lateral attachment sites; la-g, ventral intermediate attachment sites; 1-7, ventromedian attachment sites; pb, pharyngeal bulb; ω1-Ω, attachment sites of muscles associated with the pharyngeal bulb; stm, stylet muscles. Solid circles indicate lateral attachment sites, solid squares show ventral intermediate attachment sites, while dashed circles indicate areas of the legs. Scale bars = 100 μm.</p
Schematic representation of the muscles involved in tun formation in <i>Richtersius coronifer</i>.
No full text<p>Schematic representation illustrating contraction of muscles during the transition from the active (hydrated) to the tun (dehydrated) state. <b>A</b>. Ventral longitudinal musculature. <b>B</b>. Dorsal longitudinal musculature. <b>C</b>. Leg musculature. The dorsal longitudinal, ventral longitudinal, as well as lateral musculature are involved in reshaping the whole body during anhydrobiosis, and are consequently responsible for generating the compact body shape of the tun. Tun formation is moreover characterized by the withdrawal of the legs into the body cavity. Letters and numbers indicate specific muscle attachment sites (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085091#pone-0085091-g003" target="_blank">Figure 3</a>). </p
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