1,720,962 research outputs found
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
The Role of GAP-43 Phosphorylation in Axon Behavior in the Developing Zebrafish Visual System
Get PDFDeveloping neurons extend processes to specific targets and establish connections that are essential for future function of the nervous system. One of these processes, the axon, has a motile tip called a growth cone that rearranges its membrane-associated actin cytoskeleton to turn toward or away from environmental guidance cues. Growth associated protein 43 (GAP-43) is one of the most abundant proteins associated with axonal growth cone membranes and is known to modulate the formation and stability of the actin cytoskeleton during axon guidance. Protein kinase C (PKC)-mediated phosphorylation of GAP-43 on serine 42 regulates its interactions with actin. Phosphorylated GAP-43 stabilizes actin filaments in growth cones that are actively pathfinding. Using the developing zebrafish visual system to model axon growth and guidance, we determined the role of GAP-43 phosphorylation during retinal ganglion cell (RGC) axon emergence and growth by disrupting phosphorylation in vivo. In zebrafish embryos we induced the expression of a mutant version of GAP-43, GAP43s42, that has a serine to alanine substitution mutation at position 42. This dominant negative mutant GAP-43 cannot be phosphorylated by PKC. Overexpression of the GAP43s42a mutant early in visual system development gave rise to embryos in which the optic nerve appeared thinner. Further investigation revealed this phenotype was caused by defects in RGC differentiation and axon guidance errors within the retina. Overexpression of GAP43s42a later in development, when RGC axons are actively growing in the optic chiasm, resulted in a loss in the close association of axons in the optic nerve leading to defasciculation and aberrant axon trajectories. We conclude from these results that phosphorylation of GAP-43 plays an important role in regulating RGC differentiation, axon guidance, and axon fasciculation
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
The Role of GAP-43 Phosphorylation in Axon Behavior in the Developing Zebrafish Visual System
No full textDeveloping neurons extend processes to specific targets and establish connections that are essential for future function of the nervous system. One of these processes, the axon, has a motile tip called a growth cone that rearranges its membrane-associated actin cytoskeleton to turn toward or away from environmental guidance cues. Growth associated protein 43 (GAP-43) is one of the most abundant proteins associated with axonal growth cone membranes and is known to modulate the formation and stability of the actin cytoskeleton during axon guidance. Protein kinase C (PKC)-mediated phosphorylation of GAP-43 on serine 42 regulates its interactions with actin. Phosphorylated GAP-43 stabilizes actin filaments in growth cones that are actively pathfinding. Using the developing zebrafish visual system to model axon growth and guidance, we determined the role of GAP-43 phosphorylation during retinal ganglion cell (RGC) axon emergence and growth by disrupting phosphorylation in vivo. In zebrafish embryos we induced the expression of a mutant version of GAP-43, GAP43s42, that has a serine to alanine substitution mutation at position 42. This dominant negative mutant GAP-43 cannot be phosphorylated by PKC. Overexpression of the GAP43s42a mutant early in visual system development gave rise to embryos in which the optic nerve appeared thinner. Further investigation revealed this phenotype was caused by defects in RGC differentiation and axon guidance errors within the retina. Overexpression of GAP43s42a later in development, when RGC axons are actively growing in the optic chiasm, resulted in a loss in the close association of axons in the optic nerve leading to defasciculation and aberrant axon trajectories. We conclude from these results that phosphorylation of GAP-43 plays an important role in regulating RGC differentiation, axon guidance, and axon fasciculation.2016-12-2
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
