1,720,993 research outputs found
Glial cells of the developing amphioxus: a molecular study
No full textGlial cells play important roles in the development and homeostasis of metazoan nervous systems.
However, while their involvement in the development and function in the central nervous system (CNS) of
vertebrates is increasingly well understood, much less is known about invertebrate glia and the evolutionary
history of glial cells more generally. An investigation into amphioxus glia is therefore timely, as this
organism is the best living proxy for the last common ancestor of all chordates, and hence provides a
window on the role of glial cells development and function at the transition between invertebrates and
vertebrates. We report here our findings on amphioxus glia as characterized by molecular probes correlated
with anatomical data at the TEM level. The results show amphioxus glial lineages express genes typical of
vertebrate astroglia and radial glia and segregate early in development, forming what appears to be a
spatially separated cell proliferation zone positioned laterally, between the dorsal and ventral zones of
neural cell proliferation. Our study provides strong evidence for the presence of vertebrate-type glial cells
in amphioxus while highlighting the role played by segregated progenitor cell pools in CNS development.
There are implications also for our understanding of glial cells in a broader evolutionary context and
insights into patterns of precursor cell deployment in the chordate nerve cord
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
Impact of ocean warming on early development of the Mediterranean mussel Mytilus galloprovincialis: Effects on larval susceptibility to potential vibrio pathogens
No full textIn a global change scenario, ocean warming and pathogen infection can occur simultaneously in coastal areas, threatening marine species. Data are shown on the impact of temperature on early larvae of the Mediterranean mussel Mytilus galloprovincialis. Increasing temperatures (18-20-22 °C) altered larval phenotypes at 48 hpf and affected gene expression from eggs to 24 and 48 hpf, with shell biogenesis related genes among the most affected. The effects of temperature on larval susceptibility to infection were evaluated using Vibrio coralliilyticus, a coral pathogen increasingly associated with bivalve mortalities, whose ecology is affected by global warming. Malformations and mortalities at 48 hpf were observed at higher temperature and vibrio concentrations, with interactive effects. In non-lethal conditions, interactions on gene expression at 24 and 48 hpf were also detected. Although temperature is the main environmental driver affecting M. galloprovincialis early larvae, warming may increase the susceptibility to vibrio infection, with consequences on mussel populations
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
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