1,720,957 research outputs found
Adenosine-mediated modulation of the embryonic isoform of the muscle nicotinic acetylcholine receptor
No full textAdenosine receptors (ARs) are classified into different subtypes (A1, A2A, A2B and A3Rs) and are expressed in neurons and skeletal muscles. In central nervous system adenosine acts as neuromodulator but its effect in skeletal muscle is still unclear. Here we investigated the possible interplay between ARs and embryonic nicotinic acetylcholine receptor (nAChR) expressed in denervated as well as in developing skeletal muscles.
Electrophysiological experiments were performed in oocytes injected with denervated skeletal muscle membranes and in differentiating mouse myotubes grown in vitro. The nACh-currents were recorded before and after adding the AR agonist NECA (100 μM) or the antagonist CGS15943 (100 nM).
In injected oocytes, we observed that the activation of ARs reduced the nACh-current rundown and slowed the nACh-current decay, while the AR inhibition elicited the opposite effect.
In developing myotubes, recordings of single nAChR channel activity in cell-attached configuration revealed that NECA significantly increased the mean open time while CGS15943 reduced it; both agents did not affect the ion channel conductance. In parallel, Ca2+ imaging experiments showed that NECA increased and CGS15943 blocked the [Ca2+]i spiking activity sustained by the autocrine activation of the nAChRs.
Our preliminary data indicate a modulatory effect mediated by activation of ARs on the embryonic nAChR channels, expressed by denervated and developing skeletal muscles. We hypothesize a potential novel role for ARs in the regulation of AChR-mediated events during skeletal muscle differentiation/regeneration
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
Non-synaptic roles of acetylcholinesterase and agrin.
No full textProteins in living organisms have names that are
usually derived from their function in the biochemical system
their discoverer was investigating. Typical examples are acetylcholinesterase
and agrin; however, for both of these, various
other functions that are not related to the cholinergic system
have been revealed. Our investigations have been focused on
the alternative roles of acetylcholinesterase and agrin in the
processes of muscle development and regeneration. Previously,
we described a role for agrin in the development of excitability
in muscle contraction. In this study, we report the effects of
agrin on secretion of interleukin 6 in developing humanmuscle.
At the myoblast stage, agrin increases interleukin 6 secretion.
This effect seems to be general as it was observed in all of the
cell models analysed (human,mouse, cell lines). After fusion of
myoblasts into myotubes, the effects of agrin are no longer
evident, although agrin has further effects at the innervation
stage, at least in in vitro innervated human muscle. These
effects of agrin are another demonstration of its non-synaptic
roles that are apparently developmental-stage specific. Our data
support the view that acetylcholinesterase and agrin participate
in various processes during development of skeletal muscle
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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