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Trimethyltin-induced expression of protease-activated receptor-1 in rat microglia
No full textNeuroinflammation is a prominent feature shared by various neurodegenerative
diseases and it is important to identify the signal pathways
that control the initiation, progression and termination of the inflammatory
reaction since a well-regulated inflammatory process is essential
for tissue homeostasis. Protease-activated receptors (PARs) are
cleaved and activated by thrombin and other extracellular proteaseswhich are released during tissue trauma and inflammation. PAR-1 is
the prototypic member of the PAR family and has been shown to be
upregulated in several brain pathologies being expressed by neurons
and glial cells. Our previous results show that PAR-1 expression is
increased in astrocytes both in vivo and in vitro after treatment with
the neurotoxic compound trimethyltin (TMT). Administration of TMT
to the rat results in loss of hippocampal neurons and an ensuing gliosis
without blood-brain barrier compromise. TMT caused pyramidal cell
damage within 3 days and a substantial loss of these neurons by 21
days post dosing. Marked microglial activation and astrogliosis are evident
over the same time period. TMT causes large increase of PAR-1
immunoreactivity in microglia by day 7 while in untreated controls this
receptor is barely detectable. In vitro data show that the administration
of the PAR-1 activating peptides (TRAP6 and TFLLR) inhibits the production
of the pro-inflammatory cytokines TNF-alpha and IL-6 in
microglial cells treated with lipopolysaccharide (LPS) while promoting
the release of the anti-inflammatory cytokine IL-10. Our results suggest
that PAR-1 may be involved in the regulation of the inflammatory
response in the brain
Protease-activated receptor 1 upregulation in rat microglia following trimethyltin treatment: an in vivo and in vitro study
No full text
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
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
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