1,721,001 research outputs found
Exosomes as a vehicle for alpha-Synuclein toxic species propagation in alpha±-synucleinopathies
Full text linkalpha-synucleinopathies are a group of neurodegenerative disorders characterized by the presence of abnormally aggregated alpha-synuclein (aS). Recent evidence suggests that the early site of aS aggregation is synapses, where aS seems to play its physiological role. Moreover, aggregated aS is reported to be secreted by cells, suggesting its potential involvement in disease initiation and progression. Considering the nature of neurodegenerative disorders as well as the defined, step-wise spreading of Lewy body pathology in alpha-synucleinopathies, the idea of extracellular aS as a pathogenic prion-like agent is extremely appealing. This research project developed in this frame and it is focused on the propagation of aS toxic species mediated by a particular type of extracellular vesicles, exosomes. To this aim, exosomes containing aS and DOPAL modified aS oligomers were purified by HEK293T cells and we focused on the effect of these vesicles on different cell types. Since, in neurons, exosomes appear to be secreted in a spatially and regulated manner through synapses, we first investigate their effect on primary neuronal culture synapses . Upon incubation, aS containing exosomes and, more significantly, DOPAL-modified aS containing exosomes are delivered to synapses, where they alter proteins amounts, function and neuronal morphology. aS containing exosomes contribute also to neuroinflammation: they mediate increment of IL-1beta cytokine production in mouse immortalized microglia cells. Our results highlight an exosomes-driven toxicity of aS not only to neuronal synapses, but also to microglia, inducing the secretion of IL-1beta. Therefore, aS containing exosomes appear as a vehicle of aS toxicity, which might be interesting not only as a future therapeutic target, but also as a potential biomarker for alpha-synucleinopathies
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
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
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