1,723,143 research outputs found
Analysis of the role of mitochondrial morphology in autophagy
Full text linkPARK2 gene encodes for an E3 ubiquitin ligase called Parkin. Loss-of-function mutations in this gene cause early onset of Parkinson’s disease, a neurodegenerative disorder of unknown etiology. The role of Parkin in neuron maintenance is still unknown, however it has been linked to the regulation of mitochondria dynamic. Recent works show that Parkin is selectively recruited to dysfunctional mitochondria, where it mediates their elimination via autophagy. Parkin translocation and Parkin-mediated autophagy depend on the Serine/Threonine-protein kinase PINK1 (PTEN-induced putative kinase 1), which is selectively stabilized on dysfunctional mitochondria where it recruits Parkin. However, it remains unknown which cellular signals or covalent modifications directly regulate Parkin translocation.
Confocal microscopy of EYFP-Parkin transfected MEFs shows that Parkin has a cytoplasmic localization. After treatment with the mitochondrial uncoupling agent Carbonyl cyanide m-chlorophenyl hydrazine (CCCP), Parkin appears as spots that co-localize with mitochondria. We found that pretreatment with the Ca2+ selective chelator BAPTA completely blocked Parkin translocation. We also found that inhibition of Ca2+ dependent phosphatase Calcineurin A (CnA) impaired Parkin recruitment and that CaN constitutive active expression was able to induce Parkin translocation per se, independently from PINK1. In accordance to the in vitro data, we showed that in the Drosophila fruit fly, Calcineurin constitutive active expression is able to rescue the climbing ability of a PINK1 in vivo model of Parkinson’s Disease
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
Olfactory learning in a parasitic wasp
No full textIn numerous past studies, parasitic hymenoptera species have demonstrated sophisticated learning abilities particularly when associating chemical odours with a reward (e.g. Lewis and Takasu, 1990; Turlings et al., 1993a). This type oflearning is termed associative learning and can be defined as "The process by which animals learn about casual relationships between events and behave appropriately as a result" (Dickinson, 1980). The parasitic wasp Cotesia plutellae is part of a tritrophic system in which it utilises chemical cues from the food plant of its host, Plutella xylostella, in order to locate this host more effectively. This study investigates how behaviour changes as a response to the learning of these volatile chemicals. Initial experiments determine whether learning of chemical odours from the Chinese cabbage occurs and how learning modifies preference for a particular odour. The study then focuses on which particular chemicals in the profile are important for learning and whether chemicals outside the insect's natural foraging range can be learnt. The results suggest that learning does occur in this species and that actively released plant volatiles playa particularly important in role. The sesquiterpene (E)-B-caryophyllene may be a key component in learning, although it is likely that a combination of chemicals are more effective. Cotesia plutellae appears to learn a novel chemical vanillin, which does not normally occur in its foraging range. Bioassays showed that as well as spending more time in the appropriate odour field, experienced parasitoids may decrease their velocity and increase meander. Applications of this research are discussed.</p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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