1,721,001 research outputs found
Provenance study of Bengal Fan turbidites (IODP Expeditions 353-354) : tectonic and climatic implications - M. Limonta, A. Resentini, E. Garzanti
No full textProvenance study of Bengal Fan turbidites (IODP Expeditions 353-354) : tectonic and climatic implications - M. Limonta, A. Resentini, E. Garzanti</p
ACA12 IS A DEREGULATED ISOFORM OF PLASMA MEMBRANE CA2+-ATPASE OF ARABIDOPSIS THALIANA
Get PDFSeveral environmental and endogenous stimuli activate plant signal transduction pathways through transient increases in cytosolic free calcium concentrations ([Ca2+]cyt). Strong evidence indicates that plant response specificity is triggered by the amplitude, shape, frequency and localization of these stimulus-induced Ca2+ oscillations. Due to their role in Ca2+ efflux from the cytosol, plant auto-inhibited Ca2+-ATPases (ACAs) are involved in restoring the cytosolic basal concentration of Ca2+ after its rise due to stimulus perception, therefore affecting the specificity of plant response to different stimuli. Ten ACA isoforms are present in Arabidopsis thaliana, which are divided into four clusters based on gene structure and sequence homology. Cluster I, II and IV ACAs share a common mechanism of regulation based on a N-terminal auto-inhibitory domain whose action is suppressed by the interaction with the Ca2+-sensor protein calmodulin (CaM). Cluster III isoforms (ACA12 and ACA13) compared to the other ACAs, are almost unknown and show unique features at sequence and expression levels: in particular ACA12 and ACA13 show divergences in residues involved in CaM binding and regulation while the expression levels, normally very low, are increased upon exposure to pathogens or UV stresses.
By confocal microscopy, a GFP-tagged ACA12 (expressed in Arabidopsis plants) was localized at the plasma membrane (PM). ACA12 was then expressed in Saccharomyces cerevisiae strain K616, which lacks endogenous Ca2+ pumps. Our results reveal that ACA12 allows the grow of K616 in a Ca2+-depleted medium, therefore indicating that it is a functional and deregulated Ca2+ transporter. Yeast-expressed ACA12 was then purified by CaM-affinity chromatography and its activity was tested in vitro in order to study its biochemical properties. Biochemical assays results show that ACA12 is a functional Ca2+-ATPase. Moreover, as expected, its activity is not regulated by CaM. Finally, in order to try to explain ACA12 deregulated behaviour, single point mutants of ACA12 were generated and tested for K616 phenotype complementation.
Taken together our results show that ACA12 has unique biochemical features suggesting for it a distinctive physiological role within the ACA family. In particular ACA12 may be involved in Ca2+-dependent signaling pathways in response to plant specific stresses such as pathogens and UV
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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