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Transmembrane signaling and cytoplasmic signal conversion by dimeric transmembrane helix 2 and a linker domain of the DcuS sensor kinase
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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
Intramolecular signal transduction of the sensor histidine kinase DcuS and the aerobic and anaerobic fumarate proteome in the regulation of the Escherichia coli C4-dicarboxylate metabolism
Full text linkThe aerobic and anaerobic utilization of C4-dicarboxylates in Escherichia coli is regulated by the DcuSR two-component system. Depending on oxygen availability, the transcription of the genes of fumarate respiration or the aerobic transporter DctA are induced. The C4-dicarboxylate transporters DctA and DcuB act as co-regulators of DcuS and convert DcuS to its responsive state in the DcuS-transporter sensor complex. C4-dicarboxylates bound at the periplasmic domain of DcuS and trigger a signal cascade across the membrane, emanating from the sensory PASP domain through TM2, a short Linker and the cytoplasmic PASC domain that results in cytoplasmic autophosphorylation at the C-terminal kinase domain of DcuS. TM2 was already shown to transduce the signal across the membrane via a piston type shift, but the entire mechanism in DcuS transmembrane signaling is unknown.
The structure and dynamics of the domains in DcuS intramolecular signal transduction were investigated by oxidative cysteine cross-linking. This revealed a membrane spanning dimeric continuous helix that is mostly stable in both DcuS signaling states. The continuous helix comprises the C-terminal α6 helix of PASP, TM2, the linker, and the N-terminal α1 helix of PASC and thus connects periplasmic signal input with the cytoplasmic signal output domains. The structural dynamics of selected DcuS residues in the DcuS signal transfer were tested by time-resolved cysteine cross-linking. TM2 was shown to be a rigid homo-dimer confirming the piston-type shift as major transmembrane signaling mechanism by TM2. In contrast, the linker represents a dynamic region in signal transduction. PASC also seems to undergo a restructuring in α1 and β1 upon DcuS activation. Furthermore, time-resolved cysteine crosslinking in the absence of the co-regulator DctA showed that DcuS adopts cross-linking reactivity resembling the fumarate activated state. It seems likely that DctA stabilizes homo-dimerization of the linker and α1 of PASC by direct interaction via the DctA helix 8b and thus converts DcuS in its responsive state in the DcuS-DctA sensor complex.
In addition, the aerobic and anaerobic E. coli fumarate proteome was investigated in a ‘shotgun proteomics’ approach. The transcriptional regulation by DcuSR was displayed in the proteomic results. Upregulation of almost all TCA cycle enzymes, anaplerotic reactions, and gluconeogenesis under aerobic conditions was observed. This regulatory effect can be related to an EIIA-P/EIIA ratio-dependent indirect regulation by cAMP/CRP, but a previously unknown regulation by DcuSR is also possible in some cases. The most abundant category of proteins, which was upregulated by fumarate under anaerobic conditions, can be assigned to chemotaxis and motility.108 Seite
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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