1,720,975 research outputs found
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
Metabolic priming in G6PDH isoenzyme-replaced tobacco lines improves stress tolerance and seed yields via altering assimilate partitioning
No full textWe investigated the basis for better performance of transgenic Nicotiana tabacum plants with G6PDH-isoenzyme replacement in the cytosol (Xanthi::cP2::cytRNAi, Scharte et al., 2009). After six generations of selfing, infiltration of Phytophthora nicotianae zoospores into source leaves confirmed that defence responses (ROS, callose) are accelerated, showing as fast cell death of the infected tissue. Yet, stress-related hormone profiles resembled susceptible Xanthi and not resistant cultivar SNN, hinting at mainly metabolic adjustments in the transgenic lines. Leaves of non-stressed plants contained twofold elevated fructose-2,6-bisphosphate (F2,6P2) levels, leading to partial sugar retention (soluble sugars, starch) and elevated hexose-to-sucrose ratios, but also more lipids. Above-ground biomass lay in between susceptible Xanthi and resistant SNN, with photo-assimilates preferentially allocated to inflorescences. Seeds were heavier with higher lipid-to-carbohydrate ratios, resulting in increased harvest yields - also under water limitation. Abiotic stress tolerance (salt, drought) was improved during germination, and in floated leaf disks of non-stressed plants. In leaves of salt-watered plants, proline accumulated to higher levels during illumination, concomitant with efficient NADP(H) use and recycling. Non-stressed plants showed enhanced PSII-induction kinetics (upon dark–light transition) with little differences at the stationary phase. Leaf exudates contained 10% less sucrose, similar amino acids, but more fatty acids – especially in the light. Export of specific fatty acids via the phloem may contribute to both, earlier flowering and higher seed yields of the Xanthi-cP2 lines. Apparently, metabolic priming by F2,6P2—combined with sustained NADP(H) turnover—bypasses the genetically fixed growth–defence trade-off, rendering tobacco plants more stress-resilient and productive
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
At MYB41 acts as a dual‐function transcription factor that regulates the formation of lipids in an organ‐ and development‐dependent manner
No full textAbstract
The plant cuticle controls non‐stomatal water loss and can serve as a barrier against biotic agents, whereas the heteropolymer suberin and its associated waxes are deposited constitutively at specific cell wall locations. While several transcription factors controlling cuticle formation have been identified, those involved in the transcriptional regulation of suberin biosynthesis remain poorly characterized. The major goal of this study was to further analyse the function of the R2R3‐Myeloblastosis (MYB) transcription factor
At
MYB41 in formation of the cuticle, suberin, and suberin‐associated waxes throughout plant development.
For functional analysis, the organ‐specific expression pattern of
AtMYB41
was analysed and
Atmyb41
ge
alleles were generated using the CRISPR/Cas9 system. These were investigated for root growth and water permeability upon stress. In addition, the fatty acid, wax, cutin, and suberin monomer composition of different organs was evaluated by gas chromatography.
The characterization of
Atmyb41
ge
mutants revealed that
At
MYB41 negatively regulates the production of cuticular lipids and fatty acid biosynthesis in leaves and seeds, respectively. Remarkably, biochemical analyses indicate that
At
MYB41 also positively regulates the formation of cuticular waxes in stems of
Arabidopsis thaliana
.
Overall, these results suggest that the
At
MYB41 acts as a negative regulator of cuticle and fatty acid biosynthesis in leaves and seeds, respectively, but also as a positive regulator of wax production in
A. thaliana
stems.Deutsche Forschungsgemeinschaft https://doi.org/10.13039/50110000165
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
Arabidopsis GH3 .10 conjugates jasmonates
No full textAbstract Jasmonates regulate plant development and defence. In angiosperms, the canonical bioactive jasmonate is jasmonoyl‐isoleucine (JA‐Ile), which is formed in Arabidopsis thaliana by JAR1 and GH3.10. In contrast to other jasmonate biosynthesis or perception mutants, however, gh3.10 jar1 knockout lines are still fertile. Therefore we investigated whether further jasmonates and GH3 enzymes contribute to regulation of fertility. Jasmonate levels were analysed by liquid chromatography–mass spectrometry. The substrate range of recombinant GH3.10 and related GH3 enzymes was studied using non‐targeted ex vivo metabolomics with flower and leaf extracts of A. thaliana and in vitro enzyme assays. Jasmonate application experiments were performed to study their potential bioactivity. In flowers and wounded leaves of gh3.10 jar1 knockout lines JA‐Ile was below the detection limit. While 12‐hydroxy‐JA was identified as the preferred substrate of GH3.10, no other recombinant GH3 enzymes tested were capable of JA‐Ile formation. Additional JA conjugates found in wounded leaves (JA‐Gln) or formed in flowers upon MeJA treatment in the absence of JA‐Ile (JA‐Gln, JA‐Asn, JA‐Glu) were identified. The aos gh3.10 jar1 was introduced as a novel tool to test for the bioactivity of JA‐Gln to regulate fertility. This study found JAR1 and GH3.10 are the only contributors to JA‐Ile biosynthesis in Arabidopsis and identified a number of JA conjugates as potential bioactive jasmonates acting in the absence of JA‐Ile. However, their contribution in regulating fertility is yet to be conclusively determined.Deutsche Forschungsgemeinschaft https://doi.org/10.13039/50110000165
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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