1,721,058 research outputs found
Root growth of lupins is more sensitive to waterlogging than wheat
No full textIn south-west Australia, winter grown crops such as wheat and lupin often experience transient waterlogging during periods of high rainfall. Wheat is believed to be more tolerant to waterlogging than lupins, but until now no direct comparisons have been made. The effects of waterlogging on root growth and anatomy were compared in wheat (Triticum aestivum L.), narrow-leafed lupin (Lupinus angustifolius L.) and yellow lupin (Lupinus luteus L.) using 1m deep root observation chambers. Seven days of waterlogging stopped root growth in all species, except somenodal root development in wheat. Roots of both lupin species died back progressively from the tips while waterlogged. After draining the chambers, wheat root growth resumed in the apical region at a faster rate than well-drained plants, so that total root length was similar in waterlogged and well-drained plants at the end of the experiment. Root growth in yellow lupin resumed in the basal region, but was insufficient to compensate for root death during waterlogging. Narrow-leafed lupin roots did not recover; they continued to deteriorate. The survival and recovery of roots in response to waterlogging was related to anatomical features that influence internal oxygen deficiency and root hydraulic properties.Helen Bramley, Stephen D. Tyerman, David W. Turner and Neil C. Turne
Regulating Root Aquaporin Function in Response to Changes in Salinity
No full textRapid changes in soil salinity present plants with an osmotic stress. If the concentration of salt in the soil water is too high then water may flow from the plant roots back into the soil. As part of an adaptive response, the regulation of proteins associated with water transport, such as aquaporins, is altered. The change in regulation of aquaporins in roots in response to salt treatments occurs at transcriptional and post‐translational levels. Cell specific changes in aquaporin transcript levels, protein abundance, subcellular localisation, protein phosphorylation, and protein:protein interactions have been observed. It has recently been revealed that a subset of plant aquaporins can function both as water and as ion channels. Both Arabidopsis PIP2;1 and PIP2;2 function as water and ion channels in heterologous systems. AtPIP2;1 and AtPIP2;2 ionic conductance was carried by sodium (Na⁺), indicating that a subset of plant PIP2s could have a role in Na+ transport in plants. We show quantitatively how AtPIP2;1 may account for the calcium (Ca²⁺) and pH sensitive Arabidopsis root non‐selective cation channel. Salt treatments are known to result in a change in AtPIP2;1 phosphorylation, and in Arabidopsis roots this is associated with internalisation of AtPIP2;1 into pre‐vacuolar compartments. Here we review how the regulation of aquaporins, in particular PIP2s, changes in root tissues in response to salt treatments.Samantha A. McGaughey, Jiaen Qiu, Stephen D. Tyerman and Caitlin S. Byr
Cytosolic GABA inhibits anion transport by wheat ALMT1
No full textFirst published: 07 October 2019.
Corrected by: Corrigendum: Cytosolic GABA inhibits transport by wheat ALMT1 (vol 225, pg 671, 2020), in Early view - https://doi.org/10.1111/nph.18214. Since its publication, the authors of Long et al. (2020) have brought to our attention an error in their article. In the Acknowledgements section, the support for the work from the Australian Research Council Centre of Excellence funding to Matthew Gilliham and Stephen Tyerman was incorrectly listed under the number ‘CE14010008’. The correct funding number is ‘CE140100008’, and the corrected Acknowledgements section is shown below. We apologize to our readers for this mistake.Anion transport by Aluminium-activated malate transporter (ALMT) proteins is negatively regulated by gamma-aminobutyric acid (GABA), which increases in concentration during stress. Here, the interaction between GABA and wheat (Triticum aestivum, Ta) TaALMT1 heterologously-expressed in Xenopus laevis oocytes was investigated. GABA inhibited anion transport by TaALMT1 in membrane patches from the cytosolic, not extracellular membrane face, via a reduction in open probability (NPopen ), not an inhibition of channel current magnitude. TaALMT1 currents in patches frequently exhibited rundown with complete removal of cytosolic factors, but were partially sustained by protein kinase C dependent phosphorylation. When applied to whole oocytes a GABA-analogue-BODIPY conjugate inhibited TaALMT1 anion currents from the cytoplasmic face only, whereas free GABA inhibited from both the inside and outside consistent with GABA traversing the TaALMT1 pore then acting from the inside. We propose GABA does not competitively inhibit ALMT conductance through the same pore but rather leads to an allosteric effect, reducing anion channel opening frequency. Across plants GABA is a conserved regulator of anion transport via ALMTs - a family with numerous physiological roles beyond Al3+ tolerance. Our data suggests that a GABA-ALMT interaction from the cytosolic face has the potential to form part of a novel plant signalling pathway.Yu Long, Stephen D. Tyerman, Matthew Gilliha
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
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