1,720,994 research outputs found
Plasma-activated water to foster sustainable agriculture: Evidence and quest for the fundamentals
No full textSocietal Impact Statement: An increasing world population facing limited natural resources poses a global challenge to food security. This challenge is increasing due to climate change, which in turn is strongly affected by the food system that accounts, according to the Food and Agriculture Organization (FAO), for one-third of the global greenhouse gas emissions. To make food production sustainable, a new model of agriculture with responsible use of natural resources and minimum use of agrochemicals must be implemented. This approach fosters the development of new technologies, such as that based on plasma-activated water, whose effects, perspectives, and quest for fundamentals are discussed herein. Summary: Applications based on non-thermal atmospheric plasmas - commonly referred to as cold plasmas - to the food system are emerging as effective technologies that may contribute to reconciling the increasing demand for food with the need to minimize its environmental impact. In particular, the technology based on the so-called plasma-activated water (PAW) has proven effective in promoting plant germination, growth, and resistance to biotic and abiotic stresses. Several interpretations have been proposed for the various beneficial effects played by PAW on plants, and the quest for the fundamental processes underlying them is ongoing. In this contribution, we present and discuss the approach based on calcium signaling, a ubiquitous and versatile signal transduction mode that has recently been demonstrated to be involved in PAW sensing by plants. The plant Ca2+-mediated response is related to the mixture of reactive chemical species, as confirmed by selective plasma irradiation. Directions for future research are discussed, with a special focus on the link between Ca2+ signaling and plant responses to PAW/cold plasma. The potential offered by an interdisciplinary approach, combining real-time monitoring of intracellular Ca2+ changes with machine learning algorithms, is pinpointed
Shaping intracellular calcium signatures associated with environmental stresses by plasma-activated water in Arabidopsis thaliana
No full textNon-thermal plasma technology is gaining increasing attention for numerous applications in agriculture. Water activated by non-thermal plasma discharge has been shown to promote plant growth and alleviate environmental stress, by improving plant tolerance to abiotic stresses and pre-alerting plant defence responses. Calcium is known to play a key role as an intracellular messenger in various plant signal transduction pathways, including sensing of plasma-activated water (PAW). In this work we analysed the effect of plant treatment with PAW on the transient elevations in intracellular Ca2+ levels triggered by the subsequent challenge with different abiotic and biotic stresses. PAW was found to alter the cytosolic Ca2+ signals induced by salinity, drought, and the pathogen-derived peptide elicitor flg22 in Arabidopsis thaliana seedlings that stably express the bioluminescent Ca2+ reporter aequorin in the cytosol. By uncovering stimulus-specific changes in intracellular Ca2+ signatures associated with environmental stresses, the obtained data provide insights into the mechanisms underlying PAW-induced stress tolerance. A mechanistic understanding of PAW effects on plants may allow the fine-tuning of this promising technology and its application for a more sustainable agriculture
Fungal signals and calcium-mediated transduction pathways along the plant defence-symbiosis continuum
Full text linkThis article is an invited Commentary, published in the Special Issue "Mycorrhizal research now", New Phytologist 2024, Volume 242, Issue 4
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
- …
