1,721,037 research outputs found
Composti volatili nelle interazioni ecologiche vegetali
No full textLe piante, grazie alla loro grande plasticità biochimica, sono in grado di produrre un’ampia varietà di composti organici volatili (Volatile Organic Compounds, VOCs) con funzione di segnalazione e modulazione delle relazioni ecologiche. Simbionti, competitori, parassiti e patogeni sono in grado di percepire e decifrare questa complessa rete di segnali gassosi.
La comprensione dei meccanismi alla base delle interazioni ecologiche mediate dai VOCs è già stata utilizzata per sviluppare alcuni metodi di coltivazione maggiormente efficaci e sostenibili rispetto ai trattamenti agrochimici standard.
Questa dissertazione prende in esame il ruolo dei VOCs nelle dinamiche ecologiche che interessano le piante. Inoltre, sono riportati possibili ricadute pratiche dello studio dei VOCs in ambito agrario.Due to their biochemical plasticity, plants produce a great variety of volatile organic compounds (VOCs), leading to the evolution of a complex signalling system in their ecosystem. In fact, plant-associated microbes and animals are able to modulate and decipher gaseous environmental cues during their ecological interactions. In addition, volatile byproducts may significantly affect parameters such as humidity and temperature.
Some volatile molecules are signals or mediators of plant defences. Among them, several plant hormones (ethylene, salicylic acid and jasmonic acid derivatives) are crucial for the activation of defence responses, in some cases through the production and release of toxic or deterrent essential oils, alkaloids, terpenoids, sulfur- or cyanide-containing molecules. Other plant-derived volatile signals may result attractant or beneficial for insects and microbes, thus driving host-specific relationships, such as herbivory or symbiosis. Finally, third parties may recognize compounds originating from an existing interactions between plants and other ecological actors to modulate their activity.
This review aims to summarize the main mechanisms underlying volatile signals-mediated interactions between species for the development of environmentally sustainable applications. To date, significant results have been achieved in the control of some pests and pathogens.
This review explores the variety of plant gas emissions and of the ecological relations with microbes and insects mediated by such signals. Finally, some technologies are discussed, which make use of the specific plant emissions in agriculturally relevant applications
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
Promoting Strawberry (<i>Fragaria</i> × <i>ananassa</i>) Stress Resistance, Growth, and Yield Using Native Bacterial Biostimulants
Full text linkStrawberry production is challenged by several abiotic and biotic stresses, such as drought, soil salinity, and the angular leaf spot (ALS) disease caused by Xanthomonas fragariae. In recent decades, the development of commercial products containing combinations of different Plant-Growth-Promoting (PGP) microorganisms has been one of the main focuses of agricultural research. However, their results are often erratic depending on crop species, environmental conditions, and competition among the different strains or indigenous plant microbiota. The use of beneficial microorganisms selected from the crop-specific microbiota may help overcome this limitation, promoting their utilization for sustainable agriculture. The culturable bacteriota of strawberry plants was screened to identify PGP activities in vitro. Bacterial isolates were tested in vivo on strawberry plants in both optimal and stress (X. fragariae infection or salinity) conditions, allowing the selection of strains of Pseudomonas fluorescens, Stenotrophomonas rhizophila, and Agrobacterium rubi whose application showed a significant increase in plant growth and fruit production (up to seven-fold), even under stress conditions, and the ability to control ALS by over 50%. Potential synergistic effects among PGP isolates were tested by coordinated inoculation. However, plant growth and fruit quality were not promoted, except for fruit weight and size, by coordinate inoculation in comparison to m23 and m27 single-strain treatment
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
- …
