1,720,966 research outputs found
Metabolomics and Transcriptomics: novel approaches to understand resistance in grape against Plasmopara viticola
Get PDFThe grapevine is the most economically important fruit crop worldwide. Among the species of fungi considered to be the main grapevine pathogens, downy mildew is considered to be an extremely destructive disease of the grapevine, caused by the oomycete Plasmopara viticola (Berk. et Curt.) Berl. et de Toni. Grapevine research is directed towards better understanding of plant defence mechanisms and characterisation of the particular plant-pathogen interactions affecting the species. One of the most promising future strategies to ensure plant protection against disease is to stop the use of chemical compounds and focus on the selection of varieties showing durable specific resistance. Understanding plant-pathogen interaction is important for the future of the breeding; indeed grapevine species can be crosses, including resistant traits using conventional breeding techniques. In the last few years, comprehensive studies called omics have been applied to model plant study and these have contributed enormously to plant science. The project aims to decipher the mechanisms responsible for resistance in vine plants, since the molecular bases of the defence mechanism against P. viticola are still poorly understood. In particular, early responses to the pathogen, occurring within the initial 96 hours post inoculation, have been investigated in grape varieties using metabolomic and transcriptomic data. The use of leaf discs is widely adopted in experiments regarding the effect of different types of biotic stress on the biochemical response of the grapevine. Since there is little knowledge regarding mechanical wounding of grapevine leaves, we analyzed changes in phenolic, lipid and carotenoid content in Bianca grapevine leaves subjected to mechanical wounding (leaf discs), testing two different sizes of leaf discs (1.1 cm and 2.8 cm in diameter). One of the most well-known defence responses in vine plants is the production of defence compounds, mainly secondary metabolites also known as phytoalexins. Primary metabolism is also involved in plant defense with the participation of different molecules including carbohydrates, organic acids, amines, amino acids and lipids not only as a source of energy but also as a source of signaling molecules to directly or indirectly trigger defense response. We developed a rapid and versatile method for the extraction, identification and quantification of different classes of grape lipids using liquid chromatographic tandem mass spectrometry (LC-MS/MS). We also validated a method for the identification and quantification of primary compounds belonging to different chemical classes: acids, amminoacids, amines/others and sugars using a GC-MS method of separation and identification, interesting in terms of elucidating the role of primary compounds in plant-microbe interaction in future work. In this project the primary and secondary metabolism were investigated after P. viticola infection, in Bianca grapevine leaves with the aim of covering all the most important classes of plant metabolites. Our results gave a picture of plant metabolome perturbation. Several molecules were altered in Bianca leaf discs compared to the control after P. viticola infection, and they could act as potential biomarkers in Bianca variety after infection with P. viticola. Since plant resistance and plant-pathogen interaction are complex biological processes involving many signalling pathways, the multi omic approach is most suitable for examining these traits. An integrated metabolomic and transcriptomic approach was also applied to correlate variation in gene expression and metabolic perturbation in resistant Jasmine grapevine leaves, with the aim of discovering a specific and early stage biomarkers related to Downy mildew resistance
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
CARATTERIZZAZIONE DELLA COMPONENTE VOLATILE, ZUCCHERINA E POLIFENOLICA DI VARIETÀ DI MELE (MALUS DOMESTICA) COLTIVATE IN ALTO ADIGE
No full textL’analisi della mela risulta essere di notevole importanza sia dal punto di vista nutrizionale, sia sensoriale in termini del profilo aromatico. L’Alto Adige è una provincia in cui la coltivazione di mela rappresenta cultura e tradizione. Proprio per questo l’analisi strumentale quali-quantitativa della composizione delle diverse varietà di mela coltivate in Alto Adige costituisce un importante strumento per una maggiore caratterizzazione e comprensione del prodotto, sia in termini di qualità intrinseca del prodotto stesso, sia in termini di differenziazione tra le diverse varietà commercializzate.
I metodi analitici utilizzati nel presente studio sono la gascromatografia accoppiata a spettrometria di massa (GC-MS) per la determinazione dei composti organici volatili (VOCs); cromatografia ionica (IC) per la determinazione degli zuccheri singoli e acido malico; cromatografia liquida accoppiata a spettrometria di massa (LC-MS/MS) per la quantificazione dei singoli polifenoli.
Lo scopo è quello di determinare la composizione chimica di mele altoatesine della stessa varietà coltivate ad altitudini diverse, per evidenziare una diversificazione soprattutto nei composti volatili; di studiare varietà nuove di interesse e diversi cloni di una stessa varietà sempre al fine di osservare delle differenze chimiche. Tali differenze potrebbero risultare rilevanti sia dal punto di vista nutrizionale sia chimico-aromatico
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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