1,720,963 research outputs found
ENVIRONMENTALLY SUSTAINABLE TOOLS FOR GRAPEVINE PROTECTION AGAINST FUNGAL AND OOMYCETES DISEASES Activity of peptaibol analogs and a grape chitinase against the grape pathogens B. cinerea and P. viticola
Full text linkGrapevine productions is worldwide affected by fungal pathogens both in the field and during post-harvest storage. In addition to yield losses, even the quality of grape and wine is affected.
The management of these pathogens mainly relies on chemicals and agronomical practices. The majority of the plant protection products (PPPs) distributed in the vineyard are directed to control Botrytis cinerea and Plasmopara viticola, causal agents of gray mold and downy mildew disease, respectively. However, pathogens can develop resistance to synthetic fungicides. Moreover, the high use of PPPs poses serious risks to the environment and the health of operators and consumers. In this regard, European Union (UE) policies foresee a 50% reduction in the use of chemical pesticides by 2030 and the implementation of integrated approaches for crop protection.
The research studies presented in this thesis share the final purpose to find out new alternative strategies and molecules to counteract grapevine pathogens. To this aim, a deep knowledge of the pathogenic mechanism is fundamental. Therefore, in the first part of the thesis the interaction between B. cinerea and grapevine was investigated by characterizing the ability of this fungus to detoxify plant defense proteins. During ripening, grape berries accumulate a class IV chitinase, a pathogenesis related (PR) protein with antifungal activity. However, the protease activity of B. cinerea is able to cleave this chitinase impairing its antifungal activity. This research could represent a first step into the identification of new fungal virulence factors to be counteracted.
The second part of the thesis focused on the development of new biopesticides active against P. viticola and B. cinerea. The effectiveness of several water-soluble analogs produced by targeted amino acid substitutions of an antimicrobial peptide (peptaibol) naturally produced by Trichoderma longibrachiatum, was evaluated against the two pathogens. The assays allowed to identify a peptide highly effective against both pathogens that may be developed as biopesticide.Grapevine productions is worldwide affected by fungal pathogens both in the field and during post-harvest storage. In addition to yield losses, even the quality of grape and wine is affected.
The management of these pathogens mainly relies on chemicals and agronomical practices. The majority of the plant protection products (PPPs) distributed in the vineyard are directed to control Botrytis cinerea and Plasmopara viticola, causal agents of gray mold and downy mildew disease, respectively. However, pathogens can develop resistance to synthetic fungicides. Moreover, the high use of PPPs poses serious risks to the environment and the health of operators and consumers. In this regard, European Union (UE) policies foresee a 50% reduction in the use of chemical pesticides by 2030 and the implementation of integrated approaches for crop protection.
The research studies presented in this thesis share the final purpose to find out new alternative strategies and molecules to counteract grapevine pathogens. To this aim, a deep knowledge of the pathogenic mechanism is fundamental. Therefore, in the first part of the thesis the interaction between B. cinerea and grapevine was investigated by characterizing the ability of this fungus to detoxify plant defense proteins. During ripening, grape berries accumulate a class IV chitinase, a pathogenesis related (PR) protein with antifungal activity. However, the protease activity of B. cinerea is able to cleave this chitinase impairing its antifungal activity. This research could represent a first step into the identification of new fungal virulence factors to be counteracted.
The second part of the thesis focused on the development of new biopesticides active against P. viticola and B. cinerea. The effectiveness of several water-soluble analogs produced by targeted amino acid substitutions of an antimicrobial peptide (peptaibol) naturally produced by Trichoderma longibrachiatum, was evaluated against the two pathogens. The assays allowed to identify a peptide highly effective against both pathogens that may be developed as biopesticide
Drought, Waterlogging and Co‐Infection Influence the Severity of Coniella granati and Phytophthora palmivora in Pomegranate and the Biocontrol Efficacy of Bacillus amyloliquefaciens
Full text linkCultivation of pomegranate (Punica granatum) is threatened by the emerging pathogens Coniella granati and Phytophthora palmivora. Whether these microorganisms increase their damage due to simultaneous infection and abiotic stress in pomegranate is unknown. Amylo-X LC is an effective biofungicide based on Bacillus amyloliquefaciens but its efficacy to protect pomegranate from C. granati and P. palmivora if plants are under abiotic stress has not been tested. Therefore, the effects of drought, waterlogging and co-infection on the aggressiveness of these two pathogens and the efficacy of Amylo-X LC were evaluated. Pomegranate trees were subjected to regular watering, drought and waterlogging conditions, treated with Amylo-X LC, and individually or simultaneously inoculated in the stem by C. granati and P. palmivora. Drought experienced by trees limited P. palmivora, while waterlogging favoured C. granati. In combined infections, the presence of P. palmivora amplified the damage caused by C. granati in trees subjected to regular watering and drought. Amylo-X LC proved effective in preventing P. palmivora damage and did not allow the synergistic effect of P. palmivora on C. granati to occur in trees under regular watering and drought. Drought further reduced P. palmivora lesions in plants pretreated with Amylo-X LC compared to those under regular watering. The impact of abiotic stress in pomegranate during C. granati and P. palmivora infections and the efficacy of B. amyloliquefaciens as a potential agent against pomegranate dieback were discussed. We conclude that further efforts to evaluate the efficacy of biological control agents on crops exposed to different environmental scenarios are needed
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
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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