1,721,003 research outputs found
Evaluating the survival and environmental fate of the biocontrol agent Trichoderma atroviride SC1 in vineyards in northern Italy
No full textTo study the survival in the soil and the dispersion in the environment of Trichoderma atroviride SC1 after soil applications in a vineyard. METHODS AND RESULTS: Trichoderma atroviride SC1 was introduced into soil in two consecutive years. The levels of T. atroviride populations at different spatial and temporal points following inoculation were assessed by counting the colony-forming units and by a specific quantitative real-time PCR. A high concentration of T. atroviride SC1 was still observed at the 18th week after inoculation. The vertical migration of the fungus to a soil depth of 0.4 m was already noticeable during the first week after inoculation. The fungus spread up to 4 m (horizontally) from the point of inoculation and its concentration decreased with the increasing distance (horizontal and vertical). It was able to colonize the rhizosphere and was also found on grapevine leaves. One year after soil inoculation, T. atroviride SC1 could still be recovered in the treated areas. CONCLUSIONS: Trichoderma atroviride SC1 survived and dispersed becoming an integrant part of the local microbial community under the tested conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: The persistence and rapid spread of T. atroviride SC1 represent good qualities for its future use as biocontrol agent against soilborne pathogens
Impact of the biocontrol agent Trichoderma atroviride Sc1 on soil microbial communities of a vineyard in Northern Italy
No full textThe fungus Trichoderma atroviride SC1 is an experimental biocontrol agent (BCA) that is active against the fungus Armillaria mellea. Following the application of Trichoderma to the surface soil of a vineyard, we used a highly specific real-time PCR, previously validated for the analysis of soil microcosms, to monitor the populations of this fungus at different soil depths over several months. The quantification obtained using this molecular method was highly correlated with laboratory assays of colony-forming units. The native communities of bacteria and fungi in the soil were analyzed using automated ribosomal intergenic spacer analysis (ARISA), and transient changes were observed following the application of T. atroviride SC1 conidia. A principal component of variance analysis demonstrated that the introduction of T. atroviride SC1 had an effect on the soil microflora during the first two weeks following inoculation. However, at later dates, environmental conditions had a higher influence on the surveyed communities than the BCA application, as confirmed through the use of the Shannon index of biodiversity. Soil depth had a strong influence on the composition and biodiversity of fungal communities. © 2009 Elsevier Ltd. All rights reserved
Real-time PCR for detection and quantification of the biocontrol agent Trichoderma atroviride strain SC1 in soil
No full textTrichoderma (Hypocreales, Ascomycota) is a widespread genus in nature and several Trichoderma species are used in industrial processes and as biocontrol agents against crop diseases. It is very important that the persistence and spread of microorganisms released on purpose into the environment are accurately monitored. Real-time PCR methods for genus/species/strain identification of microorganisms are currently being developed to overcome the difficulties of classical microbiological and enzymatic methods for monitoring these populations. The aim of the present study was to develop and validate a specific real-time PCR-based method for detecting Trichoderma atroviride SC1 in soil. We developed a primer and TaqMan probe set constructed on base mutations in an endochitinase gene. This tool is highly specific for the detection and quantification of the SC1 strain. The limits of detection and quantification calculated from the relative standard deviation were 6000 and 20,000 haploid genome copies per gram of soil. Together with the low throughput time associated with this procedure, which allows the evaluation of many soil samples within a short time period, these results suggest that this method could be successfully used to trace the fate of T. atroviride SC1 applied as an open-field biocontrol agent. © 2008 Elsevier B.V. All rights reserved
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
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