1,721,017 research outputs found
Identification of toxigenic fungal species associated with maize ear rot: Calmodulin as single informative gene
No full textAccurate identification of fungi occurring on agrofood products is the key aspect of any prevention and pest management program, offering valuable information in leading crop health and food safety. Fungal species misidentification can dramatically impact biodiversity assessment, ecological studies, management decisions, and, concerning toxigenic fungi, health risk assessment, since they can produce a wide range of toxic secondary metabolites, referred to as mycotoxins. Since each toxigenic fungal species can have its own mycotoxin profile, a correct species identification, hereby attempted with universal DNA barcoding approach, could have a key role in mycotoxins prevention strategies. Currently, identification of single marker for species resolution in fungi has not been achieved and the analysis of multiple genes is used, with the advantage of an accurate species identification and disadvantage of difficult setting up of PCR-based diagnostic assays. In the present paper, we describe our strategy to set up a DNA-based species identification of fungal species associated with maize ear rot, combining DNA barcoding approach and species-specific primers design for PCR based assays. We have (i) investigated the appropriate molecular marker for species identification, limited to mycobiota possibly occurring on maize, identifying calmodulin gene as single taxonomically informative entity; (ii) designed 17 sets of primers for rapid identification of 14 Fusarium, 10 Aspergillus, 2 Penicillium, and 2 Talaromyces species or species groups, and finally (iii) tested specificity of the 17 set of primers, in combination with 3 additional sets previously developed
Marcatori molecolari per la tracciabilità del cardoncello (Pleurotus eryngii var. eryngii)
No full textIn this work the authors analyzed sixty italian strains of the edible mushroom “cardoncello” (Pleurotus eryngii) belonging to the varieties eryngii and ferulae by sequencing two housekeeping genes (ef1-a and rpb2) and evaluating the activity of peroxidase, superoxide dis- mutase and catalase, in order to find some molecular markers for the traceability of “cardoncello”. Sequence analysis showed the presence of Snps variety-specific (eryngii and ferulae) in both genes useful for the development of molecular identification tools. none correlation between enzymatic analysis and analyzed varieties was observed
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
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