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Preliminary studies on partial reduction of Colletotrichum acutatum infection by proteinase inhibitors extarcted from apple skin
No full textColletotrichum acutatum, a fungal pathogen that causes soft rot in fruit, produced protease when grown
on casein or apple cell wall, as revealed by a clear zone around the well filled with C. acutatum medium in
a radial diffusion assay. A protease-inhibiting protein (PI) was also extracted from healthy stored apple,
cultivar Cripps Pink, and its activity was tested in vitro and in vivo against a protease produced by
C. acutatum. In in vitro trials the inhibition rate determined by radial diffusion assay was over 41% after
24 h, while in inoculated fruit the inhibition ranged from 23.5% to 45% after 5 days at 20 C. The protease
inhibitor extracted from healthy apple skin was a heat-denaturable protein since the halo produced by
protein extracted from C. acutatum and added to boiled protein extracted from healthy apple skin tissue
was 338.7 mm2, significantly higher than the halo produced by protein extracted from C. acutatum
diluted with fresh protein extracted from healthy tissue (220.7 mm2). Protein secreted by C. acutatum
grown in induced buffer media was tested by polyacrylamide gel electrophoresis. SDS-PAGE of crude
enzyme extract revealed the presence of various protein bands that could be ascribed by their molecular
mass as putative aspartic proteinase, extracellular alkaline proteinase and serine protease. Genomic
analyses are, however, in progress to identify the proteins involved in Colletotrichum patogenicity. More
investigations are required to identify the nature of the substance responsible for C. acutatum inhibition
in apple and to evaluate the possibility of manipulating the protease inhibitor levels in fruit to reduce soft
rot caused by C. acutatum
Transient transformation meets gene function discovery: the strawberry fruit case
Full text linkBeside the well known nutritional and health benefits, strawberry (Fragaria X ananassa) crop draws increasing attention as plant model system for the Rosaceae family, due to the short generation time, the rapid in vitro regeneration, and to the availability of the genome sequence of F. X ananassa and of the closely related F. vesca species. In the last years, the use of high-throughput sequence technologies provided large amounts of molecular information on the genes possibly related to several biological processes of this crop. Nevertheless, the function of most genes or gene products is still poorly understood and needs investigation. Transient transformation technology provides a powerful tool to study gene function in vivo, avoiding difficult drawbacks that typically affect the stable transformation protocols, such as transformation efficiency, transformants selection and regeneration. In this review we provide an overview of the use of transient expression in the investigation of the function of genes important for strawberry fruit development, defence and nutritional properties. The technical aspects related to an efficient use of this technique are described, and the possible impact and application in strawberry crop improvement are discussed
First Report of Colletotrichum acutatum Causing Bitter Rot on Apple in Italy
No full textItaly could be considered the main apple-producing country in the European Union. Italian apple (Malus domestica L. Borkh.) production is estimated at approximately 2,100 million tons and encompasses a wide range of varieties, harvested from August to November. Colletotrichum acutatum, which causes severe losses to strawberry production, was a regulated organism for all European countries until 2008, when it was removed from the EPPO quarantine pathogen list because of its wide distribution in strawberry production areas. During the growing season of 2010, fungi were isolated from apple fruits exhibiting bitter rot symptoms after four months of storage in several packinghouses in the Emilia Romagna region. The apples belonged to the ‘Golden Delicious’, ‘Granny Smith’, Pink Lady’ and ‘Crisp Pink’ varieties. Lesions on the fruit surface were circular and 1 to 3 cm in diameter. When lesions enlarged, they became sunken with relatively firm rotten tissues. The fungal fruiting structures, acervuli, were distributed sparsely or densely on old lesions, and under humid conditions, they discharged an orange conidial mass. Conidia observed under a light microscope appeared hyaline and fusiform, sized 8 to 16 x 2.5 to 4 μm, with two pointed ends or one rounded end. The fungal isolates were grown on potato dextrose agar (PDA) plates incubated at 25°C
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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