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Control of the Disease
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Rhizomania
1 January 2016, Pages 175-193
Control of the disease (Book Chapter)
Ratti, C.a , Biancardi, E.b
a Area di Patologia Vegetale, Università di Bologna, Bologna, Italy
b Stazione Sperimentale di Bieticoltura, Rovigo, Italy
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Abstract
This chapter describes the preventative systems adopted for limiting the spread and the damage caused by rhizomania. However, the area affected by the disease is still expanding, notwithstanding the quarantine measures tried in several countries. Since the first observations, the new disease has appeared unusually dangerous for the beet crop, mainly due to the easy spread and the severe effects on sugar yield. When the etiology of rhizomania was discovered, the development of genetic resistances appeared among the few options available against the disease. Because the genetic control is incomplete and it is currently being overcome by new strains of the virus in some areas, new systems of agronomic and biological control are under evaluation for potential integration with the genetic resistances and have shown some evidence of antagonistic ability in depressing the development of Polymyxa betae. A genetically modified strain of Pseudomonas fluorescens was employed for evaluating the possible effect of this organism on lowering the spread of rhizomania. Using some species belonging to the genus Trichoderma, positive results were obtained in the glasshouse. © 2016 Springer International Publishing Switzerland
A Rapid Protocol of Crude RNA/DNA Extraction for RT-qPCR Detection and Quantification
No full textMost of the molecular diagnostic protocols used for phytoplasmas detection are based on the purification of total nucleic acids and on the use of genomic DNA of the pathogen as the target of amplification. Here we describe a diagnostic approach that, avoiding the purification of nucleic acids and exploiting the amplification of the abundant phytoplasma ribosomal RNA molecules produced during the infectious process, allows reducing the time and the costs necessary for the analysis, without affecting sensitivity and specificity. This is useful in particular when high numbers of analyses are required, as in certification programs, to monitor phytoplasmas classified as quarantine or quality pathogens. The protocol here described can be used for the detection and quantification of Candidatus Phytoplasma mali, Ca. P. pyri, Ca. P. prunorum, Ca. P. vitis, and Ca. P. solani by qPCR, RT-qPCR, ddPCR, and ddRT-PCR techniques based on TaqMan chemistry
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
A new PCR based molecular method for early and precise quantification of parasitization in the emerging olive pest Dasineura oleae
No full textBACKGROUND: Dasineura oleae (Angelini 1831) (Diptera: Cecidomyiidae) was considered a minor pest in olive orchards, but in recent years severe outbreaks have been registered in several Mediterranean countries. Damage is caused by the feeding activity of larvae that induce gall formations and alters the physiological activity of the leaves. In Italy, this pest may be controlled by four Hymenoptera parasitoid species belonging to Platygaster and Mesopolobus genera such as Platygaster demades Walker 1835, Platygaster oleae Szelenyi 1940 (Hymenoptera: Platygastridae), Mesopolobus aspilus (Walker 1835) and Mesopolobus mediterraneus (Mayr 1903) (Hymenoptera: Pteromalidae), but parasitization becomes evident only after gall dissection. RESULTS: In this study, we aim to: (i) design a primer for the detection of specimens belonging to Platygaster and Mesopolobus genera; (ii) develop a multiplex quantitative polymerase chain reaction (qPCR) protocol combined to a fast samples DNA extraction method; (iii) apply the developed protocol to field‐collected specimens and compare this method with traditional techniques based on visual estimation of parasitism rate on larvae. Primers were designed to anneal with cytochrome oxidase subunit I (COI) sequences of Platygaster and Mesopolobus genera while protocols were developed to be fast and capable to process several samples at the same time. Molecular analyses demonstrated to provide almost double of the parasitism rate assessed by visual inspection. Furthermore, on second instar larvae the PCR‐based method was able to detect ten‐fold times the parasitization rate estimated by visual inspection. CONCLUSION: The application on a greater scale of this newly developed method could be fundamental in the determination of the biological control potential in olive orchards
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