1,720,980 research outputs found
Salicylic acid enhances the synthesis of TobaccoNecrosis Virus (TNV) and inhibits formation of antiviral factors in Chenopodium amaranticolorplants
No full textSalicylic acid (SA) is often regarded as a signal molecule involved in systemic acquired resistance (SAR) against plant virus infections. When infiltrated into Chenopodium amaranticolor leaves 12 h prior to inoculation with tobacco necrosis virus (TNV), it caused an increase in virus synthesis. It seems therefore, that in our system, SA is involved in a mechanism of acquired susceptibility rather than acquired resistance to TNV. These results are different from all others previously reported for virus infection and question the proposed SA general role of signal molecule triggering plant defence mechanism against pathogens. Our is not the first evidence of SA-suppressed resistance in plants. This together with previous researches where SA neither induced PR-protein formation nor induced acquired resistance to virus infections, support the idea that plant SAR is a complex phenomenon, probably depending on various mechanisms. One of them is the impaired formation of antiviral factors in the interaction system C. amaranticolor/TNV
Inhibition of tobacco necrosis virus (TNV) and potatovirus X (PVX) replication in plants by human interferon
No full textHuman interferon treatments, carried out right after virus inoculation caused in both cases (TNV in Chenopodium amaranticolor, PVX in Gomphrena globosa) a remarkable reduction of virus synthesis in plants. The possibly produced antiviral-active oligoadenylates were recovered
Use of the polymerase chain reaction to clone the potato leafroll virus coat protein gene directly from the total RNA of infected plants
No full textThe potato leafroll virus (PLRV) coat protein (CP) gene was directly cloned from the total RNA extracted from virus-infected plants. First strand cDNA synthesis was not necessarily specific; it was equally efficient using either random or CP-specific primers. The viral sequence encoding the coat protein was specifically amplified from the total population of cDNA molecules by polymerase chain reaction (PCR), using specific primers bordering the CP gene. The unique amplified product thus obtained was cloned blunt-end into the pT7T318U plasmid vector, and the authenticity of the cloned gene verified by sequence analysis. This cloning strategy obviates the need for virus purification. Sequence comparison of the CP gene of the Italian isolate and those of five other PLRV isolates revealed a close similarity to the three European and the Canadian isolates, and a more distant relationship with the Australian one. © 1995 Kluwer Academic Publishers
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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