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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
Xylem lumen: not just a Xylella playground.
No full textXylella outbreak in Puglia is ravaging olive plants and research is trying different paths moving through serious social and practical difficulties. The laboratory of Botany in Lecce, in collaboration with CNR ISPA local section, University of Firenze and University of Neuchatel supports the scientific community effort investigating the Olea europea xylem lumen through microscopic analysis. This apoplastic space is the channel through which the pathogen may be targeted by drugs but also a battleground on which the plant itself deploys its natural defensive barriers. In particular woody plants are able to selectively block the traffic through vessels with an active process known as tylose. It is known that tylose impairs water transport during the development of Pierce's disease (PD), caused by Xylella fastidiosa in grape. The cavitation-induced embolisms of xylem due to the bacterial colonization appears to develop before tyloses (Perez-Donoso et al 2016), anyhow both embolisms and tyloses develop with the same pattern and correlate to symptoms.
Scanning Electron Microscope observations performed in the xylem of olive plants allowed the identification of different forms of xylem defects, from tylose to biotic obstructions and allowed the correct interpretation of vessels obstructions visualized at low magnification by optical microscopy and confocal microscopy.
A visual screening of sections from branches of the three most representative Olea europea cultivars present in the infected area of South Puglia, Cellina di Nardò, Leccino and Ogliarola salentina, was performed. The results will be discussed.
Essential bibliography
Perez-Donoso, A. G., Lenhof, J. J., Pinney, K., Labavitch, J. M. (2016) Vessel embolism and tyloses in early stages of Pierce's disease. AUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH Volume: 22 Issue: 1 Pages: 81-8
Articolazione della risposta al cadmio nelle briofite in relazione alla loro storia evolutiva
No full textDittrichia viscosa selection strategy based on Nip1.1 Gene for Arsenic phytoremediation
No full textArsenic uptake by plants occurs primarily through the root but it is not well known. Dittrichia viscosa
uptake and translocation of As is not fully understood and some data are contradictory. In one study
is reported that As is fully translocated to D. viscosa shoots and volatilized, while in another is show
that As is stabilized in the roots. In a previous work we studied the accumulation of As[III] and As[V],
confirming the high variability among individuals. We established several experimental clonal
populations to perform a functional study on the aquaporin NIP1.1.
D. viscosa is not a hyperaccumulator plant but can grow in high drought conditions while still
producing large biomass, even tolerating significant concentrations of As[III], As[V] and Cd[II]. In
spite of these remarkable characteristics, adaptive modification of performances is not predictable in
wild populations.
Genetic stability is a desirable trait and interest in the genetic improvement of this plant species is
increasing. We test a strategy that take in consideration the use of a clonal population of D. viscosa
with a defined NIP1.1 expression level and the in-vitro micropropagation technique to quickly scaleup the number of plants to perform specific HMs phytoremediation of contaminated areas
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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