1,721,144 research outputs found
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
Molecular, morphological and yield variation among and within populations of globe artichoke, cv "Spinoso sardo"
No full textThe aim of this study was to measure molecular variation, using RAPD, as
well as checking morphological and yield variation of artichoke heads in five
populations of ‘Spinoso sardo’, the most widely grown and economically important
cultivar in Sardinia (Italy). Considerable variation was observed for most of the
morphological and yield characters studied. Analysis of molecular data showed
significant dissimilarities between population. High level of variation within
population was also detected, possibly as a consequence of the multiclonal
composition of the populations but might also be due to mutations occurring over
time (chromosomal aberrations, aneuploidy, polyploidy etc) which have been
selected and vegetatively propagated together with non-variant plants.
Our results show the need to apply clonal selection to narrow the broad
genetic variability within the cultivar and provide uniform and selected material to
farmers. They in turn provide useful information for the definition of the cultivar
ideotype and address important questions on the most suitable strategies for
germplasm preservation and cultivar fingerprinting
Segregation distortion and linkage analysis in eggplant (Solanum melongena L.)
No full textAn anther-derived doubled haploid (DH) and an F2 mapping population were developed from an intraspecific hybrid between the eggplant breeding lines ‘305E40’ and ‘67/3’. The former incorporates an introgressed segment from S. aethiopicum gr. gilo carrying the Rfo-sa1 gene which confers resistance to Fusarium oxysporum; the latter is a selection from an intraspecific cross involving two conventional eggplant varieties and lacks Rfo-sa1.
Initially, 28 AFLP primer combination (PCs) were applied to a sample of 93 F2 individuals and 93 DH individuals, from which 170 polymorphic AFLP fragments were identified. In the DH population, the segregation of 117 of these AFLPs, as well as that of markers closely linked to Rfo-sa1 were substantially distorted, while in the F2 population, segregation distortion was restricted to just ten markers, thus the latter was chosen for map development.
A set of 141 F2 individuals was genotyped with 73 AFLP PCs (generating 406 informative markers), 32 SSRs, four tomato RFLPs and three CAPS markers linked to Rfo-sa1. This resulted in the assigning of 348 markers to 12 major linkage groups. The framework map covered 718.7 cM, comprising 238 markers (212 AFLPs, 22 SSRs, one RFLP and the Rfo-sa1 CAPS).
Marker order and inter-marker distances in this eggplant map were largely consistent with those reported in a recently published SSR-based map. From an eggplant breeding perspective, DH populations produced by anther culture appear to be subject to massive segregation distortion, and thus may not be very efficient in capturing the full range of genetic variation present in the parental lines
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
RAPD variation within and amog populations of globe artichoke cultivar "Spinoso sardo"
No full textGlobe artichoke is a vegetable native to the Mediterranean basin. Its commercial production is mainly based on perennial cultivation of vegetatively propagated clones, which are highly heterozygous and segregate widely when progeny-tested. The aim of this study was to measure genetic variation using random amplified polymorphic DNA (RAPD) in five populations of 'Spinoso sardo', the must widely grown and economically important cultivar in Sardinia (Italy). Analysis ol molecular variance (AMOVA) gave highly significant differences between populations (28.1% of the total genetic diversity); substantial within-population variation was detected (71.8% of total genetic: diversity). The RAPD results show the need to apply clonal selection to narrow the broad genetic variability within the cultivar and to address important questions on the most suitable strategies for germplasm preservation
Molecular, morphological and yield variation among and within populations of globe artichoke, cv "Spinoso sardo”
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