1,720,963 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
Genetic variability for Russian wheat aphid, Diuraphis noxia resistance in South African wheat genotypes
No full textNear-isogenic genotypes 1684/Tugela and 2199/Tugela containing D. noxia resistance ex SA1684 [PI 137739 (Dn1)] and SA 2199 [PI 262660 (Dn2)] were studied in terms of antibiosis, antixenosis and tolerance, population development of D. noxia under field conditions and the probing behaviour of D. noxia. The susceptible cultivars Betta and Tugela were included for comparison. A sister line of 1684/Tugela, the commercial cultivar TugelaDn, was used to characterise the constitutive and induced components of the resistance to D. noxia. Mechanism of resistance studies showed antibiosis present in both resistant genotypes. No antixenosis was recorded in 2199/Tugela, with only low levels present in 1684/Tugela. 1684/Tugela was able to retain the same leaf area and plant dry mass as 2199/Tugela under a much higher aphid infestation level and both lines were significantly more tolerant than Betta, but did not differ from Tugela. Betta and Tugela showed higher infestation levels, both in terms of percentage tillers infested and number of D. noxia per tiller, and lower yields than the resistant genotypes. The initial rapid increase of D. noxia populations started in the beginning of October and peak aphid numbers were in early to mid- November. EPG data reflecting the probing behaviour of D. noxia revealed distinct differences between the resistant cultivars and the susceptible Betta and Tugela. The influence of resistance in 1684/Tugela and 2199/Tugela on the probing behaviour of D. noxia is different indicating that they contain two different genes, with different modes of action. While resistance in 1684/Tugela was generally reflected by disturbances in phloem activity, the resistance in 2199/Tugela was associated with a high number of short probes denoting some host recognition or epidermal factor involved in the resistance. Constitutive resistance in TugelaDn influenced the time taken by D. noxia to reach sustained phloem feeding. There was no evidence of surface or epidermal factors influencing probing behaviour in this genotype. D. noxia probing on induced resistant TugelaDn was characterised by a reduction in phloem activities on preinfested plants. D. noxia feeding on five day induced resistant plants showed more E2 fractions shorter than ten minutes and fewer E2 fractions longer than 60 minutes indicating a reduction in the ingestion of nutrients. In the case of both constitutive and induced resistance, initiation of phloem ingestion appears easier on susceptible Tugela with a higher number of single phloem salivation periods on the resistant genotype. Yield data for five susceptible and 15 resistant cultivars was analysed quantifying the percentage yield retained under severe infestation. Cultivars with D. noxia resistance from the same donor accession did not react in a similar way, neither was there any indication that they show the same measure of compensation for D. noxia damage. Compensation for aphid infestation was observed in some of the cultivars where higher yields were recorded from some infested cultivars than from cultivars kept aphid free throughout the trial. In the 2000 season, the variation in percentage yield retained between resistant cultivars equalled 63.2%, in the 2001 season 85.0 % and in the 2003 season 41.3%. This study confirms that the interaction between the aphid and each host genotype is unique. The expression of host plant resistance is not only dependent on the donor accession utilised, but also the genetic background in which it is deployed. Furthermore, environmental factors can also significantly influence the performance of host plant resistance to D. noxia.Agricultural Research CouncilWinter Cereal Trus
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Tissue location of resistance in apple to the rosy apple aphid established by electrical penetration graphs
Full text linkA study of the constitutive resistance of the apple cultivar Florina, Malus domestica Borkh. (Rosaceae), to the rosy apple aphid, Dysaphis plantaginea (Passerini) (Homoptera Aphididae), was performed for the first time by the electrical penetration graph (DC-EPG) system, using the susceptible apple cultivar Smoothe as control. All experiments were conducted with apterous adult virginoparae. The results showed a constitutive resistance in Florina due to a much longer period before the first probe reflecting surface factors. Some weak indications were found for pre-phloem resistance and initiating phloem access was not affected as inferred from equal time to show phloem salivation. However, the complete absence of phloem ingestion indicates a major resistance factor in the phloem sieve elements, most likely in the sieve element sap. Surface factors could have affected tissue related variables and this should be studied further. Anyhow, the strong constitutive resistance in Florina, either on the surface alone or in the phloem as well, effectively prevented reliable experiments on induced resistance, previously detected by molecular methods
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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