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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Mycotoxigenic fungi associated with ear-rots in Zimbabwe: identification and inheritance of resistance in southern and West African maize inbred lines
No full textEnglish: Fumonisin, a mycotoxin produced by Fusarium verticillioides, is an intrinsic constraint in maize (Zea mays L.) that has received a low level of attention in Zimbabwe, despite existence of laws nationally and globally setting acceptable limits. Breeding for resistance to the causal fungus is important for the poor farmers that depend on this crop. A survey was conducted that highlighted the presence of F. verticillioides in 23 national storage facilities in the major maize growing areas of Zimbabwe. The morphological analysis identified 33 fungi in storage with F. verticillioides having the highest incidence among field fungi while Eurotium repens was the highest in storage. Aspergillus flavus was observed at significant levels in Bindura in the maize delivered in the previous year. The Fusarium species identified were confirmed by gene sequencing that clustered the derived isolates among the F. verticillioides sequences in the databases. Such high incidences motivated the study of inheritance of resistance where 12 mid-altitude lines from the Seed Co southern African breeding programme and 12 from IITA central and West Africa were mated in a NCDII. The lines had variable levels of resistance to the causal fungi and aflatoxins. F1 hybrids SC 2/IITA 7, SC 3/IITA 1, SC 3/IITA 10, SC 5/IITA 10 and SC 10/IITA 2 had the lowest F. verticillioides ear rot incidences per se and the lowest fumonisin contamination. Within the best yielding hybrids, tester line IITA 4 contributed most in terms of grain yield as it appeared more frequently in the best hybrids. In the parent trial planted alongside the F1 hybrid trials, tester IITA 4 had the highest yield besides also being one of the four lines classified as resistant to aflatoxins. The GCA effects for grain yield, days to mid pollen, days to mid silk and anthesis to silking interval were significant across all sites. Both GCA and SCA were significant for F. verticillioides ear rots and fumonisins contamination, it therefore can be concluded that additive and non-additive gene effects had a role in conferring resistance to these two traits, with additive gene effects playing a major role in the fumonisins, particularly for the southern African inbred lines. Seed Co inbred lines SC 2, SC 3, SC 4, SC 9, SC 11 and SC 12 had desirable GCA for F. verticillioides ear rot with lines SC 2, SC3 and SC12 also having negative GCA for fumonisins. The IITA tester lines with negative GCA for ear rots and fumonisins were IITA 4, IITA 8, IITA 3, IITA 5, IITA 7, IITA 6 and IITA 1. The inbred lines with the highest GCA for yield were SC 10, SC 5, SC 8 (Seed Co), and testers IITA 4 and IITA 2 (IITA) were identified as lines that can play a significant role in the southern African maize breeding programmes. Besides these lines, several more lines and F1 hybrids with per se low infection levels for ear rot were identified and these lines and hybrids can be used in southern Africa to improve the local gene pool in terms of both reaction to ER causing fungi, fumonisins and agronomic performance. To study genetic diversity 1144 SNP markers were used on the 24 inbred lines. Rogers’ dissimilarity coefficients successfully distinguished the Seed Co and the IITA lines which formed the main groups besides an additional group comprising of a single line. The lines IITA 12 and SC 11 had the highest distance of 0.38. There were some sub-groups with the Seed Co materials forming clusters that were consistent with the pedigree data except for one line (SC 3). The IITA material formed two subgroups that could possibly represent two opposite heterotic groups. High heterosis for grain yield averaging 295% and 225% for the MPH and HPH, respectively, was obtained across sites in two years. Negative MPH and HPH for flowering related traits were observed. The ear rot and fumonisin accumulation had negative MPH and HPH. The correlations between the GD and MPH and HPH were significant, low and negative. There was no significant correlation between the SCA for grain yield and GD while there was significant correlation between GD and mean of grain yield per se. Grain yield mean and grain yield SCA were significantly correlated. SCA for F. verticillioides ear rot and fumonisin was significantly positively correlated with MPH and HPH of the same traits. It can therefore be concluded that good genetic gain can be obtained from the use of exotic germplasm when targeting traits such as resistance to ear rot causing fungi and the fumonisins than yield with exceptional few cases.Afrikaans: Fumonisien, ‘n mikotoksien wat deur Fusarium verticillioides geproduseer word, is ‘n intrinsieke beperking in die mieliebedryf, wat ‘n baie lae vlak van aandag in Zimbabwe geniet, ten spyte van die bestaande nasionale en internasionale wette wat aanvaarbare limiete stel. Teling van weerstand teen die mikotoksien produserende fungi is belangrik vir die arm boere wat afhanklik is van die gewas. ‘n Opname is gedoen wat die teenwoordigheid van F. verticillioides in 23 nasionale storingsfasiliteite in die hoof mielieproduserende streke van Zimbabwe getoon het. Die morfologiese analise het 33 fungi in storing getoon met die hoogste insidensie van F. verticillioides in die veld, en Eurotium repens was die hoogste in storing. Aspergillus flavus is gesien in betekenisvolle vlakke in Bindura in die mielies gelewer in die vorige jaar. Die Fusarium spesies wat geïdentifiseer is, is bevestig met geenvolgordebepaling wat die afgeleide isolate vanaf F. verticillioides gegroepeer het volgens volgordes in die databasisse. Hierdie hoë insidensies het die studie op die oorerwing van weerstand gemotiveer, waar 12 mid-hoogte lyne van die Seed Co suidelike Afrika teelprogramme en 12 van IITA sentrale en Wes Afrika programme gekruis is in ‘n NCDII. Die lyne het variënde vlakke van weerstand teen die veroorsakende fungi en aflatoksiene getoon. F1 basters SC 2/IITA 7, SC 3/IITA 1, SC 3/IITA 10, SC 5/IITA 10 en SC 10/IITA 2 het die laagste F. verticillioides kopvrot insidensie per se en die laagste fumonisien kontaminasie getoon. In die basters met die hoogste opbrengs, het toetser lyn IITA 4 die meeste bygedra in terme van graanopbrengs omdat dit die mees algemene ouer in die beste basters was. In die ouerproewe wat langs die F1 bastersproewe geplant is, het toetser IITA 4 die hoogste opbrengs getoon en dit is ook geïndentifiseer as een van die vier lyne met weerstand teen aflatoksiene. Die GCA effekte vir graanopbrengs, dae tot mid stuifmeel, dae tot mid baard en antese tot baard interval was betekenisvol oor al die omgewings. Beide GCA en SCA was betekenisvol vir Fusarium kopvrot en fumonisien kontaminasie. Daarom kan afgelei word dat additiewe en nie-additiewe geeneffekte ‘n rol gespeel het in weerstand teen hierdie twee eienskappe, met additiewe geeneffekte wat ‘n groot rol gespeel het in die fumonisiene, veral in die suidelike Afrika ingeteelde lyne. Seed Co ingeteelde lyne SC 2, SC 3, SC 4, SC 9, SC 11 en SC 12 het goeie GCA vir Fusarium kopvrot met lyne SC 2, SC3 en SC12 gehad met negatiewe GCA vir fumonisiene. Die IITA toetserlyne met negatiewe GCA vir kopvrot en fumonisiene was IITA 4, IITA 8, IITA 3, IITA 5, IITA 7, IITA 6 en IITA 1. Die ingeteelde lyne met die hoogste GCA vir opbrengs was SC 10, SC 5, SC 8 (Seed Co), en toetsers IITA 4 en IITA 2 (IITA) is geïdentifiseer as lyne wat ‘n belangrike rol kan speel in suidelike Afrika mielieteelprogramme. Afgesien van hierdie lyne, is daar ‘n aantal ander lyne en F1 basters met per se lae infeksievlakke vir kopvrot geïdentifiseer en hierdie lyne en basters kan gebruik word in suidelike Afrika om die plaaslike geenpoel te verbeter in terme van reaksie vir kopvrot veroorsakende fungi, fumonisiene en agronomiese eienskappe. Om die genetiese diversiteit te bepaal is 1144 SNP merkers gebruik om die 24 ingeteelde lyne te karakteriseer. Rogers se koeffisiënt van verskille het die Seed Co en die IITA lyne suksesvol onderskei. Hulle het twee hoofgroepe gevorm afgesien van een lyn wat nog ‘n groep gevorm het. Die lyne IITA 12 en SC 11 het die grootste afstand van 0.38 gehad. Daar was sub-groepe in die Seed Co materiaal wat groepe gevorm het wat ooreengestem het met die stambome, behalwe vir een lyn (SC 3). Die IITA materiaal het twee sub-groepe gevorm wat moontlik twee heterotiese groepe verteenwoordig. Hoë heterose vir graanopbrengs met ‘n gemiddeld van 295% en 225% vir MPH en HPH, onderskeidelik, is gekry oor omgewings en jare. Negatiewe MPH en HPH vir blomverwante eienskappe is gesien. Kopvrot en fumonisien akkumulasie het negatiewe MPH en HPH getoon. Die korrelasies tussen die GD en MPH en HPH was betekenisvol, laag en negatief. Daar was geen betekenisvolle korrelasie tussen die SCA vir graanopbrengs en GD nie, maar daar was betekenisvolle korrelasie tussen GD en gemiddelde graanopbrengs per se. Graanopbrengs gemiddeld en graanopbrengs SCA was betekensivol gekorreleer. SCA vir Fusarium kopvrot en fumonisien was betekenisvol positief gekorreleer met MPH en HPH van die eienskappe. Dit kan dus gesê word dat goeie genetiese vooruitgang gemaak kan word deur die gebruik van eksotiese kiemplasma as daar gekyk word na eienskappe soos weerstand teen kopvrot veroorsakende fungi en die fumonisiene.Seed C
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Relationship of molecular genetic distance of seven quality protein maize (Zea mays L.) inbred lines with specific combining ability and grain yield of hybrids
No full textQuality protein maize (QPM) with the opaque-2 gene has double the amount of the essential amino acids (tryptophan and lysine) as compared to normal endosperm maize but the gene is associated with undesirable agronomic traits. The aim of this study was to generate genetic information for use in developing breeding strategies for QPM in Southern Africa. Specific objectives were: i) to study the combining ability and type of gene action controlling yield in crosses among QPM inbred lines from Mexico and Southern Africa ii) to determine the relationship between combining ability for grain yield of QPM hybrids and molecular genetic distances between the parent inbred lines. Seven QPM inbred lines were crossed in a diallel mating design. The genetic distances between the maize inbred lines was quantified by using 62 simple sequence repeat (SSR) markers. The lines and the derived F1 hybrids were also evaluated for tryptophan and protein content. The F1 hybrids were evaluated in replicated trials at five locations. The quality of QPM inbred lines was variable with hybrids made up of high quality lines exhibiting high quality values. There was significant variation among the hybrids for yield and QPM traits. While both the general combining ability (GCA) and the specific combining ability (SCA) were significant, the GCA effects were found to be more important than SCA for yield in this study. QPM inbred line SC1 from Southern Africa had the highest GCA value and consistently appeared as one of the parents of the best yielding F1 hybrids. Preponderance of GCA effects indicated that additive gene effects were found to be more important in conferring high yield. Cluster analysis of the lines based on the SSR markers revealed five groups that were in conformity with pedigree information. The correlation between genetic similarity (GS) and SCA was not significant, low and negative (-0.035) suggesting low predictive value. As a result, use of SSR as a predictive tool for heterotic grouping in breeding maize hybrids should be confirmed by phenotypic data from the field evaluations
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