1,721,067 research outputs found
Effect of Genetic Divergence of<i>Striga hermonthica</i>(Delile) Benth.-Resistant Maize Inbred Lines on Heterosis and Hybrid Performance under Parasite Pressure
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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
SELECTION FOR GRAIN YIELD IN SORGHUM UNDER MOISTURE AND NUTRIENT STRESS ENVIRONMENTS
No full textCrop breeders in the semi-arid tropics often confront a combination of
moisture and nutrient stress in their target production environments.
Stability of performance under stress conditions is, thus, a desirable
goal for crop improvement. The objectives of these studies were (1) to
explore the extent of genetic variability among recombinant inbred
lines of sorghum (Sorghum bicolor ) in high and low fertility
as well as in irrigated and rainfed conditions, and (2) to predict and
measure the correlated responses of sorghum yields when selection is
exercised in either one environment or a combination of contrasting
environments. We evaluated 57 unselected recombinant inbred (RI)
sorghum lines. Large differences in yield, height, and maturity were
detected among lines in each contrasting environment. Genetic variance
and heritability estimates for each trait in each stress environment
did not differ significantly from those in the corresponding non-stress
environments. For improving yield under stress, indirect selection in
high fertility or in the irrigated environment was less efficient than
direct selection in the corresponding stress environment (low fertility
or rainfed). When indirect selection involved yield combinations from
low and high fertility or rainfed and irrigated conditions, at least
five lines appeared among the 10 top-ranking lines of each contrasting
environment. Thus, greater gain in performance over contrasting
environments may be achieved by selecting for yield in more than one
environment, rather than by selecting in any single environment
Selection for Grain Yield in Sorghum Under Moisture and Nutrient Stress Environments
No full textCrop breeders in the semi-arid tropics often confront a combination of moisture and nutrient stress in their target production environments. Stability of performance under stress conditions is, thus, a desirable goal for crop improvement. The objectives of these studies were (1) to explore the extent of genetic variability among recombinant inbred lines of sorghum (Sorghum bicolor) in high and low fertility as well as in irrigated and rainfed conditions, and (2) to predict and measure the correlated responses of sorghum yields when selection is exercised in either one environment or a combination of contrasting environments. We evaluated 57 unselected recombinant inbred (RI) sorghum lines. Large differences in yield, height, and maturity were detected among lines in each contrasting environment. Genetic variance and heritability estimates for each trait in each stress environment did not differ significantly from those in the corresponding non-stress environments. For improving yield under stress, indirect selection in high fertility or in the irrigated environment was less efficient than direct selection in the corresponding stress environment (low fertility or rainfed). When indirect selection involved yield combinations from low and high fertility or rainfed and irrigated conditions, at least five lines appeared among the 10 top-ranking lines of each contrasting environment. Thus, greater gain in performance over contrasting environments may be achieved by selecting for yield in more than one environment, rather than by selecting in any single environment.
Key Words: Crop improvement, genetic variance, heritability, irrigated, rainfed
Résumé
Les reproductions de plante dans les tropiques semi-arides sont souvent confrontés à la combinaison de l'humidité et au stress des substances nutritives dans leurs environnements de productions visés. La stabilité de performance sous des conditions de stress est, ainsi, un objetif désirable pour l'amélioration de plante. Les objectifs de ces études étaient (1) d'explorer l'étendue de la variabilité génetique entre les races consanguines des recombinants de sorgho (Sorghum bicolor) en forte et faible fertilité ainsi que dans des conditions d'irrigation et pluies, et (2) prédire et mesurer les réponses corrélées des rendements de sorgho quand la sélection est exercée dans un seul environnement ou une combinaison contrastée d'environnements. Nous avons évalué 57 lignes consanguines des recombinants de sorgho non sélectionnées (RI). Des larges différences en rendement, hauteur et maturité étaient detectées entre les races dans chaque environnement contrasté. La variance génetique et les prévisions d'héritage pour chaque trait et chaque stress d'environnment n'ont pas différé de manière significative des correspondants en environnments non stressés. Pour améliorer le rendement sous stress, la sélection indirecte en haute fertilité ou en environnemnt irrigué étaient moins efficace que les sélection directe en environnement correspondant stressé (faible fertilité ou pluie). Quand la sélection indirecte a impliqué des combinaisons de rendements de faible et fertilité élevée ou conditions pluvieuses et irriguées, au moins cinq races ont apparu pami les 10 premiers classements des races de chaque environnement contrasté. Ainsi, un grand gain en performance au-délà des environnements contrastés peut- être atteint par sélection pour rendement dans plus d'un environnement, plutot que par sélection dans n'importe un seul environnement.
Mots Clés: Amélioration de la plante, variance génetique, en héritage, irriué, pluvieux
(Af Crop Sci J 2003 Vol 11 No 2 pp55-64
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
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