1,720,955 research outputs found
Combining ability between drought and heat stress tolerant donors and adapted CIMMYT Zimbabwe maize inbred lines
No full textDrought and heat stress are major abiotic stresses limiting maize production in Zimbabwe and Africa at large. It is of great importance to evaluate the breeding value of combined drought and heat stress donor parents for development of new and locally adapted maize hybrids. A North Carolina Design II (NCDII) mating scheme was used for crossing 10 combined drought and heat stress tolerant donor lines and six adapted CIMMYT Zimbabwe lines. The cross combinations that were successfully pollinated resulted in a total of 30 single cross hybrids and five stress tolerant donor parents were dropped from the evaluations as they did not have all cross combinations with the testers. These single cross hybrids were evaluated under optimum, sandy and managed drought conditions using a 0.1 alpha lattice design with two replications in the 2013-14 summer and winter season. The objectives of this study were (i) to estimate combining ability effects among the drought and heat stress tolerant donors and CIMMYT Zimbabwe adapted maize inbred lines, (ii) to classify the stress tolerant donor lines into heterotic group A and B using CML312 and CML444 as testers and (iii) to evaluate GXE interaction of the single crosses developed. For grain yield and other secondary traits evaluated across environments, significant GCA and SCA effects indicated the importance of both additive and non-additive gene effects in the expression of these traits. Additive gene action contributed more to genotypic variation amongst testcrosses for the traits measured as evidenced by the higher mean squares for lines and testers than their interaction. For grain yield, additive gene action due to females had much contribution to the genotypic variation therefore highlighting the importance of maternal effects in the expression of this trait. The basis used for tester identification was good GCA effects for grain yield. Lines CL1215159, CL133480, CML395and CML444 showed good GCA. For heterotic grouping using CML312 and CML444 as testers, lines CL1215159, VL062656 and CL1215158 were classified in heterotic group A and CL1215157 and CL133480 were classified in group B. In heterotic group A, the single cross CL1215159 x CML312 was identified and in heterotic group B, CL133480 x CML444 was identified as potential single cross testers. This study was therefore able to identify genotypes to be incorporated in stress breeding programmes.CIMMYT Zimbabw
Combining ability between drought and heat stress tolerant donors and adapted CIMMYT Zimbabwe maize inbred lines
No full textDrought and heat stress are major abiotic stresses limiting maize production in Zimbabwe and Africa at large. It is of great importance to evaluate the breeding value of combined drought and heat stress donor parents for development of new and locally adapted maize hybrids. A North Carolina Design II (NCDII) mating scheme was used for crossing 10 combined drought and heat stress tolerant donor lines and six adapted CIMMYT Zimbabwe lines. The cross combinations that were successfully pollinated resulted in a total of 30 single cross hybrids and five stress tolerant donor parents were dropped from the evaluations as they did not have all cross combinations with the testers. These single cross hybrids were evaluated under optimum, sandy and managed drought conditions using a 0.1 alpha lattice design with two replications in the 2013-14 summer and winter season. The objectives of this study were (i) to estimate combining ability effects among the drought and heat stress tolerant donors and CIMMYT Zimbabwe adapted maize inbred lines, (ii) to classify the stress tolerant donor lines into heterotic group A and B using CML312 and CML444 as testers and (iii) to evaluate GXE interaction of the single crosses developed. For grain yield and other secondary traits evaluated across environments, significant GCA and SCA effects indicated the importance of both additive and non-additive gene effects in the expression of these traits. Additive gene action contributed more to genotypic variation amongst testcrosses for the traits measured as evidenced by the higher mean squares for lines and testers than their interaction. For grain yield, additive gene action due to females had much contribution to the genotypic variation therefore highlighting the importance of maternal effects in the expression of this trait. The basis used for tester identification was good GCA effects for grain yield. Lines CL1215159, CL133480, CML395and CML444 showed good GCA. For heterotic grouping using CML312 and CML444 as testers, lines CL1215159, VL062656 and CL1215158 were classified in heterotic group A and CL1215157 and CL133480 were classified in group B. In heterotic group A, the single cross CL1215159 x CML312 was identified and in heterotic group B, CL133480 x CML444 was identified as potential single cross testers. This study was therefore able to identify genotypes to be incorporated in stress breeding programmes.,CIMMYT Zimbabw
Combining Ability between Drought and Heat Stress Tolerant Donors and Adapted Cimmyt Zimbabwe Maize Inbred Lines
No full textDrought and heat stress are major abiotic stresses limiting maize production in Zimbabwe and Africa at large. It is of great importance to evaluate the breeding value of combined drought and heat stress donor parents for development of new and locally adapted maize hybrids. A North Carolina Design II (NCDII) mating scheme was used for crossing 10 combined drought and heat stress tolerant donor lines and six adapted CIMMYT Zimbabwe lines. The cross combinations that were successfully pollinated resulted in a total of 30 single cross hybrids and five stress tolerant donor parents were dropped from the evaluations as they did not have all cross combinations with the testers. These single cross hybrids were evaluated under optimum, sandy and managed drought conditions using a 0.1 alpha lattice design with two replications in the 2013-14 summer and winter season. The objectives of this study were (i) to estimate combining ability effects among the drought and heat stress tolerant donors and CIMMYT Zimbabwe adapted maize inbred lines, (ii) to classify the stress tolerant donor lines into heterotic group A and B using CML312 and CML444 as testers and (iii) to evaluate GXE interaction of the single crosses developed. For grain yield and other secondary traits evaluated across environments, significant GCA and SCA effects indicated the importance of both additive and non-additive gene effects in the expression of these traits. Additive gene action contributed more to genotypic variation amongst testcrosses for the traits measured as evidenced by the higher mean squares for lines and testers than their interaction. For grain yield, additive gene action due to females had much contribution to the genotypic variation therefore highlighting the importance of maternal effects in the expression of this trait. The basis used for tester identification was good GCA effects for grain yield. Lines CL1215159, CL133480, CML395and CML444 showed good GCA. For heterotic grouping using CML312 and CML444 as testers, lines CL1215159, VL062656 and CL1215158 were classified in heterotic group A and CL1215157 and CL133480 were classified in group B. In heterotic group A, the single cross CL1215159 x CML312 was identified and in heterotic group B, CL133480 x CML444 was identified as potential single cross testers. This study was therefore able to identify genotypes to be incorporated in stress breeding programmes
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
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