1,721,051 research outputs found
Winter hardiness in faba bean: Physiology and breeding
No full textWinter types of faba bean (Vicia faba L.) have existed for at least 200 years. Their superior use of the growing season confers strong yield advantages over spring beans. Nevertheless, yield increases have been slower than in many other crops. There are few sources of winter hardiness and efforts are in progress to combine favourable alleles from accessions such as Cote D'Or and BPL 4628 to increase the crop's tolerance to frost. Vernalization requirements are quantitative, as vernalization hastens flowering rather than allowing it. Hardening is associated with increases in fatty acid desaturation of membrane lipids and increases in content of soluble osmoprotectants such as proline. Other osmotically active factors such as glycinebetaine, trehalose and antifreeze proteins have not yet been reported for faba bean. Frost tolerance increases after hardening and shows good heritability (h(2) = 0.89). Three QTLs (3.6 < LOD < 4.6) have been identified for frost tolerance (explaining 8.6% of the phenotypic variation), and further QTLs for hardening response and cell membrane fatty acid composition. Information on responsive genes and the mode of their action is increasingly available from model plant species but most remains as yet untested in faba bean. There is clear potential for increasing the winter hardiness and yield of winter faba bean so it can be grown in a wider area than at present. (C) 2008 Elsevier B.V. All rights reserved.Joyce Pennycooke, Ohio, US
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
Faba bean adaptation to autumn sowing under European climates
No full textFaba bean (Vicia faba L.) is an important grain legume widely grown as a spring crop to avoid frost damage. However, there is interest in winter types for the expected benefits in grain yield as compared to spring ones. In the current experiments, we compared field performance in autumn sowings of 15 faba bean winter-type cultivars that were sown in two consecutive autumns in 12 climatically contrasting sites in Austria, France, Germany, Spain, and the UK. GGE biplot analyses (genotype plus genotype-by-environment interaction) were conducted to evaluate yield performance of faba bean genotypes and identification of mega-environments. Crossover genotype x environment was large and mainly due to the geoclimatic area. GGE biplot allowed identification of three mega-environments, namely continental, oceanic, and Mediterranean. Due to the climatic diversity of the environments, no cultivar performed well in all environments. Cultivars Clipper, Castel, Target, Wizard, and Gabl-107 performed well in oceanic mega-environment, whereas cultivars Castel, HIX, and Target performed well in continental mega-environment. None of the studied cultivars were suited to Mediterranean environments, and only Irena was able to give some modest yield at Cordoba. The average tester coordinate (defined by the average of first and second principal components of all environments) allowed to evaluate cultivars for their yielding ability and stability and to evaluate environments for their discriminating ability and to be more representative of the mega-environment. Thus, Wizard and Gabl-107 were the highest yielding cultivars being relatively stable over oceanic and continental environments. In contrast, the cultivars Irena and Divine yielded poorly at all environments. The results support the specific breeding for each major geoclimatic zone based on distinct genetic bases and selection environments
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
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
The FIGS (Focused Identification of Germplasm Strategy) Approach Identifies Traits Related to Drought Adaptation in Vicia faba Genetic Resources
No full textEfficient methods to explore plant agro-biodiversity for climate change adaptive traits are urgently required. The focused
identification of germplasm strategy (FIGS) is one such approach. FIGS works on the premise that germplasm is likely to
reflect the selection pressures of the environment in which it developed. Environmental parameters describing plant
germplasm collection sites are used as selection criteria to improve the probability of uncovering useful variation. This study
was designed to test the effectiveness of FIGS to search a large faba bean (Vicia faba L.) collection for traits related to
drought adaptation. Two sets of faba bean accessions were created, one from moisture-limited environments, and the other
from wetter sites. The two sets were grown under well watered conditions and leaf morpho-physiological traits related to
plant water use were measured. Machine-learning algorithms split the accessions into two groups based on the evaluation
data and the groups created by this process were compared to the original climate-based FIGS sets. The sets defined by trait
data were in almost perfect agreement to the FIGS sets, demonstrating that ecotypic differentiation driven by moisture
availability has occurred within the faba bean genepool. Leaflet and canopy temperature as well as relative water content
contributed more than other traits to the discrimination between sets, indicating that their utility as drought-tolerance
selection criteria for faba bean germplasm. This study supports the assertion that FIGS could be an effective tool to enhance
the discovery of new genes for abiotic stress adaptation
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