961 resultados para Barley Roots
Mapping genes for resistance to net form of net blotch and strip rust in barley (Hordeum vulgare L.)
Resumo:
A dihaploid mapping population comprising 65 lines was developed between barley parent varieties Tallon and Kaputar and used to construct a genetic linkage map. This map, comprising 195 amplified fragment length polymorphism and 38 simple sequence repeat markers, was used to identify markers linked to the net form of net blotch (Pyrenophora teres f.sp. teres) and to stripe rust (Puccinia striiformis f.sp. hordei) in barley. The population was screened with five pathotypes of net blotch at the seedling stage in the glasshouse and subjected to a natural inoculation in Hermitage, Queensland. Stripe rust screening was conducted at the adult plant stage in Toluca, Mexico. Analyses of the markers were performed using Mapmanager and Qgene software. One region on chromosome 6H was highly significantly associated with resistance to the net blotch (R2 = 79%). This association was consistent for all pathotypes studied. One region on chromosome 5H was found to be highly significantly associated with resistance to stripe rust (R2= 65%). There are a number of very closely linked markers showing strong associations in these regions, and these markers present an opportunity for marker assisted selection of these traits in barley breeding programs.
Resumo:
Over the last 30 years, the field of problem structuring methods (PSMs) has been pioneered by a handful of 'gurus'—the most visible of whom have contributed other viewpoints to this special issue. As this generation slowly retires, it is opportune to survey the field and their legacy. We focus on the progress the community has made up to 2000, as work that started afterwards is ongoing and its impact on the field will probably only become apparent in 5–10 years time. We believe that up to 2000, research into PSMs was stagnating. We believe that this was partly due to a lack of new researchers penetrating what we call the 'grass-roots community'—the community which takes an active role in developing the theory and application of problem structuring. Evidence for this stagnation (or lack of development) is that, in 2000, many PSMs still relied heavily on the same basic methods proposed by the originators nearly 30 years earlier—perhaps only supporting those methods with computer software as a sign of development. Furthermore, no new methods had been integrated into the literature which suggests that revolutionary development, at least by academics, has stalled. We are pleased to suggest that from papers in this double special issue on PSMs this trend seems over because new authors report new PSMs and extend existing PSMs in new directions. Despite these recent developments of the methods, it is important to examine why this apparent stagnation took place. In the following sections, we identify and elaborate a number of reasons for it. We also consider the trends, challenges and opportunities that the PSM community will continue to face. Our aim is to evaluate the pre-2000 PSM community to encourage its revolutionary development post-2006 and offer directions for the long term sustainability of the field.
Resumo:
DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY WITH PRIOR ARRANGEMENT
Resumo:
The well-established sociolinguistic literature on complimenting claims that compliments are formulaic (Manes and Wolfson 1981). The purpose of this thesis is to demonstrate that the claim is invalid, to describe an alternative approach to the study of compliments, and to draw on an extensive collection of compliments in order to show that complimenting is a diverse, interactive process. A prerequisite for such work is a means of deciding whether a given utterance is a compliment, but this issue is neglected in the literature. The conversation analytic notion of preference appeared capable of providing this criterion, but research revealed that it was too ill-defined to serve such a purpose. The thesis was, therefore, obliged to clarify the notion of preference before applying it to a study of compliments. The necessary clarification was found in the enthnomethodological roots of conversation analysis, and the thesis provides a clear and consistent means of determining whether utterances are preferred to dispreferred. The criteria used in the determination of preference are applied, in the final chapter, to the study of compliments. The results of the study contrast markedly with those of the sociolinguistic researchers, and they provide significant grounds for rejecting the claim that compliments are formulaic.
Resumo:
In this paper we present F LQ, a quadratic complexity bound on the values of the positive roots of polynomials. This bound is an extension of FirstLambda, the corresponding linear complexity bound and, consequently, it is derived from Theorem 3 below. We have implemented FLQ in the Vincent-Akritas-Strzeboński Continued Fractions method (VAS-CF) for the isolation of real roots of polynomials and compared its behavior with that of the theoretically proven best bound, LM Q. Experimental results indicate that whereas F LQ runs on average faster (or quite faster) than LM Q, nonetheless the quality of the bounds computed by both is about the same; moreover, it was revealed that when VAS-CF is run on our benchmark polynomials using F LQ, LM Q and min(F LQ, LM Q) all three versions run equally well and, hence, it is inconclusive which one should be used in the VAS-CF method.
Resumo:
In this paper a new method which is a generalization of the Ehrlich-Kjurkchiev method is developed. The method allows to find simultaneously all roots of the algebraic equation in the case when the roots are supposed to be multiple with known multiplicities. The offered generalization does not demand calculation of derivatives of order higher than first simultaneously keeping quaternary rate of convergence which makes this method suitable for application from practical point of view.
Resumo:
2000 Mathematics Subject Classification: 12D10.