9,722 research outputs found

    Multiparental mapping of plant height and flowering time QTL in partially isogenic sorghum families.

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    Sorghum varieties suitable for grain production at temperate latitudes show dwarfism and photoperiod insensitivity, both of which are controlled by a small number of loci with large effects. We studied the genetic control of plant height and flowering time in five sorghum families (A-E), each derived from a cross between a tropical line and a partially isogenic line carrying introgressions derived from a common, temperate-adapted donor. A total of 724 F2:3 lines were phenotyped in temperate and tropical environments for plant height and flowering time and scored at 9139 SNPs using genotyping-by-sequencing. Biparental mapping was compared with multiparental mapping in different subsets of families (AB, ABC, ABCD, and ABCDE) using both a GWAS approach, which fit each QTL as a single effect across all families, and using a joint linkage approach, which fit QTL effects as nested within families. GWAS using all families (ABCDE) performed best at the cloned Dw3 locus, whereas joint linkage using all families performed best at the cloned Ma1 locus. Both multiparental approaches yielded apparently synthetic associations due to genetic heterogeneity and were highly dependent on the subset of families used. Comparison of all mapping approaches suggests that a GA2-oxidase underlies Dw1, and that a mir172a gene underlies a Dw1-linked flowering time QTL

    Indirect Dissociative Recombination of LiH+^+ Molecules Fueled by Complex Resonance Manifolds

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    The LiH+^{+} molecule is prototypical of the indirect dissociative recombination (DR) process, in which a colliding electron destroys the molecule through Rydberg capture pathways. This Letter develops the first quantitative test of the Siegert state multichannel quantum defect theory description of indirect DR for a diatomic molecular ion. The R-matrix approach is adopted to calculate ab-initio quantum defects, functions of the internuclear distance that characterize both Rydberg states and the zero-energy collisions of electrons with LiH+^{+} ions. The calculated DR rate coefficient agrees accurately with recent experimental data (S. Krohn et al, Phys. Rev. Lett. 86, 4005). We identify the doorways to fast indirect DR as complex resonance manifolds, which couple closed channels having both high and low principal quantum numbers. This sheds new light on the competition between direct and indirect DR pathways, and suggests the reason why previous theory underestimated the DR rate by an order of magnitude.Comment: Submitted to PR

    Market orientation, competitive advantage, and performance: A demand-based perspective

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    This study assesses how customer value affects a firm's market orientation and consequently, competitive advantage and organizational performance in a service industry - the global hotel industry. The findings show that if a firm perceives its customers as valuing service, the firm is more likely to adopt both a customer and a competitor orientation; if the firm thinks its customers are price sensitive, the firm tends to develop a competitor orientation. Moreover, the greater a firm's customer orientation, the more the firm is able to develop a competitive advantage based on innovation and market differentiation. In contrast, a competitor orientation has a negative effect on a firm's market differentiation advantage. Finally, innovation and market differentiation advantages lead to greater market performance (e.g., perceived quality, customer satisfaction) and in turn, higher financial performance (e.g., profit, market share). © 2008 Elsevier Inc. All rights reserved.postprin

    The rôle of knowledge in system risk identification and assessment: The 2014 Ebola outbreak

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    This is the author accepted manuscript. The final version is available from Palgrave Macmillan via the DOI in this recordCurrent approaches to risk management stress the need for dynamic approaches to risk identification aimed at reducing the expected consequences of undesired outcomes. We contend that these approaches place insufficient emphasis on the system knowledge available to the assessor, particularly in respect of three related factors, namely the dynamic behaviour of the system under threat, the role of human agents and the knowledge availability to those agents. In this paper, we address the rôle of knowledge use and availability in critical human activity systems. We emphasise two distinctions: that between information and knowledge used in these systems, and that between knowledge about the system and knowledge deployed within it, the latter forming part of the system itself. Using the ongoing 2014–2015 West African Ebola outbreak as an example, we offer a practical procedure using the well-known systems dynamics technique in its qualitative form for the identification of risks and appropriate policies for managing those risks

    Gender differences and correlates of extreme dieting behaviours in US adolescents.

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    This article examined correlates of and gender differences in extreme dieting behaviours among 15,425 US adolescents from the 2011 Youth Risk Behavior Survey. Suicidal thoughts and plans and binge drinking were related to extreme dieting behaviours in females, but not in males. Suicide attempts, daily smoking and marijuana use were related to extreme dieting behaviours in males, but not females. Results suggest extreme dieting behaviours are associated with a range of negative psychosocial factors and substance use behaviours, and that these differ for boys and girls. Additional research is required to elucidate these relationships, and these results provide a focus for future research, prevention and intervention efforts

    Vacuum phototriodes for the CMS electromagnetic calorimeter endcap

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    The measurement of scintillation light from the lead tungstate crystals of the Compact Muon Solenoid (CMS) electromagnetic calorimeter (ECAL) poses a substantial technical challenge, particularly in the endcap regions, where the radiation levels are highest. The photodetectors must be fast, sensitive, radiationhard, and operate with significant internal gain in a magnetic field of 4 Tesla. The measured performance characteristics of the first batches of series production vacuum phototriodes (VPT), developed to satisfy the needs of CMS, will be described

    Defining the fracture population in a pragmatic multicentre randomised controlled trial : PROFHER and the Neer classification of proximal humeral fractures

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    OBJECTIVES: Accurate characterisation of fractures is essential in fracture management trials. However, this is often hampered by poor inter-observer agreement. This article describes the practicalities of defining the fracture population, based on the Neer classification, within a pragmatic multicentre randomised controlled trial in which surgical treatment was compared with non-surgical treatment in adults with displaced fractures of the proximal humerus involving the surgical neck. METHODS: The trial manual illustrated the Neer classification of proximal humeral fractures. However, in addition to surgical neck displacement, surgeons assessing patient eligibility reported on whether either or both of the tuberosities were involved. Anonymised electronic versions of baseline radiographs were sought for all 250 trial participants. A protocol, data collection tool and training presentation were developed and tested in a pilot study. These were then used in a formal assessment and classification of the trial fractures by two independent senior orthopaedic shoulder trauma surgeons. RESULTS: Two or more baseline radiographic views were obtained for each participant. The independent raters confirmed that all fractures would have been considered for surgery in contemporaneous practice. A full description of the fracture population based on the Neer classification was obtained. The agreement between the categorisation at baseline (tuberosity involvement) and Neer classification as assessed by the two raters was only fair (kappa 0.29). However, this disparity did not appear to affect trial findings, specifically in terms of influencing the effect of treatment on the primary outcome of the trial. CONCLUSIONS: A key reporting requirement, namely the description of the fracture population, was achieved within the context of a pragmatic multicentre randomised clinical trial. This article provides important guidance for researchers designing similar trials on fracture management.Cite this article: H. H. G. Handoll, S. D. Brealey, L. Jefferson, A. Keding, A. J. Brooksbank, A. J. Johnstone, J. J. Candal-Couto, A. Rangan. Defining the fracture population in a pragmatic multicentre randomised controlled trial: PROFHER and the Neer classification of proximal humeral fractures.Bone Joint Res 2016;5:481-489. DOI: 10.1302/2046-3758.510.BJR-2016-0132.R1

    Analyzing models of work addiction: single factor and bi-factor models of the Bergen Work Addiction Scale

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    Work addiction ('workaholism') has become an increasingly studied topic in the behavioral addictions literature and had led to the development of a number of instruments to assess it. One such instrument is the Bergen Work Addiction Scale (BWAS - Andreassen et al. 2012 Scandinavian Journal of Psychology, 53, 265-272). However, the BWAS has never been investigated in Eastern-European countries. The goal of the present study was to examine the factor structure, the reliability and cut-off scores of the BWAS in a comprehensive Hungarian sample. This study is a direct extension of the original validation of BWAS by providing results on the basis of representative data and the development of appropriate cut-off scores The study utilized an online questionnaire with a Hungarian representative sample including 500 respondents (F = 251; M age = 35.05 years) who completed the BWAS. A series of confirmatory factor analyses were carried out leading to a short, 7-item first-order factor structure and a longer 14-item seven-factor nested structure. Despite the good validity of the longer version, its reliability was not as high as it could have been. One-fifth (20.6 %) of the Hungarians who used the internet at least weekly were categorized as work addicts using the BWAS. It is recommended that researchers use the original seven items from the Norwegian scale in order to facilitate and stimulate cross-national research on addiction to work

    Is the biology of breast cancer changing? A study of hormone receptor status 1984-1986 and 1996-1997

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    Using archived tumours, those from 1984-1986 and 1996-1997 underwent immunohistochemistry for hormone receptors and grade analysis. A significant shift towards more ER-positive and low-grade disease was found; this appears to reflect screening practices, but could still influence survival
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