1,280 research outputs found

    A Fr\'{e}chet law and an Erd\"os-Philipp law for maximal cuspidal windings

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    In this paper we establish a Fr\'{e}chet law for maximal cuspidal windings of the geodesic flow on a Riemannian surface associated with an arbitrary finitely generated, essentially free Fuchsian group with parabolic elements. This result extends previous work by Galambos and Dolgopyat and is obtained by applying Extreme Value Theory. Subsequently, we show that this law gives rise to an Erd\"os-Philipp law and to various generalised Khintchine-type results for maximal cuspidal windings. These results strengthen previous results by Sullivan, Stratmann and Velani for Kleinian groups, and extend earlier work by Philipp on continued fractions, which was inspired by a conjecture of Erd\"os

    Transcriptomic characterization of two major Fusarium resistance quantitative trait loci (QTLs), Fhb1 and Qfhs.ifa-5A, identifies novel candidate genes

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    Fusarium head blight, caused by Fusarium graminearum, is a devastating disease of wheat. We developed near-isogenic lines (NILs) differing in the two strongest known F. graminearum resistance quantitative trait loci (QTLs), Qfhs.ndsu-3BS (also known as resistance gene Fhb1) and Qfhs.ifa-5A, which are located on the short arm of chromosome 3B and on chromosome 5A, respectively. These NILs showing different levels of resistance were used to identify transcripts that are changed significantly in a QTL-specific manner in response to the pathogen and between mock-inoculated samples. After inoculation with F. graminearum spores, 16 transcripts showed a significantly different response for Fhb1 and 352 for Qfhs.ifa-5A. Notably, we identified a lipid transfer protein which is constitutively at least 50-fold more abundant in plants carrying the resistant allele of Qfhs.ifa-5A. In addition to this candidate gene associated with Qfhs.ifa-5A, we identified a uridine diphosphate (UDP)-glycosyltransferase gene, designated TaUGT12887, exhibiting a positive difference in response to the pathogen in lines harbouring both QTLs relative to lines carrying only the Qfhs.ifa-5A resistance allele, suggesting Fhb1 dependence of this transcript. Yet, this dependence was observed only in the NIL with already higher basal resistance. The complete cDNA of TaUGT12887 was reconstituted from available wheat genomic sequences, and a synthetic recoded gene was expressed in a toxin-sensitive strain of Saccharomyces cerevisiae. This gene conferred deoxynivalenol resistance, albeit much weaker than that observed with the previously characterized barley HvUGT13248

    The employment consequences of private equity acquisitions: The case of institutional buy outs

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    There is a growing controversy as to the impact of private equity acquisitions, especially in terms of their impact on employment and subsequent organizational performance. It has been suggested that closer owner supervision and the injection of a new management team revitalize the acquired organization and unlock dormant capabilities and value. However, both politicians and trade unionists suggest that private equity acquirers may significantly reallocate value away from employees to short term investors, typically through layoffs and reduced wages, which may undermine future organizational sustainability. This article investigates this in the context of a sample of institutional buy outs (IBOs) undertaken in the UK between 1997 and 2006. Specifically we examine the impact of IBOs on both employment and remuneration against two control groups of non-acquired firms. In designing our study we follow the empirical approach taken by Conyon et al. (2001, 2002) in investigating the employment consequences of regular takeovers. Our main finding is a significant loss in employment in firms subject to an IBO in the year immediately following the acquisition as well as lower wage rates, when compared to either of the two control groups. Furthermore, we find no evidence of a subsequent improvement either in productivity or profitability in the acquired businesses. © 2014 Elsevier B.V

    Influence of climate shifts on decadal variations of surface solar radiation in Alaska

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    From past studies it has been known that the Pacific Decadal Oscillation (PDO) shifted toward a positive mode in 1976 and a new climate regime occurred that produced a warming of the mean annual and seasonal temperatures and associated increases in cloud cover and precipitation in the North Pacific including Alaska. In this study, this climate shift is examined with regard to the variations in surface solar radiation before and after 1976 during the period 1961–2005. The results show greatest changes occurring in the southeast region in winter with a significant rise of 1.67% y
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