7,175 research outputs found

    Testing water-soluble carbohydrate QTL effects in perennial ryegrass (Lolium perenne L.) by marker selection

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    Water-soluble carbohydrates (WSC) are an important factor determining the nutritional value of grass forage and development of genetic markers for selection of WSC traits in perennial ryegrass would benefit future breeding programmes. Quantitative trait loci (QTLs) for WSC have been published for an F-2 ryegrass mapping family. Markers showing significant associations with these QTLs were used to design narrow-based populations with homozygosity for target QTLs. Founders were selected from within the mapping family. The divergent populations produced were analysed for WSC content in the glasshouse and the field. There was evidence of complex interactions between WSC content and other factors and traits, including the scale of assessment, time/degree of sward establishment and other forage quality parameters. Differences between the divergent pairs of the various populations were small. However, differences observed between the founder selection groups were maintained and the roles of the QTL regions in regulating forage WSC content were confirmed. In general, the individual divergent populations exploited only a limited extent of the large phenotypic variation available within the mapping family. However, this study sets the scene for exploring the opportunities for marker-assisted breeding strategies for complex traits in obligate out-breeding species, and the challenges of doing this are discussed

    Weakness Is What\u27s In Between Your Legs

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    Fused silica capillary interferometer with a layer-by-layer functional coating for the analysis of chemicals content in aqueous solutions

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    A simple fused silica capillary interferometric (FSCI) sensor has been proposed and investigated for the detection and analysis of multiple chemical compounds content in aqueous solutions. The sensor was fabricated by splicing a commercially available fused silica capillary (FSC) with two single mode fibers to create a 0.7 cm long air cavity. The fiber surface was functionalized with two different polymers: poly (allylamine hydrochloride) (PAH) and sol-gel silica in sequence using a layer-by-layer deposition method. The operating principle of the sensor relies on light interference in the fused silica capillary cavity due to adhesion of the different chemical compounds on the functional coating surface. Studies of the sensors response to the presence of five different compounds in water solutions at different concentrations have been carried out and the results have been analyzed using the principal component analysis (PCA). This work is a preliminary investigation towards the development of a novel method for assessment of content and quality of alcoholic beverages in real time using functionalized FSCIs

    MUD Play : A Transformative Learning Context

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    This case study describes Multi-user domains (MUDS) as a virtual learning environment for fostering the imaginative and symbolic aspects of transformative learning by relying primarily on the work of Boyd and Freire. MUDs are an increasingly popular but largely unexplored location for adult learning

    Nonnormality and the localized control of extended systems

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    The idea of controlling the dynamics of spatially extended systems using a small number of localized perturbations is very appealing - such a setup is easy to implement in practice. However, when the distance between controllers generating the perturbations becomes large, control fails due to increasing sensitivity of the system to noise and nonlinearities. We show that this failure is due to the fact that the evolution operator for the controlled system becomes increasingly nonnormal as the distance between controllers grows. This nonnormality is the result of control and can arise even for systems whose evolution operator is normal in the absence of control.Comment: 4 pages, 4 figure

    Optical variability of the accretion disk around the intermediate mass black hole ESO 243-49 HLX-1 during the 2012 outburst

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    We present dedicated quasi-simultaneous X-ray (Swift) and optical (Very Large Telescope (VLT), V- and R-band) observations of the intermediate mass black hole candidate ESO 243-49 HLX-1 before and during the 2012 outburst. We show that the V-band magnitudes vary with time, thus proving that a portion of the observed emission originates in the accretion disk. Using the first quiescent optical observations of HLX-1, we show that the stellar population surrounding HLX-1 is fainter than V~25.1 and R~24.2. We show that the optical emission may increase before the X-ray emission consistent with the scenario proposed by Lasota et al. (2011) in which the regular outbursts could be related to the passage at periastron of a star circling the intermediate mass black hole in an eccentric orbit, which triggers mass transfer into a quasi-permanent accretion disk around the black hole. Further, if there is indeed a delay in the X-ray emission we estimate the mass-transfer delivery radius to be ~1e11 cm.Comment: 9 pages, 2 figures, accepted for publication in ApJ

    Further Observations of the Intermediate Mass Black Hole Candidate ESO 243-49 HLX-1

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    The brightest Ultra-Luminous X-ray source HLX-1 in the galaxy ESO 243-49 currently provides strong evidence for the existence of intermediate mass black holes. Here we present the latest multi-wavelength results on this intriguing source in X-ray, UV and radio bands. We have refined the X-ray position to sub-arcsecond accuracy. We also report the detection of UV emission that could indicate ongoing star formation in the region around HLX-1. The lack of detectable radio emission at the X-ray position strengthens the argument against a background AGN.Comment: 4 pages, 2 figures. Accepted 11th of Feb 2010. Contributed talk to appear in Proceedings of "X-ray Astronomy 2009: Present Status, Multi-Wavelength Approach and Future Perspectives", Bologna, Italy, September 7-11, 2009, AIP, eds. A. Comastri, M. Cappi, and L. Angelin

    A Method to Assess the Organizing Behaviors Used in Physicians\u27 Counseling of Standardized Parents after Newborn Genetic Screening

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    Well-organized conversation can improve people’s ability to comprehend and retain information. As part of a long-term effort to adapt Quality Improvement techniques for communication, we developed an explicit criteria method to assess usage of three organizing behaviors (OBs): ‘opening behaviors’ to establish goals; ‘structuring behaviors’ to guide patients through conversation; and ‘emphasizing behaviors’ that signal a need for attention. Pairs of abstractors independently reviewed transcripts in a demonstration sample of conversations between physicians and standardized parents after newborn screening identifies carrier status for sickle cell disease. Criteria for at least one OB were identified in 50/84 transcripts (60%), including 27 with at least one opening behavior (32%), 5 with at least one structuring behavior (6%), and 38 with at least one emphasizing behavior (45%). The limited number of OBs raises concern about communication after newborn screening. Assessment and improvement of OB usage may improve understanding and allow parents to more actively participate in health care

    First evidence for spectral state transitions in the ESO243-49 hyper luminous X-ray source HLX-1

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    The brightest Ultra-Luminous X-ray source (ULX), ESO 243-49 HLX-1, with a 0.2 - 10 keV X-ray luminosity of up to 10^42 erg s^-1, provides the strongest evidence to date for the existence of intermediate mass black holes. Although small scale X-ray spectral variability has already been demonstrated, we have initiated a monitoring campaign with the X-ray Telescope onboard the Swift satellite to search for luminosity-related spectral changes and to compare its behavior with the better studied stellar mass black holes. In this paper, we report a drop in the XRT count rate by a factor of ~8 which occurred simultaneously with a hardening of the X-ray spectrum. A second observation found that the source had re-brightened by a factor of ~21 which occurred simultaneously with a softening of the X-ray spectrum. This may be the first evidence for a transition between the low/hard and high/soft states.Comment: Accepted by ApJ Letter, 2 figure
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