1,409 research outputs found

    Inheritance and QTL Analysis of Field Resistance to Ashy Stem Blight in Common Bean

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    Ashy stem blight [caused by Macrophomina phaseolina (Tassi) Goid.] can be a serious disease of common bean (Phaseolus vulgaris L.) under drought and high temperature conditions in some regions. The mode of inheritance of valuable sources of resistance is lacking. We studied inheritance of field resistance to ashy stem blight in a recombinant inbred population (’Dorado’ × XAN 176) consisting of 119 F5:7 recombinant inbred lines (RILs) tested in replicated experiments across 2 yr. A score from 1 to 9 (no disease to severe disease) was used to measure disease reaction. Moderate HNs (0.53 and 0.57) and near-normal frequency distribution of RILs for mean disease score each year indicated a lack of discrete segregation classes. The phenotypic variation across a subgroup composed of 79 RILs was further investigated with 165 randomly amplified polymorphic DNA (RAPD) markers by one-way analyses of variance and interval mapping. Five quantitative trait loci (QTL), explaining 19, 15, 15, 13, and 13% of the phenotypic variation for disease score, were detected in 1993. Three of these QTL, explaining 15,12, and 12% of the variation in disease reaction, were detected in 1994. Multiple QTL regression models (P \u3c 0.01) explained up to 47% (four loci) of the phenotypic variation for disease score in 1993 and 28% (three loci) in 1994. The five QTL, all derived from XAN 176, generally showed additive effects. These QTL-linked RAPD markers may prove useful for indirect selection of field resistance to ashy stem blight derived from XAN 176

    MINESweeper: Spectrophotometric Modeling of Stars in the Gaia Era

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    We present MINESweeper, a tool to measure stellar parameters by jointly fitting observed spectra and broadband photometry to model isochrones and spectral libraries. This approach enables the measurement of spectrophotometric distances, in addition to stellar parameters such as Teff, log(g), [Fe/H], [a/Fe], and radial velocity. MINESweeper employs a Bayesian framework and can easily incorporate a variety of priors, including Gaia parallaxes. Mock data are fit in order to demonstrate how the precision of derived parameters depends on evolutionary phase and SNR. We then fit a selection of data in order to validate the model outputs. Fits to a variety of benchmark stars including Procyon, Arcturus, and the Sun result in derived stellar parameters that are in good agreement with the literature. We then fit combined spectra and photometry of stars in the open and globular clusters M92, M13, M3, M107, M71, and M67. Derived distances, [Fe/H], [a/Fe], and log(g)-Teff, relations are in overall good agreement with literature values, although there are trends between metallicity and log(g), within clusters that point to systematic uncertainties at the ~0.1 dex level. Finally, we fit a large sample of stars from the H3 Spectroscopic Survey in which high quality Gaia parallaxes are also available. These stars are fit without the Gaia parallaxes so that the geometric parallaxes can serve as an independent test of the spectrophotometric distances. Comparison between the two reveals good agreement within their formal uncertainties after accounting for the Gaia zero point uncertainties.Comment: 20 pages, 14 figures, Accepted by Ap

    Does implementation matter if comprehension is lacking? A qualitative investigation into perceptions of advance care planning in people with cancer

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    Purpose: While advance care planning holds promise, uptake is variable and it is unclear how well people engage with or comprehend advance care planning. The objective of this study was to explore how people with cancer comprehended Advance Care Plans and examine how accurately advance care planning documentation represented patient wishes. Methods: This study used a qualitative descriptive design. Data collection comprised interviews and an examination of participants’ existing advance care planning documentation. Participants included those who had any diagnosis of cancer with an advance care plan recorded: Refusal of Treatment Certificate; Statement of Choices; and/or Enduring Power of Attorney (Medical Treatment) at one cancer treatment centre. Results: Fourteen participants were involved in the study. Twelve participants were female (86%). The mean age was 77 (range: 61-91) and participants had completed their advance care planning documentation between 8 and 72 weeks prior to the interview (mean 33 weeks). Three themes were evident from the data: Incomplete advance care planning understanding and confidence; Limited congruence for attitude and documentation; Advance care planning can enable peace of mind. Complete advance care planning understanding was unusual; most participants demonstrated partial comprehension of their own advance care plan, and some indicated very limited understanding. Participants’ attitudes and their written document congruence was limited, but advance care planning was seen as helpful. Conclusions: This study highlighted advance care planning was not a completely accurate representation of patient wishes. There is opportunity to improve how patients comprehend their own advance care planning documentation

    The effects of age on associations between markers of HIV progression and markers of metabolic function including albumin, haemoglobin and lipid concentrations.

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    OBJECTIVES: We investigated whether age modified associations between markers of HIV progression, CD4 T lymphocyte count and HIV RNA viral load (VL), and the following markers of metabolic function: albumin, haemoglobin, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC). METHODS: A retrospective analysis of data from the United Kingdom Collaborative HIV Cohort was carried out. Analyses were limited to antiretroviral-naïve subjects to focus on the impact of HIV disease itself. A total of 16670 subjects were included in the analysis. Multilevel linear regression models assessed associations between CD4 count/VL and each of the outcomes. Statistical tests for interactions assessed whether associations differed among age groups. RESULTS: After adjustment for gender and ethnicity, there was evidence that lower CD4 count and higher VL were associated with lower TC, LDL-C, haemoglobin and albumin concentrations but higher triglyceride concentrations. Age modified associations between CD4 count and albumin (P 50 years, a 50 cells/μL lower CD4 count correlated with a 2.4 [95% confidence interval (CI) 1.7-3.0], 3.6 (95% CI 3.2-4.0) and 5.1 (95% CI 4.0-6.1) g/L lower haemoglobin concentration and a 0.09 (95% CI 0.07-0.11), 0.12 (95% CI 0.11-0.13) and 0.16 (95% CI 0.13-0.19) g/L lower albumin concentration, respectively. CONCLUSIONS: We present evidence that age modifies associations between CD4 count and plasma albumin and haemoglobin levels. A given reduction in CD4 count was associated with a greater reduction in haemoglobin and albumin concentrations among older people living with HIV. These findings increase our understanding of how the metabolic impact of HIV is influenced by age

    A Diffuse Metal-Poor Component of the Sagittarius Stream Revealed by the H3 Survey

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    The tidal disruption of the Sagittarius dwarf galaxy has generated a spectacular stream of stars wrapping around the entire Galaxy. We use data from GaiaGaia and the H3 Stellar Spectroscopic Survey to identify 823 high-quality Sagittarius members based on their angular momenta. The H3 Survey is largely unbiased in metallicity, and so our sample of Sagittarius members is similarly unbiased. Stream stars span a wide range in [Fe/H] from −0.2-0.2 to ≈−3.0\approx -3.0, with a mean overall metallicity of ⟨\langle[Fe/H]⟩=−0.99\rangle=-0.99. We identify a strong metallicity-dependence to the kinematics of the stream members. At [Fe/H]>−0.8\gt -0.8 nearly all members belong to the well-known cold (σv<20\sigma_v \lt 20 km/s) leading and trailing arms. At intermediate metallicities (−1.9<-1.9 \lt[Fe/H]<−0.8\lt -0.8) a significant population (24%\%) emerges of stars that are kinematically offset from the cold arms. These stars also appear to have hotter kinematics. At the lowest metallicities ([Fe/H]≲−2\lesssim-2), the majority of stars (69%\%) belong to this kinematically-offset diffuse population. Comparison to simulations suggests that the diffuse component was stripped from the Sagittarius progenitor at earlier epochs, and therefore resided at larger radius on average, compared to the colder metal-rich component. We speculate that this kinematically diffuse, low metallicity, population is the stellar halo of the Sagittarius progenitor system.Comment: 18 pages, 12 figures, 1 table. Submitted to Ap

    Electronic structure of Fe- vs. Ru-based dye molecules

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    In order to explore whether Ru can be replaced by inexpensive Fe in dye molecules for solar cells, the differences in the electronic structure of Fe- and Ru-based dyes are investigated by X-ray absorption spectroscopy and first-principles calculations. Molecules with the metal in a sixfold, octahedral N cage, such as tris(bipyridines) and tris(phenanthrolines), exhibit a systematic downward shift of the N 1s-to-π* transition when Ru is replaced by Fe. This shift is explained by an extra transfer of negative charge from the metal to the N ligands in the case of Fe, which reduces the binding energy of the N 1s core level. The C 1s-to-π* transitions show the opposite trend, with an increase in the transition energy when replacing Ru by Fe. Molecules with the metal in a fourfold, planar N cage (porphyrins) exhibit a more complex behavior due to a subtle competition between the crystal field, axial ligands, and the 2+ vs. 3+ oxidation states.This work was supported by the National Science Foundation (NSF) under Award Nos. CHE-1026245, DMR-1121288 (MRSEC), DMR-0537588 (SRC), and by the (U.S.) Department of Energy (DOE) under Contract Nos. DE-FG02-01ER45917 (end station) and DE-AC02-05CH11231 (ALS). P. L. Cook acknowledges support from the University of Wisconsin System 2012-2013 Applied Research Grant. J. M. García-Lastra and A. Rubio acknowledge financial support from the European Research Council (ERC-2010-AdG-Proposal No. 267374), Spanish Grants (FIS2011-65702-C02-01 and PIB2010US-00652), Grupos Consolidados (IT-319-07), and European Commission project CRONOS (280879-2).Peer Reviewe
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