938 research outputs found

    Genotype x environment interaction and stability analysis for yield and yield related traits of Kabuli-type Chickpea (Cicer arietinum L.) in Ethiopia

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    Chickpea is the major pulse crop cultivated in Ethiopia. However, its production is constrained due to genotype instability and environmental variability. This research was carried out to examine the magnitude of environmental effect on yield of chickpea genotypes and to investigate the stability and adaptability of genotypes under different agro-ecologies. Seventeen (17) genotypes were evaluated in randomized complete block design (RCBD) with four replications in five locations. Various stability indices were used to assess stability and genotype by environment performances. Combined analysis of variance (ANOVA) for yield and yield components revealed highly significant (P≀0.01) differences for genotypes, environments and their interaction. The significant interaction showed genotypes respond differently across environments. At Akaki, Chefe Donsa, Debre Zeit, Dembia and Haramaya, top performing genotype were DZ-2012-CK-0001 (2933 kg/ha), Arerti (3219 kg/ha), Arerti (3560 kg/ha) DZ-2012-CK-0013 (2675 kg/ha) and Arerti (2019 kg/ha), respectively. The first two PCs explained 74.45% of the variance. Based on ASV value, DZ-2012-CK-0002 were most stable genotypes. As per AMMI biplot, Arerti and DZ-10-4 were most widely adapted genotypes. Dembia and Haramaya were most discriminative environments for genotypes. Debre Zeit and Chefe Donsa were favorable environment for genotype. Genotypes DZ-2012-CK-0004, DZ-2012-CK-0010, DZ-2012-CK-0013, DZ-2012-CK-0007 and DZ-10-4 are recommendable to Akaki, Chefe Donsa, Debre Zeit, Dembia and Haramya, respectively.Keywords: AMMI, ASV, clustering, phenologic traits, Kabuli, univariate statistics.Abbreviation: E, Environments; G, genotypes; RCBD, randomized complete block design.

    Notes

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    Notes by Robert E. Sullivan, Frederick N. Hoover, Robert Lowell Miller, Robert M. Million, F. Gerard Feeney, and James D. Sullivan

    A search for rapidly pulsating hot subdwarf stars in the GALEX survey

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    NASA's Galaxy Evolution Explorer (GALEX) provided near- and far-UV observations for approximately 77 percent of the sky over a ten-year period; however, the data reduction pipeline initially only released single NUV and FUV images to the community. The recently released Python module gPhoton changes this, allowing calibrated time-series aperture photometry to be extracted easily from the raw GALEX data set. Here we use gPhoton to generate light curves for all hot subdwarf B (sdB) stars that were observed by GALEX, with the intention of identifying short-period, p-mode pulsations. We find that the spacecraft's short visit durations, uneven gaps between visits, and dither pattern make the detection of hot subdwarf pulsations difficult. Nonetheless, we detect UV variations in four previously known pulsating targets and report their UV pulsation amplitudes and frequencies. Additionally, we find that several other sdB targets not previously known to vary show promising signals in their periodograms. Using optical follow-up photometry with the Skynet Robotic Telescope Network, we confirm p-mode pulsations in one of these targets, LAMOST J082517.99+113106.3, and report it as the most recent addition to the sdBVr class of variable stars.Comment: 11 Pages, 8 Figures, Accepted for publication in the Astrophysical Journa

    Predictive factors of clinical assays on hydroxychloroquine for COVID-19 mortality during the first year of the pandemic: A meta-synthesis

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    Background: The COVID-19 pandemic led to a violent debate about the efficacy of a repurposed drug hydroxychloroquine (HCQ) and a new broad-spectrum antiviral (remdesivir) and about randomized controlled trials (RCTs) and observational studies. To understand conflicting results in the literature, we performed a metasynthesis to determine whether intrinsic qualitative criteria within studies may predict apparent efficacy or ineffectiveness of HCQ and remdesivir. Methodology: Predictive criteria were identified through critical review of studies assessing HCQ and remdesivir for COVID-19 mortality from March to November 2020. Multiple correspondence analysis, comparative metaanalysis, and predictive value were used to explore and identify criteria associated with study outcomes. Results: Among the 61 included studies, potential conflict of interest, detailed therapeutic protocol, toxic treatment (overdose or use in contraindicated patients), known centers and doctors, and private data computing company were the most predictive criteria of the direction of effect of the studies. All 18 observational studies evaluating HCQ and reporting detailed therapeutic protocol without conflict of interest were Pro. Potential conflict of interest was a perfect predictor for remdesivir efficacy. RCTs were associated with HCQ inefficacy and potential conflict of interest. The most predictive criteria were validated and allowed perfect classification of 10 additional studies.Conclusion: In therapeutic trials on COVID-19, the major biases predicting the conclusions are not methodology nor data analysis, but conflict of interest and absence of medical expertise. The thorough search for declared or undeclared and direct or indirect conflict of interest, and medical expertise should be included in the quality criteria for the evaluation of future therapeutic studies in COVID-19 and beyond. A new checklist evaluating not only methodology but also conflict of interest and medical expertise is proposed

    High Spectral Resolution Measurement of the Sunyaev–Zel'dovich Effect Null with Z-Spec

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    The Sunyaev-Zel'dovich (SZ) effect spectrum crosses through a null where ΔT_CMB = 0 near Îœ_0 = 217 GHz. In a cluster of galaxies, Îœ0 can be shifted from the canonical thermal SZ effect value by corrections to the SZ effect scattering due to the properties of the inter-cluster medium. We have measured the SZ effect in the hot galaxy cluster RX J 1347.5 – 1145 with Z-Spec, an R ~ 300 grating spectrometer sensitive between 185 and 305 GHz. These data comprise a high spectral resolution measurement around the null of the SZ effect and clearly exhibit the transition from negative to positive ΔT_CMB over the Z-Spec band. The SZ null position is measured to be Îœ_0 = 225.8 ± 2.5(stat.) ± 1.2(sys.) GHz, which differs from the canonical null frequency by 3.0σ and is evidence for modifications to the canonical thermal SZ effect shape. Assuming the measured shift in Îœ0 is due only to relativistic corrections to the SZ spectrum, we place the limit kT_e = 17.1 ± 5.3 keV from the zero-point measurement alone. By simulating the response of the instrument to the sky, we are able to generate likelihood functions in {y_0, T_e, v_pec} space. For v_pec = 0 km s^(–1), we measure the best-fitting SZ model to be y_0 = 4.6^(+0.6)_(–0.9) × 10^(–4), T_e, 0 = 15.2^(+12)_(–7.4) keV. When v pec is allowed to vary, a most probable value of v_pec = + 450 ± 810 km s^(–1) is found

    Feedback under the microscope II: heating, gas uplift, and mixing in the nearest cluster core

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    Using a combination of deep 574ks Chandra data, XMM-Newton high-resolution spectra, and optical Halpha+NII images, we study the nature and spatial distribution of the multiphase plasma in M87. Our results provide direct observational evidence of `radio mode' AGN feedback in action, stripping the central galaxy of its lowest entropy gas and preventing star-formation. This low entropy gas was entrained with and uplifted by the buoyantly rising relativistic plasma, forming long "arms". These arms are likely oriented within 15-30 degrees of our line-of-sight. The mass of the uplifted gas in the arms is comparable to the gas mass in the approximately spherically symmetric 3.8 kpc core, demonstrating that the AGN has a profound effect on its immediate surroundings. The coolest X-ray emitting gas in M87 has a temperature of ~0.5 keV and is spatially coincident with Halpha+NII nebulae, forming a multiphase medium where the cooler gas phases are arranged in magnetized filaments. We place strong upper limits of 0.06 Msun/yr on the amount of plasma cooling radiatively from 0.5 keV and show that a uniform, volume-averaged heating mechanism could not be preventing the cool gas from further cooling. All of the bright Halpha filaments appear in the downstream region of the <3 Myr old shock front, at smaller radii than ~0.6'. We suggest that shocks induce shearing around the filaments, thereby promoting mixing of the cold gas with the ambient hot ICM via instabilities. By bringing hot thermal particles into contact with the cool, line-emitting gas, mixing can supply the power and ionizing particles needed to explain the observed optical spectra. Mixing of the coolest X-ray emitting plasma with the cold optical line emitting filamentary gas promotes efficient conduction between the two phases, allowing non-radiative cooling which could explain the lack of X-ray gas with temperatures under 0.5 keV.Comment: to appear in MNRA

    The GDR width in the excited 147 Eu compound nucleus at high angular momentum

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    Abstract High-energy Îł -rays emitted in the decay of the hot compound nucleus 147 Eu have been measured in coincidence with low-energy Îł -rays. The Îł transitions from the different residual nuclei were detected by a multiplicity filter and by Ge detectors. The employed reaction was 37 Cl + 110 Pd at bombarding energies of 160, 165 and 170 MeV. The measured high-energy Îł -ray spectra were analysed within the framework of the statistical model using the Cascade code. The GDR width in the angular momentum interval between 35 and 50 ℏ was found to increase weakly and to be rather well predicted by the thermal shape fluctuation model. Also the deformation parameter ÎČ as a function of the average angular momentum extracted from the data was found to be in general agreement with the model
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