406 research outputs found

    Characterization of morpho-phenological traits in the traditional landraces of rice

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    The landraces of rice provide a wide range of genetic variations and environmental adaptation and act as excellent genetic resources for crop improvement. Natural germplasm that has been maintained through conservation is in desperate need of rigorous investigation in order to uncover new genes or alleles to introduce into rice breeding programmes. Given this context, an investigation was done to determine the degree of genetic divergence and variability across 31 rice landraces for various productivity, physiological, and grain quality traits. On evaluation of the mean performance of landraces and the influence of characters in genetic divergence resulted in the identification of better landraces viz., Vellaikuruvikar, Karupu Kavuni, Kichidi Samba and Athur Kichadi which are better for both grain yield and quality traits that can be used to create better recombinants, by hybridization. These gene pools could be used in selective breeding to significantly enhance the agronomic characters. Out of 20 traits that were investigated,15 traits viz., height of the plant, productive tillers per plant, length of panicle, spikelets per panicle, filled grains per panicle, grain yield per plant, seedling root to shoot ratio, harvest index, head rice recovery, length of the kernel, length to breadth ratio of kernel, breadth of kernel after cooking, length to breadth ratio of kernel after cooking, gelatinization temperature and aroma were noted for high heritability and genetic advancement suggesting that additive gene action predominates, there by opening up a wide range of opportunities for these traits to be improved through simple phenotypic selection

    Assessment of genetic variability and diversity analysis in medium duration rice accessions

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    A total of 64 medium duration rice accessions were evaluated for their genetic variability and genetic divergence during Rabi season 2020 at Pandit Jawaharlal Nehru College of Agriculture and Research Institute, Karaikal. Analysis of variance revealed significant differences for all the traits considered for the study. The traits spikelets per panicle and filled grains per panicle recorded high GCV as well as PCV thereby indicating that these traits would be improved effectively through selection. Other yield component traits viz., plant height, productive tillers per plant, spikelets per panicle, filled grains per panicle, fertility per cent, grain weight and single plant yield revealed high heritability coupled with high genetic advance, indicating that simple selection could be effective for improving these characters. The D2 values and hierarchical clustering analysis grouped the 64 germplasm into seven clusters. In both the clustering methods, the genotype Gold 44 was grouped under separate clusters indicating that, this is a diverse genotype among all the genotypes taken for study. Further, genotype AD 16124 was grouped under the same cluster in both the clustering methods with the highest cluster mean for grain yield per plant. Hence, this genotype could be efficiently utilized for the yield improvement programme in rice

    A global synthesis reveals biodiversity-mediated benefits for crop production

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    Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield-related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society. [Abstract copyright: Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).

    Audit fees and book-tax differences

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    We investigate whether book-tax differences are associated with higher audit fees, a proxy for auditor risk assessments and auditor effort. Our evidence suggests that there is a significantly positive relation. Further, this association is larger for firms that appear to have managed earnings (i.e., have high accruals) relative to those that are tax avoiders (i.e., have low cash effective tax rates). Our evidence is consistent with large book-tax differences representing an observable proxy for earnings management that is associated with auditor decisions. Our study contributes to capital market research that examines audit fees, as well as other research that examines the usefulness of book-tax differences for market participants.Ernst & Young (Faculty Fellowship in Accounting

    Stacked Search for Gravitational Waves from the 2006 SGR 1900+14 Storm

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    We present the results of a LIGO search for short-duration gravitational waves (GWs) associated with the 2006 March 29 SGR 1900+14 storm. A new search method is used, "stacking'' the GW data around the times of individual soft-gamma bursts in the storm to enhance sensitivity for models in which multiple bursts are accompanied by GW emission. We assume that variation in the time difference between burst electromagnetic emission and potential burst GW emission is small relative to the GW signal duration, and we time-align GW excess power time-frequency tilings containing individual burst triggers to their corresponding electromagnetic emissions. We use two GW emission models in our search: a fluence-weighted model and a flat (unweighted) model for the most electromagnetically energetic bursts. We find no evidence of GWs associated with either model. Model-dependent GW strain, isotropic GW emission energy E_GW, and \gamma = E_GW / E_EM upper limits are estimated using a variety of assumed waveforms. The stacking method allows us to set the most stringent model-dependent limits on transient GW strain published to date. We find E_GW upper limit estimates (at a nominal distance of 10 kpc) of between 2x10^45 erg and 6x10^50 erg depending on waveform type. These limits are an order of magnitude lower than upper limits published previously for this storm and overlap with the range of electromagnetic energies emitted in SGR giant flares.Comment: 7 pages, 3 figure

    Two Sides of the Same Story: Alcohol Use and HIV Risk Taking in South India

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    This qualitative study examines the role of alcohol in sexual risk among male migrant workers and female sex workers in two South Indian states. Most men reported using alcohol for increased energy and courage prior to their sexual experiences and to reduce feelings of loneliness and isolation. Sex workers, on the other hand, often stated that they avoided alcohol prior to sex in order to stay alert and reduce the risk of violence. Both groups reported that drinking often increased male aggression and reduced condom use. Research is needed to examine the prevalence of these patterns as well as factors associated with sexual risk and violence, in order to develop targeted interventions for these groups. Future risk reduction programs may benefit from addressing safer ways of meeting the needs expressed by the participants. This may include strategies to defuse volatile situations, safe ways of improving the sexual experience, and interventions aimed at alleviating loneliness and isolation for migrants

    Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

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    We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5– 20 deg2 requires at least three detectors of sensitivity within a factor of ∼2 of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector

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    A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino
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