197 research outputs found

    Non-puddled transplanting of rice reduces life cycle greenhouse gas emission

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    Wetland rice (Oryza sativa L.) production contributes 55% of agricultural greenhouse gas (GHG) emissions globally. Hence, any new technology with the potential to reduce the GHG emissions from wetland rice could make a significant contribution to total global warming mitigation by agriculture. Incorporation of conservation agriculture (CA) in the rice–based triple cropping system in the EGP remains a challenge. Measures to reduce CH4 emissions from rice fields often lead to increased N2O emissions, and this trade–off between CH4 and N2O is a major hurdle in reducing global warming potential (GWP) of wetland rice. Ideal strategies would reduce emissions of both CH4 and N2O simultaneously. A novel solution to these constraints for rice production is non-puddled transplanting of rice. The recent development of NP of rice together with residue retention is suitable for CA. A life cycle assessment (LCA) analysis of the new NP rice production technology can estimate its potential contribution to GWP. The present study was carried out to: assess the GHG emissions for conventional puddling and NP with different levels of crop residue retention; determine the hotspots contributing significantly to the GHG emissions within the system boundaries by a LCA study, and identify the causes for the predominant GHG emissions during the pre– and on–farm stages of rice production

    Increases in soil sequestered carbon under conservation agriculture cropping decrease the estimated greenhouse gas emissions of wetland rice using life cycle assessment

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    Wetland rainfed rice (Oryza sativa L.), which covers 60 million hectares in South Asia, contributes significantly to agricultural greenhouse gas (GHG) emissions. Mitigation strategies for GHG emissions by wetland rice production are of considerable importance. Life cycle assessment of GHG emissions can be used to assess the mitigation potential of new rice production practices such as seedling establishment on non-puddled soil. The aim of the study was firstly to determine the GHG mitigation potential of rain-fed rice production by changing to non-puddled transplanting and increased crop residue retention and secondly to determine the addition contribution of soil carbon sequestration to net GHG emissions with the altered crop establishment approach. A cradle to farm-gate Life Cycle Analysis was used to calculate GHG emissions associated with monsoon rice production in rice-based intensive cropping systems of Northwest Bangladesh. The non-puddled transplanting and low residue retention decreased the net life cycle assessment GHG emissions (CO2eq) by 31 % in comparison with the current puddled transplanting and increased crop residue retention. By contrast, non-puddling with increased residue retention reduced emission of the net GHG by 16 % in comparison with current puddling and low residue retention. Regardless of rice establishment practices, CH4 was the most prevalent GHG emission comprising 63 to 67 % of the total GHGs, followed by 17–20 % from CO2 emissions from the field. The GHG emissions tonne-1 rice after accounting for soil carbon storage ranged from 1.04 to 1.18 tonne CO2eq for non-puddling with low and increased crop residue retention, respectively. The inclusion of soil carbon in the footprint equation represents a 26 % reduction of estimated GHG emissions under non-puddled soil with increased residue retention. Overall, non-puddled transplanting with increased crop residue retention was an effective GHG mitigation option in wetland monsoon rice production because the increased yield and extra soil organic carbon storage more than offset its higher CH4 emissions than with low residue retention

    Strong subadditivity inequality for quantum entropies and four-particle entanglement

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    Strong subadditivity inequality for a three-particle composite system is an important inequality in quantum information theory which can be studied via a four-particle entangled state. We use two three-level atoms in Λ\Lambda configuration interacting with a two-mode cavity and the Raman adiabatic passage technique for the production of the four-particle entangled state. Using this four-particle entanglement, we study for the first time various aspects of the strong subadditivity inequality.Comment: 5 pages, 3 figures, RevTeX4, submitted to PR

    A study of the efficiency of the class of WW-states as a quantum channel

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    Recently, a new class of WW-states has been defined by Agarwal and Pati \cite{agarwal} and it has been shown that they can be used as a quantum channel for teleportation and superdense coding. In this work, we identify those three-qubit states from the set of the new class of WW-states which are most efficient or suitable for quantum teleportation. We show that with some probability ∣W1>=(1/2)(∣100>+∣010>+2∣001>)|W_1>=(1/2)(|100>+|010>+\sqrt{2}|001>) is best suited for teleportation channel in the sense that it does not depend on the input state.Comment: 7 pages, Late

    Search for H→γγ produced in association with top quarks and constraints on the Yukawa coupling between the top quark and the Higgs boson using data taken at 7 TeV and 8 TeV with the ATLAS detector

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    A search is performed for Higgs bosons produced in association with top quarks using the diphoton decay mode of the Higgs boson. Selection requirements are optimized separately for leptonic and fully hadronic final states from the top quark decays. The dataset used corresponds to an integrated luminosity of 4.5 fb−14.5 fb−1 of proton–proton collisions at a center-of-mass energy of 7 TeV and 20.3 fb−1 at 8 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. No significant excess over the background prediction is observed and upper limits are set on the tt¯H production cross section. The observed exclusion upper limit at 95% confidence level is 6.7 times the predicted Standard Model cross section value. In addition, limits are set on the strength of the Yukawa coupling between the top quark and the Higgs boson, taking into account the dependence of the tt¯H and tH cross sections as well as the H→γγ branching fraction on the Yukawa coupling. Lower and upper limits at 95% confidence level are set at −1.3 and +8.0 times the Yukawa coupling strength in the Standard Model

    Searches for lepton-flavour-violating decays of the Higgs boson in s=13\sqrt{s}=13 TeV pp\mathit{pp} collisions with the ATLAS detector

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    This Letter presents direct searches for lepton flavour violation in Higgs boson decays, H → eτ and H → Ότ , performed with the ATLAS detector at the LHC. The searches are based on a data sample of proton–proton collisions at a centre-of-mass energy √s = 13 TeV, corresponding to an integrated luminosity of 36.1 fb−1. No significant excess is observed above the expected background from Standard Model processes. The observed (median expected) 95% confidence-level upper limits on the leptonflavour-violating branching ratios are 0.47% (0.34+0.13−0.10%) and 0.28% (0.37+0.14−0.10%) for H → eτ and H → Ότ , respectively.publishedVersio

    Combination of searches for Higgs boson pairs in pp collisions at \sqrts = 13 TeV with the ATLAS detector

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    This letter presents a combination of searches for Higgs boson pair production using up to 36.1 fb(-1) of proton-proton collision data at a centre-of-mass energy root s = 13 TeV recorded with the ATLAS detector at the LHC. The combination is performed using six analyses searching for Higgs boson pairs decaying into the b (b) over barb (b) over bar, b (b) over barW(+)W(-), b (b) over bar tau(+)tau(-), W+W-W+W-, b (b) over bar gamma gamma and W+W-gamma gamma final states. Results are presented for non-resonant and resonant Higgs boson pair production modes. No statistically significant excess in data above the Standard Model predictions is found. The combined observed (expected) limit at 95% confidence level on the non-resonant Higgs boson pair production cross-section is 6.9 (10) times the predicted Standard Model cross-section. Limits are also set on the ratio (kappa(lambda)) of the Higgs boson self-coupling to its Standard Model value. This ratio is constrained at 95% confidence level in observation (expectation) to -5.0 &lt; kappa(lambda) &lt; 12.0 (-5.8 &lt; kappa(lambda) &lt; 12.0). In addition, limits are set on the production of narrow scalar resonances and spin-2 Kaluza-Klein Randall-Sundrum gravitons. Exclusion regions are also provided in the parameter space of the habemus Minimal Supersymmetric Standard Model and the Electroweak Singlet Model. For complete list of authors see http://dx.doi.org/10.1016/j.physletb.2019.135103</p

    Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb⁻Âč of pp collisions at \sqrts = 13 TeV with the ATLAS experiment

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    A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb−1 of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqÎł coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tÎł production via a left-handed (right-handed) tuÎł coupling of 36 fb (78 fb) and on the branching ratio for t→γu of 2.8×10−5 (6.1×10−5). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tÎł production via a left-handed (right-handed) tcÎł coupling of 40 fb (33 fb) and on the branching ratio for t→γc of 22×10−5 (18×10−5). © 2019 The Author(s

    The evolution of lung cancer and impact of subclonal selection in TRACERx

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    Lung cancer is the leading cause of cancer-associated mortality worldwide. Here we analysed 1,644 tumour regions sampled at surgery or during follow-up from the first 421 patients with non-small cell lung cancer prospectively enrolled into the TRACERx study. This project aims to decipher lung cancer evolution and address the primary study endpoint: determining the relationship between intratumour heterogeneity and clinical outcome. In lung adenocarcinoma, mutations in 22 out of 40 common cancer genes were under significant subclonal selection, including classical tumour initiators such as TP53 and KRAS. We defined evolutionary dependencies between drivers, mutational processes and whole genome doubling (WGD) events. Despite patients having a history of smoking, 8% of lung adenocarcinomas lacked evidence of tobacco-induced mutagenesis. These tumours also had similar detection rates for EGFR mutations and for RET, ROS1, ALK and MET oncogenic isoforms compared with tumours in never-smokers, which suggests that they have a similar aetiology and pathogenesis. Large subclonal expansions were associated with positive subclonal selection. Patients with tumours harbouring recent subclonal expansions, on the terminus of a phylogenetic branch, had significantly shorter disease-free survival. Subclonal WGD was detected in 19% of tumours, and 10% of tumours harboured multiple subclonal WGDs in parallel. Subclonal, but not truncal, WGD was associated with shorter disease-free survival. Copy number heterogeneity was associated with extrathoracic relapse within 1 year after surgery. These data demonstrate the importance of clonal expansion, WGD and copy number instability in determining the timing and patterns of relapse in non-small cell lung cancer and provide a comprehensive clinical cancer evolutionary data resource

    The artificial intelligence-based model ANORAK improves histopathological grading of lung adenocarcinoma

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    The introduction of the International Association for the Study of Lung Cancer grading system has furthered interest in histopathological grading for risk stratification in lung adenocarcinoma. Complex morphology and high intratumoral heterogeneity present challenges to pathologists, prompting the development of artificial intelligence (AI) methods. Here we developed ANORAK (pyrAmid pooliNg crOss stReam Attention networK), encoding multiresolution inputs with an attention mechanism, to delineate growth patterns from hematoxylin and eosin-stained slides. In 1,372 lung adenocarcinomas across four independent cohorts, AI-based grading was prognostic of disease-free survival, and further assisted pathologists by consistently improving prognostication in stage I tumors. Tumors with discrepant patterns between AI and pathologists had notably higher intratumoral heterogeneity. Furthermore, ANORAK facilitates the morphological and spatial assessment of the acinar pattern, capturing acinus variations with pattern transition. Collectively, our AI method enabled the precision quantification and morphology investigation of growth patterns, reflecting intratumoral histological transitions in lung adenocarcinoma
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