264 research outputs found

    Evaluation of agricultural ecosystem services in fallowing land based on farmers' participation and model simulation

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    Fallowing with green fertilizer can benefit agricultural ecosystem services (AES). Farmers in Taiwan do not implement fallow practices and plant green fertilizer because the current subsidy level (46,000 NTperha)istoolowtomanagefallowing.Thispaperdefinestheobjectiveofgovernmentagriculturepolicyorthefarmersobjectiveasmaximizationoffarmproductivity,approximatedtothevalueofsocialwelfareandAES.Farms,whichdonotfollowproperfallowingpractices,oftenhavepoorlymaintainedfallowlandorleftfarmlandabandoned.Thisresultsinnegativeenvironmentalconsequencessuchascutworminfestationsinabandonedland,whichinturncanaffectcropsinadjacentfarmlands.Theobjectivesofthisstudyaretwofold.First,itdeterminestheproperfallowingsubsidybasedontheconceptofpaymentforecosystemservicestoenticemorefarmerstoparticipateinfallowing.Second,itsimulatesthebenefitofplantinggreenmanureinfallowlandtothesupplyofAESbasedontherateoffarmerswhoarewillingtoparticipateinfallowlandpracticesandessentialparametersthatcanaffectsoilfertilitychange.Theapproachinvolvesaseriesofinterviewsandadevelopedempiricalmodel.ThevalueofAESwhentherateoffarmerparticipationis100 per ha) is too low to manage fallowing. This paper defines the objective of government agriculture policy or the farmer’s objective as maximization of farm productivity, approximated to the value of social welfare and AES. Farms, which do not follow proper fallowing practices, often have poorly maintained fallow land or left farmland abandoned. This results in negative environmental consequences such as cutworm infestations in abandoned land, which in turn can affect crops in adjacent farmlands. The objectives of this study are twofold. First, it determines the proper fallowing subsidy based on the concept of payment for ecosystem services to entice more farmers to participate in fallowing. Second, it simulates the benefit of planting green manure in fallow land to the supply of AES based on the rate of farmers who are willing to participate in fallow land practices and essential parameters that can affect soil fertility change. The approach involves a series of interviews and a developed empirical model. The value of AES when the rate of farmer participation is 100% represents a 1.5% increase in AES (448,317,000 NTperha)istoolowtomanagefallowingThispaperdefinestheobjectiveofgovernmentagriculturepolicyorthefarmer’sobjectiveasmaximizationoffarmproductivityapproximatedtothevalueofsocialwelfareandAESFarmswhichdonotfollowproperfallowingpracticesoftenhavepoorlymaintainedfallowlandorleftfarmlandabandonedThisresultsinnegativeenvironmentalconsequencessuchascutworminfestationsinabandonedlandwhichinturncanaffectcropsinadjacentfarmlandsTheobjectivesofthisstudyaretwofoldFirstitdeterminestheproperfallowingsubsidybasedontheconceptofpaymentforecosystemservicestoenticemorefarmerstoparticipateinfallowingSeconditsimulatesthebenefitofplantinggreenmanureinfallowlandtothesupplyofAESbasedontherateoffarmerswhoarewillingtoparticipateinfallowlandpracticesandessentialparametersthatcanaffectsoilfertilitychangeTheapproachinvolvesaseriesofinterviewsandadevelopedempiricalmodelThevalueofAESwhentherateoffarmerparticipationis100 ) over the value at the current participation rate of 14%. This study further concludes that the appropriate fallowing subsidy has a large positive impact on AES and social welfare (e.g., benefit from food and biofuel supplies) and is seen as a basis of ecological governance for sustainable agro-ecosystems

    Differential expressions of antioxidant status in aging rats: the role of transcriptional factor Nrf2 and MAPK signaling pathway

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    Antioxidant enzymes (AOEs) play an important role in the protection of cells against reactive oxygen species and facilitate the prevention of oxidative stress-induced aging. In the present study, the antioxidant indices, including the content of peroxidation product and the expression of AOEs in rat livers of varying ages (2, 12 and 18-24 months old) were evaluated. Erythrocytes haemolysis induced by free radicals showed significant age-dependent increases (P < 0.05). The content of oxidation products in livers showed that increasing age was associated with serious oxidative injury. The activities of AOEs decreased with increasing age. Expression of the antioxidant and age-related gene, klotho, decreased with increasing age. Western blot assay showed that aged rats experience higher levels of oxidative stress. Nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) exhibited an age-dependent decrease. Additionally, the mitogen-activated protein kinase cascade (MAPK) played a regulatory role in signaling transduction. Overall, we suggest that age-related declines of the antioxidant defense are closely involved with the expression of Nrf2 and are regulated by the MAPK family

    A Pre-Landing Assessment of Regolith Properties at the InSight Landing Site

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    This article discusses relevant physical properties of the regolith at the Mars InSight landing site as understood prior to landing of the spacecraft. InSight will land in the northern lowland plains of Mars, close to the equator, where the regolith is estimated to be ≥3--5 m thick. These investigations of physical properties have relied on data collected from Mars orbital measurements, previously collected lander and rover data, results of studies of data and samples from Apollo lunar missions, laboratory measurements on regolith simulants, and theoretical studies. The investigations include changes in properties with depth and temperature. Mechanical properties investigated include density, grain-size distribution, cohesion, and angle of internal friction. Thermophysical properties include thermal inertia, surface emissivity and albedo, thermal conductivity and diffusivity, and specific heat. Regolith elastic properties not only include parameters that control seismic wave velocities in the immediate vicinity of the Insight lander but also coupling of the lander and other potential noise sources to the InSight broadband seismometer. The related properties include Poisson’s ratio, P- and S-wave velocities, Young’s modulus, and seismic attenuation. Finally, mass diffusivity was investigated to estimate gas movements in the regolith driven by atmospheric pressure changes. Physical properties presented here are all to some degree speculative. However, they form a basis for interpretation of the early data to be returned from the InSight mission.Additional co-authors: Nick Teanby and Sharon Keda

    Systematic Review of Medicine-Related Problems in Adult Patients with Atrial Fibrillation on Direct Oral Anticoagulants

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    New oral anticoagulant agents continue to emerge on the market and their safety requires assessment to provide evidence of their suitability for clinical use. There-fore, we searched standard databases to summarize the English language literature on medicine-related problems (MRPs) of direct oral anticoagulants DOACs (dabigtran, rivaroxban, apixban, and edoxban) in the treatment of adults with atri-al fibrillation. Electronic databases including Medline, Embase, International Pharmaceutical Abstract (IPA), Scopus, CINAHL, the Web of Science and Cochrane were searched from 2008 through 2016 for original articles. Studies pub-lished in English reporting MRPs of DOACs in adult patients with AF were in-cluded. Seventeen studies were identified using standardized protocols, and two reviewers serially abstracted data from each article. Most articles were inconclusive on major safety end points including major bleeding. Data on major safety end points were combined with efficacy. Most studies inconsistently reported adverse drug reactions and not adverse events or medication error, and no definitions were consistent across studies. Some harmful drug effects were not assessed in studies and may have been overlooked. Little evidence is provided on MRPs of DOACs in patients with AF and, therefore, further studies are needed to establish the safety of DOACs in real-life clinical practice

    Muon reconstruction performance of the ATLAS detector in proton–proton collision data at √s = 13 TeV

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    This article documents the performance of the ATLAS muon identification and reconstruction using the LHC dataset recorded at √s = 13 TeV in 2015. Using a large sample of J/ψ→μμ and Z→μμ decays from 3.2 fb−1 of pp collision data, measurements of the reconstruction efficiency, as well as of the momentum scale and resolution, are presented and compared to Monte Carlo simulations. The reconstruction efficiency is measured to be close to 99% over most of the covered phase space (|η| 2.2, the pT resolution for muons from Z→μμ decays is 2.9 % while the precision of the momentum scale for low-pT muons from J/ψ→μμ decays is about 0.2%

    Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

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    This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented

    Search for massive, long-lived particles using multitrack displaced vertices or displaced lepton pairs in pp collisions at √s = 8 TeV with the ATLAS detector

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    Many extensions of the Standard Model posit the existence of heavy particles with long lifetimes. This article presents the results of a search for events containing at least one long-lived particle that decays at a significant distance from its production point into two leptons or into five or more charged particles. This analysis uses a data sample of proton-proton collisions at √s=8  TeV corresponding to an integrated luminosity of 20.3  fb−1 collected in 2012 by the ATLAS detector operating at the Large Hadron Collider. No events are observed in any of the signal regions, and limits are set on model parameters within supersymmetric scenarios involving R-parity violation, split supersymmetry, and gauge mediation. In some of the search channels, the trigger and search strategy are based only on the decay products of individual long-lived particles, irrespective of the rest of the event. In these cases, the provided limits can easily be reinterpreted in different scenarios

    Search for strong gravity in multijet final states produced in pp collisions at √s=13 TeV using the ATLAS detector at the LHC

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    A search is conducted for new physics in multijet final states using 3.6 inverse femtobarns of data from proton-proton collisions at √s = 13TeV taken at the CERN Large Hadron Collider with the ATLAS detector. Events are selected containing at least three jets with scalar sum of jet transverse momenta (HT) greater than 1TeV. No excess is seen at large HT and limits are presented on new physics: models which produce final states containing at least three jets and having cross sections larger than 1.6 fb with HT > 5.8 TeV are excluded. Limits are also given in terms of new physics models of strong gravity that hypothesize additional space-time dimensions

    Search for TeV-scale gravity signatures in high-mass final states with leptons and jets with the ATLAS detector at sqrt [ s ] = 13TeV

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    A search for physics beyond the Standard Model, in final states with at least one high transverse momentum charged lepton (electron or muon) and two additional high transverse momentum leptons or jets, is performed using 3.2 fb−1 of proton–proton collision data recorded by the ATLAS detector at the Large Hadron Collider in 2015 at √s = 13 TeV. The upper end of the distribution of the scalar sum of the transverse momenta of leptons and jets is sensitive to the production of high-mass objects. No excess of events beyond Standard Model predictions is observed. Exclusion limits are set for models of microscopic black holes with two to six extra dimensions
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