592 research outputs found

    Biochar Reduced Nitrous Oxide and Carbon Dioxide Emissions from Soil with Different Water and Temperature Cycles

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    Interactions among biochar, respiration, nitrification, and soils can result in biochar increasing, decreasing, or not impacting greenhouse gas (GHG) emissions. This experiment determined the impact of water-filled porosity (WFP) and corn (Zea mays L.) stover biochar on CO2 and N2O emissions in May (spring) and August (summer). The May experiment contained two N rates [0 and 224 kg Ca(NO3)2–N ha–1], whereas the August had three N rates [0, 224 kg Ca(NO3)2–N ha–1, and 224 kg (NH4)2SO4–N ha–1]. The average temperatures in the May and Augusts 2014 experiments were 14 and 24°C, respectively. Biochar reduced CO2–C emissions in the high WFP Ca(NO3)2 treatment in the May and August experiments 15.4 and 16.3 kg ha–1, respectively. Associated with the CO2–C decrease was a 15.7% reduction in the soil solution dissolved organic C. In addition, N2O–N and CO2–C emissions were not correlated in the May Ca(NO3)2 ha–1 treatment, whereas in the August experiment, N2O–N and CO2–C emissions were correlated (r2 = 0.98, P \u3c 0.01). In August, biochar increased the apparent nitrification from 16 to 25 kg NH4–N (ha × d)–1 in the low WFP (NH4)2SO4treatment, and it did not influence the nitrification rate in the high WFP (NH4)2SO4 treatment. In general, N2O–N emissions increased with WFP and N rate and were reduced 21.7% by biochar. The findings suggest that multiple mechanisms contributed to N2O emissions and seasonal differences in soil temperature could result in biochar having a mixed impact on GHG emissions

    Personalized connectome fingerprints: Their importance in cognition from childhood to adult years

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    Structural neural network architecture patterns in the human brain could be related to individual differences in phenotype, behavior, genetic determinants, and clinical outcomes from neuropsychiatric disorders. Recent studies have indicated that a personalized neural (brain) fingerprint can be identified from structural brain connectomes. However, the accuracy, reproducibility and translational potential of personalized fingerprints in terms of cognition is not yet fully determined. In this study, we introduce a dynamic connectome modeling approach to identify a critical set of white matter subnetworks that can be used as a personalized fingerprint. Several individual variable assessments were performed that demonstrate the accuracy and practicality of personalized fingerprint, specifically predicting the identity and IQ of middle age adults, and the developmental quotient in toddlers. Our findings suggest the fingerprint found by our dynamic modeling approach is sufficient for differentiation between individuals, and is also capable of predicting general intellectual ability across human development. © 2020 The AuthorsSignificance Statement We demonstrate that white matter connections obtained from high resolution medical imaging data form a personalized fingerprint is capable of estimating individual identity and neurodevelopmental variables across human life-span. This important finding provides strong evidence to support the concept of neurological identity and function through human brain connectome mapping

    Probing R-parity violating models of neutrino mass at the Tevatron via top Squark decays

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    We have estimated the limiting branching ratio of the R-parity violating (RPV) decay of the lighter top squark, \tilde t_1 \ar l^+ d (l=el=e or μ\mu and d is a down type quark of any flavor), as a function of top squark mass(\MST) for an observable signal in the di-lepton plus di-jet channel at the Tevatron RUN-II experiment with 2 fb1^{-1} luminosity. Our simulations indicate that the lepton number violating nature of the underlying decay dynamics can be confirmed via the reconstruction of \MST. The above decay is interesting in the context of RPV models of neutrino mass where the RPV couplings (λi3j\lambda'_{i3j}) driving the above decay are constrained to be small (\lsim 10^{-3} - 10^{-4} ). If t~1\tilde t_1 is the next lightest super particle - a theoretically well motivated scenario - then the RPV decay can naturally compete with the R-parity conserving (RPC) modes which also have suppressed widths. The model independent limiting BR can delineate the parameter space in specific supersymmetric models, where the dominating RPV decay is observable and predict the minimum magnitude of the RPV coupling that will be sensitive to Run-II data. We have found it to be in the same ballpark value required by models of neutrino mass, for a wide range of \MST. A comprehensive future strategy for linking top squark decays with models of neutrino mass is sketched.Comment: 28 pages, 14 Figure

    Repeating the Errors of Our Parents? Family-of-Origin Spouse Violence and Observed Conflict Management in Engaged Couples

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    Based on a developmental social learning analysis, it was hypothesized that observing parental violence predisposes partners to difficulties in managing couple conflict. Seventy-one engaged couples were assessed on their observation of parental violence in their family of origin. All couples were videotaped discussing two areas of current relationship conflict, and their cognitions during the interactions were assessed using a video-mediated recall procedure. Couples in which the male partner reported observing parental violence (male-exposed couples) showed more negative affect and communication during conflict discussions than couples in which neither partner reported observing parental violence (unexposed couples). Couples in which only the female partner reported observing parental violence (female- exposed couples) did not differ from unexposed couples in their affect or behavior. Female-exposed couples reported more negative cognitions than unexposed couples, but male-exposed couples did not differ from unexposed couples in their reported cognitions

    Decadal Variabilities in Tropospheric Nitrogen Oxides Over United States, Europe, and China

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    Global trends in tropospheric nitrogen dioxide (NO2) have changed dramatically in the past decade. Here, we investigate tropospheric NO2 variabilities over United States, Europe, and E. China in 2005–2018 to explore the mechanisms governing the variation of this critical pollutant. We found large uncertainties in the trends of anthropogenic nitrogen oxides (NOx) emissions, for example, the reductions of NOx emissions, derived with different approaches and data sets, are in the range of 35%–50% over the United States and 15%–45% over Europe in 2005–2018. By contrast, the analysis in this work indicates declines of anthropogenic NOx emissions by about 40% and 25% over the United States and Europe, respectively, in 2005–2018, and about 20% over E. China in 2012–2018. However, the shift of major NOx sources from power generation to industrial and transportation sectors has led to noticeable diminishing effects in emission controls. Furthermore, satellite measurements exhibit the influence of NO2 background levels over the United States and Europe, which offset the impacts of anthropogenic emission declines, resulting in flatter trends of tropospheric NO2 over the United States and Europe. Our analysis further reveals underestimation of background NO2 by chemical transport models, which can lead to inaccurate interpretations of satellite measurements. We use surface in-situ NO2 observations to diagnose the satellite-observed NO2 trends and find top-down NOx emissions over urban grids represent the changes in anthropogenic NOx emissions better. This work highlights the importance of comprehensive applications of different analysis approaches to better characterizing atmospheric composition evolution

    Search for R-Parity Violating Decays of Scalar Fermions at LEP

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    A search for pair-produced scalar fermions under the assumption that R-parity is not conserved has been performed using data collected with the OPAL detector at LEP. The data samples analysed correspond to an integrated luminosity of about 610 pb-1 collected at centre-of-mass energies of sqrt(s) 189-209 GeV. An important consequence of R-parity violation is that the lightest supersymmetric particle is expected to be unstable. Searches of R-parity violating decays of charged sleptons, sneutrinos and squarks have been performed under the assumptions that the lightest supersymmetric particle decays promptly and that only one of the R-parity violating couplings is dominant for each of the decay modes considered. Such processes would yield final states consisting of leptons, jets, or both with or without missing energy. No significant single-like excess of events has been observed with respect to the Standard Model expectations. Limits on the production cross- section of scalar fermions in R-parity violating scenarios are obtained. Constraints on the supersymmetric particle masses are also presented in an R-parity violating framework analogous to the Constrained Minimal Supersymmetric Standard Model.Comment: 51 pages, 24 figures, Submitted to Eur. Phys. J.

    Measurement of the Hadronic Photon Structure Function F_2^gamma at LEP2

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    The hadronic structure function of the photon F_2^gamma is measured as a function of Bjorken x and of the factorisation scale Q^2 using data taken by the OPAL detector at LEP. Previous OPAL measurements of the x dependence of F_2^gamma are extended to an average Q^2 of 767 GeV^2. The Q^2 evolution of F_2^gamma is studied for average Q^2 between 11.9 and 1051 GeV^2. As predicted by QCD, the data show positive scaling violations in F_2^gamma. Several parameterisations of F_2^gamma are in agreement with the measurements whereas the quark-parton model prediction fails to describe the data.Comment: 4 pages, 2 figures, to appear in the proceedings of Photon 2001, Ascona, Switzerlan

    A measurement of the tau mass and the first CPT test with tau leptons

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    We measure the mass of the tau lepton to be 1775.1+-1.6(stat)+-1.0(syst.) MeV using tau pairs from Z0 decays. To test CPT invariance we compare the masses of the positively and negatively charged tau leptons. The relative mass difference is found to be smaller than 3.0 10^-3 at the 90% confidence level.Comment: 10 pages, 4 figures, Submitted to Phys. Letts.

    Measurement of the B0 Lifetime and Oscillation Frequency using B0->D*+l-v decays

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    The lifetime and oscillation frequency of the B0 meson has been measured using B0->D*+l-v decays recorded on the Z0 peak with the OPAL detector at LEP. The D*+ -> D0pi+ decays were reconstructed using an inclusive technique and the production flavour of the B0 mesons was determined using a combination of tags from the rest of the event. The results t_B0 = 1.541 +- 0.028 +- 0.023 ps, Dm_d = 0.497 +- 0.024 +- 0.025 ps-1 were obtained, where in each case the first error is statistical and the second systematic.Comment: 17 pages, 4 figures, submitted to Phys. Lett.

    First Measurement of Z/gamma* Production in Compton Scattering of Quasi-real Photons

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    We report the first observation of Z/gamma* production in Compton scattering of quasi-real photons. This is a subprocess of the reaction e+e- to e+e-Z/gamma*, where one of the final state electrons is undetected. Approximately 55 pb-1 of data collected in the year 1997 at an e+e- centre-of-mass energy of 183 GeV with the OPAL detector at LEP have been analysed. The Z/gamma* from Compton scattering has been detected in the hadronic decay channel. Within well defined kinematic bounds, we measure the product of cross-section and Z/gamma* branching ratio to hadrons to be (0.9+-0.3+-0.1) pb for events with a hadronic mass larger than 60 GeV, dominated by (e)eZ production. In the hadronic mass region between 5 GeV and 60 GeV, dominated by (e)egamma* production, this product is found to be (4.1+-1.6+-0.6) pb. Our results agree with the predictions of two Monte Carlo event generators, grc4f and PYTHIA.Comment: 18 pages, LaTeX, 5 eps figures included, submitted to Physics Letters
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