459 research outputs found
That\u27s Why I Stole A Kiss From You
https://digitalcommons.library.umaine.edu/mmb-vp/6521/thumbnail.jp
A multi-scale comparison of modeled and observed seasonal methane emissions in northern wetlands
Wetlands are the largest global natural methane (CH4/ source, and emissions between 50 and 70° N latitude contribute 10-30% to this source. Predictive capability of land models for northern wetland CH4 emissions is still low due to limited site measurements, strong spatial and temporal variability in emissions, and complex hydrological and biogeochemical dynamics. To explore this issue, we compare wetland CH4 emission predictions from the Community Land Model 4.5 (CLM4.5-BGC) with siteto regional-scale observations. A comparison of the CH4 fluxes with eddy flux data highlighted needed changes to the model's estimate of aerenchyma area, which we implemented and tested. The model modification substantially reduced biases in CH4 emissions when compared with CarbonTracker CH4 predictions. CLM4.5 CH4 emission predictions agree well with growing season (May-September) CarbonTracker Alaskan regional-level CH4 predictions and sitelevel observations. However, CLM4.5 underestimated CH4 emissions in the cold season (October-April). The monthly atmospheric CH4 mole fraction enhancements due to wetland emissions are also assessed using the Weather Research and Forecasting-Stochastic Time-Inverted Lagrangian Transport (WRF-STILT) model coupled with daily emissions from CLM4.5 and compared with aircraft CH4 mole fraction measurements from the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) campaign. Both the tower and aircraft analyses confirm the underestimate of cold-season CH4 emissions by CLM4.5. The greatest uncertainties in predicting the seasonal CH4 cycle are from the wetland extent, coldseason CH4 production and CH4 transport processes. We recommend more cold-season experimental studies in highlatitude systems, which could improve the understanding and parameterization of ecosystem structure and function during this period. Predicted CH4 emissions remain uncertain, but we show here that benchmarking against observations across spatial scales can inform model structural and parameter improvements
CUORE: A Cryogenic Underground Observatory for Rare Events
CUORE is a proposed tightly packed array of 1000 TeO2 bolometers, each being
a cube 5 cm on a side with a mass of 760 g. The array consists of 25 vertical
towers, arranged in a square of 5 towers by 5 towers, each containing 10 layers
of 4 crystals. The design of the detector is optimized for ultralow-background
searches: for neutrinoless double beta decay of 130Te (33.8% abundance), cold
dark matter, solar axions, and rare nuclear decays. A preliminary experiment
involving 20 crystals 3x3x6 cm3 of 340 g has been completed, and a single CUORE
tower is being constructed as a smaller scale experiment called CUORICINO. The
expected performance and sensitivity, based on Monte Carlo simulations and
extrapolations of present results, are reported.Comment: 39 pages, 12 figures, submitted to NI
SABINA + Hong Kong: a territory wide study of prescribing trends and outcomes associated with the use of short-acting β2 agonists in the Chinese population
Background: Excessive use of short-acting β2 agonists (SABA) in patients with asthma continues to be a notable concern due to its link to higher mortality rates. Global relevance of SABA overuse in asthma management cannot be understated, it poses significant health risk to patients with asthma and imposes burden on healthcare systems. This study, as part of global SABINA progamme, aimed to describe the prescribing patterns and clinical outcomes associated with SABA use in the Chinese population. Methods: Retrospective cohort study was conducted using anonymized electronic healthcare records of Clinical Data Analysis and Reporting System (CDARS) from Hong Kong Hospital Authority (HA). Patients newly diagnosed with asthma between 2011 and 2018 and aged ≥12 years were included, stratified by SABA use (≤2, 3–6, 7–10, or ≥11 canisters/year) during one-year baseline period since asthma diagnosis date. Patients were followed up from one-year post-index until earliest censoring of events: outcome occurrence and end of study period (31 December 2020). Cox proportional regression and negative binomial regression were used to estimate the mortality risk and frequency of hospital admissions associated with SABA use respectively, after adjusting for age, sex, Charlson Comorbidity Index (CCI), and inhaled corticosteroid (ICS) dose. Outcomes include all-cause, asthma-related, and respiratory-related mortality, frequency of hospital admissions for any cause, and frequency of hospital admissions due to asthma. Results: 17,782 patients with asthma (mean age 46.7 years, 40.8% male) were included and 59.1% of patients were overusing SABA (≥ 3 canisters per year). Each patient was prescribed a median of 5.61 SABA canisters/year. SABA overuse during baseline period was associated with higher all-cause mortality risk compared to patients with ≤2 canisters/year. Association was dose-dependent, highest risk in those used ≥11 canisters/year (adjusted hazard ratio: 1.42, 95% CI: 1.13, 1.79) and 3–6 canisters/year (adjusted hazard ratio: 1.22, 95% CI: 1.00, 1.50). Higher SABA prescription volume associated with increased frequency of hospital admissions with greatest risk observed in 7–10 canisters/year subgroup (adjusted rate ratio: 4.81, 95% CI: 3.66, 6.37). Conclusions: SABA overuse is prevalent and is associated with increased all-cause mortality risk and frequency of hospital admissions among the patients with asthma in Hong Kong
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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