29 research outputs found
Measurement of the Negative Muon Anomalous Magnetic Moment to 0.7 ppm
The anomalous magnetic moment of the negative muon has been measured to a
precision of 0.7 parts per million (ppm) at the Brookhaven Alternating Gradient
Synchrotron. This result is based on data collected in 2001, and is over an
order of magnitude more precise than the previous measurement of the negative
muon. The result a_mu= 11 659 214(8)(3) \times 10^{-10} (0.7 ppm), where the
first uncertainty is statistical and the second is sytematic, is consistend
with previous measurements of the anomaly for the positive and negative muon.
The average for the muon anomaly a_{mu}(exp) = 11 659 208(6) \times 10^{-10}
(0.5ppm).Comment: 4 pages, 4 figures, submitted to Physical Review Letters, revised to
reflect referee comments. Text further revised to reflect additional referee
comments and a corrected Fig. 3 replaces the older versio
First Results from the LUX Dark Matter Experiment at the Sanford Underground Research Facility
The Large Underground Xenon (LUX) experiment, a dual-phase xenon
time-projection chamber operating at the Sanford Underground Research Facility
(Lead, South Dakota), was cooled and filled in February 2013. We report results
of the first WIMP search dataset, taken during the period April to August 2013,
presenting the analysis of 85.3 live-days of data with a fiducial volume of 118
kg. A profile-likelihood analysis technique shows our data to be consistent
with the background-only hypothesis, allowing 90% confidence limits to be set
on spin-independent WIMP-nucleon elastic scattering with a minimum upper limit
on the cross section of cm at a WIMP mass of 33
GeV/c. We find that the LUX data are in strong disagreement with low-mass
WIMP signal interpretations of the results from several recent direct detection
experiments.Comment: Accepted by Phys. Rev. Lett. Appendix A included as supplementary
material with PRL articl
First Results from the LUX Dark Matter Experiment at the Sanford Underground Research Facility
The Large Underground Xenon (LUX) experiment, a dual-phase xenon
time-projection chamber operating at the Sanford Underground Research Facility
(Lead, South Dakota), was cooled and filled in February 2013. We report results
of the first WIMP search dataset, taken during the period April to August 2013,
presenting the analysis of 85.3 live-days of data with a fiducial volume of 118
kg. A profile-likelihood analysis technique shows our data to be consistent
with the background-only hypothesis, allowing 90% confidence limits to be set
on spin-independent WIMP-nucleon elastic scattering with a minimum upper limit
on the cross section of cm at a WIMP mass of 33
GeV/c. We find that the LUX data are in strong disagreement with low-mass
WIMP signal interpretations of the results from several recent direct detection
experiments.Comment: Accepted by Phys. Rev. Lett. Appendix A included as supplementary
material with PRL articl
Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980-2017: a systematic analysis for the Global Burden of Disease Study 2017.
BACKGROUND: Global development goals increasingly rely on country-specific estimates for benchmarking a nation's progress. To meet this need, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 estimated global, regional, national, and, for selected locations, subnational cause-specific mortality beginning in the year 1980. Here we report an update to that study, making use of newly available data and improved methods. GBD 2017 provides a comprehensive assessment of cause-specific mortality for 282 causes in 195 countries and territories from 1980 to 2017. METHODS: The causes of death database is composed of vital registration (VR), verbal autopsy (VA), registry, survey, police, and surveillance data. GBD 2017 added ten VA studies, 127 country-years of VR data, 502 cancer-registry country-years, and an additional surveillance country-year. Expansions of the GBD cause of death hierarchy resulted in 18 additional causes estimated for GBD 2017. Newly available data led to subnational estimates for five additional countries-Ethiopia, Iran, New Zealand, Norway, and Russia. Deaths assigned International Classification of Diseases (ICD) codes for non-specific, implausible, or intermediate causes of death were reassigned to underlying causes by redistribution algorithms that were incorporated into uncertainty estimation. We used statistical modelling tools developed for GBD, including the Cause of Death Ensemble model (CODEm), to generate cause fractions and cause-specific death rates for each location, year, age, and sex. Instead of using UN estimates as in previous versions, GBD 2017 independently estimated population size and fertility rate for all locations. Years of life lost (YLLs) were then calculated as the sum of each death multiplied by the standard life expectancy at each age. All rates reported here are age-standardised
Nondestructive determination of nutritional information in oilseed rape leaves using visible/near infrared spectroscopy and multivariate calibrations
Nitrogen, phosphorus and potassium content are the three most important nutritional parameters for growing oilseed rape. We investigated visible and near infrared (Vis/NIR) spectroscopy combined with chemometrics for the fast and nondestructive determination of nutritional information in oilseed rape leaves. A total of 154 leaf samples were collected, with 104 randomly selected as the calibration set, and the remaining 50 samples used as the validation set. The performance of eight different preprocessing methods was compared in partial least squares (PLS) models. Some effective wavelengths selected by a successive projections algorithm (SPA) were also used to develop linear SPA-PLS, nonlinear back propagation neural network (BPNN), and nonlinear least squares-support vector machine (LS-SVM) models to determine nutritional information. The best prediction models were DOSC-PLS for nitrogen with r=0.9743 and RMSEP=0.1459, DOSC-SPA-BPNN for phosphorus with r=0.7054 and RMSEP=0.0594, and DOSC-SPA-BPNN for potassium with r=0.9380 and RMSEP=0.1788. The prediction precision for nitrogen and potassium determinations was acceptable for further practical applications, whereas further studies are needed to improve the prediction precision for phosphorus. The results indicated that Vis/NIR spectroscopy is feasible for nondestructive determination of nutritional information in oilseed rape leaves. It also provided an alternative technique for detecting other growth information about oilseed rape leaves