2,956 research outputs found
Positive values of inhomogeneous 5-ary quadratic forms of type (3, 2)
Let Q(x, y, z, t, u) be a real indefinite 5-ary quadratic form of type (3,2) and determinant D(> 0). Then given any real numbers x0, y0, z0, t0, u0 there exist integers x, y, z, t, u such that 0 < Q(x+x0,y+y0,z+z0,t+t0,u+u0)≤(16D)1/5. All the critical forms are also determined
Positive values of inhomogeneous quinary quadratic forms of type (4,1)
Here it is proved that if Q(x, y, z, t, u) is a real indefinite quinary quadratic form of type (4,1) and determinant D, then given any real numbers x0, y0, z0, t0, u0 there exist integers x, y, z, t, u such that 0 < Q(x+x0, y+y0, z+z0, t+t0, u+u0)<|D|1/3
Ramucirumab for Treating Advanced Gastric Cancer or Gastro-Oesophageal Junction Adenocarcinoma Previously Treated with Chemotherapy
The National Institute for Health and Care Excellence (NICE) invited the company that manufactures ramucirumab (Cyramza®, Eli Lilly and Company) to submit evidence of the clinical and cost effectiveness of the drug administered alone (monotherapy) or with paclitaxel (combination therapy) for treating adults with advanced gastric cancer or gastro-oesophageal junction (GC/GOJ) adenocarcinoma that were previously treated with chemotherapy, as part of the Institute’s single technology appraisal (STA) process. Kleijnen Systematic Reviews Ltd (KSR), in collaboration with Erasmus University Rotterdam, was commissioned to act as the Evidence Review Group (ERG). This paper describes the company’s submission, the ERG review, and NICE’s subsequent decisions. Clinical effectiveness evidence for ramucirumab monotherapy (RAM), compared with best supportive care (BSC), was based on data from the REGARD trial. Clinical effectiveness evidence for ramucirumab combination therapy (RAM + PAC), compared with paclitaxel monotherapy (PAC), was based on data from the RAINBOW trial. In addition, the company undertook a network meta-analysis (NMA) to compare RAM + PAC with BSC and docetaxel. Cost-ef
Non-compliance with a postmastectomy radiotherapy guideline: Decision tree and cause analysis
New measurement of via neutron capture on hydrogen at Daya Bay
This article reports an improved independent measurement of neutrino mixing
angle at the Daya Bay Reactor Neutrino Experiment. Electron
antineutrinos were identified by inverse -decays with the emitted
neutron captured by hydrogen, yielding a data-set with principally distinct
uncertainties from that with neutrons captured by gadolinium. With the final
two of eight antineutrino detectors installed, this study used 621 days of data
including the previously reported 217-day data set with six detectors. The
dominant statistical uncertainty was reduced by 49%. Intensive studies of the
cosmogenic muon-induced Li and fast neutron backgrounds and the
neutron-capture energy selection efficiency, resulted in a reduction of the
systematic uncertainty by 26%. The deficit in the detected number of
antineutrinos at the far detectors relative to the expected number based on the
near detectors yielded in the
three-neutrino-oscillation framework. The combination of this result with the
gadolinium-capture result is also reported.Comment: 26 pages, 23 figure
A new measurement of antineutrino oscillation with the full detector configuration at Daya Bay
We report a new measurement of electron antineutrino disappearance using the
fully-constructed Daya Bay Reactor Neutrino Experiment. The final two of eight
antineutrino detectors were installed in the summer of 2012. Including the 404
days of data collected from October 2012 to November 2013 resulted in a total
exposure of 6.910 GW-ton-days, a 3.6 times increase over
our previous results. Improvements in energy calibration limited variations
between detectors to 0.2%. Removal of six Am-C radioactive
calibration sources reduced the background by a factor of two for the detectors
in the experimental hall furthest from the reactors. Direct prediction of the
antineutrino signal in the far detectors based on the measurements in the near
detectors explicitly minimized the dependence of the measurement on models of
reactor antineutrino emission. The uncertainties in our estimates of
and were halved as a result of these
improvements. Analysis of the relative antineutrino rates and energy spectra
between detectors gave and eV in the three-neutrino
framework.Comment: Updated to match final published versio
Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay
The Daya Bay experiment has observed correlations between reactor core fuel
evolution and changes in the reactor antineutrino flux and energy spectrum.
Four antineutrino detectors in two experimental halls were used to identify 2.2
million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles
for each of six 2.9 GW reactor cores at the Daya Bay and Ling
Ao nuclear power plants. Using detector data spanning effective Pu
fission fractions, , from 0.25 to 0.35, Daya Bay measures an average
IBD yield, , of
cm/fission and a fuel-dependent variation in the IBD yield,
, of cm/fission.
This observation rejects the hypothesis of a constant antineutrino flux as a
function of the Pu fission fraction at 10 standard deviations. The
variation in IBD yield was found to be energy-dependent, rejecting the
hypothesis of a constant antineutrino energy spectrum at 5.1 standard
deviations. While measurements of the evolution in the IBD spectrum show
general agreement with predictions from recent reactor models, the measured
evolution in total IBD yield disagrees with recent predictions at 3.1.
This discrepancy indicates that an overall deficit in measured flux with
respect to predictions does not result from equal fractional deficits from the
primary fission isotopes U, Pu, U, and Pu.
Based on measured IBD yield variations, yields of and cm/fission have been determined for the two
dominant fission parent isotopes U and Pu. A 7.8% discrepancy
between the observed and predicted U yield suggests that this isotope
may be the primary contributor to the reactor antineutrino anomaly.Comment: 7 pages, 5 figure
Improved Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay
A new measurement of the reactor antineutrino flux and energy spectrum by the
Daya Bay reactor neutrino experiment is reported. The antineutrinos were
generated by six 2.9~GW nuclear reactors and detected by eight
antineutrino detectors deployed in two near (560~m and 600~m flux-weighted
baselines) and one far (1640~m flux-weighted baseline) underground experimental
halls. With 621 days of data, more than 1.2 million inverse beta decay (IBD)
candidates were detected. The IBD yield in the eight detectors was measured,
and the ratio of measured to predicted flux was found to be
() for the Huber+Mueller (ILL+Vogel) model. A 2.9~
deviation was found in the measured IBD positron energy spectrum compared to
the predictions. In particular, an excess of events in the region of 4-6~MeV
was found in the measured spectrum, with a local significance of 4.4~.
A reactor antineutrino spectrum weighted by the IBD cross section is extracted
for model-independent predictions.Comment: version published in Chinese Physics
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