2,583 research outputs found
A Unified Approach to the Classical Statistical Analysis of Small Signals
We give a classical confidence belt construction which unifies the treatment
of upper confidence limits for null results and two-sided confidence intervals
for non-null results. The unified treatment solves a problem (apparently not
previously recognized) that the choice of upper limit or two-sided intervals
leads to intervals which are not confidence intervals if the choice is based on
the data. We apply the construction to two related problems which have recently
been a battle-ground between classical and Bayesian statistics: Poisson
processes with background, and Gaussian errors with a bounded physical region.
In contrast with the usual classical construction for upper limits, our
construction avoids unphysical confidence intervals. In contrast with some
popular Bayesian intervals, our intervals eliminate conservatism (frequentist
coverage greater than the stated confidence) in the Gaussian case and reduce it
to a level dictated by discreteness in the Poisson case. We generalize the
method in order to apply it to analysis of experiments searching for neutrino
oscillations. We show that this technique both gives correct coverage and is
powerful, while other classical techniques that have been used by neutrino
oscillation search experiments fail one or both of these criteria.Comment: 40 pages, 15 figures. Changes 15-Dec-99 to agree more closely with
published version. A few small changes, plus the two substantive changes we
made in proof back in 1998: 1) The definition of "sensitivity" in Sec. V(C).
It was inconsistent with our actual definition in Sec. VI. 2) "Note added in
proof" at end of the Conclusio
Evidence for at center-of-mass energies from 4.009 to 4.360 GeV
Using data samples collected at center-of-mass energies of =
4.009, 4.230, 4.260, and 4.360 GeV with the BESIII detector operating at the
BEPCII collider, we perform a search for the process
and find evidence for and
with statistical significances of 3.0 and
3.4, respectively. The Born cross sections
, as well as their upper limits at the
90% confidence level are determined at each center-of-mass energy.Comment: 8 pages, 7 figures, 3 table
Observation of decays into vector meson pairs , , and
Decays of to vector meson pairs , and
are observed for the first time using
\psip events accumulated at the BESIII detector at the BEPCII
collider. The branching fractions are measured to be , , and , for , , and ,
respectively. The observation of decays into a pair of vector
mesons , and indicates that the hadron
helicity selection rule is significantly violated in decays. In
addition, the measurement of gives the rate of doubly
OZI-suppressed decay. Branching fractions for and
decays into other vector meson pairs are also measured with improved precision.Comment: 4 pages, 2 figure
Improved measurement of the absolute branching fraction of
By analyzing 2.93 fb of data collected at GeV with the
BESIII detector, we measure the absolute branching fraction , which is consistent with previous measurements within
uncertainties but with significantly improved precision. Combining the Particle
Data Group values of , , and the lifetimes of the and
mesons with the value of measured in this work, we determine the following ratios of
partial widths: and .Comment: 9 pages; 8 figure
Detection of SARS-associated Coronavirus in Throat Wash and Saliva in Early Diagnosis
Early detection of SARS-CoV in throat wash and saliva suggests that these specimens are ideal for SARS diagnosis
Guidelines for burn rehabilitation in China
Abstract
Quality of life and functional recovery after burn injury is the final goal of burn care, especially as most of burn patients survive the injury due to advanced medical science. However, dysfunction, disfigurement, contractures, psychological problems and other discomforts due to burns and the consequent scars are common, and physical therapy and occupational therapy provide alternative treatments for these problems of burn patients. This guideline, organized by the Chinese Burn Association and Chinese Association of Burn Surgeons aims to emphasize the importance of team work in burn care and provide a brief introduction of the outlines of physical and occupational therapies during burn treatment, which is suitable for the current medical circumstances of China. It can be used as the start of the tools for burn rehabilitation.</jats:p
Regional variation in the role of humidity on city-level heat-related mortality
The rising humid heat is regarded as a severe threat to human survivability, but the proper integration of humid heat into heat-health alerts is still being explored. Using state-of-the-art epidemiological and climatological datasets, we examined the association between multiple heat stress indicators (HSIs) and daily human mortality in 739 cities worldwide. Notable differences were observed in the long-term trends and timing of heat events detected by HSIs. Air temperature (Tair) predicts heat-related mortality well in cities with a robust negative Tair-relative humidity correlation (CT-RH). However, in cities with near-zero or weak positive CT-RH, HSIs considering humidity provide enhanced predictive power compared to Tair. Furthermore, the magnitude and timing of heat-related mortality measured by HSIs could differ largely from those associated with Tair in many cities. Our findings provide important insights into specific regions where humans are vulnerable to humid heat and can facilitate the further enhancement of heat-health alert systems
Sex-related differences in presentation, treatment, and outcomes of Asian patients with atrial fibrillation: a report from the prospective APHRS-AF Registry
We aimed to investigate the sex-related differences in the clinical course of patients with Atrial Fibrillation (AF) enrolled in the Asia–Pacific-Heart-Rhythm-Society Registry. Logistic regression was utilized to investigate the relationship between sex and oral anticoagulant, rhythm control strategies and the 1-year chance to maintain sinus rhythm. Cox-regression was utilized to assess the 1-year risk of all-cause, and cardiovascular death, thromboembolic events, acute coronary syndrome, heart failure, and major bleeding. In the whole cohort (4121 patients, 69 ± 12 years,34.3% female), females had different cardiovascular risk factors, clinical manifestations, and disease perceptions than men, with more advanced age (72 ± 11 vs 67 ± 12 years, p < 0.001) and dyslipidemia (36.7% vs 41.7%, p = 0.002). Coronary artery disease was more prevalent in males (21.1% vs 16.1%, p < 0.001) as well as the use of antiplatelet drugs. Females had a higher use of oral anticoagulant (84.9% vs 81.3%, p = 0.004) but this difference was non-significant after adjustment for confounders. On multivariable analyses, females were less often treated with rhythm control strategies (Odds Ratio [OR] 0.44,95% Confidence Interval [CI] 0.38–0.51) and were less likely to maintain sinus rhythm (OR 0.27, 95% CI 0.22–0.34) compared to males. Cox-regressions analysis showed no sex-related differences for the risk of death, cardiovascular, and bleeding. The clinical management of Asian AF patients should consider several sex-related differences
Observation of Electromagnetic Dalitz decays J/\psi \to P e^+e^-
Based on a sample of (225.3\pm2.8)\times 10^{6} J/\psi events collected with
the BESIII detector, the electromagnetic Dalitz decays of J/\psi \to P
e^+e^-(P=\eta'/\eta/\pi^0) are studied. By reconstructing the pseudoscalar
mesons in various decay modes, the decays J/\psi \to \eta' e^+e^-, J/\psi \to
\eta e^+e^- and J/\psi \to \pi^0 e^+e^- are observed for the first time. The
branching fractions are determined to be \mathcal{B}(J/\psi\to \eta' e^+e^-) =
(5.81\pm0.16\pm0.31)\times10^{-5}, \mathcal{B}(J/\psi\to \eta e^+e^-) =
(1.16\pm0.07\pm0.06)\times10^{-5}, and \mathcal{B}(J/\psi\to \pi^0
e^+e^-)=(7.56\pm1.32\pm0.50)\times10^{-7}, where the first errors are
statistical and the second ones systematic
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