7,738 research outputs found
Community-based incidence of acute renal failure
There is limited information about the true incidence of acute renal failure (ARF). Most studies could not quantify disease frequency in the general population as they are hospital-based and confounded by variations in threshold and the rate of hospitalization. Earlier studies relied on diagnostic codes to identify non-dialysis requiring ARF. These underestimated disease incidence since the codes have low sensitivity. Here we quantified the incidence of non-dialysis and dialysis-requiring ARF among members of a large integrated health care delivery system – Kaiser Permanente of Northern California. Non-dialysis requiring ARF was identified using changes in inpatient serum creatinine values. Between 1996 and 2003, the incidence of non-dialysis requiring ARF increased from 322.7 to 522.4 whereas that of dialysis-requiring ARF increased from 19.5 to 29.5 per 100 000 person-years. ARF was more common in men and among the elderly, although those aged 80 years or more were less likely to receive acute dialysis treatment. We conclude that the use of serum creatinine measurements to identify cases of non-dialysis requiring ARF resulted in much higher estimates of disease incidence compared with previous studies. Both dialysis-requiring and non-dialysis requiring ARFs are becoming more common. Our data underscore the public health importance of ARF
Regularizing effect and local existence for non-cutoff Boltzmann equation
The Boltzmann equation without Grad's angular cutoff assumption is believed
to have regularizing effect on the solution because of the non-integrable
angular singularity of the cross-section. However, even though so far this has
been justified satisfactorily for the spatially homogeneous Boltzmann equation,
it is still basically unsolved for the spatially inhomogeneous Boltzmann
equation. In this paper, by sharpening the coercivity and upper bound estimates
for the collision operator, establishing the hypo-ellipticity of the Boltzmann
operator based on a generalized version of the uncertainty principle, and
analyzing the commutators between the collision operator and some weighted
pseudo differential operators, we prove the regularizing effect in all (time,
space and velocity) variables on solutions when some mild regularity is imposed
on these solutions. For completeness, we also show that when the initial data
has this mild regularity and Maxwellian type decay in velocity variable, there
exists a unique local solution with the same regularity, so that this solution
enjoys the regularity for positive time
Assessing Sustainable Value Creation in Social Enterprises
This research explored how ten social enterprises (SEs) in the Philippines create environmental, economic, and social value in the short and long term. This analysis of sustainable value creation (SVC) was the basis for the development of an assessment tool using the sustainable value framework of Hart and Milstein (2003). The resulting assessment tool, referred to as the SVC-SE Assessment Tool, allows SEs to do a rapid assessment on how they generate environmental, economic, and social effectiveness, efficiency and resilience. A portfolio balance indicates if the SE is creating sustainable value and the resulting scores per aspect and quadrant can help the SE get a sense of performance in the different aspects of SVC. The tool that can give a quick overview of the current SVC of the SE and can also provide assistance in planning for future activities
Sampling constrained probability distributions using Spherical Augmentation
Statistical models with constrained probability distributions are abundant in
machine learning. Some examples include regression models with norm constraints
(e.g., Lasso), probit, many copula models, and latent Dirichlet allocation
(LDA). Bayesian inference involving probability distributions confined to
constrained domains could be quite challenging for commonly used sampling
algorithms. In this paper, we propose a novel augmentation technique that
handles a wide range of constraints by mapping the constrained domain to a
sphere in the augmented space. By moving freely on the surface of this sphere,
sampling algorithms handle constraints implicitly and generate proposals that
remain within boundaries when mapped back to the original space. Our proposed
method, called {Spherical Augmentation}, provides a mathematically natural and
computationally efficient framework for sampling from constrained probability
distributions. We show the advantages of our method over state-of-the-art
sampling algorithms, such as exact Hamiltonian Monte Carlo, using several
examples including truncated Gaussian distributions, Bayesian Lasso, Bayesian
bridge regression, reconstruction of quantized stationary Gaussian process, and
LDA for topic modeling.Comment: 41 pages, 13 figure
Integration of GOCI and AHI Yonsei aerosol optical depth products during the 2016 KORUS-AQ and 2018 EMeRGe campaigns
The Yonsei Aerosol Retrieval (YAER) algorithm for the Geostationary Ocean Color Imager (GOCI) retrieves aerosol optical properties only over dark surfaces, so it is important to mask pixels with bright surfaces. The Advanced Himawari Imager (AHI) is equipped with three shortwave-infrared and nine infrared channels, which is advantageous for bright-pixel masking. In addition, multiple visible and near-infrared channels provide a great advantage in aerosol property retrieval from the AHI and GOCI. By applying the YAER algorithm to 10 min AHI or 1 h GOCI data at 6km x 6km resolution, diurnal variations and aerosol transport can be observed, which has not previously been possible from low-Earth-orbit satellites. This study attempted to estimate the optimal aerosol optical depth (AOD) for East Asia by data fusion, taking into account satellite retrieval uncertainty. The data fusion involved two steps: (1) analysis of error characteristics of each retrieved result with respect to the ground-based Aerosol Robotic Network (AERONET), as well as bias correction based on normalized difference vegetation indexes, and (2) compilation of the fused product using ensemble-mean and maximum-likelihood estimation (MLE) methods. Fused results show a better statistics in terms of fraction within the expected error, correlation coefficient, root-mean-square error (RMSE), and median bias error than the retrieved result for each product. If the RMSE and mean AOD bias values used for MLE fusion are correct, the MLE fused products show better accuracy, but the ensemble-mean products can still be useful as MLE
Structural evolution in the neutron-rich nuclei 106Zr and 108Zr
The low-lying states in 106Zr and 108Zr have been investigated by means of
{\beta}-{\gamma} and isomer spectroscopy at the RI beam factory, respectively.
A new isomer with a half-life of 620\pm150 ns has been identified in 108Zr. For
the sequence of even-even Zr isotopes, the excitation energies of the first 2+
states reach a minimum at N = 64 and gradually increase as the neutron number
increases up to N = 68, suggesting a deformed sub-shell closure at N = 64. The
deformed ground state of 108Zr indicates that a spherical sub-shell gap
predicted at N = 70 is not large enough to change the ground state of 108Zr to
the spherical shape. The possibility of a tetrahedral shape isomer in 108Zr is
also discussed.Comment: 10 pages, 3 figures, Accepted for publication in Phys. Rev. Let
Improved Measurements of Branching Fractions and CP Asymmetries in B-> eta h Decays
We report improved measurements of B decays with an eta meson in the final
state using 492 fb^{-1} of data collected by the Belle detector at the KEKB e^+
e^- collider. We observe the decays B^{+-}-> eta pi^{+-} and B^{+-}-> eta
K^{+-}; the measured branching fractions are Br(B^{+-}-> eta pi^{+-}) = (4.2+-
0.4(stat)+- 0.2(sys))x10^{-6} and Br(B^{+-}-> eta K^{+-}) =
(1.9+-0.3(stat)^{+0.2}_{-0.1}(sys))x10^{-6}. The corresponding CP-violating
asymmetries are measured to be -0.23+- 0.09(stat) +-0.02(sys) for eta pi^{+-}
and -0.39+-0.16(stat)+-0.03(sys) for eta K^{+-}. We also search for B^0-> eta
K^0 decays and set an upper limit of 1.9x10^{-6} at the 90% confidence level.Comment: 7 pages, 3 figure
Evidence for CP Violation in B0 -> D+D- Decays
We report measurements of the branching fraction and CP violation parameters
in B0 -> D+D- decays. The results are based on a data sample that contains 535
x 10^6 BBbar pairs collected at the Upsilon(4S) resonance, with the Belle
detector at the KEKB asymmetric-energy e+e- collider. We obtain [1.97 +- 0.20
(stat) +- 0.20 (syst)] x 10^(-4) for the branching fraction of B0 -> D+D-. The
measured values of the CP violation parameters are: S = -1.13 +- 0.37 +- 0.09,
A = 0.91 +- 0.23 +- 0.06, where the first error is statistical and the second
is systematic. We find evidence of CP violation in B0 -> D+D- at the 4.1 sigma
confidence level. While the value of S is consistent with expectations from
other measurements, the value of the parameter A favors large direct CP
violation at the 3.2 sigma confidence level, in contradiction to Standard Model
expectations.Comment: 12 pages, 3 figures, submitted to PR
Dalitz Analysis of Three-body Charmless B0=>K0pi+pi- Decay
We report results of a Dalitz plot analysis of the three-body charmless
B0=>K0pi+pi- decay. The analysis is performed with a data sample that contains
388 million BBbar pairs collected near the Y(4S) resonance with the Belle
detector at the KEKB asymmetric energy e+e- collider. Measurements of branching
fractions for the quasi-two-body decays B0=>rho(770)0K0, B0=>f0(980)K0,
B0=>K*(892)+pi-, B0=>K*(1430)+pi-, and upper limits on several other
quasi-two-body decay modes are reported.Comment: 9 pages, 5 figures. Submitted to Phys. Rev. Let
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