Summary
In this large longitudinal study of 16,078 Korean men aged 50 years or older, we observed that baseline elevation of serum uric acid level significantly associated with a lower risk of ...incident fractures at osteoporosis-related sites during an average follow-up period of 3 years.
Introduction
Male osteoporosis and related fractures are becoming recognized as important public health concerns. Oxidative stress has detrimental effects on bone metabolism, and serum uric acid (UA) is known to be a strong endogenous antioxidant. In the present study, we performed a large longitudinal study with an average follow-up period of 3 years to clarify the role of UA on the risk of incident osteoporotic fractures (OFs).
Methods
A total of 16,078 Korean men aged 50 years or older who had undergone comprehensive routine health examinations were enrolled. Incident fractures at osteoporosis-related sites (e.g., hip, spine, distal radius, and proximal humerus) that occurred after the baseline examinations were identified from the nationwide claims database of the Health Insurance Review and Assessment Service of Korea by using selected International Classification of Diseases, 10th revision codes.
Results
In total, 158 (1.0 %) men developed incident OFs. The event rate was 33.1 per 10,000 person-years. Subjects without incident OFs had 6.0 % higher serum UA levels than subjects with OFs (
P
= 0.001). Multivariable-adjusted Cox proportional hazard analyses adjusted for age, body mass index, glomerular filtration rate, lifestyle factors, medical and drug histories, and the presence of baseline radiological vertebral fractures revealed that the hazard ratio per standard deviation increase of baseline UA levels for the development of incident OFs was 0.829 (95 % CI = 0.695–0.989,
P
= 0.038).
Conclusions
These data provide the epidemiological evidence that serum UA may act as a protective factor against the development of incident OFs in Korean men.
Gamma-rays and fast and thermal neutron attenuation features of (Bi
2
O
3
)
x
–(TeO
2
)
(100−
x
)
(where
x
= 5, 8, 10, 12, and 15 mol%) and (TeO
2
)
0.7
–(B
2
O
3
)
0.3
(1−
x
)
–(Bi
2
O
3
)
x
...(where
x
= 0.05, 0.10, 0,15, 0.20, 0.25, and 0.3 mol%) glass systems have been explored and compared. For all samples, mass attenuation coefficients (
μ
/
ρ
) are estimated within 0.015–15 MeV photon energy range by MCNP5 simulation code and correlated with WinXCom results, which showed a satisfactory agreement between computed
μ
/
ρ
values by these both methods. Additionally, effective atomic number (
Z
eff
), effective electron density (
N
eff
), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), total atomic cross-section (
σ
a
), and total electronic cross-section (
σ
e
) are calculated by utilizing
μ
/
ρ
values. The
μ
/
ρ
,
Z
eff
, and
N
eff
are energy dependent and have higher values at the lowest energy and smaller values at higher energies. Moreover, using the G–P fitting method as a function of penetration depth (up to 40 mfp) and incident photon energy (0.015–15 MeV range), exposure buildup factors (EBFs) and energy absorption buildup factors (EABFs) are evaluated. Both 85TeO
2
–15Bi
2
O
3
(mol%) and 49TeO
2
–21B
2
O
3
–30Bi
2
O
3
(mol%) samples, by possessing higher values of
Z
eff
, exhibit minimum EBF and EABF values. Highest
μ
/
ρ
,
Z
eff
values and lowest HVL, TVL, MFP values of 49TeO
2
–21B
2
O
3
–30Bi
2
O
3
(mol%) sample indicated its better gamma-ray absorption capability among all selected glasses. Further, macroscopic effective removal cross-section for fast neutrons (Σ
R
), coherent scattering cross-section (
σ
cs
), incoherent scattering cross-section (
σ
ics
), absorption cross-section (
σ
A
), and total cross-section (
σ
T
) values for thermal neutron attenuation have been computed. Among all samples, 49TeO
2
–21B
2
O
3
–30Bi
2
O
3
(mol%) glass possesses a better Σ
R
value for fast neutron attenuation, while the largest ‘
σ
T
’ value of 66.5TeO
2
–28.5B
2
O
3
–5Bi
2
O
3
(mol%) sample suggests its good thermal neutron absorption efficiency.
ABSTRACT
We introduce the southern stellar stream spectroscopy survey (S5), an on-going program to map the kinematics and chemistry of stellar streams in the southern hemisphere. The initial focus of ...S5 has been spectroscopic observations of recently identified streams within the footprint of the dark energy survey (DES), with the eventual goal of surveying streams across the entire southern sky. Stellar streams are composed of material that has been tidally striped from dwarf galaxies and globular clusters and hence are excellent dynamical probes of the gravitational potential of the Milky Way, as well as providing a detailed snapshot of its accretion history. Observing with the 3.9 m Anglo-Australian Telescope’s 2-degree-Field fibre positioner and AAOmega spectrograph, and combining the precise photometry of DES DR1 with the superb proper motions from Gaia DR2, allows us to conduct an efficient spectroscopic survey to map these stellar streams. So far S5 has mapped nine DES streams and three streams outside of DES; the former are the first spectroscopic observations of these recently discovered streams. In addition to the stream survey, we use spare fibres to undertake a Milky Way halo survey and a low-redshift galaxy survey. This paper presents an overview of the S5 program, describing the scientific motivation for the survey, target selection, observation strategy, data reduction, and survey validation. Finally, we describe early science results on stellar streams and Milky Way halo stars drawn from the survey. Updates on S5, including future public data releases, can be found at http://s5collab.github.io.
Abstract
A large fraction of gamma-ray burst (GRB) lightcurves (LCs) show X-ray plateaus. We analyze all GRBs with known redshifts presenting plateaus observed by The Neil Gehrels Swift Observatory ...from its launch until 2019 August. The fundamental plane relation between the rest-frame time and X-ray luminosity at the end of the plateau emission and the peak prompt luminosity holds for all the GRB classes when selection biases and cosmological evolutions are applied. We have discovered two important findings: (1) a new class of long GRBs with good data coverage: the platinum sample; and (2) the platinum, the SNe-LGRB, and the KN-SGRB samples, yield the smallest intrinsic scatter with
σ
platinum
,
GRB−SNe
= 0.22 ± 0.10 and
σ
KN−SGRB
= 0.24 ± 0.12. The SNe-LGRBs are composed of GRBs associated spectroscopically with the SNe Ib,c, the KN-SGRBs are composed by eight GRBs associated with kilonovae or where there could have been such an association. The highest correlation coefficients are yielded for the SN-LGRB-ABC sample, which includes GRBs spectroscopically associated with SNe Ib/c or with a clear optical bump in the LC resembling the SNe Ib/c, (
), the SN-LGRBs (
), and the KN-SGRBs (
) when the redshift evolution is considered. These category planes are reliable candidates to use as cosmological tools. Furthermore, the distance from the gold fundamental plane is a crucial discriminant among classes. In fact, we find that the distributions of the distances of the SNe-LGRB, SNe-LGRB-ABC, KN-SGRB, and SGRB samples from the gold fundamental plane are statistically different from the distribution of the gold GRBs’ distances from the gold fundamental plane with and without considering evolution cases.
A microstructure-based integrated crystal plasticity (CP) and continuum damage mechanics (CDM) model is proposed for simulating rolling contact fatigue (RCF). The damage process through the formation ...of the dark etching region (DER) under RCF is implemented, i.e., a DER-CPCDM approach. A hierarchical microstructure of lath martensite is virtually generated by the Voronoi tessellation technique and the theoretical Kurdjumov-Sachs orientation relationship between the prior austenite grains and substructures of lath martensite. Moreover, the micro-plasticity calculated from the polycrystal finite element is coupled with dislocation-assisted carbon migration theory, which enables accurate predictions of the deformation inhomogeneity and the DER/damage distribution at the subsurface. The RCF lifespan of AISI 52100 bearing steel can be predicted within reasonable accuracy, in terms of Weibull probability analysis, when the jump-in-cycles approach is implemented in the DER-CPCDM model. The predicted representative lifespan of the Weibull plot is within an error of 13% when compared with reported experimental data. Process factors, including contact pressure, rotational speed, temperature, carbon concentration, and grain size, are analyzed in a numerical sensitivity study, which can be utilized for potential optimization of the RCF process for improving the performance of materials and parts.
Display omitted
•An integrated model coupling microstructure-based crystal plasticity and continuum damage mechanics is developed.•Microstructure evolution through dislocation assisted carbon migration, or dark etching region, can be modeled.•Hierarchical martensitic microstructure can be implemented through RVE and Kurdjumov-Sachs relation.•The integrated computational model accurately predicts the lifespan of rolling contact fatigue of steel.
Raman or Brillouin amplification of a laser beam in plasma has long been seen as a way to reach multi-PW powers in compact laser systems. However, no significant plasma-based Raman amplification of a ...laser pulse beyond 0.1 TW has been achieved in nearly 20 years, and only one report of Brillouin amplification beyond 1 TW. In this paper, we reveal novel non-linear criteria for the initial seed pulse that will finally open the door to efficient Raman and Brillouin amplification to petawatt powers and Joule-level energies. We show that the triple product of the coupling constant Formula: see text, seed pulse duration Formula: see text and seed pulse amplitude a for the Raman seed pulse (or Formula: see text for Brillouin) must exceed a specific minimum threshold for efficient amplification. We also analyze the plasma-based Raman and Brillouin amplification experiments to date, and show that the seed pulses used in nearly all experiments are well below our new threshold, which explains the poor efficiency obtained in them. Finally, we analyze a recent Brillouin amplification experiment that used increased seed pulse power to obtain Joule-level amplification, and find excellent agreement with our theory.
The Dark Energy Survey Image Processing Pipeline Morganson, E.; Gruendl, R. A.; Menanteau, F. ...
Publications of the Astronomical Society of the Pacific,
07/2018, Volume:
130, Issue:
989
Journal Article
Peer reviewed
Open access
The Dark Energy Survey (DES) is a five-year optical imaging campaign with the goal of understanding the origin of cosmic acceleration. DES performs a ∼5000 deg2 survey of the southern sky in five ...optical bands (g, r, i, z, Y) to a depth of ∼24th magnitude. Contemporaneously, DES performs a deep, time-domain survey in four optical bands (g, r, i, z) over ∼27 deg2. DES exposures are processed nightly with an evolving data reduction pipeline and evaluated for image quality to determine if they need to be retaken. Difference imaging and transient source detection are also performed in the time domain component nightly. On a bi-annual basis, DES exposures are reprocessed with a refined pipeline and coadded to maximize imaging depth. Here we describe the DES image processing pipeline in support of DES science, as a reference for users of archival DES data, and as a guide for future astronomical surveys.
Cosmic-ray proton and helium spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass experiment flown for 42 days in Antarctica in the 2004-2005 austral summer season. ...High-energy cosmic-ray data were collected at an average altitude of ~38.5 km with an average atmospheric overburden of ~3.9 g cm--2. Individual elements are clearly separated with a charge resolution of ~0.15 e (in charge units) and ~0.2 e for protons and helium nuclei, respectively. The measured spectra at the top of the atmosphere are represented by power laws with a spectral index of --2.66 ? 0.02 for protons from 2.5 TeV to 250 TeV and --2.58 ? 0.02 for helium nuclei from 630 GeV nucleon--1 to 63 TeV nucleon--1. They are harder than previous measurements at a few tens of GeV nucleon--1. The helium flux is higher than that expected from the extrapolation of the power law fitted to the lower-energy data. The relative abundance of protons to helium nuclei is 9.1 ? 0.5 for the range from 2.5 TeV nucleon--1 to 63 TeV nucleon--1. This ratio is considerably smaller than the previous measurements at a few tens of GeV nucleon--1.
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