1,047 research outputs found

    Prevalence of gestational diabetes mellitus in eastern and southeastern Asia: A systematic review and meta-analysis

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    This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Aim. To review the prevalence of gestational diabetes mellitus (GDM) in Eastern and Southeastern Asia. Methods. We systematically searched for observational studies on GDM prevalence from January 2000 to December 2016. Inclusion criteria were original English papers, with full texts published in peer-reviewed journals. The quality of included studies was evaluated using the guidelines of the National Health and Medical Research Council, Australia. Fixed effects and random effects models were used to estimate the summary prevalence of GDM and the corresponding 95% confidence intervals (CI). Results. A total of 4415 papers were screened, and 48 studies with 63 GDM prevalence observations were included in the final review. The pooled prevalence of GDM was 10.1% (95% CI: 6.5%–15.7%), despite substantial variations across nations. The prevalence of GDM in lower- or upper-middle income countries was about 64% higher than in their high-income counterparts. Moreover, the one-step screening method was twice more likely to be used in diagnosing GDM when compared to the two-step screening procedure. Conclusions. The prevalence of GDM in Eastern and Southeastern Asia was high and varied among and within countries. There is a need for international uniformity in screening strategies and diagnostic criteria for GDM

    On the Low Energy Decrease in Galactic Cosmic Ray Secondary/Primary Ratios

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    Galactic cosmic ray (GCR) secondary/primary ratios such as B/C and (Sc+Ti+V)/Fe are commonly used to determine the mean amount of interstellar material through which cosmic rays travel before escaping from the Galaxy (Λ_(esc)). These ratios are observed to be energy-dependent, with a relative maximum at ~1 GeV/nucleon, implying a corresponding peak in Λ_(esc). The decrease in Λ_(esc) at energies above 1 GeV/nucleon is commonly taken to indicate that higher energy cosmic rays escape more easily from the Galaxy. The decrease in Λ_(esc) at energies <1 GeV/nuc is more controversial; suggested possibilities include the effects of a galactic wind or the effects of distributed acceleration of cosmic rays as they pass through the interstellar medium. We consider two possible explanations for the low energy decrease in Λ_(esc) and attempt to fit the combined, high-resolution measurements of secondary/primary ratios from ~0.1 to 35 GeV/nuc made with the CRIS instrument on ACE and the C2 experiment on HEAO-3. The first possibility, which hypothesizes an additional, local component of low-energy cosmic rays that has passed through very little material, is found to have difficulty simultaneously accounting for the abundance of both B and the Fe-secondaries. The second possibility, suggested by Soutoul and Ptuskin, involves a new form for Λ_(esc) motivated by their diffusion-convection model of cosmic rays in the Galaxy. Their suggested form for Λ_(esc)(E) is found to provide an excellent fit to the combined ACE and HEAO data sets

    GCR Neon Isotopic Abundances: Comparison with Wolf-Rayet Star Models and Meteoritic Abundances

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    Measurements of the neon isotopic abundances from the ACE-CRIS experiment are presented. These abundances have been obtained in seven energy intervals over the energy range of ~80≤E≤280 MeV/nucleon. The ^(22)Ne/^(20)Ne source ratio is derived using the measured ^(21)Ne/^(20)Ne abundance as a "tracer" of secondary production of the neon isotopes. We find that the ^(22)Ne/^(20)Ne abundance ratio at the cosmic-ray source is a factor of 5.0±0.2 greater than in the solar wind. The GCR ^(22)Ne/^(20)Ne ratio is also shown to be considerably larger than that found in anomalous cosmic rays, solar energetic particles, most meteoritic samples of matter, and interplanetary dust particles. Recent two-component Wolf-Rayet models provide predictions for the ^(22)Ne/^(20)Ne ratio and other isotope ratios. Comparison of the CRIS neon, iron, and nickel isotopic source abundance ratios with predictions indicate possible enhanced abundances of some neutron-rich nuclides that are expected to accompany the ^(22)Ne excess

    The Phosphorus/Sulfur Abundance Ratio as a Test of Galactic Cosmic-Ray Source Models

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    Galactic cosmic-ray (GCR) elemental abundances display a fractionation compared to solar-system values that appears ordered by atomic properties such as the first ionization potential (FIP) or condensation temperature (volatility). Determining which parameter controls the observed fractionation is crucial to distinguish between GCR origin models. The Cosmic-Ray Isotope Spectrometer (CRIS) instrument on board NASA's Advanced Composition Explorer (ACE) spacecraft can measure the abundances of several elements that break the general correlation between FIP and volatility (e.g., Na, P, K, Cu, Zn, Ga, and Ge). Phosphorus is a particularly interesting case as it is a refractory (high condensation temperature) element with a FIP value nearly identical to that of its semi-volatile neighbor, sulfur. Using a leaky-box galactic propagation model we find that the P/S and Na/Mg ratios in the GCR source favor volatility as the controlling parameter

    Breastfeeding duration in mothers who express breast milk: a cohort study

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    BACKGROUND: The expression of breast milk allows a mother to be away intermittently from her infant while continuing to breastfeed. The aim of this study was to investigate the association between expression of breast milk and breastfeeding duration METHODS: A cohort study of 12 months duration. The mothers were recruited from two public maternity hospitals in Perth, Australia between mid-September 2002 and mid-July 2003. While in hospital, participating mothers completed a questionnaire that included questions on how they were feeding their newborn. Telephone interviews conducted at regular periods monitored changes in infant feeding practices, including expression of breast milk. Multivariate Cox regression analysis was used to explore the association between breast milk expression and the duration of any breastfeeding. RESULTS: A total of 587 mothers, or 55% of those eligible, participated in the study. Of these 93.5% were breastfeeding at discharge from hospital. Mothers who expressed breast milk (at one or more time periods) were less likely to discontinue any breastfeeding before six months (Relative Risk 0.71, 95% CI 0.52, 0.98) than those who had never expressed milk. CONCLUSION: This study found that mothers who express breast milk are more likely to breastfeed to six months (any breastfeeding). While further research is required in different cultures to confirm these results, the appropriate use of expressed breast milk may be a means to help mothers to achieve six months of full breastfeeding while giving more lifestyle options

    Constraints on cosmic-ray acceleration and transport from isotope observations

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    Observations from the Cosmic Ray Isotope Spectrometer (CRIS) on ACE have been used to derive constraints on the locations, physical conditions, and time scales for cosmic-ray acceleration and transport. The isotopic composition of Fe, Co, and Ni is very similar to that of solar system material, indicating that cosmic rays contain contributions from supernovae of both Type II and Type Ia. The electron-capture primary ^(59)Ni produced in supernovae has decayed, demonstrating that a time ≳10^5 yr elapses before acceleration of the bulk of the cosmic rays and showing that most of the accelerated material is derived from old stellar or interstellar material rather than from fresh supernova ejecta

    Measurements of the isotopes of lithium, beryllium, and boron from ACE/CRIS

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    The isotopes of lithium, beryllium, and boron (LiBeB) are known in nature to be produced primarily by CNO spallation and α-α fusion from interactions between cosmic rays and interstellar nuclei. While the dominant source of LiBeB isotopes in the present epoch is cosmic-ray interactions, other sources are known to exist, including the production of ^(7)Li from big bang nucleosynthesis. Precise observations of galactic cosmic-ray LiBeB in addition to accurate modeling of cosmic-ray transport can help to constrain the relative importance among the different production mechanisms. The Cosmic Ray Isotope Spectrometer (CRIS) on the Advanced Composition Explorer (ACE) has measured nuclei with 2 ≲ Z ≲ 30 in the energy range ~30–500 MeV/nucleon since 1997 with good statistical accuracy. We present measurements of the isotopic abundances of LiBeB and discuss these observations in the context of previous cosmic-ray measurements and spectroscopic observations
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