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Adverse pregnancy outcomes including prematurity and low birth weight (LBW) have been associated with life-long chronic disease risk for the infant. Stress during pregnancy increases the risk of adverse pregnancy outcomes. Many studies have reported the incidence of adverse pregnancy outcomes in Indigenous populations and a smaller number of studies have measured rates of stress and depression in these populations. This study sought to examine the potential association between stress during pregnancy and the rate of adverse pregnancy outcomes in Australian Indigenous women residing in rural and remote communities in New South Wales. This study found a higher rate of post-traumatic stress disorder, depression and anxiety symptoms during pregnancy than the general population. There was also a higher incidence of prematurity and LBW deliveries. Unfortunately, missing post-traumatic stress disorder and depressive symptomatology data impeded the examination of associations of interest. This was largely due to the highly sensitive nature of the issues under investigation, and the need to ensure adequate levels of trust between Indigenous women and research staff before disclosure and recording of sensitive research data. We were unable to demonstrate a significant association between the level of stress and the incidence of adverse pregnancy outcomes at this stage. We recommend this longitudinal study continue until complete data sets are available. Future research in this area should ensure prioritization of building trust in participants and overestimating sample size to ensure no undue pressure is placed upon an already stressed participant.
Childhood obesity rates are higher among Indigenous compared with non-Indigenous Australian children. It has been hypothesized that early-life influences beginning with the intrauterine environment predict the development of obesity in the offspring. The aim of this paper was to assess, in 227 mother–child dyads from the Gomeroi gaaynggal cohort, associations between prematurity, Gestation Related-Optimal Weight (GROW) centiles, maternal adiposity (percentage body fat, visceral fat area), maternal non-fasting plasma glucose levels (measured at mean gestational age of 23.1 weeks) and offspring BMI and adiposity (abdominal circumference, subscapular skinfold thickness) in early childhood (mean age 23.4 months). Maternal non-fasting plasma glucose concentrations were positively associated with infant birth weight (P=0.005) and GROW customized birth weight centiles (P=0.008). There was a significant association between maternal percentage body fat (P=0.02) and visceral fat area (P=0.00) with infant body weight in early childhood. Body mass index (BMI) in early childhood was significantly higher in offspring born preterm compared with those born at term (P=0.03). GROW customized birth weight centiles was significantly associated with body weight (P=0.01), BMI (P=0.007) and abdominal circumference (P=0.039) at early childhood. Our findings suggest that being born preterm, large for gestational age or exposed to an obesogenic intrauterine environment and higher maternal non-fasting plasma glucose concentrations are associated with increased obesity risk in early childhood. Future strategies should aim to reduce the prevalence of overweight/obesity in women of child-bearing age and emphasize the importance of optimal glycemia during pregnancy, particularly in Indigenous women.
Introduction: Higher levels of anxiety and depression have been found to be associated with greater difficulty in stopping smoking. This raises the question as to whether mood disturbance may be associated with exposure to, and use of, quitting support.
Aims: This study examined whether General Practitioner (GP) advice and/or offer of support, or stop-smoking service use differed between smokers reporting or not reporting depression/anxiety.
Methods: Data came from the Smoking Toolkit Study. Participants were 1,162 English adults who reported currently smoking or having stopped within the past 12 months, aged 40+ years, surveyed between April and September 2012. Anxiety/depression was assessed by the mood disturbance item of the EuroQol five dimensions questionnaire (EQ-5D). This was compared to recall of GP quit advice and/or support, and stop-smoking aid use adjusting for age, gender, and social grade.
Results/Findings: Smokers reporting depression/anxiety were more likely to recall being offered advice and support to stop smoking by their GP (OR = 1.50, 95% C.I. = 1.05–2.13). However, there were no significant differences in use of stop-smoking aids during the past year.
Conclusions: Smokers reporting depression/anxiety are more likely to be offered stop-smoking support by their GPs, but this does not appear to translate into stop-smoking aid use, despite high motivation to quit. Given higher nicotine dependence in this group, mental health specific support may need to be offered, and more needs to be done to make this offer of aid attractive.
In the past, two-dimensional images of internal snow structure have been obtained through plane surface sections or thin sections. These techniques are time-consuming and necessarily destroy the snow specimen. Computed tomography (CT) allows similar images to be obtained, but in a more efficient and non-destructive manner. To demonstrate the methodology, a CT scanner was used to obtain cross-sectional images over time of a snow sample undergoing kinetic-growth metamorphism. Densities calculated from the CT images correlated well to density measured using a traditional method. A procedure was developed that allows the CT image to be converted to binary in an objective manner. Employing innovative stereological software, the microstructural properties (grain diameter, bond diameter, neck length and intercept length) of the snow were then measured from the two-dimensional CT images. The presented methodology provides significant improvements over previous techniques, requiring less time and labor to obtain high-quality microstructural data.
Scattering of radio waves off inhomogeneities in electron density in the interstellar medium can produce an apparent broadening in the angular diameter of an intrinsically compact background radio source. The magnitude and distribution of this effect at low galactic latitudes (|b|<5°) is not well known, although several cases suggest substantial broadening in certain directions, such as the Cygnus X region (Anderson et al. 1972), and the galactic center (Davies, Walsh, and Booth 1976). Large scattering in the plane is consistent with the scintillation properties of pulsars seen through substantial thicknesses (≳ 1 kpc) of the galactic disk.
We discuss the λ6 cm total intensity and polarization structures of a number of BL Lacertae objects at milliarcsecond resolution. 0235+164 was unresolved and weakly polarized at each of two epochs a year apart; each of the other objects displays structure in polarized flux. 0735+178 and 1749+096 can be adequately modeled by two or three point components—a “core” plus one or two “knots.” The core components were moderately polarized (≃ 5%), while “knots” may be polarized at 8% or more, consistent with these components being optically thin. Preliminary results for BL Lac indicate that the total intensity structure can be modeled well by a set of four gaussian components; the polarization structure is complex, but is dominated by the northernmost knot in the jet.
We present a global fringe fitting technique for the polarized fringes in VLBI. The standard search method imposes a signal-to-noise (SNR) limit on usable data. In our method the search procedure is circumvented and the SNR limitation removed.
The λ6 cm milliarcsecond polarization structure of 3C345 has been determined at three epochs between December 1981 and March 1984. The knots C2, C3, and C4 all showed changes as they moved away from the core, which remained virtually unpolarized.
A constitutive theory of snow is developed to describe the mechanical properties of snow in terms of the properties of the ice grains and the necks that interconnect them. The principle of virtual work is used to calculate the stresses in the particles and necks. A number of different deformation mechanisms are investigated and, depending upon the deformation mechanism which is dominant for given load conditions, different equations are used to calculate the strains in the grains and necks. These strains around a representative ice grain are then averaged and scaled to obtain the global strains in the snow. The theory is then compared with experimental data to determine if the mechanical properties of snow can be adequately represented. Results show that the constitutive theory does work, but that it is cumbersome to implement, and that for practical use substantial computational capability is needed.
A continuum theory of mixtures is applied to model snow as a mixture of an elastic solid and an elastic fluid. Three wave types, two dilational and one rotational, are shown to exist. Numerical evaluation shows velocity and attenuation increasing with frequency for all three waves. Wave velocity increases with increasing density while attenuation decreases with increasing density for all three waves. The first dilational wave is associated with the pore fluid, has a slow wave speed and is highly attenuated. This wave exhibits diffusive behavior at low frequencies and nondispersive behavior at high frequencies. The second dilation wave is associated with the solid ice material. It is the fastest of the three wave types and does not appreciably attenuate. Nondispersive wave behavior characterizes this wave at low and high frequencies. The rotational wave occurs only in the solid, is the least attenuated of all three waves, and propagates at velocities greater than that of the first, but less than that of the second, dilational wave. The rotational wave exhibits nondispersive behavior at low and high frequencies. Wave velocities and attenuation show behavior that is in agreement with existing experimental data.
Two–dimensional hydrodynamic equations for laminar, viscous flow, and admitting a frictional slip-plane lower boundary are applied to the modeling of snow-avalanche impact on rigid wall structures. Predicted maximum pressures and pressures versus time are compared with published experimental results, and general correspondence is established. Impact pressure versus time is found to depend upon the shape of the avalanche leading edge, for which general information is lacking. Computer modeling of more complex structural configurations is feasible using the methodology reported.
A set of microstructural variables is selected to characterize the behavior of snow. Corresponding mathematical relations from quantitative stereology theory are presented along with relations and techniques required for numerical evaluation. An experimental investigation is carried out to determine changes in these variables for snow subjected to large compressive deformations. The micro-structural variables studied included coordination number, grain-size, bond radius, neck length, pore-size, free surface area and grains/unit volume. Measurements at several stages of deformation are used to evaluate the changes in the microstructure as functions of deformation. Microstructure measurements of six snow samples subjected to confined compression tests are presented for pre-compressed and compressed states, corresponding to final stresses of 0.387, 0.77 and 1.55 MPa. Grain-size and bond radius were found to go through finite changes during compression, although the variation of bond radius was more complicated in nature. The coordination number and number of bonds/unit volume were found to go through large changes during compression, while specific free surface area was found to increase by 100% due to grain- and bond-fracture processes. No discernible patterns of change in neck length could be found in the experiments. A close relationship between some of the microstructural variables and the stress response of the material was observed. These results serve to contribute to the presently available data and understanding of the microstructural behavior of snow.
We observed 4 planetary transits of HD 209458 with the STIS spectrograph on HST, and generated a photometric time series with extremely rapid cadence and high precision. We use these data to better constrain the orbital, stellar, and planetary parameters, and to search for circumplanetary rings and planetary satellites.
The Millimeter Array, under development in the United States, is a fast and flexible telescope capable of imaging the thermal sky at a resolution equal to that specified in the design goals of the Hubble Space Telescope. The MMA is a project of the U.S. National Science Foundation, and it has been highlighted as one of the four major U.S. initiatives in astronomy for the decade of the 1990s. Construction will begin toward the end of the decade at a site soon to be chosen.