1,118 research outputs found
Dual-energy X-ray absorptiometry scans accurately predict differing body fat content in live sheep
Background
There is considerable interest in implementing mobile scanning technology for on-farm body composition analysis on live animals. These experiments evaluated the use of dual energy X-ray absorptiometry (DXA) as an accurate method of total body fat measurement in live sheep.
Results
In Exp. 1, visceral and whole body fat analysis was undertaken in sheep with body condition scores (BCS) in the range 2 to 3.25 (scale 1: thin to 5: fat). The relationship of BCS was moderately correlated with visceral fat depot mass (r = 0.59, P 0.05, n = 9). There was a moderate correlation between DXA body fat and BCS (r = 0.70, P < 0.01, n = 17), and DXA body fat was highly correlated with chemical body fat (r = 0.81, P < 0.001, n = 9). In Exp. 3, a series of five DXA scans, at 8-week intervals, was performed on growing sheep over a 32-week period. The average BCS ranged from 2.39 ± 0.07 (S.E.M.) to 3.05 ± 0.11 and the DXA body fat (%) ranged from 16.8 ± 0.8 to 24.2 ± 1.2. There was a moderate correlation between DXA body fat and BCS over the 32 weeks (r = 0.61, P < 0.001, n = 24).
Conclusions
Overall, these experiments indicated that there was good agreement between BCS, DXA and chemical analysis for measuring total body fat in sheep, and that DXA scanning is a valid method for longitudinal measurement of total body fat in live sheep
Support seeking in the postpartum period: content analysis of posts in web-based parenting discussion groups
Background: The transition from pregnancy to motherhood is a major developmental phase that can be challenging for both women and their families. For new mothers, the postpartum period is recognized as a critical period for increased risk of both physical and mental health concerns. For this reason, it is imperative that women receive accurate, evidence-based information during this time. Objective: This study aims to explore the conversations of new mothers on a web-based parenting forum to investigate what topics or concerns are being discussed. Methods: A leading Australian web-based support forum for women before and after birth was used to obtain a sample of posts from the mothers of infants aged 0-12 months. Quantitative data (word frequencies and sentiment analysis) and qualitative data (post content) were extracted from discussion threads and examined to determine sentiments and theoretical storylines. Results: In total, 260 posts were sampled. Infant care was the most prominent overarching topic discussed, with feeding and sleep being the most discussed subtopics. Discussions about maternal care were much less frequent but included questions about birth recovery, breastfeeding concerns, and interconception. A pattern of behavior emerged within the posts. This pattern resembled a cycle of learning across five phases: help seeking, solution ideation, testing and skill development, consolidation, and empowerment and improved mental well-being. A dynamic interplay was observed as mothers navigated new concerns or developmental changes. Conclusions: Engagement in web-based forums to seek help and support during the postpartum period was common, with infant health and well-being being the primary concerns for new mothers during this time. The identification of a maternal learning cycle within the forum underscores the contributory role of web-based communities in maternal peer social support, information seeking, and early parenting practices.Bonnie R Chivers, Rhonda M Garad, Lisa J Moran, Siew Lim, Cheryce L Harriso
Diet quality in a weight gain prevention trial of reproductive aged women: a secondary analysis of a cluster randomized controlled trial
Reproductive-aged women are at high risk for obesity development. Limited research exploring weight gain prevention initiatives and associated modifiable risk factors, including diet quality exists. In a secondary analysis of a 12 month, cluster randomized controlled trial for weight gain prevention in reproductive-aged women, we evaluated change in diet quality, macronutrient and micronutrient intake, predictors of change and associations with weight change at follow-up. Forty-one rural towns in Victoria, Australia were randomized to a healthy lifestyle intervention (n = 21) or control (n = 20). Women aged 18⁻50, of any body mass index and without conditions known to affect weight, were recruited. Diet quality was assessed by the Dietary Guideline Index (DGI) and energy, macronutrient, and micronutrient intake as well as anthropometrics (weight; kg) were measured at baseline and 12 months. Results were adjusted for group (intervention/control), town cluster, and baseline values of interest. Of 409 women with matched data at baseline and follow-up, 220 women were included for final analysis after accounting for plausible energy intake. At 12 months, diet quality had improved by 6.2% following the intervention, compared to no change observed in the controls (p < 0.001). Significant association was found between a change in weight and a change in diet quality score over time β -0.66 (95%CI -1.2, -0.12) p = 0.02. The percentage of energy from protein (%) 0.009 (95%CI 0.002, 0.15) p = 0.01 and glycemic index -1.2 (95%CI -2.1, -0.24) p = 0.02 were also improved following the intervention, compared to the control group. Overall, a low-intensity lifestyle intervention effectively improves diet quality, with associated weight gain preventions, in women of reproductive age.Julie C. Martin, Lisa J. Moran, Helena J. Teede, Sanjeeva Ranasinha, Catherine B. Lombard and Cheryce L. Harriso
Postpartum diet quality: a cross-sectional analysis from the Australian Longitudinal Study on Women's Health
Reproductive-aged women are at high risk of developing obesity, and diet quality is a potential modifiable risk factor. There is limited research exploring diet quality and its association with time since childbirth. Using data from the Australian Longitudinal Study on Women's Health (ALSWH) survey 5 (2009) of women born between 1973-1978, who reported having previously given birth, we investigated the association between time since childbirth and diet quality, and differences in energy, macronutrients, micronutrient intake, and diet quality assessed by the dietary guideline index (DGI) in women stratified by time from last childbirth, early (0-6 months; n = 558) and late (7-12 months; n = 547), and all other women with children (>12 months post childbirth n = 3434). From this cohort, 8200 participants were eligible, of which 4539 participants completed a food frequency questionnaire (FFQ) and were included in this analysis. Overall, diet quality was higher in early and late postpartum women (mean DGI score 89.8 (SD 10.5) and mean DGI score 90.0 (SD 10.2), respectively) compared to all other women with children (>12 months post childbirth), mean DGI score 85.2 (SD 11.7), p 12 months), smoking compared with non-smoking and medium income level compared with no income was negatively associated with diet quality. A lower diet quality in women greater than 12 months post childbirth may be reflective of increased pressures, balancing childrearing and return to work responsibilities. This highlights the need to support women beyond the postpartum period to improve modifiable factors associated with weight gain, including diet quality, to optimize health and reduce chronic disease risk.Julie C. Martin, Anju E. Joham, Gita D. Mishra, Allison M. Hodge, Lisa J. Moran, and Cheryce L. Harriso
Dynamics of systems with isotropic competing interactions in an external field: a Langevin approach
We study the Langevin dynamics of a ferromagnetic Ginzburg-Landau Hamiltonian
with a competing long-range repulsive term in the presence of an external
magnetic field. The model is analytically solved within the self consistent
Hartree approximation for two different initial conditions: disordered or zero
field cooled (ZFC), and fully magnetized or field cooled (FC). To test the
predictions of the approximation we develop a suitable numerical scheme to
ensure the isotropic nature of the interactions. Both the analytical approach
and the numerical simulations of two-dimensional finite systems confirm a
simple aging scenario at zero temperature and zero field. At zero temperature a
critical field is found below which the initial conditions are relevant
for the long time dynamics of the system. For a logarithmic growth of
modulated domains is found in the numerical simulations but this behavior is
not captured by the analytical approach which predicts a growth law at
Alteration layer formation of Ca- and Zn-oxide bearing alkali borosilicate glasses for immobilisation of UK high level waste: A vapour hydration study
The UK high level nuclear waste glass modified with CaO/ZnO was investigated using the vapour phase hydration test, performed at 200 °C, with the aim of understanding the impact of the modification on the chemical composition and microstructure of the alteration layer. Experiments were undertaken on non-modified and CaO/ZnO-modified base glass, with or without 25 wt% of simulant Magnox waste calcine. The modification resulted in a dramatic reduction in gel layer thickness and also a reduction in the reaction rate, from 3.4 ± 0.3 g m−2 d−1 without CaO/ZnO modification to 0.9 ± 0.1 g m−2 d−1 with CaO/ZnO. The precipitated phase assemblage for the CaO/ZnO-modified compositions was identified as hydrated Ca- and Zn-bearing silicate phases, which were absent from the non-modified counterpart. These results are in agreement with other recent studies showing the beneficial effects of ZnO additions on glass durability
Chemokine-guided angiogenesis directs coronary vasculature formation in zebrafish.
Supramolecular & Biomaterials Chemistr
Top-squark searches at the Tevatron in models of low-energy supersymmetry breaking
We study the production and decays of top squarks (stops) at the Tevatron
collider in models of low-energy supersymmetry breaking. We consider the case
where the lightest Standard Model (SM) superpartner is a light neutralino that
predominantly decays into a photon and a light gravitino. Considering the
lighter stop to be the next-to-lightest Standard Model superpartner, we analyze
stop signatures associated with jets, photons and missing energy, which lead to
signals naturally larger than the associated SM backgrounds. We consider both
2-body and 3-body decays of the top squarks and show that the reach of the
Tevatron can be significantly larger than that expected within either the
standard supergravity models or models of low-energy supersymmetry breaking in
which the stop is the lightest SM superpartner. For a modest projection of the
final Tevatron luminosity, L = 4 fb-1, stop masses of order 300 GeV are
accessible at the Tevatron collider in both 2-body and 3-body decay modes. We
also consider the production and decay of ten degenerate squarks that are the
supersymmetric partners of the five light quarks. In this case we find that
common squark masses up to 360 GeV are easily accessible at the Tevatron
collider, and that the reach increases further if the gluino is light.Comment: 32 pages, 9 figures; references adde
Association between pregnancy intention and psychological distress among women exposed to different levels of restrictions during the COVID-19 pandemic in Australia.
Background The COVID-19 pandemic has had a negative impact on the mental health of people globally. Significant concerns about health and access to services among women of reproductive age considering pregnancy may cause psychological distress, and in turn increase health risks during and after pregnancy for mothers and offspring. Objectives To examine the association between pregnancy intention and psychological distress during the COVID-19 pandemic in Australia, and explore if this association differed based on local viral transmission rates and corresponding levels of pandemic restrictions. Methods A nationwide online survey was completed by 849 non-pregnant women aged 18–50 years between 15 October and 7 November 2020. Women were asked about their intention to become pregnant, and psychological distress was assessed using the Kessler Psychological Distress Scale (K10). Multivariable regression analysis examined associations between pregnancy intention and psychological distress. An interaction term was added to the model to examine differences in associations by level of viral transmission rates and lockdown restrictions which was determined based on postcode. Results Pregnancy intention was not associated with experiencing (very) high psychological distress in the overall study population (odds ratio (OR) 1.42, 95% CI 0.94, 2.11). The interaction term (p = 0.09) suggested potential differences by level of restrictions and viral transmission rates. In stratified analysis among women living in a location with strict lockdown restrictions and high viral transmission rates leading up to and during the study, those planning to become pregnant were more likely to experience (very) high psychological distress (OR 3.39, 2.04, 5.65) compared with women not planning to become pregnant. Pregnancy intention was not associated with psychological distress among women exposed to lower levels of pandemic restrictions and viral transmission rates (OR 1.17, 0.74, 1.85). Conclusions Our findings highlight the need to identify and support women planning pregnancy during a public health crisis to mitigate potential short- and long-term intergenerational negative health outcomes associated with psychological distress.Danielle A. J. M. Schoenaker, Christie Bennett, Jessica A. Grieger, Cheryce L. Harrison, Briony Hill, Joanne Enticott, Lisa J. Moran, Helena J. Teede, Sharleen L. O, Reilly, Siew Li
Physical and optical properties of the International Simple Glass
Radioactive waste immobilization is a means to limit the release of radionuclides from various waste streams into the environment over a timescale of hundreds to many thousands of years. Incorporation of radionuclide-containing wastes into borosilicate glass during vitrification is one potential route to accomplish such immobilization. To facilitate comparisons and assessments of reproducibility across experiments and laboratories, a six-component borosilicate glass (Si, B, Na, Al, Ca, Zr) known as the International Simple Glass (ISG) was developed by international consensus as a compromise between simplicity and similarity to waste glasses. Focusing on a single glass composition with a multi-pronged approach utilizing state-of-the-art, multi-scale experimental and theoretical tools provides a common database that can be used to assess relative importance of mechanisms and models. Here we present physical property data (both published and previously unpublished) on a single batch of ISG, which was cast into individual ingots that were distributed to the collaborators. Properties from the atomic scale to the macroscale, including composition and elemental impurities, phase purity, density, thermal properties, mechanical properties, optical and vibrational properties, and the results of molecular dynamics simulations are presented. In addition, information on the surface composition and morphology after polishing is included. Although the existing literature on the alteration of ISG is not extensively reviewed here, the results of well-controlled static alteration experiments are presented here as a point of reference for other performance investigations
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