475 research outputs found
Sexual Dimorphism in Adverse Pregnancy Outcomes - A Retrospective Australian Population Study 1981-2011
Objectives Sexual inequality starts in utero. The contribution of biological sex to the developmental origins of health and disease is increasingly recognized. The aim of this study was to assess and interpret sexual dimorphisms for three major adverse pregnancy outcomes which affect the health of the neonate, child and potentially adult. Methods Retrospective population-based study of 574,358 South Australian singleton live births during 1981-2011. The incidence of three major adverse pregnancy outcomes [preterm birth (PTB), pregnancy induced hypertensive disorders (PIHD) and gestational diabetes mellitus (GDM)] in relation to fetal sex was compared according to traditional and fetus-at-risk (FAR) approaches. Results The traditional approach showed male predominance for PTB [20-24 weeks: Relative Risk (RR) M/F 1.351, 95%-CI 1.274-1.445], spontaneous PTB [25-29 weeks: RR M/F 1.118, 95%-CI 1.044-1.197%], GDM [RR M/F 1.042, 95%-CI 1.011-1.074], overall PIHD [RR M/F 1.053, 95%-CI 1.034-1.072] and PIHD with term birth [RR M/F 1.074, 95%-CI 1.044-1.105]. The FAR approach showed that males were at increased risk for PTB [20-24 weeks: RR M/F 1.273, 95%-CI 1.087-1.490], for spontaneous PTB [25-29 weeks: RR M/F 1.269, 95%-CI 1.143-1.410] and PIHD with term birth [RR M/F 1.074, 95%-CI 1.044-1.105%]. The traditional approach demonstrated female predominance for iatrogenic PTB [25-29 weeks: RR M/F 0.857, 95%-CI 0.780-0.941] and PIHD associated with PTB [25-29 weeks: RR M/F 0.686, 95%-CI 0.581-0.811]. The FAR approach showed that females were at increased risk for PIHD with PTB [25-29 weeks: RR M/F 0.779, 95%-CI 0.648-0.937]. Conclusions This study confirms the presence of sexual dimorphisms and presents a coherent framework based on two analytical approaches to assess and interpret the sexual dimorphisms for major adverse pregnancy outcomes. The mechanisms by which these occur remain elusive, but sex differences in placental gene expression and function are likely to play a key role. Further research on sex differences in placental function and maternal adaptation to pregnancy is required to delineate the causal molecular mechanisms in sex-specific pregnancy outcome. Identifying these mechanisms may inform fetal sex specific tailored antenatal and neonatal care
Seasonality of gestational diabetes mellitus:a South Australian population study
Objective: To investigate whether there is a seasonal variation in the incidence of gestational diabetes mellitus (GDM). Research design and methods: This retrospective cohort study of 60 306 eligible South Australian live-born singletons during 2007-2011 recorded in the South Australian Perinatal Statistics Collection (SAPSC) examined the incidence of GDM in relation to estimated date of conception (eDoC). Fourier series analysis was used to model seasonal trends. Results: During the study period, 3632 (6.0%) women were diagnosed with GDM. Seasonal modeling showed a strong relation between GDM and eDoC (p Conclusions: This study is the first population-based study to demonstrate a seasonal variation for GDM. Several maternal lifestyle and psychosocial factors associated with seasonality and GDM may be influential in the pathophysiologic mechanisms of GDM. Ambient temperature, physical activity, nutrient intake, and vitamin D levels may affect maternal physiology, and fetal and placental development at the cellular level and contribute to the development of GDM. The mechanisms underlying these possible associations are not fully understood and warrant further investigation
Templateâ Directed Solidification of Eutectic Optical Materials
Mesostructured materials can exhibit enhanced lightâ matter interactions, which can become particularly strong when the characteristic dimensions of the structure are similar to or smaller than the wavelength of light. For controlling visible to nearâ infrared wavelengths, the small characteristic dimensions of the required structures usually demand fabrication by sophisticated lithographic techniques. However, these fabrication methods are restricted to producing 2D and a limited range of 3D structures. When a large volume of structured material is required, the primary approach is to use selfâ assembly, and the literature includes many examples of mesostructured optical materials formed via selfâ assembly. However, selfâ organized materials almost always contain structural imperfections which limit their performance. Emerging work, however, is showing that by performing selfâ assembly within a guiding template, the defect density in selfâ assembled structures can be reduced. Particularly interesting is the possibility that utilizing a template can result in the formation of mesostructures not present in either the template or the native selfâ organizing material. In this review, particular emphasis is placed on emerging results showing the effect of mesoscale templates on the microstructure of solidifying eutectic materials, with a specific focus on how templateâ directed solidification may be a powerful approach for fabricating optically active structures, including optical metamaterials.Templateâ directed assembly gives access to structures that are not present in either the template or the native selfâ organizing material. Proofâ ofâ concept works on templateâ directed selfâ organization of solidifying eutectic materials have exhibited intriguing results for photonics and optical metamaterials. This article provides a review of the challenges and opportunities of this technique for forming optically powerful structures.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144275/1/adom201800071_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144275/2/adom201800071.pd
Observation of isotropic giant magnetoresistance in paramagnetic Au80 Fe20
Magnetization and magnetoresistance were measured at room temperature and above on Au80Fe20 platelets and ribbons obtained by solid-state quenching and melt spinning. The as-quenched samples contain a solid solution of Fe in Au and exhibit a paramagnetic (Curie-Weiss) behavior in the considered temperature range; magnetic data indicate very short-ranged magnetic correlation among adjacent spins, enhanced by local composition fluctuations. The solid solution is very stable. Only a very limited fraction (never exceeding 1%) of nanometer-sized, bcc Fe particles appears after long-time isothermal anneals at suitable temperatures. A negative magnetoresistance was observed at room temperature in all examined samples. The observed effect is anhysteretic, isotropic, and quadratically dependent on magnetic field H and magnetization M. The signal scales with M rather than with H, indicating that it depends on the field-induced magnetic order of the Fe moments, as it does for conventional giant magnetoresistance in granular magnetic systems. This effect derives from spin-dependent scattering of conduction electrons from single Fe spins or very small Fe clusters. The scattering centers are almost uncorrelated at a distance of the order of the electronic mean free path (of the order of 1.5 nm, or a few atomic spacings, at RT
A single intravenous reelin injection restores corticosterone-induced neurochemical and behavioral alterations in dams during the post-partum period
IntroductionTreatment with the synaptic plasticity protein reelin has rapid antidepressant-like effects in adult corticosterone (CORT)-induced depressed rats, whether administered repeatedly or acutely. However, these effects remain unexplored in the context of post-partum depression (PPD).MethodsThis study investigated the antidepressant-like effect of a single injection of reelin in a CORT-induced model of PPD. Long-Evans female dams received either daily subcutaneous CORT (40 mg/kg) or saline injections (controls) from the post-partum day (PD) 2 to 22, and on PD22 were treated with a single intravenous reelin (3 μg) or vehicle injection.ResultsReelin treatment fully normalized to control levels the CORT-induced increase in Forced Swim Test (FST) immobility and the decrease in reelin-positive cells in the subgranular zone of the intermediate hippocampus. It also increased the number of oxytocin-positive cells in the paraventricular nucleus (PVN), the number of reelin-positive cells in the dorsal and ventral hippocampus, and the dendritic complexity of newborn neurons in the intermediate hippocampus, causing a partial recovery compared to controls. None of these changes were associated with fluctuations in estrogen levels measured peripherally.DiscussionThis study brings new insights into the putative antidepressant-like effect of peripherally administered reelin in an animal model of PPD. Future studies should be conducted to investigate these effects on a dose–response paradigm and to further elucidate the mechanisms underlying the antidepressant-like effects of reelin
A randomized controlled trial to assess the clinical and cost effectiveness of a nurse-led Antenatal Asthma Management Service in South Australia (AAMS study)
Background: Pregnancy presents a unique situation for the management of asthma as it can alter the course of asthma severity and its treatment, which in turn can affect pregnancy outcomes. Despite awareness of the substantial adverse effects associated with asthma during pregnancy, little has been done to improve its management and reduce associated perinatal morbidity and mortality. The aim of this randomized controlled trial is to evaluate the clinical and cost effectiveness of an Antenatal Asthma Management Service. Methods/design: Design: Multicentre, randomized controlled trial. Inclusion criteria: Women with physician diagnosed asthma, which is not currently in remission, who are less than 20 weeks gestation with a singleton pregnancy and do not have a chronic medical condition. Trial entry and randomization: Eligible women with asthma, stratified by treatment site, disease severity and parity, will be randomized into either the ‘Standard Care Group’ or the ‘Intervention Group’. Study groups: Both groups will be followed prospectively throughout pregnancy. Women in the ‘Standard Care Group’ will receive routine obstetric care reflecting current clinical practice in Australian hospitals. Women in the ‘Intervention Group’ will receive additional care through the nurse-led Antenatal Asthma Management Service, based in the antenatal outpatient clinic. Women will receive asthma education with a full assessment of their asthma at 18, 24, 30 and 36 weeks gestation. Each antenatal visit will include a 60 min session where asthma management skills are assessed including: medication adherence and knowledge, inhaler device technique, recognition of asthma deterioration and possession of a written asthma action plan. Furthermore, subjects will receive education about asthma control and management skills including trigger avoidance and smoking cessation counseling when appropriate. Primary study outcome: Asthma exacerbations during pregnancy. Sample size: A sample size of 378 women will be sufficient to show an absolute reduction in asthma exacerbations during pregnancy of 20% (alpha 0.05 two-tailed, 90% power, 5% loss to follow-up). Discussion: The integration of an asthma education program within the antenatal clinic setting has the significant potential to improve the participation of pregnant women in the self-management of their asthma, reduce asthma exacerbations and improve perinatal health outcomes.Luke E Grzeskowiak, Gustaaf Dekker, Karen Rivers, Kate Roberts-Thomson, Anil Roy, Brian Smith, Jeffery Bowden, Robert Bryce, Michael Davies, Justin Beilby, Anne Wilson, Philippa Middleton, Richard Ruffin, Jonathan Karnon, Vicki L Clifton and for the AAMS study grou
Disparity in Reimbursement for Tuberculosis Care Among Different Health Insurance Schemes: Evidence from Three Counties in Central China
Background:
Health inequity is an important issue all around the world. The Chinese basic medical security system comprises three major insurance schemes, namely the Urban Employee Basic Medical Insurance (UEBMI), the Urban Resident Basic Medical Insurance (URBMI), and the New Cooperative Medical Scheme (NCMS). Little research has been conducted to look into the disparity in payments among the health insurance schemes in China. In this study, we aimed to evaluate the disparity in reimbursements for tuberculosis (TB) care among the abovementioned health insurance schemes.
Methods:
This study uses a World Health Organization (WHO) framework to analyze the disparities and equity relating to the three dimensions of health insurance: population coverage, the range of services covered, and the extent to which costs are covered. Each of the health insurance scheme’s policies were categorized and analyzed. An analysis of the claims database of all hospitalizations reimbursed from 2010 to 2012 in three counties of Yichang city (YC), which included 1506 discharges, was conducted to identify the differences in reimbursement rates and out-of-pocket (OOP) expenses among the health insurance schemes.
Results:
Tuberculosis patients had various inpatient expenses depending on which scheme they were covered by (TB patients covered by the NCMS have less inpatient expenses than those who were covered by the URBMI, who have less inpatient expenses than those covered by the UEBMI). We found a significant horizontal inequity of healthcare utilization among the lower socioeconomic groups. In terms of financial inequity, TB patients who earned less paid more. The NCMS provides modest financial protection, based on income. Overall, TB patients from lower socioeconomic groups were the most vulnerable.
Conclusion:
There are large disparities in reimbursement for TB care among the three health insurance schemes and this, in turn, hampers TB control. Reducing the gap in health outcomes between the three health insurance schemes in China should be a focus of TB care and control. Achieving equity through integrated policies that avoid discrimination is likely to be effective
What explains rare and conspicuous colours in a snail? A test of time-series data against models of drift, migration or selection
It is intriguing that conspicuous colour morphs of a prey species may be maintained at low frequencies alongside cryptic morphs. Negative frequency-dependent selection by predators using search images ('apostatic selection') is often suggested without rejecting alternative explanations. Using a maximum likelihood approach we fitted predictions from models of genetic drift, migration, constant selection, heterozygote advantage or negative frequency-dependent selection to time-series data of colour frequencies in isolated populations of a marine snail (Littorina saxatilis), re-established with perturbed colour morph frequencies and followed for >20 generations. Snails of conspicuous colours (white, red, banded) are naturally rare in the study area (usually <10%) but frequencies were manipulated to levels of ~50% (one colour per population) in 8 populations at the start of the experiment in 1992. In 2013, frequencies had declined to ~15-45%. Drift alone could not explain these changes. Migration could not be rejected in any population, but required rates much higher than those recorded. Directional selection was rejected in three populations in favour of balancing selection. Heterozygote advantage and negative frequency-dependent selection could not be distinguished statistically, although overall the results favoured the latter. Populations varied idiosyncratically as mild or variable colour selection (3-11%) interacted with demographic stochasticity, and the overall conclusion was that multiple mechanisms may contribute to maintaining the polymorphisms.Heredity advance online publication, 21 September 2016; doi:10.1038/hdy.2016.77
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