552 research outputs found
Maternal Age, Paternal Age and Effective Fecundability in Rural Bangladesh
Effective fecundability is defined as the monthly probability for a conception that leads to a livebirth. One method of assessing effective fecundability is by examining lengths of first birth intervals. Using demographic records of marriage and birth, we examine the effects of maternal age, paternal age, mother’s education, and religion on effective fecundability in a rural region of Bangladesh. Data came from a prospective demographic and health survey conducted in Matlab thana by the International Centre for Diarrhoeal Disease Research, Bangladesh. Marriage and birth records from 1975 to 1982 were used to generate first birth intervals. A parametric hazards model of fecundability was used to simultaneously estimate primary sterility, effective fecundability as well as effects of fixed and time varying covariates on effective fecundability. Marriage records were matched for 10,255 pairs of partners, including exact times to birth and observations right censored by death, divorce, migration, or the end of record-keeping. The age range at marriage for wives was 12 and 25 years. The prevalence of primary sterility was 5.1% (± 2.6% SE). The estimate of effective fecundability was 0.053 (±0.002). The most parsimonious model showed reduced fecundability for women under 16 years and highest fecundability from 17 to 19 years, relative to the reference age group (20 to 25) years. Fecundability was significantly higher for father’s age 25 to 29 years relative to other ages. Religion and mother’s education were not associated with fecundability. The results suggest that Bangladeshi women have a higher prevalence of sterility and lower effective fecundability compared to other samples in developing settings
Investigating the Evidence of the Real-Life Impact of Acute Hyperglycaemia
Poorly controlled diabetes mellitus (DM) is associated with the development of long-term micro- and macro-vascular complications. The predominant focus of anti-diabetic therapy has been on lowering glycosylated haemoglobin levels, with a strong emphasis on fasting plasma glucose (particularly in Type 2 DM). There is considerable evidence indicating that post-meal hyperglycaemic levels are independently associated with higher risks of macro-vascular disease. Although some have identified mechanisms which may account for these observations, interventions which have specifically targeted postprandial glucose rises showed little or no effect in reducing cardiovascular risk. Clinical experience and some recent studies suggest acute hyperglycaemia affects cognition and other indicators of performance, equivalent to impairment seen during hypoglycaemia. In this brief report, we evaluated the published studies and argue that acute hyperglycaemia is worth investigating in relation to the real-life implications. In summary, evidence exists suggesting that acute hyperglycaemia may lead to impaired cognitive performance and productivity, but the relationship between these effects and daily activities remains poorly understood. Further research is required to enhance our understanding of acute hyperglycaemia in daily life. A better appreciation of clinically relevant effects of acute hyperglycaemia will allow us to determine whether it needs to be addressed by specific treatment
Gravitational Microlensing Evidence for a Planet Orbiting a Binary Star System
The study of extra-solar planetary systems has emerged as a new discipline of
observational astronomy in the past few years with the discovery of a number of
extra-solar planets. The properties of most of these extra-solar planets were
not anticipated by theoretical work on the formation of planetary systems. Here
we report observations and light curve modeling of gravitational microlensing
event MACHO-97-BLG-41, which indicates that the lens system consists of a
planet orbiting a binary star system. According to this model, the mass ratio
of the binary star system is 3.8:1 and the stars are most likely to be a late K
dwarf and an M dwarf with a separation of about 1.8 AU. A planet of about 3
Jupiter masses orbits this system at a distance of about 7 AU. If our
interpretation of this light curve is correct, it represents the first
discovery of a planet orbiting a binary star system and the first detection of
a Jovian planet via the gravitational microlensing technique. It suggests that
giant planets may be common in short period binary star systems.Comment: 11 pages, with 1 color and 2 b/w Figures included (published version
The anomalous U(1) global symmetry and flavors from an SU(5) x SU(5) GUT in orbifold compactification
In string compactifications, frequently there appears the anomalous U(1)
gauge symmetry which belonged to E8E8 of the heterotic string. This
anomalous U(1) gauge boson obtains mass at the compactification scale, just
below GeV, by absorbing one pseudoscalar (corresponding to the
model-independent axion) from the second rank anti-symmetric tensor field
.
Below the compactification scale, there results a global symmetry U(1) whose charge is the original gauge U(1) charge. This is
the most natural global symmetry, realizing the "invisible" axion. This global
symmetry U(1) is suitable for a flavor symmetry. In the simplest
compactification model with the flipped SU(5) grand unification, we calculate
all the low energy parameters in terms of the vacuum expectation values of the
standard model singlets.Comment: 18 pages, 4 figur
Impact of population ageing on the cost of hospitalisations for cardiovascular disease: a population-based data linkage study
Background: Cardiovascular disease (CVD) is the most costly disease in Australia. Measuring the impact of ageing on its costs is needed for planning future healthcare budget. The aim of this study was to measure the impact of changes in population age structure in Western Australia (WA) on the costs of hospitalisation for CVD. Methods: All hospitalisation records for CVD occurring in WA in 1993/94 and 2003/04 inclusive were extracted from the WA Hospital Morbidity Data System (HMDS) via the WA Data Linkage System. Inflation adjusted hospitalisation costs using 2012 as the base year was assigned to all episodes of care using Australian Refined Diagnosis Related Group (AR-DRG) costing information. The component decomposition method was used to measure the contribution of ageing and other factors to the increase of hospitalisation costs for CVD. Results: Between 1993/94 and 2003/04, population ageing contributed 23% and 30% respectively of the increase in CVD hospitalisation costs for men and women. The impact of ageing on hospitalisation costs was far greater for chronic conditions than acute coronary syndrome (ACS) and stroke. Conclusions: Given the impact of ageing on hospitalisation costs, and the disparity between chronic and acute conditions, disease-specific factors should be considered in planning for future healthcare expenditure
From whole bodies to single cells : a guide to transcriptomic approaches for ecology and evolutionary biology
Funding: The authors were assisted by a Special Topics Network (STN) grant from the European Society for Evolutionary Biology (ESEB) to facilitate networking of the European Drosophila Population Genomics consortium (DrosEU; https://droseu.net/). SG and NP are supported by a Deutsche Forschungsgemeinschaft grant (GR 4495/4-1, PO 1648/7-1, PO 1648/4-1). MGR is supported by Natural Environment Research Council, UK (NE/V001566/1). CS is supported by the Austrian Science Funds (P32935, P33734, W1225). TF is supported by the Swiss National Science Foundation (310030_219283, FZEB-0-214654, 31003A-182262). JG is supported by grant PID2020-115874GB-I00 funded by MCIN/AEI/10.13039/501100011033 and from grant 2021 SGR 00417 funded by Departament de Recerca i Universitats, Generalitat de Catalunya. MK was supported by the grant 322980 from The Research Council of Finland.RNA sequencing (RNAseq) methodology has experienced a burst of technological developments in the last decade, which has opened up opportunities for studying the mechanisms of adaptation to environmental factors at both the organismal and cellular level. Selecting the most suitable experimental approach for specific research questions and model systems can, however, be a challenge and researchers in ecology and evolution are commonly faced with the choice of whether to study gene expression variation in whole bodies, specific tissues, and/or single cells. A wide range of sometimes polarised opinions exists over which approach is best. Here, we highlight the advantages and disadvantages of each of these approaches to provide a guide to help researchers make informed decisions and maximise the power of their study. Using illustrative examples of various ecological and evolutionary research questions, we guide the readers through the different RNAseq approaches and help them identify the most suitable design for their own projects.Peer reviewe
An exploration of parents’ preferences for foot care in juvenile idiopathic arthritis: a possible role for the discrete choice experiment
Background:
An increased awareness of patients’ and parents’ care preferences regarding foot care is desirable from a clinical perspective as such information may be utilised to optimise care delivery. The aim of this study was to examine parents’ preferences for, and valuations of foot care and foot-related outcomes in juvenile idiopathic arthritis (JIA).<p></p>
Methods:
A discrete choice experiment (DCE) incorporating willingness-to-pay (WTP) questions was conducted by surveying 42 parents of children with JIA who were enrolled in a randomised-controlled trial of multidisciplinary foot care at a single UK paediatric rheumatology outpatients department. Attributes explored were: levels of pain; mobility; ability to perform activities of daily living (ADL); waiting time; referral route; and footwear. The DCE was administered at trial baseline. DCE data were analysed using a multinomial-logit-regression model to estimate preferences and relative importance of attributes of foot care. A stated-preference WTP question was presented to estimate parents’ monetary valuation of health and service improvements.<p></p>
Results:
Every attribute in the DCE was statistically significant (p < 0.01) except that of cost (p = 0.118), suggesting that all attributes, except cost, have an impact on parents’ preferences for foot care for their child. The magnitudes of the coefficients indicate that the strength of preference for each attribute was (in descending order): improved ability to perform ADL, reductions in foot pain, improved mobility, improved ability to wear desired footwear, multidisciplinary foot care route, and reduced waiting time. Parents’ estimated mean annual WTP for a multidisciplinary foot care service was £1,119.05.<p></p>
Conclusions:
In terms of foot care service provision for children with JIA, parents appear to prefer improvements in health outcomes over non-health outcomes and service process attributes. Cost was relatively less important than other attributes suggesting that it does not appear to impact on parents’ preferences.<p></p>
A randomised controlled trial to compare opt-in and opt-out parental consent for childhood vaccine safety surveillance using data linkage: study protocol
Extent: 10p.Background: The Vaccine Assessment using Linked Data (VALiD) trial compared opt-in and opt-out parental consent for a population-based childhood vaccine safety surveillance program using data linkage. A subsequent telephone interview of all households enrolled in the trial elicited parental intent regarding the return or non-return of reply forms for opt-in and opt-out consent. This paper describes the rationale for the trial and provides an overview of the design and methods. Methods/Design: Single-centre, single-blind, randomised controlled trial (RCT) stratified by firstborn status. Mothers who gave birth at one tertiary South Australian hospital were randomised at six weeks post-partum to receive an opt-in or opt-out reply form, along with information explaining data linkage. The primary outcome at 10 weeks post-partum was parental participation in each arm, as indicated by the respective return or non-return of a reply form (or via telephone or email response). A subsequent telephone interview at 10 weeks post-partum elicited parental intent regarding the return or non-return of the reply form, and attitudes and knowledge about data linkage, vaccine safety, consent preferences and vaccination practices. Enrolment began in July 2009 and 1,129 households were recruited in a three-month period. Analysis has not yet been undertaken. The participation rate and selection bias for each method of consent will be compared when the data are analysed. Discussion: The VALiD RCT represents the first trial of opt-in versus opt-out consent for a data linkage study that assesses consent preferences and intent compared with actual opting in or opting out behaviour, and socioeconomic factors. The limitations to generalisability are discussed.Jesia G Berry, Philip Ryan, Annette J Braunack-Mayer, Katherine M Duszynski, Vicki Xafis, Michael S Gold, the Vaccine Assessment Using Linked Data (VALiD) Working Grou
Oral contraceptive use and risk of melanoma in premenopausal women
Melanoma has been increasing in white populations. Incidence rates rise steeply in women until about age 50, suggesting oestrogen as a possible risk factor. Oestrogens can increase melanocyte count and melanin content and cause hyperpigmentation of the skin. We examined prospectively the association between oral contraceptive (OC) use and diagnoses of superficial spreading and nodular melanoma among 183 693 premenopausal white women in the Nurses’ Health Study (NHS) and the Nurses’ Health Study II (NHS II) cohorts. One hundred and forty six cases were confirmed in NHS during follow-up from 1976 to 1994, and 106 cases were confirmed in NHS II from 1989 to 1995. Skin reaction to sun exposure, sunburn history, mole counts, hair colour, family history of melanoma, parity, height and body mass index were also assessed and included in logistic regression models. A significant twofold increase in risk of melanoma (relative risk (RR) = 2.0, 95% confidence interval (CI) 1.2–3.4) was observed among current OC users compared to never users. Risk was further increased among current users with 10 or more years of use (RR = 3.4, 95% CI 1.7–7.0). Risk did not appear elevated among past OC users, even among those with longer durations of use, and risk did not decline linearly with time since last use. In conclusion, risk of premenopausal melanoma may be increased among women who are current OC users, particularly among those with longer durations of use. Further research is needed to determine whether low-dose oestrogen pills in particular are associated with an increase in risk and to describe possible interactions between OC use and sun exposure or other risk factors for melanoma. © 1999 Cancer Research Campaig
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