302 research outputs found
QED calculation of the n=1 and n=2 energy levels in He-like ions
We perform ab initio QED calculations of energy levels for the and
states of He-like ions with the nuclear charge in the range -100.
The complete set of two-electron QED corrections is evaluated to all orders in
the parameter \aZ. Uncalculated contributions to energy levels come through
orders \alpha^3 (\aZ)^2, \alpha^2 (\aZ)^7, and higher. The calculation
presented is the first treatment for excited states of He-like ions complete
through order \alpha^2 (\aZ)^4. A significant improvement in accuracy of
theoretical predictions is achieved, especially in the high- region.Comment: 23 pages, 5 figure
Assessing the accuracy of quantitative molecular microbial profiling
This is the final version of the article. Available from MDPI via the DOI in this record.The application of high-throughput sequencing in profiling microbial communities is providing an unprecedented ability to investigate microbiomes. Such studies typically apply one of two methods: amplicon sequencing using PCR to target a conserved orthologous sequence (typically the 16S ribosomal RNA gene) or whole (meta)genome sequencing (WGS). Both methods have been used to catalog the microbial taxa present in a sample and quantify their respective abundances. However, a comparison of the inherent precision or bias of the different sequencing approaches has not been performed. We previously developed a metagenomic control material (MCM) to investigate error when performing different sequencing strategies. Amplicon sequencing using four different primer strategies and two 16S rRNA regions was examined (Roche 454 Junior) and compared to WGS (Illumina HiSeq). All sequencing methods generally performed comparably and in good agreement with organism specific digital PCR (dPCR); WGS notably demonstrated very high precision. Where discrepancies between relative abundances occurred they tended to differ by less than twofold. Our findings suggest that when alternative sequencing approaches are used for microbial molecular profiling they can perform with good reproducibility, but care should be taken when comparing small differences between distinct methods. This work provides a foundation for future work comparing relative differences between samples and the impact of extraction methods. We also highlight the value of control materials when conducting microbial profiling studies to benchmark methods and set appropriate thresholds.The authors acknowledge funding from the European Metrology Research Programme joint research project “INFECT MET” (http://infectmet.lgcgroup.com) (an EMRP project, jointly funded by the EMRP participating countries within EURAMET and the European Union) and the UK National Measurement System for funding of this work and for the support of Thomas Laver by the BBSRC Industrial Case Studentship award BB/H016120/1
Cost effectiveness of alternative planned places of birth in woman at low risk of complications: evidence from the Birthplace in England national prospective cohort study
Objectives To estimate the cost effectiveness of alternative planned places of birth
Recommended from our members
Mapping maternity care: the configuration of maternity care in England. Birthplace in England research programme
Cognitive, emotional and environmental mediators of early parenting in high risk families
The UK currently has the highest number of premature births (babies born before 37 weeks gestation age and below 2.5kg) in Europe affecting around 70,000 babies and their caregivers each year. Consequently many interventions have been created to support the development of the preterm newborn and minimise the complications of prematurity. Many of the interventions developed have been predominantly tactile and have almost exclusively focused upon their effect upon the baby and not, for example considered the effect that this type of intervention might have upon the parents; specifically the mother, when they are the ones who perform the therapy. In fact there is a severe lack of systematic studies investigating the latter. Hence, the aim of this thesis was to search for research-based evidence on the benefits of environmental support to both babies (e.g. increased weight gain or awake periods) and their mothers (e.g. higher perceptions of themselves as a mother) during hospital confinement and within the context of Neonatal Health Psychology (NNHP). For this reason, the main hypothesis investigated whether mothers’ cognitions and emotions; specifically Maternal Self-Efficacy, Self-Esteem and Attachment, would be affected by environmental mediators in the form of structured or non-structured tactile sensory nurturing interventions. The empirical work reported in this thesis is divided into 3 distinct phases. Firstly, as their was no appropriate measure of maternal Self-Efficacy for mothers of hospitalised preterm neonates the main aim of Phase-1 was to develop and validate an appropriate measure. Using a prospective survey method and a mixed design (between/within and correlational) a total of 160 mother-preterm dyads (pooled from 2 cohorts; cohort 1, N=100; cohort 2, N=60) were recruited. The results demonstrated that the Perceived Maternal Parenting Self-Efficacy (PMPS-E) tool had good initial psychometric properties (including internal/external reliability and construct validity) for its use with mothers of relatively healthy hospitalised preterm neonates. Secondly, in order to investigate mothers’ perceived maternal parenting self-efficacy beliefs further Phase-2 examined whether the type of feeding a mother chose to give to her baby mediated her self-efficacy beliefs. The results suggested that breastfeeding a preterm neonate during hospital confinement may adversely affect mothers’ perceptions of their efficacy in all aspects of parenting. Finally, using an experimental method Phase-3 tested the main hypothesis of this thesis and used a randomised cluster control trial (RCCT) design to allocate 60 mothers and their preterms equally to one of three cluster groups; consisting of either structured (e.g. TAC-TIC therapy or Using a Toy) or non-structured (Placebo/Control) tactile sensory nurturing interventions. The main findings illustrate that tactile sensory nurturing interventions do mediate maternal cognitions and emotions, preterm weight gain and behavioural state. In particular, mothers who performed TAC-TIC demonstrated significantly higher self-reported perceptions in their self-efficacy, self-esteem and attachment, which was attributed to the fact that these babies spent increased amounts of time in an alert and responsive behavioural state, and gained more weight throughout the study period. Thus, the work presented throughout this thesis has implications for Neonatal Health Psychologists and other Health Care professionals’ practice within neonatal units, the use of Neonatal Health Psychology as a framework to study the preterm neonate and their family, and also the way in which both mothers and their hospitalised preterm neonates are supported during hospital confinement.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Recommended from our members
The Birthplace in England national prospective cohort study: further analyses to enhance policy and service delivery decision-making for planned place of birth
Background: Evidence from the Birthplace in England Research Programme supported a policy of offering ‘low risk’ women a choice of birth setting, but a number of unanswered questions remained.
Aims: This project aimed to provide further evidence to support the development and delivery of maternity services and inform women’s choice of birth setting: specifically, to explore maternal and organisational factors associated with intervention, transfer and other outcomes in each birth setting in ‘low risk’ and ‘higher risk’ women.
Design: Five component studies using secondary analysis of the Birthplace prospective cohort study (studies 2–5) and ecological analysis of unit/NHS trust-level data (studies 1 and 5).
Setting: Obstetric units (OUs), alongside midwifery units (AMUs), freestanding midwifery units (FMUs) and planned home births in England.
Participants: Studies 1–4 focused on ‘low risk’ women with ‘term’ pregnancies planning vaginal birth in 43 AMUs (n = 16,573), in 53 FMUs (n = 11,210), at home in 147 NHS trusts (n = 16,632) and in a stratified, random sample of 36 OUs (n = 19,379) in 2008–10. Study 5 focused on women with pre-existing medical and obstetric risk factors (‘higher risk’ women).
Main outcome measures: Interventions (instrumental delivery, intrapartum caesarean section), a measure of low intervention (‘normal birth’), a measure of spontaneous vaginal birth without complications (‘straightforward birth’), transfer during labour and a composite measure of adverse perinatal outcome (‘intrapartum-related mortality and morbidity’ or neonatal admission within 48 hours for > 48 hours). In studies 1 and 3, rates of intervention/maternal outcome and transfer were adjusted for maternal characteristics.
Analysis: We used (a) funnel plots to explore variation in rates of intervention/maternal outcome and transfer between units/trusts, (b) simple, weighted linear regression to evaluate associations between unit/trust characteristics and rates of intervention/maternal outcome and transfer, (c) multivariable Poisson regression to evaluate associations between planned place of birth, maternal characteristics and study outcomes, and (d) logistic regression to investigate associations between time of day/day of the week and study outcomes.
Results: Study 1 – unit-/trust-level variations in rates of interventions, transfer and maternal outcomes were not explained by differences in maternal characteristics. The magnitude of identified associations between unit/trust characteristics and intervention, transfer and outcome rates was generally small, but some aspects of configuration were associated with rates of transfer and intervention. Study 2 – ‘low risk’ women planning non-OU birth had a reduced risk of intervention irrespective of ethnicity or area deprivation score. In nulliparous women planning non-OU birth the risk of intervention increased with increasing age, but women of all ages planning non-OU birth experienced a reduced risk of intervention. Study 3 – parity, maternal age, gestational age and ‘complicating conditions’ identified at the start of care in labour were independently associated with variation in the risk of transfer in ‘low risk’ women planning non-OU birth. Transfers did not vary by time of day/day of the week in any meaningful way. The duration of transfer from planned FMU and home births was around 50–60 minutes; transfers for ‘potentially urgent’ reasons were quicker than transfers for ‘non-urgent’ reasons. Study 4 – the occurrence of some interventions varied by time of the day/day of the week in ‘low risk’ women planning OU birth. Study 5 – ‘higher risk’ women planning birth in a non-OU setting had fewer risk factors than ‘higher risk’ women planning OU birth and these risk factors were different. Compared with ‘low risk’ women planning home birth, ‘higher risk’ women planning home birth had a significantly increased risk of our composite adverse perinatal outcome measure. However, in ‘higher risk’ women, the risk of this outcome was lower in planned home births than in planned OU births, even after adjustment for clinical risk factors.
Conclusions: Expansion in the capacity of non-OU intrapartum care could reduce intervention rates in ‘low risk’ women, and the benefits of midwifery-led intrapartum care apply to all ‘low risk’ women irrespective of age, ethnicity or area deprivation score. Intervention rates differ considerably between units, however, for reasons that are not understood. The impact of major changes in the configuration of maternity care on outcomes should be monitored and evaluated. The impact of non-clinical factors, including labour ward practices, staffing and skill mix and women’s preferences and expectations, on intervention requires further investigation. All women planning non-OU birth should be informed of their chances of transfer and, in particular, older nulliparous women and those more than 1 week past their due date should be advised of their increased chances of transfer. No change in the guidance on planning place of birth for ‘higher risk’ women is recommended, but research is required to evaluate the safety of planned AMU birth for women with selected relatively common risk factors.
Funding: The National Institute for Health Research Health Services and Delivery Research programme
A randomised trial of granulocyte-macrophage colony-stimulating factor for neonatal sepsis: outcomes at 2 years
The authors performed a randomised trial in very preterm small-for-gestational age (SGA) babies to determine if prophylaxis with granulocyte-macrophage colony-stimulating factor (GM-CSF) improves outcomes (the PROGRAMS trial). Despite increased neutrophil counts following GM-CSF, the authors reported no significant difference in neonatal sepsis-free survival
Perinatal and maternal outcomes in planned home and obstetric unit births in women at ‘higher risk’ of complications: secondary analysis of the Birthplace national prospective cohort study
Objective: To explore and compare perinatal and maternal outcomes in women at ‘higher risk’ of complications planning home versus obstetric unit (OU) birth.
Design: Prospective cohort study.
Setting: OUs and planned home births in England.
Population: 8180 ‘higher risk’ women in the Birthplace cohort.
Methods: We used Poisson regression to calculate relative risks adjusted for maternal characteristics. Sensitivity analyses explored possible effects of differences in risk between groups and alternative outcome measures.
Main outcome measures: Composite perinatal outcome measure encompassing ‘intrapartum related mortality and morbidity’ (intrapartum stillbirth, early neonatal death, neonatal encephalopathy, meconium aspiration syndrome, brachial plexus injury, fractured humerus or clavicle) and neonatal admission within 48 hours for more than 48 hours. Two composite maternal outcome measures capturing intrapartum interventions/adverse maternal outcomes and straightforward birth.
Results: The risk of ‘intrapartum related mortality and morbidity’ or neonatal admission for more than 48 hours was lower in planned home births than planned OU births [adjusted relative risks (RR) 0.50, 95% CI 0.31–0.81]. Adjustment for clinical risk factors did not materially affect this finding. The direction of effect was reversed for the more restricted outcome measure ‘intrapartum related mortality and morbidity’ (RR adjusted for parity 1.92, 95% CI 0.97–3.80). Maternal interventions were lower in planned home births.
Conclusions: The babies of ‘higher risk’ women who plan birth in an OU appear more likely to be admitted to neonatal care than those whose mothers plan birth at home, but it is unclear if this reflects a real difference in morbidity. Rates of intrapartum related morbidity and mortality did not differ statistically significantly between settings at the 5% level but a larger study would be required to rule out a clinically important difference between the groups
Needs assessment to strengthen capacity in water and sanitation research in Africa:experiences of the African SNOWS consortium
Despite its contribution to global disease burden, diarrhoeal disease is still a relatively neglected area for research funding, especially in low-income country settings. The SNOWS consortium (Scientists Networked for Outcomes from Water and Sanitation) is funded by the Wellcome Trust under an initiative to build the necessary research skills in Africa. This paper focuses on the research training needs of the consortium as identified during the first three years of the project
- …