145 research outputs found
A New Model of Roche-Lobe Overflow for Short-Period Gaseous Planets and Binary Stars
Some close-in gaseous exoplanets are nearly in Roche-lobe contact, and previous studies show tidal decay can drive hot Jupiters into contact during the main sequence of their host stars. Improving upon a previous model, we present a revised model for mass transfer in a semi-detached binary system that incorporates an extended atmosphere around the donor and allows for an arbitrary mass ratio. We apply this new formalism to hypothetical, confirmed, and candidate planetary systems to estimate mass loss rates and compare with models of evaporative mass loss. Overflow may be significant for hot Neptunes out to periods of ⌠2 days, while for hot Jupiters, it may only be important inward of 0.5 days. We find that CoRoT-24 b may be losing mass at a rate of more than an Earth mass in a Gyr. The hot Jupiter WASP-12 b may lose an Earth mass in a Myr, while the putative planet orbiting a T-Tauri star PTFO8-8695 might shed its atmosphere in a few Myrs. We point out that the orbital expansion that can accompany mass transfer may be less effective than previously considered because the gas accreted by the host star removes some of the systemâs angular momentum from the orbit, but simple scaling arguments suggest that the Roche-lobe overflow might remain stable. Consequently, the recently discovered small planets in ultra-short-periods (\u3c 1 day) may not be the remnants of hot Jupiters/Neptunes. The new model presented here has been incorporated into Modules for Experiments in Stellar Astrophysics (MESA)
Newborn resuscitation in Gombe State, northeastern Nigeria.
BACKGROUND: Basic newborn resuscitation for babies not breathing at birth is a highly effective intervention and its scale-up identified as a top research priority. However, tracking progress on the scale-up and coverage of this intervention is compromised by limitations in measuring both the number of newborns receiving the intervention and the number of newborns requiring the intervention. Using data from a facility and birth attendant survey in Gombe State, Nigeria, we aimed to advance the measurement agenda by developing a proxy indicator defined as the "percent of newborns born in a facility with the potential to provide newborn resuscitation". METHODS: The indicator's denominator was defined as: the total number of births in facilities during a defined time period (facility records). The numerator was constructed from the number of those births that occurred in appropriately equipped facilities (facility inventory), where a birth attendant demonstrated basic resuscitation competence (assessed by a simulation exercise). The proportion of facility-births that took place in a setting with the potential to provide newborn resuscitation was then calculated. RESULTS: The analysis included 17â383 births that occurred during May-October 2015 in 117 primary and referral facilities surveyed in November 2015. Overall 81% of the facilities did not have all items of essential equipment required for resuscitation; the items of equipment least frequently present included a timing device and resuscitation bag with two sizes of neonatal face mask. Only 3% of 117 birth attendants interviewed demonstrated competence to undertake resuscitation, all of whom were classified as skilled attendants and worked in referral facilities. We found that 20% of the 17â383 births took place in a facility with the potential to provide lifesaving resuscitation care. CONCLUSIONS: The indicator definition of neonatal resuscitation presented here responds to the need to advance the measurement agenda for newborn care and importantly adjusts for the volume of births occurring in different facilities. Its application in this setting revealed substantial missed opportunities to providing lifesaving care and highlights the need for a greater focus on input as well as process quality in all levels of health facilities
Hydatellaceae identified as a new branch near the base of the angiosperm phylogenetic tree
Although the relationship of angiosperms to other seed plants remains controversial, great progress has been made in identifying the earliest extant splits in flowering-plant phylogeny, with the discovery that the New Caledonian shrub Amborella trichopoda, the water lilies (Nymphaeales), and the woody Austrobaileyales constitute a basal grade of lines that diverged before the main radiation in the clade. By focusing attention on these ancient lines, this finding has re-written our understanding of angiosperm structural and reproductive biology, physiology, ecology and taxonomy. The discovery of a new basal lineage would lead to further re-evaluation of the initial angiosperm radiation, but would also be unexpected, as nearly all of the âŒ460 flowering-plant families have been surveyed in molecular studies. Here we show that Hydatellaceae, a small family of dwarf aquatics that were formerly interpreted as monocots, are instead a highly modified and previously unrecognized ancient lineage of angiosperms. Molecular phylogenetic analyses of multiple plastid genes and associated noncoding regions from the two genera of Hydatellaceae identify this overlooked family as the sister group of Nymphaeales. This surprising result is further corroborated by evidence from the nuclear gene phytochrome C (PHYC), and by numerous morphological characters. This indicates that water lilies are part of a larger lineage that evolved more extreme and diverse modifications for life in an aquatic habitat than previously recognized. ©2007 Nature Publishing Group
Mental healthcare in young people and young adults. Report 2
Report I and Report 2 both focus on patients with three common mental health conditions and one behaviour: eating disorders, depression, anxiety and self-harm... Report 2 focuses on an analysis of routinely collected national datasets for patients aged 11-24 years (up to their 25th birthday) and how they used healthcare services over a ten-year period between 2004 and 2014
Child Health Clinical Outcome Review Programme: The Mental Healthcare of Young People and Young Adults
The diagnosis, management and services available for mental disorders are of growing concern and controversy in the UK. Transitional care between child and adult services and the interface between primary and secondary/ specialist services is often disjointed and thresholds for referral to Child and Adolescent Mental Health Services are high.
Objectives and Approach
Routinely collected healthcare datasets and data linkage were used to identify patterns of healthcare utilisation by young people and young adults with mental health disorders across the four UK Nations. We explored the extent to which routinely collected datasets can contribute to an assessment of the health needs and the quality of care that children and young people with mental health disorders receive.
Data was requested from the national data providers in each country. A series of descriptive analyses were performed and methods were developed for cross- national comparisons to be made (e.g. Four Nation Person Spell).
Results
It is feasible to explore healthcare utilisation across the four countries of the UK using routine data. However the recording, availability and access varied considerably between countries, making meaningful comparisons challenging.
Descriptive analyses showed strong deprivation gradients in the diagnoses and care provided for young people and young adults with mental health disorders. Depression and anxiety were the most commonly recorded mental health conditions in primary care. In secondary care drug/alcohol disorders and self-harm were the most commonly recorded. Re-admissions to emergency departments were higher for those admitted for self-harm or psychiatric conditions.
Conclusion/Implications
Routine data has the potential to make a difference to care. However collection and access needs to be standardised in order to improve efficiency and effectiveness in improving the care for children and young people with mental health disorders. MQ has funded an Adolescent Data Platform to facilitate this
Unravelling the sources of lead in the urban soils of Greater Glasgow.
Lead (Pb) is toxic to all life and even low blood Pb levels can have neurological effects, especially in children <6. With two thirds of the world's population projected to inhabit urban areas by 2050, elevated Pb levels in urban soils is of especial concern due to the high number of children exposed. This project aims to design a model to predict soil Pb values in urban areas, in order to guide future remediation of Pb polluted soils. Such models require in depth understanding of the sources of Pb in urban soils. Subsequently, the factors influencing soil Pb levels were extracted from the literature and tested in Greater Glasgow using the British Geological Survey (BGS) Geochemical Baseline of the Environment (G-BASE) dataset
Improving inpatient postnatal services: midwives views and perspectives of engagement in a quality improvement initiative
Background: despite major policy initiatives in the United Kingdom to enhance women's experiences of maternity care, improving in-patient postnatal care remains a low priority, although it is an aspect of care consistently rated as poor by women. As part of a systems and process approach to improving care at one maternity unit in the South of England, the views and perspectives of midwives responsible for implementing change were sought.
Methods: a Continuous Quality Improvement (CQI) approach was adopted to support a systems and process change to in-patient care and care on transfer home in a large district general hospital with around 6000 births a year. The CQI approach included an initial assessment to identify where revisions to routine systems and processes were required, developing, implementing and evaluating revisions to the content and documentation of care in hospital and on transfer home, and training workshops for midwives and other maternity staff responsible for implementing changes. To assess midwifery views of the quality improvement process and their engagement with this, questionnaires were sent to those who had participated at the outset.
Results: questionnaires were received from 68 (46%) of the estimated 149 midwives eligible to complete the questionnaire. All midwives were aware of the revisions introduced, and two-thirds felt these were more appropriate to meet the women's physical and emotional health, information and support needs. Some midwives considered that the introduction of new maternal postnatal records increased their workload, mainly as a consequence of colleagues not completing documentation as required.
Conclusions: this was the first UK study to undertake a review of in-patient postnatal services. Involvement of midwives at the outset was essential to the success of the initiative. Midwives play a lead role in the planning and organisation of in-patient postnatal care and it was important to obtain their feedback on whether revisions were pragmatic and achieved anticipated improvements in care quality. Their initial involvement ensured priority areas for change were identified and implemented. Their subsequent feedback highlighted further important areas to address as part of CQI to ensure best quality care continues to be implemented. Our findings could support other maternity service organisations to optimise in-patient postnatal services
What is an admission? A standardised approach to classifying inpatient episode data from multiple jurisdictions
Introduction
Inpatient datasets in the UK are primarily organised by episodes (periods of care under an individual consultant), while researchers often want to measure admissions (periods of stay in hospital). We developed a standardized method for identifying admissions in inpatient data, while accounting for differences between the four UK nations.
Objectives and Approach
All UK inpatient datasets include date variables, permitting chronological sequencing of episodes. They include flags describing whether an episode is a transfer of care, although structures and definitions differ. Data quality is variable leading to concurrent and overlapping episodes, duplication and âorphanâ or âchildlessâ transfer episodes, where no originating or destination episode can be identified.
Our objective was to define a method for classifying individual episodes into a continuous period of stay in hospital, which would be consistently applicable to the analysis of inpatient datasets of all four UK nations, while prioritising clinical meaningfulness. Three permutations were considered.
Results
For each permutation, episodes for an individual were linked when they related to the same individual and met the following criteria:
âą Zero or one day gap between episode end and subsequent episode start
âą Evidence of transfer according to admission method or discharge destination variables
âą Episode overlapping or completely nested within another episode
Permutations:
âą a and b
âą a only
âą a and c
Permutation three was adopted, as it was felt to be the most clinically meaningful approach, was not dependent on accurate recording of transfers and captured nested or overlapping episodes, which may occur for example when a patient is in a long-stay psychiatric or elderly care ward but requires care from a different specialty. Importantly it permitted consistent analysis of episodes across all UK nations.
Conclusion/Implications
The output of this work provides a useful guide for the classification of inpatient episodes into more clinically meaningful periods of care, and is applicable to the inpatient datasets of all four UK nations. It describes important issues to consider when classifying episodes of care, particularly relating to data quality
Gemini multi-conjugate adaptive optics system review II: Commissioning, operation and overall performance
The Gemini Multi-conjugate Adaptive Optics System - GeMS, a facility
instrument mounted on the Gemini South telescope, delivers a uniform, near
diffraction limited images at near infrared wavelengths (0.95 microns- 2.5
microns) over a field of view of 120 arc seconds. GeMS is the first sodium
layer based multi laser guide star adaptive optics system used in astronomy. It
uses five laser guide stars distributed on a 60 arc seconds square
constellation to measure for atmospheric distortions and two deformable mirrors
to compensate for it. In this paper, the second devoted to describe the GeMS
project, we present the commissioning, overall performance and operational
scheme of GeMS. Performance of each sub-system is derived from the
commissioning results. The typical image quality, expressed in full with half
maximum, Strehl ratios and variations over the field delivered by the system
are then described. A discussion of the main contributor to performance
limitation is carried-out. Finally, overheads and future system upgrades are
described.Comment: 20 pages, 11 figures, accepted for publication in MNRA
A qualitative study of the experiences and expectations of women receiving in-patient postnatal care in one English maternity unit
Background Studies consistently highlight in-patient postnatal care as the area of maternity care women are least satisfied with. As part of a quality improvement study to promote a continuum of care from the birthing room to discharge home from hospital, we explored womenâs expectations and experiences of current inpatient care. Methods For this part of the study, qualitative data from semi-structured interviews were transcribed and analysed using content analyses to identify issues and concepts. Women were recruited from two postnatal wards in one large maternity unit in the South of England, with around 6,000 births a year. Results Twenty women, who had a vaginal or caesarean birth, were interviewed on the postnatal ward. Identified themes included; the impact of the ward environment; the impact of the attitude of staff; quality and level of support for breastfeeding; unmet information needs; and womenâs low expectations of hospital based postnatal care. Findings informed revision to the content and planning of in-patient postnatal care, results of which will be reported elsewhere. Conclusions Womenâs responses highlighted several areas where changes could be implemented. Staff should be aware that how they inter-act with women could make a difference to care as a positive or negative experience. The lack of support and inconsistent advice on breastfeeding highlights that units need to consider how individual staff communicate information to women. Units need to address how and when information on practical aspects of infant care is provided if women and their partners are to feel confident on the womanâs transfer home from hospital
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