626 research outputs found
Atomic and Molecular Absorption in Redshifted Radio Sources
We report on a survey for associated HI 21-cm and OH 18-cm absorption with
the Giant Metrewave Radio Telescope at redshifts z = 0.2-0.4. Although the low
redshift selection ensures that our targets are below the critical ultra-violet
luminosity, which is hypothesised to ionise all of the neutral gas in the host
galaxy, we do not obtain any detections in the six sources searched. Analysing
these in context of the previous surveys, in addition to the anti-correlation
with the ultra-violet luminosity (ionising photon rate), we find a correlation
between the strength of the absorption and the blue -- near-infrared colour, as
well as the radio-band turnover frequency. We believe that these are due to the
photo-ionisation of the neutral gas, an obscured sight-line being more
conducive to the presence of cold gas and the compact radio emission being
better intercepted by the absorbing gas, maximising the flux coverage,
respectively. Regarding the photo-ionisation, the compilation of the previous
surveys increases the significance of the critical ionising photon rate, above
which all of the gas in the host galaxy is hypothesised to be ionised, to >5
sigma. This reaffirms that this is an ubiquitous effect, which has profound
implications for the detection of neutral gas in these objects with the Square
Kilometre Array.Comment: Accepted by MNRA
A fourth HI 21-cm absorption system in the sight-line of MG J0414+0534: a record for intervening absorbers
We report the detection of a strong HI 21-cm absorption system at z=0.5344,
as well as a candidate system at z=0.3389, in the sight-line towards the z=2.64
quasar MG J0414+0534. This, in addition to the absorption at the host redshift
and the other two intervening absorbers, takes the total to four (possibly
five). The previous maximum number of 21-cm absorbers detected along a single
sight-line is two and so we suspect that this number of gas-rich absorbers is
in some way related to the very red colour of the background source. Despite
this, no molecular gas (through OH absorption) has yet been detected at any of
the 21-cm redshifts, although, from the population of 21-cm absorbers as a
whole, there is evidence for a weak correlation between the atomic line
strength and the optical--near-infrared colour. In either case, the fact that
so many gas-rich galaxies (likely to be damped Lyman-alpha absorption systems)
have been found along a single sight-line towards a highly obscured source may
have far reaching implications for the population of faint galaxies not
detected in optical surveys, a possibility which could be addressed through
future wide-field absorption line surveys with the Square Kilometre Array.Comment: Accepted by ApJ Letter
Prevalence of gastroschisis at birth: Retrospective study
[No abstract available
A search for 21 cm HI absorption in AT20G compact radio galaxies
We present results from a search for 21 cm associated HI absorption in a
sample of 29 radio sources selected from the Australia Telescope 20 GHz survey.
Observations were conducted using the Australia Telescope Compact Array
Broadband Backend, with which we can simultaneously look for 21 cm absorption
in a redshift range of 0.04 < z < 0.08, with a velocity resolution of 7 km/s .
In preparation for future large-scale H I absorption surveys we test a
spectral-line finding method based on Bayesian inference. We use this to assign
significance to our detections and to determine the best-fitting number of
spectral-line components. We find that the automated spectral-line search is
limited by residuals in the continuum, both from the band-pass calibration and
spectral-ripple subtraction, at spectral-line widths of \Deltav_FWHM > 103 km/s
. Using this technique we detect two new absorbers and a third, previously
known, yielding a 10 per cent detection rate. Of the detections, the
spectral-line profiles are consistent with the theory that we are seeing
different orientations of the absorbing gas, in both the host galaxy and
circumnuclear disc, with respect to our line-of-sight to the source. In order
to spatially resolve the spectral-line components in the two new detections,
and so verify this conclusion, we require further high-resolution 21 cm
observations (~0.01 arcsec) using very long baseline interferometry.Comment: 16 pages, 8 figures and 5 tables; accepted for publication in MNRAS
(version 2 based on proof corrections
Knowledge, attitudes, and practices associated with vitamin D supplementation: A cross-sectional online community survey of adults in the UK
OBJECTIVE: Assess knowledge, attitudes, and practices (KAPs) of a diverse population. Identify barriers and facilitators that inform routine vitamin D supplementation and self-care in the community setting. DESIGN: Cross-sectional online voluntary survey. Electronic survey link published on college Qualtrics platform and advertised widely. Study information provided with Participant Information Sheet. SETTING AND PARTICIPANTS: 556 community dwelling adults across the UK. METHODS: The overarching study included two phases, incorporating quantitative and qualitative methodologies. This paper reports findings from the first phase of the FABCOM-D (Facilitators and Barriers to Community (Healthy) Vitamin D status) study. Online survey questions were iteratively developed after background literature searches and piloted to ensure clarity and ease of understanding. Survey responses summarised using frequencies and percentages, and univariable and multivariable logistic regression models explored for any association. A p-value less than 0.05 was considered statistically significant. The Checklist for Reporting Results of Internet E-Surveys guided reporting. Statistical analysis performed using IBM SPSS software. MAIN OUTCOME MEASURES: Awareness of vitamin D information sources, health benefits and testing. Attitudes to supplementation, sun exposure and fortification. RESULTS: Three quarters of the community had some awareness of vitamin D and around half were taking supplements. The two most trusted sources of information included health professionals and the NHS website. Participants were willing to pay for supplements, supporting a self-care agenda. With increasing age, there was significant reduced intake of vitamin D supplements. This aspect needs to be explored further as this could be a concern in deficiency status in the elderly. There was acceptance of food fortification but uncertainty on how to balance food intake with supplementation. CONCLUSION: We were successful in eliciting views on KAPs around vitamin D from a community population including a large proportion of Black and Minority Ethnic individuals. The community wanted information and guidance to help manage individual vitamin D status, especially for high-risk groups, and on balancing supplementation, food fortification and sun exposure
A qualitative evaluation to explore the suitability, feasibility and acceptability of using a 'celebration card' intervention in primary care to improve the uptake of childhood vaccinations.
BACKGROUND: Childhood vaccination remains a primary mechanism for reducing the burden of infectious disease. In the United Kingdom, as in many countries, a sustained effort is required to ensure that vaccination targets are met to afford protection to the whole population from vaccine preventable disease. The Celebrate and Protect programme is a collaborative partnership developed to improve the uptake of childhood vaccination across a number of boroughs within London through the use of a celebration card to encourage attendance for vaccination and enhance relationships between general practices and the parents/carers of children. METHODS: This study was undertaken to assess the suitability, feasibility and acceptability of the Celebrate and Protect programme across nine boroughs in London. Data were collected either from telephone interviews (n = 24) or from focus groups (n = 31). A total of 55 key informants were included in the study, representing strategic, commissioning or policy leads, healthcare professionals and primary care teams delivering vaccinations and parents/carers of children under five. RESULTS: The analysis of data identified that whilst parents/carers saw the celebration card positively this raised the issue of 'vaccine hesitancy' and the lack of information that parents/carers have to make informed decisions about vaccination. Similarly, healthcare professionals viewed the programme positively and felt that it was deliverable within existing resources although they raised wider questions about on-going sustainability and about quantitative data collection. In relation to the collaboration between primary care and a pharmaceutical company in developing the Celebrate and Protect programme, it was generally felt that, provided appropriate governance is in place, it was a pragmatic approach in which the benefits outweighed any perceived disadvantages. DISCUSSION: The Celebrate and Protect programme was seen as an innovative collaborative programme to engage with parents and carers of children in order to improve relationships between service users and providers and subsequently increase vaccination uptake. The analysis demonstrates that that the celebration card is suitable for its purpose, acceptable to both healthcare professionals and to parents/carers of children and the Celebrate and Protect programme has been able to deliver its aims. CONCLUSION: Whilst the delivery of the 'celebration card' intervention in primary met its objectives there are some outstanding issues in terms of the sustainability of the initiative and the ability to demonstrate quantitative improvements in vaccination uptake rates
Rapid prototype feasibility testing with simulation: Improvements and updates to the Taiwanese “aerosol box”
This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic
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