186 research outputs found
Safety-netting in routine primary care consultations:an observational study using video-recorded UK consultations
Constraining the Tilt of the Milky Way's Dark Matter Halo with the Sagittarius Stream
Recent studies have suggested that the Milky Way (MW)'s Dark Matter (DM) halo
may be significantly tilted with respect to its central stellar disk, a feature
that might be linked to its formation history. In this work, we demonstrate a
method of constraining the orientation of the minor axis of the DM halo using
the angle and frequency variables. This method is complementary to other
traditional techniques, such as orbit fitting. We first test the method using a
simulated tidal stream evolving in a realistic environment inside an MW-mass
host from the FIRE cosmological simulation, showing that the theoretical
description of a stream in the action-angle-frequency formalism still holds for
a realistic dwarf galaxy stream in a cosmological potential. Utilizing the
slopes of the line in angle and frequency space, we show that the correct
rotation frame yields a minimal slope difference, allowing us to put a
constraint on the minor axis location. Finally, we apply this method to the
Sagittarius stream's leading arm. We report that the MW's DM halo is oblate
with the flattening parameter in the potential and the minor
axis pointing toward . Our constraint on the minor
axis location is weak and disagrees with the estimates from other works; we
argue that the inconsistency can be attributed in part to the observational
uncertainties and in part to the influence of the Large Magellanic Cloud.Comment: 16 pages, 12 figure
Continuity of care as a predictor of ongoing frequent attendance in primary care:a retrospective cohort study
On the stability of tidal streams in action space
In the Gaia era it is increasingly apparent that traditional static,
parameterized models are insufficient to describe the mass distribution of our
complex, dynamically evolving Milky Way (MW). In this work, we compare
different time-evolving and time-independent representations of the
gravitational potentials of simulated MW-mass galaxies from the FIRE-2 suite of
cosmological baryonic simulations. Using these potentials, we calculate actions
for star particles in tidal streams around three galaxies with varying merger
histories at each snapshot from 7 Gyr ago to the present day. We determine the
action-space coherence preserved by each model using the Kullback-Leibler
Divergence to gauge the degree of clustering in actions and the relative
stability of the clusters over time. We find that all models produce a
clustered action space for simulations with no significant mergers. However, a
massive (mass ratio prior to infall more similar than 1:8) interacting galaxy
not present in the model will result in mischaracterized orbits for stars most
affected by the interaction. The locations of the action space clusters (i.e.
the orbits of the stream stars) are only preserved by the time-evolving model,
while the time-independent models can lose significant amounts of information
as soon as 0.5--1 Gyr ago, even if the system does not undergo a significant
merger. Our results imply that reverse-integration of stream orbits in the MW
using a fixed potential is likely to give incorrect results if integrated
longer than 0.5 Gyr into the past
Development of a tool for coding safety-netting behaviours in primary care:a mixed-methods study using existing UK consultation recordings
LMC-driven anisotropic boosts in stream--subhalo interactions
Dark Matter (DM) subhalos are predicted to perturb stellar streams; stream
morphologies and dynamics can constrain the mass distribution of subhalos.
Using FIRE-2 simulations of Milky Way-mass galaxies, we show that presence of a
Large Magellanic Cloud (LMC)--analog significantly changes stream-subhalo
encounter rates. Three key factors drive these changes. First, the LMC--analog
brings in many subhalos, increasing encounter rates for streams near the
massive satellite by up to 20--40%. Second, the LMC--analog displaces the host
from its center-of-mass (inducing reflex motion), causing a north-south
asymmetry in the density and radial velocity distribution of subhalos. This
asymmetry results in encounter rates varying by 50--70% across the sky at the
same distance. Finally, the LMC--mass satellite induces a density wake in the
host's DM halo, further boosting the encounter rates near the LMC--analog. We
also explore the influence of stream orbital properties, finding a 50% increase
in encounters for streams moving retrograde to the LMC--analog's orbit in the
opposite hemisphere. The dependence of encounter rates on stream location and
orbit has important implications for where to search for new streams with spurs
and gaps in the Milky Way.Comment: 26 pages, 15 figures, submitted to AP
Comparison of lotions, creams, gels and ointments for the treatment of childhood eczema: The BEE RCT
BackgroundEmollients are recommended for children with eczema (atopic eczema/dermatitis). A lack of head-to-head comparisons of the effectiveness and acceptability of the different types of emollients has resulted in a ‘trial and error’ approach to prescribing.ObjectiveTo compare the effectiveness and acceptability of four commonly used types of emollients for the treatment of childhood eczema.DesignFour group, parallel, individually randomised, superiority randomised clinical trials with a nested qualitative study, completed in 2021. A purposeful sample of parents/children was interviewed at ≈ 4 and ≈ 16 weeks.SettingPrimary care (78 general practitioner surgeries) in England.ParticipantsChildren aged between 6 months and 12 years with eczema, of at least mild severity, and with no known sensitivity to the study emollients or their constituents.InterventionsStudy emollients sharing the same characteristics in the four types of lotion, cream, gel or ointment, alongside usual care, and allocated using a web-based randomisation system. Participants were unmasked and the researcher assessing the Eczema Area Severity Index scores was masked.Main outcome measuresThe primary outcome was Patient-Oriented Eczema Measure scores over 16 weeks. The secondary outcomes were Patient-Oriented Eczema Measure scores over 52 weeks, Eczema Area Severity Index score at 16 weeks, quality of life (Atopic Dermatitis Quality of Life, Child Health Utility-9 Dimensions and EuroQol-5 Dimensions, five-level version, scores), Dermatitis Family Impact and satisfaction levels at 16 weeks.ResultsA total of 550 children were randomised to receive lotion (analysed for primary outcome 131/allocated 137), cream (137/140), gel (130/135) or ointment (126/138). At baseline, 86.0% of participants were white and 46.4% were female. The median (interquartile range) age was 4 (2–8) years and the median Patient-Oriented Eczema Measure score was 9.3 (SD 5.5). There was no evidence of a difference in mean Patient-Oriented Eczema Measure scores over the first 16 weeks between emollient types (global p = 0.765): adjusted Patient-Oriented Eczema Measure pairwise differences – cream–lotion 0.42 (95% confidence interval –0.48 to 1.32), gel–lotion 0.17 (95% confidence interval –0.75 to 1.09), ointment–lotion –0.01 (95% confidence interval –0.93 to 0.91), gel–cream –0.25 (95% confidence interval –1.15 to 0.65), ointment–cream –0.43 (95% confidence interval –1.34 to 0.48) and ointment–gel –0.18 (95% confidence interval –1.11 to 0.75). There was no effect modification by parent expectation, age, disease severity or the application of UK diagnostic criteria, and no differences between groups in any of the secondary outcomes. Median weekly use of allocated emollient, non-allocated emollient and topical corticosteroids was similar across groups. Overall satisfaction was highest for lotions and gels. There was no difference in the number of adverse reactions and there were no significant adverse events. In the nested qualitative study (n = 44 parents, n = 25 children), opinions about the acceptability of creams and ointments varied most, yet problems with all types were reported. Effectiveness may be favoured over acceptability. Parents preferred pumps and bottles over tubs and reported improved knowledge about, and use of, emollients as a result of taking part in the trial.LimitationsParents and clinicians were unmasked to allocation. The findings may not apply to non-study emollients of the same type or to children from more ethnically diverse backgrounds.ConclusionsThe four emollient types were equally effective. Satisfaction with the same emollient types varies, with different parents/children favouring different ones. Users need to be able to choose from a range of emollient types to find one that suits them.Future workFuture work could focus on how best to support shared decision-making of different emollient types and evaluations of other paraffin-based, non-paraffin and ‘novel’ emollients.Trial registrationThis trial is registered as ISRCTN84540529 and EudraCT 2017-000688-34.FundingThis project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (HTA 15/130/07) and will be published in full in Health Technology Assessment; Vol. 27, No. 19. See the NIHR Journals Library website for further project information
Action 3:30R: Results of a cluster randomised feasibility study of a revised teaching assistant-led extracurricular physical activity intervention for 8 to 10 year olds
Many children are not sufficiently physically active. We conducted a cluster-randomised feasibility trial of a revised after-school physical activity (PA) programme delivered by trained teaching assistants (TAs) to assess the potential evidence of promise for increasing moderate-to-vigorous physical activity (MVPA). Participants (n = 335) aged 8–10 years were recruited from 12 primary schools in South West England. Six schools were randomised to receive the intervention and six acted as non-intervention controls. In intervention schools, TAs were trained to deliver an after-school programme for 15 weeks. The difference in mean accelerometer-assessed MVPA between intervention and control schools was assessed at follow-up (T1). The cost of programme delivery was estimated. Two schools did not deliver the intervention, meaning four intervention and six control schools were analysed at T1. There was no evidence for a difference in MVPA at T1 between intervention and control groups. Programme delivery cost was estimated at £2.06 per pupil per session. Existing provision in the 12 schools cost £5.91 per pupil per session. Action 3:30 was feasible to deliver and considerably cheaper than existing after-school provision. No difference in weekday MVPA was observed at T1 between the two groups, thus progression to a full trial is not warranted
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