7,241 research outputs found
Prioritising older individuals for COVID-19 booster vaccination leads to optimal public health outcomes in a range of socio-economic settings
The rapid development of vaccines against SARS-CoV-2 altered the course of the COVID-19 pandemic. In most countries, vaccinations were initially targeted at high-risk populations, including older individuals and healthcare workers. Now, despite substantial infection- and vaccine-induced immunity in host populations worldwide, waning immunity and the emergence of novel variants continue to cause significant waves of infection and disease. Policy makers must determine how to deploy booster vaccinations, particularly when constraints in vaccine supply, delivery and cost mean that booster vaccines cannot be administered to everyone. A key question is therefore whether older individuals should again be prioritised for vaccination, or whether alternative strategies (e.g. offering booster vaccines to the individuals who have most contacts with others and therefore drive infection) can instead offer indirect protection to older individuals. Here, we use mathematical modelling to address this question, considering SARS-CoV-2 transmission in a range of countries with different socio-economic backgrounds. We show that the population structures of different countries can have a pronounced effect on the impact of booster vaccination, even when identical booster vaccination targeting strategies are adopted. However, under the assumed transmission model, prioritising older individuals for booster vaccination consistently leads to the most favourable public health outcomes in every setting considered. This remains true for a range of assumptions about booster vaccine supply and timing, and for different assumed policy objectives of booster vaccination
Predicting illness progression for children with lower respiratory infections (LRTI) presenting to primary care
Background Antibiotics are commonly prescribed for children with lower respiratory tract infections (LRTIs), fuelling antibiotic resistance, and there are few prognostic tools available to inform management. Aim To externally validate an existing prognostic model (STARWAVe) to identify children at low risk of illness progression, and if model performance was limited to develop a new internally validated prognostic model. Design and setting Prospective cohort study with a nested trial in a primary care setting. Method Children aged 6 months to 12 years presenting with uncomplicated LRTI were included in the cohort. Children were randomised to receive amoxicillin 50 mg/kg per day for 7 days or placebo, or if not randomised they participated in a parallel observational study to maximise generalisability. Baseline clinical data were used to predict adverse outcome (illness progression requiring hospital assessment). Results A total of 758 children participated (n= 432 trial, n= 326 observational). For predicting illness progression the STARWAVe prognostic model had moderate performance (area under the receiver operating characteristic [AUROC] 0.66, 95% confidence interval [CI] = 0.50 to 0.77), but a new, internally validated model (seven items: baseline severity; respiratory rate; duration of prior illness; oxygen saturation; sputum or a rattly chest; passing urine less often; and diarrhoea) had good discrimination (bootstrapped AUROC 0.83, 95% CI = 0.74 to 0.92) and calibration. A three-item model (respiratory rate; oxygen saturation; and sputum or a rattly chest) also performed well (AUROC 0.81, 95% CI = 0.70 to 0.91), as did a score (ranging from 19 to 102) derived from coefficients of the model (AUROC 0.78, 95% CI = 0.67 to 0.88): a score of <70 classified 89% (n= 600/674) of children having a low risk (<5%) of progression of illness. Conclusion A simple three-item prognostic score could be useful as a tool to identify children with LRTI who are at low risk of an adverse outcome and to guide clinical management.</p
Non Degenerate Dual Atomic Parametric Amplifier: Entangled Atomic Fields
In this paper, we investigate the dynamics of two coupled quantum degenerate
atomic fields (BEC) interacting with two classical optical fields in the
nonlinear atom optics regime. Two photon interaction produces entangled
atom-atom pairs which exhibit nonclassical correlations. Since the system
involves the creation of two correlated atom pairs, we call it the
nondegenerate dual atomic parametric amplifier.Comment: 5 figure
Impacts and effects of ocean warming on intertidal rocky habitats.
• Intertidal rocky habitats comprise over 50% of the shorelines of the world, supporting a diversity of marine life and providing extensive ecosystem services worth in the region of US$ 5-10 trillion per year. • They are valuable indicators of the impacts of climate change on the wider marine environment and ecosystems. • Changes in species distributions, abundance and phenology have already been observed around the world in response to recent rapid climate change. • Species-level responses will have considerable ramifications for the structure of communities and trophic interactions, leading to eventual changes in ecosystem functioning (e.g. less primary producing canopy-forming algae in the North-east Atlantic). • Whilst progress is made on the mitigation1 required to achieve goals of a lower-carbon world, much can be done to enhance resilience to climate change. Managing the multitude of other interactive impacts on the marine environment, over which society has greater potential control (e.g. overfishing, invasive non-native species, coastal development, and pollution), will enable adaptation1 in the short and medium term of the next 5-50 years
Wall-Crossing in Coupled 2d-4d Systems
We introduce a new wall-crossing formula which combines and generalizes the
Cecotti-Vafa and Kontsevich-Soibelman formulas for supersymmetric 2d and 4d
systems respectively. This 2d-4d wall-crossing formula governs the
wall-crossing of BPS states in an N=2 supersymmetric 4d gauge theory coupled to
a supersymmetric surface defect. When the theory and defect are compactified on
a circle, we get a 3d theory with a supersymmetric line operator, corresponding
to a hyperholomorphic connection on a vector bundle over a hyperkahler space.
The 2d-4d wall-crossing formula can be interpreted as a smoothness condition
for this hyperholomorphic connection. We explain how the 2d-4d BPS spectrum can
be determined for 4d theories of class S, that is, for those theories obtained
by compactifying the six-dimensional (0,2) theory with a partial topological
twist on a punctured Riemann surface C. For such theories there are canonical
surface defects. We illustrate with several examples in the case of A_1
theories of class S. Finally, we indicate how our results can be used to
produce solutions to the A_1 Hitchin equations on the Riemann surface C.Comment: 170 pages, 45 figure
CHIMPS: the <sup>13</sup>CO/C<sup>18</sup>O (<i>J</i> = 3 → 2) Heterodyne Inner Milky Way Plane Survey
We present the 13CO/C18O (J = 3 → 2) Heterodyne Inner Milky Way Plane Survey (CHIMPS) which has been carried out using the Heterodyne Array Receiver Program on the 15 m James Clerk Maxwell Telescope (JCMT) in Hawaii. The high-resolution spectral survey currently covers |b| ≤ 0.5° and 28° ≲ l ≲ 46°, with an angular resolution of 15 arcsec in 0.5 km s-1 velocity channels. The spectra have a median rms of ˜0.6 K at this resolution, and for optically thin gas at an excitation temperature of 10 K, this sensitivity corresponds to column densities of NH2 ˜ 3 × 1020 cm-2 and NH2 ˜ 4 × 1021 cm-2 for 13CO and C18O, respectively. The molecular gas that CHIMPS traces is at higher column densities and is also more optically thin than in other publicly available CO surveys due to its rarer isotopologues, and thus more representative of the three-dimensional structure of the clouds. The critical density of the J = 3 → 2 transition of CO is ≳104 cm-3 at temperatures of ≤20 K, and so the higher density gas associated with star formation is well traced. These data complement other existing Galactic plane surveys, especially the JCMT Galactic Plane Survey which has similar spatial resolution and column density sensitivity, and the Herschel infrared Galactic Plane Survey. In this paper, we discuss the observations, data reduction and characteristics of the survey, presenting integrated-emission maps for the region covered. Position-velocity diagrams allow comparison with Galactic structure models of the Milky Way, and while we find good agreement with a particular four-arm model, there are some significant deviations
A Peculiar Family of Jupiter Trojans: the Eurybates
The Eurybates family is a compact core inside the Menelaus clan, located in
the L4 swarm of Jupiter Trojans. Fornasier et al. (2007) found that this family
exhibits a peculiar abundance of spectrally flat objects, similar to
Chiron-like Centaurs and C-type main belt asteroids. On the basis of the
visible spectra available in literature, Eurybates family's members seemed to
be good candidates for having on their surfaces water/water ice or aqueous
altered materials. To improve our knowledge of the surface composition of this
peculiar family, we carried out an observational campaign at the Telescopio
Nazionale Galileo (TNG), obtaining near-infrared spectra of 7 members. Our data
show a surprisingly absence of any spectral feature referable to the presence
of water, ices or aqueous altered materials on the surface of the observed
objects. Models of the surface composition are attempted, evidencing that
amorphous carbon seems to dominate the surface composition of the observed
bodies and some amount of silicates (olivine) could be present.Comment: 23 pages, 2 figures, paper accepted for publication in Icaru
Implementing early rehabilitation and mobilisation for children in UK paediatric intensive care units: the PERMIT feasibility study
Background: Early rehabilitation and mobilisation encompass patient-tailored interventions, delivered within intensive care, but there are few studies in children and young people within paediatric intensive care units. Objectives: To explore how healthcare professionals currently practise early rehabilitation and mobilisation using qualitative and quantitative approaches; co-design the Paediatric Early Rehabilitation and Mobilisation during InTensive care manual of early rehabilitation and mobilisation interventions, with primary and secondary patient-centred outcomes; explore feasibility and acceptability of implementing the Paediatric Early Rehabilitation and Mobilisation during InTensive care manual within three paediatric intensive care units. Design: Mixed-methods feasibility with five interlinked studies (scoping review, survey, observational study, codesign workshops, feasibility study) in three phases. Setting: United Kingdom paediatric intensive care units. Participants: Children and young people aged 0–16 years remaining within paediatric intensive care on day 3, their parents/guardians and healthcare professionals. Interventions: In Phase 3, unit-wide implementation of manualised early rehabilitation and mobilisation. Main outcome measures: Phase 1 observational study: prevalence of any early rehabilitation and mobilisation on day 3. Phase 3 feasibility study: acceptability of early rehabilitation and mobilisation intervention; adverse events; acceptability of study design; acceptability of outcome measures. Data sources: Searched Excerpta Medica Database, Cumulative Index to Nursing and Allied Health Literature, MEDLINE, PEDro, Open grey and Cochrane CENTRAL databases. Review methods: Narrative synthesis. Results: In the scoping review we identified 36 full-text reports evaluating rehabilitation initiated within 7 days of paediatric intensive care unit admission, outlining non-mobility and mobility early rehabilitation and mobilisation interventions from 24 to 72 hours and delivered twice daily. With the survey, 124/191 (65%) responded from 26/29 (90%) United Kingdom paediatric intensive care units; the majority considered early rehabilitation and mobilisation a priority. The observational study followed 169 patients from 15 units; prevalence of any early rehabilitation and mobilisation on day 3 was 95.3%. We then developed a manualised early rehabilitation and mobilisation intervention informed by current evidence, experience and theory. All three sites implemented the Paediatric Early Rehabilitation and Mobilisation during InTensive care manual successfully, recruited to target (30 patients recruited) and followed up the patients until day 30 or discharge; 21/30 parents consented to complete additional outcome measures. Limitations: The findings represent the views of National Health Service staff but may not be generalisable. We were unable to conduct workshops and interviews with children, young people and parents to support the Paediatric Early Rehabilitation and Mobilisation during InTensive care manual development due to pandemic restrictions. Conclusions: A randomised controlled trial is recommended to assess the effectiveness of the manualised early rehabilitation and mobilisation intervention
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