134 research outputs found

    Evaluating spectral radiances simulated by the HadGEM2 global climate model using longwave satellite measurements

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    A 'model-to-radiance' comparison of simulated brightness temperatures and radiances from the Hadley Centre Global Environmental Model 2 (HadGEM2-A) with longwave measurements from the High Resolution Infrared Radiation Sounder/4 (HIRS/4) and the Infrared Atmospheric Sounding Interfermeter (IASI) onboard the MetOp-A satellite is presented for all-sky and clear-sky global means. The fast Radiative Transfer model for TOVS 10 (RTTOV-10) is applied to HadGEM2 output to simulate observational-equivalent data. The results are compared with corresponding broadband analyses. A method is developed to extend hyperspectral IASI radiances to cover the whole outgoing terrestrial spectrum, in order to identify any compensating biases, and explore wavebands in the unobserved Far Infrared (FIR) region. For the all-sky HIRS analysis, the model overestimates brightness temperatures in the atmospheric window region with the greatest biases over areas associated with deep convective cloud. In contrast to many global climate models, much smaller clear-sky biases are found indicating that model clouds are the dominating source of error. Simulated values in upper atmospheric CO2 channels approximate observations better as a result of compensating cold biases at the poles and warm biases at lower latitudes, due to a poor representation of the Brewer Dobson circulation in the 38 level 'low-top' configuration of the model. Simulated all and clear-sky outgoing longwave radiation evaluated against the Clouds and the Earth's Radiant Energy System (CERES) and HIRS OLR products reveal good agreement, in part due to cancellation of positive and negative biases. Through physical arguments relating to the spectral energy balance within a cloud, it is suggested that broadband agreement could be the result of a balance between positive window biases and unseen negative biases originating from the water vapour rotational band in the FIR (not sampled by HIRS). Simple sensitivity tests show that dramatically altering existing cloud properties has little effect on the prominent window biases, however raising clouds a maximum of 5 atmospheric levels minimises the error in cloud contaminated channels, due to the introduction of spatially compensating errors. Sensitivities to the way ice clouds are parameterised in RTTOV-10 display a range of up to 2.5 K in window channels but absolute biases still exceed 3 K for all choices. Because of the lack of satellite based FIR observations due to a technological gap in the spectral region, an algorithm is created to 'fill in' the available data. Correlations between selected IASI channels and simulated unobserved wavelengths in the far infrared are used to estimate radiances between 25.25 - 644.75 cm-1 at 0.5 cm-1 intervals. The same method is used in the 2760 - 3000 cm-1 region. The spectrum is validated by comparing the Integrated Nadir Longwave Radiance (INLR) product (spanning the whole 25.25 - 3000 cm-1 range) with the corresponding broadband measurements from the Clouds and the Earth's Radiant Energy System (CERES) instrument on the Terra and Aqua satellites at simultaneous nadir overpasses, revealing mean differences of 0.3 Wm-2sr-1 (0.5% relative difference) lower for IASI relative to CERES and significantly lower biases in nighttime only scenes. Averaged global data over a single month produces mean differences of about 1 Wm-2sr-1 in both the all and the clear-sky (1.2% relative difference). The new high resolution spectrum is presented for global mean clear and total skies where the far infrared is shown to contribute 44% and 47% to the total OLR respectively, which is consistent with previous estimates. In terms of spectral cloud radiative forcing, the FIR contributes 19% and in some subtropical instances appears to be negative, results that would go un-observed with a traditional broadband analysis. The equivalent complete IASI OLR model product is simulated from GCM data using RTTOV-10. The same process of applying predictors to the satellite measurements is applied to the model simulated radiances, with appropriate modifications, to produce a directly comparable model product. Annual mean all-sky radiances are still greatly overestimated at all wavenumbers with a total radiance bias of 4.52 Wm-2 across the whole range. Compensating negative biases outside of the HIRS coverage that were hypothesised are absent, with the far infrared contributing to the overall bias rather than cancelling it. Equivalent clear-sky biases are much lower overall at 0.39 Wm-2, in part due to spectral and spatial cancellation of errors. A flux-to-flux comparison is enabled by estimating the spatial distribution of anisotropic factors, using collated HIRS OLR fluxes and IASI OLR radiances, which yields global mean model fluxes in excess of 12 Wm-2 higher than observations in the all-sky. The difference between this and the fluxes calculated using the climate model's broadband radiation code (Edward-Slingo) are around 10 Wm-2 which is outside the range of uncertainty in the method used to estimate the flux. However, it is discussed that tuning of the climate model's broadband code to known flux values is a required practice to ensure global energy budgets balance but can produce inaccurate parameterised variables. An equivalent analysis adjusting the ice cloud parametrisation to reflect the radiances that have the biggest differences to the original configuration selected showed a bias reduction of 4.5 Wm-2, which is still not enough to completely explain its size, suggesting the existence of residual cloud problems. Finally, it is suggested that the way forward in separating and constraining cloud errors, in both radiative transfer codes, is a rigorous process of testing them with observation cloud properties and reanalysis data as inputs

    What are the long-term holistic health consequences of COVID-19 among survivors? An umbrella systematic review.

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    Many people who have survived COVID-19 have experienced negative persistent impacts on health. Impacts on health have included persistent respiratory symptoms, decreased quality of life, fatigue, impaired functional capacity, memory deficits, psychological impacts, and difficulties in returning to paid employment. Evidence is yet to be pooled to inform future directions in research and practice, to determine the physical, psychological, social, and spiritual impacts of the illness which extend beyond the acute phase of COVID-19 survivors. This umbrella review (review of systematic reviews) critically synthesized physical (including abnormal laboratory parameters), psychological, social, and spiritual impacts which extended beyond the acute phase of COVID-19 survivors. The search strategy was based on the sample, phenomena of interest, design, evaluation, research model and all publications were double screened independently by four review authors for the eligibility criteria. Data extraction and quality assessment were conducted in parallel independently. Eighteen systematic reviews were included, which represented a total of 493 publications. Sample sizes ranged from n = 15 to n = 44 799 with a total of n = 295 455 participants. There was incomplete reporting of several significant data points including the description of the severe acute respiratory syndrome coronavirus 2 variant, COVID-19 treatments, and key clinical and demographic data. A number of physical, psychological, and social impacts were identified for individuals grappling with post-COVID condition. The long term sequalae of acute COVID-19 and size of the problem is only beginning to emerge. Further investigation is needed to ensure that those affected by post-COVID condition have their informational, spiritual, psychological, social, and physical needs met in the future

    Set up and assessment of progression criteria for internal pilots:the Brushing RemInder 4 Good oral HealTh (BRIGHT) trial example

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    Background Dental caries is common in young people and has wide-ranging ramifications for health and quality of life. Text messaging interventions show promise as a means to promote oral health behaviour change among young people. This paper reports the internal pilot of the Brushing RemInder 4 Good oral HealTh (BRIGHT) trial, which is evaluating an intervention comprising an oral health classroom lesson and text messages about toothbrushing, on caries in young people. Pilot trial objectives were to evaluate the feasibility and appropriateness of recruitment and data collection methods, the randomisation strategy, and intervention delivery against progression criteria for the main trial. Methods This is an internal pilot trial embedded within an assessor-blinded, two-arm, cluster randomised controlled trial. Participants were pupils aged 11–13 years (in year 7/S1 or year 8/S2) in secondary schools in England, Scotland, and Wales with above average pupil eligibility for free school meals. Following completion of pupil baseline questionnaires and dental assessments, year groups within schools were randomised to the intervention or control arm. Approximately 12 weeks later, participants completed a follow-up questionnaire, which included questions about sources of oral health advice to assess intervention contamination between year groups. At the end of the pilot phase, trial conduct was reviewed against pre-specified progression criteria. Results Ten schools were recruited for the pilot, with 20 year groups and 1073 pupils randomised (average of 54 pupils per year group). Data collection methods and intervention delivery were considered feasible, the response rate to the follow-up questionnaire was over 80%, there was an indication of a positive effect on self-reported toothbrushing, and interest was obtained from 80% of the schools required for the main trial. Despite partial intervention contamination between year groups, within-school randomisation at the level of the year-group was considered appropriate for the main trial, and the sample size was revised to account for partial contamination. Facilitators and barriers to recruitment and data collection were identified and strategies refined for the main trial. Conclusions Progression to the main trial of BRIGHT, with some design refinements, was concluded. The internal pilot was an efficient way to determine trial feasibility and optimise trial processes

    The benefit of evolving multidisciplinary care in ALS: a diagnostic cohort survival comparison

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    BACKGROUND Care for people with amyotrophic lateral sclerosis (ALS) has altered at King's College Hospital over the last 20 years. The clinic has been a multidisciplinary, specialist, tertiary referral centre since 1995 with a large team with integrated palliative and respiratory care since 2006. We hypothesised that these changes would improve survival. METHODS In this retrospective observational study, patients diagnosed with El Escorial definite, probable and possible ALS between 1995-1998 and 2008-2011 were followed up. The primary outcome measure was a chi-square test for the proportion of each cohort surviving. Kaplan-Meier survival analysis and Cox multivariate regression were secondary analyses. RESULTS There was low reporting of some interventions. Five hundred and forty-seven people were included. Survival between the cohorts was significantly different (p = 0.022) with a higher proportion surviving during 2008-2011. Survival time was 21.6 (95% CI 19.2-24.0) months in the 2008-2011 cohort compared to 19.2 years (15.6-21.6) in the 1995-1998 cohort (log rank p = 0.018). Four hundred and ninety-three cases were included in the Cox regression. Diagnostic cohort was a significant predictor variable (HR 0.79 (0.64-0.97) p = 0.023). CONCLUSIONS These results support the hypothesis that integrated specialist clinics with multidisciplinary input improve survival in ALS

    Air quality and mental health: evidence, challenges and future directions

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    Background: Poor air quality is associated with poor health. Little attention is given to the complex array of environmental exposures and air pollutants that affect mental health during the life course. // Aims: We gather interdisciplinary expertise and knowledge across the air pollution and mental health fields. We seek to propose future research priorities and how to address them. // Method: Through a rapid narrative review, we summarise the key scientific findings, knowledge gaps and methodological challenges. // Results: There is emerging evidence of associations between poor air quality, both indoors and outdoors, and poor mental health more generally, as well as specific mental disorders. Furthermore, pre-existing long-term conditions appear to deteriorate, requiring more healthcare. Evidence of critical periods for exposure among children and adolescents highlights the need for more longitudinal data as the basis of early preventive actions and policies. Particulate matter, including bioaerosols, are implicated, but form part of a complex exposome influenced by geography, deprivation, socioeconomic conditions and biological and individual vulnerabilities. Critical knowledge gaps need to be addressed to design interventions for mitigation and prevention, reflecting ever-changing sources of air pollution. The evidence base can inform and motivate multi-sector and interdisciplinary efforts of researchers, practitioners, policy makers, industry, community groups and campaigners to take informed action. // Conclusions: There are knowledge gaps and a need for more research, for example, around bioaerosols exposure, indoor and outdoor pollution, urban design and impact on mental health over the life course

    Surgery versus conservative management of stable thoracolumbar fracture : the PRESTO feasibility RCT

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    BACKGROUND: There is informal consensus that simple compression fractures of the body of the thoracolumbar vertebrae between the 10th thoracic vertebra and the second lumbar vertebra without neurological complications can be managed conservatively and that obvious unstable fractures require surgical fixation. However, there is a zone of uncertainty about whether surgical or conservative management is best for stable fractures. OBJECTIVES: To assess the feasibility of a definitive randomised controlled trial comparing surgical fixation with initial conservative management of stable thoracolumbar fractures without spinal cord injury. DESIGN: External randomised feasibility study, qualitative study and national survey. SETTING: Three NHS hospitals. METHODS: A feasibility randomised controlled trial using block randomisation, stratified by centre and type of injury (high- or low-energy trauma) to allocate participants 1 : 1 to surgery or conservative treatment; a costing analysis; a national survey of spine surgeons; and a qualitative study with clinicians, recruiting staff and patients. PARTICIPANTS: Adults aged ≥ 16 years with a high- or low-energy fracture of the body of a thoracolumbar vertebra between the 10th thoracic vertebra and the second lumbar vertebra, confirmed by radiography, computerised tomography or magnetic resonance imaging, with at least one of the following: kyphotic angle > 20° on weight-bearing radiographs or > 15° on a supine radiograph or on computerised tomography; reduction in vertebral body height of 25%; a fracture line propagating through the posterior wall of the vertebra; involvement of two contiguous vertebrae; or injury to the posterior longitudinal ligament or annulus in addition to the body fracture. INTERVENTIONS: Surgical fixation: open spinal surgery (with or without spinal fusion) or minimally invasive stabilisation surgery. Conservative management: mobilisation with or without a brace. MAIN OUTCOME MEASURE: Recruitment rate (proportion of eligible participants randomised). RESULTS: Twelve patients were randomised (surgery, n = 8; conservative, n = 4). The proportion of eligible patients recruited was 0.43 (95% confidence interval 0.24 to 0.63) over a combined total of 30.7 recruitment months. Of 211 patients screened, 28 (13.3%) fulfilled the eligibility criteria. Patients in the qualitative study (n = 5) expressed strong preferences for surgical treatment, and identified provision of information about treatment and recovery and when and how they are approached for consent as important. Nineteen surgeons and site staff participated in the qualitative study. Key themes were the lack of clinical consensus regarding the implementation of the eligibility criteria in practice and what constitutes a stable fracture, alongside lack of equipoise regarding treatment. Based on the feasibility study eligibility criteria, 77% (50/65) and 70% (46/66) of surgeons participating in the survey were willing to randomise for high- and low-energy fractures, respectively. LIMITATIONS: Owing to the small number of participants, there is substantial uncertainty around the recruitment rate. CONCLUSIONS: A definitive trial is unlikely to be feasible currently, mainly because of the small number of patients meeting the eligibility criteria. The recruitment and follow-up rates were slightly lower than anticipated; however, there is room to increase these based on information gathered and the support within the surgical community for a future trial. FUTURE WORK: Development of consensus regarding the population of interest for a trial. TRIAL REGISTRATION: Current Controlled Trials ISRCTN12094890. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 62. See the NIHR Journals Library website for further project information

    Impact of deploying multiple point-of-care tests with a 'sample first' approach on a sexual health clinical care pathway. A service evaluation.

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    OBJECTIVES: To assess clinical service value of STI point-of-care test (POCT) use in a 'sample first' clinical pathway (patients providing samples on arrival at clinic, before clinician consultation). Specific outcomes were: patient acceptability; whether a rapid nucleic acid amplification test (NAAT) for Chlamydia trachomatis/Neisseria gonorrhoeae (CT/NG) could be used as a POCT in practice; feasibility of non-NAAT POCT implementation for Trichomonas vaginalis (TV) and bacterial vaginosis (BV); impact on patient diagnosis and treatment. METHODS: Service evaluation in a south London sexual health clinic. Symptomatic female and male patients and sexual contacts of CT/NG-positive individuals provided samples for diagnostic testing on clinic arrival, prior to clinical consultation. Tests included routine culture and microscopy; CT/NG (GeneXpert) NAAT; non-NAAT POCTs for TV and BV. RESULTS: All 70 (35 males, 35 females) patients approached participated. The 'sample first' pathway was acceptable, with >90% reporting they were happy to give samples on arrival and receive results in the same visit. Non-NAAT POCT results were available for all patients prior to leaving clinic; rapid CT/NG results were available for only 21.4% (15/70; 5 males, 10 females) of patients prior to leaving clinic. Known negative CT/NG results led to two females avoiding presumptive treatment, and one male receiving treatment directed at possible Mycoplasma genitalium infection causing non-gonococcal urethritis. Non-NAAT POCTs detected more positives than routine microscopy (TV 3 vs 2; BV 24 vs 7), resulting in more patients receiving treatment. CONCLUSIONS: A 'sample first' clinical pathway to enable multiple POCT use was acceptable to patients and feasible in a busy sexual health clinic, but rapid CT/NG processing time was too long to enable POCT use. There is need for further development to improve test processing times to enable POC use of rapid NAATs

    Air quality and mental health: evidence, challenges and future directions

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    Background: Poor air quality is associated with poor health. Little attention is given to the complex array of environmental exposures and air pollutants that affect mental health during the life course. Aims: We gather interdisciplinary expertise and knowledge across the air pollution and mental health fields. We seek to propose future research priorities and how to address them. Method: Through a rapid narrative review, we summarise the key scientific findings, knowledge gaps and methodological challenges. Results: There is emerging evidence of associations between poor air quality, both indoors and outdoors, and poor mental health more generally, as well as specific mental disorders. Furthermore, pre-existing long-term conditions appear to deteriorate, requiring more healthcare. Evidence of critical periods for exposure among children and adolescents highlights the need for more longitudinal data as the basis of early preventive actions and policies. Particulate matter, including bioaerosols, are implicated, but form part of a complex exposome influenced by geography, deprivation, socioeconomic conditions and biological and individual vulnerabilities. Critical knowledge gaps need to be addressed to design interventions for mitigation and prevention, reflecting ever-changing sources of air pollution. The evidence base can inform and motivate multi-sector and interdisciplinary efforts of researchers, practitioners, policy makers, industry, community groups and campaigners to take informed action. Conclusions: There are knowledge gaps and a need for more research, for example, around bioaerosols exposure, indoor and outdoor pollution, urban design and impact on mental health over the life course.Natural Environment Research Council (NERC): NE/V002171/1; Engineering and Physical Sciences Research Council (EPSRC): EP/V052462/1; EP/W001411/1; EP/T003189/

    Safety and Efficacy of the NVX-CoV2373 Coronavirus Disease 2019 Vaccine at Completion of the Placebo-Controlled Phase of a Randomized Controlled Trial

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    Acknowledgements The study and article were funded by Novavax. We would like to thank all the study participants for their commitment to this study. We also acknowledge the investigators and their study teams for their hard work and dedication. In addition, we would like to thank the National Institute for Health Research, representatives from the Department of Health and Social Care laboratories and NHS Digital and the members of the UK Vaccine Task Force. Editorial support was provided by Kelly Cameron of Ashfield MedComms, an Inizio company Funding This work was funded by Novavax, and the sponsor had primary responsibility for study design, study vaccines, protocol development, study monitoring, data management, and statistical analyses. All authors reviewed and approved the manuscript before submission. LF reports a position as a prior full-time employee, now contractor to Novavax re-imbursed hourly for work performed on this study and in analyses and drafting this report. IC reports providing medical writing support for this work as an employee of NovavaxPeer reviewedPublisher PD
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