A High Performance EO Small Satellite Platform (SSTL-300)

This paper describes a new high performance Earth Observation Platform, the SSTL-300, which has been developed to provide customers with a capability that has previously only been available at much higher cost and on larger platforms. This platform offers a 7-year mission lifetime with a very high operational availability. The main payload is a very high-resolution imager (VHRI) with a panchromatic 2.5m ground sampling distance (GSD) channel and four multi-spectral channels offering 5m GSD. The imager swath is 20km in all channels. This imager is an extension of the 4m GSD imager already flying on Beijing-1, which was launched in October 2005. Additional payloads can be accommodated, such as the Medium Resolution Imager (MRI), offering lower resolution of 22m or 32m GSD in four multiple spectral bands with 300km swath width. The 32m MRI has already flown on four previous Disaster Monitoring Constellation (DMC) Missions. High performance geo-location is provided, the performance of which is dependent on the chosen subsystem options. Simultaneous imaging is possible with the VHRI and the MRI and scenes can be as long as 2000km. The image data is compressed on-board, using lossless data compression, for store-and-forward operations. Furthermore, switchable encryption is available, using the Data Encryption Standard (DES), on the TM/TC as well as switchable scrambling on payload data. Near real-time imaging &amp; down-linking is possible for a range of targets close to the ground station. A range of imaging modes are available including: strip mapping, fast response scene capture, stereo imaging, with pitch angles between 10 and 45 degrees to provide digital elevation models, and increased area coverage to provide wide-swath high-resolution imagery of up to 85km. The nominal orbit for the SSTL-300 will be sun-synchronous, with a 10.30am node to provide repeatable global coverage and good lighting conditions. The platform will orbit at approximately 700km, which provides good optimisation for single satellite and constellation revisits. On-board propulsion is included for orbit maintenance.</p

Brief intervention for alcohol misuse in people attending sexual health clinics: study protocol for a randomized controlled trial.

BACKGROUND: Over the last 30  years the number of people who drink alcohol at harmful levels has increased in many countries. There have also been large increases in rates of sexually transmitted infections. Available evidence suggests that excessive alcohol consumption and poor sexual health may be linked. The prevalence of harmful alcohol use is higher among people attending sexual health clinics than in the general population, and a third of those attending clinics state that alcohol use affects whether they have unprotected sex. Previous research has demonstrated that brief intervention for alcohol misuse in other medical settings can lead to behavioral change, but the clinical- and cost-effectiveness of this intervention on sexual behavior have not been examined. METHODS: We will conduct a two parallel-arm, randomized trial. A consecutive sample of people attending three sexual health clinics in London and willing to participate in the study will be screened for excessive alcohol consumption. Participants identified as drinking excessively will then be allocated to either active treatment (Brief Advice and referral for Brief Intervention) or control treatment (a leaflet on healthy living). Randomization will be via an independent and remote telephone randomization service and will be stratified by study clinic. Brief Advice will comprise feedback on the possible health consequences of excessive alcohol consumption, written information about alcohol and the offer of an appointment for further assessment and Brief Intervention. Follow-up data on alcohol use, sexual behavior, health related quality of life and service use will be collected by a researcher masked to allocation status six months later. The primary outcome for the study is mean weekly alcohol consumption during the previous three months, and the main secondary outcome is the proportion of participants who report unprotected sex during this period. DISCUSSION: Opportunistic intervention for excessive alcohol use has been shown to be effective in a range of medical settings. The SHEAR study will examine whether delivering such interventions in sexual health clinics results in reductions in alcohol consumption and will explore whether this is associated with changes in sexual behavior.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

COVID-19 trajectories among 57 million adults in England: a cohort study using electronic health records

BACKGROUND: Updatable estimates of COVID-19 onset, progression, and trajectories underpin pandemic mitigation efforts. To identify and characterise disease trajectories, we aimed to define and validate ten COVID-19 phenotypes from nationwide linked electronic health records (EHR) using an extensible framework. METHODS: In this cohort study, we used eight linked National Health Service (NHS) datasets for people in England alive on Jan 23, 2020. Data on COVID-19 testing, vaccination, primary and secondary care records, and death registrations were collected until Nov 30, 2021. We defined ten COVID-19 phenotypes reflecting clinically relevant stages of disease severity and encompassing five categories: positive SARS-CoV-2 test, primary care diagnosis, hospital admission, ventilation modality (four phenotypes), and death (three phenotypes). We constructed patient trajectories illustrating transition frequency and duration between phenotypes. Analyses were stratified by pandemic waves and vaccination status. FINDINGS: Among 57 032 174 individuals included in the cohort, 13 990 423 COVID-19 events were identified in 7 244 925 individuals, equating to an infection rate of 12·7% during the study period. Of 7 244 925 individuals, 460 737 (6·4%) were admitted to hospital and 158 020 (2·2%) died. Of 460 737 individuals who were admitted to hospital, 48 847 (10·6%) were admitted to the intensive care unit (ICU), 69 090 (15·0%) received non-invasive ventilation, and 25 928 (5·6%) received invasive ventilation. Among 384 135 patients who were admitted to hospital but did not require ventilation, mortality was higher in wave 1 (23 485 [30·4%] of 77 202 patients) than wave 2 (44 220 [23·1%] of 191 528 patients), but remained unchanged for patients admitted to the ICU. Mortality was highest among patients who received ventilatory support outside of the ICU in wave 1 (2569 [50·7%] of 5063 patients). 15 486 (9·8%) of 158 020 COVID-19-related deaths occurred within 28 days of the first COVID-19 event without a COVID-19 diagnoses on the death certificate. 10 884 (6·9%) of 158 020 deaths were identified exclusively from mortality data with no previous COVID-19 phenotype recorded. We observed longer patient trajectories in wave 2 than wave 1. INTERPRETATION: Our analyses illustrate the wide spectrum of disease trajectories as shown by differences in incidence, survival, and clinical pathways. We have provided a modular analytical framework that can be used to monitor the impact of the pandemic and generate evidence of clinical and policy relevance using multiple EHR sources. FUNDING: British Heart Foundation Data Science Centre, led by Health Data Research UK

International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist

Equalization of four cardiovascular risk algorithms after systematic recalibration: individual-participant meta-analysis of 86 prospective studies

Aims: There is debate about the optimum algorithm for cardiovascular disease (CVD) risk estimation. We conducted head-to-head comparisons of four algorithms recommended by primary prevention guidelines, before and after ‘recalibration’, a method that adapts risk algorithms to take account of differences in the risk characteristics of the populations being studied. Methods & Results: Using individual-participant data on 360737 participants without CVD at baseline in 86 prospective studies from 22 countries, we compared the Framingham risk score (FRS), Systematic COronary Risk Evaluation (SCORE), pooled cohort equations (PCE), and Reynolds risk score (RRS). We calculated measures of risk discrimination and calibration, and modelled clinical implications of initiating statin therapy in people judged to be at ‘high’ 10 year CVD risk. Original risk algorithms were recalibrated using the risk factor profile and CVD incidence of target populations. The four algorithms had similar risk discrimination. Before recalibration, FRS, SCORE, and PCE overpredicted CVD risk on average by 10%, 52%, and 41%, respectively, whereas RRS under-predicted by 10%. Original versions of algorithms classified 29–39% of individuals aged \u3e_40years as high risk. By contrast, recalibration reduced this proportion to 22–24% for every algorithm. We estimated that to prevent one CVD event, it would be necessary to initiate statin therapy in 44–51 such individuals using original algorithms, in contrast to 37–39 individuals with recalibrated algorithms. Conclusions: Before recalibration, the clinical performance of four widely used CVD risk algorithms varied substantially. By contrast, simple recalibration nearly equalized their performance and improved modelled targeting of preventive action to clinical need

Five Years Orbit Experience of a Small Satellite Hyperspectral Imaging Mission

This paper will summarise the results of a hyperspectral imaging mission that has now completed more than five years in orbit and is providing a wealth of data to Users across the world. The mission has demonstrated, fairly conclusively, that such sophisticated payloads can be implemented successfully on a small satellite platform. The instrument being flown is the Compact High Resolution Imaging Spectrometer (CHRIS) developed within the Optical Payload Group (OPG) of Surrey Satellite Technology Ltd. The instrument is flying on PROBA, a small agile satellite, which was launched in October 2001. The platform provides pointing in both across-track and along-track directions, for target acquisition and multi-angle observations, particularly for measurement of the Bi-directional Reflectance Distribution Function (BRDF) properties of selected targets. The instrument covers a spectral range from 400nm to 1050nm, at £11nm resolution with a spatial sampling interval at perigee of 17m and programmable band sets. The swath width imaged is 13km at perigee. Observations requests for the science mission are selected, prioritised and scheduled into feasible observations on a daily basis. The Mission continues to operate successfully even in its sixth year and demonstrates the success of the mission and the utility of the platform and instrument