l₁-gain performance analysis and positive filter design for positive discrete-time Markov jump linear systems : a linear programming approach

This paper is concerned with the l₁-gain performance analysis and positive filter design for a positive discrete-time Markov jump linear system (MJLS) by using a linear programming (LP) approach. First, by constructing a linear stochastic Lyapunov function and introducing an ‘‘equivalent’’ deterministic positive discrete-time linear system, necessary and sufficient conditions in the form of LP are derived for stochastic stability and l₁-gain performance of the positive discrete-time MJLS. Then a sufficient conditionon the existence of the desired positive l₁-gain filter is provided. The desired positive l₁-gain filter can bedesigned by solving a standard LP problem. The pest’s structured population dynamic model is employed to illustrate the effectiveness of the proposed method

Finite-time stability and stabilization for a class of nonlinear discrete-time descriptor switched systems with time-varying delay

This paper is concerned with the finite-time stability analysis and state feedback stabilization controller design fora class of nonlinear discrete-time descriptor switched systems with time-varying delay. First, by using the implicit function theorem and constructing a switched Lyapunov functional, sufficient conditions are developed which guarantee that the nonlinear discrete-time descriptor switched system with time-varying delay is regular, causal, has a unique solution in a neighborhood of the equilibrium point, and is uniformly finite-time stable. Then a delay-dependent condition on the existence of a finite-time state feedback controller is proposed. Finally, two numerical examples are given to show the effectiveness of the proposed methods

Physical coupling and decoupling of railway trains at cruising speeds: Train control and dynamics

This paper studied an emerging technology called Dynamic Coupling that to allow physical coupling and decoupling of railway trains at cruising speeds. A train controller and a train model were introduced and simulated using Parallel Computing. Two transitional gap references were designed (hyperbolic tangent and exponential). Two six-vehicle passenger trains coupling and decoupling on a revised real-world track section at 80 km/h were simulated. Results indicated that a certain negative (e.g. -5 mm) Reference Gap at Coupling Instant (RG@CI) and a positive (e.g. 2 mm) Reference Gap at Decoupling Instant (RG@DI) were recommended to ensure a quick coupling process and to avoid decoupling impacts. Comparatively, the exponential case was better to reduce infrastructure upgrade requirements and to achieve better comfort. The simulated train movements well matched the designed gap references; Dynamic Coupling was possible in terms of train dynamics in the simulated cases

Tropical methane emissions explain large fraction of recent changes in global atmospheric methane growth rate

Large variations in the growth of atmospheric methane, a prominent greenhouse gas, are driven by a diverse range of anthropogenic and natural emissions and by loss from oxidation by the hydroxyl radical. We used a decade-long dataset (2010–2019) of satellite observations of methane to show that tropical terrestrial emissions explain more than 80% of the observed changes in the global atmospheric methane growth rate over this period. Using correlative meteorological analyses, we show strong seasonal correlations (r = 0.6–0.8) between large-scale changes in sea surface temperature over the tropical oceans and regional variations in methane emissions (via changes in rainfall and temperature) over tropical South America and tropical Africa. Existing predictive skill for sea surface temperature variations could therefore be used to help forecast variations in global atmospheric methane

Southampton Arm Fracture Frailty and Sarcopenia Study (SAFFSS): a study protocol for the feasibility of assessing frailty and sarcopenia among older patients with an upper limb fracture.

INTRODUCTION: Falls are a major health problem for older people; 35% of people aged 65+ years fall every year, leading to fractures in 10%-15%. Upper limb fractures are often the first sign of osteoporosis and routine screening for osteoporosis is recommended by the National Institute for Health and Care Excellence to prevent subsequent hip fractures. However, both frailty and sarcopenia (muscle weakness) are associated with increased risk of falling and fracture but are not routinely identified in this group. The aim of this study is to evaluate the feasibility of assessing and managing frailty and sarcopenia among people aged 65+ years with an upper limb fracture. METHODS AND ANALYSIS: This study will be conducted in three fracture clinics in one acute trust in England. 100 people aged 65+ years with an upper arm fracture will be recruited and assessed using six validated frailty measures and two sarcopenia tools. The prevalence of the two conditions and the best tools to use will be determined. Those with either condition will be referred to geriatric clinical teams for comprehensive geriatric assessment (CGA). We will document the proportion who are referred for CGA and those who receive CGA. Other outcome measures including falls, fractures and healthcare resource use over 6 months will be collected. In-depth interviews with a purposive sample of patients who undergo the frailty and sarcopenia assessments and healthcare professionals in fracture clinics and geriatric services will be carried out to their acceptability of assessing frailty and sarcopenia in a busy environment. ETHICS AND DISSEMINATION: The study was given the relevant ethical approvals from NHS Research Ethics Committee (REC No: 18/NE/0377), the University Hospital Southampton NHS Foundation Trust, and the University of Southampton, Faculty of Medicine Ethics Committee and Research Governance Office. Findings will be published in scientific journals and presented to local, national and international conferences. TRIAL REGISTRATION NUMBER: ISRCTN13848445

Influence of dietary blueberry and broccoli on cecal microbiota activity and colon morphology in mdr1a−/− mice, a model of inflammatory bowel diseases

Objective: Enteric microbiota has been shown to be associated with various pathological conditions such as inflammatory bowel disease (IBD). This study aimed to determine the anti-inflammatory colonic effects of blueberries and broccoli in mdr1a -/- mice (IBD mouse model) through modification of microbiota composition in the gastrointestinal tract. Methods: The mdr1a -/- mice were fed either a control diet or the control diet supplemented with either 10% blueberry or broccoli for 21 wk. We investigated the influence of these diets on cecal microbiota and organic acids, colon morphology, and bacterial translocation to mesenteric lymph nodes. Results: In comparison to mice fed the control diet, blueberry and broccoli supplementation altered cecum microbiota similarly with the exception of Faecalibacterium prausnitzii, which was found to be significantly lower in broccoli-fed mice. High concentrations of butyric acid and low concentrations of succinic acid were observed in the cecum of broccoli-fed mice. Blueberry- and broccoli-supplemented diets increased colon crypt size and the number of goblet cells per crypt. Only the broccoli-supplemented diet significantly lowered colonic inflammation compared to mice fed the control diet. Translocation of total microbes to mesenteric lymph nodes was lower in broccoli-fed mice compared to blueberry and control diet groups. Conclusion: Dietary blueberries and/or broccoli altered the composition and metabolism of the cecal microbiota and colon morphology. Overall, these results warrant further investigation through clinical studies to establish whether the consumption of blueberries and/or broccoli is able to alter the composition and metabolism of large intestine microbiota and promote colon health in humans. © 2012 Elsevier Inc

Patient-reported outcome measures for monitoring primary care patients with depression: PROMDEP feasibility randomised trial

Objectives To determine the feasibility of a trial of patient-reported outcome measures (PROMs) for monitoring primary care patients with depression. Design Partly individually randomised, partly cluster-randomised controlled trial. Setting Nine general practices in Southern England. Participants 47 adults with new episodes of depression: 22 intervention, 25 control. Randomisation Remote computerised sequence generation and allocation. Interventions Patient Health Questionnaire, Distress Thermometer Analogue Scale and PSYCHLOPS problem profile for monitoring depression, following diagnosis and at 10–35 days later. Feedback of scores to patients was determined by practitioners. Blinding Non-blinded, using self-completed measures. Primary outcome Beck Depression Inventory (BDI-II). Secondary outcome measures Work and Social Adjustment Scale (WSAS), EuroQol Five-item, Five-level (EQ-5D-5L) Scale for quality of life, modified Client Service Receipt Inventory for costs, Medical Informant Satisfaction Scale (MISS), qualitative interviews with 14 patients and 13 practice staff about feasibility and acceptability of trial design. Results Three practices failed to recruit the target of six patients in 12 months. Follow-up rates were intervention patients: 18 (82%) at 12 weeks and 15 (68%) at 26 weeks; controls: 18 (72%) and 15 (60%), respectively. At 12 weeks, mean BDI-II score was lower among intervention group patients than controls by 5.8 points (95% CI −11.1 to −0.5), adjusted for baseline differences and clustering. WSAS scores were not significantly different. At 26 weeks, there were no significant differences in symptoms, social functioning, quality of life or costs, but mean satisfaction score was higher among controls by 22.0 points (95% CI −40.7 to −3.29). Intervention patients liked completing PROMs, but were disappointed when practitioners did not use the results to inform management. Conclusions PROMs may improve depression outcome in the short term, even if PROM scores do not inform practitioners' management. Challenges in recruiting and following up patients need addressing for a definitive trial of relatively brief measures which can potentially inform management. https://www.isrctn.com/search?q=97492541 Trial registration number ISRCTN 97492541; Pre-results

Home and Online Management and Evaluation of Blood Pressure (HOME BP) digital intervention for self-management of uncontrolled, essential hypertension: a protocol for the randomised controlled HOME BP trial

Introduction Self-management of hypertension, including self-monitoring and antihypertensive medication titration, lowers blood pressure (BP) at 1 year compared to usual care. The aim of the current trial is to assess the effectiveness of the Home and Online Management and Evaluation of Blood Pressure (HOME BP) intervention for the self-management of hypertension in primary care. Methods and analysis The HOME BP trial will be a randomised controlled trial comparing BP self-management—consisting of the HOME BP online digital intervention with self-monitoring, lifestyle advice and antihypertensive drug titration—with usual care for people with uncontrolled essential hypertension. Eligible patients will be recruited from primary care and randomised to usual care or to self-management using HOME BP. The primary outcome will be the difference in mean systolic BP (mm Hg) at 12-month follow-up between the intervention and control groups adjusting for baseline BP and covariates. Secondary outcomes (also adjusted for baseline and covariates where appropriate) will be differences in mean BP at 6 months and diastolic BP at 12 months; patient enablement; quality of life, and economic analyses including all key resources associated with the intervention and related services, adopting a broad societal perspective to include NHS, social care and patient costs, considered within trial and modelled with a lifetime horizon. Medication beliefs, adherence and changes; self-efficacy; perceived side effects and lifestyle changes will be measured for process analyses. Qualitative analyses will explore patient and healthcare professional experiences of HOME BP to gain insights into the factors affecting acceptability, feasibility and adherence. Ethics and dissemination This study has received NHS ethical approval (REC reference 15/SC/0082). The findings from HOME BP will be disseminated widely through peer-reviewed publications, scientific conferences and workshops. If successful, HOME BP will be directly applicable to UK primary care management of hypertension. Trial registration number ISRCTN13790648; pre-results

An internet-based intervention with brief nurse support to manage obesity in primary care (POWeR+): a pragmatic, parallel-group, randomised controlled trial

Background The obesity epidemic has major public health consequences. Expert dietetic and behavioural counselling with intensive follow-up is effective, but resource requirements severely restrict widespread implementation in primary care, where most patients are managed. We aimed to estimate the effectiveness and cost-effectiveness of an internet-based behavioural intervention (POWeR+) combined with brief practice nurse support in primary care. Methods We did this pragmatic, parallel-group, randomised controlled trial at 56 primary care practices in central and south England. Eligible adults aged 18 years or older with a BMI of 30 kg/m 2 or more (or ≥28 kg/m 2 with hypertension, hypercholesterolaemia, or diabetes) registered online with POWeR+—a 24 session, web-based, weight management intervention lasting 6 months. After registration, the website automatically randomly assigned patients (1:1:1), via computer-generated random numbers, to receive evidence-based dietetic advice to swap foods for similar, but healthier, choices and increase fruit and vegetable intake, in addition to 6 monthly nurse follow-up (control group); web-based intervention and face-to-face nurse support (POWeR+Face-to-face [POWeR+F]; up to seven nurse contacts over 6 months); or web-based intervention and remote nurse support (POWeR+Remote [POWeR+R]; up to five emails or brief phone calls over 6 months). Participants and investigators were masked to group allocation at the point of randomisation; masking of participants was not possible after randomisation. The primary outcome was weight loss averaged over 12 months. We did a secondary analysis of weight to measure maintenance of 5% weight loss at months 6 and 12. We modelled the cost-effectiveness of each intervention. We did analysis by intention to treat, with multiple imputation for missing data. This trial is registered as an International Standard Randomised Controlled Trial, number ISRCTN21244703. Findings Between Jan 30, 2013, and March 20, 2014, 818 participants were randomly assigned to the control group (n=279), the POWeR+F group (n=269), or the POWeR+R group (n=270). Weight loss averaged over 12 months was recorded in 666 (81%) participants. The control group lost almost 3 kg over 12 months (crude mean weight: baseline 104·38 kg [SD 21·11; n=279], 6 months 101·91 kg [19·35; n=136], 12 months 101·74 kg [19·57; n=227]). The primary imputed analysis showed that compared with the control group, patients in the POWeR+F group achieved an additional weight reduction of 1·5 kg (95% CI 0·6–2·4; p=0·001) averaged over 12 months, and patients in the POWeR+R group achieved an additional 1·3 kg (0·34–2·2; p=0·007). 21% of patients in the control group had maintained a clinically important 5% weight reduction at month 12, compared with 29% of patients in the POWeR+F group (risk ratio 1·56, 0·96–2·51; p=0·070) and 32% of patients in the POWeR+R group (1·82, 1·31–2·74; p=0·004). The incremental overall cost to the health service per kg weight lost with the POWeR+ interventions versus the control strategy was £18 (95% CI −129 to 195) for POWeR+F and –£25 (−268 to 157) for POWeR+R; the probability of being cost-effective at a threshold of £100 per kg lost was 88% and 98%, respectively. No adverse events were reported. Interpretation Weight loss can be maintained in some individuals by use of novel written material with occasional brief nurse follow-up. However, more people can maintain clinically important weight reductions with a web-based behavioural program and brief remote follow-up, with no increase in health service costs. Future research should assess the extent to which clinically important weight loss can be maintained beyond 1 year. Funding Health Technology Assessment Programme of the National Institute for Health Research

Delayed antibiotic prescribing for respiratory tract infections: protocol of an individual patient data meta-analysis.

INTRODUCTION: Delayed prescribing can be a useful strategy to reduce antibiotic prescribing, but it is not clear for whom delayed prescribing might be effective. This protocol outlines an individual patient data (IPD) meta-analysis of randomised controlled trials (RCTs) and observational cohort studies to explore the overall effect of delayed prescribing and identify key patient characteristics that are associated with efficacy of delayed prescribing. METHODS AND ANALYSIS: A systematic search of the databases Cochrane Central Register of Controlled Trials, Ovid MEDLINE, Ovid Embase, EBSCO CINAHL Plus and Web of Science was conducted to identify relevant studies from inception to October 2017. Outcomes of interest include duration of illness, severity of illness, complication, reconsultation and patient satisfaction. Study authors of eligible papers will be contacted and invited to contribute raw IPD data. IPD data will be checked against published data, harmonised and aggregated to create one large IPD database. Multilevel regression will be performed to explore interaction effects between treatment allocation and patient characteristics. The economic evaluation will be conducted based on IPD from the combined trial and observational studies to estimate the differences in costs and effectiveness for delayed prescribing compared with normal practice. A decision model will be developed to assess potential savings and cost-effectiveness in terms of reduced antibiotic usage of delayed prescribing and quality-adjusted life years. ETHICS AND DISSEMINATION: Ethical approval was obtained from the University of Southampton Faculty of Medicine Research Ethics Committee (Reference number: 30068). Findings of this study will be published in peer-reviewed academic journals as well as General Practice trade journals and will be presented at national and international conferences. The results will have important public health implications, shaping the way in which antibiotics are prescribed in the future and to whom delayed prescriptions are issued. PROSPERO REGISTRATION NUMBER: CRD42018079400