104 research outputs found

    Extending a Task Allocation Algorithm for Graceful Degradation of Real-Time Distributed Embedded Systems

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    Previous research which has considered task allocation and fault-tolerance together has concentrated on construct-ing schedules which accommodate a fixed number of redun-dant tasks. Often, all faults are treated as being equally severe. There is little work which combines task allocation with architectural level fault-tolerance issues such as the number of replicas to use and how they should be config-ured, both of which are tackled by this work. An accepted method for assessing the impact of a combination of faults is to build a system utility model which can be used to assess how the system degrades when components fail. The key challenge addressed here is how to design objective func-tions based on a utility model which can be incorporated into a search algorithm in order to optimise fault-tolerance properties. Other issues such as how to extend the local search neighbourhood and balance objectives with schedu-lability constraints are also discussed.

    Adaptive partitioning of real-time tasks on multiple processors

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    This paper presents a new algorithm for scheduling real-time tasks on multiprocessor/multicore systems. This new algorithm is based on combining EDF scheduling with a migration strategy that moves tasks only when needed. It has been evaluated through an extensive set of simulations that showed good performance when compared with global or partitioned EDF: a worst-case utilisation bound similar to partitioned EDF for hard real-time tasks, and a tardiness bound similar to global EDF for soft real-time tasks. Therefore, the proposed scheduler is effective for dealing with both soft and hard real-time workloads

    Campath, calcineurin inhibitor reduction and chronic allograft nephropathy (3C) study: background, rationale, and study protocol.

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    BACKGROUND: Kidney transplantation is the best treatment for patients with end-stage renal failure, but uncertainty remains about the best immunosuppression strategy. Long-term graft survival has not improved substantially, and one possible explanation is calcineurin inhibitor (CNI) nephrotoxicity. CNI exposure could be minimized by using more potent induction therapy or alternative maintenance therapy to remove CNIs completely. However, the safety and efficacy of such strategies are unknown. METHODS/DESIGN: The Campath, Calcineurin inhibitor reduction and Chronic allograft nephropathy (3C) Study is a multicentre, open-label, randomized controlled trial with 852 participants which is addressing two important questions in kidney transplantation. The first question is whether a Campath (alemtuzumab)-based induction therapy strategy is superior to basiliximab-based therapy, and the second is whether, from 6 months after transplantation, a sirolimus-based maintenance therapy strategy is superior to tacrolimus-based therapy. Recruitment is complete, and follow-up will continue for around 5 years post-transplant. The primary endpoint for the induction therapy comparison is biopsy-proven acute rejection by 6 months, and the primary endpoint for the maintenance therapy comparison is change in estimated glomerular filtration rate from baseline to 2 years after transplantation. The study is sponsored by the University of Oxford and endorsed by the British Transplantation Society, and 18 centers for adult kidney transplant are participating. DISCUSSION: Late graft failure is a major issue for kidney-transplant recipients. If our hypothesis that minimizing CNI exposure with Campath-based induction therapy and/or an elective conversion to sirolimus-based maintenance therapy can improve long-term graft function and survival is correct, then patients should experience better graft function for longer. A positive outcome could change clinical practice in kidney transplantation. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01120028 and ISRCTN88894088.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

    Circulating soluble receptor for advanced glycation end product: Cross-sectional associations with cardiac markers and subclinical vascular disease in older men with and without diabetes.

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    BACKGROUND AND AIMS: The soluble receptor for advanced glycation end products (sRAGE) has been implicated in diabetic vascular complications. We have examined the association between sRAGE and cardiac markers [NT-proBNP and cardiac troponin T (cTnT)] and subclinical vascular markers in older men with and without diabetes. METHODS: We performed a cross-sectional study of 1159 men aged 71-92 years with no history of cardiovascular disease (myocardial infarction, stroke, heart failure, coronary artery bypass graft operation or angioplasty). Prevalent diabetes included men with a doctor diagnosis of diabetes, men with fasting glucose ≥7 mmol/l or HbA1c ≥ 6.5% (N = 180). Subclinical vascular measurements included carotid intima media thickness (cIMT), arterial stiffness [pulse wave velocity (PWV)], central aortic blood pressure and arterial wave reflections [central augmentation pressure (AP) and augmentation index (AIx)]. RESULTS: sRAGE was strongly and positively associated with renal dysfunction in men with and without diabetes. sRAGE was significantly and positively associated with NT-proBNP (but not cTnT) and AP and AIx in both groups of men after adjustment for CVD risk and metabolic risk markers, renal function and inflammation. However, no association was seen between sRAGE and central aortic blood pressure, cIMT or arterial stiffness as determined by PWV in either group. CONCLUSIONS: Higher plasma sRAGE was associated with increased NT-proBNP and markers of arterial wave reflections in men both with and without diabetes. Increased sRAGE may contribute to or be a marker of worsening cardiac dysfunction or HF. Further studies with cardiac imaging data are required to confirm this

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Increasing value and reducing waste in stroke research

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    Stroke represents a major burden to patients and society, and resources spent on stroke research must be used efficiently and produce good value in terms of improvements in human health. However, there are many examples of poor value from stroke research funding, which result from the way in which stroke research has been chosen, designed, conducted, analysed, regulated, managed, disseminated, or reported. In a project including a survey and a symposium and involving stroke researchers in the European Stroke Organisation we have sought to identify sources of inefficiency and waste, recommended approaches to increase value, and highlighted examples of best practice in stroke research. Recent evidence suggests that progress has been made, but there is room for much improvement, and stroke researchers, funders and other stakeholders might consider our recommendations when planning new research

    Efficacy and safety of statin therapy in older people: a meta-analysis of individual participant data from 28 randomised controlled trials

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    Background: Statin therapy has been shown to reduce major vascular events and vascular mortality in a wide range of individuals, but there is uncertainty about its efficacy and safety among older people. We undertook a meta-analysis of data from all large statin trials to compare the effects of statin therapy at different ages. Methods: In this meta-analysis, randomised trials of statin therapy were eligible if they aimed to recruit at least 1000 participants with a scheduled treatment duration of at least 2 years. We analysed individual participant data from 22 trials (n=134 537) and detailed summary data from one trial (n=12 705) of statin therapy versus control, plus individual participant data from five trials of more intensive versus less intensive statin therapy (n=39 612). We subdivided participants into six age groups (55 years or younger, 56–60 years, 61–65 years, 66–70 years, 71–75 years, and older than 75 years). We estimated effects on major vascular events (ie, major coronary events, strokes, and coronary revascularisations), cause-specific mortality, and cancer incidence as the rate ratio (RR) per 1·0 mmol/L reduction in LDL cholesterol. We compared proportional risk reductions in different age subgroups by use of standard χ2 tests for heterogeneity when there were two groups, or trend when there were more than two groups. Findings: 14 483 (8%) of 186 854 participants in the 28 trials were older than 75 years at randomisation, and the median follow-up duration was 4·9 years. Overall, statin therapy or a more intensive statin regimen produced a 21% (RR 0·79, 95% CI 0·77–0·81) proportional reduction in major vascular events per 1·0 mmol/L reduction in LDL cholesterol. We observed a significant reduction in major vascular events in all age groups. Although proportional reductions in major vascular events diminished slightly with age, this trend was not statistically significant (ptrend=0·06). Overall, statin or more intensive therapy yielded a 24% (RR 0·76, 95% CI 0·73–0·79) proportional reduction in major coronary events per 1·0 mmol/L reduction in LDL cholesterol, and with increasing age, we observed a trend towards smaller proportional risk reductions in major coronary events (ptrend=0·009). We observed a 25% (RR 0·75, 95% CI 0·73–0·78) proportional reduction in the risk of coronary revascularisation procedures with statin therapy or a more intensive statin regimen per 1·0 mmol/L lower LDL cholesterol, which did not differ significantly across age groups (ptrend=0·6). Similarly, the proportional reductions in stroke of any type (RR 0·84, 95% CI 0·80–0·89) did not differ significantly across age groups (ptrend=0·7). After exclusion of four trials which enrolled only patients with heart failure or undergoing renal dialysis (among whom statin therapy has not been shown to be effective), the trend to smaller proportional risk reductions with increasing age persisted for major coronary events (ptrend=0·01), and remained non-significant for major vascular events (ptrend=0·3). The proportional reduction in major vascular events was similar, irrespective of age, among patients with pre-existing vascular disease (ptrend=0·2), but appeared smaller among older than among younger individuals not known to have vascular disease (ptrend=0·05). We found a 12% (RR 0·88, 95% CI 0·85–0·91) proportional reduction in vascular mortality per 1·0 mmol/L reduction in LDL cholesterol, with a trend towards smaller proportional reductions with older age (ptrend=0·004), but this trend did not persist after exclusion of the heart failure or dialysis trials (ptrend=0·2). Statin therapy had no effect at any age on non-vascular mortality, cancer death, or cancer incidence. Interpretation: Statin therapy produces significant reductions in major vascular events irrespective of age, but there is less direct evidence of benefit among patients older than 75 years who do not already have evidence of occlusive vascular disease. This limitation is now being addressed by further trials. Funding: Australian National Health and Medical Research Council, National Institute for Health Research Oxford Biomedical Research Centre, UK Medical Research Council, and British Heart Foundation

    Interpretation of the evidence for the efficacy and safety of statin therapy

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    This Review is intended to help clinicians, patients, and the public make informed decisions about statin therapy for the prevention of heart attacks and strokes. It explains how the evidence that is available from randomised controlled trials yields reliable information about both the effi cacy and safety of statin therapy. In addition, it discusses how claims that statins commonly cause adverse eff ects refl ect a failure to recognise the limitations of other sources of evidence about the eff ects of treatment. Large-scale evidence from randomised trials shows that statin therapy reduces the risk of major vascular events (ie, coronary deaths or myocardial infarctions, strokes, and coronary revascularisation procedures) by about one-quarter for each mmol/L reduction in LDL cholesterol during each year (after the fi rst) that it continues to be taken. The absolute benefi ts of statin therapy depend on an individual’s absolute risk of occlusive vascular events and the absolute reduction in LDL cholesterol that is achieved. For example, lowering LDL cholesterol by 2 mmol/L (77 mg/dL) with an eff ective low-cost statin regimen (eg, atorvastatin 40 mg daily, costing about £2 per month) for 5 years in 10 000 patients would typically prevent major vascular events from occurring in about 1000 patients (ie, 10% absolute benefi t) with pre-existing occlusive vascular disease (secondary prevention) and in 500 patients (ie, 5% absolute benefi t) who are at increased risk but have not yet had a vascular event (primary prevention). Statin therapy has been shown to reduce vascular disease risk during each year it continues to be taken, so larger absolute benefi ts would accrue with more prolonged therapy, and these benefi ts persist long term. The only serious adverse events that have been shown to be caused by long-term statin therapy—ie, adverse eff ects of the statin—are myopathy (defi ned as muscle pain or weakness combined with large increases in blood concentrations of creatine kinase), new-onset diabetes mellitus, and, probably, haemorrhagic stroke. Typically, treatment of 10 000 patients for 5 years with an eff ective regimen (eg, atorvastatin 40 mg daily) would cause about 5 cases of myopathy (one of which might progress, if the statin therapy is not stopped, to the more severe condition of rhabdomyolysis), 50–100 new cases of diabetes, and 5–10 haemorrhagic strokes. However, any adverse impact of these side-eff ects on major vascular events has already been taken into account in the estimates of the absolute benefi ts. Statin therapy may cause symptomatic adverse events (eg, muscle pain or weakness) in up to about 50–100 patients (ie, 0·5–1·0% absolute harm) per 10 000 treated for 5 years. However, placebo-controlled randomised trials have shown defi nitively that almost all of the symptomatic adverse events that are attributed to statin therapy in routine practice are not actually caused by it (ie, they represent misattribution). The large-scale evidence available from randomised trials also indicates that it is unlikely that large absolute excesses in other serious adverse events still await discovery. Consequently, any further fi ndings that emerge about the eff ects of statin therapy would not be expected to alter materially the balance of benefi ts and harms. It is, therefore, of concern that exaggerated claims about side-eff ect rates with statin therapy may be responsible for its under-use among individuals at increased risk of cardiovascular events. For, whereas the rare cases of myopathy and any muscle-related symptoms that are attributed to statin therapy generally resolve rapidly when treatment is stopped, the heart attacks or strokes that may occur if statin therapy is stopped unnecessarily can be devastating

    Casirivimab and imdevimab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

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    Background Casirivimab and imdevimab are non-competing monoclonal antibodies that bind to two different sites on the receptor binding domain of the SARS-CoV-2 spike glycoprotein, blocking viral entry into host cells. We aimed to evaluate the efficacy and safety of casirivimab and imdevimab administered in combination in patients admitted to hospital with COVID-19. Methods RECOVERY is a randomised, controlled, open-label platform trial comparing several possible treatments with usual care in patients admitted to hospital with COVID-19. 127 UK hospitals took part in the evaluation of casirivimab and imdevimab. Eligible participants were any patients aged at least 12 years admitted to hospital with clinically suspected or laboratory-confirmed SARS-CoV-2 infection. Participants were randomly assigned (1:1) to either usual standard of care alone or usual care plus casirivimab 4 g and imdevimab 4 g administered together in a single intravenous infusion. Investigators and data assessors were masked to analyses of the outcome data during the trial. The primary outcome was 28-day all-cause mortality assessed by intention to treat, first only in patients without detectable antibodies to SARS-CoV-2 infection at randomisation (ie, those who were seronegative) and then in the overall population. Safety was assessed in all participants who received casirivimab and imdevimab. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). Findings Between Sept 18, 2020, and May 22, 2021, 9785 patients enrolled in RECOVERY were eligible for casirivimab and imdevimab, of which 4839 were randomly assigned to casirivimab and imdevimab plus usual care and 4946 to usual care alone. 3153 (32%) of 9785 patients were seronegative, 5272 (54%) were seropositive, and 1360 (14%) had unknown baseline antibody status. 812 (8%) patients were known to have received at least one dose of a SARS-CoV-2 vaccine. In the primary efficacy population of seronegative patients, 396 (24%) of 1633 patients allocated to casirivimab and imdevimab versus 452 (30%) of 1520 patients allocated to usual care died within 28 days (rate ratio [RR] 0·79, 95% CI 0·69–0·91; p=0·0009). In an analysis of all randomly assigned patients (regardless of baseline antibody status), 943 (19%) of 4839 patients allocated to casirivimab and imdevimab versus 1029 (21%) of 4946 patients allocated to usual care died within 28 days (RR 0·94, 95% CI 0·86–1·02; p=0·14). The proportional effect of casirivimab and imdevimab on mortality differed significantly between seropositive and seronegative patients (p value for heterogeneity=0·002). There were no deaths attributed to the treatment, or meaningful between-group differences in the pre-specified safety outcomes of cause-specific mortality, cardiac arrhythmia, thrombosis, or major bleeding events. Serious adverse reactions reported in seven (<1%) participants were believed by the local investigator to be related to treatment with casirivimab and imdevimab. Interpretation In patients admitted to hospital with COVID-19, the monoclonal antibody combination of casirivimab and imdevimab reduced 28-day mortality in patients who were seronegative (and therefore had not mounted their own humoral immune response) at baseline but not in those who were seropositive at baseline

    Protein-truncating variants in BSN are associated with severe adult-onset obesity, type 2 diabetes and fatty liver disease.

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    This is the final version. Available from Nature Research via the DOI in this record. Data availability: The UK Biobank phenotype and WES data described here are publicly available to registered researchers through the UK Biobank data access protocol. Information about registration for access to the data is available at https://www.ukbiobank.ac.uk/enable-your-research/apply-for-access. Data for this study were obtained under resource applications 26041 and 9905. The MCPS welcomes open-access and collaboration data requests from bona fide researchers. For more details on accessibility, the study’s data and sample sharing policy can be downloaded (in English or Spanish) from https://www.ctsu.ox.ac.uk/research/mcps. Available study data can be examined in detail through the study’s Data Showcase, available at https://datashare.ndph.ox.ac.uk/mexico/. SCOOP and INTERVAL WES data are accessible from the European Genome-phenome Archive with accession numbers EGAS00001000124 (SCOOP) and EGAS00001000825 (INTERVAL). snRNA-seq data are available from the NCBI Gene Expression Omnibus (GEO), under accession number: GSE243112. Source data are provided with this paper.Code availability: The pipeline code for processing, filtering, annotating and burden testing UK Biobank WES data using the UK Biobank RAP is publicly available (https://github.com/mrcepid-rap). No custom code for analyzing the UK Biobank WES data was developed for this study. The analysis code for single-nucleus sequencing is available on GitHub (https://github.com/mariachukanova1/BSN_paper) and has been deposited on Zenodo at https://doi.org/10.5281/zenodo.10687754.Obesity is a major risk factor for many common diseases and has a substantial heritable component. To identify new genetic determinants, we performed exome-sequence analyses for adult body mass index (BMI) in up to 587,027 individuals. We identified rare loss-of-function variants in two genes (BSN and APBA1) with effects substantially larger than those of well-established obesity genes such as MC4R. In contrast to most other obesity-related genes, rare variants in BSN and APBA1 were not associated with normal variation in childhood adiposity. Furthermore, BSN protein-truncating variants (PTVs) magnified the influence of common genetic variants associated with BMI, with a common variant polygenic score exhibiting an effect twice as large in BSN PTV carriers than in noncarriers. Finally, we explored the plasma proteomic signatures of BSN PTV carriers as well as the functional consequences of BSN deletion in human induced pluripotent stem cell-derived hypothalamic neurons. Collectively, our findings implicate degenerative processes in synaptic function in the etiology of adult-onset obesity.Medical Research CouncilMedical Research CouncilMedical Research CouncilMedical Research CouncilWellcome TrustMedical Research CouncilWellcome TrustWellcome Trust and Royal SocietyChan Zuckerberg InitiativeBiotechnology and Biological Sciences Research Council (BBSRC)Mexican Health MinistryNational Council of Science and Technology for MexicoCancer Research UKBritish Heart FoundationNational Institute for Health ResearchCambridge Biomedical Research CentreBotnar FoundationBernard Wolfe Health Neuroscience EndowmentResearch Englan
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