97 research outputs found

    Tactically Extensible and Modular Communications - X-Band TEMCOM-X

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    This paper will discuss a proposed CubeSat size (3U) telemetry system concept being developed at Marshall Space Flight Center (MSFC) in cooperation with the U.S. Department of the Army and Dynetics Corporation. This telemetry system incorporates efficient, high-bandwidth communications by developing flight-ready, low-cost, Protoflight software defined radio (SDR) and Electronically Steerable Patch Array (ESPA) antenna subsystems for use on platforms as small as CubeSats and unmanned aircraft systems (UASs). The current telemetry system is slightly larger in dimension of footprint than required to fit within a 0.5U CubeSat volume. Extensible and modular communications for CubeSat technologies will partially mitigate current capability gaps between traditional strategic space platforms and lower-cost small satellite solutions. Higher bandwidth capacity will enable high-volume, low error-rate data transfer to and from tactical forces or sensors operating in austere locations (e.g., direct imagery download, unattended ground sensor data exfiltration, interlink communications), while also providing additional bandwidth and error correction margin to accommodate more complex encryption algorithms and higher user volume

    Anti-Inflammatory Cytokines Predominate in Acute Human Plasmodium knowlesi Infections

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    Plasmodium knowlesi has entered the human population of Southeast Asia. Naturally acquired knowlesi malaria is newly described with relatively little available data, including data on the host response to infection. Therefore pre-treatment cytokine and chemokine profiles were determined for 94 P. knowlesi, and for comparison, 20, P. vivax and 22 P. falciparum, patients recruited in Malaysian Borneo. Nine, five and one patient with P. knowlesi, P. falciparum and P. vivax respectively had complicated malaria as defined by World Health Organisation. Patients with uncomplicated P. knowlesi had lower levels of the pro-inflammatory cytokines IL-8 and TNFα than those with complicated disease (both p<0.05, Dunn's post test, DPT). The anti-inflammatory cytokines IL-1ra and IL-10 were detected in all patients in the study. IL-1ra, the most abundant cytokine measured, correlated with parasitaemia in P. knowlesi (rs = 0.47, p =  <0.0001), P. vivax (rs = 0.61, p = 0.0042) and P. falciparum (rs = 0.57,p = 0.0054) malaria. IL-10 correlated with parasitaemia in both P. knowlesi (rs = 0.54, p =  <0.0001) and P. vivax (rs = 0.78, p =  <0.0001) infections. There were between group differences in soluble markers of macrophage activation (MIP-1β and MCP-1). P. knowlesi patients had significantly lower levels of MIP-1β than P. falciparum (DPT, p =  <0.01). Uncomplicated P. knowlesi patients had significantly lower levels of MCP-1 than uncomplicated P. falciparum patients (DPT, p =  <0.001). There was no significant difference between complicated and uncomplicated P. knowlesi infections. MCP-1, MIP-1β, IL-8 and TNFα increased in complicated P. knowlesi but decreased in complicated P. falciparum infections. Descriptions of human knowlesi malaria provide a comparative means to discover mediators of pathophysiology in severe P. knowlesi as well as P. falciparum malaria. Crucially, P. knowlesi may be the disease and experimental primate model for severe malaria

    The methodology for developing a prospective meta-analysis in the family planning community

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    <p>Abstract</p> <p>Background</p> <p>Prospective meta-analysis (PMA) is a collaborative research design in which individual sites perform randomized controlled trials (RCTs) and pool the data for meta-analysis. Members of the PMA collaboration agree upon specific research interventions and outcome measures, ideally before initiation but at least prior to any individual trial publishing results. This allows for uniform reporting of primary and secondary outcomes. With this approach, heterogeneity among trials contributing data for the final meta-analysis is minimized while each site maintains the freedom to design a specific trial. This paper describes the process of creating a PMA collaboration to evaluate the impact of misoprostol on ease of intrauterine device (IUD) insertion in nulliparous women.</p> <p>Methods</p> <p>After the principal investigator developed a preliminary PMA protocol, he identified potential collaborating investigators at other sites. One site already had a trial underway and another site was in the planning stages of a trial meeting PMA requirements. Investigators at six sites joined the PMA collaborative. Each site committed to enroll subjects to meet a pre-determined total sample size. A final common research plan and site responsibilities were developed and agreed upon through email and face-to-face meetings. Each site committed to contribute individual patient data to the PMA collaboration, and these data will be analyzed and prepared as a multi-site publication. Individual sites retain the ability to analyze and publish their site's independent findings.</p> <p>Results</p> <p>All six sites have obtained Institutional Review Board approval and each has obtained individual funding to meet the needs of that site's study. Sites have shared resources including study protocols and consents to decrease costs and improve study flow. This PMA protocol is registered with the Cochrane Collaboration and data will be analyzed according to Cochrane standards for meta-analysis.</p> <p>Conclusions</p> <p>PMA is a novel research method that improves meta-analysis by including several study sites, establishing uniform reporting of specific outcomes, and yet allowing some independence on the part of individual sites with respect to the conduct of research. The inclusion of several sites increases statistical power to address important clinical questions. Compared to multi-center trials, PMA methodology encourages collaboration, aids in the development of new investigators, decreases study costs, and decreases time to publication.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00613366">NCT00613366</a>, <a href="http://www.clinicaltrials.gov/ct2/show/NCT00886834">NCT00886834</a>, <a href="http://www.clinicaltrials.gov/ct2/show/NCT01001897">NCT01001897</a>, <a href="http://www.clinicaltrials.gov/ct2/show/NCT01147497">NCT01147497</a> and <a href="http://www.clinicaltrials.gov/ct2/show/NCT01307111">NCT01307111</a></p

    Guidance on noncorticosteroid systemic immunomodulatory therapy in noninfectious uveitis: fundamentals of care for uveitis (focus) initiative

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    Topic: An international, expert-led consensus initiative to develop systematic, evidence-based recommendations for the treatment of noninfectious uveitis in the era of biologics. Clinical Relevance: The availability of biologic agents for the treatment of human eye disease has altered practice patterns for the management of noninfectious uveitis. Current guidelines are insufficient to assure optimal use of noncorticosteroid systemic immunomodulatory agents. Methods: An international expert steering committee comprising 9 uveitis specialists (including both ophthalmologists and rheumatologists) identified clinical questions and, together with 6 bibliographic fellows trained in uveitis, conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol systematic reviewof the literature (English language studies from January 1996 through June 2016; Medline [OVID], the Central Cochrane library, EMBASE,CINAHL,SCOPUS,BIOSIS, andWeb of Science). Publications included randomized controlled trials, prospective and retrospective studies with sufficient follow-up, case series with 15 cases or more, peer-reviewed articles, and hand-searched conference abstracts from key conferences. The proposed statements were circulated among 130 international uveitis experts for review.Atotal of 44 globally representativegroupmembersmet in late 2016 to refine these guidelines using a modified Delphi technique and assigned Oxford levels of evidence. Results: In total, 10 questions were addressed resulting in 21 evidence-based guidance statements covering the following topics: when to start noncorticosteroid immunomodulatory therapy, including both biologic and nonbiologic agents; what data to collect before treatment; when to modify or withdraw treatment; how to select agents based on individual efficacy and safety profiles; and evidence in specific uveitic conditions. Shared decision-making, communication among providers and safety monitoring also were addressed as part of the recommendations. Pharmacoeconomic considerations were not addressed. Conclusions: Consensus guidelines were developed based on published literature, expert opinion, and practical experience to bridge the gap between clinical needs and medical evidence to support the treatment of patients with noninfectious uveitis with noncorticosteroid immunomodulatory agents

    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

    Multifactorial falls prevention programme compared with usual care in UK care homes for older people: Multicentre cluster randomised controlled trial with economic evaluation

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    Objectives: To determine the clinical and cost effectiveness of a multifactorial fall prevention programme compared with usual care in long term care homes. Design: Multicentre, parallel, cluster randomised controlled trial. Setting: Long term care homes in the UK, registered to care for older people or those with dementia. Participants: 1657 consenting residents and 84 care homes. 39 were randomised to the intervention group and 45 were randomised to usual care. Interventions: Guide to Action for Care Homes (GtACH): a multifactorial fall prevention programme or usual care. Main outcome measures: Primary outcome measure was fall rate at 91-180 days after randomisation. The economic evaluation measured health related quality of life using quality adjusted life years (QALYs) derived from the five domain five level version of the EuroQoL index (EQ-5D-5L) or proxy version (EQ-5D-5L-P) and the Dementia Quality of Life utility measure (DEMQOL-U), which were self-completed by competent residents and by a care home staff member proxy (DEMQOL-P-U) for all residents (in case the ability to complete changed during the study) until 12 months after randomisation. Secondary outcome measures were falls at 1-90, 181-270, and 271-360 days after randomisation, Barthel index score, and the Physical Activity Measure-Residential Care Homes (PAM-RC) score at 91, 180, 270, and 360 days after randomisation. Results: Mean age of residents was 85 years. 32% were men. GtACH training was delivered to 1051/1480 staff (71%). Primary outcome data were available for 630 participants in the GtACH group and 712 in the usual care group. The unadjusted incidence rate ratio for falls between 91 and 180 days was 0.57 (95% confidence interval 0.45 to 0.71, P<0.001) in favour of the GtACH programme (GtACH: six falls/1000 residents v usual care: 10 falls/1000). Barthel activities of daily living indices and PAM-RC scores were similar between groups at all time points. The incremental cost was £108 (95% confidence interval −£271.06 to 487.58), incremental QALYs gained for EQ-5D-5L-P was 0.024 (95% confidence interval 0.004 to 0.044) and for DEMQOL-P-U was 0.005 (−0.019 to 0.03). The incremental costs per EQ-5D-5L-P and DEMQOL-P-U based QALY were £4544 and £20 889, respectively. Conclusions: The GtACH programme was associated with a reduction in fall rate and cost effectiveness, without a decrease in activity or increase in dependency. Trial registration: ISRCTN34353836

    A multidomain decision support tool to prevent falls in older people: the FinCH cluster RCT

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    BackgroundFalls in care home residents are common, unpleasant, costly and difficult to prevent.ObjectivesThe objectives were to evaluate the clinical effectiveness and cost-effectiveness of the Guide to Action for falls prevention in Care Homes (GtACH) programme.DesignA multicentre, cluster, parallel, 1 : 1 randomised controlled trial with embedded process evaluation and economic evaluation. Care homes were randomised on a 1 : 1 basis to the GtACH programme or usual care using a secure web-based randomisation service. Research assistants, participating residents and staff informants were blind to allocation at recruitment; research assistants were blind to allocation at follow-up. NHS Digital data were extracted blindly.SettingOlder people’s care homes from 10 UK sites.ParticipantsOlder care home residents.InterventionThe GtACH programme, which includes care home staff training, systematic use of a multidomain decision support tool and implementation of falls prevention actions, compared to usual falls prevention care.OutcomesThe primary trial outcome was the rate of falls per participating resident occurring during the 90-day period between 91 and 180 days post randomisation. The primary outcome for the cost-effectiveness analysis was the cost per fall averted, and the primary outcome for the cost–utility analysis was the incremental cost per quality adjusted life-year. Secondary outcomes included the rate of falls over days 0–90 and 181–360 post randomisation, activity levels, dependency and fractures. The number of falls per resident was compared between arms using a negative binomial regression model (generalised estimating equation).ResultsA total of 84 care homes were randomised: 39 to the GtACH arm and 45 to the control arm. A total of 1657 residents consented and provided baseline measures (mean age 85 years, 32% men). GtACH programme training was delivered to 1051 staff (71% of eligible staff) over 146 group sessions. Primary outcome data were available for 630 GtACH participants and 712 control participants. The primary outcome result showed an unadjusted incidence rate ratio of 0.57 (95% CI 0.45 to 0.71; p < 0.01) in favour of the GtACH programme. Falls rates were lower in the GtACH arm in the period 0–90 days. There were no other differences between arms in the secondary outcomes. Care home staff valued the training, systematic strategies and specialist peer support, but the incorporation of the GtACH programme documentation into routine care home practice was limited. No adverse events were recorded. The incremental cost was £20,889.42 per Dementia Specific Quality of Life-based quality-adjusted life-year and £4543.69 per quality-adjusted life-year based on the EuroQol-5 dimensions, five-level version. The mean number of falls was 1.889 (standard deviation 3.662) in the GtACH arm and 2.747 (standard deviation 7.414) in the control arm. Therefore, 0.858 falls were averted. The base-case incremental cost per fall averted was £190.62.ConclusionThe GtACH programme significantly reduced the falls rate in the study care homes without restricting residents’ activity levels or increasing their dependency, and was cost-effective at current thresholds in the NHS.Future workFuture work should include a broad implementation programme, focusing on scale and sustainability of the GtACH programme.LimitationsA key limitation was the fact that care home staff were not blinded, although risk was small because of the UK statutory requirement to record falls in care homes.Trial registrationThis trial is registered as ISRCTN34353836.FundingThis 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. 26, No. 9. See the NIHR Journals Library website for further project information

    Convergent genetic and expression data implicate immunity in Alzheimer's disease

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    Background Late–onset Alzheimer's disease (AD) is heritable with 20 genes showing genome wide association in the International Genomics of Alzheimer's Project (IGAP). To identify the biology underlying the disease we extended these genetic data in a pathway analysis. Methods The ALIGATOR and GSEA algorithms were used in the IGAP data to identify associated functional pathways and correlated gene expression networks in human brain. Results ALIGATOR identified an excess of curated biological pathways showing enrichment of association. Enriched areas of biology included the immune response (p = 3.27×10-12 after multiple testing correction for pathways), regulation of endocytosis (p = 1.31×10-11), cholesterol transport (p = 2.96 × 10-9) and proteasome-ubiquitin activity (p = 1.34×10-6). Correlated gene expression analysis identified four significant network modules, all related to the immune response (corrected p 0.002 – 0.05). Conclusions The immune response, regulation of endocytosis, cholesterol transport and protein ubiquitination represent prime targets for AD therapeutics

    Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease

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    We identified rare coding variants associated with Alzheimer’s disease (AD) in a 3-stage case-control study of 85,133 subjects. In stage 1, 34,174 samples were genotyped using a whole-exome microarray. In stage 2, we tested associated variants (P<1×10-4) in 35,962 independent samples using de novo genotyping and imputed genotypes. In stage 3, an additional 14,997 samples were used to test the most significant stage 2 associations (P<5×10-8) using imputed genotypes. We observed 3 novel genome-wide significant (GWS) AD associated non-synonymous variants; a protective variant in PLCG2 (rs72824905/p.P522R, P=5.38×10-10, OR=0.68, MAFcases=0.0059, MAFcontrols=0.0093), a risk variant in ABI3 (rs616338/p.S209F, P=4.56×10-10, OR=1.43, MAFcases=0.011, MAFcontrols=0.008), and a novel GWS variant in TREM2 (rs143332484/p.R62H, P=1.55×10-14, OR=1.67, MAFcases=0.0143, MAFcontrols=0.0089), a known AD susceptibility gene. These protein-coding changes are in genes highly expressed in microglia and highlight an immune-related protein-protein interaction network enriched for previously identified AD risk genes. These genetic findings provide additional evidence that the microglia-mediated innate immune response contributes directly to AD development
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