460 research outputs found

    NASA Leveraging Commercial Communication Ground Stations for Small Satellites

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    The Space Communications and Navigation (SCaN) program at NASA has reorganized its operations portfolio into two networks: the Deep Space Network and the new Near Space Network (NSN). With this reorganization, NASA can begin transforming to 100% direct-to-Earth commercial communications services for missions in the near-Earth region. NASA’s leveraging of commercial direct-to-Earth ground stations offers several benefits for the small satellite community, including lower cost, greater coverage, and increased technology infusion. In the fall of 2020, SCaN announced their intention to rely primarily on industry-provided communications services for missions close to Earth by 2030. Commercial services are one way to infuse new technology into the ground station network without requiring an investment from NASA. Digital Video Broadcast, Satellite Second Generation (DVB-S2) is one example of a current technology. When combined with variable coding and modulation (VCM), the system automatically optimizes the data rate based on signal performance, significantly increasing total downlink data volume without an increase in the spacecraft effective isotropic radiated power (EIRP). There are several commercial service providers, including Amazon Web Service (AWS) Ground Station (AGS) and the KSATLITE ground stations that support SmallSat missions using DVB-S2 waveforms for downlinks. This paper identifies some commercial off-the-shelf (COTS) CubeSat/SmallSat DVB-S2 X-band and Ka-band radios. Overall, NASA’s increased dependence on commercial direct-to-Earth ground stations is a significant benefit for the small satellite community

    The influence of insurance status on access to and utilization of a tertiary hand surgery referral center

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    BACKGROUND: The purpose of this study was to systematically examine the impact of insurance status on access to and utilization of elective specialty hand surgical care. We hypothesized that patients with Medicaid insurance or those without insurance would have greater difficulty accessing care both in obtaining local surgical care and in reaching a tertiary center for appointments. METHODS: This retrospective cohort study included all new patients with orthopaedic hand problems (n = 3988) at a tertiary center in a twelve-month period. Patient insurance status was categorized and clinical complexity was quantified on an ordinal scale. The relationships of insurance status, clinical complexity, and distance traveled to appointments were quantified by means of statistical analysis. An assessment of barriers to accessing care stratified with regard to insurance status was completed through a survey of primary care physicians and an analysis of both patient arrival rates and operative rates at our tertiary center. RESULTS: Increasing clinical complexity significantly correlated (p < 0.001) with increasing driving distance to the appointment. Patients with Medicaid insurance were significantly less likely (p < 0.001) to present with problems of simple clinical complexity than patients with Medicare and those with private insurance. Primary care physicians reported that 62% of local surgeons accepted patients with Medicaid insurance and 100% of local surgeons accepted patients with private insurance. Forty-four percent of these primary care physicians reported that, if patients who were underinsured (i.e., patients with Medicaid insurance or no insurance) had been refused by community surgeons, they were unable to drive to our tertiary center because of limited personal resources. Patients with Medicaid insurance (26%) were significantly more likely (p < 0.001) to fail to arrive for appointments than patients with private insurance (11%), with no-show rates increasing with the greater distance required to reach the tertiary center. CONCLUSIONS: Economically disadvantaged patients face barriers to accessing specialty surgical care. Among patients with Medicaid coverage or no insurance, local surgical care is less likely to be offered and yet personal resources may limit a patient’s ability to reach distant centers for non-emergency care. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence

    Human Factors and Simulation in Emergency Medicine

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    This consensus group from the 2017 Academic Emergency Medicine Consensus Conference Catalyzing System Change through Health Care Simulation: Systems, Competency, and Outcomes held in Orlando, Florida, on May 16, 2017, focused on the use of human factors (HF) and simulation in the field of emergency medicine (EM). The HF discipline is often underutilized within EM but has significant potential in improving the interface between technologies and individuals in the field. The discussion explored the domain of HF, its benefits in medicine, how simulation can be a catalyst for HF work in EM, and how EM can collaborate with HF professionals to effect change. Implementing HF in EM through health care simulation will require a demonstration of clinical and safety outcomes, advocacy to stakeholders and administrators, and establishment of structured collaborations between HF professionals and EM, such as in this breakout group

    Quality and reporting standards, resources, training materials and information for realist evaluation: the RAMESES II project

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    Background: Many of the problems confronting policy- and decision-makers, evaluators and researchers today are complex, as are the interventions designed to tackle them. Their success depends both on individuals’ responses and on the wider context of people’s lives. Realist evaluation tries to make sense of these complex interventions. It is a form of theory-driven evaluation, based on realist philosophy that aims to understand why these complex interventions work, how, for whom, in what context and to what extent. Objectives: Our objectives were to develop (a) quality standards, (b) reporting standards, (c) resources and training materials, (d) information and resources for patients and other lay participants and (e) to build research capacity among those interested in realist evaluation. Methods: To develop the quality and reporting standards, we undertook a thematic review of the literature, supplemented by our content expertise and feedback from presentations and workshops. We synthesised findings into briefing materials for realist evaluations for the Delphi panel (a structured method using experts to develop consensus). To develop our resources and training materials, we drew on our experience in developing and delivering education materials, feedback from the Delphi panel, the RAMESES JISCMail e-mail list, training workshops and feedback from training sessions. To develop information and resources for patients and other lay participants in realist evaluation, we convened a group consisting of patients and the public. We built research capacity by running workshops and training sessions. Results: Our literature review identified 152 realist evaluations, and when 37 of these had been analysed we were able to develop our briefing materials for the Delphi panel. The Delphi panel comprised 35 members from 27 organisations across six countries and five disciplines. Within three rounds, the panels had reached a consensus on 20 key reporting standards. The quality standards consist of eight criteria for realist evaluations. We developed resources and training materials for 15 theoretical and methodological topics. All resources are available online (www.ramesesproject.org). We provided methodological support to 17 projects and presentations or workshops to help build research capacity in realist evaluations to 29 organisations. Finally, we produced a generic patient information leaflet for lay participants in realist evaluations. Limitations: Our project had ambitious goals that created a substantial workload, leading to the need to prioritise objectives. For example, we truncated the literature review and focused on standards and training material development. Conclusions: Although realist evaluation holds much promise, misunderstandings and misapplications of it are common. We hope that our project’s outputs and activities will help to address these problems. Our resources are the start of an iterative journey of refinement and development of better resources for realist evaluations. The RAMESES II project seeks not to produce the last word on these issues, but to capture current expertise and establish an agreed state of the science. Much methodological development is needed in realist evaluation but this can take place only if there is a sufficient pool of highly skilled realist evaluators. Capacity building is the next key step in realist evaluation. Funding: The National Institute for Health Research Health Services and Delivery Research programme

    Streamlining Ground Station Network Compatibility Test for Small Satellites

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    A team of eight subject matter experts at NASA Goddard Space Flight Center (GSFC) completed a Lean Six Sigma project to identify process improvements for the compatibility test process for small satellites planning to use the NASA Near Earth Network (NEN). Ground station network compatibility testing is designed to reduce the risk to missions by resolving issues between the spacecraft's flight communication and navigation components and the ground systems prior to launch. Compatibility testing, which consists of a series of tests performed over a period of months and documented in reports, is an important step meant to prevent post-launch anomalies that could lead to expensive troubleshooting or mission failure. Compared to traditional missions, small satellite missions typically have a smaller budget and compressed schedules, which can result in small satellite projects' willingness to accept the risk associated with less comprehensive compatibility testing. Optimization and or refinement of the compatibility test process for small satellite missions could alleviate some of the pressures inherent with these factors. The goal of the Lean Six Sigma project was to develop alternative scalable methods of compatibility testing for small satellites. The Lean Six Sigma approach and the results of the project are reviewed in this paper

    Supporting the Quadruple Aim Using Simulation and Human Factors During COVID-19 Care

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    This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.The health care sector has made radical changes to hospital operations and care delivery in response to the coronavirus disease (COVID-19) pandemic. This article examines pragmatic applications of simulation and human factors to support the Quadruple Aim of health system performance during the COVID-19 era. First, patient safety is enhanced through development and testing of new technologies, equipment, and protocols using laboratory-based and in situ simulation. Second, population health is strengthened through virtual platforms that deliver telehealth and remote simulation that ensure readiness for personnel to deploy to new clinical units. Third, prevention of lost revenue occurs through usability testing of equipment and computer-based simulations to predict system performance and resilience. Finally, simulation supports health worker wellness and satisfaction by identifying optimal work conditions that maximize productivity while protecting staff through preparedness training. Leveraging simulation and human factors will support a resilient and sustainable response to the pandemic in a transformed health care landscape

    The association of antihypertensives with postural blood pressure and falls among seniors residing in the community : a case control study

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    Date of Acceptance: 22/07/2015 This article is protected by copyright. All rights reserved. Acknowledgements The authors declare that there is no conflict of interest,including specific financial interests and relationships and affiliations relevant to the subject of this manuscriptPeer reviewedPostprin

    Persistence of viral reservoirs in multiple tissues after antiretroviral therapy suppression in a macaque RT-SHIV model

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    Although antiretroviral therapy (ART) can suppress HIV-1 replication sufficiently to eliminate measurable plasma viremia, infected cells remain and ensure viral recrudescence after discontinuation of ART. We used a macaque model of HIV-1/AIDS to evaluate the location of infected cells during ART. Twelve macaques were infected with RT-SHIVmne, a SIV containing HIV-1 reverse transcriptase, conferring sensitivity to non-nucleoside reverse transcriptase inhibitors (NNRTIs). Ten to fourteen weeks post-infection, 6 animals were treated with 3 or 4 antiretroviral drugs for 17-20 weeks; 6 control animals remained untreated. Viral DNA (vDNA) and RNA (vRNA) were measured in peripheral blood mononuclear cells (PBMC) and at necropsy in multiple tissues by quantitative PCR and RT-PCR. The majority of virally infected cells were located in lymphoid tissues with variable levels in the gastrointestinal tract of both treated and untreated animals. Tissue viral DNA levels correlated with week 1 plasma viremia, suggesting that tissues that harbor proviral DNA are established within the first week of infection. PBMC vDNA levels did not correlate with plasma viremia or tissue levels of vDNA. vRNA levels were high in lymphoid and gastrointestinal tissues of the untreated animals; animals on ART had little vRNA expressed in tissues and virus could not be cultured from lymph node resting CD4+ cells after 17-20 weeks on ART, indicating little or no ongoing viral replication. Strategies for eradication of HIV-1 will need to target residual virus in ART suppressed individuals, which may not be accurately reflected by frequencies of infected cells in blood. © 2013 Kline et al

    HERON: Demonstrating a Novel Biological Platform for Small Satellite Missions

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    Long-duration deep space missions pose a significant health risk for both humans and their resident microorganisms. The GeneSat, PharmaSat and O/OREOS missions have previously explored biological questions regarding the effects of spaceflight on S. cerevisiase, B. subtilis, and E. coli. However, there currently exists both a knowledge and an accessibility gap in small satellite biological experiments. These payloads require precise instrumentation and complex platforms that are usually reserved for large research organizations. This makes it difficult for smaller organizations to perform biological research in low Earth orbit (LEO). To address these challenges, the University of Toronto Aerospace Team (UTAT) Space Systems Division is currently developing the HERON CubeSat. HERON houses a payload platform which measures the effects of the LEO environment on the gene expression and drug resistance of Candida albicans, a yeast commonly found in the human gut microbiome. Previous research has suggested that C. albicans might display increased pathogenicity and drug resistance in response to microgravity, which has important implications for long-duration human spaceflight. The yeast cells are housed in custom acrylic microfluidics chips containing 32 wells with channels for media and drug delivery. A measurement printed circuit board (PCB) contains custom optics capable of measuring minute changes in cell fluorescence. The entire payload stack is then housed in a temperature- and humidity-controlled 2U pressure vessel. Space Systems as a whole is an undergraduate student-led and student-funded design team, dedicated to the development of small satellite missions with a focus on education and undergraduate learning. HERON is scheduled to launch Q1 2022 into a Sun-synchronous orbit via a SpaceX Falcon 9 rocket at an altitude of approximately 550 km. Our platform is open-source and can serve as a low-cost template for future biological CubeSat missions. This paper serves as a technical and scientific description of the platform, along with the lessons learned during the payload design, assembly, and validation processes
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