3,211 research outputs found

    Development and application of a local linearization algorithm for the integration of quaternion rate equations in real-time flight simulation problems

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    High angular rates encountered in real-time flight simulation problems may require a more stable and accurate integration method than the classical methods normally used. A study was made to develop a general local linearization procedure of integrating dynamic system equations when using a digital computer in real-time. The procedure is specifically applied to the integration of the quaternion rate equations. For this application, results are compared to a classical second-order method. The local linearization approach is shown to have desirable stability characteristics and gives significant improvement in accuracy over the classical second-order integration methods

    Temporal Trends in Incidence, Sepsis-Related Mortality, and Hospital-Based Acute Care After Sepsis.

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    OBJECTIVES: A growing number of patients survive sepsis hospitalizations each year and are at high risk for readmission. However, little is known about temporal trends in hospital-based acute care (emergency department treat-and-release visits and hospital readmission) after sepsis. Our primary objective was to measure temporal trends in sepsis survivorship and hospital-based acute care use in sepsis survivors. In addition, because readmissions after pneumonia are subject to penalty under the national readmission reduction program, we examined whether readmission rates declined after sepsis hospitalizations related to pneumonia. DESIGN AND SETTING: Retrospective, observational cohort study conducted within an academic healthcare system from 2010 to 2015. PATIENTS: We used three validated, claims-based approaches to identify 17,256 sepsis or severe sepsis hospitalizations to examine trends in hospital-based acute care after sepsis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: From 2010 to 2015, sepsis as a proportion of medical and surgical admissions increased from 3.9% to 9.4%, whereas in-hospital mortality rate for sepsis hospitalizations declined from 24.1% to 14.8%. As a result, the proportion of medical and surgical discharges at-risk for hospital readmission after sepsis increased from 2.7% to 7.8%. Over 6 years, 30-day hospital readmission rates declined modestly, from 26.4% in 2010 to 23.1% in 2015, driven largely by a decline in readmission rates among survivors of nonsevere sepsis, and nonpneumonia sepsis specifically, as the readmission rate of severe sepsis survivors was stable. The modest decline in 30-day readmission rates was offset by an increase in emergency department treat-and-release visits, from 2.8% in 2010 to a peak of 5.4% in 2014. CONCLUSIONS: Owing to increasing incidence and declining mortality, the number of sepsis survivors at risk for hospital readmission rose significantly between 2010 and 2015. The 30-day hospital readmission rates for sepsis declined modestly but were offset by a rise in emergency department treat-and-release visits

    Plasticity facilitates sustainable growth in the commons

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    In the commons, communities whose growth depends on public goods, individuals often rely on surprisingly simple strategies, or heuristics, to decide whether to contribute to the common good (at risk of exploitation by free-riders). Although this appears a limitation, here we show how four heuristics lead to sustainable growth by exploiting specific environmental constraints. The two simplest ones --contribute permanently or switch stochastically between contributing or not-- are first shown to bring sustainability when the public good efficiently promotes growth. If efficiency declines and the commons is structured in small groups, the most effective strategy resides in contributing only when a majority of individuals are also contributors. In contrast, when group size becomes large, the most effective behavior follows a minimal-effort rule: contribute only when it is strictly necessary. Both plastic strategies are observed in natural systems what presents them as fundamental social motifs to successfully manage sustainability

    “I see my culture starting to disappear”: Anishinaabe perspectives on the socioecological impacts of climate change and future research needs

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    Climate change disproportionately affects Indigenous Peoples because of strong connections between environmental, cultural, and spiritual well-being. While much of the global discourse surrounding climate change is founded in Western science, the holistic, place-based knowledge of Indigenous Peoples offers a complementary way of understanding and mitigating climate change impacts. The goal of this research was to elevate Anishinaabe concerns, observations, and perspectives about climate change impacts and future research needs. We organized a workshop called “Connecting Guardians in a Changing World” where participants shared concerns about animal and plant life cycles, water cycles and water quality, and impacts to ways of life, including reduced capacity to perform cultural practices and erosion of their knowledge. Participants highlighted the challenge of prioritizing a single impact of climate change, emphasizing that impacts to the environment and ways of life are interconnected. Participants also expressed the need for research and policy that move beyond interdisciplinarity to include intercultural philosophy and research that better reflects Indigenous worldviews and incorporates Indigenous methodologies. Moving forward, meaningful partnerships and opportunities for knowledge sharing should be prioritized in climate change discourse to ensure solutions are generated together, with all of the tools and knowledge available

    Adenovirus infection in the lung results in graft failure after lung transplantation

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    AbstractObjectives: Our goal was to examine the relationship between viral pneumonia and outcome in pediatric patients undergoing lung or heart-lung transplantation. Methods: Prospective surveillance for common respiratory viruses of childhood was performed in all patients undergoing lung or heart-lung transplantation. Specimens were examined for the presence of replicating virus (by culture), viral genome (by polymerase chain reaction), and viral antigen (by immunofluorescence and immunohistochemical staining). The relationship between viral infection and outcome was examined. Results: Sixteen patients underwent 19 transplants during the study period, with follow-up of 1 to 26 months. Virus was identified in the transplanted lung in 29 instances; adenovirus was identified most commonly (8/16 patients) and had the greatest impact on outcome. In 2 patients with early, fulminant infection, adenovirus was also identified in the donor. Adenovirus was significantly associated with respiratory failure leading to death or graft loss and with the histologic diagnosis of obliterative bronchiolitis (P ≤ .002 in each case). Conclusions: Adenovirus infection in the transplanted lung is significantly associated with graft failure, histologic obliterative bronchiolitis, and death. Health care personnel and families must be vigilant in preventing exposure of transplant recipients to this virus. Availability of a rapid and reliable test for adenovirus in donors and recipients would have an impact on management and could improve outcome for pediatric lung recipients. (J Thorac Cardiovasc Surg 1998;116:617-23

    Evolutionary Roots of Property Rights; The Natural and Cultural Nature of Human Cooperation

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    Debates about the role of natural and cultural selection in the development of prosocial, antisocial and socially neutral mechanisms and behavior raise questions that touch property rights, cooperation, and conflict. For example, some researchers suggest that cooperation and prosociality evolved by natural selection (Hamilton 1964, Trivers 1971, Axelrod and Hamilton 1981, De Waal 2013, 2014), while others claim that natural selection is insufficient for the evolution of cooperation, which required in addition cultural selection (Sterelny 2013, Bowles and Gintis 2003, Seabright 2013, Norenzayan 2013). Some scholars focus on the complexity and hierarchical nature of the evolution of cooperation as involving different tools associated with lower and the higher levels of competition (Nowak 2006, Okasha 2006); others suggest that humans genetically inherited heuristics that favor prosocial behavior such as generosity, forgiveness or altruistic punishment (Ridley 1996, Bowles and Gintis 2004, Rolls 2005). We argue these mechanisms are not genetically inherited; rather, they are features inherited through cultural selection. To support this view we invoke inclusive fitness theory, which states that individuals tend to maximize their inclusive fitness, rather than maximizing group fitness. We further reject the older notion of natural group selection - as well as more recent versions (West, Mouden, Gardner 2011) – which hold that natural selection favors cooperators within a group (Wynne-Edwards 1962). For Wynne-Edwards, group selection leads to group adaptations; the survival of individuals therefore depends on the survival of the group and a sharing of resources. Individuals who do not cooperate, who are selfish, face extinction due to rapid and over-exploitation of resources

    High-Energy Proton Testing of Sensitive Electronics for use on Modular Infrared Molecules and Ices Sensor (MIRMIS) Instrument

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    The Comet Interceptor (CI) mission is ESA\u27s first F class mission, selected in June 2019. This mission consists of three spacecraft: Spacecraft A (main spacecraft), Spacecraft B1 (supplied by the Japanese space agency JAXA), and Spacecraft B2. In this paper, we highlight the Modular Infrared Molecular and Ices Sensor (MIRMIS) instrument, which is integrated into the CI Spacecraft A\u27s scientific payload. In addition to hardware contributions from Finland (VTT Finland) and the UK (University of Oxford), the MIRMIS instrument team includes members from the University of Helsinki and NASA\u27s Goddard Space Flight Centre. MIRMIS covers the spectral range of 0.9 to ~25 μm. This paper presents the preliminary high-proton-energy radiation test results of MIRMIS’ near-infrared detector arraysensitive electronic components. Proton beam testing is performed to estimate Single Event Effects (SEE) on the PCB boards and SEE and Total Non-Ionizing Dose (TNID)/ Displacement Damage (DD) on the detectors. The tests were conducted at the Paul Scherrer Institute (PSI) Proton Irradiation Facility (PIF), Villigen, Switzerland. The levels for the tests were based on the mission requirements for the ESA Comet Interceptor mission: 3 years (at 1 AU- Segment 1) and 2 years (at 0.9 AU- Segment 2). The DD levels from the analysis were equivalent to 1e11 protons/cm2 with an energy of 50 MeV. The electronics are exposed to high-energy protons causing Single Event Effects (SEE) which may induce potentially destructive and non-destructive effects. The test items primarily included the InGaAs image sensors (SCD Cardinal640, standard and low noise), Xilinx Spartan-6 FPGAs (Field Programmable Gate Arrays), and other proximity electronics. The proton energies were varied from 50 to 200 MeV, at fluxes of 106 to 108 particles/cm2/s. No events were observed on the standard Cardinal640 sensor at target fluences between 1.00E+10 to 1.00E+11 particles/cm2. FPGAs did not show any susceptibility to TNID at fluences up to 1.00E+11 (particles/cm2)

    The Cosmic Ray Muon Flux at WIPP

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    In this work a measurement of the muon intensity at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, NM, USA is presented. WIPP is a salt mine with a depth of 655 m. The vertical muon flux was measured with a two panels scintillator coincidence setup to Phi_{vert}=3.10(+0.05/-0.07)*10^(-7)s^(-1)cm^(-2)sr^(-1).Comment: 18 pages, p figure

    Hyperspectral Imager for the Coastal Ocean (HICO): Overview, Operational Updates, and Coastal Ocean Applications

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    The Hyperspectral Imager for the Coastal Ocean (HICO) was built to measure inwater properties of complex coastal regions. HICO enables synoptic coverage; 100meter spatial resolution for sampling the variability and spatial irregularity of coastal waters; and high spectral resolution to untangle the signals from chlorophyll, colored dissolved organic matter, suspended sediments and varying bottom types. HICO was built by the Naval Research Laboratory, installed on the International Space Station (ISS) in September 2009, and operated for ONR for the first three years. In 2013, NASA assumed sponsorship of operations in order to leverage HICO's ability to address their Earth monitoring mission. This has opened up access of HICO data to the broad research community. Over 8000 images are now available on NASA's Ocean Color Website (http://oceancolor.gsfc.nasa.gov/cgi/browse.pl?sen=hi). Oregon State University's HICO website (http://hico.coas.oregonstate.edu) remains the portal for researchers to request new collections and access their requested data. We will present updates on HICO's calibration and improvements in geolocation and show examples of the use of HICO data to address issues in the coastal ocean and Great Lakes

    Targeting Hospitalized Patients for Early Discharge Planning Intervention

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    The purpose of the study was to describe the ability of an evidence-based discharge planning decision support tool to identify and prioritize patients appropriate for early discharge planning intervention. Specifically we aimed to determine whether patients with a high Early Screen for Discharge Planning (ESDP) score report more problems and continuing care needs in the first few weeks after discharge than patients with low ESDP scores
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