375 research outputs found

    Large capacity oblique all-wing transport aircraft

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    Dr. R. T. Jones first developed the theory for oblique wing aircraft in 1952, and in subsequent years numerous analytical and experimental projects conducted at NASA Ames and elsewhere have established that the Jones' oblique wing theory is correct. Until the late 1980's all proposed oblique wing configurations were wing/body aircraft with the wing mounted on a pivot. With the emerging requirement for commercial transports with very large payloads, 450-800 passengers, Jones proposed a supersonic oblique flying wing in 1988. For such an aircraft all payload, fuel, and systems are carried within the wing, and the wing is designed with a variable sweep to maintain a fixed subsonic normal Mach number. Engines and vertical tails are mounted on pivots supported from the primary structure of the wing. The oblique flying wing transport has come to be known as the Oblique All-Wing (OAW) transport. This presentation gives the highlights of the OAW project that was to study the total concept of the OAW as a commercial transport

    Clinical Registries Could Improve Influenza Like Illness and COVID-19 Surveillance

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    Capacity for tracking COVID-19 prevalence patterns is hampered by insufficient data, particularly from rural and small communities. The PRIME Registry holds data for 5.4 million patients in 47 states who made 638,983 Influenza-Like Illness (ILI) visits in 2019, mirroring CDC’s ILINet temporal patterns but with higher volume and greater rural penetration. Clinical data registries are viable partners that could fill gaps for epidemic sentinel functions and have rich patient data which may identify factors predictive of COVID-19 morbidity and mortality.https://deepblue.lib.umich.edu/bitstream/2027.42/154853/1/ILI-PRIME_AnnalsFamMed_FINAL.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154853/2/RehkopfILIFig1.docxhttps://deepblue.lib.umich.edu/bitstream/2027.42/154853/3/RehkopfILIFig2.docxDescription of ILI-PRIME_AnnalsFamMed_FINAL.pdf : Main ArticleDescription of RehkopfILIFig1.docx : Figure 1Description of RehkopfILIFig2.docx : Figure

    The Impact of Climate Change on Virginia\u27s Coastal Areas

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    As part of HJ47/SJ47 (2020), the Virginia General Assembly directed the Joint Commission on Technology and Science (JCOTS) to study the “safety, quality of life, and economic consequences of weather and climate-related events on coastal areas in Virginia.” In pursuit of this goal, the commission was to “accept any scientific and technical assistance provided by the nonpartisan, volunteer Virginia Academy of Science, Engineering, and Medicine (VASEM). VASEM convened an expert study board with representation from the Office of the Governor, planning district commissions in coastal Virginia, The Port of Virginia, the Virginia Economic Development Partnership, state universities, private industry, and law firms. In producing the report, the board followed methods similar to those used by the National Academies of Science, Engineering, and Medicine by convening an expert committee tasked with studying and reporting on the topic. As a result, the report represents the views and perspectives of the study board members but was not submitted for public review or comment. This report is the product of those efforts. It finds that climate change will have an increasingly disruptive effect on people living in Virginia’s coastal areas during the 21st century — and that these disruptions will have repercussions across the Commonwealth. It includes an explanation of the physical forces driving climate change, an analysis of the current and projected effects of climate change on the Commonwealth, perspectives that legislators might consider as they face these challenges, and recommendations that could help Virginia implement more productive and effective strategies to address them

    Systematic review of reduced therapy regimens for children with low risk febrile neutropenia

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    PURPOSE: Reduced intensity therapy for children with low-risk febrile neutropenia may provide benefits to both patients and the health service. We have explored the safety of these regimens and the effect of timing of discharge. METHODS: Multiple electronic databases, conference abstracts and reference lists were searched. Randomised controlled trials (RCT) and prospective observational cohorts examining the location of therapy and/or the route of administration of antibiotics in people younger than 18 years who developed low-risk febrile neutropenia following treatment for cancer were included. Meta-analysis using a random effects model was conducted. I (2) assessed statistical heterogeneity not due to chance. Registration: PROSPERO (CRD42014005817). RESULTS: Thirty-seven studies involving 3205 episodes of febrile neutropenia were included; 13 RCTs and 24 prospective observational cohorts. Four safety events (two deaths, two intensive care admissions) occurred. In the RCTs, the odds ratio for treatment failure (persistence, worsening or recurrence of fever/infecting organisms, antibiotic modification, new infections, re-admission, admission to critical care or death) with outpatient treatment was 0.98 (95% confidence interval (95%CI) 0.44-2.19, I (2) = 0 %) and with oral treatment was 1.05 (95%CI 0.74-1.48, I (2) = 0 %). The estimated risk of failure using outpatient therapy from all prospective data pooled was 11.2 % (95%CI 9.7-12.8 %, I (2) = 77.2 %) and using oral antibiotics was 10.5 % (95%CI 8.9-12.3 %, I (2) = 78.3 %). The risk of failure was higher when reduced intensity therapies were used immediately after assessment, with lower rates when these were introduced after 48 hours. CONCLUSIONS: Reduced intensity therapy for specified groups is safe with low rates of treatment failure. Services should consider how these can be acceptably implemented

    Lorentz and CPT tests with spin-polarized solids

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    Experiments using macroscopic samples of spin-polarized matter offer exceptional sensitivity to Lorentz and CPT violation in the electron sector. Data from existing experiments with a spin-polarized torsion pendulum provide sensitivity in this sector rivaling that of all other existing experiments and could reveal spontaneous violation of Lorentz symmetry at the Planck scale.Comment: 4 pages, accepted for publication in Physical Review Letter

    Estimating stable isotope turnover rates of epidermal mucus and dorsal muscle for an omnivorous fish using a diet-switch experiment

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    © 2018, The Author(s). Stable isotope (SI) analysis studies rely on knowledge of isotopic turnover rates and trophic-step discrimination factors. Epidermal mucus (‘mucus’) potentially provides an alternative SI ‘tissue’ to dorsal muscle that can be collected non-invasively and non-destructively. Here, a diet-switch experiment using the omnivorous fish Cyprinus carpio and plant- and fish-based formulated feeds compared SI data between mucus and muscle, including their isotopic discrimination factors and turnover rates (as functions of time T and mass G, at isotopic half-life (50) and equilibrium (95)). Mucus isotope data differed significantly and predictively from muscle data. The fastest δ13C turnover rate was for mucus in fish on the plant-based diet (T50: 17 days, T95: 74 days; G50: 1.08(BM), G95: 1.40(BM)). Muscle turnover rates were longer for the same fish (T50: 44 days, T95: 190 days; G50: 1.13(BM), G95: 1.68(BM)). Longer half-lives resulted in both tissues from the fish-based diet. δ13C discrimination factors varied by diet and tissue (plant-based: 3.11–3.28‰; fishmeal: 1.28–2.13‰). Mucus SI data did not differ between live and frozen fish. These results suggest that mucus SI half-lives provide comparable data to muscle, and can be used as a non-destructive alternative tissue in fish-based SI studies

    Coordination in climbing: effect of skill, practice and constraints manipulation

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    BACKGROUND: Climbing is a physical activity and sport involving many subdisciplines. Minimization of prolonged pauses, use of a relatively simple path through a route and smooth transitions between movements broadly define skilled coordination in climbing. OBJECTIVES: To provide an overview of the constraints on skilled coordination in climbing and to explore future directions in this emerging field. METHODS: A systematic literature review was conducted in 2014 and retrieved studies reporting perceptual and movement data during climbing tasks. To be eligible for the qualitative synthesis, studies were required to report perceptual or movement data during climbing tasks graded for difficulty. RESULTS: Qualitative synthesis of 42 studies was carried out, showing that skilled coordination in climbing is underpinned by superior perception of climbing opportunities; optimization of spatial-temporal features pertaining to body-to-wall coordination, the climb trajectory and hand-to-hold surface contact; and minimization of exploratory behaviour. Improvements in skilled coordination due to practice are related to task novelty and the difficulty of the climbing route relative to the individual's ability level. CONCLUSION: Perceptual and motor adaptations that improve skilled coordination are highly significant for improving the climbing ability level. Elite climbers exhibit advantages in detection and use of climbing opportunities when visually inspecting a route from the ground and when physically moving though a route. However, the need to provide clear guidelines on how to improve climbing skill arises from uncertainties regarding the impacts of different practice interventions on learning and transfer

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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