189 research outputs found

    Investigating the Effect of Stratospheric Radiation on Seed Germination and Growth

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    Three seed types: bean (Phaseolus vulgaris), corn (Zea mays) and radish (Raphanus sativus) were flown in a high altitude weather balloon into the mid-stratosphere to investigate the effects of high altitude radiation on germination success and seedling growth. After recovering and planting the seeds, the bean seeds showed lower germination success with exposure to high altitude radiation, and consequently stunted seedling growth. Cord and radish seeds experienced a statistically significant positive effect on germination success form radiation exposure compared to control seeds, but negative effect on seedling growth. Overall, the field experiments presented here support laboratory studies that show radiation exposure on vegetable seeds has a mixed effect on the germination success and negative effect on seedling growth on investigated seed types

    Spherical Panoramic Image Payload Design for Stratospheric Ballooning

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    The 2017 total solar eclipse inspired innovation in design and implementation in stratospheric ballooning techniques and payloads to fully document the unique near-space experience. The Arkansas BalloonSAT team, as part of the Eclipse Ballooning Project, designed and fabricated a spherical panoramic image payload using computer aided design (CAD) software to capture images of the eclipse from the high altitude balloon. The light, durable, and water resistant mount consisted of a polyurethane-coated UV-resin based enclosure that housed six Hero 4 Session GoPro cameras, and a relative inertial measurement unit (IMU) PCB equipped with GPS. The cameras’ lenses faced radially outward on the six faces of a cube. The IMU/GPS PCB system computed the absolute orientation of the cameras, which allows the time-lapse pictures to be stitched together into a relatively stable spherical video. The batteries for this system experienced a voltage drop during flight as the payload temperature dropped below -60 degrees Celsius resulting in an auto-shutdown procedure disabling the system before eclipse totality. Future designs for this model will include a temperature regulation or insulation system to prevent this voltage drop

    Models of Models: The Symbiotic Relationship between Models and Wargames

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    Military planning uses wargames to model the processes and decisions of an operation. As these operations become increasingly complex, the wargames similarly become more complex. Complex wargames are difficult to design and execute. As such, computer-based modeling and simulation can aid the wargame development, ensuring smooth execution. In particular, computer-based modeling and simulation can develop and validate the processes, determine initial conditions, evaluate the rules, and aid in validation. In turn, the wargame can provide useful data that can be fed into detailed models that can provide quantitative analysis to decision-makers

    Factors influencing quality of life following lower limb amputation for peripheral arterial occlusive disease: a systematic review of the literature

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    Background: The majority of lower limb amputations are undertaken in people with peripheral arterial occlusive disease,\ud and approximately 50% have diabetes. Quality of life is an important outcome in lower limb amputations; little is known\ud about what influences it, and therefore how to improve it.\ud Objectives: The aim of this systematic review was to identify the factors that influence quality of life after lower limb\ud amputation for peripheral arterial occlusive disease.\ud Methods: MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science and Cochrane databases were searched to identify\ud articles that quantitatively measured quality of life in those with a lower limb amputation for peripheral arterial occlusive\ud disease. Articles were quality assessed by two assessors, evidence tables summarised each article and a narrative\ud synthesis was performed.\ud Study design: Systematic review.\ud Results: Twelve articles were included. Study designs and outcome measures used varied. Quality assessment scores\ud ranged from 36% to 92%. The ability to walk successfully with a prosthesis had the greatest positive impact on quality\ud of life. A trans-femoral amputation was negatively associated with quality of life due to increased difficulty in walking\ud with a prosthesis. Other factors such as older age, being male, longer time since amputation, level of social support and\ud presence of diabetes also negatively affected quality of life.\ud Conclusion: Being able to walk with a prosthesis is of primary importance to improve quality of life for people with lower\ud limb amputation due to peripheral arterial occlusive disease. To further understand and improve the quality of life of this\ud population, there is a need for more prospective longitudinal studies, with a standardised outcome measure
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