158 research outputs found

    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

    Observing the 2017 Total Solar Eclipse in the skies above Central Missouri, USA

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    We report the work and findings of Arkansas BalloonSAT in participating in the 2017 Eclipse Ballooning Project. Arkansas BalloonSAT was the site-team for Missouri and launched a high altitude balloon from Fulton High School in Fulton, MO an hour prior to totality. This balloon reached an apogee of 24 kilometers shortly after floating for one minute in the moon\u27s umbra. In addition to live-streaming video from one payload as part of the Eclipse Ballooning Project, our mission included carrying a scientific payload and educational outreach. This report will summarize those efforts and include an examination of balloon kinematics with the cooling effect of the moon\u27s umbra and aircraft-balloon interaction. We further discuss developments in the system to minimize payload size for future eclipse studies

    Dexamethasone therapy in COVID-19 patients:implications and guidance for the management of blood glucose in people with and without diabetes

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    The RECOVERY (Randomised Evaluation of COVid-19 thERapY) trial found that dexamethasone 6 mg once per day for 10 days reduced deaths by one-third in ventilated patients and by one-fifth in other patients, receiving oxygen therapy. This equates to the prevention of one death in around eight ventilated patients, or one in around 25 patients requiring oxygen

    Paradoxical patterns of sinusoidal obstruction syndrome-like liver injury in aged female CD-1 mice triggered by cannabidiol-rich cannabis extract and acetaminophen co-administration

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    © 2019 The Authors. Environmental Toxicology published by Wiley Periodicals, Inc. Exposure to environmental contaminants and consumption of a high, saturated fatty diet has been demonstrated to promote precursors for metabolic syndrome (hyperglycemia, hyperinsulinemia, and hypertriglyceridemia). The purpose of this study was to determine if exposure to the most prevalent environmental persistent organic pollutants (POPs) would act as causative agents to promote metabolic syndrome independent of dietary intake. We hypothesized that POPs will activate the advanced glycated end-product (AGE)-and receptor for AGE (RAGE) signaling cascade to promote downstream signaling modulators of cardiovascular remodeling and oxidative stress in the heart. At 5-weeks of age nondiabetic (WT) and diabetic (ob/ob) mice were exposed POPs mixtures by oral gavage twice a week for 6-weeks. At the end of 6-weeks, animals were sacrificed and the hearts were taken for biochemical analysis. Increased activation of the AGE-RAGE signaling cascade via POPs exposure resulted in elevated levels of fibroblast differentiation (α-smooth muscle actin) and RAGE expression indicated maladaptive cardiac remodeling. Conversely, the observed decreased superoxide dismutase-1 and -2 (SOD-1 and SOD-2) expression may exacerbate the adverse changes occurring as a result of POPs treatment to reduce innate cardioprotective mechanisms. In comparison, ventricular collagen levels were decreased in mice exposed to POPs. In conclusion, exposure to organic environmental pollutants may intensify oxidative and inflammatory stressors to overwhelm protective mechanisms allowing for adverse cardiac remodeling

    Initial experience of a large, self-expanding, and fully recapturable transcatheter aortic valve: The UK & Ireland Implanters' registry.

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    OBJECTIVES: The UK & Ireland Implanters' registry is a multicenter registry which reports on real-world experience with novel transcatheter heart valves. BACKGROUND: The 34 mm Evolut R transcatheter aortic valve is a self-expanding and fully recapturable transcatheter aortic valve, designed to treat patients with a large aortic annulus. METHODS: Between January 2017 and April 2018, clinical, procedural and 30-day outcome data were prospectively collected from all patients receiving the 34 mm Evolut R valve across 17 participating centers in the United Kingdom and Ireland. The primary efficacy outcome was the Valve Academic Research Consortium-2(VARC-2)-defined endpoint of device success. The primary safety outcome was the VARC-2-defined composite endpoint of early safety at 30 days. RESULTS: A total of 217 patients underwent attempted implant. Mean age was 79.5 ± 8.8 years and Society of Thoracic Surgeons Predicted Risk of Mortality Score 5.2% ± 3.4%. Iliofemoral access was used in 91.2% of patients. Device success was 79.7%. Mean gradient was 7.0 ± 4.6 mmHg and effective orifice area 2.0 ± 0.6 cm2 . Paravalvular regurgitation was more than mild in 7.2%. A new permanent pacemaker was implanted in 15.7%. Early safety was demonstrated in 91.2%. At 30 days, all-cause mortality was 3.2%, stroke 3.7%, and major vascular complication 2.3%. CONCLUSIONS: Real-world experience of the 34 mm Evolut R transcatheter aortic valve demonstrated acceptable procedural success, safety, valve function, and incidence of new permanent pacemaker implantation

    Assessing the Effects of Personal Characteristics and Context on U.S. House Speakers’ Leadership Styles, 1789-2006

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    Research on congressional leadership has been dominated in recent decades by contextual interpretations that see leaders’ behavior as best explained by the environment in which they seek to exercise leadership—particularly, the preference homogeneity and size of their party caucus. The role of agency is thus discounted, and leaders’ personal characteristics and leadership styles are underplayed. Focusing specifically on the speakers of the U.S. House of Representatives from the first to the 110th Congress, we construct measures of each speaker’s commitment to comity and leadership assertiveness. We find the scores reliable and then test the extent to which a speaker’s style is the product of both political context and personal characteristics. Regression estimates on speakers’ personal assertiveness scores provide robust support for a context-plus-personal characteristics explanation, whereas estimates of their comity scores show that speakers’ personal backgrounds trump context
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