This is the first study to look at the possibility of detecting HCC from breath using canine olfaction. Our results show that this is possible with an accuracy of 78% (p < 0.001 when compared to chance alone), and are thus a proof of concept. Further refinement of the process of detection will be needed before clinical application.
At a fraction the total cost of an equivalent orbital mission, scientific balloon-borne platforms, operating above 99.7% of the Earth's atmosphere, offer attractive, competitive, and effective observational capabilities -namely space-like resolution, transmission, and backgrounds -that are well suited for modern astronomy and cosmology. SUPERBIT is a diffraction-limited, wide-field, 0.5 m telescope capable of exploiting these observing conditions in order to provide exquisite imaging throughout the near-IR to near-UV. It utilizes a robust active stabilization system that has consistently demonstrated a 1σ sky-fixed pointing stability at 48 milliarcseconds over multiple 1 hour observations at float. This is achieved by actively tracking compound pendulations via a three-axis gimballed platform, which provides sky-fixed telescope stability at < 500 milliarcseconds and corrects for field rotation, while employing high-bandwidth tip/tilt optics to remove residual disturbances across the science imaging focal plane. SUPERBIT's performance during the 2019 commissioning flight benefited from a customized high-fidelity science-capable telescope designed with exceptional thermo-and opto-mechanical stability as well as tightly constrained static and dynamic coupling between high-rate sensors and telescope optics. At the currently demonstrated level of flight performance, SUPERBIT capabilities now surpass the science requirements for a wide variety of experiments in cosmology, astrophysics and stellar dynamics.
This paper presents optical night sky brightness measurements from the stratosphere using CCD images taken with the Super-pressure Balloon-borne Imaging Telescope (SuperBIT). The data used for estimating the backgrounds were obtained during three commissioning flights in 2016, 2018, and 2019 at altitudes ranging from 28 to 34 km above sea level. For a valid comparison of the brightness measurements from the stratosphere with measurements from mountain-top ground-based observatories (taken at zenith on the darkest moonless night at high Galactic and high ecliptic latitudes), the stratospheric brightness levels were zodiacal light and diffuse Galactic light subtracted, and the airglow brightness was projected to zenith. The stratospheric brightness was measured around 5.5 hr, 3 hr, and 2 hr before the local sunrise time in 2016, 2018, and 2019, respectively. The B, V, R, and I brightness levels in 2016 were 2.7, 1.0, 1.1, and 0.6 mag arcsec −2 darker than the darkest ground-based measurements. The B, V, and R brightness levels in 2018 were 1.3, 1.0, and 1.3 mag arcsec −2 darker than the darkest ground-based measurements. The U and I brightness levels in 2019 were 0.1 mag arcsec −2 brighter than the darkest ground-based measurements, whereas the B and V brightness levels were 0.8 and 0.6 mag arcsec −2 darker than the darkest ground-based measurements. The lower sky brightness levels, stable photometry, and lower atmospheric absorption make stratospheric observations from a balloon-borne platform a unique tool for astronomy. We plan to continue this work in a future midlatitude long duration balloon flight with SuperBIT.Unified Astronomy Thesaurus concepts: CCD photometry (208); Night sky brightness (1112); Sky brightness (1462); Stratosphere (1640); High altitude balloons (738); Optical observatories (1170); Diffuse radiation (383); Gegenschein (640)
Due to the limited number of photons, directly imaging planets requires long integration times. The wavefront must be stable on the same time scale which is often difficult in space due to thermal variations and vibrations. In this paper, we discuss the results of implementing a dark hole maintenance (DHM) algorithm (Pogorelyuk et. al. 2019) 1 on the High-contrast imager for Complex Aperture Telescopes (HiCAT) at the Space Telescope Science Institute (STScI). The testbed contains a pair of deformable mirrors (DMs) and a lyot coronagraph. The algorithm uses an Extended Kalman Filter (EKF) and DM dithering to predict the drifting electric field in the dark hole along with Electric Field Conjugation to cancel out the drift. The DM dither introduces phase diversity which ensures the EKF converges to the correct value. The DHM algorithm maintains an initial contrast of 8.5 × 10 −8 for 6 hrs in the presence of the DM actuator random walk drift with a standard deviation of 1.7 × 10 −3 nm/s.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.