Pilot Visual Detection of Small Unmanned Aircraft Systems (sUAS) Equipped with Strobe Lighting

When operating under Visual Flight Rules, pilots primarily rely on visual scanning to avoid other aircraft and airborne collision threats. Records from the Federal Aviation Administration indicate that near encounters with unmanned aircraft are on the rise, reaching 1,761 reported unmanned aircraft system (UAS) sightings or near-misses in 2016. This study sought to assess the effectiveness of pilot visual detection of UAS platforms that were equipped with strobe lighting. A sample of 10 pilots flew a general aviation aircraft on a scripted series of five intercepts with a small UAS (sUAS) that was equipped with strobe lighting. Participants were asked to indicate when they visually detected the unmanned aircraft. Geolocation information for both the aircraft and sUAS platform was compared to assess visibility distance. Findings were used to evaluate the efficacy of daytime strobe lighting as a method to enhance pilot sUAS detection, visibility, and collision avoidance. Participants detected the unmanned aircraft during 7.7% of the intercepts. Due to a lack of data points, the authors were unable to conclusively determine if strobe lighting improved UAS visual detection. The authors recommend further research to explore the effectiveness of using sUAS-mounted strobe lights for nighttime visual detection

Detecting and Assessing Collision Potential of Aircraft and Small Unmanned Aircraft Systems (sUAS) by Visual Observers

Visual observers are used to assist the Remote Pilot with maintaining sight of the unmanned aircraft as well as scanning the surrounding airspace for potential collision hazards. The purpose of this study was to examine the effectiveness of visual observers in detecting an intruding general aviation aircraft approaching the small unmanned aircraft system (sUAS) operations area. The study sought to determine the effectiveness of sUAS visual observers in detecting a general aviation aircraft collision hazard with a sUAS. Ten participants were asked to perform visual observer duties in support of a sUAS operation. Participants were asked to indicate when they were able to hear and see an aircraft that conducted a scripted series of close intercepts with a sUAS. Additionally, researchers assessed each visual observer’s ability to accurately judge the closure rate of the aircraft, by estimating the duration from initial sighting until the aircraft would intercept the airborne sUAS platform. Geolocation data from both the aircraft and sUAS were time correlated and compared to determine estimation accuracy. Findings were used to formulate operational recommendations to improve visual observer performance in detecting and assessing intruder aircraft collision potential

Cyclic AMP activates B-Raf and ERK in cyst epithelial cells from autosomal-dominant polycystic kidneys

Cyclic AMP activates B-Raf and ERK in cyst epithelial cells from autosomal-dominant polycystic kidneys.BackgroundThe proliferation of mural epithelial cells is a major cause of progressive cyst enlargement in autosomal-dominant polycystic kidney disease (ADPKD). Adenosine 3′, 5′ cyclic monophosphate (cAMP) stimulates the proliferation of cells from ADPKD cysts, but not cells from normal human kidney cortex (HKC), through the activation of protein kinase A (PKA), mitogen-activated protein kinase kinase (MEK), and extracellular signal-regulated kinase (ERK/MAPK). In the current study, we examined the signaling pathway between PKA and MEK in ADPKD and HKC cells.MethodsPrimary cultures of human ADPKD and HKC cells were prepared from nephrectomy specimens. We determined the effects of cAMP and epidermal growth factor (EGF) on the activation of ERK, B-Raf and Raf-1 in ADPKD and HKC cells by immune kinase assay and Western blot.Results8-Br-cAMP increased phosphorylated ERK (2.7- ± 0.6-fold, N = 7), and B-Raf kinase activity (3.6- ± 1.1-fold, N = 5) in cells from ADPKD kidneys; levels of phosphorylated Raf-1 were not changed. Inhibition of PKA by H89 strikingly decreased cAMP-stimulated phosphorylation of ERK and B-Raf, and MAPK inhibition by PD98059 blocked the effect of the nucleotide to activate ERK. By contrast, in HKC cells 8-Br-cAMP did not activate B-Raf and ERK. EGF stimulated the phosphorylation of ERK and Raf-1 in both ADPKD and HKC cells, but had no effect on B-Raf. 8-Br-cAMP and EGF conjointly increased ERK activation above that of either agonist alone in ADPKD cells, and this combined effect was abolished by PD98059, indicating that ERK was activated by EGF- and cAMP-responsive cascades that converge at MAPK.ConclusioncAMP activates ERK and increases proliferation of ADPKD epithelial cells, but not cells from normal human kidney cortex, through the sequential phosphorylation of PKA, B-Raf and MAPK in a pathway separate from, but complementary to, the classical receptor tyrosine kinase cascade. Consequently, cAMP and EGF have great potential to accelerate the progressive enlargement of renal cysts

Pilot Visual Detection of Small Unmanned Aircraft on Final Approach during Nighttime Conditions

In December 2020, the Federal Aviation Administration (FAA) announced the release of a new final rule, permitting operators of small unmanned aircraft systems (sUAS) to perform routine night operations. Public comments to the Notice of Proposed Rulemaking indicated potential safety concerns regarding a pilot’s ability to spot a low-altitude sUAS during nighttime conditions. Leveraging data from the FAA’s UAS Sighting Report Database, the research team evaluated the significance of aircraft encounters with UAS at night. Researchers conducted an inflight experiment in which 10 pilots performed an instrument approach to airport during nighttime conditions in which a multi-rotor sUAS presented a potential collision hazard. The sUAS was equipped with lighting visible for 3 miles with a sufficient flash rate to avoid a collision, as specified by the new regulation. Participants performed five approaches, with the sUAS flying different scripted encounter profiles. Participants were asked to indicate when they visually spotted the sUAS, with sighting data recorded via an onboard observer. Geolocation information from both the aircraft and sUAS were compared at the time of each reported sighting to assess visibility distance and orientation. The sUAS was successfully spotted during 30 percent (n = 12) of the testing passes. Hovering sUAS were spotted at the same rate as moving sUAS, however, sUAS in motion were spotted at a much greater range. Researchers noted disproportionately higher spotting rates occurred when the sUAS was oriented on the starboard side of the aircraft vs. the port side. It is believed that airport lighting systems may have obscured or otherwise camouflaged portside sUAS encounters. When asked to estimate distance to an encountered sUAS, most participants underestimated, perceiving the sUAS to be much closer than reality. Additionally, the researchers assessed the potential for the participants to initiate evasive maneuvers, based on the distance and closure rate of the aircraft and sUAS at the time of sighting. Based on the FAA’s Aircraft Identification and Reaction Time Chart, collision avoidance would only have been successful during 15 percent of encounters (n = 6). The research team recommends Remote Pilots employ vigilant traffic awareness during nighttime operations, and leverage use of ADS-B (In) technology and monitor Common Traffic Advisory Frequencies to maintain situational awareness—particularly when operating in proximity to airports

Differential effects of Epigallocatechin-3-gallate containing supplements on correcting skeletal defects in a Down syndrome mouse model

SCOPE: Down syndrome (DS), caused by trisomy of human chromosome 21 (Hsa21), is characterized by a spectrum of phenotypes including skeletal abnormalities. The Ts65Dn DS mouse model exhibits similar skeletal phenotypes as humans with DS. DYRK1A, a kinase encoded on Hsa21, has been linked to deficiencies in bone homeostasis in DS mice and individuals with DS. Treatment with Epigallocatechin-3-gallate (EGCG), a known inhibitor of Dyrk1a, improves some skeletal abnormalities associated with DS in mice. EGCG supplements are widely available but the effectiveness of different EGCG-containing supplements has not been well studied. METHODS AND RESULTS: Six commercially available supplements containing EGCG were analyzed, and two of these supplements were compared with pure EGCG for their impact on skeletal deficits in a DS mouse model. The results demonstrate differential effects of commercial supplements on correcting skeletal abnormalities in Ts65Dn mice. Different EGCG-containing supplements display differences in degradation, polyphenol content, and effects on trisomic bone. CONCLUSION: This work suggests that the dose of EGCG and composition of EGCG-containing supplements may be important in correcting skeletal deficits associated with DS. Careful analyses of these parameters may lead to a better understanding of how to improve skeletal and other deficits that impair individuals with DS

Cleared to Land: Pilot Visual Detection of Small Unmanned Aircraft During Final Approach

Sighting reports of unmanned aircraft systems (UAS) by pilots, air traffic controllers, and other aviation stakeholders have continued to rise since the Federal Aviation Administration (FAA) began tracking in 2014. In 2018, the FAA received 2,307 such reports, with 22.8% (n = 526) occurring during the final approach phase of flight. The threat of a midair collision between a manned aircraft and UAS is heightened during the final approach phase of flight, as the aircraft transitions from higher-altitude airspace to the low-altitude arena, now shared with drones. Absent UAS sense and avoid systems, pilots are forced to rely on visual senses and scanning techniques to ensure the approach path remains clear of UAS incursions. This research evaluated the effectiveness of pilot visual detection of a multirotor UAS during five approach to landing scenarios in which an unmanned aircraft created an incursion into the approach path. During the scripted approach scenarios, the UAS either remained stationary or maneuvered laterally. Both aircraft and UAS were separated by established vertical safety margins and protocols to avoid an actual collision. Overall, participants detected the UAS during 30% of the approaches. The static UAS was only detected during 13.6% of the approaches, at a mean range of 647 ft. The detection rate improved to 50% when the drone was in motion, with a mean detection range of 1,593 ft. Vector data was calculated to determine the detection angle of UAS sightings, with the majority of successful detections occurring within 5˚ laterally and 10˚ vertically of center. Qualitative comments were solicited from the participants and evaluated for trends. Forty percent of the participants indicated that moving UAS are easier to spot. Other trends related to UAS contrast, object misidentification, and detection aspect angle were also identified by the participants. The authors emphasized that based on the recorded detection distance, pilots would only have a limited margin of error to successfully execute evasive maneuvers, based on the FAA’s Recommended Minimum Reaction Time Required for Evasion criteria. Full-text will be available October 30, 2019 at approximately 10:00 AM Eastern

Direct Imaging in Reflected Light: Characterization of Older, Temperate Exoplanets With 30-m Telescopes

Direct detection, also known as direct imaging, is a method for discovering and characterizing the atmospheres of planets at intermediate and wide separations. It is the only means of obtaining spectra of non-transiting exoplanets. Characterizing the atmospheres of planets in the <5 AU regime, where RV surveys have revealed an abundance of other worlds, requires a 30-m-class aperture in combination with an advanced adaptive optics system, coronagraph, and suite of spectrometers and imagers - this concept underlies planned instruments for both TMT (the Planetary Systems Imager, or PSI) and the GMT (GMagAO-X). These instruments could provide astrometry, photometry, and spectroscopy of an unprecedented sample of rocky planets, ice giants, and gas giants. For the first time habitable zone exoplanets will become accessible to direct imaging, and these instruments have the potential to detect and characterize the innermost regions of nearby M-dwarf planetary systems in reflected light. High-resolution spectroscopy will not only illuminate the physics and chemistry of exo-atmospheres, but may also probe rocky, temperate worlds for signs of life in the form of atmospheric biomarkers (combinations of water, oxygen and other molecular species). By completing the census of non-transiting worlds at a range of separations from their host stars, these instruments will provide the final pieces to the puzzle of planetary demographics. This whitepaper explores the science goals of direct imaging on 30-m telescopes and the technology development needed to achieve them.Comment: (March 2018) Submitted to the Exoplanet Science Strategy committee of the NA

Identification of a Forskolin-Like Molecule in Human Renal Cysts

Renal cyst enlargement is increased by adenosine cAMP, which is produced within mural epithelial cells. In a search for modulators of cAMP synthesis cyst fluids from 18 patients with autosomal dominant or recessive polycystic kidney disease (PKD) were analyzed, and in 15 of them, a stable lipophilic molecule that increased cAMP levels, stimulated transepithelial chloride and fluid secretion, and promoted the proliferation of human cyst epithelial cells was characterized. With the use of HPLC-mass spectrometry, a bioactive lipid with the same mass spectral fingerprint, the same chromatographic retention time, and the same biologic properties as forskolin, a widely known, potent adenylyl cyclase agonist, has been isolated and identified within the cyst fluid. Forskolin is synthesized by the plant Coleus forskohlii, but its appearance or compounds like it have not been reported in animals. The origin of forskolin in patients with PKD was not revealed by this study. Synthesis by mural cyst epithelial cells or an exogenous source are the most likely possibilities. Forskolin is sold for weight management and as a cardiovascular tonic in health stores and through the Worldwide Web. It is concluded that forskolin may have a role in promoting the enlargement of cysts in autosomal dominant PKD and recommended that patients avoid oral and parenteral preparations that contain this compound

Retrieving the C and O Abundances of HR 7672~AB: a Solar-Type Primary Star with a Benchmark Brown Dwarf

A benchmark brown dwarf (BD) is a BD whose properties (e.g., mass and chemical composition) are precisely and independently measured. Benchmark BDs are valuable in testing theoretical evolutionary tracks, spectral synthesis, and atmospheric retrievals for sub-stellar objects. Here, we report results of atmospheric retrieval on a synthetic spectrum and a benchmark BD -- HR 7672~B -- with \petit. First, we test the retrieval framework on a synthetic PHOENIX BT-Settl spectrum with a solar composition. We show that the retrieved C and O abundances are consistent with solar values, but the retrieved C/O is overestimated by 0.13-0.18, which is $\sim$4 times higher than the formal error bar. Second, we perform retrieval on HR 7672~B using high spectral resolution data (R=35,000) from the Keck Planet Imager and Characterizer (KPIC) and near infrared photometry. We retrieve [C/H], [O/H], and C/O to be $-0.24\pm0.05$, $-0.19\pm0.04$, and $0.52\pm0.02$. These values are consistent with those of HR 7672~A within 1.5-$\sigma$. As such, HR 7672~B is among only a few benchmark BDs (along with Gl 570~D and HD 3651~B) that have been demonstrated to have consistent elemental abundances with their primary stars. Our work provides a practical procedure of testing and performing atmospheric retrieval, and sheds light on potential systematics of future retrievals using high- and low-resolution data.Comment: 29 pages, 17 figures, 5 tables, resubmitted to AAS journals after first revisio