OSSOS. IV. DISCOVERY OF A DWARF PLANET CANDIDATE IN THE 9 : 2 RESONANCE WITH NEPTUNE

We report the discovery and orbit of a new dwarf planet candidate, 2015 RR245, by the Outer Solar System Origins Survey (OSSOS). The orbit of 2015 RR245 is eccentric (e = 0.586), with a semimajor axis near 82 au, yielding a perihelion distance of 34 au. 2015 RR245 has g - r = 0.59 +/- 0.11 and absolute magnitude H-r = 3.6 +/- 0.1; for an assumed albedo of p(V) = 12%, the object has a diameter of similar to 670. km. Based on astrometric measurements from OSSOS and Pan-STARRS1, we find that 2015 RR245 is securely trapped on ten-megayear timescales in the 9: 2 mean-motion resonance with Neptune. It is the first trans-Neptunian object (TNO) identified in this resonance. On hundred-megayear. timescales, particles in 2015 RR245-like orbits depart and sometimes return to the resonance, indicating that 2015 RR245 likely forms part of the long-lived metastable population of distant TNOs that drift between resonance sticking and actively scattering via gravitational encounters with Neptune. The discovery of a 9: 2 TNO stresses the role of resonances in the long-term evolution of objects in the scattering disk. and reinforces the view that distant resonances are heavily populated in the current solar system. This object further motivates detailed modeling of the transient sticking population.Peer reviewe

OSSOS. VII. 800+Trans-Neptunian Objects-The Complete Data Release

The Outer Solar System Origins Survey (OSSOS), a wide-field imaging program in 2013-2017 with the Canada-France-Hawaii Telescope, surveyed 155 deg(2) of sky to depths of m(r) = 24.1-25.2. We present 838 outer solar system discoveries that are entirely free of ephemeris bias. This increases the inventory of trans-Neptunian objects (TNOs) with accurately known orbits by nearly 50%. Each minor planet has 20-60 Gaia/Pan-STARRS-calibrated astrometric measurements made over 2-5 oppositions, which allows accurate classification of their orbits within the trans-Neptunian dynamical populations. The populations orbiting in mean-motion resonance with Neptune are key to understanding Neptune's early migration. Our 313 resonant TNOs, including 132 plutinos, triple the available characterized sample and include new occupancy of distant resonances out to semimajor axis a similar to 130 au. OSSOS doubles the known population of the nonresonant Kuiper Belt, providing 436 TNOs in this region, all with exceptionally high-quality orbits of a uncertainty sigma(a)Peer reviewe

The Outer Solar System Origins Survey : I. Design and First-Quarter Discoveries

We report the discovery, tracking, and detection circumstances for 85 trans-Neptunian objects (TNOs) from the first 42 deg(2) of the Outer Solar System Origins Survey. This ongoing r-band solar system survey uses the 0.9 deg(2) field of view MegaPrime camera on the 3.6m Canada-France-Hawaii Telescope. Our orbital elements for these TNOs are precise to a fractional semimajor axis uncertaintyPeer reviewe

Perception of Medical Student Mistreatment: Does Specialty Matter?

Purpose Medical student mistreatment is pervasive, yet whether all physicians have a shared understanding of the problem is unclear. The authors presented professionally designed trigger videos to physicians from 6 different specialties to determine if they perceive mistreatment and its severity similarly. Method From October 2016 to August 2018, resident and attending physicians from 10 U.S. medical schools viewed 5 trigger videos showing behaviors that could be perceived as mistreatment. They completed a survey exploring their perceptions. The authors compared perceptions of mistreatment across specialties and, for each scenario, evaluated the relationship between specialty and perception of mistreatment. Results Six-hundred fifty resident and attending physicians participated. There were statistically significant differences in perception of mistreatment across specialties for 3 of the 5 scenarios: aggressive questioning (range, 74.1%–91.2%), negative feedback (range, 25.4%–63.7%), and assignment of inappropriate tasks (range, 5.5%–25.5%) (P ≤ .001, for all). After adjusting for gender, race, professional role, and prior mistreatment, physicians in surgery viewed 3 scenarios (aggressive questioning, negative feedback, and inappropriate tasks) as less likely to represent mistreatment compared with internal medicine physicians. Physicians from obstetrics–gynecology and “other” specialties perceived less mistreatment in 2 scenarios (aggressive questioning and negative feedback), while family physicians perceived more mistreatment in 1 scenario (negative feedback) compared with internal medicine physicians. The mean severity of perceived mistreatment on a 1 to 7 scale (7 most serious) also varied statistically significantly across the specialties for 3 scenarios: aggressive questioning (range, 4.4–5.4; P < .001), ethnic insensitivity (range, 5.1–6.1; P = .001), and sexual harassment (range, 5.5–6.3; P = .004). Conclusions Specialty was associated with differences in the perception of mistreatment and rating of its severity. Further investigation is needed to understand why these perceptions of mistreatment vary among specialties and how to address these differences.12 month embargo; published online: 29 June 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

A new high-perihelion a ~ 700 AU object in the distant Solar System

International audienceWe report the discovery of a trans-Neptunian object (TNO) plausibly diffusing out of the inner Oort Cloud reservoir. This TNO is on an orbit with q ~ 50 AU, a ~ 700 AU, the largest semi-major axis yet detected for an orbit with perihelion q beyond the q ≤ 38 zone of strong influence of Neptune, exceeding the semi-major axes of (90377) Sedna, 2012 VP113 and 2010 GB174. Such objects are rarely observed. Trans-Neptunian objects with these high orbital perihelia have no confirmed formation mechanism in the present planetary architecture of the Solar System. The orbit of this new TNO can be formed by inward diffusion of objects from a Galactic-tide-dominated population with a ~ 1000-2000 AU; the formation mechanism is highly inefficient, and would require on the order of a hundred times more objects in that population than in the a ~ 700 AU population. We also report colour and light curve measurements of the new TNO with Gemini North and Subaru-HSC. The longitude of the ascending node and argument of perihelion of this TNO's orbit have implications for the hypothesis of a ninth planet

A new high-perihelion a ~ 700 AU object in the distant Solar System

International audienceWe report the discovery of a trans-Neptunian object (TNO) plausibly diffusing out of the inner Oort Cloud reservoir. This TNO is on an orbit with q ~ 50 AU, a ~ 700 AU, the largest semi-major axis yet detected for an orbit with perihelion q beyond the q ≤ 38 zone of strong influence of Neptune, exceeding the semi-major axes of (90377) Sedna, 2012 VP113 and 2010 GB174. Such objects are rarely observed. Trans-Neptunian objects with these high orbital perihelia have no confirmed formation mechanism in the present planetary architecture of the Solar System. The orbit of this new TNO can be formed by inward diffusion of objects from a Galactic-tide-dominated population with a ~ 1000-2000 AU; the formation mechanism is highly inefficient, and would require on the order of a hundred times more objects in that population than in the a ~ 700 AU population. We also report colour and light curve measurements of the new TNO with Gemini North and Subaru-HSC. The longitude of the ascending node and argument of perihelion of this TNO's orbit have implications for the hypothesis of a ninth planet

Association between GAB2 haplotype and higher glucose metabolism in Alzheimer's disease-affected brain regions in cognitively normal APOE[epsilon]4 carriers

In a genome-wide association study (GWAS) of late-onset Alzheimer's disease (AD), we found an association between common haplotypes of the GAB2 gene and AD risk in carriers of the apolipoprotein E (APOE) [straight epsilon]4 allele, the major late-onset AD susceptibility gene. We previously proposed the use of fluorodeoxyglucose positron emission tomography (FDG-PET) measurements as a quantitative pre-symptomatic endophenotype, more closely related to disease risk than the clinical syndrome itself, to help evaluate putative genetic and non-genetic modifiers of AD risk. In this study, we examined the relationship between the presence or absence of the relatively protective GAB2 haplotype and PET measurements of regional-to-whole brain FDG uptake in several AD-affected brain regions in 158 cognitively normal late-middle-aged APOE[straight epsilon]4 homozygotes, heterozygotes, and non-carriers. GAB2 haplotypes were characterized using Affymetrix Genome-Wide Human SNP 6.0 Array data from each of these subjects. As predicted, the possibly protective GAB2 haplotype was associated with higher regional-to-whole brain FDG uptake in AD-affected brain regions in APOE[straight epsilon]4 carriers. While additional studies are needed, this study supports the association between the possibly protective GAB2 haplotype and the risk of late-onset AD in APOE[straight epsilon]4 carriers. It also supports the use of brain-imaging endophenotypes to help assess possible modifiers of AD risk