19 research outputs found

    Barriers to and Facilitators of COVID-19 Prevention Behaviors Among North Carolina Residents

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    COVID-19 was the third leading cause of death in the United States in 2020. Prior to the wide dissemination of SARS-CoV-2 vaccines, individual prevention behaviors, such as wearing face masks, have been the primary non-pharmaceutical interventions to reduce infections. We surveyed 404 North Carolina residents recruited through Amazon MTurk in July 2020 to assess adherence to key prevention behaviors (6-foot distancing, mask wearing, and gathering limits) and barriers to and facilitators of adherence. Participants reported past 7-day prevention behaviors and behavioral barriers and facilitators informed by the Integrated Behavior Model and the Health Belief Model (perceived risk, perceived severity, behavioral attitudes, injunctive and descriptive norms, and personal agency). Reported adherence to each behavior in the past 7 days was generally high, with lower adherence to 6-foot distancing and mask wearing in the work context. The most commonly endorsed barriers to 6-foot distancing included physical impediments, forgetting, and unfavorable descriptive norms. For mask wearing, ability to keep a distance, discomfort/inconvenience, and forgetting were most commonly endorsed. In logistic regression models, injunctive social norms followed by perceived personal agency were the strongest independent correlates of 6-foot distancing. Behavioral attitudes and injunctive social norms were independently associated with mask wearing. For gathering size limit adherence, perceived personal agency was the strongest independent predictor followed by perceived severity of COVID-19. Messaging campaigns targeting these barriers and facilitators should be tested. Interventions improving the convenience and salience of physical distancing and mask wearing in high-density public places and places of work may also promote prevention behaviors

    Precise Masses for Wolf 1062 AB from Hubble Space Telescope Interferometric Astrometry and McDonald Observatory Radial Velocities

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    We present an analysis of astrometric data from FGS 3, a white-light interferometer on {\it HST}, and of radial velocity data from two ground-based campaigns. We model the astrometric and radial velocity measurements simultaneously to obtain parallax, proper motion and component masses for Wolf 1062 = Gl 748 AB (M3.5V). To derive the mass fraction, we relate FGS 3 fringe scanning observations of the science target to a reference frame provided by fringe tracking observations of a surrounding star field. We obtain an absolute parallax πabs=98.0±0.4\pi_{abs} = 98.0 \pm 0.4 milliseconds of arc, yielding {\cal M}_A = 0.379 \pm 0.005{\cal M}_{\sun} and {\cal M}_B= 0.192 \pm 0.003 {\cal M}_{\sun}, high quality component masses with errors of only 1.5%.Comment: 13 pages, 7 figures. To appear in AJ March 200

    The Distance to the Hyades Cluster Based on HST Fine Guidance Sensor Parallaxes

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    Trigonometric parallax observations made with the Hubble Space Telescope's Fine Guidance Sensor #3 (HST FGS) of seven Hyades Cluster members in six fields of view have been analyzed along with their proper motions to determine the distance to the cluster. Knowledge of the Cluster's convergent point and mean proper motion are critical to the derivation of the distance to the center of the cluster. Depending on the choice of the proper-motion system, the derived cluster center distance varies by 9%. Adopting a reference distance of 46.1 pc or m-M=3.32, which is derived from the ground-based parallaxes in the General Catalogue of Trigonometric Stellar Parallaxes (1995 edition), the FK5/PPM proper-motion system yields a distance 4% larger, while the Hanson (1975) system yields a distance 2% smaller. The HST FGS parallaxes reported here yield either a 14% or 5% larger distance depending on the choice of the proper-motion system. Orbital parallaxes (Torres et al. 1997a, 1997b, 1997c) yield an average distance 4% larger than the reference distance. The variation in the distance derived from the HST data illustrates the importance of the proper-motion system and the individual proper motions to the derivation of the distance to the Hyades Cluster center, therefore a full utilization of the HST FGS parallaxes awaits the establishment of an accurate and consistent proper-motion system.Comment: 7 pages; This study is collaborated with 8 institution

    Spatial variation of fundamental couplings and Lunar Laser Ranging

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    If the fundamental constants of nature have a cosmic spatial variation, there will in general be extra forces with a preferred direction in space which violate the equivalence principle. We show that the millimeter-precision Apache Point Observatory Lunar Laser-ranging Operation provides a very sensitive probe of such variation that has the capability of detecting a cosmic gradient of the ratio between the quark masses and the strong interaction scale at the level ∇ ln(mquark/ΛQCD) ∼ 2.6 × 10−6 Glyr−1, which is comparable to the cosmic gradients suggested by the recently reported measurements of Webb et al. We also point out the capability of presently planned improved equivalence principle tests, at the ∆g/g . 10−17 level, to probe similar cosmic gradients
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