17 research outputs found

    Near Earth Asteroid Scout - Mission Update

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    After its deployment from NASA’s Space Launch System (SLS), the Near-Earth Asteroid (NEA) Scout mission will travel to and image an asteroid during a close flyby using an 86m2 solar sail as its primary propulsion. Solar sails are large, mirror-like structures made of a lightweight material that reflects sunlight to propel the spacecraft. The continuous solar photon pressure provides thrust with no need for the heavy, expendable propellants used by conventional chemical and electric propulsion systems. Developed by NASA’s Marshall Space Flight Center (MSFC) and Jet Propulsion Laboratory (JPL), the NEA Scout is based on the industry-standard CubeSat form factor. The spacecraft measures 11 cm x 24 cm x 36 cm and weighs less than 14 kilograms. Following deployment from the Space Launch System (SLS), the solar sail will deploy, and the spacecraft will begin its 2.0 – 2.5-year journey. About one month before the asteroid flyby, NEA Scout will search for the target and start its Approach Phase using a combination of radio tracking and optical navigation and perform a relatively slow flyby (10-20 m/s) of the target. A summary of the mission, sailcraft, mission design, and its first several months of deep space operation will be described

    Footprint evidence of early hominin locomotor diversity at Laetoli, Tanzania

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    Bipedal trackways discovered in 1978 at Laetoli site G, Tanzania and dated to 3.66 million years ago are widely accepted as the oldest unequivocal evidence of obligate bipedalism in the human lineage1-3. Another trackway discovered two years earlier at nearby site A was partially excavated and attributed to a hominin, but curious affinities with bears (ursids) marginalized its importance to the paleoanthropological community, and the location of these footprints fell into obscurity3-5. In 2019, we located, excavated and cleaned the site A trackway, producing a digital archive using 3D photogrammetry and laser scanning. Here we compare the footprints at this site with those of American black bears, chimpanzees and humans, and we show that they resemble those of hominins more than ursids. In fact, the narrow step width corroborates the original interpretation of a small, cross-stepping bipedal hominin. However, the inferred foot proportions, gait parameters and 3D morphologies of footprints at site A are readily distinguished from those at site G, indicating that a minimum of two hominin taxa with different feet and gaits coexisted at Laetoli

    Isolation and Characterization of Microsatellite Loci from Amur Honeysuckle, <i>Lonicera maackii</i> (Caprifoliaceae)

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    Premise of the study: Lonicera maackii (Caprifoliaceae) is one of the most problematic invasive shrubs in forests of the eastern United States. Microsatellite markers could serve to test putative source-sink relationships among populations to determine whether invasions progress along expanding fronts or through long-distance dispersal events followed by local expansion. Methods and Results: Eleven microsatellite loci were developed for Amur honeysuckle using a modified magnetic bead protocol. Six loci were screened across 158 individuals from seven populations and were shown to be variable, with the number of alleles per locus ranging from seven to 16. Observed heterozygosity ranged from 0.655 to 0.757. Five additional loci were screened using 68 individuals from three different populations, with seven to 12 alleles per locus and observed heterozygosity ranging from 0.682 and 0.831. Conclusions: These microsatellite markers will help to elucidate the genetic structure and patterns of dispersal of L. maackii in its invasive range

    Racial Disparity in Hypertensive Disorders of Pregnancy in New York State: A 10-Year Longitudinal Population-Based Study

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    Objectives. We studied trends of hypertensive disorders of pregnancy by residential socioeconomic status (SES) and racial/ethnic subgroups in New York State over a 10-year period. Methods. We merged New York State discharge data for 2.5 million women hospitalized with delivery from 1993 through 2002 with 2000 US Census data. Results. Rates of diagnoses for all hypertensive disorders combined and for preeclampsia individually were highest among Black women across all regions and neighborhood poverty levels. Although hospitalization rates for preeclampsia decreased over time for most groups, differences in rates between White and Black women increased over the 10-year period. The proportion of women living in poor areas remained relatively constant over the same period. Black and Hispanic women were more likely than White women to have a form of diabetes and were at higher risk of preeclampsia; preeclampsia rates were higher in these groups both with and without diabetes than in corresponding groups of White women. Conclusions. An increasing trend of racial/ethnic disparity in maternal hypertension rates occurred in New York State during the past decade. This trend was persistent after stratification according to SES and other risk factors. Additional research is needed to understand the factors contributing to this growing disparity
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