Radio Astronomy

Contains table of contents for Section 4 and reports on nine research projects.National Science Foundation Grant AST 88-19848National Science Foundation Grant AST 90-22501Alfred P. Sloan FellowshipNational Science Foundation Presidential Young Investigator AwardNational Aeronautics and Space Administration Grant NAGW-2310David and Lucile Packard FellowshipSM Systems and Research CorporationNational Aeronautics and Space Administration/Goddard Space Flight Center Contract NAS 5-30791National Aeronautics and Space Administration/Goddard Space Flight Center Grant NAG5-10Leaders for Manufacturing Progra

Radio Astronomy

Contains table of contents and reports on seven research projects.National Science Foundation (Grant AST 86-17172)National Aeronautics and Space AdministrationJet Propulsion LaboratoryNASA/Goddard Space Flight Center (Grant NAG5-10)SM Systems and Research, Inc.U.S. Navy Office of Naval Research (Contract N00014-86-C-2114)Center for Advanced Television StudiesNASA/Goddard Space Flight Center (Grant NAG5-537

Radio Astronomy

Contains table of contents for Section 4 and reports on eight research projects.National Science Foundation Grant AST 88-19848National Aeronautics and Space Administration Goddard Space Flight Center Grant NAGW-2310SM Systems and Research, IncNational Aeronautics and Space Administration Goddard Space Flight Center Grant NAG 5-537National Aeronautics and Space Administration Goddard Space Flight Center Grant NAG 5-10Leaders for Manufacturing ProgramNational Aeronautics and Space Administration Goddard Space Flight Center Grant NAS 5-3079

A targeted decision aid for the elderly to decide whether to undergo colorectal cancer screening: development and results of an uncontrolled trial

Abstract: Background: Competing causes of mortality in the elderly decrease the potential net benefit from colorectal cancer screening and increase the likelihood of potential harms. Individualized decision making has been recommended, so that the elderly can decide whether or not to undergo colorectal cancer (CRC) screening. The objective is to develop and test a decision aid designed to promote individualized colorectal cancer screening decision making for adults age 75 and over. Methods: We used formative research and cognitive testing to develop and refine the decision aid. We then tested the decision aid in an uncontrolled trial. The primary outcome was the proportion of patients who were prepared to make an individualized decision, defined a priori as having adequate knowledge (10/15 questions correct) and clear values (25 or less on values clarity subscale of decisional conflict scale). Secondary outcomes included overall score on the decisional conflict scale, and preferences for undergoing screening. Results: We enrolled 46 adults in the trial. The decision aid increased the proportion of participants with adequate knowledge from 4% to 52% (p < 0.01) and the proportion prepared to make an individualized decision from 4% to 41% (p < 0.01). The proportion that preferred to undergo CRC screening decreased from 67% to 61% (p = 0. 76); 7 participants (15%) changed screening preference (5 against screening, 2 in favor of screening) Conclusion: In an uncontrolled trial, the elderly participants appeared better prepared to make an individualized decision about whether or not to undergo CRC screening after using the decision aid

Radio Astronomy

Contains table of contents for Section 4 and reports on twelve research projects.National Science Foundation Grant AST 88-19848Jet Propulsion Laboratory Contract 957687National Aeronautics and Space Administration Grant NAGW 1386National Science Foundation Grant AST 88-19848Annie Jump Cannon AwardSM Systems and Research, Inc.U.S. Navy Office of Naval Research Contract N00014-88-K-2016NASA/Goddard Space Flight Center Grant NAG 5-537NASA/Goddard Space Flight Center Grant NAG 5-10Woods Hole Oceanographic Institution Contract SC-28860Leaders for Manufacturing Progra

Radio Astronomy

Contains reports on nine research projects.National Science Foundation (Grant AST 86-17172)National Aeronautics and Space Administration (Contract NAS7-918)Jet Propulsion Laboratory (Contract 958048)U.S. Navy - Office of Naval Research (Contract N00014-84-C-2082)U.S. Navy - Office of Naval Research (Contract N00014-86-C-2114)SM Systems and Research, Inc.National Aeronautics and Space Administration/Goddard Space Flight Center (Grant NAG5-10)Center for Advanced Television StudiesBrazil, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (Grant 300.832-82)National Aeronautics and Space Administration/Goddard Space Flight Center (Grant NAG5-537

Site Distribution and Aliasing Effects in the Inversion for Load Coefficients and Geocenter Motion from GPS Data

Precise GPS measurements of elastic relative site displacements due to surface mass loading offer important constraints on global surface mass transport. We investigate effects of site distribution and aliasing by higher-degree (n greater than or equal 2) loading terms on inversion of GPS data for n = 1 load coefficients and geocenter motion. Covariance and simulation analyses are conducted to assess the sensitivity of the inversion to aliasing and mismodeling errors and possible uncertainties in the n = 1 load coefficient determination. We found that the use of center-of-figure approximation in the inverse formulation could cause 10- 15% errors in the inverted load coefficients. n = 1 load estimates may be contaminated significantly by unknown higher-degree terms, depending on the load scenario and the GPS site distribution. The uncertainty in n = 1 zonal load estimate is at the level of 80 - 95% for two load scenarios

Geocenter Motion from a Combination of GRACE Mascon and SLR Data

GRACE and GRACE Follow-On (FO) Level 2 data provide quasi-monthly, band-limited estimates of Stokes (geopotential, spherical harmonic) coefficients mostly reflecting surface mass variability due to non-tidal atmosphere, ocean, and continental hydrology. Although space gravimetry does not directly provide CM-related degree-1 Stokes coefficients, GRACE data have been successfully used over the years to complement time series of station positions from global space-geodetic (SG) network when inverting for Center-of-Mass to Center-of-Network (CM-CN) displacements (Wu et al, 2006). Surficial mass variability observed through GRACE/GRACE-FO can be conveniently converted into load-induced (ENU) deformations at SG observing sites by adopting a spectral (i.e. load Love-number based) formalism and assuming Earth’s response is fully elastic and isotropic. GRACE-derived elastic displacements at observing sites would represent, if accurate, band-limited (degree 2 to 96, or higher if Mascon solutions are adopted) load-induced deformations that can be removed from SG-derived station displacements in order to more accurately recover degree-1 surface deformation signature (and therefore geocenter motion). In this study, we adopt GRACE JPL Mascon RL06 data in conjunction with Preliminary Reference Earth Model-derived load Love numbers to infer elastic displacement at SG sites and remove them from SLR inherently geocentric time series of station positions. In so doing, the residual SLR station displacements, consistently expressed in a geocentric frame, would in principle reflect a degree-1 deformation signature that can be recovered via either surface deformation (Chanard et al, 2018) or translational approach. We will compare the SLR/GRACE (CM-CN) determined in this study to standard estimates of geocenter motion such as ILRS’s and JTRF2014’s estimated via translational approach and spectrally inverted solutions (CM-CF). References Chanard K et al, (2018). JGR-Sol Ea doi:10.1002/2017JB015245 Wu X et al, (2006). JGR-Sol Ea doi:10.1029/2005JB004100