1,479 research outputs found
Comparison of circular orbit and Fourier power series ephemeris representations for backup use by the upper atmosphere research satellite onboard computer
The Upper Atmosphere Research Satellite (UARS) is a three-axis stabilized Earth-pointing spacecraft in a low-Earth orbit. The UARS onboard computer (OBC) uses a Fourier Power Series (FPS) ephemeris representation that includes 42 position and 42 velocity coefficients per axis, with position residuals at 10-minute intervals. New coefficients and 32 hours of residuals are uploaded daily. This study evaluated two backup methods that permit the OBC to compute an approximate spacecraft ephemeris in the event that new ephemeris data cannot be uplinked for several days: (1) extending the use of the FPS coefficients previously uplinked, and (2) switching to a simple circular orbit approximation designed and tested (but not implemented) for LANDSAT-D. The FPS method provides greater accuracy during the backup period and does not require additional ground operational procedures for generating and uplinking an additional ephemeris table. The tradeoff is that the high accuracy of the FPS will be degraded slightly by adopting the longer fit period necessary to obtain backup accuracy for an extended period of time. The results for UARS show that extended use of the FPS is superior to the circular orbit approximation for short-term ephemeris backup
A study of the impact of the Ceramic Materials Research program at the University of Washington Final report, 15 Jun. 1968 - 15 Sep. 1969
Impact of Ceramic Materials Research Program at University of Washingto
IRSp53 coordinates AMPK and 14-3-3 signaling to regulate filopodia dynamics and directed cell migration
The RootScope: A Simple High-Throughput Screening System For Quantitating Gene Expression Dynamics In Plant Roots
Background: High temperature stress responses are vital for plant survival. The mechanisms that plants use to sense high temperatures are only partially understood and involve multiple sensing and signaling pathways. Here we describe the development of the RootScope, an automated microscopy system for quantitating heat shock responses in plant roots.Results: The promoter of Hsp17.6 was used to build a Hsp17.6(p):GFP transcriptional reporter that is induced by heat shock in Arabidopsis. An automated fluorescence microscopy system which enables multiple roots to be imaged in rapid succession was used to quantitate Hsp17.6p: GFP response dynamics. Hsp17.6(p):GFP signal increased with temperature increases from 28 degrees C to 37 degrees C. At 40 degrees C the kinetics and localization of the response are markedly different from those at 37 degrees C. This suggests that different mechanisms mediate heat shock responses above and below 37 degrees C. Finally, we demonstrate that Hsp17.6(p):GFP expression exhibits wave like dynamics in growing roots.Conclusions: The RootScope system is a simple and powerful platform for investigating the heat shock response in plants
\u3cem\u3eHSFA1d\u3c/em\u3e Regulates The Kinetics Of Heat-Induced \u3cem\u3eHSP17.6\u3c/em\u3e Expression In Arabidopsis
Arabidopsis contains four HSFA1 heat shock transcription factors (HSFA1a, HSFA1b, HSFA1d, and HSFA1e) that regulate the primary response to high temperature stress responses. These genes have overlapping functions and, while double and triple HSFA1 mutants have thermotolerance phenotypes, these genes have no reported single mutant thermotolerance phenotypes. We used an automated fluorescence microscopy system to quantitate the expression of a HSP17.6:GFP reporter with high temporal resolution to show that HSFA1d is required for normal heat-induced HSP17.6 expression. HSP17.6 expression is reduced and delayed in hsfa1d-1 mutants. This finding highlights the power of using gene expression kinetics as a quantitative phenotype for discovering the function of genes that exhibit functional redundancy
Quality of Life on the Agricultural Treadmill: Individual and Community Determinants of Farm Family Well-Being
Individual quality of life (QOL) is a critical foundation of stable and cohesive societies. This research examines QOL among Iowa farmers, who as a group have seen their numbers decline precipitously over the past decades as the farm economy has undergone major restructuring processes. Farm families are nested in rural communities, many of which have also experienced persistent population loss and economic decline over the same period. A multilevel modeling approach is employed to examine determinants of subjective QOL over time, using 29 years of longitudinal data. Results point to positive relationships between household income, community vitality, and farm family QOL. Individual stress and economic dependence on farming were negatively associated with QOL. The finding that community vitality is a critical determinant of farm family quality of life supports long-standing appeals to increase investment in community development efforts
An Unsteady Entropy Adjoint Approach for Adaptive Solution of the Shallow-Water Equations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90693/1/AIAA-2011-3694-887.pd
Computer processing support, volume 4
There are no author-identified significant results in this report
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