Interferometric tracking system for the tracking and data relay satellite

This report documents construction and testing of the Interferometric Tracking System project developed under the NASA SBIR contract NAS5-30313. Manuals describing the software and hardware, respectively entitled: 'Field Station Guide to Operations' and 'Field Station Hardware Manual' are included as part of this final report. The objective of this contract was to design, build, and operate a system of three ground stations using Very Long Baseline Interferometry techniques to measure the TDRS orbit. The ground stations receive signals from normal satellite traffic, store these signals in co-located computers, and transmit the information via phone lines to a central processing site which correlates the signals to determine relative time delays. Measurements from another satellite besides TDRS are used to determine clock offsets. A series of such measurements will ultimately be employed to derive the orbital parameters, yielding positions accurate to within 50 meters or possibly better

Connecting the Dots: Stages of Implementation, Wraparound Fidelity and Youth Outcomes

Several necessary system and organizational support conditions for wraparound have been identified (Walker et al. 2003). Yet, the relationship between these necessary system level conditions and wraparound fidelity has only recently begun to be examined. Similarly, few studies have included a measure of wraparound fidelity when examining the relationship between wraparound implementation and youth outcomes. The statewide implementation of a wraparound demonstration grant offers the opportunity to explore these relationships and to identify factors that predict improvement in functioning for youth receiving wraparound. Findings suggest that significant relationships exist between (1) the stage of development of necessary support conditions for wraparound and wraparound fidelity and (2) wraparound fidelity and improvement in youth outcomes. Specific elements of wraparound (i.e., outcomes based and community based) and baseline needs and strengths (e.g., high levels of anxiety and conduct issues, poor functioning at home and in school, judgment, and risks) were found to predict a reduction in youth needs. Other unexpected relationships between youth outcomes and the cultural competence element of wraparound and being multi-racial were also discovered. These findings reinforce the importance of supporting high fidelity wraparound for youth and their families in a recovery focused behavioral health system

Accounting for photodegradation dramatically improves prediction of carbon losses in dryland systems

Traditional models of decomposition fail to capture litter mass loss patterns in dryland systems. This shortcoming has stimulated research into alternative drivers of decomposition, including photodegradation. Here, we use aboveground litter decomposition data for dryland (arid) sites from the Long-term Intersite Decomposition Experiment Team data set to test hypotheses (models) about the mechanisms and impacts of photodegradation. Incorporating photodegradation into a traditional biotic decomposition model substantially improved model predictions for mass loss at these dryland sites, especially after four years. The best model accounted for the effects of solar radiation via photodegradation loss from the intermediate cellulosic and lignin pools and direct inhibition of microbial decomposition. Despite the concurrent impacts of photodegradation and inhibition on mass loss, the best photodegradation model increased mass loss by an average of 12% per year compared to the biotic-only decomposition model. The best model also allowed soil infiltration into litterbags to reduce photodegradation and inhibition of microbial decomposition by shading litter from solar radiation. Our modeling results did not entirely support the popular hypothesis that initial lignin content increases the effects of photodegradation on litter mass loss; surprisingly, higher initial lignin content decreased the rate of cellulosic photodegradation. Importantly, our results suggest that mass loss rates due to photodegradation may be comparable to biotic decomposition rates: Mass loss due to photodegradation alone resulted in litter mass losses of 6–15% per year, while mass loss due to biotic decomposition ranged from 20% per year during early-stage decomposition to 3% per year during late-stage decomposition. Overall, failing to account for the impacts of solar radiation on litter mass loss under-predicted long-term litter mass loss by approximately 26%. Thus, not including photodegradation in dryland decomposition models likely results in large underestimations of carbon loss from dryland systems

Comprehensive genetic dissection of wood properties in a widely-grown tropical tree: Eucalyptus

Background: Eucalyptus is an important genus in industrial plantations throughout the world and is grown for use as timber, pulp, paper and charcoal. Several breeding programmes have been launched worldwide to concomitantly improve growth performance and wood properties (WPs). In this study, an interspecific cross between Eucalyptus urophylla and E. grandis was used to identify major genomic regions (Quantitative Trait Loci, QTL) controlling the variability of WPs. Results: Linkage maps were generated for both parent species. A total of 117 QTLs were detected for a series of wood and end-use related traits, including chemical, technological, physical, mechanical and anatomical properties. The QTLs were mainly clustered into five linkage groups. In terms of distribution of QTL effects, our result agrees with the typical L-shape reported in most QTL studies, i.e. most WP QTLs had limited effects and only a few (13) had major effects (phenotypic variance explained > 15%). The co-locations of QTLs for different WPs as well as QTLs and candidate genes are discussed in terms of phenotypic correlations between traits, and of the function of the candidate genes. The major wood property QTL harbours a gene encoding a Cinnamoyl CoA reductase (CCR), a structural enzyme of the monolignol-specific biosynthesis pathway. Conclusions: Given the number of traits analysed, this study provides a comprehensive understanding of the genetic architecture of wood properties in this Eucalyptus full-sib pedigree. At the dawn of Eucalyptus genome sequence, it will provide a framework to identify the nature of genes underlying these important quantitative traits. (Résumé d'auteur

Formal assessment of the AN/EX structural engineering teaching laboratory

A newly developed portable, computer‐assisted, structural engineering teaching laboratory, called AN/EX, has been incorporated into the civil engineering curriculum at the University of Missouri‐Rolla (UMR). A formal assessment of AN/EX was conducted to identify its effect on the abilities and attitudes of UMR civil engineering students. The assessment methodology is described. Opinion surveys indicated that AN/EX had a positive influence on student attitudes. Statistical analyses of test scores indicated that AN/EX did not undermine traditional problem solving skills, but it did have a positive influence on student abilities to solve synthesis‐oriented structural engineering problems. Copyright © 1994 John Wiley & Sons, Inc