NASA MSFC hardware in the loop simulations of automatic rendezvous and capture systems

Two complementary hardware-in-the-loop simulation facilities for automatic rendezvous and capture systems at MSFC are described. One, the Flight Robotics Laboratory, uses an 8 DOF overhead manipulator with a work volume of 160 by 40 by 23 feet to evaluate automatic rendezvous algorithms and range/rate sensing systems. The other, the Space Station/Station Operations Mechanism Test Bed, uses a 6 DOF hydraulic table to perform docking and berthing dynamics simulations

Understanding how Characteristics of the Nest Site Affect Nest Success of Wild Turkeys

Wild turkeys (Meleagris gallapavo) are a highly-desirable game species throughout the United States, but harvest records in the northern Black Hills, South Dakota suggest that this population is declining.  We wondered whether vegetation characteristics at the nest site would affect nest fate (success/failure).  We monitored 40 nests during summer 2016 to determine nest fate and 27 were successful (?1 egg hatched).  At the actual or expected hatch date, we quantified characteristics of the understory vegetation at the nest bowl, namely total cover, shrub cover, woody debris, and the degree of visual obstruction.  We compared these characteristics between successful and unsuccessful nests. Successful nests had slightly less woody debris and total cover than unsuccessful nests.  We did not detect differences in shrub cover or the degree of visual obstruction.  Our results suggest that there may be some optimal amount of total cover and woody debris at the nest bowl that contributes to a higher chance of nest success.  We recommend additional research that focuses on how vegetation characteristics found at nest sites compares to what is available.  This information in conjunction with our findings could provide guidance for managers regarding vegetation characteristics that may be optimal for nest success.  Although these data may help manage turkey populations, nesting represents only one part of the life cycle of a wild turkey.  We recommend that managers strive for a mosaic of vegetation characteristics to accommodate the needs of turkey populations throughout their life history

Ember Alerts: Assessing Wireless Emergency Alert (WEA) Messages in Wildfires Using the Warning Response Model

When evacuation is necessary in a wildfire event, affected communities must be alerted and warned of the imminent danger and instructed on what to do to protect themselves. One channel available to message providers in the United States is Wireless Emergency Alerts (WEAs) disseminated via IPAWS. Recent wildfire events have shed light on the need to improve WEA strategies and messages when alerting exposed populations of imminent fire threat. The purpose of this article is to assess how, when and where WEAs have been used in US wildfires; whether they comply with guidance set out by Mileti and Sorensen’s Warning Response Model (WRM); and whether the expansion in characters (from 90 to 360) of WEA messages has influenced compliance with the WRM. A quantitative content analysis was conducted of WEA messages sent during US wildfires from January 2020-April 2022. A total of 1,284 messages were manually coded based upon the content and style categories identified in the WRM. Descriptive analyses (and Chi-square tests) were performed to illustrate how 90-character and 360-character WEA messages differ by key content and style features. Results showed that certain content features (i.e., location, guidance, and the name of the hazard) were included more often than others (i.e., source, hazard description, hazard consequences, and timing information) and that the inclusion of most content features increased with increasing message character length. Additionally, when assessing message ‘completeness’, the use of acronyms was prevalent in both 90- and 360-character wildfire WEAs; whereas the inclusion of URLs was linked to increased message length. Wildfire WEAs also displayed inconsistency both within and across states in their use of terminology to trigger evacuation. These findings, among others, have implications for theory highlighting a growing need to confirm that message receivers understand and can act on the messages sent, regardless of the language used. In addition, for message creators, recommendations for effective WEA messages for wildfires are provided

HIV and STI Risk for Young Blacks in High Prevalence Areas: Implications for Health Equity in Communities Hosting Historically Black Colleges and Universities (HBCUs)

Background Every year, thousands of young, black, high school graduates who are seeking higher education, attend one of the 105 historically black colleges and universities (HBCUs) located primarily in the south and east. The objective of the research was to examine the geographic proximity of HBCUs to areas of high HIV and STI disease burden among college age people to assess infectivity of potential sex partners in the areas surrounding HBCUs. Methods We examined the 14 states reporting the greatest HIV diagnoses burden among persons age 20-24 years old and STI burden among persons age 15 to 24 years old available for 2010. The Geographic Information System was used to create a spatially referenced data base of state level HIV and STI disease rates and HBCU zip codes to answer the question “How many HBCUs are in this location?” Maps were created to show HBCU locations in states along with the associated HIV and STI disease burden. Findings Results suggest high HIV and STI disease burden in the general population of persons ages 15-24 in 10 states with 4 or more Historically Black Colleges and Universities (HBCU) and an overall high rate of HIV and STI exposure in the pool of potential sex partners. Less risky behavior by minority young adults attending HBCUs could potentially translate to high risk for contracting the diseases because of high prevalence in surrounding communities. Public Health Message Public health agencies may want to consider prioritizing HBCUs for enhanced HIV and STI prevention collaborative efforts in those areas with a high burden of HIV and other STIs

Inelastic quantum transport: the self-consistent Born approximation and correlated electron-ion dynamics

A dynamical method for inelastic transport simulations in nanostructures is compared with a steady-state method based on non-equilibrium Green's functions. A simplified form of the dynamical method produces, in the steady state in the weak-coupling limit, effective self-energies analogous to those in the Born Approximation due to electron-phonon coupling. The two methods are then compared numerically on a resonant system consisting of a linear trimer weakly embedded between metal electrodes. This system exhibits enhanced heating at high biases and long phonon equilibration times. Despite the differences in their formulation, the static and dynamical methods capture local current-induced heating and inelastic corrections to the current with good agreement over a wide range of conditions, except in the limit of very high vibrational excitations, where differences begin to emerge.Comment: 12 pages, 7 figure

What makes for prize-winning television?

We investigate the determinants of success in four international television awards festivals between 1994 and 2012. We find that countries with larger markets and greater expenditure on public broadcasting tend to win more awards, but that the degree of concentration in the market for television and rates of penetration of pay-per-view television are unrelated to success. These findings are consistent with general industrial organisation literature on quality and market size, and with media policy literature on public service broadcasting acting as a force for quality. However, we also find that ‘home countries’ enjoy a strong advantage in these festivals, which is not consistent with festival success acting as a pure proxy for television quality

Repetitive task training for improving functional ability after stroke

<p><b>Objectives:</b> The objective of this review was to determine if repetitive task training after stroke improves global, upper, or lower limb function and if treatment effects are influenced by the amount, type, or timing of practice.</p> <p><b>Search Strategy:</b> We searched the Cochrane Stroke Trials Register (to October 2006); The Cochrane Library, MEDLINE, EMBASE, CINAHL, AMED, SportDiscus, Science Citation Index, Index to Theses, ZETOC, PEDro, and OT Seeker (all to September 2006); and OT search (to March 2006). We also searched for unpublished/non-English language trials; combed conference proceedings and reference lists; requested information on bulletin boards; and contacted trial authors.</p> <p><b>Selection Criteria:</b> Selection criteria included randomized/quasirandomized trials in adults after stroke, of interventions that included an active motor sequence performed repetitively within a single training session, a clear functional goal, and a quantifiable level of practice.</p> <p><b>Data Collection and Analysis:</b> Two authors independently screened abstracts, extracted data, and appraised trial quality. Further information was obtained from study authors. Results from individual trials were combined using meta-analytic techniques appropriate to the data extracted and the level of between-trial heterogeneity.</p> <p><b>Main Results:</b> Fourteen trials with 17 intervention-control pairs and 659 participants were included. Primary outcomes showed that treatment effects were statistically significant for walking distance (see the Figure); walking speed (standardized mean difference, 0.29; 95% CI, 0.04 to 0.53); and sit-to-stand (standardized effect estimate, 0.35; 95% CI, 0.13 to 0.56). Treatment effects were of borderline statistical significance for functional ambulation.</p&gt

Pion Content of the Nucleon as seen in the NA51 Drell-Yan experiment

In a recent CERN Drell-Yan experiment the NA51 group found a strong asymmetry of $\bar u$ and $\bar d$ densities in the proton at $x\simeq0.18$. We interpret this result as a decisive confirmation of the pion-induced sea in the nucleon.Comment: 10 pages + 3 figures, Preprint KFA-IKP(TH)-1994-14 .tex file. After \enddocument a uu-encodeded Postscript file comprising the figures is appende

LD4PE: A Competency-based Guide to Linked Data Principles and Practices

The IMLS-funded Linked Data for Professional Education (LD4PE) project has developed a competency-based prototype referatory of Learning Resources for teaching and learning practices in the design, implementation, and management of Linked Data. This report summarizes the work of the project in developing: 1) an RDF-modeled “Competency Index for Linked Data” (Index) based on the Achievements Standards Network Description Language (ASN-DL) for describing formally promulgated competencies and benchmarks; 2) an openly available, web-based tool set to support the management of the Index; the generation of RDF metadata about Learning Resources; the packaging and arrangement of selected Learning Resources by users in “Saved Sets”; and the creation of learning trajectory maps expressing curricular structures or personal learning journeys superimposed over the competency framework through the integration of these elements as WordPress custom posts and taxonomies on the LD4PE website; 3) a set of cataloged Learning Resources that have been mapped to the competencies and benchmarks of the Index to support competency-based resource discovery by teachers, trainers and learners; 4) the LD4PE project website (http://explore.dublincore.net), which will be managed by the Dublin Core Metadata Initiative (DCMI) as part of its educational agenda; and 5) a set of Best Practices describing the infrastructure and policies developed for the project that others can reuse in mapping future knowledge domains in a similar manner

A systematic review of repetitive task training with modelling of resource use, costs and effectiveness

OBJECTIVES: To determine whether repetitive functional task practice (RFTP) after stroke improves limb-specific or global function or activities of daily living and whether treatment effects are dependent on the amount of practice, or the type or timing of the intervention. Also to provide estimates of the cost-effectiveness of RFTP. DATA SOURCES: The main electronic databases were searched from inception to week 4, September 2006. Searches were also carried out on non-English-language databases and for unpublished trials up to May 2006. REVIEW METHODS: Standard quantitative methods were used to conduct the systematic review. The measures of efficacy of RFTP from the data synthesis were used to inform an economic model. The model used a pre-existing data set and tested the potential impact of RFTP on cost. An incremental cost per quality-adjusted life-year (QALY) gained for RFTP was estimated from the model. Sensitivity analyses around the assumptions made for the model were used to test the robustness of the estimates. RESULTS: Thirty-one trials with 34 intervention-control pairs and 1078 participants were included. Overall, it was found that some forms of RFTP resulted in improvement in global function, and in both arm and lower limb function. Overall standardised mean difference in data suitable for pooling was 0.38 [95% confidence interval (CI) 0.09 to 0.68] for global motor function, 0.24 (95% CI 0.06 to 0.42) for arm function and 0.28 (95% CI 0.05 to 0.51) for functional ambulation. Results suggest that training may be sufficient to have an impact on activities of daily living. Retention effects of training persist for up to 6 months, but whether they persist beyond this is unclear. There was little or no evidence that treatment effects overall were modified by time since stroke or dosage of task practice, but results for upper limb function were modified by type of intervention. The economic modelling suggested that RFTP was cost-effective. Given a threshold for cost-effectiveness of 20,000 pounds per QALY gained, RFTP is cost-effective so long as the net cost per patient is less than 1963 pounds. This result showed some sensitivity to the assumptions made for the model. The cost-effectiveness of RFTP tends to stem from the relatively modest cost associated with this intervention. CONCLUSIONS: The evidence suggests that some form of RFTP can be effective in improving lower limb function at any time after stroke, but that the duration of intervention effect is unclear. There is as yet insufficient good-quality evidence to make any firm recommendations for upper limb interventions. If task-specific training is used, adverse effects should be monitored. While the effectiveness of RFTP is relatively modest, this sort of intervention appears to be cost-effective. Owing to the large number of ongoing trials, this review should be updated within 2 years and any future review should include a comparison against alternative treatments. Further research should evaluate RFTP upper limb interventions and in particular constraint-induced movement therapy, address practical ways of delivering RFTP interventions, be directed towards the evaluation of suitable methods to maintain functional gain, and be powered to detect whether RFTP interventions are cost-effective