Some recent results in aerospace vehicle trajectory optimization techniques

Algorithms and computation techniques for solving trajectory optimization problem

The Infrared Imaging Spectrograph (IRIS) for TMT: the atmospheric dispersion corrector

We present a conceptual design for the atmospheric dispersion corrector (ADC) for TMT's Infrared Imaging Spectrograph (IRIS). The severe requirements of this ADC are reviewed, as are limitations to observing caused by uncorrectable atmospheric effects. The requirement of residual dispersion less than 1 milliarcsecond can be met with certain glass combinations. The design decisions are discussed and the performance of the design ADC is described. Alternative options and their performance tradeoffs are also presented.Comment: SPIE Astronomical Instrumentation 201

Who Do We Reach? Campaign Evaluation of Find Thirty every day® Using Awareness Profiles in a Western Australian Cohort

Mass media campaigns are part of a comprehensive, population-based approach to communicate physical activity behavior change. Campaign awareness is the most frequently reported, short-term comparable measure of campaign effectiveness. Most mass media campaigns report those who were aware with those who are unaware of campaigns. Few campaigns follow awareness in the same respondent, over time, during a mass media campaign to track different patterns of awareness or awareness profiles—“never,” “early,” “late,” or “always”—that may emerge. Using awareness profiles, the authors (a) address any demographic differences between groups and (b) assess changes in physical activity. Find Thirty every day® was a populationwide mass media campaign delivered in Western Australia. The cohort comprised 405 participants, who completed periodic telephone interviews over 2 years. Almost one third (30.4%) were “never aware” of the campaign. More than one third recalled the campaign at one or more time points—“early aware.” Ten percent became aware at Time 2 and stayed aware of the campaign across the remaining time. Examining within and across the awareness profiles, only gender was significant. This article provides an approach to profiling awareness, whereby people cycle in and out and few people are “always aware” over a 2-year period. It presents possible implications and considerations for future campaign planners interested in establishing and maintaining campaign awareness with adult populations

Changes in Australian community perceptions of non-communicable disease prevention: a greater role for government?

BACKGROUND: Monitoring trends in community opinion can identify critical opportunities to implement upstream health policies or interventions. Our study examines change and demographic modifiers of change in community perceptions of government intervention for prevention of lifestyle-related chronic disease across two time points in Australia. METHODS: Data were drawn from the 2016 (n = 2052) and 2018 (n = 2601) waves of a nationally representative cross-sectional telephone survey, 'AUSPOPS'. Survey questions gauged perceptions of government intervention for health in general, peoples'/organizations' role in maintaining health (e.g., parents, government) and support for specific health interventions (e.g., taxing soft drink). Bivariate and multivariate regression models tested for change between the two surveys, adjusted for demographic characteristics. Models with interactions between survey wave and demographic variables tested for differential change. One-tailed variance ratio tests examined whether opinions had become more polarized in 2018 compared with 2016. RESULTS: The large, significant increase observed in the perceived size of the role that government has in maintaining people's health was uniform across demographic subpopulations. The role for employers and private health insurers was also perceived to be larger in 2018 compared with 2016, but the degree of change varied by gender, age and/or socioeconomic status. Support for some government interventions (e.g., taxing soft drinks) increased among specific demographic subgroups whilst exhibiting no overall change. Opinion was more polarized on general attitudes to government intervention for population health in 2018 compared to 2016, despite little change in central tendency. CONCLUSIONS: Opportunities may exist to implement government health-promoting policies (e.g., taxing soft drinks), although advocacy may be needed to address the concerns of less supportive subpopulations. Attitudes on government intervention in general may be becoming more polarized; future research examining the association of such changes with exposure to different information sources could inform communication strategies for future health policy change

The infrared imaging spectrograph (IRIS) for TMT: spectrograph design

The Infra-Red Imaging Spectrograph (IRIS) is one of the three first light instruments for the Thirty Meter Telescope (TMT) and is the only one to directly sample the diffraction limit. The instrument consists of a parallel imager and off-axis Integral Field Spectrograph (IFS) for optimum use of the near infrared (0.84um-2.4um) Adaptive Optics corrected focal surface. We present an overview of the IRIS spectrograph that is designed to probe a range of scientific targets from the dynamics and morphology of high-z galaxies to studying the atmospheres and surfaces of solar system objects, the latter requiring a narrow field and high Strehl performance. The IRIS spectrograph is a hybrid system consisting of two state of the art IFS technologies providing four plate scales (4mas, 9mas, 25mas, 50mas spaxel sizes). We present the design of the unique hybrid system that combines the power of a lenslet spectrograph and image slicer spectrograph in a configuration where major hardware is shared. The result is a powerful yet economical solution to what would otherwise require two separate 30m-class instruments.Comment: 15 pages, 11 figure

EFFECTS OF HERBICIDES AND GRAZING ON FLORISTIC QUALITY OF NATIVE TALLGRASS PASTURES IN EASTERN SOUTH DAKOTA AND SOUTHWESTERN MINNESOTA

Historic herbicide use and grazing have influenced natural diversity and quality of native pasturelands in the Great Plains. Floristic quality assessments are useful to assist agencies in prioritizing conservation practices to enhance native grasslands. The objective of this study was to determine the effects of past land-use practices on the floristic quality of remnant native pastures in eastern South Dakota and southwestern Minnesota. Floristic quality assessments were conducted on 30 native pastures and categorized by past management practices (herbicide application and grazing intensity). Mean coefficient of conservatism (C) and floristic quality index (FQI) were calculated for each site~Results showed that increased herbicide use and grazing intensity resulted in a lower species richness, forb C ,and FQI. However, grass and grasslike plants were minimally affected. Pastures that were infrequently sprayed with herbicides and lightly grazed consistently had the highest species richness, C ,and FQI. Pastures with no grazing produced similar values to those with moderate grazing. Pastures managed as preserves or wildlife habitat areas had higher FQI than those managed for livestock grazing. The implications of this study should further help ecologists and managers understand the positive and negative effects of grazing practices and herbicide application on tallgrass prairie remnants

Personal, Social, and Environmental Mediators Associated With Increased Recreational Physical Activity in Women and Girls in the Kingdom of Tonga.

BACKGROUND: The purpose of this paper was to identify personal, social, and environmental mediators of recreational physical activity (PA) in a 6-month netball-based intervention for women and girls in Tonga. METHODS: Tonga Netball's "low-engagement village program" was implemented in 10 villages and aimed to increase the recreational PA levels in women and girls through a comprehensive, structured community-level netball program addressing key barriers to participation. In a mixed-methods approach, these mediating barriers were identified through qualitative interviews based on the socioecological model. Quantitative measures for mediators and recreational PA were then developed, and data from 301 women and girls were collected. Standard mediation analyses methods were then applied. RESULTS: Program participation appeared to significantly increase PA levels. Statistically significant personal mediators were body issues, preferring competitions, and clothing. Social mediators were support from sports council, community leaders, friends, and church. Environmental mediators were travel time and access to balls, bibs, and umpires. CONCLUSION: A comprehensive community-level program addressing key participation barriers can increase recreational PA among women and girls in Tonga. Triangulating these results with mediation analyses of variables on the causal pathway can strengthen our understanding of causation and inform funding prioritization for critical program components in similar contexts