323 research outputs found
Embedded Relative Navigation Sensor Fusion Algorithms for Autonomous Rendezvous and Docking Missions
bd Systems (a subsidiary of SAIC) has developed a suite of embedded relative navigation sensor fusion algorithms to enable NASA autonomous rendezvous and docking (AR&D) missions. Translational and rotational Extended Kalman Filters (EKFs) were developed for integrating measurements based on the vehicles' orbital mechanics and high-fidelity sensor error models and provide a solution with increased accuracy and robustness relative to any single relative navigation sensor. The filters were tested tinough stand-alone covariance analysis, closed-loop testing with a high-fidelity multi-body orbital simulation, and hardware-in-the-loop (HWIL) testing in the Marshall Space Flight Center (MSFC) Flight Robotics Laboratory (FRL)
A web server for inferring the human N-acetyltransferase-2 (NAT2) enzymatic phenotype from NAT2 genotype
Summary:N-acetyltransferase-2 (NAT2) is an important enzyme that catalyzes the acetylation of aromatic and heterocyclic amine carcinogens. Individuals in human populations are divided into three NAT2 acetylator phenotypes: slow, rapid and intermediate. NAT2PRED is a web server that implements a supervised pattern recognition method to infer NAT2 phenotype from SNPs found in NAT2 gene positions 282, 341, 481, 590, 803 and 857. The web server can be used for a fast determination of NAT2 phenotypes in genetic screens
Transmission of Human Papillomavirus in Heterosexual Couples
Rate of transmission from penis to cervix was lower than that from cervix to penis; 13 different genotypes were sexually transmitted
Anthropogenic Control over Wintertime Oxidation of Atmospheric Pollutants
Anthropogenic air pollutants such as nitrogen oxides (NO(x) = NO + NO(2)), sulfur dioxide (SO(2)), and volatile organic compounds (VOC), among others, are emitted to the atmosphere throughout the year from energy production and use, transportation, and agriculture. These primary pollutants lead to the formation of secondary pollutants such as fine particulate matter (PM(2.5)) and ozone (O(3)) and perturbations to the abundance and lifetimes of short-lived greenhouse gases. Free radical oxidation reactions driven by solar radiation govern the atmospheric lifetimes and transformations of most primary pollutants and thus their spatial distributions. During winter in the mid and high latitudes, where a large fraction of atmospheric pollutants are emitted globally, such photochemical oxidation is significantly slower. Using observations from a highly instrumented aircraft, we show that multi-phase reactions between gas-phase NO(x) reservoirs and aerosol particles, as well as VOC emissions from anthropogenic activities, lead to a suite of atypical radical precursors dominating the oxidizing capacity in polluted winter air, and thus, the distribution and fate of primary pollutants on a regional to global scale
Science Communication Demands a Critical Approach That Centers Inclusion, Equity, and Intersectionality
We live in an era of abundant scientific information, yet access to information and to opportunities for substantive public engagement with the processes and outcomes of science are still inequitably distributed. Even with increasing interest in science communication and public engagement with science, historically marginalized and minoritized individuals and communities are largely overlooked and undervalued in these efforts. To address this gap, this paper aims to define inclusive science communication and clarify and amplify the field. We present inclusive science communication as one path forward to redress the systemic problems of inequitable access to and engagement with STEMM (science, technology, engineering, mathematics, and medicine). We describe the first national Inclusive Science Communication (InclusiveSciComm) Symposium held in the U.S. Based on the experience of organizing the symposium, we discuss recommendations for other convenings to help build a community of practice for inclusive science communication. In both research and practice, we advocate for more experimentation to help make inclusive science communication the future of science communication writ large, in order to engage diverse publics in their multiple ways of knowing and expand a sense of belonging in STEMM
The ACOS CO_2 retrieval algorithm – Part 1: Description and validation against synthetic observations
This work describes the NASA Atmospheric CO_2 Observations from Space (ACOS) X_(CO_2) retrieval algorithm, and its performance on highly realistic, simulated observations. These tests, restricted to observations over land, are used to evaluate retrieval errors in the face of realistic clouds and aerosols, polarized non-Lambertian surfaces, imperfect meteorology, and uncorrelated instrument noise. We find that post-retrieval filters are essential to eliminate the poorest retrievals, which arise primarily due to imperfect cloud screening. The remaining retrievals have RMS errors of approximately 1 ppm. Modeled instrument noise, based on the Greenhouse Gases Observing SATellite (GOSAT) in-flight performance, accounts for less than half the total error in these retrievals. A small fraction of unfiltered clouds, particularly thin cirrus, lead to a small positive bias of ~0.3 ppm. Overall, systematic errors due to imperfect characterization of clouds and aerosols dominate the error budget, while errors due to other simplifying assumptions, in particular those related to the prior meteorological fields, appear small
Binge Eating and Weight-Related Quality of Life in Obese Adolescents
Limited data exist regarding the association between binge eating and quality of life (QOL) in obese adolescent girls and boys. We, therefore, studied binge eating and QOL in 158 obese (BMI ≥ 95th percentile) adolescents (14.5 ± 1.4 years, 68.0% female, 59% African-American) prior to weight-loss treatment. Youth completed an interview to assess binge eating and a questionnaire measure of QOL. Controlling for body composition, binge eating youth (n = 35), overall, reported poorer QOL in domains of health, mobility, and self-esteem compared to those without binge eating (ps < 0.05). Also, girls, overall, reported poorer QOL than boys in activities of daily-living, mobility, self-esteem, and social/interpersonal functioning (ps < 0.05). Girls with binge eating reported the greatest impairments in activities of daily living, mobility, self-esteem, social/interpersonal functioning, and work/school QOL (ps < 0.05). Among treatment-seeking obese adolescents, binge eating appears to be a marker of QOL impairment, especially among girls. Prospective and treatment designs are needed to explore the directional relationship between binge eating and QOL and their impact on weight outcomes
Advancing the estimation of future climate impacts within the United States
Evidence of the physical and economic impacts of climate change is a
critical input to policy development and decision-making. In addition to the
magnitude of potential impacts, detailed estimates of where, when, and to
whom those damages may occur; the types of impacts that will be most
damaging; uncertainties in these damages; and the ability of adaptation to
reduce potential risks are all interconnected and important considerations.
This study utilizes the reduced-complexity model, the Framework for
Evaluating Damages and Impacts (FrEDI), to rapidly project economic and
physical impacts of climate change across 10 000 future scenarios for
multiple impact sectors, regions, and populations within the contiguous
United States (US). Results from FrEDI show that net national damages
increase overtime, with mean climate-driven damages estimated to reach
USD 2.9 trillion (95 % confidence interval (CI): USD 510 billion to USD 12 trillion)
annually by 2090. Detailed FrEDI results show that for the analyzed sectors
the majority of annual long-term (e.g., 2090) damages are associated with
climate change impacts to human health, including mortality attributable to
climate-driven changes in temperature and air pollution (O3 and
PM2.5) exposure. Regional results also show that annual long-term
climate-driven damages vary geographically. The Southeast (all regions are as defined in Fig. 5) is projected to
experience the largest annual damages per capita (mean: USD 9300 per person
annually; 95 % CI: USD 1800–USD 37 000 per person annually), whereas the
smallest damages per capita are expected in the Southwest (mean: USD 6300
per person annually; 95 % CI: USD 840–USD 27 000 per person annually).
Climate change impacts may also broaden existing societal inequalities,
with, for example, Black or African Americans being disproportionately affected by
additional premature mortality from changes in air quality. Lastly, FrEDI
projections are extended through 2300 to estimate the net present
climate-driven damages within US borders from marginal changes in
greenhouse gas emissions. Combined, this analysis provides the most detailed
illustration to date of the distribution of climate change impacts within
US borders.</p
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