949 research outputs found
MPST Software: grl_pef_check
This innovation is a tool used to verify and validate spacecraft sequences at the predicted events file (PEF) level for the GRAIL (Gravity Recovery and Interior Laboratory, see http://www.nasa. gov/mission_pages/grail/main/index. html) mission as part of the Multi-Mission Planning and Sequencing Team (MPST) operations process to reduce the possibility for errors. This tool is used to catch any sequence related errors or issues immediately after the seqgen modeling to streamline downstream processes. This script verifies and validates the seqgen modeling for the GRAIL MPST process. A PEF is provided as input, and dozens of checks are performed on it to verify and validate the command products including command content, command ordering, flight-rule violations, modeling boundary consistency, resource limits, and ground commanding consistency. By performing as many checks as early in the process as possible, grl_pef_check streamlines the MPST task of generating GRAIL command and modeled products on an aggressive schedule. By enumerating each check being performed, and clearly stating the criteria and assumptions made at each step, grl_pef_check can be used as a manual checklist as well as an automated tool. This helper script was written with a focus on enabling the user with the information they need in order to evaluate a sequence quickly and efficiently, while still keeping them informed and active in the overall sequencing process. grl_pef_check verifies and validates the modeling and sequence content prior to investing any more effort into the build. There are dozens of various items in the modeling run that need to be checked, which is a time-consuming and errorprone task. Currently, no software exists that provides this functionality. Compared to a manual process, this script reduces human error and saves considerable man-hours by automating and streamlining the mission planning and sequencing task for the GRAIL mission
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Particulate Matter Air Pollution Exposure, Distance to Road, and Incident Lung Cancer in the Nursesâ Health Study Cohort
Background: A body of literature has suggested an elevated risk of lung cancer associated with particulate matter and traffic-related pollutants. Objective: We examined the relation of lung cancer incidence with long-term residential exposures to ambient particulate matter and residential distance to roadway, as a proxy for traffic-related exposures. Methods: For participants in the Nursesâ Health Study, a nationwide prospective cohort of women, we estimated 72-month average exposures to PM2.5, PM2.5â10, and PM10 and residential distance to road. Follow-up for incident cases of lung cancer occurred from 1994 through 2010. Cox proportional hazards models were adjusted for potential confounders. Effect modification by smoking status was examined. Results: During 1,510,027 person-years, 2,155 incident cases of lung cancer were observed among 103,650 participants. In fully adjusted models, a 10-Îźg/m3 increase in 72-month average PM10 [hazard ratio (HR) = 1.04; 95% CI: 0.95, 1.14], PM2.5 (HR = 1.06; 95% CI: 0.91, 1.25), or PM2.5â10 (HR = 1.05; 95% CI: 0.92, 1.20) was positively associated with lung cancer. When the cohort was restricted to never-smokers and to former smokers who had quit at least 10 years before, the associations appeared to increase and were strongest for PM2.5 (PM10: HR = 1.15; 95% CI: 1.00, 1.32; PM2.5: HR = 1.37; 95% CI: 1.06, 1.77; PM2.5â10: HR = 1.11; 95% CI: 0.90, 1.37). Results were most elevated when restricted to the most prevalent subtype, adenocarcinomas. Risks with roadway proximity were less consistent. Conclusions: Our findings support those from other studies indicating increased risk of incident lung cancer associated with ambient PM exposures, especially among never- and long-term former smokers. Citation: Puett RC, Hart JE, Yanosky JD, Spiegelman D, Wang M, Fisher JA, Hong B, Laden F. 2014. Particulate matter air pollution exposure, distance to road, and incident lung cancer in the Nursesâ Health Study Cohort. Environ Health Perspect 122:926â932; http://dx.doi.org/10.1289/ehp.130749
Comparison of the Temporal Variability of Enterococcal Clusters in Impacted Streams Using a Multiplex Polymerase Chain Reaction Procedure
Proceedings of the 2007 Georgia Water Resources Conference, March 27-29, 2007, Athens, Georgia.Understanding how fecal indicator bacteria and/or fecal indicator genotypes vary over time is important to determine the sources of fecal contamination. Enterococcus is one of the two indicators recommended by the EPA to monitor freshwaters for fecal contamination. Along with Escherichia coli, it has been used by a number of researchers to infer sources of fecal contamination, an area identified as microbial source tracking (MST). Our objective in this study was to identify changes in the seasonal distribution of enterococcal populations in streams directly impacted by cattle farming. The sites under study are located in Madison County, Ga., in farms where cows have unrestricted access to first order streams. Enterococci were counted and isolated monthly from water samples using membrane filtration. The isolates were identified using a multiplex PCR procedure. From a total of nine species identified in stream samples, only the most frequently observed species (E. faecalis, E. casseliflavus, E. flavescens, E. faecium and E. hirae) were used to develop groupings of enterococcal populations via cluster analysis. This analysis revealed that E. casseliflavus and E. faecalis dominated the enterococcal community during spring and fall, respectively. The cluster dominated by E. faecium seemed to increase during winter. This study indicates that enterococcal communities exhibit seasonal variability; and suggests that cluster analysis is a robust approach to identify this variability. In conclusion, to determine the true impact of certain farming operations on stream water quality using enterococcal species as indicators, it is important to consider the temporal variability of key enterococcal communities.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, Natural Resources Conservation Service, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1990 (P.L. 101-397) or the other conference sponsors
Quantum phase transitions of light
Recently, condensed matter and atomic experiments have reached a length-scale
and temperature regime where new quantum collective phenomena emerge. Finding
such physics in systems of photons, however, is problematic, as photons
typically do not interact with each other and can be created or destroyed at
will. Here, we introduce a physical system of photons that exhibits strongly
correlated dynamics on a meso-scale. By adding photons to a two-dimensional
array of coupled optical cavities each containing a single two-level atom in
the photon-blockade regime, we form dressed states, or polaritons, that are
both long-lived and strongly interacting. Our zero temperature results predict
that this photonic system will undergo a characteristic Mott insulator
(excitations localised on each site) to superfluid (excitations delocalised
across the lattice) quantum phase transition. Each cavity's impressive photon
out-coupling potential may lead to actual devices based on these quantum
many-body effects, as well as observable, tunable quantum simulators. We
explicitly show that such phenomena may be observable in micro-machined diamond
containing nitrogen-vacancy colour centres and superconducting microwave
strip-line resonators.Comment: 11 pages, 5 figures (2 in colour
A River Continuum Analysis of an Anthropogenically-Impacted System: The Little Bear River, Utah
In September 2012 the Aquatic Ecology Practicum class from Utah State University studied the 51km river continuum of the Little Bear River located in northern Utah (Figure 1). The relatively pristine headwaters of the river begin in the Wasatch Mountain Range at an altitude of 1800 m. The river flows northward into Cache Valley where it terminates in Cutler Reservoir (1345 m elevation). Agricultural development and urbanization have modified the natural terrain and chemical characteristics of the river, and Hyrum Reservoir, located midway along the gradient causes a discontinuity in river processes. The results from analyses of stream condition indicators from up to eleven stations along the gradient were interpreted within the context of the River Continuum Concept (Vannote et al. 1980) and the Serial Discontinuity Hypothesis (Ward and Stanford 1983)
Ecological Modeling of Aedes aegypti (L.) Pupal Production in Rural Kamphaeng Phet, Thailand
Background - Aedes aegypti (L.) is the primary vector of dengue, the most important arboviral infection globally. Until an effective vaccine is licensed and rigorously administered, Ae. aegypti control remains the principal tool in preventing and curtailing dengue transmission. Accurate predictions of vector populations are required to assess control methods and develop effective population reduction strategies. Ae. aegypti develops primarily in artificial water holding containers. Release recapture studies indicate that most adult Ae. aegypti do not disperse over long distances. We expect, therefore, that containers in an area of high development site density are more likely to be oviposition sites and to be more frequently used as oviposition sites than containers that are relatively isolated from other development sites. After accounting for individual container characteristics, containers more frequently used as oviposition sites are likely to produce adult mosquitoes consistently and at a higher rate. To this point, most studies of Ae. aegypti populations ignore the spatial density of larval development sites. Methodology - Pupal surveys were carried out from 2004 to 2007 in rural Kamphaeng Phet, Thailand. In total, 84,840 samples of water holding containers were used to estimate model parameters. Regression modeling was used to assess the effect of larval development site density, access to piped water, and seasonal variation on container productivity. A varying-coefficients model was employed to account for the large differences in productivity between container types. A two-part modeling structure, called a hurdle model, accounts for the large number of zeroes and overdispersion present in pupal population counts. Findings - The number of suitable larval development sites and their density in the environment were the primary determinants of the distribution and abundance of Ae. aegypti pupae. The productivity of most container types increased significantly as habitat density increased. An ecological approach, accounting for development site density, is appropriate for predicting Ae. aegypti population levels and developing efficient vector control program
Survival and regrowth of fecal enterococci in desiccated and rewetted sediments
Fecal enterococci are bacteria widely used as indicators of fecal contamination in marine and estuarine waters. One assumption is that these bacteria do not persist or regrow in the environment. Our continuing problems with high numbers of fecal enterococci in sediment suggested that these bacteria may persist and regrow. Therefore, we conducted experiments with fecal enterococci to determine their ability to survive desiccation and to regrow in marine and estuarine sediments from Georgia, New Hampshire, and Puerto Rico after 0, 2, 30, and 60 days. Although numbers of fecal enterococci generally decreased with increased length of drying, many fecal enterococci survived desiccation and regrew in rewetted sediment, violating the assumption that fecal bacteria not persist or regrow in the environment. Because there is not a better alternative to fecal enterococci as fecal indicator bacteria, these results suggest that care should be taken not to disturb the sediment when sampling water for fecal contamination, or if the sediment is already disturbed (e.g., on windy days or during runoff conditions), then the influence of sediment should be considered.Sponsored by:
Georgia Environmental Protection Division
U.S. Geological Survey, Georgia Water Science Center
U.S. Department of Agriculture, Natural Resources Conservation Service
Georgia Institute of Technology, Georgia Water Resources Institute
The University of Georgia, Water Resources Facult
Interactive PowerPoint Training to Improve Safety Driver Awareness while Operating a Transit Vehicle Equipped with Driving Automation Features
As new technologies, such as advanced driver assistance systems (ADAS) and automated driving systems (ADS) are introduced into transit operations, the tasks required of the operator will change. This research effort sought to understand if a low-cost training tool could be developed to maintain/improve safety as transit agencies pilot test these technologies. The program that was developed used an error training approach to improve hazard anticipation, hazard mitigation, and attention maintenance. This preliminary pilot study was conducted with federal employees and showed significant improvements across all three of the training areas
Measurement of Ď c1 and Ď c2 production with sâ = 7 TeV pp collisions at ATLAS
The prompt and non-prompt production cross-sections for the Ď c1 and Ď c2 charmonium states are measured in pp collisions at sâ = 7 TeV with the ATLAS detector at the LHC using 4.5 fbâ1 of integrated luminosity. The Ď c states are reconstructed through the radiative decay Ď c â J/ĎÎł (with J/Ď â Îź + Îź â) where photons are reconstructed from Îł â e + e â conversions. The production rate of the Ď c2 state relative to the Ď c1 state is measured for prompt and non-prompt Ď c as a function of J/Ď transverse momentum. The prompt Ď c cross-sections are combined with existing measurements of prompt J/Ď production to derive the fraction of prompt J/Ď produced in feed-down from Ď c decays. The fractions of Ď c1 and Ď c2 produced in b-hadron decays are also measured
Standalone vertex ďŹnding in the ATLAS muon spectrometer
A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at âs = 7 TeV collected with the ATLAS detector at the LHC during 2011
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