Mwanza J.-C.,National Research Council Italy |
Mwanza J.-C.,University of North Carolina at Chapel Hill |
Lyke D.F.,National Health and Environmental Effects Research Laboratory |
Hertzberg R.C.,Biomathematics Consulting |
And 10 more authors.
NeuroToxicology | Year: 2012
Previously, we reported that acute treatment with propoxur or carbaryl decreased the duration of the Photic After Discharge (PhAD) of Flash Evoked Potentials (FEPs). In the current studies, we compared the effects of acute or repeated exposure to a mixture of carbaryl and propoxur (1:1.45 ratio; propoxur:carbaryl) on the duration of the PhAD and brain ChE activity in Long Evans rats. Animals were exposed (po) either to a single dose (0, 3, 10, 45 or 75. mg/kg), or 14 daily dosages (0, 3, 10, 30, 45. mg/kg), of the mixture. Acute and repeated treatment with 3. mg/kg (or greater) of the mixture produced dose-related inhibition of brain ChE activity. Compared to controls, the PhAD duration decreased after acute administration of 75. mg/kg or repeated treatment with 30. mg/kg of the mixture. The linear relationship between the percent of control brain ChE activity and the PhAD duration was similar for both exposure paradigms. Dose-response models for the acute and repeated exposure data did not differ for brain ChE activity or the duration of the PhAD. Repeated treatment with the mixture resulted in slightly less (13-22%) erythrocyte ChE inhibition than acute exposure. Both acute and repeated treatment resulted in dose-additive results for the PhAD duration and less than dose-additive responses (6-16%) for brain ChE activity for the middle range of dosages. Acute treatment resulted in greater than dose-additive erythrocyte ChE inhibition (15-18%) at the highest dosages. In contrast, repeated treatment resulted in less than dose-additive erythrocyte ChE inhibition (16-22%) at the middle dosages. Brain and plasma levels of propoxur and carbaryl did not differ between the acute and repeated dosing paradigms. In summary, a physiological measure of central nervous system function and brain ChE activity had similar responses after acute or repeated treatment with the carbamate mixture, and brain ChE showed only small deviations from dose-additivity. Erythrocyte ChE activity had larger differences between the acute and repeated treatment paradigms, and showed slightly greater deviations from dose-additivity. Because these treatments utilized larger dosages than anticipated environmental exposures, concern for non-additive effects in humans is minimized. The small magnitude of the deviations from dose-additivity also suggest that in the absence of repeated exposure data, results from an acute study of readily reversible carbamate toxicity can be used to estimate the response to repeated daily exposures. © 2012 .
Zhang Y.,National Oceanic and Atmospheric Administration |
Seo D.-J.,National Oceanic and Atmospheric Administration |
Kitzmiller D.,National Oceanic and Atmospheric Administration |
Lee H.,National Oceanic and Atmospheric Administration |
And 3 more authors.
Journal of Hydrometeorology | Year: 2013
This paper assesses the accuracy of satellite quantitative precipitation estimates (QPEs) from two versions of the Self-Calibrating Multivariate Precipitation Retrieval (SCaMPR) algorithm relative to that of gridded gauge-only QPEs. The second version of SCaMPR uses the QPEs from Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar and Microwave Imager as predictands whereas the first version does not. The assessments were conducted for 22 catchments in Texas and Louisiana against National Weather Service operational multisensor QPE. Particular attention was given to the density below which SCaMPR QPEs outperform gauge-only QPEs and effects of TRMM ingest. Analyses indicate that SCaMPR QPEs can be competitive in terms of correlation and CSI against sparse gauge networks (with less than one gauge per 3200-12 000 km2) and over 1-3-h scale, but their relative strengths diminish with temporal aggregation. In addition, the major advantage of SCaMPR QPEs is its relatively low false alarm rates, whereas gauge-only QPEs exhibit better skill in detecting rainfall-though the detection skill of SCaMPR QPEs tends to improve at higher rainfall thresholds. Moreover, it was found that ingesting TRMM QPEs help mitigate the positive overall bias in SCaMPR QPEs, and improve the detection of moderate-heavy and particularly wintertime precipitation. Yet, it also tends to elevate the false alarm rate, and its impacts on detection rates can be slightly negative for summertime storms. The implications for adoption of TRMM and Global Precipitation Measurement (GPM) QPEs for NWS operations are discussed. © 2013 American Meteorological Society.
PubMed | National Institute of Environmental Health science, National Office Systems and Open Intelligence Inc.
Type: Journal Article | Journal: Scientometrics | Year: 2016
As federal programs are held more accountable for their research investments, The National Institute of Environmental Health Sciences (NIEHS) has developed a new method to quantify the impact of our funded research on the scientific and broader communities. In this article we review traditional bibliometric analyses, address challenges associated with them, and describe a new bibliometric analysis method, the Automated Research Impact Assessment (ARIA). ARIA taps into a resource that has only rarely been used for bibliometric analyses: references cited in important research artifacts, such as policies, regulations, clinical guidelines, and expert panel reports. The approach includes new statistics that science managers can use to benchmark contributions to research by funding source. This new method provides the ability to conduct automated impact analyses of federal research that can be incorporated in program evaluations. We apply this method to several case studies to examine the impact of NIEHS funded research.
Whitcraft A.K.,University of Maryland University College |
Becker-Reshef I.,University of Maryland University College |
Killough B.D.,National Office Systems |
Justice C.O.,University of Maryland University College
Remote Sensing | Year: 2015
Agriculture is a highly dynamic process in space and time, with many applications requiring data with both a relatively high temporal resolution (at least every 8 days) and fine-to-moderate (FTM < 100 m) spatial resolution. The relatively infrequent revisit of FTM optical satellite observatories coupled with the impacts of cloud occultation have translated into a barrier for the derivation of agricultural information at the regional-to-global scale. Drawing upon the Group on Earth Observations Global Agricultural Monitoring (GEOGLAM) Initiative's general satellite Earth observation (EO) requirements for monitoring of major production areas, Whitcraft et al. (this issue) have described where, when, and how frequently satellite data acquisitions are required throughout the agricultural growing season at 0.05°, globally. The majority of areas and times of year require multiple revisits to probabilistically yield a view at least 70%, 80%, 90%, or 95% clear within eight days, something that no present single FTM optical observatory is capable of delivering. As such, there is a great potential to meet these moderate spatial resolution optical data requirements through a multi-space agency/multi-mission constellation approach. This research models the combined revisit capabilities of seven hypothetical constellations made from five satellite sensors-Landsat 7 Enhanced Thematic Mapper (Landsat 7 ETM+), Landsat 8 Operational Land Imager and Thermal Infrared Sensor (Landsat 8 OLI/TIRS), Resourcesat-2 Advanced Wide Field Sensor (Resourcesat-2 AWiFS), Sentinel-2A Multi-Spectral Instrument (MSI), and Sentinel-2B MSI-and compares these capabilities with the revisit frequency requirements for a reasonably cloud-free clear view within eight days throughout the agricultural growing season. Supplementing Landsat 7 and 8 with missions from different space agencies leads to an improved capacity to meet requirements, with Resourcesat-2 providing the largest incremental improvement in requirements met. The best performing constellation can meet 71%-91% of the requirements for a view at least 70% clear, and 45%-68% of requirements for a view at least 95% clear, varying by month. Still, gaps exist in persistently cloudy regions/periods, highlighting the need for data coordination and for consideration of active EO for agricultural monitoring. This research highlights opportunities, but not actual acquisition rates or data availability/access; systematic acquisitions over actively cropped agricultural areas as well as a policy which guarantees continuous access to high quality, interoperable data are essential in the effort to meet EO requirements for agricultural monitoring.
Sierra-Santoyo A.,National Office Systems |
Sierra-Santoyo A.,CINVESTAV |
Angeles-Soto E.,CINVESTAV |
Lopez-Gonzalez Ma.D.L.,CINVESTAV |
And 2 more authors.
Archives of Toxicology | Year: 2012
Vinclozolin (V) is a fungicide used in agricultural settings. V administered to rats is hydrolyzed to 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2- methyl-3-butenoic acid (M1) and 3′,5′-dichloro-2-hydroxy-2- methylbut-3-enanilide (M2). V, M1 and M2 have antiandrogenic properties by interacting with the androgen receptor. Data on V, M1 and M2 biotransformation are limited. Our objective was to characterize V metabolism by rat liver microsomes. V was incubated with non-treated adult male Long-Evans rat liver microsomes and NADPH. Several metabolites were detected following the extraction of incubate with acetonitrile and analysis by HPLC/DAD/MSD. One metabolite was identified as [3-(3,5-dichlorophenyl)-5-methyl-5-(1,2-dihydroxyethyl)-1,3- oxazolidine-2,4-dione] (M4), which was gradually converted to 3′,5′-dichloro-2,3,4-trihydroxy-2-methylbutylanilide (M5). Both co-eluted in the same HPLC peak. Another metabolite ([M7]) was detected by UV but was unstable for mass spectral analysis. The K M app for co-eluted M4/M5 and [M7] was 53.7 and 135.4 μM, the V max app was 0.812 and 0.669 nmoles/min/mg protein, and CL int was 15.1 and 4.9 ml/min/g protein, respectively. Pilocarpine, orphenadrine and proadifen and anti-rat cytochrome P450 (CYP)2A, 2B and 3A antibodies inhibited M4/M5 and [M7] formation. These results indicate that V is efficiently metabolized by CYP. Determination of the metabolites of V will provide further insight into the relationship between toxicity and tissue dose of V and its metabolites. © 2011 Springer-Verlag.
Duran A.,Tecnicas de Salud |
Duran A.,National Office Systems |
Khot A.,National Office Systems
Indian Journal of Community Medicine | Year: 2011
The paper emphasizes the vital need to address the rising burden of noncommunicable diseases (NCDs) in India with a health systems approach. The authors argue that adoption of such approach may soon be imperative. Applying the health systems framework developed by the WHO in 2000 to NCDs means in summary re-examining the planning and organization of the entire health system, from service provision to financing, from information generation to ensuring adequate supply of pharmaceuticals/technologies or human resources, from improving facility management to performance monitoring. Using this framework the authors seek to highlight core issues and identify possible policy actions required. The challenge is to ensure the best implementation of what works, aligning the service provision function with the financial incentives, ensuring leadership/stewardship by the government across local/municipal, state or regional and national level while involving stakeholders. A health system perspective would also ensure that action against NCD goes hand in hand with tackling the remaining burden from communicable diseases, maternal, child health and nutrition issues.
Zhang Q.,Hamner Institutes for Health Sciences |
Bhattacharya S.,Hamner Institutes for Health Sciences |
Andersen M.E.,Hamner Institutes for Health Sciences |
Conolly R.B.,National Office Systems
Journal of Toxicology and Environmental Health - Part B: Critical Reviews | Year: 2010
The new paradigm envisioned for toxicity testing in the 21st century advocates shifting from the current animal-based testing process to a combination of in vitro cell-based studies, high-throughput techniques, and in silico modeling. A strategic component of the vision is the adoption of the systems biology approach to acquire, analyze, and interpret toxicity pathway data. As key toxicity pathways are identified and their wiring details elucidated using traditional and high-throughput techniques, there is a pressing need to understand their qualitative and quantitative behaviors in response to perturbation by both physiological signals and exogenous stressors. The complexity of these molecular networks makes the task of understanding cellular responses merely by human intuition challenging, if not impossible. This process can be aided by mathematical modeling and computer simulation of the networks and their dynamic behaviors. A number of theoretical frameworks were developed in the last century for understanding dynamical systems in science and engineering disciplines. These frameworks, which include metabolic control analysis, biochemical systems theory, nonlinear dynamics, and control theory, can greatly facilitate the process of organizing, analyzing, and understanding toxicity pathways. Such analysis will require a comprehensive examination of the dynamic properties of network motifsthe basic building blocks of molecular circuits. Network motifs like feedback and feedforward loops appear repeatedly in various molecular circuits across cell types and enable vital cellular functions like homeostasis, all-or-none response, memory, and biological rhythm. These functional motifs and associated qualitative and quantitative properties are the predominant source of nonlinearities observed in cellular dose response data. Complex response behaviors can arise from toxicity pathways built upon combinations of network motifs. While the field of computational cell biology has advanced rapidly with increasing availability of new data and powerful simulation techniques, a quantitative orientation is still lacking in life sciences education to make efficient use of these new tools to implement the new toxicity testing paradigm. A revamped undergraduate curriculum in the biological sciences including compulsory courses in mathematics and analysis of dynamical systems is required to address this gap. In parallel, dissemination of computational systems biology techniques and other analytical tools among practicing toxicologists and risk assessment professionals will help accelerate implementation of the new toxicity testing vision. Copyright © Taylor & Francis Group, LLC.
Muscatello A.,National Office Systems |
Devor R.,QinetiQ |
Captain J.,National Office Systems
Earth and Space 2014: Engineering for Extreme Environments - Proceedings of the 14th Biennial International Conference on Engineering, Science, Construction, and Operations in Challenging Environments | Year: 2014
The multi-NASA center Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project was established to build and demonstrate a methane/oxygen propellant production system in a Mars analog environment. Work at the Kennedy Space Center (KSC) has focused on the Atmospheric Processing Module (APM). The purpose of the APM is to freeze carbon dioxide from a simulated Martian atmosphere at Martian pressures (a8 torr) by using dual cryocoolers. The resulting pressurized CO2 and hydrogen are fed to a Sabatier subsystem to make methane and water vapor. This paper covers (1) the design and selection of major hardware items, such as the cryocoolers, pumps, tanks, chillers, and membrane separators, (2) the determination of the optimal cold head design and flow rates needed to meet the collection requirement of 88 g CO2/hr for 14 hr, (3) the testing of the CO2 freezer subsystem, and (4) testing of the Sabatier subsystem.
Hughes M.F.,National Office Systems |
Long T.C.,National Office Systems |
Long T.C.,U.S. Environmental Protection Agency |
Boyes W.K.,National Office Systems |
Ramabhadran R.,National Office Systems
Nanotoxicology | Year: 2013
Zerovalent iron nanoparticles (nZVI) are used for in situ remediation of contaminated ground water, raising the possibility that nZVI particles or their altered residues could contaminate the ground water. Therefore, it is important to study their effects on humans and other organisms in vivo. The objective of this study was to assess the whole-body retention and terminal disposition of neutron-activated radioactive nZVI administered by oral gavage in mice. Radioactivity was primarily eliminated in the faeces within 1 day of administration. However, a small amount of iron-derived radioactivity appeared in the liver after three repeated daily doses. This prototypic study further suggests that neutron activation applied judiciously may be broadly applicable to studies of nanoparticles derived from other biologically abundant metals. © 2013 Informa UK, Ltd.