Agency Method Research Articles

LEAPing Ahead – The Space Development Agency's Method for Planning for the Future

AbstractThe Space Development Agency (SDA) is a constructive disruptor within the Department of Defense, tasked with rapidly acquiring and delivering space‐based capabilities. SDA delivers dozens of satellites on two‐year cycles and this pace requires defined processes to ensure that the technology exists to support the required capabilities. SDA has developed a process called List, Evaluate, Achieve, Procure (LEAP) which is used to identify technologies that require additional development resources to meet both current Warfighter needs and those that will occur in the future. This paper provides an illustrative example of SDA applying the LEAP process to the development of SDA's optical communications terminals, demonstrating how it is used to identify critical technologies to be supported through investment opportunities that augment the system acquisitions.

Detection and molecular characterization of Cryptosporidium species and Giardia assemblages in two watersheds in the metropolitan region of São Paulo, Brazil

Cryptosporidium and Giardia are associated with cases of water and foodborne outbreaks in the world. This study included 50 samples of surface raw water collected from two watersheds in the state of São Paulo, Brazil. The isolation of (oo)cysts was performed in accordance with the U.S. Environmental Protection Agency's methods 1623 and genotypic characterization and quantification were carried out by Nested PCR and qPCR assays based on 18S rRNA and gdh genes, respectively. U.S. EPA 1623 method showed the presence of (oo)cysts in 40% ([Formula: see text] = 0.10oocysts/L) and 100% ([Formula: see text] = 7.6cysts/L) of samples from São Lourenço River, respectively, and 24% ([Formula: see text] = 0.8 oocysts/L) and 60% ([Formula: see text] = 1.64cysts/L) of Guarapiranga Reservoir, respectively. The qPCR assay detected C. hominis/parvum in 52% (0.06 to 1.85oocysts/L) of São Lourenço River and 64% (0.09 to 1.4oocysts/L) of Guarapiranga Reservoir samples. Presence/absence test for Giardia intestinalis was positive in 92% of São Lourenço River and 8% of Guarapiranga Reservoir samples. The assemblage A was detected in 16% (0.58 to 2.67cysts/L) in São Lourenço River and no positive samples were obtained for assemblage B in both water bodies. The characterization of anthroponotic species C. parvum/hominis, G. intestinalis, and assemblage A was valuable in the investigation of possible sources of contamination in the watersheds studied confirming the need of expanding environmental monitoring measures for protection of these water sources in our country.

Inflation of Type I Error in the Evaluation of Scaled Average Bioequivalence, and a Method for its Control.

To verify previously reported findings for the European Medicines Agency's method for Average Bioequivalence with Expanding Limits (ABEL) for assessing highly variable drugs and to extend the assessment for other replicate designs in a wide range of sample sizes and CVs. To explore the properties of a new modified method which maintains the consumer risk ≤0.05 in all cases. Monte-Carlo simulations of three different replicate designs covering a wide range of sample sizes and intra-subject variabilities were performed. At the switching variability of CV wR 30% the consumer risk is substantially inflated to up to 9.2%, which translates into a relative increase of up to 84%. The critical region of inflated type I errors ranges approximately from CV wR 25 up to 45%. The proposed method of iteratively adjusting α maintains the consumer risk at the desired level of ≤5% independent from design, variability, and sample size. Applying the European Medicines Agency's ABEL method at the nominal level of 0.05 inflates the type I error to an unacceptable degree, especially close to a CV wR of 30%. To control the type I error nominal levels ≤0.05 should be employed. Iteratively adjusting α is suggested to find optimal levels of the test.

Presence of Cryptosporidium parvum and Giardia lamblia in water samples from Southeast Asia: towards an integrated water detection system.

BackgroundAccess to clean and safe drinking water that is free from pathogenic protozoan parasites, especially Cryptosporidium parvum and Giardia lamblia that cause gastrointestinal illness in humans, is still an issue in Southeast Asia (SEA). This study is the first attempt to detect the aforementioned protozoan parasites in water samples from countries in SEA, using real-time polymerase chain reaction (qPCR) assays.MethodsA total of 221 water samples of 10 l each were collected between April and October 2013 from Malaysia (53), Thailand (120), the Philippines (33), and Vietnam (15). A physicochemical analysis was conducted. The water samples were processed in accordance with the US Environmental Protection Agency’s methods 1622/1623.1, microscopically observed and subsequently screened using qPCR assays.ResultsCryptosporidium oocysts were detected in treated water samples from the Philippines (1/10), with a concentration of 0.06 ± 0.19 oocyst/L, and untreated water samples from Thailand (25/93), Malaysia (17/44), and the Philippines (11/23), with concentrations ranging from 0.13 ± 0.18 to 0.57 ± 1.41 oocyst/L. Giardia cysts were found in treated water samples from the Philippines (1/10), with a concentration of 0.02 ± 0.06 cyst/L, and in untreated water samples from Thailand (20/93), Vietnam (5/10), Malaysia (22/44), and the Philippines (16/23), with concentrations ranging from 0.12 ± 0.3 to 8.90 ± 19.65 cyst/L. The pathogens C. parvum and G. lamblia were detected using using qPCR assays by targeting the 138-bp fragment and the small subunit gene, respectively. C. parvum was detected in untreated water samples from the Philippines (1/23) and Malaysia (2/44), whilst, G. lamblia detected was detected in treated water samples from the Philippines (1/10) and in untreated water samples from Thailand (21/93), Malaysia (12/44), and the Philippines (17/23). Nitrate concentration was found to have a high positive correlation with (oo)cyst (0.993).ConclusionThe presence of (oo)cysts in the water samples means that there is potential risk for zoonotic disease transmission in the studied countries. Detection using qPCR is feasible for quantifying both pathogenic C. parvum and G. lamblia in large water samples.

USEPA Approves On‐line Monitoring of Chlorine Residuals

This article discusses U.S. Environmental Protection Agency's Method 334.0, Determination of Residual Chlorine in Drinking Water Using an On‐line Chlorine Analyzer. Now utilities have an approved method specifically for on‐line chlorine residual monitoring. Online instruments operated according to the method will produce analytical results comparable to other approved methods and are suitable for compliance reporting under federal regulations. The method incorporates several quality assurance measures that utilities must incorporate in their standard operating procedures. This development is particularly important for utilities using on‐line amperometric chlorine analyzers, which have historically been used for process control. The article discusses key quality assurance and control procedures that include the following: the on‐line instrument is calibrated using aqueous standards or the results from paired grab samples collected at the same point and time; the grab samples are analyzed for chlorine using a method approved for drinking water compliance monitoring; the on‐line analyzer's accuracy is periodically verified and adjusted based on grab sample analysis results; and, the analyst demonstrates competency in using the method.

Application of speciated isotope dilution mass spectrometry to evaluate methods for efficiencies, recoveries, and quantification of mercury species transformations in human hair

Nine different analytical extraction methods commonly used for mercury speciation in human hair samples were evaluated by analyzing hair certified reference material (IAEA-085) certified for the content of monomethyl mercury and total mercury. Extraction efficiencies, recoveries, as well as their potential of species transformations during sample processing, were evaluated by applying speciated isotope dilution mass spectrometry (SIDMS) as both a quantitative and diagnostic tool. The extraction methods evaluated in this study were based on acid leaching with HCl and HNO3. Detection of total mercury and mercury species from all extraction methods were carried out by inductivley coupled plasma mass spectrometry (ICP-MS) and high performance liquid chromatography-ICP-MS, respectively. Microwave-assisted extraciton (4 mol l−1 HNO3, at 100 °C for 10 min) and mechanical shaking (2 mol l−1HCl, at room temperature for 24 h) were found to be the most efficient protocols that demonstrated approximately 100% mecury recovery with less species transformations (6% or less). Ultrasound-assisted extraction (2% HCl + 10% ethanol, at 60 °C for 7 min) or extraction with 2 mol l−lHCl in a water bath (at 100 °C for 5 min) resulted in the second highest extraction efficiency (∼90%) with little or no mercury species transformations. Demethylation as high as 22% using 5 mol l−1 HNO3 in a water-bath heating (at 100 °C for 2 h) and 90% with cold acid digestion using concentrated HNO3 and H2O2 (room temperature for 24 h) were observed, however, all the extraction methods tested produced accurate quantitation when corrected in accordance with the SIDMS method standardized in the US Environmental Protection Agency's method 6800.

Comparison of methods with respect to efficiencies, recoveries, and quantitation of mercury species interconversions in food demonstrated using tuna fish

Eight different analytical extraction procedures commonly used to extract mercury species from biological samples were evaluated by analyzing Tuna Fish Tissue Certified Reference Material (ERM-CE464) certified for the content of total mercury and methylmercury. Speciated isotope dilution mass spectrometry (SIDMS; US Environmental Protection Agency's method 6800) was utilized to evaluate and effectively compensate for potential errors during measurement and accurately quantify mercury species using all the extraction methods. SIDMS was used to accurately evaluate species transformations during sample pretreatment, preparation and analysis protocols. The extraction methods tested in this paper were based on alkaline extraction with KOH or tetramethylammonium hydroxide; acid leaching with HCl, HNO(3) or CH(3)COOH; extraction with L: -cysteine hydrochloride; and enzymatic digestion with protease XIV. Detection of total mercury and mercury species from all extraction methods was carried out by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography-ICP-MS, respectively. Microwave-assisted extraction and ultrasound-assisted extraction were found to be the most efficient alkaline digestion protocols that caused the lowest levels of transformation of mercury species (6% or less). Extraction with 5 M HCl or enzymatic digestion with protease resulted in the second-highest extraction efficiency, with relatively lower transformation of methylmercury to inorganic mercury (3 and 1.4%, respectively). Despite frequent use of acid leaching for the extraction of mercury species from tuna fish samples, the lowest extraction efficiencies and the highest mercury species transformation were obtained when microwave-assisted extraction with 4 M HNO(3) or CH(3)COOH was used. Transformations as high as 30% were found using some literature protocols; however, all the extractions tested produced accurate quantitation when corrected in accordance with the SIDMS method standardized in the US Environmental Protection Agency's method 6800. [figure: see text]

EPA ANALYSIS CALLED FAULTY

RETURN TO ISSUEPREVNewsNEXTEPA ANALYSIS CALLED FAULTYCongressional researchers say agency's methods skewed toward Bush emission planCHERYL HOGUECite this: Chem. Eng. News 2005, 83, 50, 8Publication Date (Print):December 12, 2005Publication History Published online14 November 2010Published inissue 12 December 2005https://doi.org/10.1021/cen-v083n050.p008Copyright © 2005 AMERICAN CHEMICAL SOCIETYArticle Views7Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (465 KB) SUBJECTS:Group 16 compounds,Mercury,Nitrogen,Oxides,Redox reactions Get e-Alerts

A Direct Comparison of U.S. Environmental Protection Agency's Method 304B and Batch Tests for Determining Activated‐Sludge Biodegradation Rate Constants for Volatile Organic Compounds

Biodegradation rate constants for volatile organic compounds (VOCs) in activated‐sludge systems are needed to quantify emissions. One current U.S. Environmental Protection Agency method for determining a biodegradation rate constant is Method 304B. In this approach, a specific activated‐sludge unit is simulated by a continuous biological treatment system with a sealed headspace. Batch experiments, however, can be alternatives to Method 304B. Two of these batch methods are the batch test that uses oxygen addition (BOX) and the serum bottle test (SBT). In this study, Method 304B was directly compared to BOX and SBT experiments. A pilot‐scale laboratory reactor was constructed to serve as the Method 304B unit. Biomass from the unit was also used to conduct BOX and modified SBT experiments (modification involved use of a sealed draft‐tube reactor with a headspace recirculation pump instead of a serum bottle) for 1,2‐dichloroethane, diisopropyl ether, methyl tertiary butyl ether, and toluene. Three experimental runs ‐ each consisting of one Method 304B experiment, one BOX experiment, and one modified SBT experiment ‐ were completed. The BOX and SBT data for each run were analyzed using a Monod model, and best‐fit biodegradation kinetic parameters were determined for each experiment, including a first‐order biodegradation rate constant (K1). Experimental results suggest that for readily biodegradable VOCs (i.e., K1 > 10 L/g volatile suspended solids [VSS]•h) the two batch techniques can provide improved means of determining biodegradation rate constants compared with Method 304B. In particular, these batch techniques avoid the Method 304B problem associated with steady‐state effluent concentrations below analytical detection limits. However, experimental results also suggest that the two batch techniques should not be used to determine biodegradation rate constants for slowly degraded VOCs (i.e., K1 < 0.1 L/g VSS•h).

Effect of Soot Build-Up While Sampling with the Volatile Organic Sampling Train (VOST)

The U.S. Environmental Protection Agency's Method 00301, the Volatile Organic Sampling Train (VOST), is used to determine the destruction and removal efficiencies of volatile organic emissions from industrial boilers co-firing hazardous waste. Previous reports detailing a hysteresis effect2,3,4 for volatile organic compounds (VOCs), resulting from soot build-up on the interior surfaces of boilers and industrial furnaces, raised concerns of possible VOST measurement biases due to soot deposits within the VOST. This possibility required laboratory investigation of the method under sooty conditions. Method collection efficiency was evaluated by comparing volatile organic compound levels collected in a control VOST (using a soot-free particulate filter in the sampling probe), to VOC recoveries while using a soot-laden particulate filter in the probe. Emphasis was directed to substances in the upper range of VOC boiling points (120 to 130° C). Statistical evaluation of the data collected indicated that recoveries for two of the higher boiling VOCs (chlorobenzene and octane) appeared to be negatively influenced by the presence of soot on the VOST filter. It is not likely, however, that these findings will have a major impact on previously collected hazardous waste incinerator data, since the VOST-Soot effect was determined at moderately high soot loadings, which are atypical of properly operating hazardous waste incinerators.

Simulated Nitric and Sulfuric Acid Precipitation: The Effects on the Development of Rana pipiens

Simulated Nitric and Sulfuric Acid Precipitation: The Effects on the Development of Rana pipiens