Determining the fate and toxicity of polycyclic aromatic hydrocarbons associated with coal-tar and other carbonaceous material particles in urban lakes

U.S. Department of the InteriorU.S. Geological SurveyOpe

Lignin and Lipid Impact on Sorption and Diffusion of Trichloroethylene in Tree Branches for Determining Contaminant Fate during Plant Sampling and Phytoremediation

Plants Draw All They Need from their Surrounding Environment and in Doing So Also Draw Anthropogenic Contaminants from their Surroundings. Several Natural Processes (E.g., Active Transport, Diffusion, Sorption, and Degradation) Occur within Trees and Affect Chemical Concentrations in Tree Samples. This Study Elucidates Tree Contaminant Chemical Interactions on Equilibrium Sorption and Diffusion into Branch Tissue (I.e., Wood Core and Bark), Specifically the Impacts of Lipid and Lignin Content. Five Tree Species Were Selected to Span a Range of Lignin and Lipid Contents. Linear Isotherms Were Obtained for All Sampled Species over a Limited Concentration Range (2 Μg/ ML \u3c C Gas \u3c 12 Μg/mL), and Equilibrium Distribution Coefficients (Kd) Were Linearly Correlated to Lipid (R2 \u3e 0.83) But Not Lignin (R2 \u3c 0.4) Content. Lipid Content Was Generally Higher in Bark Than in Wood Cores, So Mass Concentrated in This Tissue. Diffusion into Trees Was Modeled, Showing Mass Transfer Resistance in Bark Was Different from Wood Cores. Diffusion Coefficients for Bark Were 2-10 Times Less Than Those for Wood Cores for All Species, and Diffusion Was Linearly Related to Lipid Content (R2 \u3e 0.96) and Sorption Coefficients (R2 \u3e 0.83). Data from This Study and Previous Research Were Used to Develop the Following Correlation between the Diffusion Coefficient and Relevant Plant and Chemical Parameters for Branch Samples: D = (-7 X 10 -11) X [Flipid X 10 (1.48xlogKow+0.54)] + 4 X 10 -8. © 2009 American Chemical Society

Patterns of Genetic Variation in Southern Appalachian Populations of Athyrium filix‐femina var. asplenioides (Dryopteridaceae)

Allozyme variation (17 loci coding 11 enzymes) was investigated in 14 populations of the fern Athyrium filix‐femina var. asplenioides arrayed at differing elevations and latitudes in the southern Appalachians. Allozyme fingerprints showed that asplenioides individuals comprise meandering, overlapping clones usually ≤3 m in extent, occasionally forming larger clones of up to 17 m. Levels of genetic variability in populations (means: , , ) were near the averages for both ferns and seed plants. General conformance to Hardy‐Weinberg expectations indicated a predominantly outcrossing mating system. Hierarchical F statistic analysis and occasional deficits and excesses of heterozygotes indicated population substructure. Similar allele frequencies across all populations resulted in low to moderate values (mean ; ) and high values of genetic similarity (mean ; mean ). Hierarchical analysis indicated that neither regional proximity ( ) nor elevation ( ) contributed substantially to divergence among populations ( ), a result corroborated by UPGMA analysis that clustered together populations from different regions and of different elevational class. Southern Appalachian asplenioides differed from more eastern asplenioides populations of the piedmont and coastal plain in having higher frequencies of Pgm‐2c and Tpi‐2B, alleles characteristic of the more northern variety angustum. Nonetheless, genetic distinctness of the two varieties was maintained. We hypothesize that higher frequencies of angustum alleles in the southern Appalachian asplenioides populations are the result of introgression from angustum that persisted at high elevations as both taxa migrated northward following the retreat of the Wisconsinan glacier

Towards predicting DNAPL source zone formation to improve plume assessment: Using robust laboratory and numerical experiments to evaluate the relevance of retention curve characteristics

© 2020 The Authors We conducted multiple laboratory trials in a robust and repeatable experimental layout to study dense non-aqueous phase liquid (DNAPL) source zone formation. We extended an image processing and analysis framework to derive DNAPL saturation distributions from reflective optical imaging data, with volume balance deviations \u3c 5.07%. We used a multiphase flow model to simulate source zone formation in a Monte Carlo approach, where the parameter space was defined by the variation of retention curve parameters. Integral and geometric measures were used to characterize the source zones and implemented into a multi-criteria objective function. The latter showed good agreement between observation data and simulation results for effective DNAPL saturation values \u3e 0.04, especially for early stages of DNAPL migration. The common hypothesis that parameters defining the DNAPL-water retention curves are constant over time was not confirmed. Once DNAPL pooling started, the optimal fit in the parameter space was significantly different compared to the earlier DNAPL migration stages. We suspect more complex processes (e.g., capillary hysteresis, adsorption) to become relevant during pool formation. Our results reveal deficits in the grayscale-DNAPL saturation relationship definition and laboratory estimation of DNAPL-water retention curve parameters to overcome current limitations to describe DNAPL source zone formation

Carbonaceous material fractions in sediments and their effect on the sorption and persistence of organic pollutants in small urban watersheds

U.S. Department of the InteriorU.S. Geological SurveyOpe

(13) Proposal to designate reproductively competent species of hybrid origin by an × placed in brackets (reword Article H.3 Note 1)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149747/1/tax01103.pd

Reuse of Produced Water from CO2 Enhanced Oil Recovery, Coal-Bed Methane, and Mine Pool Water by Coal-Based Power Plants

Department of Energy, DOE award number DE-NT0005343Ope

2016 ACR-EULAR adult dermatomyositis and polymyositis and juvenile dermatomyositis response criteria-methodological aspects

Objective. The objective was to describe the methodology used to develop new response criteria for adult DM/PM and JDM. Methods. Patient profiles from prospective natural history data and clinical trials were rated by myositis specialists to develop consensus gold-standard ratings of minimal, moderate and major improvement. Experts completed a survey regarding clinically meaningful improvement in the core set measures (CSM) and a conjoint-analysis survey (using 1000Minds software) to derive relative weights of CSM and candidate definitions. Six types of candidate definitions for response criteria were derived using survey results, logistic regression, conjoint analysis, application of conjoint-analysis weights to CSM and published definitions. Sensitivity, specificity and area under the curve were defined for candidate criteria using consensus patient profile data, and selected definitions were validated using clinical trial data. Results. Myositis specialists defined the degree of clinically meaningful improvement in CSM for minimal, moderate and major improvement. The conjoint-analysis survey established the relative weights of CSM, with muscle strength and Physician Global Activity as most important. Many candidate definitions showed excellent sensitivity, specificity and area under the curve in the consensus profiles. Trial validation showed that a number of candidate criteria differentiated between treatment groups. Top candidate criteria definitions were presented at the consensus conference. Conclusion. Consensus methodology, with definitions tested on patient profiles and validated using clinical trials, led to 18 definitions for adult PM/DM and 14 for JDM as excellent candidates for consideration in the final consensus on new response criteria for myositis