133 research outputs found
Evaluation of Biological Treatability of Soil Contaminated with Manufactured Gas Plant Waste
The biological treatability of subsurface soil contaminated with manufactured gas plant (MGP) waste was evaluated. Mineralization assays incorporating 14C-phenanthrene were used to evaluate the biotransformation potential of indigenous microorganisms at the site. Multi-phase laboratory microcosms were used to evaluate the interphase transfer potential and chemical mass distribution of phenanthrene. The Microtox™ bioassay was used to evaluate detoxification trends at the site. Mineralization results indicated that indigenous microorganisms at the site were capable of transforming phenanthrene, a component of coal-tar creosote. Results also indicated that spiked 14C-phenanthrene mineralization was influenced by nutrient addition and by the amount of contamination. The chemical mass distribution of 14C-phenanthrene indicated that volatilization may be an important transport mechanism for chemicals residing in, or migrating to the vadose zone of soil. Following removal of the coal-tar waste source at the site, the toxicity of water soluble extracts of the site soil decreased to a non-toxic response based upon Microtox™ assay results. Parent compound concentrations at the site also decreased with time subsequent to source removal. Results of this study indicate that natural in situ bioremediation may be an important treatment process at a former manufactured gas plant waste site in New York
Diffusion and viscosity in a supercooled polydisperse system
We have carried out extensive molecular dynamics simulations of a supercooled
polydisperse Lennard-Jones liquid with large variations in temperature at a
fixed pressure. The particles in the system are considered to be polydisperse
both in size and mass. The temperature dependence of the dynamical properties
such as the viscosity () and the self-diffusion coefficients () of
different size particles is studied. Both viscosity and diffusion coefficients
show super-Arrhenius temperature dependence and fit well to the well-known
Vogel-Fulcher-Tammann (VFT) equation. Within the temperature range
investigated, the value of the Angell's fragility parameter (D )
classifies the present system into a strongly fragile liquid. The critical
temperature for diffusion () increases with the size of the
particles. The critical temperature for viscosity () is larger than
that for the diffusion and a sizeable deviations appear for the smaller size
particles implying a decoupling of translational diffusion from viscosity in
deeply supercooled liquid. Indeed, the diffusion shows markedly non-Stokesian
behavior at low temperatures where a highly nonlinear dependence on size is
observed. An inspection of the trajectories of the particles shows that at low
temperatures the motions of both the smallest and largest size particles are
discontinuous (jump-type). However, the crossover from continuous Brownian to
large length hopping motion takes place at shorter time scales for the smaller
size particles.Comment: Revtex4, 7 pages, 8 figure
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Temperature dependence of protein dynamics simulated with three different water models
The effect of variation of the water model on the temperature dependence of protein and hydration water dynamics is examined by performing molecular dynamics simulations of myoglobin with the TIP3P, TIP4P, and TIP5P water models and the CHARMM protein force field at temperatures between 20 and 300 K. The atomic mean-square displacements, solvent reorientational relaxation times, pair angular correlations between surface water molecules, and time-averaged structures of the protein are all found to be similar, and the protein dynamical transition is described almost indistinguishably for the three water potentials. The results provide evidence that for some purposes changing the water model in protein simulations without a loss of accuracy may be possible
Direct Functionalization of (Un)protected Tetrahydroisoquinoline and Isochroman under Iron and Copper Catalysis: Two Metals, Two Mechanisms
IrrE, a Global Regulator of Extreme Radiation Resistance in Deinococcus radiodurans, Enhances Salt Tolerance in Escherichia coli and Brassica napus
Mechanisms underlying electro-mechanical dysfunction in the Zucker diabetic fatty rat heart: a model of obesity and type 2 diabetes
Diabetes mellitus (DM) is a major and worsening global health problem, currently affecting over 450 million people and reducing their quality of life. Type 2 diabetes mellitus (T2DM) accounts for more than 90% of DM and the global epidemic of obesity, which largely explains the dramatic increase in the incidence and prevalence of T2DM in the past 20 years. Obesity is a major risk factor for DM which is a major cause of morbidity and mortality in diabetic patients. The electro-mechanical function of the heart is frequently compromised in diabetic patients. The aim of this review is to discuss the pathophysiology of electro-mechanical dysfunction in the diabetic heart and in particular, the Zucker diabetic fatty (ZDF) rat heart, a well-studied model of T2DM and obesity
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Strategy for Assessing Impacts of Power Plants on Fish and Shellfish Populations
From executive summary: Many guidance documents are available for conducting impact assessments at power plants, but none adequately address the problems of study design, implementation, and evaluation, particularly as they relate to assessing impacts on fish and shellfish populations. This lack of guidance frequently results in the acquisition of irrelevant or extraneous information. Since the regulatory and coordinating agencies (such as the U.S. Fish and Wildlife Service) must review and evaluate power plant impact assessments, a strategy has been developed which, if implemented, will enhance the collection of relevant data and the reliability of conclusions related to predicted or measured impacts. The strategy was designed for use by biologists responsible for conducting or reviewing assessments of impacts on fish and shellfish. Rather than a \u27cookbook\u27 recipe for performing an \u27ideal\u27 impact assessment, this is a generic strategy that promotes consistency and uniformity in the design and performance of aquatic ecological impact assessments. The result of following this strategy should be the collection of information amenable to utility company and regulatory decision-making procedures
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Survey of biomedical and environental data bases, models, and integrated computer systems at Argonne National Laboratory
This document contains an inventory (index) of information resources pertaining to biomedical and environmental projects at Argonne National Laboratory--the information resources include a data base, model, or integrated computer system. Entries are categorized as models, numeric data bases, bibliographic data bases, or integrated hardware/software systems. Descriptions of the Information Coordination Focal Point (ICFP) program, the system for compiling this inventory, and the plans for continuing and expanding it are given, and suggestions for utilizing the services of the ICFP are outlined
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